WO2023042695A1 - Rendering device and rendering method - Google Patents

Rendering device and rendering method Download PDF

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Publication number
WO2023042695A1
WO2023042695A1 PCT/JP2022/033214 JP2022033214W WO2023042695A1 WO 2023042695 A1 WO2023042695 A1 WO 2023042695A1 JP 2022033214 W JP2022033214 W JP 2022033214W WO 2023042695 A1 WO2023042695 A1 WO 2023042695A1
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WO
WIPO (PCT)
Prior art keywords
ink
inkjet head
head
pinning
ejected
Prior art date
Application number
PCT/JP2022/033214
Other languages
French (fr)
Japanese (ja)
Inventor
徹 牧野
Original Assignee
コニカミノルタ株式会社
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Filing date
Publication date
Application filed by コニカミノルタ株式会社 filed Critical コニカミノルタ株式会社
Publication of WO2023042695A1 publication Critical patent/WO2023042695A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J3/00—Typewriters or selective printing or marking mechanisms characterised by the purpose for which they are constructed
    • B41J3/407—Typewriters or selective printing or marking mechanisms characterised by the purpose for which they are constructed for marking on special material
    • B41J3/4073—Printing on three-dimensional objects not being in sheet or web form, e.g. spherical or cubic objects
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C5/00—Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C9/00—Apparatus or plant for applying liquid or other fluent material to surfaces by means not covered by any preceding group, or in which the means of applying the liquid or other fluent material is not important
    • B05C9/08—Apparatus or plant for applying liquid or other fluent material to surfaces by means not covered by any preceding group, or in which the means of applying the liquid or other fluent material is not important for applying liquid or other fluent material and performing an auxiliary operation
    • B05C9/14—Apparatus or plant for applying liquid or other fluent material to surfaces by means not covered by any preceding group, or in which the means of applying the liquid or other fluent material is not important for applying liquid or other fluent material and performing an auxiliary operation the auxiliary operation involving heating or cooling
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00—Processes for applying liquids or other fluent materials
    • B05D1/26—Processes for applying liquids or other fluent materials performed by applying the liquid or other fluent material from an outlet device in contact with, or almost in contact with, the surface
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
    • B05D7/24—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials for applying particular liquids or other fluent materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J11/00—Devices or arrangements  of selective printing mechanisms, e.g. ink-jet printers or thermal printers, for supporting or handling copy material in sheet or web form
    • B41J11/0015—Devices or arrangements  of selective printing mechanisms, e.g. ink-jet printers or thermal printers, for supporting or handling copy material in sheet or web form for treating before, during or after printing or for uniform coating or laminating the copy material before or after printing
    • B41J11/002—Curing or drying the ink on the copy materials, e.g. by heating or irradiating
    • B41J11/0021—Curing or drying the ink on the copy materials, e.g. by heating or irradiating using irradiation
    • B41J11/00214—Curing or drying the ink on the copy materials, e.g. by heating or irradiating using irradiation using UV radiation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/17—Ink jet characterised by ink handling
    • B41J2/18—Ink recirculation systems

Definitions

  • the present invention relates to a drawing apparatus and a drawing method for drawing by ejecting ink.
  • a multi-axis robot arm equipped with an inkjet head has been utilized for coloring, drawing, etc. on a three-dimensional object (see, for example, Patent Document 1).
  • the multi-axis robot arm can effectively position the inkjet head on the surface of the object, and the inkjet head has the advantage of suppressing the generation of mist that scatters without adhering to the object. .
  • An object of the present invention is to provide a drawing apparatus and drawing method that enable good drawing.
  • the invention according to claim 1 provides a drawing apparatus, inkjet head, a robot arm that holds the inkjet head; a pinning device that thickens the ink ejected from the inkjet head; characterized by comprising
  • the invention according to claim 2 is the drawing apparatus according to claim 1,
  • the pinning device is characterized by increasing the viscosity of the ink ejected from the inkjet head on the surface of the object to be drawn.
  • the invention according to claim 3 is the drawing apparatus according to claim 1 or claim 2,
  • the pinning device is held by the robot arm together with the inkjet head.
  • the invention according to claim 4 is the drawing apparatus according to any one of claims 1 to 3, It is characterized by comprising a distance control unit for controlling the robot arm so that the distance from the nozzle of the inkjet head to the object to be drawn becomes a target value.
  • the invention according to claim 5 is the drawing apparatus according to any one of claims 1 to 4,
  • the inkjet head has a plurality of nozzles arranged side by side, It is characterized by comprising a nozzle selection control section that regulates ejection of nozzles whose distance to the object to be drawn deviates from a target value.
  • the invention according to claim 6 is the drawing apparatus according to any one of claims 1 to 5, It is characterized by comprising an attitude control section for controlling the robot arm so that the inkjet head ejects ink in a direction facing the surface of the object to be drawn.
  • the invention according to claim 7 is the drawing apparatus according to any one of claims 1 to 6, It is characterized by comprising an adjusting mechanism for adjusting the tilt angle of the object to be drawn.
  • the invention according to claim 8 is the drawing apparatus according to any one of claims 1 to 7,
  • the pinning device is an irradiation device that irradiates the ejected ink with an energy beam.
  • the invention according to claim 9 is the drawing apparatus according to claim 8,
  • the pinning device is an irradiation device that irradiates the ejected ink with energy rays of infrared rays, ultraviolet rays, or excimer emission.
  • the invention according to claim 10 is the drawing apparatus according to any one of claims 1 to 7,
  • the pinning device is a heating device that heats the ejected ink.
  • the invention according to claim 11 is the drawing apparatus according to any one of claims 1 to 10, It is characterized by comprising a temperature adjusting section that adjusts the temperature of the ink before it is ejected from the inkjet head.
  • the invention according to claim 12 is the drawing apparatus according to any one of claims 1 to 11,
  • the ink is characterized by containing at least one of an ultraviolet curing agent, an ultraviolet absorber and a gelling agent.
  • the invention according to claim 13 is the drawing apparatus according to any one of claims 1 to 12,
  • the ink is characterized by having thixotropic properties such that the viscosity is 200 [mPa ⁇ s] or less at a shear rate of 1000 [1/s].
  • the invention according to claim 14 is the drawing apparatus according to claim 13, It is characterized by comprising a circulation structure that circulates the ink supplied to the nozzles of the inkjet head at a shear rate of 1000 [1/s] or more.
  • the invention according to claim 15 is the drawing apparatus according to claim 14,
  • the ink circulation amount of the circulation structure is 30 [ml/min] or more.
  • the invention according to claim 16 is the drawing apparatus according to any one of claims 1 to 15,
  • the robot arm holds the inkjet head and the pinning device together,
  • the pinning device performs control to increase the viscosity of the ink from the rear side of the inkjet head with respect to the traveling direction of the inkjet head.
  • First drawing control A part is provided.
  • the invention according to claim 17 is the drawing apparatus according to any one of claims 1 to 15, the robot arm holds two pinning devices on opposite sides of the inkjet head; When drawing is performed by scanning the inkjet head in one direction parallel to a predetermined scanning direction, from the pinning device behind the inkjet head with respect to the traveling direction of the inkjet head in the one direction thicken the ink, When drawing is performed by scanning the inkjet head in a direction opposite to the one direction parallel to the scanning direction, the ink jet head located behind the inkjet head with respect to the traveling direction of the inkjet head in the opposite direction. It is characterized by comprising a second drawing control section that controls to increase the viscosity of the ink from the pinning device.
  • the invention according to claim 18 is the drawing apparatus according to any one of claims 1 to 15,
  • the robot arm holds the two inkjet heads on both sides of the pinning device,
  • the ink is ejected from the inkjet head located in front of the pinning device with respect to the traveling direction of the inkjet head in the one direction.
  • the inkjet head is on the front side of the pinning device with respect to the traveling direction of the inkjet head in the opposite direction. It is characterized by comprising a third drawing control unit that controls to eject ink from the head.
  • Drawing is performed using the drawing apparatus according to claim 1.
  • the invention according to claim 20 is the drawing method according to claim 19, the ink comprises a gelling agent; A temperature difference is provided between the ink before it is ejected from the inkjet head and the object to be drawn, and gelling of the ink adhering to the object to be drawn is promoted.
  • the present invention can suppress the occurrence of dripping and perform good drawing.
  • FIG. 1 is a side view showing the overall configuration of a drawing apparatus that is an embodiment of the present invention
  • Front view of drawing device Bottom view of head unit Perspective view of inkjet head
  • Cross-sectional view of an inkjet head Disassembled perspective view of inkjet head
  • Disassembled perspective view of head chip Top view of pressure chamber substrate Bottom view of the pressure chamber substrate Plan view of channel spacer substrate
  • Bottom view of channel spacer substrate Plan view of nozzle substrate
  • FIG. 4 is a side view showing the relationship between the target position of ink ejection by the inkjet head and the near-infrared irradiation position of the pinning device; Block diagram showing the main functional configuration of the drawing device Explanatory drawing of the ejection control of the inkjet head by the nozzle selection control unit.
  • FIG. 1 is a side view showing the overall configuration of a drawing apparatus 300 according to an embodiment of the present invention
  • FIG. 2 is a front view (however, FIG. 2 shows a state in which a head unit 224, which will be described later, faces downward).
  • the drawing apparatus 300 includes a head unit 224 having a plurality of inkjet heads 100, a robot arm 310 that holds the head unit 224, a pinning device 320 that thickens the ink ejected from the inkjet heads 100, and each of these components. and a chamber 330 for storing a workpiece W (see FIGS. 14 and 16) as an object to be patterned, and a controller 240 for controlling the operation of each of the components described above.
  • the robot arm 310 includes a base 311 as a base, a plurality of arms 312 connected by joints 313, servo motors as drive sources provided for each joint, and arms rotated or rotated by each servo motor. It is a vertically articulated robot arm equipped with encoders for detecting angles, and an inkjet head 100 and a pinning device 320 are held at the tips of a plurality of arms 312 connected by joints 313 .
  • Each of the joints 313 is either a rocking joint that pivotally supports one end of the arm 312 and pivots the other end, or a rotary joint that pivotally supports the arm 312 itself so that it can rotate about its longitudinal direction.
  • the robot arm 310 has six joints 313, and can position the inkjet head 100 and the pinning device 320 at the tip of the arm 310 at arbitrary positions and take arbitrary postures. Therefore, the robot arm 310 can scan the head unit 224 along an arbitrary curved line on the three-dimensional curved surface of the work W to perform drawing. In the present embodiment, “scanning” means drawing while moving the head unit 224 .
  • the robot arm 310 is not limited to 6-axis, and a 7-axis arm having 7 joints may be adopted.
  • the inkjet head 100 and the pinning device 320 can be positioned at arbitrary positions, and the intermediate joints can be moved while taking arbitrary postures. Interference with other surrounding objects can be avoided. Therefore, the inkjet head 100 and the pinning device 320 can be positioned at arbitrary positions in a wider range and can be made to assume arbitrary postures.
  • the chamber 330 is a storage room that stores the robot arm 310 and the workpiece W in a sealed state.
  • a workbench 331 on which the work W is placed is provided inside the chamber 330 .
  • a jig for holding the workpiece W in a predetermined posture may be provided on the workbench 331 .
  • the inside of the chamber 330 can be blocked from the outside air to be dustproof and moistureproof.
  • FIG. 3 is a bottom view of the head unit 224 viewed from the ink ejection direction of the inkjet head 100.
  • the drawing width direction which is the arrangement direction of the nozzles 111 of the inkjet head 100, is defined as the left-right direction, and the direction of ejection from the nozzles 111 is perpendicular to the direction of ejection.
  • a direction orthogonal to the left-right direction is defined as a front-rear direction (also referred to as a scanning direction), and a direction orthogonal to the left-right direction and the front-rear direction (ejection direction) is defined as an up-down direction.
  • these front, back, left, right, up, and down directions are directions in which the head unit 224 is determined with respect to the inkjet head 100, and do not match the front, back, left, right, up, and down directions in the description of the robot arm 310 described above.
  • the arrows in the flow path of the inkjet head 100 indicate the direction of ink flow.
  • " ⁇ " is used to mean that the numerical values before and after it are included as the lower limit and the upper limit.
  • the head unit 224 is a unit formed by integrally holding a plurality of inkjet heads 100 with their ejection directions aligned. As shown in FIG. 3, the head unit 224 has two rows of ink jet heads 100 arranged in the horizontal direction in two rows. In the head unit 224, the inkjet heads 100 are staggered so that the nozzles 111 of the inkjet heads 100 in the front row and the nozzles 111 of the inkjet heads 100 in the rear row do not overlap when viewed from the front-rear direction. are placed. As a result, the head unit 224 constitutes a line head, and performs one-pass drawing with lines extending in the left-right direction. Note that the number of rows and columns of the inkjet heads 100 is an example, and is not limited to the above description.
  • FIG. 6 shows the head chip 1
  • FIGS. 7A and 7B show the pressure chamber substrate 13
  • FIGS. 8A and 8B show the channel spacer substrate 12
  • FIG. 10A, 10B, 11A and 11B show the head chip 1.
  • FIG. 7B is described as a bottom view of the pressure chamber substrate 13, strictly speaking, it is not a bottom view, but a view of the bottom surface of the pressure chamber substrate 13 seen through from above.
  • FIG. 8B is not strictly a bottom view, but is a view of the bottom face of the channel spacer substrate 12 seen through from above.
  • the ink jet head 100 includes a head chip 1, a wiring board 2 on which the head chip 1 is arranged, and a wiring board 2 and a flexible board 3 which are connected to each other.
  • a drive circuit board 4 a manifold 5 for storing ink to be supplied to the pressure chambers 131 in the head chip 1, a housing 6 in which the manifold 5 is accommodated, and a bottom opening of the housing 6 are attached so as to close the opening.
  • a cap receiving plate 7 mounted on the housing 6, a cover member 9 attached to the housing 6, and the like are provided.
  • illustration of the manifold 5 is omitted in FIG. 4A, and illustration of the cover member 9 is omitted in FIGS. 4B and 5 .
  • an example in which the number of rows of the nozzles 111 of the head chip 1 is four will be described. may be any one of 1 to 3 columns, or may be 5 or more columns.
  • the head chip 1 is a substantially square prism-shaped member elongated in the left-right direction, and is constructed by laminating a pressure chamber substrate 13, a channel spacer substrate 12, and a nozzle substrate 11 in order (FIGS. 6 to 8). 11B).
  • the pressure chamber substrate 13 is provided with pressure chambers 131, air chambers 132, a common ink discharge path 133, and the like (see FIGS. 6, 7A, 7B, etc.).
  • a large number of pressure chambers 131 and air chambers 132 are provided so as to be alternately arranged in the left-right direction, and are provided in four rows in the front-rear direction.
  • the pressure chamber 131 has a substantially rectangular cross section and is formed along the vertical direction, and has an inlet on the upper surface of the pressure chamber substrate 13 and an outlet on the lower surface.
  • the pressure chamber 131 communicates with the ink reservoir 51 at its upper end, and ink is supplied from the ink reservoir 51 to the pressure chamber 131 and ejected from the nozzle 111 into the pressure chamber 131 .
  • the pressure chamber 131 is formed along the vertical direction so as to have a substantially rectangular cross section with the same area, straddling the pressure chamber substrate 13 and the channel spacer substrate 12. It communicates with the nozzle 111 (see FIGS. 10A, 10B, etc.).
  • the air chamber 132 has a substantially rectangular cross section slightly larger than the pressure chamber 131 and is formed parallel to the pressure chamber 131 along the vertical direction. Also, unlike the pressure chamber 131 , the air chamber 132 is not communicated with the ink reservoir 51 , so that ink does not flow into the air chamber 132 . Also, the air chamber 132 is not communicated with the nozzle 111 (see FIGS. 10A, 10B, etc.).
  • the pressure chamber 131 and the air chamber 132 are separated by a partition wall 136 as a pressure generating means made of piezoelectric material (see FIG. 11A).
  • a drive electrode (not shown) is provided on the partition 136, and the partition 136 and the drive electrode constitute an actuator.
  • the partition wall 136 portion between the adjacent pressure chambers 131 repeats shear mode displacement, thereby applying pressure to the ink in the pressure chambers 131 .
  • the pressure chambers 131 located at the ends in the left-right direction, which have partition walls 136 only on one side, are not used, and the other pressure chambers 131 have partition walls 136 on both sides.
  • a pressure chamber 131 is used.
  • meniscus oscillation Meniscus rocking continuously reciprocates the volume of the pressure chamber 131 within a certain range based on the rocking waveform, and without ejecting ink, the meniscus (bent interface) formed by the ink in the nozzle 111 and the nozzle 111 . Among them, the ink in the pressure chamber 131 is vibrated.
  • the “fluctuation waveform” is a drive pulse weaker than the contraction pulse for ejecting droplets, and is a contraction or expansion pulse that contracts or expands the volume of the pressure chamber within a range where only pressure waves are generated.
  • the actuator (partition wall 136, drive electrode, etc.) that applies pressure to the ink in the pressure chamber 131 has a lower voltage than the drive waveform for ejecting the ink from the nozzle 111, and the pressure of the ink in the pressure chamber 131 is reduced.
  • a rocking waveform is applied to oscillate the interface.
  • the pressure chambers 131 may be formed without the air chambers 132, it is preferable to alternately provide the pressure chambers 131 and the air chambers 132 as described above. As a result, the pressure chambers 131 can be prevented from being adjacent to each other, so that when the partition wall 136 adjacent to one pressure chamber 131 is deformed, the other pressure chambers 131 are not affected.
  • the common ink discharge path 133 is configured by connecting a first common ink discharge path 134 and a second common ink discharge path 135 (see FIGS. 6 and 7B, etc.).
  • the first common ink discharge path 134 is formed on the lower surface side of the pressure chamber substrate 13 so as to avoid the portion where the pressure chambers 131 and the air chambers 132 are provided, and extends on the front and rear sides of the head chip 1 and their central portions. , are provided along the left-right direction in three rows.
  • a plurality of individual ink discharge paths 121 provided on the channel spacer substrate 12 are connected to the lower surface side of the first common ink discharge path 134, and these individual ink discharge paths 121 (second individual ink discharge paths 123 ) can merge in the first common ink discharge path 134 (FIGS. 7B, 8A and 10A).
  • the first common ink discharge path 134 is connected near the right end to a second common ink discharge path 135 capable of discharging ink to the outside of the head chip 1 . Therefore, the first common ink discharge path 134 serves as a flow path through which the ink flowing from the individual ink discharge path 121 (the second individual ink discharge path 123) flows toward the second common ink discharge path 135. .
  • the second common ink discharge path 135 is formed along the vertical direction, like the pressure chambers 131 .
  • the second common ink discharge path 135 communicates with the first common ink discharge path 134 on the lower surface side of the pressure chamber substrate 13, and communicates with the discharge liquid chamber 57 on the upper surface side of the pressure chamber substrate 13. It is a flow path for discharging the ink flowing from 134 toward the upper side (the side opposite to the nozzle substrate 11 side) to the outside of the head chip 1 .
  • the second common ink discharge path 135 is provided near the right end of the head chip 1 and communicates with the first common ink discharge path 134 . Further, by providing the second common ink discharge path 135 so as to have a volume larger than that of the individual pressure chambers 131, the ink discharge efficiency can be improved.
  • Pressure chambers 131 and individual ink discharge paths 121 branched from the pressure chambers 131 are formed in the channel spacer substrate 12 (see FIGS. 10A and 10B, etc.).
  • the pressure chambers 131 are formed along the vertical direction so as to straddle the channel spacer substrate 12 and the pressure chamber substrate 13 and have substantially rectangular cross sections with the same area.
  • One end of the individual ink discharge path 121 is connected to the pressure chamber 131 and the other end is connected to the first common ink discharge path 134 to discharge the ink in the pressure chamber 131 to the first common ink discharge path 134 . It is a flow channel.
  • Two or more individual ink discharge paths 121 are provided with respect to the ejection opening of the nozzle 111 from the viewpoint of facilitating the discharge of air bubbles, foreign substances, etc. together with the ink. That is, at least two individual ink discharge paths 121 are provided in each pressure chamber 131 . Also, as shown in FIGS.
  • two individual ink discharge paths 121 are provided one each in the forward direction and the rearward direction of the pressure chamber 131 to discharge air bubbles, foreign matters, etc. together with the ink. It is preferable because it is possible to obtain the effect of facilitating production and the production efficiency is high.
  • the flow path spacer substrate 12 is made of silicone, stainless steel, etc., from the viewpoints that the individual ink discharge paths 121 can be easily processed (with high precision) and that the temperature of the ink can be easily kept uniform due to its high thermal conductivity.
  • a substrate made of steel (SUS) or 42 alloy is preferred. Among these, it is preferable to use a substrate made of a material having a coefficient of thermal expansion close to that of the material forming the pressure chamber substrate 13 .
  • the nozzle substrate 11 is provided with a nozzle 111 which is a hole penetrating in the thickness direction (vertical direction) (see FIG. 9).
  • the nozzle 111 communicates with the pressure chamber 131 and serves as an ejection opening (ejection opening) for ejecting the ink stored in the pressure chamber 131 when pressure is applied to the ink in the pressure chamber 131 .
  • the nozzles 111 in this embodiment are arranged in the horizontal direction and form four rows in the front-rear direction.
  • the nozzle substrate 11 preferably constitutes one of the channel walls of the first individual ink discharge channel 122 .
  • the nozzle substrate 11 since the nozzle substrate 11 is thin, it can function as a damper capable of changing the volume of the flow path by slightly elastically deforming due to pressure.
  • the nozzle substrate 11 is preferably made of polyimide resin, polyethylene terephthalate resin, polyamide resin, polysulfone resin, or the like. Accordingly, the nozzle substrate 11 can be manufactured by processing the resin substrate with high accuracy by laser processing, and the nozzle substrate 11 has excellent ink resistance, which is preferable. Moreover, since these resin substrates have high elasticity, they can be suitably used as the channel walls of the first individual ink supply channels. The nozzle substrate 11 can also be manufactured by etching a silicone substrate.
  • a protective film having ink resistance is formed on the flow path surfaces of the pressure chambers 131, the individual ink discharge paths 121, and the common ink discharge path 133, which serve as ink flow paths in the head chip 1.
  • the protective film is not particularly limited as long as it has ink resistance.
  • the parylene film is a resin film made of a paraxylylene resin or a derivative resin thereof, and may be formed, for example, by a chemical vapor deposition (CVD) method using a solid di-paraxylylene dimer or a derivative thereof as a vapor deposition source. can be done. That is, the para-xylylene radicals generated by the vaporization and thermal decomposition of the di-para-xylylene dimer are adsorbed on the surface of the flow channel member and the metal layer, undergo a polymerization reaction, and form a film.
  • CVD chemical vapor deposition
  • Parylene films include parylene films having various performances, and depending on the required performance, various parylene films and multi-layered parylene films in which a plurality of these various parylene films are laminated are used as desired parylene films. can also be applied.
  • the layer thickness of the parylene film is preferably in the range of 5 to 20 ⁇ m from the viewpoint of obtaining excellent insulation and ink resistance effects.
  • Poly-para-xylylene is a crystalline polymer with a molecular weight as high as 500,000, and the raw material para-xylylene dimer is sublimated and thermally decomposed to generate para-xylylene radicals.
  • Para-xylylene radicals attach to the spacer substrate and simultaneously polymerize to form poly-para-xylylene to form a protective film.
  • polyparaxylylene examples include Parylene N (trade name of Japan Parylene Co., Ltd.).
  • polyparaxylylene derivatives include Parylene C (trade name of Nippon Parylene Co., Ltd.) in which one chlorine atom is substituted on the benzene ring, and Parylene D (Nippon Parylene (trade name, manufactured by Nippon Parylene Co., Ltd.), and Parylene HT (trade name, manufactured by Japan Parylene Co., Ltd.) in which hydrogen atoms of methylene groups connecting benzene rings are substituted with fluorine atoms.
  • parylene N or parylene C is used as the polyparaxylylene and the polyparaxylylene derivative of the present embodiment from the viewpoint of obtaining the effects of excellent insulation and ink resistance with the above-described layer thickness. is preferred.
  • the first individual ink discharge path 122 in this embodiment is provided on the lower surface side portion of the flow path spacer substrate 12, it is not limited to this.
  • the first individual ink discharge path 122 may be provided across both the nozzle substrate 11 and the flow path spacer substrate 12, may be provided only on the nozzle substrate 11, or may be provided on the bottom surface of the flow path spacer substrate 12. It may be provided slightly above the nozzle substrate 11 so as not to be adjacent to the nozzle substrate 11 .
  • a wiring board 2 is arranged on the upper surface of the head chip 1, and two flexible boards 3 connected to a driving circuit board 4 are provided on both edges of the wiring board 2 along the front-rear direction. are arranged.
  • the wiring board 2 is formed in a substantially rectangular plate shape elongated in the left-right direction, and has an opening 22 in its substantially central portion.
  • the widths of the wiring board 2 in the left-right direction and the width in the front-rear direction are formed to be larger than those of the head chip 1 .
  • the opening 22 is formed in a substantially rectangular shape elongated in the left-right direction.
  • the outlet of the ink discharge path 135 is exposed upward.
  • the flexible board 3 electrically connects the driving circuit board 4 and the electrode part of the wiring board 2, and the signal from the driving circuit board 4 is provided to the partition wall 136 in the head chip 1 through the flexible board 3. can be applied to the drive electrodes.
  • the lower end of the manifold 5 is attached and fixed to the outer edge of the wiring board 2 by adhesion. That is, the manifold 5 is arranged on the inlet side (upper side) of the pressure chamber 131 of the head chip 1 and connected to the head chip 1 via the wiring substrate 2 .
  • the manifold 5 is a member molded from resin, is provided above the pressure chambers 131 of the head chip 1, and stores ink introduced into the pressure chambers 131.
  • the manifold 5 is elongated in the left-right direction, and includes a hollow main body portion 52 that forms an ink reservoir 51 and a hollow main body portion 52 that forms an ink flow path. 1st to 4th ink ports 53 to 56 are provided.
  • the ink reservoir 51 is divided into two chambers, a first liquid chamber 51a on the upper side and a second liquid chamber 51b on the lower side, by a filter F for removing dust in the ink.
  • the first ink port 53 communicates with the upper right end of the first liquid chamber 51 a and is used to introduce ink into the ink reservoir 51 .
  • a first joint 81a is externally inserted at the tip of the first ink port 53.
  • the second ink port 54 communicates with the upper left end of the first liquid chamber 51a and is used to remove air bubbles in the first liquid chamber 51a.
  • a second joint 81b is externally fitted to the tip of the second ink port 54.
  • the third ink port 55 communicates with the upper left end of the second liquid chamber 51b and is used to remove air bubbles in the second liquid chamber 51b.
  • a third joint 82 a is externally inserted at the tip of the third ink port 55 .
  • the fourth ink port 56 communicates with a discharge liquid chamber 57 that communicates with the second common ink discharge path 135 of the head chip 1, and the ink discharged from the head chip 1 passes through the fourth ink port 56 to the inkjet printer. It is discharged outside the head 100 .
  • the housing 6 is, for example, a member formed by die casting using aluminum as a material, and is elongated in the left-right direction.
  • the housing 6 is formed so as to accommodate the manifold 5 to which the head chip 1, the wiring substrate 2 and the flexible substrate 3 are attached, and the bottom of the housing 6 is open.
  • Mounting holes 68 for mounting the housing 6 to the main body of the printer are formed at both ends of the housing 6 in the left-right direction.
  • the cap receiving plate 7 has an elongated nozzle opening 71 formed in a substantially central portion thereof in the left-right direction. It is installed so as to close the bottom opening.
  • FIG. 12 is a schematic diagram showing the ink circulation device 8.
  • the inkjet head 100 is also provided with an ink circulation device 8 as a circulation structure that is particularly suitable for using thixotropic ink that has a low viscosity immediately before ejection and a high viscosity after ejection.
  • the ink circulation device 8 can circulate ink through the first common ink discharge path 134 and the second common ink discharge path 135 to the ejection openings of the nozzles 111 .
  • the ink circulation device 8 controls the average shear velocity in the flow path communicating with the nozzles in the pressure chamber to be 1000 [1/s] or more and 10000 [1/s] or less.
  • the average shear rate refers to the average shear rate during circulation, not during discharge.
  • the “channel communicating with the nozzle” refers to the channel in the vicinity of the nozzle in the pressure chamber 131, as indicated by symbol R in FIG. 10A.
  • the “channel near the nozzle” refers to the channel configured by the channel components closest to the nozzle, specifically the channel R configured by the channel spacer substrate 12 .
  • the ink circulation device 8 controls the average shear rate in the flow path communicating with the nozzle 111 to be the shear rate set in the range of 1000 to 10000 [1/s].
  • means for controlling the average shear rate within the above range include, for example, controlling the circulating flow rate Q of all the nozzles.
  • the circulation flow rate Q can be calculated by the following formula, in order to control the circulation flow rate Q, the first and fourth ink ports 53 and 56 (Fig. 12) (the differential pressure between the INLET and the OUTLET of the head).
  • control unit 240 controls the pressure applied to the pump 88 of the ink circulation device 8, the amount of ink filled in each of the sub-tanks 81 and 82, and the vertical (gravitational) position of each of the sub-tanks 81 and 82. are appropriately changed to adjust the pressure P1 and the pressure P2, and the ink flow rate (circulation flow rate Q) communicating with the nozzles is controlled by the pressure difference (circulation differential pressure ⁇ P) between the pressures P1 and P2.
  • Circulation flow rate Q Circulation differential pressure ⁇ P / Head channel resistance R (The circulating differential pressure ⁇ P represents the circulating differential pressure in the first and fourth ink ports 53 and 56. The head flow path resistance is the flow path resistance from the fourth ink port 56 to the first ink port 53. show)
  • the ink circulation device 8 is an ink supply means for generating a circulation flow of ink from the pressure chambers 131 in the inkjet head 100 to the individual ink discharge paths 121 .
  • the ink circulation device 8 is composed of a supply sub-tank 81, a circulation sub-tank 82, a main tank 83, and the like (see FIG. 12).
  • the supply sub-tank 81 is filled with ink to be supplied to the ink reservoir 51 of the manifold 5 and is connected to the first ink port 53 by an ink flow path 84 .
  • the circulation sub-tank 82 is filled with the ink discharged from the discharge liquid chamber 57 of the manifold 5 and is connected to the fourth ink port 56 by the ink channel 85 .
  • the supply sub-tank 81 and the circulation sub-tank 82 are provided at different positions in the vertical direction (gravitational direction) with respect to the nozzle surface of the head chip 1 (hereinafter also referred to as the "position reference plane").
  • a pressure P1 due to a water head difference between the position reference plane and the supply sub-tank 81 and a pressure P2 due to a water head difference between the position reference plane and the circulation sub-tank 82 are generated.
  • the supply sub-tank 81 and the circulation sub-tank 82 are connected by an ink flow path 86 . Then, the pressure applied by the pump 88 can return the ink from the circulation sub-tank 82 to the supply sub-tank 81 .
  • the main tank 83 is filled with ink to be supplied to the supply sub-tank 81 and is connected to the supply sub-tank 81 by an ink flow path 87 . Ink can be supplied from the main tank 83 to the supply sub-tank 81 by the pressure applied by the pump 89 .
  • the pressure P1 and the pressure P2 can be adjusted by appropriately changing the amount of ink filled in each sub-tank and the position of each sub-tank in the vertical direction (the direction of gravity).
  • the pressure difference between the pressures P1 and P2 allows the ink in the inkjet head 100 to circulate at an appropriate circulation flow rate.
  • the control unit 240 controls the pressure difference between the pressure P1 and the pressure P2 so that the ink circulation rate is 30 [ml/min] or more and 300 [ml/min] or less.
  • the ink circulation device 8 As an example of the ink circulation device 8, the method of controlling the circulation of ink by using the difference in water head has been described, but it is naturally possible to make appropriate modifications as long as the configuration is capable of generating a circulating flow of ink.
  • the head unit 224 may be provided with a temperature adjustment device 226 as a temperature adjustment section that heats and adjusts the temperature of the ink before ejection supplied to the nozzles 111 (see FIG. 15).
  • the temperature adjustment device 226 has a temperature controllable heater and a temperature detection element.
  • the heater is provided at a position that can heat the ink in the ink flow path or tank on the upstream side of the nozzle 111 .
  • the temperature detection element is provided near the heater or nearer the nozzle 111 than the heater, and detects the temperature of the ink supplied to the nozzle 111 .
  • the output of the heater is controlled by the controller 240 so that the temperature of the ink reaches a predetermined temperature based on the detection of the temperature detection element. As a result, the ink immediately before being ejected from the nozzles 111 can be adjusted to the appropriate target temperature.
  • FIG. 13 is a perspective view of the pinning device 320.
  • the pinning device 320 is held at the tip of the robot arm 310 together with the head unit 224 and consists of an irradiation device that irradiates ink ejected from the inkjet head 100 with energy rays.
  • the pinning device 320 is arranged at the tip of the robot arm 310 on the front side of the head unit 224 (the “front side” in the inkjet head 100 described with reference to FIG. 3).
  • the pinning device 320 irradiates the ink with energy rays such as infrared light (especially, near-infrared light: wavelength of about 0.7 to 2.5 [ ⁇ m]), ultraviolet light (wavelength of about 10 to 400 [nm]), and excimer emission.
  • energy rays such as infrared light (especially, near-infrared light: wavelength of about 0.7 to 2.5 [ ⁇ m]), ultraviolet light (wavelength of about 10 to 400 [nm]), and excimer emission.
  • energy rays such as infrared light (especially, near-infrared light: wavelength of about 0.7 to 2.5 [ ⁇ m]), ultraviolet light (wavelength of about 10 to 400 [nm]), and excimer emission.
  • a pinning device 320 that emits near-infrared rays is exemplified.
  • the pinning device 320 includes a plurality of LEDs (light emitting diodes) 321 that emit near-infrared light, a light collecting plate 322 that collects the near-infrared light from each LED 321 at a predetermined irradiation position, and a light emitting circuit (not shown) of each LED 321. , which are integrally unitized by a housing and held at the tip of the robot arm 310 together with the head unit 224 .
  • LEDs light emitting diodes
  • FIG. 14 is a side view showing the relationship between the target position of ink ejection by the inkjet head 100 of the head unit 224 and the irradiation position of the near-infrared rays by the light collecting plate 322 of the pinning device 320.
  • FIG. This figure shows the state of the inkjet head 100 viewed from the left-right direction.
  • the appropriate ejection distance d from the nozzle surface of the inkjet head 100 to the target ejection position is determined to be a constant value based on the design conditions due to the principle restrictions of the ejection operation. .
  • ejection is performed with a target ejection position P set to a position that is the ejection distance d ahead of each nozzle 111 .
  • the light-condensing plate 322 of the pinning device 320 can irradiate a range that can include all the ejection positions P that are the ejection distance d forward from all the nozzles 111 of the plurality of inkjet heads 100 of the head unit 224 and their surroundings.
  • the irradiation direction and the light collection range are adjusted as follows.
  • an ultraviolet lamp or an ultraviolet LED is mounted as a light source, and when excimer light emission is emitted, an excimer lamp is mounted as a light source. Also in these cases, it is preferable to provide a condensing plate for condensing light onto the ejection positions P of all the nozzles 111 of the inkjet head 100 .
  • the pinning device 320 irradiates the energy beams so as to include the ejection positions P of the ink ejected from all the nozzles 111 of the head unit 224, so that the energy rays are ejected and attached to the surface of the work W, which is the object to be drawn.
  • the pinning device 320 is not limited to various energy beam irradiation devices, and may be a heating device that heats the ejected ink.
  • the heating device preferably includes a heater element serving as a heat source for heating the ink, and blowing means such as a fan for blowing high-temperature air heated by the heater element to the ink adhesion position.
  • blowing means such as a fan for blowing high-temperature air heated by the heater element to the ink adhesion position.
  • high-temperature air can be intensively applied to the ink adhering to the surface of the work W, and the ink can be effectively fixed by rapid drying.
  • the drawing apparatus 300 may be configured to include a distance measuring device 225 at the tip of the robot arm 310 together with the head unit 224 and the pinning device 320 .
  • the distance measurement device 225 is a detection device that detects the distance from each nozzle 111 of the head unit 224 to the surface of the workpiece W in front, for example, a two-dimensional or three-dimensional measurement device such as LiDAR (Laser Imaging Detection and Ranging). be.
  • LiDAR Laser Imaging Detection and Ranging
  • the robot arm 310 can be controlled so that the distance from each nozzle 111 to the front surface of the workpiece W is maintained at the above-described appropriate discharge distance d.
  • the distance measuring device 225 is not an essential component in the rendering device 300 .
  • each nozzle 111 outputs the workpiece W based on the surface position coordinates of the workpiece W.
  • the distance measuring device 225 can be made unnecessary by controlling the distance to the surface of the work W so as to maintain an appropriate ejection distance d.
  • the coordinates of the surface of the work W developed in the coordinate system of the robot arm 310 and the distance of the surface of the work W detected by the distance measuring device 225 are collated, and both are used to control the robot arm 310. good too.
  • the ink used in the inkjet head 100 is not particularly limited as long as it can be ejected from the inkjet head, but from the viewpoint of obtaining stable ejection characteristics, the viscosity (25° C.) at a shear rate of 1000 [1/s] should be 200 mPa ⁇ s or less. It is preferable that the ink has a thixotropic property. Furthermore, from the viewpoint of good injection properties, the viscosity at a shear rate of 1000 [1/s] is more preferably 2 to 100 mPa ⁇ s, and even more preferably 5 to 15 mPa ⁇ s.
  • the viscosity of the ink at a shear rate of 100 [1/s] is greater than the viscosity at a shear rate of 1000 [1/s], and the viscosity at a shear rate of 10 [1/s] is 100 [1/s]. It is preferable that the viscosity is greater than the viscosity at the time of s] because it has thixotropic properties, and the thixotropic properties increase the viscosity after ejection, thereby preventing liquid dripping.
  • the ink preferably contains an aqueous solvent (water-soluble solvent, water), a pigment and a fixing resin, and more preferably contains a thixotropic agent.
  • the ink contains a pigment in the range of 3 to 10% by mass, a fixing resin in the range of 8 to 20% by mass, and a water-soluble solvent in the range of 10 to 30% by mass, and It is preferable that water is contained within the range of 40 to 79% by mass.
  • the ink according to the present invention preferably has a solid content of 6 to 30% by mass.
  • “Ink solids” refers to solid components that cannot be removed from the ink by drying at 100°C.
  • the solid content of the ink is, for example, components other than the solvent including the aqueous solvent.
  • the ink may contain any component that does not impair the above-described properties relating to thixotropy, in addition to the aqueous solvent, pigment, fixing resin, and thixotropy-imparting agent.
  • optional components include pigment dispersants and surfactants. Each component in the thixotropic ink will be described below.
  • the thixotropy-imparting agent is not particularly limited as long as it is a material capable of imparting thixotropy that satisfies the conditions of the viscosity characteristics described above.
  • the thixotropy-imparting agent preferably has a particle shape (however, the particle shape includes a fiber shape), and more preferably has an aspect ratio of 20 or more.
  • the shape is preferably elliptical, scale-like, plate-like, needle-like, fiber-like, or the like.
  • the aspect ratio indicating the ratio of the major axis to the minor axis of the thixotropic agent is preferably 20 or more. When the aspect ratio is 20 or more, it is easier to impart thixotropy to the ink.
  • the long diameter of the thixotropy-imparting agent is preferably 2 ⁇ m or less. If the major axis of the thixotropy-imparting agent exceeds 2 ⁇ m, it may affect the ink-jet dischargeability.
  • the cross section for measuring the aspect ratio of the thixotropy-imparting agent is a cross section parallel to the length direction of the particle and cut in the thickness direction.
  • the aspect ratio is a value determined from the average major particle diameter and average minor diameter of 50 particles obtained from the cross section.
  • the short axis is the thickness of the particle
  • the long axis is the long side of the cross section perpendicular to the thickness direction of the particle, in other words, when the particle is viewed from above.
  • the major axis is the length of the particle
  • the minor axis is the major axis or maximum width of the cross section perpendicular to the length direction of the particle, in other words, when the particle is viewed from above. be.
  • Materials for the thixotropic agent include polysaccharides and inorganic particles.
  • polysaccharides include cellulose, chitin, chitosan, xanthan gum, welan gum, succinoglycan, guar gum, locust bean gum and derivatives thereof, glycomannan, agar, and carrageenan.
  • the derivatives include cellulose derivatives such as methyl cellulose, hydroxyethyl cellulose, and carboxymethyl cellulose.
  • polysaccharides natural polysaccharides with a weight average molecular weight of about several million are preferable. Specifically, xanthan gum, guar gum, carrageenan, and the like are preferred.
  • polysaccharides such as shells of crustaceans such as trees, crabs, and shrimps are subjected to oxidation treatment using a catalyst, mechanical treatment using a grinder, and the like.
  • Polysaccharide nanofibers are preferably used, which are finely pulverized by dissolving the fibers extremely finely.
  • the polysaccharide in the polysaccharide nanofiber is preferably at least one of cellulose, chitin and chitosan, and more preferably cellulose.
  • nanofibers refer to those having a width of about 1 to 100 nm and an aspect ratio of 100 or more.
  • the length and width of nanofibers can be measured, for example, using electron microscopy.
  • the width of the nanofiber may be measured, for example, as the width in plan view, or as the diameter of the cross section perpendicular to the longitudinal direction of the nanofiber.
  • the "width" of the nanofiber is the average of the maximum widths of each nanofiber in the 50 nanofibers.
  • the "length" of a nanofiber is the average length of 50 nanofibers.
  • the aspect ratio of a nanofiber is determined as the length divided by the width.
  • nanofibers with a smaller size are preferred.
  • the width of the nanofibers is preferably 1-50 nm, more preferably 1-5 nm.
  • the length of the nanofiber is preferably 0.5 to 2 ⁇ m, more preferably 0.5 to 1 ⁇ m, but is not limited thereto.
  • the aspect ratio of the nanofibers is more preferably in the range of 20-400, more preferably in the range of 100-300.
  • polysaccharides such as cellulose, chitin, and chitosan exist in a state in which structural units called microfibrils are bound together. These microfibrils have a width of 3 to 4 nm and a length of several ⁇ m (for example, 2 to 5 ⁇ m), but it is difficult to untie them one by one. In the case of mechanical crushing of polysaccharide aggregates, nanofibers with a width of about 20 to 50 nm are obtained in many conventional methods.
  • such nanofibers may be used as the polysaccharide nanofibers, but it is more preferable to use TEMPO-oxidized nanofibers that have been broken into finer, for example, microfibril units by TEMPO oxidation.
  • TEMPO oxidation is an oxidation reaction catalyzed by 2,2,6,6-tetramethyl-1-piperidine-oxy radical (TEMPO). Oxidation of polysaccharide aggregates in the presence of TEMPO yields extremely fine nanofibers corresponding to microfibrils, for example, 3-4 nm wide and several ⁇ m long (eg, 2-5 ⁇ m). .
  • the cellulose nanofiber used as a thixotropic agent is cellulose nanofiber.
  • Examples of forms of nanofiber cellulose include powdered cellulose and microcrystalline cellulose.
  • Cellulose nanofibers include Rheocrysta (registered trademark) manufactured by Daiichi Kogyo Seiyaku Co., Ltd., TEMPO oxidized cellulose nanofiber manufactured by Nippon Paper Industries Co., Ltd., Celenpia TC-01A, Celenpia TC-02X ("Celempia” is a registered trademark), and Sugino Machine.
  • IMa-10002, BMa-10002, WMa-10002, AMa-10002, FMa-10002 manufactured by Co., Ltd., ELEX- ⁇ , ELEX-S manufactured by Daio Paper Co., Ltd., Auro Visco manufactured by Oji Paper Co., etc. can be suitably used. .
  • the inorganic particles are not limited as long as they are particles having a material and a shape that can impart thixotropy to the ink that satisfies the conditions described above regarding thixotropy, but particles of various natural or synthetic clay minerals are preferable.
  • a smectite clay mineral is preferable as the clay mineral.
  • Smectite clay minerals are classified in the phyllosilicate class of layered silicate minerals or bentonite group minerals.
  • Smectite clay minerals are classified into the montmorillonite subgroup and the saponite subgroup according to their layered structure.
  • the montmorillonite subgroup includes montmorillonite, nontronite or beidellite.
  • the saponite subgroup includes hectorite, saponite or sauconite.
  • the smectite clay mineral may be either natural or synthetic.
  • a smectite clay mineral is a layered substance in which plate-like bodies are laminated, and when used as a thixotropy-imparting agent, it is usually used as plate-like particles separated between layers.
  • Synthetic smectite clay minerals have a smaller aspect ratio and less impurity content than natural ones.
  • the plate-like particles of the smectite clay mineral preferably have a thickness in the range of 0.2 to 3.0 nm and a length in the range of 10 to 150 nm. More preferably, the platelet-like particles have a thickness in the range of 0.2-2.0 nm and a length in the range of 10-125 nm.
  • the aspect ratio is a value obtained by dividing the length of the plate-like particles by the thickness, and is preferably 20 or more. More preferably, the aspect ratio is in the range of 20-200.
  • the length and thickness of plate-like particles can be measured, for example, using an electron microscope.
  • the thickness of the plate-like particles is, for example, the average value of 50 thicknesses of the plate-like particles measured on a given cross section.
  • the “length” of the plate-like particles is the average value of 50 lengths measured as the maximum diameter when the plate-like particles are viewed in plan.
  • the aspect ratio of plate-like particles is determined as a value obtained by dividing the length by the thickness.
  • Laponite manufactured by Big Chemie
  • Big Chemie which is a synthetic layered silicate
  • Laponite is a synthetic low charge clay that is close in structure and chemical composition to the natural smectite clay mineral hectorite.
  • the main particles of Laponite are disc-shaped with a maximum diameter of 30 nm and a thickness of 1 nm.
  • a commercially available product may be used as the smectite clay mineral.
  • Examples of commercially available products include Laponite RD (manufactured by Big Chemie), Kunipia F and Kunipia G, which are purified bentonites manufactured by Kunimie Kogyo Co., Ltd., and the like.
  • alumina nanofibers manufactured by Kawaken Fine Chemicals Co., Ltd. (with a short diameter of 4 nm and a long diameter of 1400 nm), which are nanofibers, may be used.
  • the content of the thixotropy-imparting agent in the ink according to the present embodiment is preferably in the range of 0.01 to 1% by mass with respect to the total amount of the ink, and is in the range of 0.08 to 0.5% by mass. It is more preferable to have
  • the thixotropy-imparting agents may be used singly or in combination of two or more.
  • the thixotropy-imparting agent is preferably composed of two or more materials.
  • one of the two or more materials is preferably a smectite clay mineral.
  • Preferred combinations of thixotropic agents include a combination of cellulose nanofibers and smectite clay minerals, and a combination of xanthan gum and smectite clay minerals. A combination of cellulose nanofibers and smectite clay minerals is particularly preferred.
  • Cellulose nanofibers and smectite clay minerals even when used alone, form a specific gel structure at an ink drying rate of 20%, for example, to impart elastic properties to the ink. It is considered possible. Moreover, by using a combination of cellulose nanofibers and smectite clay minerals, the above elastic properties are further enhanced, which is preferable.
  • the ratio of the smectite clay mineral and the other thixotropic agent can be selected according to the ink viscosity and the thixotropic property. It can be adjusted in a range of 10. By combining them, the thixotropy of the ink is greatly improved and the image quality is improved as compared with the addition of each of them alone. The reason why the thixotropy is improved is presumed, but it is conceivable that the smectite clay mineral has an electric charge, and the smectite clay mineral and other thixotropy-imparting agents are electrically associated to form a structure.
  • pigment Conventionally known organic and inorganic pigments can be used as the pigment contained in the ink according to the present invention.
  • the ink according to this embodiment optionally contains a pigment dispersant to disperse the pigment.
  • the pigment dispersant is not particularly limited, but a polymer dispersant having an anionic group is preferable, and one having a number average molecular weight within the range of 5,000 to 200,000 can be suitably used.
  • the ink according to this embodiment contains an aqueous solvent.
  • the aqueous solvent contains water as an essential solvent, and preferably optionally contains a known water-soluble solvent for viscosity adjustment and the like.
  • the ink according to this embodiment optionally contains a fixing resin.
  • the fixing resin functions as a binder for the pigment, which is the colorant, to improve the adhesion of the coating film to the object to be drawn, and to improve the abrasion resistance of the coating film obtained using the ink.
  • the fixing resin is preferably a water-insoluble resin.
  • the water-insoluble resin as the fixing resin is preferably used in the form of fine particles dispersed in an aqueous solvent.
  • the ink can optionally contain surfactants. As a result, it is possible to improve the ejection stability of the ink and to control the spread (dot diameter) of droplets that have landed on the object to be drawn.
  • Surfactants can be used without any particular limitation as long as they do not impair the effects of the present invention.
  • the above-described inks may contain, as necessary, in accordance with the purpose of improving emission stability, storage stability, image storage stability, and other various performances within a range that does not impair the effects of the present invention.
  • Various known additives such as viscosity modifiers, resistivity modifiers, film-forming agents, ultraviolet absorbers, antioxidants, anti-fading agents, anti-mold agents, anti-rust agents, etc. can be appropriately selected and used. .
  • the ink is prepared by mixing each of the above components so that the content is the above.
  • the pigment is dispersed in a portion of the aqueous solvent with a pigment dispersant and mixed with other components as a dispersion.
  • the fixing resin is preferably mixed with other components as a dispersion in a portion of the aqueous solvent using a surfactant added as necessary.
  • the ink may contain a gelling agent.
  • Ink containing a gelling agent is described in detail in paragraphs 0027 to 0055 of International Publication WO2021/001937A1, which can be applied.
  • the ink may contain an ultraviolet curing agent.
  • Ink containing an ultraviolet curing agent is described in detail in paragraphs 0067 to 0129 of JP-A-2020-172043, and this can be applied.
  • Ink containing an ultraviolet curing agent may further contain an ultraviolet absorber.
  • the ultraviolet absorber is not particularly limited, for example, those described in JP-A-57-74193, JP-A-57-87988 and JP-A-62-261476 can be applied.
  • FIG. 15 is a block diagram showing the main functional configuration of the rendering device 300.
  • the drawing device 300 includes the robot arm 310, the head unit 224, the pinning device 320, the ink circulation device 8, the distance measuring device 225, the temperature adjustment device 226, the control section 240, and the like, as described above.
  • the control unit 240 is connected to each of the above components that make up the drawing apparatus 300, and controls these components.
  • the control unit 240 has a CPU, RAM, ROM (not shown), and the like.
  • the CPU reads and executes various programs, data, and the like according to the content of processing from a storage device such as a ROM, and controls the operation of each unit of the rendering device 300 according to the content of the executed processing.
  • the RAM temporarily stores various programs and data processed by the CPU.
  • the ROM stores various programs, data, and the like read by the CPU and the like.
  • control unit 240 performs three-dimensional data prepared in advance defining the surface shape of the work W and the drawing range, or the detection of the distance measuring device 225 as basic control for executing drawing on the work W. Based on the obtained three-dimensional data of the surface shape of the workpiece W and the area to be drawn, motion control for drawing is executed in the area to be drawn. In other words, while ejecting ink from each nozzle 111 of the head unit 224 and irradiating near-infrared rays by the pinning device 320, the robot is moved so that the inkjet head 100 can be scanned forward or backward (conveyance of the head unit 224). Motion control of the arm 310 is executed. The scanning of the head unit 224 may be repeated while changing the position of the head unit 224 in the horizontal direction.
  • control unit 240 performs the following processing on the ink circulation device 8 of the drawing device 300 . That is, the control unit 240 controls the flow path R communicating with the nozzle 111 so that the average shear rate of the flow path R communicating with the nozzle 111 becomes a preset shear rate in the range of 1000 to 10000 [1/s].
  • the ink circulation amount is in the range of 30 to 300 [ml/min].
  • a liquid level sensor is provided to detect the liquid level of each of the sub-tanks 81 and 82, and the liquid levels of the tanks 81 and 82 are appropriately adjusted by operating the pumps 88 and 89 to achieve the target pressure P1 and pressure P2. of ink (circulation flow Q).
  • a reserve ink tank serving as a buffer may be provided in the middle of the ink flow path 86 .
  • the pressure P1 and the pressure P2 may be adjusted, and the circulation flow rate Q may be controlled by the pressure difference (circulation differential pressure ⁇ P) between the pressure P1 and the pressure P2.
  • the circulation differential pressure ⁇ P is preferably within the range of 5 kPa to 30 kPa.
  • control unit 240 performs temperature control of ink by the temperature adjustment device 226 as basic control for executing drawing on the work W.
  • the ink is temperature dependent, especially when it contains a gelling agent, a decrease in temperature causes an increase in viscosity due to gelation. For this reason, the control unit 240 heats the ink before it is ejected from the inkjet head 100 by the temperature adjustment device 226, creates a temperature difference between the ink and the surface of the work W, and attaches the ink to the surface of the work W. Control is performed to effectively gel the ink that has been applied.
  • the temperature adjustment device 226 controls the ink before being ejected from the inkjet head 100. is controlled to be heated to 80° C. to reduce the viscosity before ejection, and after ejection, the ink adhering to the surface of the work W is gelled to improve adhesion.
  • a means for detecting the temperature of the workpiece W may be provided in the chamber 330, and control may be performed to adjust the temperature of the ink by the temperature adjusting device 226 based on the detected temperature.
  • the control unit 240 also includes an attitude control unit 241, a distance control unit 242, a nozzle selection control unit 243, a nozzle selection control unit 243, a distance control unit 242, a nozzle selection control unit 243, and a control unit 241, which execute predetermined control for realizing more suitable drawing in addition to the basic control described above.
  • a drawing control unit 244 is provided.
  • the attitude control unit 241, the distance control unit 242, the nozzle selection control unit 243, and the first drawing control unit 244 are functional configurations realized by the CPU of the control unit 240 executing software. However, hardware such as a circuit for executing these functions may be provided together with the control unit 240 . Note that although FIG.
  • the attitude control section 241 controls the attitude of the head unit 224 . That is, the posture control unit 241 controls the operation of the robot arm 310 so that each inkjet head 100 of the head unit 224 ejects ink in a direction facing the surface of the work W (for example, perpendicularly). More specifically, as shown in FIG. 14, the ink ejected from the nozzle 111 located at the center position c (see FIG. 16) in the horizontal direction among all the nozzles 111 of the head unit 224 is applied to the surface of the work W.
  • the row direction of the nozzles 111 (the horizontal direction in the inkjet head 100) is oriented in the direction orthogonal to the scanning direction of the head unit 224 so that drawing is performed.
  • the robot arm 310 is controlled.
  • the scanning direction of the head unit 224 is determined by the surface shape of the workpiece W, for example. For example, if the surface shape is flat, scanning is performed in an arbitrary direction along the flat surface, and if the surface shape is like a ridge, scanning is performed along the ridge. At this time, the inclination of the surface of the workpiece W on the scanning line of the head unit 224 can be obtained from the above-described three-dimensional data or detection by the distance measuring device 225 .
  • the distance control section 242 executes scanning control of the head unit 224 which is executed together with attitude control of the head unit 224 by the attitude control section 241 . That is, the distance control unit 242 adjusts the robot arm 310 so that the scanning of the head unit 224 is performed while the distance from the nozzle 111 at the center position c to the surface of the workpiece W is maintained at the proper discharge distance d. Perform motion control. More specifically, as shown in FIG. 14, the distance from the tip of the nozzle 111 located at the aforementioned center position c (see FIG. 16) to the surface of the workpiece W on the extension line in the ejection direction maintains the ejection distance d.
  • the robot arm 310 is controlled so that the head unit 224 is transported in the scanning direction.
  • the distance to the surface of the workpiece W on the scanning line of the head unit 224 can be obtained from the three-dimensional data described above or from the detection of the distance measuring device 225 .
  • the nozzle selection control section 243 executes ejection control of the inkjet head 100 executed together with the attitude control section 241 and the distance control section 242 . That is, the nozzle selection control unit 243 performs operation control for each inkjet head 100 to restrict ejection of the nozzles 111 whose distance to the workpiece W is outside the proper ejection distance d (target value).
  • FIG. 16A and 16B are explanatory diagrams of ejection control of the inkjet head 100 by the nozzle selection control unit 243.
  • FIG. As described above, the distance from the nozzle 111 at the center position c to the surface of the workpiece W is maintained at the appropriate ejection distance d by scanning control by the distance control unit 242, and drawing is performed. Other nozzles 111 that eject ink may not be able to maintain a proper ejection distance d depending on the surface shape of the work W.
  • FIG. For example, if the range of the distance allowed as the proper ejection distance from the nozzle 111 to the surface of the workpiece W is within a range of ⁇ d with respect to d, the nozzle selection control unit 243 arranges the ink in a line.
  • the distance to the surface of the work W is obtained for all nozzles 111 that eject ink, and the nozzles 111 whose distance is outside the range of ⁇ d with respect to d are controlled to prohibit ink ejection.
  • the solid line arrow indicates the discharge permitted state
  • the dotted line indicates the discharge prohibited state.
  • the nozzle selection control unit 243 may select nozzles as follows.
  • Control is performed to prohibit ejection from all nozzles 111 whose distance to the surface of the workpiece W is outside the range of ⁇ d with respect to d, and which are farther than the nozzle 111 closest to the nozzle 111 at the center position c. you can go
  • the first drawing control unit 244 scans the head unit 224 from the rear side of the head unit 224 when the pinning device 320 sets the traveling direction of the head unit 224 to the front. Control the robot arm 310 to maintain the ink thickening configuration. For example, as shown in FIG. 2, when the head unit 224 is scanned in the M direction (to the left in the drawing), the pinning device 320 is kept on the right side of the head unit 224 (rear side in the traveling direction). is done.
  • the near-infrared rays can be irradiated so as to follow the ink adhering to the surface of the work W, effectively increasing the viscosity of the ink after ejection. be able to.
  • the drawing apparatus 300 configured as described above performs drawing while the robot arm 310 holds the inkjet head 100 . Since the inkjet head 100 ejects ink droplets from individual nozzles 111, unlike the case of spraying paint, the ink droplets are attached one by one to the surface of the work W, which is the object to be drawn. This makes it possible to perform drawing with little loss. In addition, since the ink is less likely to scatter, it is possible to appropriately draw with ink at the target position and range, and it is possible to reduce the burden of advance preparation such as masking. In addition, it is possible to reduce the burden of post-processing of excess ink that is scattered.
  • the drawing device 300 includes the pinning device 320 that increases the viscosity of the ink ejected from the inkjet head 100, even if the surface of the work W is inclined or downward rather than horizontal, Also, it is possible to effectively reduce the dripping of the adhered ink, and it is possible to improve the drawing quality.
  • the pinning device 320 of the drawing device 300 performs pinning so as to increase the viscosity of the ink ejected from the inkjet head 100 on the surface of the work W. is suppressed.
  • the pinning device 320 is held by the robot arm 310 together with the inkjet head 100, it is possible to maintain a constant relationship between the ink adhesion position and the position at which the pinning device 320 pins the ink. Regardless of the operation of 310, it is possible to stably perform drawing with little dripping.
  • control unit 240 includes the attitude control unit 241
  • the ink is properly ejected from the inkjet head 100 in a direction perpendicular to the surface of the work W, so that better drawing can be performed. It is possible to maintain the drawing quality even higher.
  • the nozzle 111 can be directed in an appropriate direction to face the work W, and the nozzle 111 can be satisfactorily applied to any inclined plane. It is possible to draw.
  • control unit 240 of the drawing apparatus 300 includes the distance control unit 242, drawing can be performed while maintaining an appropriate discharge distance d with respect to the surface of the work W, and high drawing quality can be maintained. becomes possible.
  • control unit 240 since the control unit 240 includes the nozzle selection control unit 243, ejection from the nozzles 111 that deviate from the appropriate ejection distance d due to unevenness or curved shape of the surface of the work W is restricted. High drawing quality can be maintained regardless of the surface shape.
  • control unit 240 includes the first drawing control unit 244, when drawing is performed by scanning the inkjet head 100 in a predetermined scanning direction, even if the course in the scanning direction changes,
  • the pinning device 320 can perform pinning so as to follow the ink adhering to the surface of the work W, and it is possible to effectively increase the viscosity of the ink after ejection.
  • the pinning device 320 is an irradiation device that irradiates the ejected ink with energy rays such as infrared rays, ultraviolet rays, or excimer emission, it is possible to effectively dry or cure the ejected ink. Ink adheres better and dripping can be suppressed more effectively.
  • energy rays such as infrared rays, ultraviolet rays, or excimer emission
  • the pinning device 320 is composed of a heating device that heats the ejected ink, the ejected ink can be dried effectively, and the ink adheres more effectively and the liquid is more effectively dried. Who can be restrained? Moreover, when a heating device is used as the pinning device, it is possible to achieve necessary and sufficient pinning because the amount of heat can be easily adjusted.
  • the drawing apparatus 300 ejects thixotropic ink having a viscosity of 200 [mPa s] or less at a shear rate of 1000 [1/s] by the inkjet head 100, the ink is sheared before ejection. If the speed is increased, the viscosity is reduced, enabling good discharge. It becomes possible to suppress dripping more effectively.
  • the drawing apparatus 300 includes the ink circulation device 8 that circulates the ink supplied to the nozzles 111 at a shear rate of 1000 [1/s] or higher, the viscosity of the thixotropic ink can be sufficiently reduced. It can be supplied to the nozzles 111 of the inkjet head 100, and good ejection can be performed.
  • the ink circulation device 8 circulates the ink at an ink circulation rate of 30 [ml/min] or more, thereby enabling the circulation of the ink at a high shear rate, and the thixotropic ink can be discharged more satisfactorily. becomes possible.
  • the pinning device 320 can be configured to irradiate the ink with ultraviolet rays so that the ink adhered to the surface of the work W can be cured. It becomes possible to reduce the dripping of the liquid more effectively. Furthermore, when an ultraviolet absorber is added to the ink, the curability of the ultraviolet curing agent is improved, and dripping of the ink can be reduced more effectively. Furthermore, when a gelling agent is added to the ink, the ink can be gelled due to its temperature dependence, so that it is possible to more effectively reduce ink dripping.
  • the drawing apparatus 300 since the drawing apparatus 300 includes the temperature adjustment device 226 that heats the ink before it is ejected from the inkjet head 100, it is possible to eject the ink at an appropriate temperature according to the temperature dependency of the ink. becomes.
  • the temperature adjustment device 226 heats the ink to a temperature at which it melts, and by creating a temperature difference from the surface temperature of the work W in advance, the ink is discharged. The subsequent ink can be satisfactorily gelled on the surface of the work W, and ink dripping can be reduced more effectively.
  • FIG. 17 is a front view of a drawing apparatus 300 to which another configuration (1) of the head unit and pinning device is applied.
  • one head unit 224 and two pinning devices 320A and 320B are mounted on the tip of the robot arm 310.
  • Both of the pinning devices 320A and 320B have the same configuration as the pinning device 320 described above.
  • one pinning device 320A is arranged behind the head unit 224
  • the other pinning device 320B is arranged in front of the head unit 224.
  • the terms “front side” and “rear side” here refer to the "front side” and “rear side” of the inkjet head 100 described with reference to FIG.
  • the control unit 240 includes a second rendering control unit 245 in place of the first rendering control unit 244 described above (see FIG. 15).
  • the second drawing control unit 245 is also a functional configuration realized by the CPU of the control unit 240 executing software.
  • hardware such as a circuit that executes the functions of the second drawing control unit 245 may be provided together with the control unit 240 .
  • the second drawing control unit 245 sets the pinning device 320A to the rear side of the head unit 224 (the moving direction of the head unit 224 is the front side).
  • the robot arm 310 and the pinning device 320A are controlled so that the ink ejected onto the surface of the work W from the rear side of the head unit 224 is irradiated with near-infrared rays to perform the pinning operation.
  • the second drawing control unit 245 controls that when the head unit 224 scans the rear side MB of the inkjet head 100 to perform drawing, the pinning device 320B is positioned on the front side of the head unit 224 (the moving direction of the head unit 224 is The robot arm 310 and the pinning device 320B are controlled so that near-infrared rays are applied to the ink ejected onto the surface of the work W from the rear side of the head unit 224 (in the case of the front side) to perform the pinning operation.
  • the drawing apparatus 300 is equipped with another configuration (1) including the head unit and the pinning device, and scanning control is performed by the second drawing control unit 245, whereby forward scanning and backward scanning are performed. is continuously performed, it is possible to perform drawing smoothly and continuously while effectively suppressing the occurrence of dripping without changing the arrangement of the head unit 224 and the pinning devices 320A and 320B.
  • FIG. 18 is a front view of a drawing apparatus 300 to which another configuration (2) of the head unit and pinning device is applied.
  • two head units 224A and 224B and one pinning device 320 are mounted on the tip of a robot arm 310.
  • Both of the head units 224A and 224B have the same configuration as the head unit 224 described above.
  • one head unit 224 A is arranged on the front side with respect to the pinning device 320 and the other head unit 224 B is arranged on the rear side with respect to the pinning device 320 .
  • the terms “front side” and “rear side” refer to the “front side” and the “rear side” of the inkjet head 100 described with reference to FIG. It is assumed that the two head units 224A and 224B are attached to the tip of the robot arm 310 with the front, rear, left, right, and up and down directions aligned. The directions of the arrows indicating front, rear, top and bottom shown in FIG.
  • the control unit 240 includes a third rendering control unit 246 in place of the first rendering control unit 244 described above (see FIG. 15).
  • the third drawing control unit 246 is also a functional configuration realized by the CPU of the control unit 240 executing software.
  • hardware such as a circuit that executes the functions of the third drawing control unit 246 may be provided together with the control unit 240 .
  • the third drawing control unit 246 controls the front side with respect to the pinning device 320 (the pinning device The drawing device 300 is controlled so that ink is ejected from the head unit 224A located on the front side of 320) and the pinning device 320 irradiates the ink ejected onto the surface of the work W with near-infrared rays to perform a pinning operation. Further, when performing drawing by scanning the head unit 224 to the rear MB of the inkjet head 100, the third drawing control unit 246 controls the rear side of the pinning device 320 (the moving direction of the head unit 224 is the front side).
  • Ink is ejected from the head unit 224B located on the front side of the pinning device 320, and the pinning device 320 irradiates the ink ejected onto the surface of the work W with near-infrared rays to perform a pinning operation. to control.
  • the drawing apparatus 300 is equipped with the other configuration (2) including the head unit and the pinning device, and the scanning control is performed by the third drawing control unit 246, whereby forward scanning and backward scanning are performed. is continuously performed, it is possible to perform drawing smoothly and continuously while effectively suppressing the occurrence of dripping without changing the arrangement of the head units 224A and 224B and the pinning device 320.
  • the drawing apparatus 300 may be configured to include an adjustment mechanism 340 that adjusts the tilt angle of the work W.
  • FIG. 19 is a perspective view of the adjustment mechanism 340.
  • the adjustment mechanism 340 includes a base 341 and a support portion 342 that supports the workpiece W.
  • the base 341 supports the support portion 342 so as to be rotatable about a predetermined rotation axis J. As shown in FIG. In the example of FIG. 19, the base 341 supports the support portion 342 around the horizontal rotation axis J.
  • the work W when the work W is large, it may be configured to have two sets of the base 341 and the support portion 342 so that the work W is supported at both ends.
  • the angle of the work W is adjusted by the adjustment mechanism 340.
  • the control unit 240 may automatically perform a process of recalculating the coordinate values of the surface of the work W when the adjustment angle is input.
  • a sensor for detecting the rotation angle may be provided on the shaft of the support portion 342 of the adjustment mechanism 340, and a function of recalculating the coordinate values of the surface of the workpiece W in the coordinate system of the robot arm 310 from the detection signal may be provided.
  • the drawing device 300 paints the surface of the work W with a single color. good.
  • the head unit 224 may be detachable from the robot arm 310 and may be replaceable with another head unit 224 that draws various colors.
  • the single head unit 224 is provided with inkjet heads 100 for various colors (for example, Y (yellow), M (magenta), C (cyan), and K (black)), or The head unit 224 may be held by one robot arm 310, and drawing may be performed by multicolor image formation.
  • a multi-joint type robot arm 310 has been exemplified, the type of robot is not limited to this, and other types of robot configuration (for example, Cartesian coordinate type, SCARA type, etc.) may be partially or wholly incorporated. It's okay.
  • the present invention has industrial applicability for a drawing apparatus and drawing method that perform drawing by ejecting ink.
  • ink circulation device 100 inkjet head 111 nozzles 224, 224A, 224B head unit 225 distance measuring device 226 temperature adjustment device (temperature adjustment section) 240 control unit 241 attitude control unit 242 distance control unit 243 nozzle selection control unit 244 first drawing control unit 245 second drawing control unit 246 third drawing control unit 300 drawing device 310 robot arms 320, 320A, 320B pinning device 340 adjustment mechanism P discharge position W work (object to be drawn) d Discharge distance

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Abstract

In order to perform fine rendering while suppressing liquid dripping, a rendering device 300 is provided with an inkjet head 100, a robot arm 310 that holds the inkjet head 100, and a pinning device 320 that thickens ink ejected from the inkjet head 100. The pinning device 320 may perform heating of the ejected ink or irradiation of energy rays. The ink of the inkjet head 100 may have thixotropy. Further, the ink may contain an ultraviolet curing agent, an ultraviolet absorbing agent, or a gelling agent.

Description

描画装置及び描画方法Rendering device and rendering method
　本発明は、インクの吐出により描画を行う描画装置及び描画方法に関する。 The present invention relates to a drawing apparatus and a drawing method for drawing by ejecting ink.
　近年、立体等の対象物に着色、描画等を行うために、インクジェットヘッドを搭載した多軸ロボットアームが活用されている（例えば、特許文献１参照）。
　多軸ロボットアームは、対象物の表面に対してインクジェットヘッドを効果的に位置決めすることができ、インクジェットヘッドは、対象物に付着しないで飛散するミストの発生を抑えることができるなどの利点がある。 2. Description of the Related Art In recent years, a multi-axis robot arm equipped with an inkjet head has been utilized for coloring, drawing, etc. on a three-dimensional object (see, for example, Patent Document 1).
The multi-axis robot arm can effectively position the inkjet head on the surface of the object, and the inkjet head has the advantage of suppressing the generation of mist that scatters without adhering to the object. .
特開２０１６－１７５０７７号公報JP 2016-175077 A
　上記従来技術は、比較的水平な面に対しては良好な着色、描画を行うことができるが、対象となる面の傾きによってはインクの液だれが生じる恐れがあった。 Although the conventional technology described above can perform good coloring and drawing on a relatively horizontal surface, there is a risk of ink dripping depending on the inclination of the target surface.
　本発明の課題は、良好な描画を可能とする描画装置及び描画方法を提供することにある。 An object of the present invention is to provide a drawing apparatus and drawing method that enable good drawing.
　上記課題を解決するために、請求項１記載の発明は、描画装置において、
　インクジェットヘッドと、
　前記インクジェットヘッドを保持するロボットアームと、
　前記インクジェットヘッドから吐出されたインクを増粘させるピニング装置と、
　を備えることを特徴とする。 In order to solve the above problems, the invention according to claim 1 provides a drawing apparatus,
inkjet head,
a robot arm that holds the inkjet head;
a pinning device that thickens the ink ejected from the inkjet head;
characterized by comprising
　請求項２記載の発明は、請求項１に記載の描画装置において、
　前記ピニング装置は、前記インクジェットヘッドから吐出後のインクを被描画体の表面上で増粘させることを特徴とする。 The invention according to claim 2 is the drawing apparatus according to claim 1,
The pinning device is characterized by increasing the viscosity of the ink ejected from the inkjet head on the surface of the object to be drawn.
　請求項３記載の発明は、請求項１又は請求項２に記載の描画装置において、
　前記ピニング装置は、前記インクジェットヘッドと共に前記ロボットアームに保持されていることを特徴とする。 The invention according to claim 3 is the drawing apparatus according to claim 1 or claim 2,
The pinning device is held by the robot arm together with the inkjet head.
　請求項４記載の発明は、請求項１から請求項３のいずれか一項に記載の描画装置において、
　前記インクジェットヘッドのノズルから被描画体までの距離が目標値となるように前記ロボットアームを制御する距離制御部を備えることを特徴とする。 The invention according to claim 4 is the drawing apparatus according to any one of claims 1 to 3,
It is characterized by comprising a distance control unit for controlling the robot arm so that the distance from the nozzle of the inkjet head to the object to be drawn becomes a target value.
　請求項５記載の発明は、請求項１から請求項４のいずれか一項に記載の描画装置において、
　前記インクジェットヘッドは、並んで設けられた複数のノズルを有し、
　被描画体までの距離が目標値から外れるノズルの吐出を規制するノズル選択制御部を備えることを特徴とする。 The invention according to claim 5 is the drawing apparatus according to any one of claims 1 to 4,
The inkjet head has a plurality of nozzles arranged side by side,
It is characterized by comprising a nozzle selection control section that regulates ejection of nozzles whose distance to the object to be drawn deviates from a target value.
　請求項６記載の発明は、請求項１から請求項５のいずれか一項に記載の描画装置において、
　被描画体の表面に対向する向きで前記インクジェットヘッドがインクを吐出するように前記ロボットアームを制御する姿勢制御部を備えることを特徴とする。 The invention according to claim 6 is the drawing apparatus according to any one of claims 1 to 5,
It is characterized by comprising an attitude control section for controlling the robot arm so that the inkjet head ejects ink in a direction facing the surface of the object to be drawn.
　請求項７記載の発明は、請求項１から請求項６のいずれか一項に記載の描画装置において、
　被描画体の傾斜角度を調整する調整機構を備えることを特徴とする。 The invention according to claim 7 is the drawing apparatus according to any one of claims 1 to 6,
It is characterized by comprising an adjusting mechanism for adjusting the tilt angle of the object to be drawn.
　請求項８記載の発明は、請求項１から請求項７のいずれか一項に記載の描画装置において、
　前記ピニング装置は、吐出された前記インクにエネルギー線照射を行う照射装置であることを特徴とする。 The invention according to claim 8 is the drawing apparatus according to any one of claims 1 to 7,
The pinning device is an irradiation device that irradiates the ejected ink with an energy beam.
　請求項９記載の発明は、請求項８に記載の描画装置において、
　前記ピニング装置は、吐出された前記インクに赤外線、紫外線、エキシマ発光のいずれかのエネルギー線照射を行う照射装置であることを特徴とする。 The invention according to claim 9 is the drawing apparatus according to claim 8,
The pinning device is an irradiation device that irradiates the ejected ink with energy rays of infrared rays, ultraviolet rays, or excimer emission.
　請求項１０記載の発明は、請求項１から請求項７のいずれか一項に記載の描画装置において、
　前記ピニング装置は、吐出された前記インクを加熱する加熱装置であることを特徴とする。 The invention according to claim 10 is the drawing apparatus according to any one of claims 1 to 7,
The pinning device is a heating device that heats the ejected ink.
　請求項１１記載の発明は、請求項１から請求項１０のいずれか一項に記載の描画装置において、
　前記インクジェットヘッドから吐出される前の前記インクの温度を調整する温度調整部を備えることを特徴とする。 The invention according to claim 11 is the drawing apparatus according to any one of claims 1 to 10,
It is characterized by comprising a temperature adjusting section that adjusts the temperature of the ink before it is ejected from the inkjet head.
　請求項１２記載の発明は、請求項１から請求項１１のいずれか一項に記載の描画装置において、
　前記インクは、紫外線硬化剤、紫外線吸収剤又はゲル化剤の少なくとも一つを含有することを特徴とする。 The invention according to claim 12 is the drawing apparatus according to any one of claims 1 to 11,
The ink is characterized by containing at least one of an ultraviolet curing agent, an ultraviolet absorber and a gelling agent.
　請求項１３記載の発明は、請求項１から請求項１２のいずれか一項に記載の描画装置において、
　前記インクは、せん断速度1000[1/s]での粘度が200[mPa・s]以下となるチキソ性を有することを特徴とする。 The invention according to claim 13 is the drawing apparatus according to any one of claims 1 to 12,
The ink is characterized by having thixotropic properties such that the viscosity is 200 [mPa·s] or less at a shear rate of 1000 [1/s].
　請求項１４記載の発明は、請求項１３に記載の描画装置において、
　前記インクジェットヘッドのノズルに供給される前記インクをせん断速度1000[1/s]以
上で循環させる循環構造を備えることを特徴とする。 The invention according to claim 14 is the drawing apparatus according to claim 13,
It is characterized by comprising a circulation structure that circulates the ink supplied to the nozzles of the inkjet head at a shear rate of 1000 [1/s] or more.
　請求項１５記載の発明は、請求項１４に記載の描画装置において、
　前記循環構造のインク循環量が30[ml/min]以上であることを特徴とする。 The invention according to claim 15 is the drawing apparatus according to claim 14,
The ink circulation amount of the circulation structure is 30 [ml/min] or more.
　請求項１６記載の発明は、請求項１から請求項１５のいずれか一項に記載の描画装置において、
　前記ロボットアームは、前記インクジェットヘッドと前記ピニング装置とを共に保持し、
　前記インクジェットヘッドを所定の走査方向に走査して描画を行う際に、前記ピニング装置が前記インクジェットヘッドの進行方向に対して当該インクジェットヘッドの後側からインクを増粘させる制御を行う第一描画制御部を備えることを特徴とする。 The invention according to claim 16 is the drawing apparatus according to any one of claims 1 to 15,
The robot arm holds the inkjet head and the pinning device together,
When drawing is performed by scanning the inkjet head in a predetermined scanning direction, the pinning device performs control to increase the viscosity of the ink from the rear side of the inkjet head with respect to the traveling direction of the inkjet head. First drawing control A part is provided.
　請求項１７記載の発明は、請求項１から請求項１５のいずれか一項に記載の描画装置において、
　前記ロボットアームは、二つの前記ピニング装置を前記インクジェットヘッドの両側に保持し、
　前記インクジェットヘッドを所定の走査方向に平行な一方の方向に走査して描画を行う際に、前記インクジェットヘッドの前記一方の方向の進行方向に対して当該インクジェットヘッドの後側となる前記ピニング装置からインクを増粘させ、
　前記インクジェットヘッドを前記走査方向に平行な前記一方の方向とは逆方向に走査して描画を行う際に、前記インクジェットヘッドの前記逆方向の進行方向に対して当該インクジェットヘッドの後側となる前記ピニング装置からインクを増粘させるように制御を行う第二描画制御部を備えることを特徴とする。 The invention according to claim 17 is the drawing apparatus according to any one of claims 1 to 15,
the robot arm holds two pinning devices on opposite sides of the inkjet head;
When drawing is performed by scanning the inkjet head in one direction parallel to a predetermined scanning direction, from the pinning device behind the inkjet head with respect to the traveling direction of the inkjet head in the one direction thicken the ink,
When drawing is performed by scanning the inkjet head in a direction opposite to the one direction parallel to the scanning direction, the ink jet head located behind the inkjet head with respect to the traveling direction of the inkjet head in the opposite direction. It is characterized by comprising a second drawing control section that controls to increase the viscosity of the ink from the pinning device.
　請求項１８記載の発明は、請求項１から請求項１５のいずれか一項に記載の描画装置において、
　前記ロボットアームは、二つの前記インクジェットヘッドを前記ピニング装置の両側に保持し、
　前記インクジェットヘッドを所定の走査方向に平行な一方の方向に走査して描画を行う際に、前記インクジェットヘッドの前記一方の方向の進行方向に対して前記ピニング装置の前側となる前記インクジェットヘッドからインクを吐出させ、
　前記インクジェットヘッドを前記走査方向に平行な前記一方の方向とは逆方向に走査して描画を行う際に、前記インクジェットヘッドの前記逆方向の進行方向に対して前記ピニング装置の前側となる前記インクジェットヘッドからインクを吐出させるように制御を行う第三描画制御部を備えることを特徴とする。 The invention according to claim 18 is the drawing apparatus according to any one of claims 1 to 15,
The robot arm holds the two inkjet heads on both sides of the pinning device,
When drawing is performed by scanning the inkjet head in one direction parallel to a predetermined scanning direction, the ink is ejected from the inkjet head located in front of the pinning device with respect to the traveling direction of the inkjet head in the one direction. and
When drawing is performed by scanning the inkjet head in a direction opposite to the one direction parallel to the scanning direction, the inkjet head is on the front side of the pinning device with respect to the traveling direction of the inkjet head in the opposite direction. It is characterized by comprising a third drawing control unit that controls to eject ink from the head.
　請求項１９記載の発明は、描画方法において、
　請求項１に記載の描画装置を用いて描画を行うことを特徴とする。 According to the nineteenth aspect of the invention, in the drawing method,
Drawing is performed using the drawing apparatus according to claim 1.
　請求項２０記載の発明は、請求項１９に記載の描画方法において、
　前記インクはゲル化剤を含み、
　前記インクジェットヘッドから吐出される前のインクと被描画体との間に温度差を設け、前記被描画体に付着するインクのゲル化を促すことを特徴とする。 The invention according to claim 20 is the drawing method according to claim 19,
the ink comprises a gelling agent;
A temperature difference is provided between the ink before it is ejected from the inkjet head and the object to be drawn, and gelling of the ink adhering to the object to be drawn is promoted.
　本発明は、上記構成により、液だれの発生を抑制し、良好な描画を行うことが可能となる。 With the above configuration, the present invention can suppress the occurrence of dripping and perform good drawing.
本発明の実施の形態である描画装置の全体構成を示す側面図1 is a side view showing the overall configuration of a drawing apparatus that is an embodiment of the present invention; 描画装置の正面図Front view of drawing device ヘッドユニットの底面図Bottom view of head unit インクジェットヘッドの斜視図Perspective view of inkjet head インクジェットヘッドの断面図Cross-sectional view of an inkjet head インクジェットヘッドの分解斜視図Disassembled perspective view of inkjet head ヘッドチップの分解斜視図Disassembled perspective view of head chip 圧力室基板の平面図Top view of pressure chamber substrate 圧力室基板の底面図Bottom view of the pressure chamber substrate 流路スペーサー基板の平面図Plan view of channel spacer substrate 流路スペーサー基板の底面図Bottom view of channel spacer substrate ノズル基板の平面図Plan view of nozzle substrate IXA-IXAで切断したときのヘッドチップの断面図Cross-sectional view of the head chip when cut with IXA-IXA IXB-IXBで切断したときのヘッドチップの断面図Cross-sectional view of the head chip when cut with IXB-IXB XA-XAで切断したときのヘッドチップの断面図Cross-sectional view of the head chip when cut with XA-XA XB-XBで切断したときのヘッドチップの断面図Cross-sectional view of the head chip when cut with XB-XB インク循環系を示す模式図Schematic diagram showing ink circulation system ピニング装置の斜視図Perspective view of the pinning device インクジェットヘッドによるインク吐出の目標位置とピニング装置の近赤外線の照射位置との関係を示す側面図FIG. 4 is a side view showing the relationship between the target position of ink ejection by the inkjet head and the near-infrared irradiation position of the pinning device; 描画装置の主要な機能構成を示すブロック図Block diagram showing the main functional configuration of the drawing device ノズル選択制御部によるインクジェットヘッドの吐出制御の説明図Explanatory drawing of the ejection control of the inkjet head by the nozzle selection control unit. ヘッドユニット及びピニング装置の他の構成(1)を適用した描画装置の正面図Front view of a drawing device to which another configuration (1) of the head unit and pinning device is applied ヘッドユニット及びピニング装置の他の構成(2)を適用した描画装置の正面図Front view of a drawing device to which another configuration (2) of the head unit and pinning device is applied 調整機構の斜視図Perspective view of adjustment mechanism
［発明の実施形態の概略］
　以下、図面を参照しながら、本発明の好ましい実施形態について説明する。ただし、発明の範囲は図示例に限定されない。
　図１は本発明の実施の形態である描画装置３００の全体構成を示す側面図、図２は正面図である（但し、図２は後述するヘッドユニット２２４が下向きの状態）。 [Overview of Embodiments of the Invention]
Preferred embodiments of the present invention will be described below with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.
1 is a side view showing the overall configuration of a drawing apparatus 300 according to an embodiment of the present invention, and FIG. 2 is a front view (however, FIG. 2 shows a state in which a head unit 224, which will be described later, faces downward).
　描画装置３００は、複数のインクジェットヘッド１００を有するヘッドユニット２２４と、当該ヘッドユニット２２４を保持するロボットアーム３１０と、インクジェットヘッド１００から吐出されたインクを増粘させるピニング装置３２０と、これらの各構成及び被描画体としてのワークＷ（図１４，図１６参照）を格納するチャンバー３３０と、上記各構成の動作制御を行う制御部２４０とを主に備えている。 The drawing apparatus 300 includes a head unit 224 having a plurality of inkjet heads 100, a robot arm 310 that holds the head unit 224, a pinning device 320 that thickens the ink ejected from the inkjet heads 100, and each of these components. and a chamber 330 for storing a workpiece W (see FIGS. 14 and 16) as an object to be patterned, and a controller 240 for controlling the operation of each of the components described above.
［ロボットアーム］
　ロボットアーム３１０は、土台となるベース３１１と、関節３１３で連結された複数のアーム３１２と、各関節ごとに設けられた駆動源としてのサーボモーターと、各サーボモーターにより回転又は回動されるアーム角度をそれぞれ検出するエンコーダーとを備える垂直多関節型のロボットアームであり、関節３１３で連結された複数のアーム３１２の先端部にはインクジェットヘッド１００及びピニング装置３２０が保持されている。 [Robot arm]
The robot arm 310 includes a base 311 as a base, a plurality of arms 312 connected by joints 313, servo motors as drive sources provided for each joint, and arms rotated or rotated by each servo motor. It is a vertically articulated robot arm equipped with encoders for detecting angles, and an inkjet head 100 and a pinning device 320 are held at the tips of a plurality of arms 312 connected by joints 313 .
　上記各関節３１３は、アーム３１２の一端部を揺動可能として他端部を軸支する揺動関節と、アーム３１２自身をその長手方向を中心に回転可能に軸支する回転関節とのいずれかから構成される。
　そして、ロボットアーム３１０は、六つの関節３１３を具備しており、六軸によってその先端部のインクジェットヘッド１００及びピニング装置３２０を任意の位置に位置決めし、任意の姿勢をとらせることができる。
　従って、ロボットアーム３１０は、ワークＷの表面の立体的な曲面上の任意の曲線に沿ってヘッドユニット２２４を走査して描画を行わせることが可能である。
　なお、本実施形態において、「走査」とは、ヘッドユニット２２４を移動させながら描画を行うことをいう。 Each of the joints 313 is either a rocking joint that pivotally supports one end of the arm 312 and pivots the other end, or a rotary joint that pivotally supports the arm 312 itself so that it can rotate about its longitudinal direction. consists of
The robot arm 310 has six joints 313, and can position the inkjet head 100 and the pinning device 320 at the tip of the arm 310 at arbitrary positions and take arbitrary postures.
Therefore, the robot arm 310 can scan the head unit 224 along an arbitrary curved line on the three-dimensional curved surface of the work W to perform drawing.
In the present embodiment, “scanning” means drawing while moving the head unit 224 .
　なお、ロボットアーム３１０は、六軸に限らず、七つの関節を有する七軸のものを採用してもよい。その場合、冗長関節が生じるので、インクジェットヘッド１００及びピニング装置３２０を任意の位置に位置決めし、任意の姿勢をとらせながら、途中の関節を移動させることができるようになるので、ロボットアーム３１０の周囲の他の物体との干渉を回避することができる。従って、インクジェットヘッド１００及びピニング装置３２０をより広い範囲で任意の位置に位置決めし、任意の姿勢をとらせることができる。 It should be noted that the robot arm 310 is not limited to 6-axis, and a 7-axis arm having 7 joints may be adopted. In that case, since redundant joints are generated, the inkjet head 100 and the pinning device 320 can be positioned at arbitrary positions, and the intermediate joints can be moved while taking arbitrary postures. Interference with other surrounding objects can be avoided. Therefore, the inkjet head 100 and the pinning device 320 can be positioned at arbitrary positions in a wider range and can be made to assume arbitrary postures.
［チャンバー］
　チャンバー３３０は、ロボットアーム３１０及びワークＷを密閉状態で格納する格納室である。チャンバー３３０の内部には、ワークＷを載置する作業台３３１が設けられている。作業台３３１には、ワークＷを所定の姿勢に保持する治具を設けてもよい。
　また、チャンバー３３０内は、外気を遮断し、防塵、防湿を図ることができる。 [Chamber]
The chamber 330 is a storage room that stores the robot arm 310 and the workpiece W in a sealed state. A workbench 331 on which the work W is placed is provided inside the chamber 330 . A jig for holding the workpiece W in a predetermined posture may be provided on the workbench 331 .
In addition, the inside of the chamber 330 can be blocked from the outside air to be dustproof and moistureproof.
［ヘッドユニット］
　図３はヘッドユニット２２４をインクジェットヘッド１００によるインク吐出方向から見た底面図である。以下に行う、ヘッドユニット２２４及びインクジェットヘッド１００の説明においては、便宜上、インクジェットヘッド１００のノズル１１１の配列方向である描画幅方向を左右方向とし、ノズル１１１からの吐出方向に垂直となる平面上で左右方向に直交する方向を前後方向（走査方向ともいう）とし、左右方向と前後方向とに直交する方向（吐出方向）を上下方向として説明する。なお、これらの前後左右上下方向は、ヘッドユニット２２４をインクジェットヘッド１００について定めた方向であって、前述したロボットアーム３１０の説明における前後左右上下方向とは一致しない。
　また、インクジェットヘッド１００の図面の流路中の矢印は、インクの流れる方向を指す。
　また、以下の説明において、「～」は、その前後に記載される数値を下限値及び上限値として含む意味で使用する。 [Head unit]
FIG. 3 is a bottom view of the head unit 224 viewed from the ink ejection direction of the inkjet head 100. As shown in FIG. In the following description of the head unit 224 and the inkjet head 100, for convenience, the drawing width direction, which is the arrangement direction of the nozzles 111 of the inkjet head 100, is defined as the left-right direction, and the direction of ejection from the nozzles 111 is perpendicular to the direction of ejection. A direction orthogonal to the left-right direction is defined as a front-rear direction (also referred to as a scanning direction), and a direction orthogonal to the left-right direction and the front-rear direction (ejection direction) is defined as an up-down direction. Note that these front, back, left, right, up, and down directions are directions in which the head unit 224 is determined with respect to the inkjet head 100, and do not match the front, back, left, right, up, and down directions in the description of the robot arm 310 described above.
Also, the arrows in the flow path of the inkjet head 100 indicate the direction of ink flow.
Also, in the following description, "~" is used to mean that the numerical values before and after it are included as the lower limit and the upper limit.
　ヘッドユニット２２４は、複数のインクジェットヘッド１００を、吐出方向をそろえた状態で一体的に保持してユニット化したものである。ヘッドユニット２２４は、図３に示すように、左右方向に四つ並んだインクジェットヘッド１００の列が前後に二本配置されている。ヘッドユニット２２４においては、前側の列の各インクジェットヘッド１００のノズル１１１と後側の列の各インクジェットヘッド１００のノズル１１１とが前後方向から見て重ならないように、各インクジェットヘッド１００が千鳥状に配置されている。これにより、ヘッドユニット２２４は、ラインヘッドを構成し、左右方向に沿ったラインによる１パス方式の描画を行う。なお、インクジェットヘッド１００の並び数や列数は、一例であり、上記記載に限定されない。 The head unit 224 is a unit formed by integrally holding a plurality of inkjet heads 100 with their ejection directions aligned. As shown in FIG. 3, the head unit 224 has two rows of ink jet heads 100 arranged in the horizontal direction in two rows. In the head unit 224, the inkjet heads 100 are staggered so that the nozzles 111 of the inkjet heads 100 in the front row and the nozzles 111 of the inkjet heads 100 in the rear row do not overlap when viewed from the front-rear direction. are placed. As a result, the head unit 224 constitutes a line head, and performs one-pass drawing with lines extending in the left-right direction. Note that the number of rows and columns of the inkjet heads 100 is an example, and is not limited to the above description.
［インクジェットヘッド］
　図４Ａ，図４Ｂ及び図５はインクジェットヘッド１００、図６はヘッドチップ１、図７Ａ，図７Ｂは圧力室基板１３、図８Ａ，図８Ｂは流路スペーサー基板１２、図９はノズル基板１１、図１０Ａ，図１０Ｂ，図１１Ａ，図１１Ｂはヘッドチップ１を示す。なお、図７Ｂは圧力室基板１３の底面図と前述しているが、厳格には底面図ではなく、圧力室基板１３の底面を上方から透過して見た図である。図８Ｂも同様に、厳格には底面図ではなく、流路スペーサー基板１２の底面を上方から透過して見た図である。 [Inkjet head]
4A, 4B and 5 show the inkjet head 100, FIG. 6 shows the head chip 1, FIGS. 7A and 7B show the pressure chamber substrate 13, FIGS. 8A and 8B show the channel spacer substrate 12, FIG. 10A, 10B, 11A and 11B show the head chip 1. FIG. Although FIG. 7B is described as a bottom view of the pressure chamber substrate 13, strictly speaking, it is not a bottom view, but a view of the bottom surface of the pressure chamber substrate 13 seen through from above. Similarly, FIG. 8B is not strictly a bottom view, but is a view of the bottom face of the channel spacer substrate 12 seen through from above.
　インクジェットヘッド１００は、図４Ａ，図４Ｂ及び図５等に示すように、ヘッドチップ１と、ヘッドチップ１が配設された配線基板２と、配線基板２とフレキシブル基板３を介して接続された駆動回路基板４と、ヘッドチップ１内の圧力室１３１に供給するインクを貯留するマニホールド５と、内側にマニホールド５が収納された筐体６と、筐体６の底面開口を塞ぐように取り付けられたキャップ受板７と、筐体６に取り付けられたカバー部材９等を備えている。
　なお、図４Ａでは、マニホールド５の図示を省略しており、図４Ｂ及び図５では、カバー部材９の図示を省略している。
　また、本実施形態では、ヘッドチップ１のノズル１１１の列数が４列である例について説明するが、ノズル１１１の一列における並び数や列数や配置は適宜変更可能であり、例えば、列数は、１列から３列までのいずれかであってもよく、５列以上であってもよい。 As shown in FIGS. 4A, 4B, and 5, the ink jet head 100 includes a head chip 1, a wiring board 2 on which the head chip 1 is arranged, and a wiring board 2 and a flexible board 3 which are connected to each other. A drive circuit board 4, a manifold 5 for storing ink to be supplied to the pressure chambers 131 in the head chip 1, a housing 6 in which the manifold 5 is accommodated, and a bottom opening of the housing 6 are attached so as to close the opening. A cap receiving plate 7 mounted on the housing 6, a cover member 9 attached to the housing 6, and the like are provided.
It should be noted that illustration of the manifold 5 is omitted in FIG. 4A, and illustration of the cover member 9 is omitted in FIGS. 4B and 5 .
In this embodiment, an example in which the number of rows of the nozzles 111 of the head chip 1 is four will be described. may be any one of 1 to 3 columns, or may be 5 or more columns.
　ヘッドチップ１は、左右方向に長尺な略四角柱状の部材であり、圧力室基板１３と、流路スペーサー基板１２と、ノズル基板１１とが順に積層されて構成されている（図６～図１１Ｂ参照）。 The head chip 1 is a substantially square prism-shaped member elongated in the left-right direction, and is constructed by laminating a pressure chamber substrate 13, a channel spacer substrate 12, and a nozzle substrate 11 in order (FIGS. 6 to 8). 11B).
　圧力室基板１３には、圧力室１３１、空気室１３２及び共通インク排出路１３３等が設けられている（図６、図７Ａ及び図７Ｂ等参照）。
　圧力室１３１と空気室１３２は左右方向に交互に配置されるように多数設けられ、前後方向に４列で設けられている。
　圧力室１３１は、略矩形状の断面を有し上下方向に沿って形成されており、圧力室基板１３の上面に入口を有し、下面に出口を有している。また、圧力室１３１は、上方向の端部でインク貯留部５１に連通しており、圧力室１３１には当該インク貯留部５１からインクが供給され、圧力室１３１内部にはノズル１１１から射出するためのインクを貯留する。また、圧力室１３１は、圧力室基板１３と流路スペーサー基板１２とにまたがって、同一面積の略矩形状の断面を有するように上下方向に沿って形成されており、下方向の端部でノズル１１１に連通している（図１０Ａ、図１０Ｂ等参照。）。 The pressure chamber substrate 13 is provided with pressure chambers 131, air chambers 132, a common ink discharge path 133, and the like (see FIGS. 6, 7A, 7B, etc.).
A large number of pressure chambers 131 and air chambers 132 are provided so as to be alternately arranged in the left-right direction, and are provided in four rows in the front-rear direction.
The pressure chamber 131 has a substantially rectangular cross section and is formed along the vertical direction, and has an inlet on the upper surface of the pressure chamber substrate 13 and an outlet on the lower surface. The pressure chamber 131 communicates with the ink reservoir 51 at its upper end, and ink is supplied from the ink reservoir 51 to the pressure chamber 131 and ejected from the nozzle 111 into the pressure chamber 131 . stores ink for Further, the pressure chamber 131 is formed along the vertical direction so as to have a substantially rectangular cross section with the same area, straddling the pressure chamber substrate 13 and the channel spacer substrate 12. It communicates with the nozzle 111 (see FIGS. 10A, 10B, etc.).
　空気室１３２は、圧力室１３１よりもやや大きい略矩形状の断面を有し上下方向に沿って圧力室１３１と平行になるように形成されている。また、空気室１３２は、圧力室１３１とは異なり、インク貯留部５１には連通されておらず、空気室１３２内にインクが流れ込まないようになっている。また、空気室１３２は、ノズル１１１にも連通されていない（図１０Ａ、図１０Ｂ等参照。）。 The air chamber 132 has a substantially rectangular cross section slightly larger than the pressure chamber 131 and is formed parallel to the pressure chamber 131 along the vertical direction. Also, unlike the pressure chamber 131 , the air chamber 132 is not communicated with the ink reservoir 51 , so that ink does not flow into the air chamber 132 . Also, the air chamber 132 is not communicated with the nozzle 111 (see FIGS. 10A, 10B, etc.).
　圧力室１３１と空気室１３２とは、圧電材料によって形成された圧力発生手段としての隔壁１３６により隔てられて形成されている（図１１Ａ参照。）。隔壁１３６には図示しない駆動電極が設けられており、これら隔壁１３６及び駆動電極によってアクチュエーターが構成されている。そして、当該駆動電極に電圧が印加されると、隣接する圧力室１３１間の隔壁１３６部分がシェアモード型の変位を繰り返すことで、圧力室１３１内のインクに圧力が加えられる。なお、図６～図１１Ｂ等に示す圧力室１３１では、片側にしか隔壁１３６を有しない左右方向の端部に位置する圧力室１３１は使用しておらず、それ以外の両側に隔壁１３６を有する圧力室１３１を使用している。 The pressure chamber 131 and the air chamber 132 are separated by a partition wall 136 as a pressure generating means made of piezoelectric material (see FIG. 11A). A drive electrode (not shown) is provided on the partition 136, and the partition 136 and the drive electrode constitute an actuator. When a voltage is applied to the drive electrode, the partition wall 136 portion between the adjacent pressure chambers 131 repeats shear mode displacement, thereby applying pressure to the ink in the pressure chambers 131 . In the pressure chambers 131 shown in FIGS. 6 to 11B and the like, the pressure chambers 131 located at the ends in the left-right direction, which have partition walls 136 only on one side, are not used, and the other pressure chambers 131 have partition walls 136 on both sides. A pressure chamber 131 is used.
　インクジェットヘッド１００においては、いわゆるメニスカス揺らしを行うものが好ましい。メニスカス揺らしは、揺らし波形に基づいて圧力室１３１の容積を一定の範囲で連続的に往復変動させ、インクを吐出せずに、ノズル１１１内のインクが形成するメニスカス（屈曲した界面）、ノズル１１１内、圧力室１３１内のインクを振動させるものである。
　ここで、「揺らし波形」とは、液滴吐出を行う収縮のパルスより弱い駆動パルスで、圧力波しか生じない範囲で圧力室の容積を収縮又は膨張させる収縮又は膨張のパルスであり、ノズル付近の液体（インク）が乾燥して粘度増加することによる目詰まり（デキャップ）の抑制を目的として、ノズル内の液体の界面を揺らすための波形である。
　したがって、インクを吐出しないとき（非描画時）に、ノズル循環及びメニスカス揺らしを行っておくことにより、ノズル１１１内のインクが撹拌されるので、次に吐出（描画）を行うときに、沈降によるノズル詰まりやノズル１１１内のインク増粘による吐出不良を抑制することができ、吐出速度の低下を抑えることができる。
　具体的には、圧力室１３１内のインクへ圧力を付与する前記アクチュエーター（隔壁１３６及び駆動電極等）によって、ノズル１１１からインクを吐出させる駆動波形よりも電圧が小さく、圧力室１３１内のインクの界面を振動させる揺らし波形を印加する。 In the inkjet head 100, it is preferable to perform so-called meniscus oscillation. Meniscus rocking continuously reciprocates the volume of the pressure chamber 131 within a certain range based on the rocking waveform, and without ejecting ink, the meniscus (bent interface) formed by the ink in the nozzle 111 and the nozzle 111 . Among them, the ink in the pressure chamber 131 is vibrated.
Here, the “fluctuation waveform” is a drive pulse weaker than the contraction pulse for ejecting droplets, and is a contraction or expansion pulse that contracts or expands the volume of the pressure chamber within a range where only pressure waves are generated. It is a waveform for shaking the interface of the liquid in the nozzle for the purpose of suppressing clogging (decap) due to the liquid (ink) drying and increasing in viscosity.
Therefore, by performing nozzle circulation and meniscus oscillation when ink is not ejected (non-drawing), the ink in the nozzles 111 is agitated. It is possible to suppress ejection defects due to nozzle clogging and ink thickening in the nozzles 111, and to suppress a decrease in ejection speed.
Specifically, the actuator (partition wall 136, drive electrode, etc.) that applies pressure to the ink in the pressure chamber 131 has a lower voltage than the drive waveform for ejecting the ink from the nozzle 111, and the pressure of the ink in the pressure chamber 131 is reduced. A rocking waveform is applied to oscillate the interface.
　なお、空気室１３２を設けずに圧力室１３１のみで形成してもよいが、上述したとおり、圧力室１３１と空気室１３２とを交互に設けることが好ましい。これにより、圧力室１３１同士が隣接しないようできるため、一の圧力室１３１に隣接する隔壁１３６が変形した際に、他の圧力室１３１に影響しないようにできる。 Although the pressure chambers 131 may be formed without the air chambers 132, it is preferable to alternately provide the pressure chambers 131 and the air chambers 132 as described above. As a result, the pressure chambers 131 can be prevented from being adjacent to each other, so that when the partition wall 136 adjacent to one pressure chamber 131 is deformed, the other pressure chambers 131 are not affected.
　共通インク排出路１３３は、第１共通インク排出路１３４と第２共通インク排出路１３５とが連結して構成されている（図６及び図７（Ｂ）等参照）。
　第１共通インク排出路１３４は、圧力室基板１３の下面側に、圧力室１３１及び空気室１３２が設けられた部分を避けるようにして、ヘッドチップ１の前側、後側、及びそれらの中央部に、３列並んで左右方向に沿って設けられている。また、第１共通インク排出路１３４の下面側には、流路スペーサー基板１２に設けられた個別インク排出路１２１が複数連結しており、それら個別インク排出路１２１（第２個別インク排出路１２３）から流れてくるインクが第１共通インク排出路１３４で合流できるようになっている（図７Ｂ、図８Ａ及び図１０Ａ）。また、第１共通インク排出路１３４は、右端部付近で、ヘッドチップ１外にインクを排出可能な第２共通インク排出路１３５に連結している。したがって、第１共通インク排出路１３４は、個別インク排出路１２１（第２個別インク排出路１２３）から流れてきたインクが、当該第２共通インク排出路１３５に向かって流れる流路となっている。 The common ink discharge path 133 is configured by connecting a first common ink discharge path 134 and a second common ink discharge path 135 (see FIGS. 6 and 7B, etc.).
The first common ink discharge path 134 is formed on the lower surface side of the pressure chamber substrate 13 so as to avoid the portion where the pressure chambers 131 and the air chambers 132 are provided, and extends on the front and rear sides of the head chip 1 and their central portions. , are provided along the left-right direction in three rows. A plurality of individual ink discharge paths 121 provided on the channel spacer substrate 12 are connected to the lower surface side of the first common ink discharge path 134, and these individual ink discharge paths 121 (second individual ink discharge paths 123 ) can merge in the first common ink discharge path 134 (FIGS. 7B, 8A and 10A). Also, the first common ink discharge path 134 is connected near the right end to a second common ink discharge path 135 capable of discharging ink to the outside of the head chip 1 . Therefore, the first common ink discharge path 134 serves as a flow path through which the ink flowing from the individual ink discharge path 121 (the second individual ink discharge path 123) flows toward the second common ink discharge path 135. .
　第２共通インク排出路１３５は、圧力室１３１と同様に、上下方向に沿って形成されている。また、第２共通インク排出路１３５は、圧力室基板１３の下面側は第１共通インク排出路１３４に連通し、上面側は排出用液室５７に連通しており、第１共通インク排出路１３４から流れてきたインクを上側（ノズル基板１１側とは反対側）に向かって、ヘッドチップ１の外部に排出するための流路となっている。また、第２共通インク排出路１３５は、ヘッドチップ１の右端部付近に設けられ、第１共通インク排出路１３４に連通している。また、第２共通インク排出路１３５は、個々の圧力室１３１よりも大きな容積を有するように設けることによって、インクの排出効率を高めることができる。 The second common ink discharge path 135 is formed along the vertical direction, like the pressure chambers 131 . The second common ink discharge path 135 communicates with the first common ink discharge path 134 on the lower surface side of the pressure chamber substrate 13, and communicates with the discharge liquid chamber 57 on the upper surface side of the pressure chamber substrate 13. It is a flow path for discharging the ink flowing from 134 toward the upper side (the side opposite to the nozzle substrate 11 side) to the outside of the head chip 1 . The second common ink discharge path 135 is provided near the right end of the head chip 1 and communicates with the first common ink discharge path 134 . Further, by providing the second common ink discharge path 135 so as to have a volume larger than that of the individual pressure chambers 131, the ink discharge efficiency can be improved.
　流路スペーサー基板１２には、圧力室１３１と、当該圧力室１３１から分岐して設けられている個別インク排出路１２１とが形成されている（図１０Ａ及び図１０Ｂ等参照）。
　圧力室１３１は、流路スペーサー基板１２と圧力室基板１３とをまたがって、同一面積の略矩形状の断面を有するように上下方向に沿って形成されている。 Pressure chambers 131 and individual ink discharge paths 121 branched from the pressure chambers 131 are formed in the channel spacer substrate 12 (see FIGS. 10A and 10B, etc.).
The pressure chambers 131 are formed along the vertical direction so as to straddle the channel spacer substrate 12 and the pressure chamber substrate 13 and have substantially rectangular cross sections with the same area.
　個別インク排出路１２１は、一端部が圧力室１３１と連結し、他端部が第１共通インク排出路１３４に連結しており、圧力室１３１のインクを第１共通インク排出路１３４に排出する流路となっている。
　個別インク排出路１２１は、気泡や異物等をインクとともに排出しやすくする観点からノズル１１１の吐出開口に対して、二つ以上設けられている。すなわち、個別インク排出路１２１は、圧力室１３１の各々に少なくとも二つ以上設けられている。また、個別インク排出路１２１は、例えば、図１０Ａ及び図１０Ｂに示すように、圧力室１３１の前方向と後方向にそれぞれ一つずつ、計二つ設け、気泡や異物等をインクとともに排出しやすくする効果を得ることができ、かつ製造効率も高いため好ましい。 One end of the individual ink discharge path 121 is connected to the pressure chamber 131 and the other end is connected to the first common ink discharge path 134 to discharge the ink in the pressure chamber 131 to the first common ink discharge path 134 . It is a flow channel.
Two or more individual ink discharge paths 121 are provided with respect to the ejection opening of the nozzle 111 from the viewpoint of facilitating the discharge of air bubbles, foreign substances, etc. together with the ink. That is, at least two individual ink discharge paths 121 are provided in each pressure chamber 131 . Also, as shown in FIGS. 10A and 10B, for example, two individual ink discharge paths 121 are provided one each in the forward direction and the rearward direction of the pressure chamber 131 to discharge air bubbles, foreign matters, etc. together with the ink. It is preferable because it is possible to obtain the effect of facilitating production and the production efficiency is high.
　流路スペーサー基板１２は、個別インク排出路１２１の加工がし易い（精度が高い）という観点や、熱伝導度が高いためインク温度を均一に保ちやすくすることができるという観点から、シリコーン、ステンレス鋼（ＳＵＳ）又は４２アロイからなる基板であることが好ましい。また、これらのうち、圧力室基板１３を形成する材料と熱膨張係数の近い材料の基板を使用することが好ましい。 The flow path spacer substrate 12 is made of silicone, stainless steel, etc., from the viewpoints that the individual ink discharge paths 121 can be easily processed (with high precision) and that the temperature of the ink can be easily kept uniform due to its high thermal conductivity. A substrate made of steel (SUS) or 42 alloy is preferred. Among these, it is preferable to use a substrate made of a material having a coefficient of thermal expansion close to that of the material forming the pressure chamber substrate 13 .
　ノズル基板１１には、厚さ方向（上下方向）に貫通する孔であるノズル１１１が設けられている（図９参照。）。ノズル１１１は、圧力室１３１に連通しており、圧力室１３１内のインクに圧力が加えられた際に、圧力室１３１内に貯留されたインクを射出する射出口（吐出開口）となっている。また、本実施形態におけるノズル１１１は、左右方向に配列されるとともに、前後方向に四つの列をなしている。 The nozzle substrate 11 is provided with a nozzle 111 which is a hole penetrating in the thickness direction (vertical direction) (see FIG. 9). The nozzle 111 communicates with the pressure chamber 131 and serves as an ejection opening (ejection opening) for ejecting the ink stored in the pressure chamber 131 when pressure is applied to the ink in the pressure chamber 131 . . Further, the nozzles 111 in this embodiment are arranged in the horizontal direction and form four rows in the front-rear direction.
　また、ノズル基板１１は、図１０Ａ及び図１０Ｂ等に示すように、第１個別インク排出路１２２の流路壁のうち一つを構成していることが好ましい。また、ノズル基板１１は厚さが薄いため、圧力によりわずかに弾性変形して流路の容積を変更可能なダンパーとして機能することができる。 Also, as shown in FIGS. 10A and 10B, etc., the nozzle substrate 11 preferably constitutes one of the channel walls of the first individual ink discharge channel 122 . In addition, since the nozzle substrate 11 is thin, it can function as a damper capable of changing the volume of the flow path by slightly elastically deforming due to pressure.
　ノズル基板１１は、ポリイミド樹脂、ポリエチレンテレフタラート樹脂、ポリアミド樹脂、ポリサルフォン樹脂等からなる基板を用いることが好ましい。これにより、樹脂基板をレーザー加工により高精度に加工してノズル基板１１を製造することができ、優れたインク耐性も有することとなるため好ましい。また、これらの樹脂基板は高弾性であるので、第１個別インク供給路の流路壁として好適に用いることができる。
　また、ノズル基板１１は、シリコーン基板に対してエッチング加工することよって製造することもできる。 The nozzle substrate 11 is preferably made of polyimide resin, polyethylene terephthalate resin, polyamide resin, polysulfone resin, or the like. Accordingly, the nozzle substrate 11 can be manufactured by processing the resin substrate with high accuracy by laser processing, and the nozzle substrate 11 has excellent ink resistance, which is preferable. Moreover, since these resin substrates have high elasticity, they can be suitably used as the channel walls of the first individual ink supply channels.
The nozzle substrate 11 can also be manufactured by etching a silicone substrate.
　また、ヘッドチップ１内でインクの流路となる圧力室１３１、個別インク排出路１２１及び共通インク排出路１３３の流路表面には、流路保護の観点から、耐インク性を有する保護膜が設けられていることが好ましい。
　保護膜は、耐インク性を有するものであれば特に限られないが、例えば、ポリパラキシリレン又はその誘導体を含有する膜（以下、パリレン膜ともいう。）を用いることが好ましい。
　パリレン膜は、パラキシリレン樹脂又はその誘導体樹脂からなる樹脂被膜であり、例えば、固体のジパラキシリレンダイマー又はその誘導体を蒸着源とする気相合成法（Ｃｈｅｍｉｃａｌ　Ｖａｐｅｒ　Ｄｅｐｏｓｉｔｉｏｎ：ＣＶＤ法）により形成することができる。すなわち、ジパラキシリレンダイマーが気化、熱分解して発生したパラキシリレンラジカルが、流路部材や金属層の表面に吸着して重合反応し、被膜を形成する。 In addition, from the viewpoint of protecting the flow paths, a protective film having ink resistance is formed on the flow path surfaces of the pressure chambers 131, the individual ink discharge paths 121, and the common ink discharge path 133, which serve as ink flow paths in the head chip 1. is preferably provided.
The protective film is not particularly limited as long as it has ink resistance. For example, it is preferable to use a film containing polyparaxylylene or a derivative thereof (hereinafter also referred to as a parylene film).
The parylene film is a resin film made of a paraxylylene resin or a derivative resin thereof, and may be formed, for example, by a chemical vapor deposition (CVD) method using a solid di-paraxylylene dimer or a derivative thereof as a vapor deposition source. can be done. That is, the para-xylylene radicals generated by the vaporization and thermal decomposition of the di-para-xylylene dimer are adsorbed on the surface of the flow channel member and the metal layer, undergo a polymerization reaction, and form a film.
　パリレン膜には、種々の性能を有するパリレン膜があるが、必要な性能等に応じて、各種のパリレン膜やそれら種々のパリレン膜を複数積層した多層構成のパリレン膜等を所望のパリレン膜として適用することもできる。パリレン膜の層厚は、優れた絶縁性及び耐インク性の効果を得る観点から、５～２０μｍの範囲内とすることが好ましい。 Parylene films include parylene films having various performances, and depending on the required performance, various parylene films and multi-layered parylene films in which a plurality of these various parylene films are laminated are used as desired parylene films. can also be applied. The layer thickness of the parylene film is preferably in the range of 5 to 20 μm from the viewpoint of obtaining excellent insulation and ink resistance effects.
　ポリパラキシリレンは分子量が５０万にも及ぶ結晶性ポリマーであり、原料のパラキシリレン二量体を昇華し熱分解してパラキシリレンラジカルを発生させる。パラキシリレンラジカルはスペーサー基板に付着すると同時に重合してポリパラキシリレンを生成し、保護膜を形成する。 Poly-para-xylylene is a crystalline polymer with a molecular weight as high as 500,000, and the raw material para-xylylene dimer is sublimated and thermally decomposed to generate para-xylylene radicals. Para-xylylene radicals attach to the spacer substrate and simultaneously polymerize to form poly-para-xylylene to form a protective film.
　ポリパラキシリレンとしては、パリレンＮ（日本パリレン株式会社製の商品名）が挙げられる。
　ポリパラキシリレン誘導体としては、ベンゼン環に塩素原子が一つ置換したパリレンＣ（日本パリレン株式会社製の商品名）、ベンゼン環の２位と５位に塩素原子が置換したパリレンＤ（日本パリレン株式会社製の商品名）、ベンゼン環を結ぶメチレン基の水素原子をフッ素原子で置換したパリレンＨＴ（日本パリレン株式会社製の商品名）が挙げられる。
　本実施形態のポリパラキシリレン及びポリパラキシリレンの誘導体としては、これらの中でも、上述した層厚で優れた絶縁性及び耐インク性の効果を得る観点から、パリレンＮ又はパリレンＣを用いることが好ましい。 Examples of polyparaxylylene include Parylene N (trade name of Japan Parylene Co., Ltd.).
Examples of polyparaxylylene derivatives include Parylene C (trade name of Nippon Parylene Co., Ltd.) in which one chlorine atom is substituted on the benzene ring, and Parylene D (Nippon Parylene (trade name, manufactured by Nippon Parylene Co., Ltd.), and Parylene HT (trade name, manufactured by Japan Parylene Co., Ltd.) in which hydrogen atoms of methylene groups connecting benzene rings are substituted with fluorine atoms.
Among these, parylene N or parylene C is used as the polyparaxylylene and the polyparaxylylene derivative of the present embodiment from the viewpoint of obtaining the effects of excellent insulation and ink resistance with the above-described layer thickness. is preferred.
　なお、本実施形態の第１個別インク排出路１２２は、流路スペーサー基板１２の下面側部分に設けられていることとしたが、これに限られない。例えば、第１個別インク排出路１２２を、ノズル基板１１と流路スペーサー基板１２の両方に跨るように設けてもよいし、ノズル基板１１にのみ設けてもよいし、流路スペーサー基板１２の底面よりも少し上側に設けてノズル基板１１に隣接しないように設けてもよい。 Although the first individual ink discharge path 122 in this embodiment is provided on the lower surface side portion of the flow path spacer substrate 12, it is not limited to this. For example, the first individual ink discharge path 122 may be provided across both the nozzle substrate 11 and the flow path spacer substrate 12, may be provided only on the nozzle substrate 11, or may be provided on the bottom surface of the flow path spacer substrate 12. It may be provided slightly above the nozzle substrate 11 so as not to be adjacent to the nozzle substrate 11 .
　ヘッドチップ１の上面には、図５に示すように、配線基板２が配設され、配線基板２の前後方向に沿った両縁部に、駆動回路基板４と接続された二つのフレキシブル基板３が配設されている。 As shown in FIG. 5, a wiring board 2 is arranged on the upper surface of the head chip 1, and two flexible boards 3 connected to a driving circuit board 4 are provided on both edges of the wiring board 2 along the front-rear direction. are arranged.
　配線基板２は、左右方向に長尺な略矩形板状に形成されており、その略中央部に開口部２２を有している。配線基板２の左右方向及び前後方向の各幅は、ヘッドチップ１よりもそれぞれ大きく形成されている。 The wiring board 2 is formed in a substantially rectangular plate shape elongated in the left-right direction, and has an opening 22 in its substantially central portion. The widths of the wiring board 2 in the left-right direction and the width in the front-rear direction are formed to be larger than those of the head chip 1 .
　開口部２２は、左右方向に長尺な略矩形状に形成されており、配線基板２にヘッドチップ１が取り付けられた状態においては、ヘッドチップ１における各圧力室１３１の入口と、第２共通インク排出路１３５の出口とを上側に露出させるようになっている。 The opening 22 is formed in a substantially rectangular shape elongated in the left-right direction. The outlet of the ink discharge path 135 is exposed upward.
　フレキシブル基板３は、駆動回路基板４と配線基板２の電極部とを電気的に接続させており、駆動回路基板４からの信号をフレキシブル基板３を介してヘッドチップ１内の隔壁１３６に設けられた駆動電極に印加できるようになっている。 The flexible board 3 electrically connects the driving circuit board 4 and the electrode part of the wiring board 2, and the signal from the driving circuit board 4 is provided to the partition wall 136 in the head chip 1 through the flexible board 3. can be applied to the drive electrodes.
　また、配線基板２の外縁部には、マニホールド５の下端部が接着により取り付け固定されている。すなわち、マニホールド５は、ヘッドチップ１の圧力室１３１の入口側（上側）に配置され、配線基板２を介してヘッドチップ１と連結されている。 In addition, the lower end of the manifold 5 is attached and fixed to the outer edge of the wiring board 2 by adhesion. That is, the manifold 5 is arranged on the inlet side (upper side) of the pressure chamber 131 of the head chip 1 and connected to the head chip 1 via the wiring substrate 2 .
　マニホールド５は、樹脂により成形されてなる部材であり、ヘッドチップ１の圧力室１３１の上部に設けられ、圧力室１３１に導入されるインクを貯留するものである。具体的には、図４Ｂ等に示すように、マニホールド５は、左右方向に長尺に形成されており、インク貯留部５１を構成する中空状の本体部５２と、インク流路を構成する第１～第４インクポート５３～５６とを備えている。また、インク貯留部５１は、インク中のゴミを除去するためのフィルターＦによって、上側の第１液室５１ａと下側の第２液室５１ｂの二つ区画されている。 The manifold 5 is a member molded from resin, is provided above the pressure chambers 131 of the head chip 1, and stores ink introduced into the pressure chambers 131. Specifically, as shown in FIG. 4B and the like, the manifold 5 is elongated in the left-right direction, and includes a hollow main body portion 52 that forms an ink reservoir 51 and a hollow main body portion 52 that forms an ink flow path. 1st to 4th ink ports 53 to 56 are provided. The ink reservoir 51 is divided into two chambers, a first liquid chamber 51a on the upper side and a second liquid chamber 51b on the lower side, by a filter F for removing dust in the ink.
　第１インクポート５３は、第１液室５１ａの右側上端部に連通されており、インク貯留部５１へのインクの導入に用いられる。また、第１インクポート５３の先端部には、第１ジョイント８１ａが外挿されている。
　第２インクポート５４は、第１液室５１ａの左側上端部に連通されており、第１液室５１ａ内の気泡を除去するために用いられる。また、第２インクポート５４の先端部には、第２ジョイント８１ｂが外挿されている。
　第３インクポート５５は、第２液室５１ｂの左側上端部に連通されており、第２液室５１ｂ内の気泡を除去するために用いられる。また、第３インクポート５５の先端部には、第３ジョイント８２ａが外挿されている。
　第４インクポート５６は、ヘッドチップ１の第２共通インク排出路１３５に連通する排出用液室５７に連通されており、ヘッドチップ１から排出されたインクが、第４インクポート５６を通して、インクジェットヘッド１００の外部に排出される。 The first ink port 53 communicates with the upper right end of the first liquid chamber 51 a and is used to introduce ink into the ink reservoir 51 . A first joint 81a is externally inserted at the tip of the first ink port 53. As shown in FIG.
The second ink port 54 communicates with the upper left end of the first liquid chamber 51a and is used to remove air bubbles in the first liquid chamber 51a. A second joint 81b is externally fitted to the tip of the second ink port 54. As shown in FIG.
The third ink port 55 communicates with the upper left end of the second liquid chamber 51b and is used to remove air bubbles in the second liquid chamber 51b. A third joint 82 a is externally inserted at the tip of the third ink port 55 .
The fourth ink port 56 communicates with a discharge liquid chamber 57 that communicates with the second common ink discharge path 135 of the head chip 1, and the ink discharged from the head chip 1 passes through the fourth ink port 56 to the inkjet printer. It is discharged outside the head 100 .
　筐体６は、例えば、アルミニウムを材料としてダイキャスト法により成形されてなる部材であり、左右方向に長尺に形成されている。また、筐体６は、その内側にヘッドチップ１、配線基板２及びフレキシブル基板３が取り付けられたマニホールド５を収納可能に形成されてなり、当該筐体６の底面が開放されている。また、筐体６の左右方向の両端部には、当該筐体６をプリンタ本体側に取り付けるための取付用孔６８がそれぞれ形成されている。 The housing 6 is, for example, a member formed by die casting using aluminum as a material, and is elongated in the left-right direction. The housing 6 is formed so as to accommodate the manifold 5 to which the head chip 1, the wiring substrate 2 and the flexible substrate 3 are attached, and the bottom of the housing 6 is open. Mounting holes 68 for mounting the housing 6 to the main body of the printer are formed at both ends of the housing 6 in the left-right direction.
　キャップ受板７は、その略中央部に左右方向に長尺なノズル用開口部７１が形成されており、ノズル基板１１がノズル用開口部７１を介して露出するようにして、筐体６の底面開口を塞ぐように取り付けられている。 The cap receiving plate 7 has an elongated nozzle opening 71 formed in a substantially central portion thereof in the left-right direction. It is installed so as to close the bottom opening.
［インク循環装置］
　図１２はインク循環装置８を示す模式図である。
　インクジェットヘッド１００は、吐出直前には粘度が低く、吐出後は粘度が高くなるチキソ性を有するインクの利用に特に好適な循環構造としてのインク循環装置８が併設されている。
　インク循環装置８は、ノズル１１１の吐出開口に対して第１共通インク排出路１３４及び第２共通インク排出路１３５を通じてインクを循環させることができる。
　インク循環装置８は、圧力室のうちノズルに連通する流路における平均せん断速度が１０００［１／ｓ］以上、１００００［１／ｓ］以下となるように制御する。
　ここで、「平均せん断速度」とは、吐出時ではなく、循環時の平均せん断速度をいう。また、「ノズルに連通する流路」とは、図１０Ａにおける符号Ｒで示されるように圧力室１３１のうちノズル近傍の流路をいう。「ノズル近傍の流路」とは、ノズル最近傍の流路部品で構成される流路をいい、具体的には流路スペーサー基板１２で構成された流路Ｒをいう。 [Ink circulation device]
FIG. 12 is a schematic diagram showing the ink circulation device 8. As shown in FIG.
The inkjet head 100 is also provided with an ink circulation device 8 as a circulation structure that is particularly suitable for using thixotropic ink that has a low viscosity immediately before ejection and a high viscosity after ejection.
The ink circulation device 8 can circulate ink through the first common ink discharge path 134 and the second common ink discharge path 135 to the ejection openings of the nozzles 111 .
The ink circulation device 8 controls the average shear velocity in the flow path communicating with the nozzles in the pressure chamber to be 1000 [1/s] or more and 10000 [1/s] or less.
Here, the "average shear rate" refers to the average shear rate during circulation, not during discharge. Further, the "channel communicating with the nozzle" refers to the channel in the vicinity of the nozzle in the pressure chamber 131, as indicated by symbol R in FIG. 10A. The “channel near the nozzle” refers to the channel configured by the channel components closest to the nozzle, specifically the channel R configured by the channel spacer substrate 12 .
　平均せん断速度は、下記式により算出したものである。
　平均せん断速度＝平均流速÷代表円管の半径
　代表円管の半径＝円でない流路の場合は（断面積÷π）の正の平方根　単ノズルの循環流量＝全ノズルの循環流量（「循環流量Ｑ」ともいう。）（実測値）÷ノズル数
　平均流速＝単ノズルの循環流量÷ノズルに連通する流路における断面積 The average shear rate is calculated by the following formula.
Average shear rate = average flow velocity / radius of representative circular pipe Radius of representative circular pipe = positive square root of (cross-sectional area / π) in the case of a non-circular channel Circulation flow rate of single nozzle = circulation flow rate of all nozzles (Also referred to as "Q".) (Actual value) ÷ Number of nozzles Average flow rate = Circulating flow rate of single nozzle ÷ Cross-sectional area in flow path communicating with nozzle
　インク循環装置８は、ノズル１１１に連通する流路における平均せん断速度が１０００～１００００［１／ｓ］の範囲で設定されたせん断速度となるように制御する。
　平均せん断速度を前記範囲内に制御するための手段としては、前記した平均せん断速度を算出する式から分かるとおり、例えば、前記全ノズルの循環流量Ｑを制御することが挙げられる。
　また、前記循環流量Ｑは、下記式により算出することができることから、当該循環流量Ｑを制御するために、インクジェットヘッド１００のインク流路を構成する第１及び第４インクポート５３及び５６（図１２参照）における循環差圧（圧力差）（ヘッドのＩＮＬＥＴとＯＵＴＬＥＴの差圧）を調整することが挙げられる。具体的には、制御部２４０は、インク循環装置８のポンプ８８に加えられる圧力や、各サブタンク８１及び８２内のインク充填量と、各サブタンク８１及び８２の上下方向（重力方向）の位置とを適宜変更することによって圧力Ｐ１及び圧力Ｐ２を調整し、圧力Ｐ１及び圧力Ｐ２の圧力差（循環差圧ΔＰ）によってノズルに連通するインク流量（循環流量Ｑ）を制御する。
　［式］　循環流量Ｑ＝循環差圧ΔＰ／ヘッド流路抵抗Ｒ
（前記循環差圧ΔＰは、前記第１及び第４インクポート５３及び５６における循環差圧を表す。前記ヘッド流路抵抗は、第４インクポート５６から第１インクポート５３までの流路抵抗を表す） The ink circulation device 8 controls the average shear rate in the flow path communicating with the nozzle 111 to be the shear rate set in the range of 1000 to 10000 [1/s].
As can be seen from the formula for calculating the average shear rate, means for controlling the average shear rate within the above range include, for example, controlling the circulating flow rate Q of all the nozzles.
Further, since the circulation flow rate Q can be calculated by the following formula, in order to control the circulation flow rate Q, the first and fourth ink ports 53 and 56 (Fig. 12) (the differential pressure between the INLET and the OUTLET of the head). Specifically, the control unit 240 controls the pressure applied to the pump 88 of the ink circulation device 8, the amount of ink filled in each of the sub-tanks 81 and 82, and the vertical (gravitational) position of each of the sub-tanks 81 and 82. are appropriately changed to adjust the pressure P1 and the pressure P2, and the ink flow rate (circulation flow rate Q) communicating with the nozzles is controlled by the pressure difference (circulation differential pressure ΔP) between the pressures P1 and P2.
[Formula] Circulation flow rate Q = Circulation differential pressure ΔP / Head channel resistance R
(The circulating differential pressure ΔP represents the circulating differential pressure in the first and fourth ink ports 53 and 56. The head flow path resistance is the flow path resistance from the fourth ink port 56 to the first ink port 53. show)
　インク循環装置８は、インクジェットヘッド１００内の圧力室１３１から個別インク排出路１２１へのインクの循環流を発生させるためのインクの供給手段である。インク循環装置８は、供給用サブタンク８１、循環用サブタンク８２及びメインタンク８３等によって構成されている（図１２参照）。 The ink circulation device 8 is an ink supply means for generating a circulation flow of ink from the pressure chambers 131 in the inkjet head 100 to the individual ink discharge paths 121 . The ink circulation device 8 is composed of a supply sub-tank 81, a circulation sub-tank 82, a main tank 83, and the like (see FIG. 12).
　供給用サブタンク８１は、マニホールド５のインク貯留部５１に供給するためのインクが充填されており、インク流路８４によって第１インクポート５３に接続されている。
　循環用サブタンク８２は、マニホールド５の排出用液室５７から排出されたインクが充填されており、インク流路８５によって第４インクポート５６に接続されている。
　また、供給用サブタンク８１と循環用サブタンク８２は、ヘッドチップ１のノズル面（以下、「位置基準面」ともいう。）に対して、上下方向（重力方向）に異なる位置に設けられている。これによって、当該位置基準面と供給用サブタンク８１の水頭差による圧力Ｐ１と、当該位置基準面と循環用サブタンク８２との水頭差による圧力Ｐ２が生じている。
　また、供給用サブタンク８１と循環用サブタンク８２は、インク流路８６で接続されている。そして、ポンプ８８によって加えられた圧力によって、循環用サブタンク８２から供給用サブタンク８１にインクを戻すことができる。 The supply sub-tank 81 is filled with ink to be supplied to the ink reservoir 51 of the manifold 5 and is connected to the first ink port 53 by an ink flow path 84 .
The circulation sub-tank 82 is filled with the ink discharged from the discharge liquid chamber 57 of the manifold 5 and is connected to the fourth ink port 56 by the ink channel 85 .
The supply sub-tank 81 and the circulation sub-tank 82 are provided at different positions in the vertical direction (gravitational direction) with respect to the nozzle surface of the head chip 1 (hereinafter also referred to as the "position reference plane"). As a result, a pressure P1 due to a water head difference between the position reference plane and the supply sub-tank 81 and a pressure P2 due to a water head difference between the position reference plane and the circulation sub-tank 82 are generated.
The supply sub-tank 81 and the circulation sub-tank 82 are connected by an ink flow path 86 . Then, the pressure applied by the pump 88 can return the ink from the circulation sub-tank 82 to the supply sub-tank 81 .
　メインタンク８３は、供給用サブタンク８１に供給するためのインクが充填されており、インク流路８７によって供給用サブタンク８１に接続されている。そして、ポンプ８９によって加えられた圧力によって、メインタンク８３から供給用サブタンク８１にインクを供給することができる。 The main tank 83 is filled with ink to be supplied to the supply sub-tank 81 and is connected to the supply sub-tank 81 by an ink flow path 87 . Ink can be supplied from the main tank 83 to the supply sub-tank 81 by the pressure applied by the pump 89 .
　また、各サブタンク内のインク充填量と、各サブタンクの上下方向（重力方向）の位置とを適宜変更することによって、圧力Ｐ１及び圧力Ｐ２を調整することができる。そして、圧力Ｐ１及び圧力Ｐ２の圧力差によって、適宜の循環流速で、インクジェットヘッド１００内のインクを循環できる。これにより、ヘッドチップ１内に発生した気泡や異物等を除去し、ノズル１１１の詰まりや、射出不良等を抑制することができる。
　また、制御部２４０は、圧力Ｐ１及び圧力Ｐ２の圧力差を調整してインク循環量が30[ml/min]以上300[ml/min]以下となるように制御を行う。 Further, the pressure P1 and the pressure P2 can be adjusted by appropriately changing the amount of ink filled in each sub-tank and the position of each sub-tank in the vertical direction (the direction of gravity). The pressure difference between the pressures P1 and P2 allows the ink in the inkjet head 100 to circulate at an appropriate circulation flow rate. As a result, it is possible to remove air bubbles, foreign matter, and the like generated in the head chip 1, thereby suppressing clogging of the nozzles 111, ejection failure, and the like.
Further, the control unit 240 controls the pressure difference between the pressure P1 and the pressure P2 so that the ink circulation rate is 30 [ml/min] or more and 300 [ml/min] or less.
　なお、インク循環装置８の一例として、水頭差によってインクの循環を制御する方法を説明したが、インクの循環流を発生できる構成であれば、当然適宜変更可能である。 As an example of the ink circulation device 8, the method of controlling the circulation of ink by using the difference in water head has been described, but it is naturally possible to make appropriate modifications as long as the configuration is capable of generating a circulating flow of ink.
［温度調整装置］
　上記ヘッドユニット２２４には、ノズル１１１に供給される吐出前のインクを加温して温度調節を行う温度調整部としての温度調整装置２２６を併設してもよい（図１５参照）。温度調整装置２２６は、温度制御が可能なヒーターと温度検出素子とを有する。ヒーターは、ノズル１１１よりも上流側のインク流路内又はタンク内のインクを加熱可能な位置に設けられる。温度検出素子は、ヒーター近傍又は当該ヒーターよりもノズル１１１近傍に設けられ、ノズル１１１に供給されるインクの温度を検出する。
　そして、ヒーターは、制御部２４０によって、温度検出素子の検出に基づいてインクが所定温度となるように出力制御が行われる。これにより、ノズル１１１から吐出される直前のインクを適正な目標温度に調整することができる。 [Temperature control device]
The head unit 224 may be provided with a temperature adjustment device 226 as a temperature adjustment section that heats and adjusts the temperature of the ink before ejection supplied to the nozzles 111 (see FIG. 15). The temperature adjustment device 226 has a temperature controllable heater and a temperature detection element. The heater is provided at a position that can heat the ink in the ink flow path or tank on the upstream side of the nozzle 111 . The temperature detection element is provided near the heater or nearer the nozzle 111 than the heater, and detects the temperature of the ink supplied to the nozzle 111 .
The output of the heater is controlled by the controller 240 so that the temperature of the ink reaches a predetermined temperature based on the detection of the temperature detection element. As a result, the ink immediately before being ejected from the nozzles 111 can be adjusted to the appropriate target temperature.
［ピニング装置］
　図１３はピニング装置３２０の斜視図である。
　ピニング装置３２０は、ヘッドユニット２２４と共にロボットアーム３１０の先端部に保持され、インクジェットヘッド１００から吐出されたインクに対してエネルギー線照射を行う照射装置からなる。ピニング装置３２０は、ロボットアーム３１０の先端部において、ヘッドユニット２２４に対する前側（図３において説明したインクジェットヘッド１００における「前側」）に配置されている。
　上記ピニング装置３２０は、例えば、赤外線光（特に、近赤外線：波長0.7～2.5[μm]程度）、紫外線光（波長10～400[nm]程度）、エキシマ発光等のエネルギー線をインクに照射する。
　ここでは、近赤外線を照射するピニング装置３２０を例示する。 [Pinning device]
FIG. 13 is a perspective view of the pinning device 320. FIG.
The pinning device 320 is held at the tip of the robot arm 310 together with the head unit 224 and consists of an irradiation device that irradiates ink ejected from the inkjet head 100 with energy rays. The pinning device 320 is arranged at the tip of the robot arm 310 on the front side of the head unit 224 (the “front side” in the inkjet head 100 described with reference to FIG. 3).
The pinning device 320 irradiates the ink with energy rays such as infrared light (especially, near-infrared light: wavelength of about 0.7 to 2.5 [μm]), ultraviolet light (wavelength of about 10 to 400 [nm]), and excimer emission. .
Here, a pinning device 320 that emits near-infrared rays is exemplified.
　ピニング装置３２０は、近赤外線を発光する複数のＬＥＤ(light emitting diode)３２１と、各ＬＥＤ３２１からの近赤外線光を所定の照射位置に集光する集光板３２２と、図示しない各ＬＥＤ３２１の発光回路とを備え、これらが筐体によって一体的にユニット化され、ヘッドユニット２２４と共にロボットアーム３１０の先端部に保持されている。 The pinning device 320 includes a plurality of LEDs (light emitting diodes) 321 that emit near-infrared light, a light collecting plate 322 that collects the near-infrared light from each LED 321 at a predetermined irradiation position, and a light emitting circuit (not shown) of each LED 321. , which are integrally unitized by a housing and held at the tip of the robot arm 310 together with the head unit 224 .
　図１４はヘッドユニット２２４のインクジェットヘッド１００によるインク吐出の目標位置とピニング装置３２０の集光板３２２による近赤外線の照射位置との関係を示す側面図である。この図はインクジェットヘッド１００における左右方向から見た状態を示している。
　ヘッドユニット２２４のインクジェットヘッド１００は、その吐出動作の原理的な制約により、設計条件に基づいてインクジェットヘッド１００のノズル面から目標の吐出位置までの適正な吐出距離ｄが一定の値に決まっている。従って、各ノズル１１１から前方に吐出距離ｄとなる位置を目標の吐出位置Ｐとして吐出が行われる。
　ピニング装置３２０の集光板３２２は、ヘッドユニット２２４の複数のインクジェットヘッド１００の全ノズル１１１から前方に吐出距離ｄとなる全ての吐出位置Ｐ及びその周辺を含むことが可能な範囲を照射可能となるように照射方向及び集光範囲が調整されている。 FIG. 14 is a side view showing the relationship between the target position of ink ejection by the inkjet head 100 of the head unit 224 and the irradiation position of the near-infrared rays by the light collecting plate 322 of the pinning device 320. As shown in FIG. This figure shows the state of the inkjet head 100 viewed from the left-right direction.
In the inkjet head 100 of the head unit 224, the appropriate ejection distance d from the nozzle surface of the inkjet head 100 to the target ejection position is determined to be a constant value based on the design conditions due to the principle restrictions of the ejection operation. . Therefore, ejection is performed with a target ejection position P set to a position that is the ejection distance d ahead of each nozzle 111 .
The light-condensing plate 322 of the pinning device 320 can irradiate a range that can include all the ejection positions P that are the ejection distance d forward from all the nozzles 111 of the plurality of inkjet heads 100 of the head unit 224 and their surroundings. The irradiation direction and the light collection range are adjusted as follows.
　なお、ピニング装置３２０により、紫外線光を照射する場合には、光源として紫外線ランプや紫外線ＬＥＤが搭載され、エキシマ発光を照射する場合には、光源としてエキシマランプが搭載される。また、これらの場合も、上記インクジェットヘッド１００の全ノズル１１１の吐出位置Ｐに集光するための集光板を設けることが好ましい。 When the pinning device 320 emits ultraviolet light, an ultraviolet lamp or an ultraviolet LED is mounted as a light source, and when excimer light emission is emitted, an excimer lamp is mounted as a light source. Also in these cases, it is preferable to provide a condensing plate for condensing light onto the ejection positions P of all the nozzles 111 of the inkjet head 100 .
　ピニング装置３２０は、ヘッドユニット２２４の全てのノズル１１１から吐出されるインクの吐出位置Ｐを含むようにエネルギー線の照射を行うことにより、吐出されて被描画体となるワークＷの表面に付着したインクのドットに対して加熱乾燥或いは硬化による粘度向上（ピニング効果の付与）を図り、ワークＷの表面が水平上向きではない場合（傾斜状態や下向き状態）でも、インクの液だれを抑制することができる。 The pinning device 320 irradiates the energy beams so as to include the ejection positions P of the ink ejected from all the nozzles 111 of the head unit 224, so that the energy rays are ejected and attached to the surface of the work W, which is the object to be drawn. By improving the viscosity (imparting the pinning effect) of the ink dots by heat drying or curing, even when the surface of the work W is not horizontally upward (inclined state or downward state), it is possible to suppress ink dripping. can.
　なお、ピニング装置３２０は、各種のエネルギー線の照射装置である場合に限られず、吐出されたインクを加熱する加熱装置であってもよい。その場合、加熱装置は、インクを加熱する熱源となるヒーター素子と、ヒーター素子で加熱された高温空気をインクの付着位置に吹き付けるファン等の送風手段とを備える構成とすることが好ましい。この場合も、ワークＷの表面上に付着したインクに対して集中的に高温空気を当てることができ、迅速な乾燥によりインクを効果的に固着させることが可能となる。 It should be noted that the pinning device 320 is not limited to various energy beam irradiation devices, and may be a heating device that heats the ejected ink. In this case, the heating device preferably includes a heater element serving as a heat source for heating the ink, and blowing means such as a fan for blowing high-temperature air heated by the heater element to the ink adhesion position. Also in this case, high-temperature air can be intensively applied to the ink adhering to the surface of the work W, and the ink can be effectively fixed by rapid drying.
［測距装置］
　また、描画装置３００は、ヘッドユニット２２４及びピニング装置３２０と共に、ロボットアーム３１０の先端部に測距装置２２５を備える構成としてもよい。
　測距装置２２５は、ヘッドユニット２２４の各ノズル１１１から前方のワークＷの表面までの距離を検出する検出装置、例えば、LiDAR(Laser Imaging Detection and Ranging)のような二次元又は三次元計測装置である。この測距装置２２５により、各ノズル１１１から前方のワークＷの表面までの距離を前述した適正な吐出距離ｄに維持して吐出を行うようにロボットアーム３１０の制御を行うことができる。
　なお、描画装置３００において、測距装置２２５は、必須の構成ではない。例えば、ワークＷの表面形状の三次元データが取得され、ロボットアーム３１０の座標系にワークＷの表面の座標が展開可能である場合には、ワークＷの表面位置座標に基づいて各ノズル１１１からワークＷの表面までの距離が適正な吐出距離ｄを維持するように制御することで測距装置２２５を不要とすることができる。なお、ロボットアーム３１０の座標系に展開されたワークＷの表面の座標と測距装置２２５の検出によるワークＷの表面の距離とを照合して、両方を利用してロボットアーム３１０を制御してもよい。 [Range finder]
Further, the drawing apparatus 300 may be configured to include a distance measuring device 225 at the tip of the robot arm 310 together with the head unit 224 and the pinning device 320 .
The distance measurement device 225 is a detection device that detects the distance from each nozzle 111 of the head unit 224 to the surface of the workpiece W in front, for example, a two-dimensional or three-dimensional measurement device such as LiDAR (Laser Imaging Detection and Ranging). be. With this distance measuring device 225, the robot arm 310 can be controlled so that the distance from each nozzle 111 to the front surface of the workpiece W is maintained at the above-described appropriate discharge distance d.
Note that the distance measuring device 225 is not an essential component in the rendering device 300 . For example, when the three-dimensional data of the surface shape of the workpiece W is acquired and the coordinates of the surface of the workpiece W can be developed in the coordinate system of the robot arm 310, each nozzle 111 outputs the workpiece W based on the surface position coordinates of the workpiece W. The distance measuring device 225 can be made unnecessary by controlling the distance to the surface of the work W so as to maintain an appropriate ejection distance d. The coordinates of the surface of the work W developed in the coordinate system of the robot arm 310 and the distance of the surface of the work W detected by the distance measuring device 225 are collated, and both are used to control the robot arm 310. good too.
［インク］
　インクジェットヘッド１００に用いられるインクは、インクジェットヘッドから吐出できれば特に制限はないが、安定な射出特性を得る観点から、せん断速度１０００［１／ｓ］時の粘度（２５℃）が２００ｍＰａ・ｓ以下となるチキソ性を有するインクであることが好ましい。
　さらに、良好な射出特性の観点から、せん断速度１０００［１／ｓ］時の粘度が、２～１００ｍPa・ｓであることがより好ましく、５～１５ｍPa・ｓであることが更に好ましい。
　また、インクは、せん断速度１００［１／ｓ］時の粘度がせん断速度１０００［１／ｓ］時の粘度よりも大きく、せん断速度１０［１／ｓ］時の粘度がせん断速度１００［１／ｓ］時の粘度よりも大きくなることが、チキソ性を有することから好ましく、チキソ性を有することで吐出後に増粘することで液垂れを防止できる。 [ink]
The ink used in the inkjet head 100 is not particularly limited as long as it can be ejected from the inkjet head, but from the viewpoint of obtaining stable ejection characteristics, the viscosity (25° C.) at a shear rate of 1000 [1/s] should be 200 mPa·s or less. It is preferable that the ink has a thixotropic property.
Furthermore, from the viewpoint of good injection properties, the viscosity at a shear rate of 1000 [1/s] is more preferably 2 to 100 mPa·s, and even more preferably 5 to 15 mPa·s.
In addition, the viscosity of the ink at a shear rate of 100 [1/s] is greater than the viscosity at a shear rate of 1000 [1/s], and the viscosity at a shear rate of 10 [1/s] is 100 [1/s]. It is preferable that the viscosity is greater than the viscosity at the time of s] because it has thixotropic properties, and the thixotropic properties increase the viscosity after ejection, thereby preventing liquid dripping.
　上記インクとしては、水系溶媒（水溶性溶媒、水）、顔料及び定着樹脂を含有することが好ましく、特に、チキソ性付与剤を含有することが好ましい。
　また、インクは、顔料が、３～１０質量％の範囲内で、定着樹脂が、８～２０質量％の範囲内で、水溶性溶媒が、１０～３０質量％の範囲内であり、かつ、水が、４０～７９質量％の範囲内で含有することが好ましい。 The ink preferably contains an aqueous solvent (water-soluble solvent, water), a pigment and a fixing resin, and more preferably contains a thixotropic agent.
The ink contains a pigment in the range of 3 to 10% by mass, a fixing resin in the range of 8 to 20% by mass, and a water-soluble solvent in the range of 10 to 30% by mass, and It is preferable that water is contained within the range of 40 to 79% by mass.
　また、本発明に係るインクは、固形分の含有量が６～３０質量％であることが好ましい。「インクの固形分」とは、１００℃の乾燥でインクから除去できない固体状成分をいう。インクの固形分は、例えば、水系溶媒を含む溶媒以外の成分である。 Further, the ink according to the present invention preferably has a solid content of 6 to 30% by mass. "Ink solids" refers to solid components that cannot be removed from the ink by drying at 100°C. The solid content of the ink is, for example, components other than the solvent including the aqueous solvent.
　また、上記インクは、前記した水系溶媒、顔料、定着樹脂及びチキソ性付与剤以外に、チキソ性に関する上記の特性を損なわない任意の成分を含有できる。任意成分としては、例えば、顔料分散剤、界面活性剤等が挙げられる。チキソ性を有するインクにおける各成分について以下に説明する。 In addition, the ink may contain any component that does not impair the above-described properties relating to thixotropy, in addition to the aqueous solvent, pigment, fixing resin, and thixotropy-imparting agent. Examples of optional components include pigment dispersants and surfactants. Each component in the thixotropic ink will be described below.
　（チキソ性付与剤）
　チキソ性付与剤は、前述した粘度特性の条件を満足するチキソ性を付与できる材料であれば特に制限されない。
　チキソ性付与剤は、粒子形状（ただし、粒子形状は繊維形状を含む。）であることが好ましく、アスペクト比が２０以上であることがより好ましい。 (Thixotropic agent)
The thixotropy-imparting agent is not particularly limited as long as it is a material capable of imparting thixotropy that satisfies the conditions of the viscosity characteristics described above.
The thixotropy-imparting agent preferably has a particle shape (however, the particle shape includes a fiber shape), and more preferably has an aspect ratio of 20 or more.
　チキソ性付与剤が粒子形状である場合の形状としては、楕円状、鱗片状、板状、針状、繊維状等が好ましい。チキソ性付与剤の短径に対する長径の比を示すアスペクト比は、２０以上であることが好ましい。アスペクト比が２０以上であると、インクによりチキソ性を付与しやすい。なお、チキソ性付与剤の長径は２μｍ以下が好ましい。チキソ性付与剤の長径が２μｍを超えるとインクジェット吐出性に影響を及ぼす場合がある。 When the thixotropy-imparting agent is in the form of particles, the shape is preferably elliptical, scale-like, plate-like, needle-like, fiber-like, or the like. The aspect ratio indicating the ratio of the major axis to the minor axis of the thixotropic agent is preferably 20 or more. When the aspect ratio is 20 or more, it is easier to impart thixotropy to the ink. The long diameter of the thixotropy-imparting agent is preferably 2 μm or less. If the major axis of the thixotropy-imparting agent exceeds 2 μm, it may affect the ink-jet dischargeability.
　なお、本明細書において、チキソ性付与剤のアスペクト比の測定断面は、粒子の長さ方向に平行する断面であって厚さ方向に切った断面である。アスペクト比は、該断面から得られる各５０個の平均粒子長径と平均粒子短径から求めた値である。ここで、粒子形状が、鱗片状、板状の場合、短径は粒子の厚さであり、長径は粒子の厚さ方向に直交する断面の、言い換えれば粒子を平面視した場合の、長辺の長さ又は最大径である。粒子形状が、針状、繊維状の場合、長径は粒子の長さであり、短径は粒子の長さ方向に直交する断面の、言い換えれば粒子を平面視した場合の、長径又は最大幅である。 In the present specification, the cross section for measuring the aspect ratio of the thixotropy-imparting agent is a cross section parallel to the length direction of the particle and cut in the thickness direction. The aspect ratio is a value determined from the average major particle diameter and average minor diameter of 50 particles obtained from the cross section. Here, when the particle shape is scaly or plate-like, the short axis is the thickness of the particle, and the long axis is the long side of the cross section perpendicular to the thickness direction of the particle, in other words, when the particle is viewed from above. is the length or maximum diameter of When the particle shape is acicular or fibrous, the major axis is the length of the particle, and the minor axis is the major axis or maximum width of the cross section perpendicular to the length direction of the particle, in other words, when the particle is viewed from above. be.
　チキソ性付与剤の材質としては、多糖類、無機粒子等が挙げられる。多糖類として、具体的には、セルロース、キチン、キトサン、キサンタンガム、ウェランガム、サクシノグリカン、グアーガム、ローカストビーンガム及びその誘導体、グリコマンナン、寒天、カラギーナン等が挙げられる。上記誘導体としては、例えば、セルロースの誘導体として、メチルセルロース、ヒドロキシエチルセルロース、カルボキシメチルセルロース等が挙げられる。 Materials for the thixotropic agent include polysaccharides and inorganic particles. Specific examples of polysaccharides include cellulose, chitin, chitosan, xanthan gum, welan gum, succinoglycan, guar gum, locust bean gum and derivatives thereof, glycomannan, agar, and carrageenan. Examples of the derivatives include cellulose derivatives such as methyl cellulose, hydroxyethyl cellulose, and carboxymethyl cellulose.
　多糖類としては、重量平均分子量が数百万程度の天然多糖類が好ましい。具体的には、キサンタンガム、グアーガム、及びカラギーナン等が好ましい。 As polysaccharides, natural polysaccharides with a weight average molecular weight of about several million are preferable. Specifically, xanthan gum, guar gum, carrageenan, and the like are preferred.
　また、上記インクにおいてはチキソ性付与剤として、樹木、蟹、海老等の甲殻類の殻等の、多糖類の集合体を、触媒を用いる酸化処理、グラインダー等を用いる機械処理等の従来公知の方法で繊維を極めて細かく解して微細化した多糖類のナノファイバーが好ましく用いられる。多糖類のナノファイバーにおける多糖類としては、セルロース、キチン及びキトサンのうち少なくとも一つであることが好ましく、セルロースがより好ましい。 In the above ink, as a thixotropy-imparting agent, aggregates of polysaccharides such as shells of crustaceans such as trees, crabs, and shrimps are subjected to oxidation treatment using a catalyst, mechanical treatment using a grinder, and the like. Polysaccharide nanofibers are preferably used, which are finely pulverized by dissolving the fibers extremely finely. The polysaccharide in the polysaccharide nanofiber is preferably at least one of cellulose, chitin and chitosan, and more preferably cellulose.
　なお、本明細書において、ナノファイバーは、幅が１～１００ｎｍ程度であって、アスペクト比が１００以上のものをいう。ナノファイバーの長さ及び幅は、例えば、電子顕微鏡を用いて測定することができる。ナノファイバーの幅は、例えば、平面視における幅を測定してもよく、ナノファイバーの長さ方向に直交する断面の直径を幅として測定してもよい。いずれの場合も、５０個のナノファイバーにおいて、各ナノファイバーにおける最大幅の平均をナノファイバーの「幅」とする。ナノファイバーの「長さ」は、５０個のナノファイバーの平均長さである。ナノファイバーのアスペクト比は、該長さを該幅で除した値として求められる。 In this specification, nanofibers refer to those having a width of about 1 to 100 nm and an aspect ratio of 100 or more. The length and width of nanofibers can be measured, for example, using electron microscopy. The width of the nanofiber may be measured, for example, as the width in plan view, or as the diameter of the cross section perpendicular to the longitudinal direction of the nanofiber. In either case, the "width" of the nanofiber is the average of the maximum widths of each nanofiber in the 50 nanofibers. The "length" of a nanofiber is the average length of 50 nanofibers. The aspect ratio of a nanofiber is determined as the length divided by the width.
　上記インクにおいて、チキソ性付与剤として、多糖類のナノファイバーを用いる場合、ナノファイバーのうちでもより小さいサイズのものが好ましい。ナノファイバーの幅は、好ましくは１～５０ｎｍであり、より好ましくは１～５ｎｍである。また、ナノファイバーの長さは、好ましくは０．５～２μｍであり、より好ましくは０．５～１μｍであるが、これに限定されない。ナノファイバーのアスペクト比は、２０～４００の範囲内にあるのがより好ましく、１００～３００の範囲内がさらに好ましい。 In the above ink, when polysaccharide nanofibers are used as the thixotropy-imparting agent, nanofibers with a smaller size are preferred. The width of the nanofibers is preferably 1-50 nm, more preferably 1-5 nm. Moreover, the length of the nanofiber is preferably 0.5 to 2 μm, more preferably 0.5 to 1 μm, but is not limited thereto. The aspect ratio of the nanofibers is more preferably in the range of 20-400, more preferably in the range of 100-300.
　多糖類の集合体では、セルロース、キチン、キトサン等の多糖類は、ミクロフィブリルと呼ばれる構造単位が互いに結束した状態で存在している。このミクロフィブリルは、幅が３～４ｎｍ、長さが数μｍ（例えば、２～５μｍ）であるが、１本１本ほどくことは困難である。多糖類の集合体を機械的に破砕する場合、多くの従来法では、幅が２０～５０ｎｍ程度のナノファイバーとなる。本実施形態においては多糖類のナノファイバーとして、このようなナノファイバーを用いてもよいが、ＴＥＭＰＯ酸化によりより細かく例えばミクロフィブリル単位に解かれたＴＥＭＰＯ酸化ナノファイバーを用いることがより好ましい。 In polysaccharide aggregates, polysaccharides such as cellulose, chitin, and chitosan exist in a state in which structural units called microfibrils are bound together. These microfibrils have a width of 3 to 4 nm and a length of several μm (for example, 2 to 5 μm), but it is difficult to untie them one by one. In the case of mechanical crushing of polysaccharide aggregates, nanofibers with a width of about 20 to 50 nm are obtained in many conventional methods. In the present embodiment, such nanofibers may be used as the polysaccharide nanofibers, but it is more preferable to use TEMPO-oxidized nanofibers that have been broken into finer, for example, microfibril units by TEMPO oxidation.
　「ＴＥＭＰＯ酸化」とは、２，２，６，６－テトラメチル－１－ピペリジン－オキシラジカル（ＴＥＭＰＯ）を触媒とする酸化反応である。多糖類の集合体をＴＥＭＰＯの存在下で酸化することで、ミクロフィブリルに相当する、例えば、幅が３～４ｎｍ、長さが数μｍ（例えば、２～５μｍ）の極めて細かいナノファイバーが得られる。 "TEMPO oxidation" is an oxidation reaction catalyzed by 2,2,6,6-tetramethyl-1-piperidine-oxy radical (TEMPO). Oxidation of polysaccharide aggregates in the presence of TEMPO yields extremely fine nanofibers corresponding to microfibrils, for example, 3-4 nm wide and several μm long (eg, 2-5 μm). .
　チキソ性付与剤として用いられるセルロースナノファイバーは、セルロースをナノファイバー化したものである。ナノファイバー化されたセルロースの形態としては、例えば、粉末セルロース、微結晶セルロース等が挙げられる。 The cellulose nanofiber used as a thixotropic agent is cellulose nanofiber. Examples of forms of nanofiber cellulose include powdered cellulose and microcrystalline cellulose.
　セルロースナノファイバーとしては、第一工業製薬社製のレオクリスタ（登録商標）、日本製紙社製のＴＥＭＰＯ酸化セルロースナノファイバー、セレンピアＴＣ－０１Ａ、セレンピアＴＣ－０２Ｘ（「セレンピア」は登録商標）、スギノマシン社製ＩＭａ－１０００２、ＢＭａ－１０００２、ＷＭａ－１０００２、ＡＭａ－１０００２、ＦＭａ－１０００２、大王製紙社製のＥＬＥＸ－☆、ＥＬＥＸ－Ｓ、王子製紙社製アウロ・ヴィスコ等を好適に利用可能である。 Cellulose nanofibers include Rheocrysta (registered trademark) manufactured by Daiichi Kogyo Seiyaku Co., Ltd., TEMPO oxidized cellulose nanofiber manufactured by Nippon Paper Industries Co., Ltd., Celenpia TC-01A, Celenpia TC-02X ("Celempia" is a registered trademark), and Sugino Machine. IMa-10002, BMa-10002, WMa-10002, AMa-10002, FMa-10002 manufactured by Co., Ltd., ELEX-☆, ELEX-S manufactured by Daio Paper Co., Ltd., Auro Visco manufactured by Oji Paper Co., etc. can be suitably used. .
　無機粒子としては、インクにチキソ性に関して前述した条件を満足するチキソ性を付与できる材料及び形状を有する粒子であれば制限されないが、天然又は合成の各種粘土鉱物の粒子が好ましい。 The inorganic particles are not limited as long as they are particles having a material and a shape that can impart thixotropy to the ink that satisfies the conditions described above regarding thixotropy, but particles of various natural or synthetic clay minerals are preferable.
　粘土鉱物としては、スメクタイト粘土鉱物が好ましい。スメクタイト粘土鉱物は、層状ケイ酸塩鉱物又はベントナイト石群鉱物のフィロシリケート類に分類される。スメクタイト粘土鉱物は、積層構造により、モンモリロナイト亜群及びサポナイト亜群に分類される。モンモリロナイト亜群は、モンモリロナイト、ノントロナイト又はバイデライトを含む。サポナイト亜群は、ヘクトライト、サポナイト又はソーコナイトを含む。 A smectite clay mineral is preferable as the clay mineral. Smectite clay minerals are classified in the phyllosilicate class of layered silicate minerals or bentonite group minerals. Smectite clay minerals are classified into the montmorillonite subgroup and the saponite subgroup according to their layered structure. The montmorillonite subgroup includes montmorillonite, nontronite or beidellite. The saponite subgroup includes hectorite, saponite or sauconite.
　スメクタイト粘土鉱物は天然物であっても合成物であってもよい。スメクタイト粘土鉱物は板状体が積層された層状物質であって、チキソ性付与剤として用いる場合、通常、層間剥離された板状の粒子として用いられる。スメクタイト粘土鉱物が合成物の場合、天然物と比べて小さいアスペクト比を有するとともに、不純物含有量が少ない。 The smectite clay mineral may be either natural or synthetic. A smectite clay mineral is a layered substance in which plate-like bodies are laminated, and when used as a thixotropy-imparting agent, it is usually used as plate-like particles separated between layers. Synthetic smectite clay minerals have a smaller aspect ratio and less impurity content than natural ones.
　スメクタイト粘土鉱物の板状粒子は、厚さが０．２～３．０ｎｍの範囲内にあり、長さが１０～１５０ｎｍの範囲内にあるのが好ましい。板状粒子は、厚さが０．２～２．０ｎｍの範囲内にあり、長さが１０～１２５ｎｍの範囲内にあるのがより好ましい。アスペクト比は、板状粒子の長さを厚さで除した値であり、２０以上であることが好ましい。アスペクト比は、２０～２００の範囲内にあるのがより好ましい。 The plate-like particles of the smectite clay mineral preferably have a thickness in the range of 0.2 to 3.0 nm and a length in the range of 10 to 150 nm. More preferably, the platelet-like particles have a thickness in the range of 0.2-2.0 nm and a length in the range of 10-125 nm. The aspect ratio is a value obtained by dividing the length of the plate-like particles by the thickness, and is preferably 20 or more. More preferably, the aspect ratio is in the range of 20-200.
　板状粒子の長さ及び厚さは、例えば、電子顕微鏡を用いて測定することができる。板状粒子の厚さは、例えば、所定の断面で測定される板状粒子の厚さの５０個の平均値である。板状粒子の「長さ」は、板状粒子を平面視したときに最大径として測定される長さの５０個の平均値である。板状粒子のアスペクト比は、該長さを該厚さで除した値として求められる。 The length and thickness of plate-like particles can be measured, for example, using an electron microscope. The thickness of the plate-like particles is, for example, the average value of 50 thicknesses of the plate-like particles measured on a given cross section. The “length” of the plate-like particles is the average value of 50 lengths measured as the maximum diameter when the plate-like particles are viewed in plan. The aspect ratio of plate-like particles is determined as a value obtained by dividing the length by the thickness.
　スメクタイト粘土鉱物として、例えば、合成層状ケイ酸塩であるラポナイト（ビッグケミー社製）が使用できる。ラポナイトは、構造及び化学組成が天然スメクタイト粘土鉱物であるヘクトライトに近い合成低電荷粘土である。ラポナイトの主な粒子は、最大径が３０ｎｍ及び厚さが１ｎｍの円盤状の形態である。 As the smectite clay mineral, for example, Laponite (manufactured by Big Chemie), which is a synthetic layered silicate, can be used. Laponite is a synthetic low charge clay that is close in structure and chemical composition to the natural smectite clay mineral hectorite. The main particles of Laponite are disc-shaped with a maximum diameter of 30 nm and a thickness of 1 nm.
　スメクタイト粘土鉱物として、市販品を用いてもよい。市販品としては、例えば、ラポナイトＲＤ（ビッグケミー社製）、クニミエ工業（株）製の精製ベントナイトであるクニピアＦ、クニピアＧ等が挙げられる。 A commercially available product may be used as the smectite clay mineral. Examples of commercially available products include Laponite RD (manufactured by Big Chemie), Kunipia F and Kunipia G, which are purified bentonites manufactured by Kunimie Kogyo Co., Ltd., and the like.
　また、無機粒子として、ナノファイバーである、川研ファインケミカル製のアルミナナノファイバー（短径が４ｎｍで長径が１４００ｎｍ）を用いてもよい。 As the inorganic particles, alumina nanofibers manufactured by Kawaken Fine Chemicals Co., Ltd. (with a short diameter of 4 nm and a long diameter of 1400 nm), which are nanofibers, may be used.
　本実施形態に係るインクにおけるチキソ性付与剤の含有量は、インク全量に対して０．０１～１質量％の範囲内であることが好ましく、０．０８～０．５質量％の範囲内であることがより好ましい。 The content of the thixotropy-imparting agent in the ink according to the present embodiment is preferably in the range of 0.01 to 1% by mass with respect to the total amount of the ink, and is in the range of 0.08 to 0.5% by mass. It is more preferable to have
　本実施形態に係るインクにおいて、チキソ性付与剤は１種を単独で用いてもよく、２種以上を併用してもよい。なお、本実施形態に係るインクにおいて、チキソ性付与剤は２種以上の材料からなることが好ましい。さらに、該２種以上の材料のうちの１種はスメクタイト粘土鉱物であることが好ましい。チキソ性付与剤の好ましい組み合わせとして、セルロースナノファイバーとスメクタイト粘土鉱物の組み合わせ、キサンタンガムとスメクタイト粘土鉱物の組み合わせが挙げられる。特に、セルロースナノファイバーとスメクタイト粘土鉱物の組み合わせが好ましい。 In the ink according to the present embodiment, the thixotropy-imparting agents may be used singly or in combination of two or more. In addition, in the ink according to the present embodiment, the thixotropy-imparting agent is preferably composed of two or more materials. Furthermore, one of the two or more materials is preferably a smectite clay mineral. Preferred combinations of thixotropic agents include a combination of cellulose nanofibers and smectite clay minerals, and a combination of xanthan gum and smectite clay minerals. A combination of cellulose nanofibers and smectite clay minerals is particularly preferred.
　セルロースナノファイバーとスメクタイト粘土鉱物は、それぞれ単独で用いた場合であっても、例えば、インク乾燥率２０％で、特異的なゲル構造体を形成することで、インクに弾性的な性質を付与することができると考えられる。また、セルロースナノファイバー及びスメクタイト粘土鉱物を組み合わせて用いることで、上記の弾性的な性質がより高められ、好ましい。 Cellulose nanofibers and smectite clay minerals, even when used alone, form a specific gel structure at an ink drying rate of 20%, for example, to impart elastic properties to the ink. It is considered possible. Moreover, by using a combination of cellulose nanofibers and smectite clay minerals, the above elastic properties are further enhanced, which is preferable.
　スメクタイト粘土鉱物とその他のチキソ性付与剤の比はインク粘度やチキソ性に応じて選択できるが、比率としてはスメクタイト粘土鉱物：その他のチキソ性付与剤が、質量比で、１０：１～１：１０の範囲で調整できる。組み合わせることによりそれぞれを単体で添加するよりもインクのチキソ性が大きく向上して画質が良くなる。チキソ性が向上する理由は推定だが、スメクタイト粘土鉱物は電荷を持っており、スメクタイト粘土鉱物とその他のチキソ性付与剤が電気的に会合して構造体を形成していることが考えられる。 The ratio of the smectite clay mineral and the other thixotropic agent can be selected according to the ink viscosity and the thixotropic property. It can be adjusted in a range of 10. By combining them, the thixotropy of the ink is greatly improved and the image quality is improved as compared with the addition of each of them alone. The reason why the thixotropy is improved is presumed, but it is conceivable that the smectite clay mineral has an electric charge, and the smectite clay mineral and other thixotropy-imparting agents are electrically associated to form a structure.
　（顔料）
　本発明に係るインクに含有される顔料としては、従来公知の有機及び無機顔料が使用できる。 (pigment)
Conventionally known organic and inorganic pigments can be used as the pigment contained in the ink according to the present invention.
　（顔料分散剤）
　本実施形態に係るインクは、顔料を分散させるために任意に顔料分散剤を含有する。顔料分散剤としては、格別限定されないがアニオン性基を有する高分子分散剤が好ましく、数平均分子量が５０００～２０００００の範囲内のものを好適に用いることができる。 (Pigment dispersant)
The ink according to this embodiment optionally contains a pigment dispersant to disperse the pigment. The pigment dispersant is not particularly limited, but a polymer dispersant having an anionic group is preferable, and one having a number average molecular weight within the range of 5,000 to 200,000 can be suitably used.
　（水系溶媒）
　本実施形態に係るインクは、水系溶媒を含有する。水系溶媒は、水を必須の溶媒として含有し、粘度調整などのために、好ましくは、任意に公知の水溶性溶媒を含む。 (Aqueous solvent)
The ink according to this embodiment contains an aqueous solvent. The aqueous solvent contains water as an essential solvent, and preferably optionally contains a known water-soluble solvent for viscosity adjustment and the like.
　（定着樹脂）
　本実施形態に係るインクは任意に定着樹脂を含有する。定着樹脂は、着色剤である顔料のバインダーとして機能し、被描画体への塗膜の接着性を向上させ、かつインクを用いて得られる塗膜の耐擦性を向上させる機能を有する。定着樹脂は、水不溶性樹脂であることが好ましい。定着樹脂としての水不溶性樹脂は、水系溶媒中に分散した微粒子の状態で用いられることが好ましい。 (fixing resin)
The ink according to this embodiment optionally contains a fixing resin. The fixing resin functions as a binder for the pigment, which is the colorant, to improve the adhesion of the coating film to the object to be drawn, and to improve the abrasion resistance of the coating film obtained using the ink. The fixing resin is preferably a water-insoluble resin. The water-insoluble resin as the fixing resin is preferably used in the form of fine particles dispersed in an aqueous solvent.
　（界面活性剤）
　インクは任意に界面活性剤を含有することができる。これにより、インクの出射安定性の向上や、被描画体に着弾した液滴の広がり（ドット径）を制御することができる。
　界面活性剤は、本発明の効果を損なうことのない範囲であれば、特に制限なく用いることができる。 (Surfactant)
The ink can optionally contain surfactants. As a result, it is possible to improve the ejection stability of the ink and to control the spread (dot diameter) of droplets that have landed on the object to be drawn.
Surfactants can be used without any particular limitation as long as they do not impair the effects of the present invention.
　（その他の添加剤）
　上記インクには、上記説明した以外に、本発明の効果を損なうことのない範囲で必要に応じて、出射安定性、保存安定性、画像保存性、その他の諸性能向上の目的に応じて、公知の各種添加剤、例えば、粘度調整剤、比抵抗調整剤、皮膜形成剤、紫外線吸収剤、酸化防止剤、退色防止剤、防ばい剤、防錆剤等を適宜選択して用いることができる。 (Other additives)
In addition to the above-described inks, the above-described inks may contain, as necessary, in accordance with the purpose of improving emission stability, storage stability, image storage stability, and other various performances within a range that does not impair the effects of the present invention. Various known additives such as viscosity modifiers, resistivity modifiers, film-forming agents, ultraviolet absorbers, antioxidants, anti-fading agents, anti-mold agents, anti-rust agents, etc. can be appropriately selected and used. .
　インクの調製は、上記各成分を上記含有量となるようにして混合することで行う。好ましくは、顔料は顔料分散剤により水系溶媒の一部に分散された分散液として、他の成分と混合することが好ましい。定着樹脂を含有する場合、定着樹脂は、必要に応じて添加される界面活性剤を用いて、水系溶媒の一部に分散された分散液として、他の成分と混合することが好ましい。 The ink is prepared by mixing each of the above components so that the content is the above. Preferably, the pigment is dispersed in a portion of the aqueous solvent with a pigment dispersant and mixed with other components as a dispersion. When a fixing resin is contained, the fixing resin is preferably mixed with other components as a dispersion in a portion of the aqueous solvent using a surfactant added as necessary.
［ゲル化剤を含有するインクについて］
　さらに、インクは、ゲル化剤を含有するものであってもよい。
　ゲル化剤を含有するインクとしては、国際公開WO2021/001937A1の段落００２７～００５５に記載に詳細が記載されており、これを適用することができる。 [Ink containing a gelling agent]
Furthermore, the ink may contain a gelling agent.
Ink containing a gelling agent is described in detail in paragraphs 0027 to 0055 of International Publication WO2021/001937A1, which can be applied.
［紫外線硬化剤を含有するインクについて］
　さらに、インクは、紫外線硬化剤を含有するものであってもよい。
　紫外線硬化剤を含有するインクとしては、特開2020-172043号公報の段落００６７～０１２９に記載に詳細が記載されており、これを適用することができる。 [Ink containing UV curing agent]
Furthermore, the ink may contain an ultraviolet curing agent.
Ink containing an ultraviolet curing agent is described in detail in paragraphs 0067 to 0129 of JP-A-2020-172043, and this can be applied.
　また、紫外線硬化剤を含有するインクにあっては、さらに、紫外線吸収剤を含有してもよい。紫外線吸収剤としては、特に限定されないが、例えば、特開昭５７－７４１９３号公報、同５７－８７９８８号公報及び同６２－２６１４７６号公報に記載のものを適用することができる。 Ink containing an ultraviolet curing agent may further contain an ultraviolet absorber. Although the ultraviolet absorber is not particularly limited, for example, those described in JP-A-57-74193, JP-A-57-87988 and JP-A-62-261476 can be applied.
［描画装置の主要な機能構成］
　図１５は、描画装置３００の主要な機能構成を示すブロック図である。
　描画装置３００は、上述したように、ロボットアーム３１０、ヘッドユニット２２４、ピニング装置３２０、インク循環装置８、測距装置２２５、温度調整装置２２６及び制御部２４０等を備える。 [Main functional configuration of drawing device]
FIG. 15 is a block diagram showing the main functional configuration of the rendering device 300. As shown in FIG.
The drawing device 300 includes the robot arm 310, the head unit 224, the pinning device 320, the ink circulation device 8, the distance measuring device 225, the temperature adjustment device 226, the control section 240, and the like, as described above.
　制御部２４０は、描画装置３００を構成する上記各構成と接続されており、これらの構成を制御する。制御部２４０は、ＣＰＵ、ＲＡＭ及びＲＯＭ（図示略）等を有する。ＣＰＵは、ＲＯＭ等の記憶装置から処理内容に応じた各種のプログラムやデータ等を読み出して実行し、実行された処理内容に応じて描画装置３００の各部の動作を制御する。ＲＡＭは、ＣＰＵにより処理される各種のプログラムやデータ等を一時的に記憶する。ＲＯＭは、ＣＰＵ等により読み出される各種のプログラムやデータ等を記憶する。 The control unit 240 is connected to each of the above components that make up the drawing apparatus 300, and controls these components. The control unit 240 has a CPU, RAM, ROM (not shown), and the like. The CPU reads and executes various programs, data, and the like according to the content of processing from a storage device such as a ROM, and controls the operation of each unit of the rendering device 300 according to the content of the executed processing. The RAM temporarily stores various programs and data processed by the CPU. The ROM stores various programs, data, and the like read by the CPU and the like.
　例えば、制御部２４０は、ワークＷに対する描画を実行するための基本的な制御として、予め用意されたワークＷの表面形状及び描画を行う範囲を定めた三次元データ又は測距装置２２５の検出によって得られたワークＷの表面形状及び描画を行う範囲の三次元データに基づいて、当該描画を行う範囲に描画を行う動作制御が実行される。
　即ち、ヘッドユニット２２４の各ノズル１１１からのインクの吐出及びピニング装置３２０による近赤外線の照射を行いつつ、インクジェットヘッド１００における前方又は後方への走査（ヘッドユニット２２４の搬送）が行われるようにロボットアーム３１０の動作制御が実行される。ヘッドユニット２２４の走査は、左右方向にヘッドユニット２２４の位置を変えつつ繰り返し行ってもよい。 For example, the control unit 240 performs three-dimensional data prepared in advance defining the surface shape of the work W and the drawing range, or the detection of the distance measuring device 225 as basic control for executing drawing on the work W. Based on the obtained three-dimensional data of the surface shape of the workpiece W and the area to be drawn, motion control for drawing is executed in the area to be drawn.
In other words, while ejecting ink from each nozzle 111 of the head unit 224 and irradiating near-infrared rays by the pinning device 320, the robot is moved so that the inkjet head 100 can be scanned forward or backward (conveyance of the head unit 224). Motion control of the arm 310 is executed. The scanning of the head unit 224 may be repeated while changing the position of the head unit 224 in the horizontal direction.
　また、他の基本的な制御として、制御部２４０は、描画装置３００のインク循環装置８に対して、次のような処理を行う。
　すなわち、制御部２４０は、ノズル１１１に連通する流路Ｒの平均せん断速度が１０００～１００００［１／ｓ］の範囲で予め設定されたせん断速度になるように、ノズル１１１に連通する流路Ｒを流れるインク流量（循環流量Ｑ）、すなわち循環差圧ΔＰを制御することが挙げられる。例えば、インク循環量は、30～300[ml/min]の範囲とする。
　例えば、各サブタンク８１，８２の液面高さを検出する液面センサを設け、ポンプ８８，８９の作動によりタンク８１，８２の液面高さを適宜調整して、圧力Ｐ１及び圧力Ｐ２が目標のインク流量（循環流量Ｑ）となるように制御する。その際、インク流路８６の途中には、バッファとなるインクの予備タンクを設けてもよい。
　また、インク循環装置８のポンプ８８に加えられる圧力や、各サブタンク８１，８２内のインク充填量と、アクチュエーターにより各サブタンク８１，８２の上下方向（重力方向）の位置とを適宜変更することによって圧力Ｐ１及び圧力Ｐ２を調整し、圧力Ｐ１及び圧力Ｐ２の圧力差（循環差圧ΔＰ）によって循環流量Ｑを制御してもよい。前記循環差圧ΔＰは、５ｋＰａ～３０ｋＰａの範囲内とすることが好ましい。 As another basic control, the control unit 240 performs the following processing on the ink circulation device 8 of the drawing device 300 .
That is, the control unit 240 controls the flow path R communicating with the nozzle 111 so that the average shear rate of the flow path R communicating with the nozzle 111 becomes a preset shear rate in the range of 1000 to 10000 [1/s]. (circulation flow rate Q), that is, the circulation differential pressure ΔP. For example, the ink circulation amount is in the range of 30 to 300 [ml/min].
For example, a liquid level sensor is provided to detect the liquid level of each of the sub-tanks 81 and 82, and the liquid levels of the tanks 81 and 82 are appropriately adjusted by operating the pumps 88 and 89 to achieve the target pressure P1 and pressure P2. of ink (circulation flow Q). In this case, a reserve ink tank serving as a buffer may be provided in the middle of the ink flow path 86 .
In addition, by appropriately changing the pressure applied to the pump 88 of the ink circulation device 8, the amount of ink filled in each of the sub-tanks 81 and 82, and the position of each of the sub-tanks 81 and 82 in the vertical direction (the direction of gravity) by means of actuators, The pressure P1 and the pressure P2 may be adjusted, and the circulation flow rate Q may be controlled by the pressure difference (circulation differential pressure ΔP) between the pressure P1 and the pressure P2. The circulation differential pressure ΔP is preferably within the range of 5 kPa to 30 kPa.
　また、制御部２４０は、ワークＷに対する描画を実行するための基本的な制御として、温度調整装置２２６によるインクの温度管理を行う。
　インクは、温度依存性があり、ゲル化剤を含む場合に、特に、温度の低下によってゲル化による粘性の増加が生じる。このため、制御部２４０は、温度調整装置２２６によって、インクジェットヘッド１００から吐出される前のインクを加温し、インクとワークＷの表面との間に温度差を設け、ワークＷの表面に付着したインクを効果的にゲル化させる制御を行っている。例えば、描画作業時において、チャンバー３３０内に設置されたワークＷの通常の温度が４０℃であることが分かっている場合には、温度調整装置２２６によって、インクジェットヘッド１００から吐出される前のインクを８０℃に加温する制御を行い、吐出前の粘性の低下を図り、吐出後、ワークＷの表面に付着したインクをゲル化させて付着性を向上させる。
　また、チャンバー３３０内にワークＷの温度検出手段を設け、検出温度に基づいて温度調整装置２２６によりインクの温度を調整する制御を行ってもよい。 Further, the control unit 240 performs temperature control of ink by the temperature adjustment device 226 as basic control for executing drawing on the work W. FIG.
The ink is temperature dependent, especially when it contains a gelling agent, a decrease in temperature causes an increase in viscosity due to gelation. For this reason, the control unit 240 heats the ink before it is ejected from the inkjet head 100 by the temperature adjustment device 226, creates a temperature difference between the ink and the surface of the work W, and attaches the ink to the surface of the work W. Control is performed to effectively gel the ink that has been applied. For example, during the drawing operation, if it is known that the normal temperature of the work W placed in the chamber 330 is 40° C., the temperature adjustment device 226 controls the ink before being ejected from the inkjet head 100. is controlled to be heated to 80° C. to reduce the viscosity before ejection, and after ejection, the ink adhering to the surface of the work W is gelled to improve adhesion.
Alternatively, a means for detecting the temperature of the workpiece W may be provided in the chamber 330, and control may be performed to adjust the temperature of the ink by the temperature adjusting device 226 based on the detected temperature.
　また、制御部２４０には、上記基本的な制御に付随して、より好適な描画を実現するための所定の制御を実行する姿勢制御部２４１、距離制御部２４２、ノズル選択制御部２４３、第一描画制御部２４４を備えている。これら姿勢制御部２４１、距離制御部２４２、ノズル選択制御部２４３及び第一描画制御部２４４は、制御部２４０のＣＰＵがソフトウェアを実行することにより実現する機能的構成である。但し、これらの機能を実行する回路などのハードウェアを制御部２４０に併設してもよい。
　なお、図１５には、「第二描画制御部２４５」、「第三描画制御部２４６」が記載されているが、これらは、後述する描画装置の他の例において、第一描画制御部２４４に替えて制御部２４０に搭載される構成であるため、第一描画制御部２４４を設ける場合には、「第二描画制御部２４５」、「第三描画制御部２４６」は設けられない。これらについては、別途、描画装置の他の例において説明する。 The control unit 240 also includes an attitude control unit 241, a distance control unit 242, a nozzle selection control unit 243, a nozzle selection control unit 243, a distance control unit 242, a nozzle selection control unit 243, and a control unit 241, which execute predetermined control for realizing more suitable drawing in addition to the basic control described above. A drawing control unit 244 is provided. The attitude control unit 241, the distance control unit 242, the nozzle selection control unit 243, and the first drawing control unit 244 are functional configurations realized by the CPU of the control unit 240 executing software. However, hardware such as a circuit for executing these functions may be provided together with the control unit 240 .
Note that although FIG. 15 describes a “second drawing control unit 245” and a “third drawing control unit 246”, these are the first drawing control unit 244 in another example of the drawing apparatus to be described later. Therefore, when the first drawing control unit 244 is provided, the "second drawing control unit 245" and the "third drawing control unit 246" are not provided. These will be described separately in another example of the drawing apparatus.
［姿勢制御部］
　上記姿勢制御部２４１は、ヘッドユニット２２４の姿勢制御を実行する。即ち、姿勢制御部２４１は、ワークＷの表面に対向する向き（例えば、垂直）でヘッドユニット２２４の各インクジェットヘッド１００がインクを吐出するようにロボットアーム３１０の動作制御を実行する。
　より詳細には、図１４に示すように、ヘッドユニット２２４の全ノズル１１１の中で左右方向における中心位置ｃ（図１６参照）に位置するノズル１１１から吐出されるインクが、ワークＷの表面に対して垂直となる向きを維持しながら、ノズル１１１の列方向（インクジェットヘッド１００における左右方向）がヘッドユニット２２４の走査方向に直交する方向に向けられた状態で走査されて描画が行われるように、ロボットアーム３１０が制御される。
　ヘッドユニット２２４の走査方向は、例えば、ワークＷの表面形状によって決定される。例えば、表面形状が平坦であれば、平坦面に沿って任意の方向に走査が行われ、表面形状が凸条のような形状の場合には、当該凸条に沿って走査が行われる。
　このとき、ヘッドユニット２２４の走査線上におけるワークＷの表面の傾きは、前述した三次元データ又は測距装置２２５の検出により取得することができる。 [Attitude control part]
The attitude control section 241 controls the attitude of the head unit 224 . That is, the posture control unit 241 controls the operation of the robot arm 310 so that each inkjet head 100 of the head unit 224 ejects ink in a direction facing the surface of the work W (for example, perpendicularly).
More specifically, as shown in FIG. 14, the ink ejected from the nozzle 111 located at the center position c (see FIG. 16) in the horizontal direction among all the nozzles 111 of the head unit 224 is applied to the surface of the work W. While maintaining the direction perpendicular to the head unit 224, the row direction of the nozzles 111 (the horizontal direction in the inkjet head 100) is oriented in the direction orthogonal to the scanning direction of the head unit 224 so that drawing is performed. , the robot arm 310 is controlled.
The scanning direction of the head unit 224 is determined by the surface shape of the workpiece W, for example. For example, if the surface shape is flat, scanning is performed in an arbitrary direction along the flat surface, and if the surface shape is like a ridge, scanning is performed along the ridge.
At this time, the inclination of the surface of the workpiece W on the scanning line of the head unit 224 can be obtained from the above-described three-dimensional data or detection by the distance measuring device 225 .
［距離制御部］
　距離制御部２４２は、姿勢制御部２４１によるヘッドユニット２２４の姿勢制御と共に実行されるヘッドユニット２２４の走査制御を実行する。即ち、距離制御部２４２は、前述した中心位置ｃのノズル１１１からワークＷの表面までの距離が前述した適正な吐出距離ｄを維持しつつヘッドユニット２２４の走査が行われるようにロボットアーム３１０の動作制御を実行する。
　より詳細には、図１４に示すように、前述した中心位置ｃ（図１６参照）に位置するノズル１１１の先端部から吐出方向の延長線上のワークＷの表面までの距離が吐出距離ｄを維持しながら、ヘッドユニット２２４が走査方向に搬送されるように、ロボットアーム３１０が制御される。
　このとき、ヘッドユニット２２４の走査線上におけるワークＷの表面までの距離は、前述した三次元データ又は測距装置２２５の検出により取得することができる。 [Distance control part]
The distance control section 242 executes scanning control of the head unit 224 which is executed together with attitude control of the head unit 224 by the attitude control section 241 . That is, the distance control unit 242 adjusts the robot arm 310 so that the scanning of the head unit 224 is performed while the distance from the nozzle 111 at the center position c to the surface of the workpiece W is maintained at the proper discharge distance d. Perform motion control.
More specifically, as shown in FIG. 14, the distance from the tip of the nozzle 111 located at the aforementioned center position c (see FIG. 16) to the surface of the workpiece W on the extension line in the ejection direction maintains the ejection distance d. Meanwhile, the robot arm 310 is controlled so that the head unit 224 is transported in the scanning direction.
At this time, the distance to the surface of the workpiece W on the scanning line of the head unit 224 can be obtained from the three-dimensional data described above or from the detection of the distance measuring device 225 .
［ノズル選択制御部］
　ノズル選択制御部２４３は、姿勢制御部２４１及び距離制御部２４２と共に実行されるインクジェットヘッド１００の吐出制御を実行する。即ち、ノズル選択制御部２４３は、ワークＷまでの距離が適正な吐出距離ｄ（目標値）から外れるノズル１１１について吐出を規制する動作制御を各インクジェットヘッド１００に対して実行する。 [Nozzle selection controller]
The nozzle selection control section 243 executes ejection control of the inkjet head 100 executed together with the attitude control section 241 and the distance control section 242 . That is, the nozzle selection control unit 243 performs operation control for each inkjet head 100 to restrict ejection of the nozzles 111 whose distance to the workpiece W is outside the proper ejection distance d (target value).
　図１６はノズル選択制御部２４３によるインクジェットヘッド１００の吐出制御の説明図である。
　前述したように、距離制御部２４２による走査制御によって、中心位置ｃのノズル１１１からワークＷの表面までの距離は、適正な吐出距離ｄを維持して描画が行われるが、ライン上に並んでインクを吐出する他のノズル１１１は、ワークＷの表面形状によっては、適正な吐出距離ｄを維持できない場合がある。
　例えば、ノズル１１１からワークＷの表面までの適正な吐出距離として許容される距離の範囲がｄに対して±Δｄとなる範囲である場合、ノズル選択制御部２４３は、ライン上に並んでインクを吐出する全てのノズル１１１についてワークＷの表面までの距離を取得し、その距離がｄに対して±Δｄの範囲外となるノズル１１１については、インクの吐出を禁止する制御を行う。
　なお、図１６において実線矢印は吐出許可状態を示し、点線は吐出禁止状態を示す。 16A and 16B are explanatory diagrams of ejection control of the inkjet head 100 by the nozzle selection control unit 243. FIG.
As described above, the distance from the nozzle 111 at the center position c to the surface of the workpiece W is maintained at the appropriate ejection distance d by scanning control by the distance control unit 242, and drawing is performed. Other nozzles 111 that eject ink may not be able to maintain a proper ejection distance d depending on the surface shape of the work W. FIG.
For example, if the range of the distance allowed as the proper ejection distance from the nozzle 111 to the surface of the workpiece W is within a range of ±Δd with respect to d, the nozzle selection control unit 243 arranges the ink in a line. The distance to the surface of the work W is obtained for all nozzles 111 that eject ink, and the nozzles 111 whose distance is outside the range of ±Δd with respect to d are controlled to prohibit ink ejection.
In FIG. 16, the solid line arrow indicates the discharge permitted state, and the dotted line indicates the discharge prohibited state.
　なお、ワークＷの表面形状が、例えば、左右方向に細かな凹凸を繰り返す形状等の場合には、上記制御では、吐出を行うノズル１１１と吐出を行わないノズル１１１とが交互に繰り返されて縞模様に描画を行う恐れがある。従って、ノズル選択制御部２４３として、以下のようにノズルの選択を行ってもよい。
　即ち、中心位置ｃのノズル１１１からワークＷの表面までの距離が適正な吐出距離ｄとなるように、ワークＷの表面に対してヘッドユニット２２４が位置する場合に、左側と右側のそれぞれについて、ワークＷの表面までの距離がｄに対して±Δｄの範囲外となるノズル１１１であって、中心位置ｃのノズル１１１から直近となるノズル１１１以遠のノズル１１１の全ての吐出を禁止する制御を行ってもよい。 If the surface shape of the work W is, for example, a shape that repeats fine unevenness in the left-right direction, the nozzles 111 that perform discharge and the nozzles 111 that do not perform discharge are alternately repeated in the above-described control. There is a risk of drawing in the pattern. Therefore, the nozzle selection control unit 243 may select nozzles as follows.
That is, when the head unit 224 is positioned with respect to the surface of the work W so that the distance from the nozzle 111 at the center position c to the surface of the work W is the proper discharge distance d, for each of the left and right sides, Control is performed to prohibit ejection from all nozzles 111 whose distance to the surface of the workpiece W is outside the range of ±Δd with respect to d, and which are farther than the nozzle 111 closest to the nozzle 111 at the center position c. you can go
　なお、走査方向に直交する方向に走査を繰り返してワークＷの表面を塗りつぶすように描画を行う場合には、ノズル選択制御部２４３を伴う走査が行われた場合に、毎回の走査において、吐出が行われたノズル１１１の範囲を記憶し、吐出が禁止されたノズル１１１による塗り残しが生じないように、次の走査を行うように制御すべきである。 When drawing is performed by repeatedly scanning in a direction orthogonal to the scanning direction so as to paint over the surface of the work W, when the scanning is performed with the nozzle selection control unit 243, ejection is performed in each scanning. The range of the nozzles 111 that have been performed should be stored, and control should be performed so that the next scan is not left uncoated by the nozzles 111 that are prohibited from discharging.
［第一描画制御部］
　第一描画制御部２４４は、ヘッドユニット２２４を所定の走査方向に走査して描画を行う際に、ピニング装置３２０がヘッドユニット２２４の進行方向を前とした場合に当該ヘッドユニット２２４の後側からインクを増粘させる配置を維持するようにロボットアーム３１０を制御する。
　例えば、図２のように、ヘッドユニット２２４をＭ方向（図の左方）に向かって走査する場合、ピニング装置３２０がヘッドユニット２２４の右側（進行方向後側）となる状態を維持して描画が行われる。
　これにより、走査方向の進路が変化する場合であっても、ワークＷの表面に付着したインクに追従するように近赤外線を照射することができ、効果的に吐出後のインクの粘性増加を図ることができる。 [First rendering control unit]
When performing drawing by scanning the head unit 224 in a predetermined scanning direction, the first drawing control unit 244 scans the head unit 224 from the rear side of the head unit 224 when the pinning device 320 sets the traveling direction of the head unit 224 to the front. Control the robot arm 310 to maintain the ink thickening configuration.
For example, as shown in FIG. 2, when the head unit 224 is scanned in the M direction (to the left in the drawing), the pinning device 320 is kept on the right side of the head unit 224 (rear side in the traveling direction). is done.
As a result, even when the course in the scanning direction changes, the near-infrared rays can be irradiated so as to follow the ink adhering to the surface of the work W, effectively increasing the viscosity of the ink after ejection. be able to.
［発明の実施形態の技術的効果］
　上記構成からなる描画装置３００は、インクジェットヘッド１００をロボットアーム３１０が保持して描画を行っている。インクジェットヘッド１００は、インクの液滴を個々のノズル１１１から吐出するので、塗料の噴霧の場合と異なり、被描画体であるワークＷの表面に対して、インクの液滴一つ一つを付着させて、ロスの少ない描画を行うことが可能となる。また、飛散が生じにくいので、目標とする位置及び範囲に適正にインクによる描画を行うことができ、マスキング等の事前準備負担を低減することが可能となる。また、飛散した余分なインクの後処理負担の低減も図ることが可能となる。
　さらに、描画装置３００は、インクジェットヘッド１００から吐出されたインクを増粘させるピニング装置３２０を備えているので、ワークＷの表面が上向きの水平面ではなく傾斜している場合や下向きの場合であっても、付着したインクの液だれを効果的に低減することができ、描画品質の向上を図ることが可能となる。 [Technical effect of the embodiment of the invention]
The drawing apparatus 300 configured as described above performs drawing while the robot arm 310 holds the inkjet head 100 . Since the inkjet head 100 ejects ink droplets from individual nozzles 111, unlike the case of spraying paint, the ink droplets are attached one by one to the surface of the work W, which is the object to be drawn. This makes it possible to perform drawing with little loss. In addition, since the ink is less likely to scatter, it is possible to appropriately draw with ink at the target position and range, and it is possible to reduce the burden of advance preparation such as masking. In addition, it is possible to reduce the burden of post-processing of excess ink that is scattered.
Furthermore, since the drawing device 300 includes the pinning device 320 that increases the viscosity of the ink ejected from the inkjet head 100, even if the surface of the work W is inclined or downward rather than horizontal, Also, it is possible to effectively reduce the dripping of the adhered ink, and it is possible to improve the drawing quality.
　また、描画装置３００のピニング装置３２０は、インクジェットヘッド１００から吐出後のインクをワークＷの表面上で増粘させるようにピニングを行うので、より良好にインクが付着し且つ前述したインクの液だれが抑制される。 In addition, the pinning device 320 of the drawing device 300 performs pinning so as to increase the viscosity of the ink ejected from the inkjet head 100 on the surface of the work W. is suppressed.
　また、ピニング装置３２０は、インクジェットヘッド１００と共にロボットアーム３１０に保持されているので、インクの付着位置とピニング装置３２０がインクにピニングを行う位置とが一定の関係を維持することができ、ロボットアーム３１０の動作に拘わらず、安定的に液だれの少ない描画を行うことが可能となる。 In addition, since the pinning device 320 is held by the robot arm 310 together with the inkjet head 100, it is possible to maintain a constant relationship between the ink adhesion position and the position at which the pinning device 320 pins the ink. Regardless of the operation of 310, it is possible to stably perform drawing with little dripping.
　また、制御部２４０は、姿勢制御部２４１を備えているので、ワークＷの表面に垂直となる向きでインクジェットヘッド１００から適正にインクが吐出されるため、より良好に描画を行うことができ、描画品質をさらに高く維持することが可能となる。また、ワークＷの表面が下向きの水平面に対して傾斜角度が0～180°の範囲であっても、これに対向してノズル１１１を適正な方向に向けることができ、あらゆる傾斜面に良好に描画を行うことが可能となる。 In addition, since the control unit 240 includes the attitude control unit 241, the ink is properly ejected from the inkjet head 100 in a direction perpendicular to the surface of the work W, so that better drawing can be performed. It is possible to maintain the drawing quality even higher. In addition, even if the surface of the work W is inclined at an angle of 0 to 180° with respect to the downward horizontal plane, the nozzle 111 can be directed in an appropriate direction to face the work W, and the nozzle 111 can be satisfactorily applied to any inclined plane. It is possible to draw.
　また、描画装置３００は、制御部２４０が距離制御部２４２を備えているので、ワークＷの表面に対して適正な吐出距離ｄを維持して描画を行うことができ、描画品質を高く維持することが可能となる。 In addition, since the control unit 240 of the drawing apparatus 300 includes the distance control unit 242, drawing can be performed while maintaining an appropriate discharge distance d with respect to the surface of the work W, and high drawing quality can be maintained. becomes possible.
　また、制御部２４０は、ノズル選択制御部２４３を備えているので、ワークＷの表面の凹凸や曲面形状によって適正な吐出距離ｄから外れてしまうノズル１１１の吐出が規制されるため、ワークＷの表面形状に拘わらず描画品質を高く維持することが可能となる。 In addition, since the control unit 240 includes the nozzle selection control unit 243, ejection from the nozzles 111 that deviate from the appropriate ejection distance d due to unevenness or curved shape of the surface of the work W is restricted. High drawing quality can be maintained regardless of the surface shape.
　また、制御部２４０は、第一描画制御部２４４を備えているので、インクジェットヘッド１００を所定の走査方向に走査して描画を行う場合に、走査方向の進路が変化する場合であっても、ピニング装置３２０がワークＷの表面に付着したインクに追従するようにピニングすることができ、効果的に吐出後のインクの粘性増加を図ることができる。 In addition, since the control unit 240 includes the first drawing control unit 244, when drawing is performed by scanning the inkjet head 100 in a predetermined scanning direction, even if the course in the scanning direction changes, The pinning device 320 can perform pinning so as to follow the ink adhering to the surface of the work W, and it is possible to effectively increase the viscosity of the ink after ejection.
　また、ピニング装置３２０は、吐出されたインクに赤外線、紫外線、エキシマ発光のいずれかのエネルギー線照射を行う照射装置であることから、吐出されたインクを効果的に乾燥又は硬化させることができ、より良好にインクが付着し且つより効果的に液だれを抑制することができる。特に、照射装置であれば、ピニングの範囲を絞りやすく、必要最小限の範囲でエネルギー線照射を行うことができ、描画範囲外の領域に対するエネルギー線照射の影響を最小限に抑えることが可能となる。 In addition, since the pinning device 320 is an irradiation device that irradiates the ejected ink with energy rays such as infrared rays, ultraviolet rays, or excimer emission, it is possible to effectively dry or cure the ejected ink. Ink adheres better and dripping can be suppressed more effectively. In particular, with an irradiation device, it is easy to narrow down the range of pinning, and it is possible to irradiate the energy ray within the minimum necessary range, and it is possible to minimize the influence of the energy ray irradiation on areas outside the drawing range. Become.
　また、ピニング装置３２０を、吐出されたインクを加熱する加熱装置から構成した場合にも、吐出されたインクを効果的に乾燥させることができ、より良好にインクが付着し且つより効果的に液だれを抑制することができる。また、ピニング装置として加熱装置を利用する場合には、熱量の調節が容易であるため、必要十分なピニングを実現することが可能となる。 In addition, when the pinning device 320 is composed of a heating device that heats the ejected ink, the ejected ink can be dried effectively, and the ink adheres more effectively and the liquid is more effectively dried. Who can be restrained? Moreover, when a heating device is used as the pinning device, it is possible to achieve necessary and sufficient pinning because the amount of heat can be easily adjusted.
　また、描画装置３００は、インクジェットヘッド１００により、せん断速度1000[1/s]での粘度が200[mPa・s]以下となるチキソ性を有するインクの吐出を行うので、吐出前にインクのせん断速度を高めておけば、粘度が低減して良好な吐出が可能となり、ワークＷの表面に付着後は、せん断速度の低下により速やかに粘度が上昇するので、ピニング装置３２０との作用と相まって、より効果的に液だれを抑制することが可能となる。 In addition, since the drawing apparatus 300 ejects thixotropic ink having a viscosity of 200 [mPa s] or less at a shear rate of 1000 [1/s] by the inkjet head 100, the ink is sheared before ejection. If the speed is increased, the viscosity is reduced, enabling good discharge. It becomes possible to suppress dripping more effectively.
　また、描画装置３００は、ノズル１１１に供給されるインクをせん断速度1000[1/s]以上で循環させるインク循環装置８を備えているので、チキソ性を有するインクの粘度を十分に低減してインクジェットヘッド１００のノズル１１１に供給することができ、良好な吐出を行うことが可能となる。
　特に、インク循環装置８は、インク循環量が30[ml/min]以上で循環させることにより、高いせん断速度でのインクの循環が可能となり、チキソ性を有するインクの吐出をより良好に行うことが可能となる。 In addition, since the drawing apparatus 300 includes the ink circulation device 8 that circulates the ink supplied to the nozzles 111 at a shear rate of 1000 [1/s] or higher, the viscosity of the thixotropic ink can be sufficiently reduced. It can be supplied to the nozzles 111 of the inkjet head 100, and good ejection can be performed.
In particular, the ink circulation device 8 circulates the ink at an ink circulation rate of 30 [ml/min] or more, thereby enabling the circulation of the ink at a high shear rate, and the thixotropic ink can be discharged more satisfactorily. becomes possible.
　また、インクジェットヘッド１００が吐出するインクに、紫外線硬化剤を加えた場合には、ピニング装置３２０が紫外線をインクに照射する構成とすることにより硬化させることができ、ワークＷの表面に付着したインクの液だれをより効果的に低減することが可能となる。
　さらに、上記インクに紫外線吸収剤を加えた場合には、紫外線硬化剤による硬化性が向上し、インクの液だれをより効果的に低減することが可能となる。
　さらに、上記インクに、ゲル化剤を加えた場合には、その温度依存性によりインクをゲル化させることができるので、インクの液だれをより効果的に低減することが可能となる。 Further, when an ultraviolet curing agent is added to the ink ejected by the inkjet head 100, the pinning device 320 can be configured to irradiate the ink with ultraviolet rays so that the ink adhered to the surface of the work W can be cured. It becomes possible to reduce the dripping of the liquid more effectively.
Furthermore, when an ultraviolet absorber is added to the ink, the curability of the ultraviolet curing agent is improved, and dripping of the ink can be reduced more effectively.
Furthermore, when a gelling agent is added to the ink, the ink can be gelled due to its temperature dependence, so that it is possible to more effectively reduce ink dripping.
　また、描画装置３００は、インクジェットヘッド１００から吐出される前のインクを加熱する温度調整装置２２６を備えているので、インクの温度依存性に応じて適正な温度でインクの吐出を行うことが可能となる。
　例えば、インクがゲル化剤を含む場合に、温度調整装置２２６によって溶解を生じる温度にインクを加温しておき、予め、ワークＷの表面温度との温度差を生じさせておくことにより、吐出後のインクをワークＷの表面で良好にゲル化を生じさせることができ、インクの液だれをより効果的に低減することが可能となる。 In addition, since the drawing apparatus 300 includes the temperature adjustment device 226 that heats the ink before it is ejected from the inkjet head 100, it is possible to eject the ink at an appropriate temperature according to the temperature dependency of the ink. becomes.
For example, when the ink contains a gelling agent, the temperature adjustment device 226 heats the ink to a temperature at which it melts, and by creating a temperature difference from the surface temperature of the work W in advance, the ink is discharged. The subsequent ink can be satisfactorily gelled on the surface of the work W, and ink dripping can be reduced more effectively.
［ヘッドユニット及びピニング装置による他の構成(1)］
　ヘッドユニット及びピニング装置による他の構成(1)について図１７に基づいて説明する。図１７はヘッドユニット及びピニング装置の他の構成(1)を適用した描画装置３００の正面図である。
　この構成では、ロボットアーム３１０の先端部に、１基のヘッドユニット２２４と２基のピニング装置３２０Ａ，３２０Ｂとが搭載されている。ピニング装置３２０Ａ，３２０Ｂは、いずれも、前述したピニング装置３２０と同一の構成である。また、ロボットアーム３１０の先端部において、一方のピニング装置３２０Ａはヘッドユニット２２４に対する後側に配置され、他方のピニング装置３２０Ｂはヘッドユニット２２４に対する前側に配置されている。
　なお、ここでいう「前側」と「後側」は、図３において説明したインクジェットヘッド１００における「前側」と「後側」を示す。図１７に記載の前後上下を示す矢印の方向も、ロボットアーム３１０における前後上下ではなく、インクジェットヘッド１００における前後上下の方向を記載している。 [Other configuration (1) with head unit and pinning device]
Another configuration (1) of the head unit and the pinning device will be described with reference to FIG. FIG. 17 is a front view of a drawing apparatus 300 to which another configuration (1) of the head unit and pinning device is applied.
In this configuration, one head unit 224 and two pinning devices 320A and 320B are mounted on the tip of the robot arm 310. As shown in FIG. Both of the pinning devices 320A and 320B have the same configuration as the pinning device 320 described above. At the tip of the robot arm 310, one pinning device 320A is arranged behind the head unit 224, and the other pinning device 320B is arranged in front of the head unit 224. As shown in FIG.
The terms "front side" and "rear side" here refer to the "front side" and "rear side" of the inkjet head 100 described with reference to FIG. The directions of the arrows indicating front, back, up and down directions shown in FIG.
　上記構成の描画装置３００の場合、制御部２４０は、前述した第一描画制御部２４４に替えて第二描画制御部２４５を備えている（図１５参照）。なお、第二描画制御部２４５も、制御部２４０のＣＰＵがソフトウェアを実行することにより実現する機能的構成である。但し、第二描画制御部２４５の機能を実行する回路などのハードウェアを制御部２４０に併設してもよい。 In the case of the rendering device 300 configured as described above, the control unit 240 includes a second rendering control unit 245 in place of the first rendering control unit 244 described above (see FIG. 15). The second drawing control unit 245 is also a functional configuration realized by the CPU of the control unit 240 executing software. However, hardware such as a circuit that executes the functions of the second drawing control unit 245 may be provided together with the control unit 240 .
　第二描画制御部２４５は、ヘッドユニット２２４をインクジェットヘッド１００における前側ＭＡに走査して描画を行う場合に、ピニング装置３２０Ａがヘッドユニット２２４に対して後側（ヘッドユニット２２４の進行方向を前とする場合にヘッドユニット２２４の後側）からワークＷの表面に吐出されたインクに近赤外線を照射してピニング動作を実行するようにロボットアーム３１０及びピニング装置３２０Ａを制御する。
　また、第二描画制御部２４５は、ヘッドユニット２２４をインクジェットヘッド１００における後側ＭＢに走査して描画を行う場合に、ピニング装置３２０Ｂがヘッドユニット２２４に対して前側（ヘッドユニット２２４の進行方向を前とする場合にヘッドユニット２２４の後側）からワークＷの表面に吐出されたインクに近赤外線を照射してピニング動作を実行するようにロボットアーム３１０及びピニング装置３２０Ｂを制御する。 When the head unit 224 scans the front side MA of the inkjet head 100 to perform drawing, the second drawing control unit 245 sets the pinning device 320A to the rear side of the head unit 224 (the moving direction of the head unit 224 is the front side). In this case, the robot arm 310 and the pinning device 320A are controlled so that the ink ejected onto the surface of the work W from the rear side of the head unit 224 is irradiated with near-infrared rays to perform the pinning operation.
In addition, the second drawing control unit 245 controls that when the head unit 224 scans the rear side MB of the inkjet head 100 to perform drawing, the pinning device 320B is positioned on the front side of the head unit 224 (the moving direction of the head unit 224 is The robot arm 310 and the pinning device 320B are controlled so that near-infrared rays are applied to the ink ejected onto the surface of the work W from the rear side of the head unit 224 (in the case of the front side) to perform the pinning operation.
　このように、描画装置３００がヘッドユニット及びピニング装置による他の構成(1)を搭載し、第二描画制御部２４５による走査制御が実施されることにより、前方への走査と後方への走査とが連続して行われる場合に、ヘッドユニット２２４とピニング装置３２０Ａ，３２０Ｂの配置を入れ替えることなく、液だれの発生を効果的に抑制しつつ円滑に連続的に描画を行うことが可能となる。 In this manner, the drawing apparatus 300 is equipped with another configuration (1) including the head unit and the pinning device, and scanning control is performed by the second drawing control unit 245, whereby forward scanning and backward scanning are performed. is continuously performed, it is possible to perform drawing smoothly and continuously while effectively suppressing the occurrence of dripping without changing the arrangement of the head unit 224 and the pinning devices 320A and 320B.
［ヘッドユニット及びピニング装置による他の構成(2)］
　ヘッドユニット及びピニング装置による他の構成(2)について図１８に基づいて説明する。図１８はヘッドユニット及びピニング装置の他の構成(2)を適用した描画装置３００の正面図である。
　この構成では、ロボットアーム３１０の先端部に、２基のヘッドユニット２２４Ａ，２２４Ｂと１基のピニング装置３２０とが搭載されている。ヘッドユニット２２４Ａ，２２４Ｂは、いずれも、前述したヘッドユニット２２４と同一の構成である。また、ロボットアーム３１０の先端部において、一方のヘッドユニット２２４Ａはピニング装置３２０に対する前側に配置され、他方のヘッドユニット２２４Ｂはピニング装置３２０に対する後側に配置されている。
　この場合も「前側」と「後側」は、図３において説明したインクジェットヘッド１００における「前側」と「後側」を示す。なお、二つのヘッドユニット２２４Ａ、２２４Ｂは、前後左右上下方向が一致した状態でロボットアーム３１０の先端部に取り付けられているものとする。図１８に記載の前後上下を示す矢印の方向も、ロボットアーム３１０における前後上下ではなく、インクジェットヘッド１００における前後上下の方向を記載している。 [Another configuration (2) with a head unit and a pinning device]
Another configuration (2) of the head unit and the pinning device will be described with reference to FIG. FIG. 18 is a front view of a drawing apparatus 300 to which another configuration (2) of the head unit and pinning device is applied.
In this configuration, two head units 224A and 224B and one pinning device 320 are mounted on the tip of a robot arm 310. As shown in FIG. Both of the head units 224A and 224B have the same configuration as the head unit 224 described above. At the tip of the robot arm 310 , one head unit 224 A is arranged on the front side with respect to the pinning device 320 and the other head unit 224 B is arranged on the rear side with respect to the pinning device 320 .
In this case as well, the terms "front side" and "rear side" refer to the "front side" and the "rear side" of the inkjet head 100 described with reference to FIG. It is assumed that the two head units 224A and 224B are attached to the tip of the robot arm 310 with the front, rear, left, right, and up and down directions aligned. The directions of the arrows indicating front, rear, top and bottom shown in FIG.
　上記構成の描画装置３００の場合、制御部２４０は、前述した第一描画制御部２４４に替えて第三描画制御部２４６を備えている（図１５参照）。なお、第三描画制御部２４６も、制御部２４０のＣＰＵがソフトウェアを実行することにより実現する機能的構成である。但し、第三描画制御部２４６の機能を実行する回路などのハードウェアを制御部２４０に併設してもよい。 In the case of the rendering device 300 configured as described above, the control unit 240 includes a third rendering control unit 246 in place of the first rendering control unit 244 described above (see FIG. 15). Note that the third drawing control unit 246 is also a functional configuration realized by the CPU of the control unit 240 executing software. However, hardware such as a circuit that executes the functions of the third drawing control unit 246 may be provided together with the control unit 240 .
　第三描画制御部２４６は、ヘッドユニット２２４をインクジェットヘッド１００における前側ＭＡに走査して描画を行う場合に、ピニング装置３２０に対して前側（ヘッドユニット２２４の進行方向を前とする場合にピニング装置３２０の前側）に位置するヘッドユニット２２４Ａからインクを吐出すると共にピニング装置３２０がワークＷの表面に吐出されたインクに近赤外線を照射してピニング動作を実行するように描画装置３００を制御する。
　また、第三描画制御部２４６は、ヘッドユニット２２４をインクジェットヘッド１００における後側ＭＢに走査して描画を行う場合に、ピニング装置３２０に対して後側（ヘッドユニット２２４の進行方向を前とする場合にピニング装置３２０の前側）に位置するヘッドユニット２２４Ｂからインクを吐出すると共にピニング装置３２０がワークＷの表面に吐出されたインクに近赤外線を照射してピニング動作を実行するように描画装置３００を制御する。 When the head unit 224 scans the front side MA of the inkjet head 100 to perform drawing, the third drawing control unit 246 controls the front side with respect to the pinning device 320 (the pinning device The drawing device 300 is controlled so that ink is ejected from the head unit 224A located on the front side of 320) and the pinning device 320 irradiates the ink ejected onto the surface of the work W with near-infrared rays to perform a pinning operation.
Further, when performing drawing by scanning the head unit 224 to the rear MB of the inkjet head 100, the third drawing control unit 246 controls the rear side of the pinning device 320 (the moving direction of the head unit 224 is the front side). Ink is ejected from the head unit 224B located on the front side of the pinning device 320, and the pinning device 320 irradiates the ink ejected onto the surface of the work W with near-infrared rays to perform a pinning operation. to control.
　このように、描画装置３００がヘッドユニット及びピニング装置による他の構成(2)を搭載し、第三描画制御部２４６による走査制御が実施されることにより、前方への走査と後方への走査とが連続して行われる場合に、ヘッドユニット２２４Ａ，２２４Ｂとピニング装置３２０の配置を入れ替えることなく、液だれの発生を効果的に抑制しつつ円滑に連続的に描画を行うことが可能となる。 In this manner, the drawing apparatus 300 is equipped with the other configuration (2) including the head unit and the pinning device, and the scanning control is performed by the third drawing control unit 246, whereby forward scanning and backward scanning are performed. is continuously performed, it is possible to perform drawing smoothly and continuously while effectively suppressing the occurrence of dripping without changing the arrangement of the head units 224A and 224B and the pinning device 320.
［調整機構］
　描画装置３００は、ワークＷの傾斜角度を調整する調整機構３４０を備える構成としてもよい。図１９は調整機構３４０の斜視図である。
　この調整機構３４０は、土台３４１と、ワークＷを支持する支持部３４２とを備え、土台３４１が支持部３４２を所定の回動軸Ｊ回りに回動可能に支持する。図１９の例では、土台３４１は、水平な回動軸Ｊ回りに支持部３４２を支持している。また、ワークＷが大型のものである場合には、土台３４１と支持部３４２とを二組有する構成として、ワークＷを両端部か支持する構成としてもよい。
　このような調整機構３４０を備えることで、ワークＷの構造によってロボットアーム３１０の先端部が入りにくい箇所やワークＷの底面等、通常の姿勢では描画が困難となる箇所に対して描画を良好に行うことが可能となる。
　また、ワークＷの表面の急勾配となる面を水平状態に近づけることも可能となるので、ピニング装置３２０の効果を相まって、インクの液だれをより効果的に抑制することが可能となる。 [Adjustment mechanism]
The drawing apparatus 300 may be configured to include an adjustment mechanism 340 that adjusts the tilt angle of the work W. FIG. 19 is a perspective view of the adjustment mechanism 340. FIG.
The adjustment mechanism 340 includes a base 341 and a support portion 342 that supports the workpiece W. The base 341 supports the support portion 342 so as to be rotatable about a predetermined rotation axis J. As shown in FIG. In the example of FIG. 19, the base 341 supports the support portion 342 around the horizontal rotation axis J. In the example of FIG. Further, when the work W is large, it may be configured to have two sets of the base 341 and the support portion 342 so that the work W is supported at both ends.
By providing such an adjustment mechanism 340, it is possible to draw well in places where drawing is difficult in a normal posture, such as a place where the tip of the robot arm 310 is difficult to enter due to the structure of the work W, or the bottom of the work W. can be done.
In addition, since it is possible to bring the steep surface of the work W closer to a horizontal state, it is possible to more effectively suppress ink dripping in combination with the effect of the pinning device 320 .
　なお、前述したように、ワークＷの表面の三次元データをロボットアーム３１０の座標系に展開してロボットアーム３１０の動作制御に用いる場合には、調整機構３４０によってワークＷの角度調整を行った場合には、調整角度を計測し、当該調整角度に基づいてロボットアーム３１０の座標系のワークＷの表面の座標値を演算しなおす必要がある。
　この場合、制御部２４０は、調整角度を入力されると、自動的にワークＷの表面の座標値を再演算する処理を行ってもよい。また、調整機構３４０の支持部３４２の軸に回転角度を検出するセンサを設け、その検出信号からロボットアーム３１０の座標系のワークＷの表面の座標値を再演算する機能を設けてもよい。 As described above, when the three-dimensional data of the surface of the work W is developed on the coordinate system of the robot arm 310 and used for controlling the motion of the robot arm 310, the angle of the work W is adjusted by the adjustment mechanism 340. In this case, it is necessary to measure the adjustment angle and recalculate the coordinate values of the surface of the workpiece W in the coordinate system of the robot arm 310 based on the adjustment angle.
In this case, the control unit 240 may automatically perform a process of recalculating the coordinate values of the surface of the work W when the adjustment angle is input. Further, a sensor for detecting the rotation angle may be provided on the shaft of the support portion 342 of the adjustment mechanism 340, and a function of recalculating the coordinate values of the surface of the workpiece W in the coordinate system of the robot arm 310 from the detection signal may be provided.
［その他］
　以上で説明した本発明の実施形態は、全ての点で例示であって制限的なものではないと考えられるべきである。すなわち、本発明の範囲は、上記した説明ではなくて特許請求の範囲によって示され、特許請求の範囲と均等の意味及び範囲内での全ての変更が含まれることが意図される。 [others]
The embodiments of the present invention described above should be considered illustrative in all respects and not restrictive. That is, the scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.
　上記実施形態では、描画装置３００がワークＷの表面を単色で塗りつぶす場合を例示したが、描画装置３００は、これに限らず、模様や線図、画像等をワークＷの表面に描画してもよい。
　また、ヘッドユニット２２４は、ロボットアーム３１０に対して着脱可能とし、各種の色彩を描画する他のヘッドユニット２２４と交換可能としてもよい。また、単体のヘッドユニット２２４に、各種色彩（例えば、Ｙ（イエロー）、Ｍ（マゼンタ）、Ｃ（シアン）、Ｋ（ブラック））ごとのインクジェットヘッド１００を設ける、あるいは、上記複数の色彩ごとのヘッドユニット２２４を一台のロボットアーム３１０で保持する構成とし、多色の画像形成による描画を行ってもよい。 In the above-described embodiment, the drawing device 300 paints the surface of the work W with a single color. good.
Also, the head unit 224 may be detachable from the robot arm 310 and may be replaceable with another head unit 224 that draws various colors. In addition, the single head unit 224 is provided with inkjet heads 100 for various colors (for example, Y (yellow), M (magenta), C (cyan), and K (black)), or The head unit 224 may be held by one robot arm 310, and drawing may be performed by multicolor image formation.
　また、ロボットアーム３１０として多関節型を例示したが、ロボットの形式は、これに限定されず、他の形式（例えば、直交座標型、スカラ型等）のロボットの構成を一部または全部に組み込んでもよい。 In addition, although a multi-joint type robot arm 310 has been exemplified, the type of robot is not limited to this, and other types of robot configuration (for example, Cartesian coordinate type, SCARA type, etc.) may be partially or wholly incorporated. It's okay.
　本発明は、インクの吐出により描画を行う描画装置及び描画方法について産業上の利用可能性がある。 The present invention has industrial applicability for a drawing apparatus and drawing method that perform drawing by ejecting ink.
８　インク循環装置
１００　インクジェットヘッド
１１１　ノズル
２２４，２２４Ａ，２２４Ｂ　ヘッドユニット
２２５　測距装置
２２６　温度調整装置（温度調整部）
２４０　制御部
２４１　姿勢制御部
２４２　距離制御部
２４３　ノズル選択制御部
２４４　第一描画制御部
２４５　第二描画制御部
２４６　第三描画制御部
３００　描画装置
３１０　ロボットアーム
３２０，３２０Ａ，３２０Ｂ　ピニング装置
３４０　調整機構
Ｐ　吐出位置
Ｗ　ワーク（被描画体）
ｄ　吐出距離 8 ink circulation device 100 inkjet head 111 nozzles 224, 224A, 224B head unit 225 distance measuring device 226 temperature adjustment device (temperature adjustment section)
240 control unit 241 attitude control unit 242 distance control unit 243 nozzle selection control unit 244 first drawing control unit 245 second drawing control unit 246 third drawing control unit 300 drawing device 310 robot arms 320, 320A, 320B pinning device 340 adjustment mechanism P discharge position W work (object to be drawn)
d Discharge distance

Claims (20)

  1. 　インクジェットヘッドと、
    　前記インクジェットヘッドを保持するロボットアームと、
    　前記インクジェットヘッドから吐出されたインクを増粘させるピニング装置と、
    　を備えることを特徴とする描画装置。     inkjet head,
    a robot arm that holds the inkjet head;
    a pinning device that thickens the ink ejected from the inkjet head;
    A rendering device comprising:
  2. 　前記ピニング装置は、前記インクジェットヘッドから吐出後のインクを被描画体の表面上で増粘させることを特徴とする請求項１に記載の描画装置。 The drawing apparatus according to claim 1, wherein the pinning device increases the viscosity of the ink ejected from the inkjet head on the surface of the object to be drawn.
  3. 　前記ピニング装置は、前記インクジェットヘッドと共に前記ロボットアームに保持されていることを特徴とする請求項１又は請求項２に記載の描画装置。 3. The drawing apparatus according to claim 1, wherein the pinning device is held by the robot arm together with the inkjet head.
  4. 　前記インクジェットヘッドのノズルから被描画体までの距離が目標値となるように前記ロボットアームを制御する距離制御部を備えることを特徴とする請求項１から請求項３のいずれか一項に記載の描画装置。 4. The method according to any one of claims 1 to 3, further comprising a distance control unit that controls the robot arm so that the distance from the nozzle of the inkjet head to the object to be printed becomes a target value. drawing device.
  5. 　前記インクジェットヘッドは、並んで設けられた複数のノズルを有し、
    　被描画体までの距離が目標値から外れるノズルの吐出を規制するノズル選択制御部を備えることを特徴とする請求項１から請求項４のいずれか一項に記載の描画装置。     The inkjet head has a plurality of nozzles arranged side by side,
    5. The drawing apparatus according to any one of claims 1 to 4, further comprising a nozzle selection control section that regulates ejection of nozzles whose distance to the object to be drawn deviates from a target value.
  6. 　被描画体の表面に対向する向きで前記インクジェットヘッドがインクを吐出するように前記ロボットアームを制御する姿勢制御部を備えることを特徴とする請求項１から請求項５のいずれか一項に記載の描画装置。 6. The robot arm according to any one of claims 1 to 5, further comprising a posture control unit that controls the robot arm so that the inkjet head ejects ink in a direction facing the surface of the object to be drawn. drawing device.
  7. 　被描画体の傾斜角度を調整する調整機構を備えることを特徴とする請求項１から請求項６のいずれか一項に記載の描画装置。 The drawing apparatus according to any one of claims 1 to 6, further comprising an adjustment mechanism for adjusting the tilt angle of the object to be drawn.
  8. 　前記ピニング装置は、吐出された前記インクにエネルギー線照射を行う照射装置であることを特徴とする請求項１から請求項７のいずれか一項に記載の描画装置。 The drawing apparatus according to any one of claims 1 to 7, wherein the pinning device is an irradiation device that irradiates the ejected ink with an energy beam.
  9. 　前記ピニング装置は、吐出された前記インクに赤外線、紫外線、エキシマ発光のいずれかのエネルギー線照射を行う照射装置であることを特徴とする請求項８に記載の描画装置。 9. The drawing apparatus according to claim 8, wherein the pinning device is an irradiation device that irradiates the ejected ink with energy rays of infrared rays, ultraviolet rays, or excimer emission.
  10. 　前記ピニング装置は、吐出された前記インクを加熱する加熱装置であることを特徴とする請求項１から請求項７のいずれか一項に記載の描画装置。 The drawing apparatus according to any one of claims 1 to 7, wherein the pinning device is a heating device that heats the ejected ink.
  11. 　前記インクジェットヘッドから吐出される前の前記インクの温度を調整する温度調整部を備えることを特徴とする請求項１から請求項１０のいずれか一項に記載の描画装置。 11. The drawing apparatus according to any one of claims 1 to 10, further comprising a temperature adjustment unit that adjusts the temperature of the ink before it is ejected from the inkjet head.
  12. 　前記インクは、紫外線硬化剤、紫外線吸収剤又はゲル化剤の少なくとも一つを含有することを特徴とする請求項１から請求項１１のいずれか一項に記載の描画装置。 The drawing apparatus according to any one of claims 1 to 11, wherein the ink contains at least one of an ultraviolet curing agent, an ultraviolet absorber, and a gelling agent.
  13. 　前記インクは、せん断速度1000[1/s]での粘度が200[mPa・s]以下となるチキソ性を有することを特徴とする請求項１から請求項１２のいずれか一項に記載の描画装置。 13. The drawing according to any one of claims 1 to 12, wherein the ink has thixotropy such that the viscosity at a shear rate of 1000 [1/s] is 200 [mPa s] or less. Device.
  14. 　前記インクジェットヘッドのノズルに供給される前記インクをせん断速度1000[1/s]以上で循環させる循環構造を備えることを特徴とする請求項１３に記載の描画装置。 14. The drawing apparatus according to claim 13, comprising a circulation structure that circulates the ink supplied to the nozzles of the inkjet head at a shear rate of 1000 [1/s] or higher.
  15. 　前記循環構造のインク循環量が30[ml/min]以上であることを特徴とする請求項１４に記載の描画装置。 15. The drawing apparatus according to claim 14, wherein the circulation structure has an ink circulation rate of 30 [ml/min] or more.
  16. 　前記ロボットアームは、前記インクジェットヘッドと前記ピニング装置とを共に保持し、
    　前記インクジェットヘッドを所定の走査方向に走査して描画を行う際に、前記ピニング装置が前記インクジェットヘッドの進行方向に対して当該インクジェットヘッドの後側からインクを増粘させる制御を行う第一描画制御部を備えることを特徴とする請求項１から請求項１５のいずれか一項に記載の描画装置。     The robot arm holds the inkjet head and the pinning device together,
    When drawing is performed by scanning the inkjet head in a predetermined scanning direction, the pinning device performs control to increase the viscosity of the ink from the rear side of the inkjet head with respect to the traveling direction of the inkjet head. First drawing control 16. The drawing apparatus according to any one of claims 1 to 15, further comprising a unit.
  17. 　前記ロボットアームは、二つの前記ピニング装置を前記インクジェットヘッドの両側に保持し、
    　前記インクジェットヘッドを所定の走査方向に平行な一方の方向に走査して描画を行う際に、前記インクジェットヘッドの前記一方の方向の進行方向に対して当該インクジェットヘッドの後側となる前記ピニング装置からインクを増粘させ、
    　前記インクジェットヘッドを前記走査方向に平行な前記一方の方向とは逆方向に走査して描画を行う際に、前記インクジェットヘッドの前記逆方向の進行方向に対して当該インクジェットヘッドの後側となる前記ピニング装置からインクを増粘させるように制御を行う第二描画制御部を備えることを特徴とする請求項１から請求項１５のいずれか一項に記載の描画装置。     the robot arm holds two pinning devices on opposite sides of the inkjet head;
    When drawing is performed by scanning the inkjet head in one direction parallel to a predetermined scanning direction, from the pinning device behind the inkjet head with respect to the traveling direction of the inkjet head in the one direction thicken the ink,
    When drawing is performed by scanning the inkjet head in a direction opposite to the one direction parallel to the scanning direction, the ink jet head located behind the inkjet head with respect to the traveling direction of the inkjet head in the opposite direction. 16. The drawing apparatus according to any one of claims 1 to 15, further comprising a second drawing control section that performs control to thicken the ink from the pinning device.
  18. 　前記ロボットアームは、二つの前記インクジェットヘッドを前記ピニング装置の両側に保持し、
    　前記インクジェットヘッドを所定の走査方向に平行な一方の方向に走査して描画を行う際に、前記インクジェットヘッドの前記一方の方向の進行方向に対して前記ピニング装置の前側となる前記インクジェットヘッドからインクを吐出させ、
    　前記インクジェットヘッドを前記走査方向に平行な前記一方の方向とは逆方向に走査して描画を行う際に、前記インクジェットヘッドの前記逆方向の進行方向に対して前記ピニング装置の前側となる前記インクジェットヘッドからインクを吐出させるように制御を行う第三描画制御部を備えることを特徴とする請求項１から請求項１５のいずれか一項に記載の描画装置。     The robot arm holds the two inkjet heads on both sides of the pinning device,
    When drawing is performed by scanning the inkjet head in one direction parallel to a predetermined scanning direction, the ink is ejected from the inkjet head located in front of the pinning device with respect to the traveling direction of the inkjet head in the one direction. and
    When drawing is performed by scanning the inkjet head in a direction opposite to the one direction parallel to the scanning direction, the inkjet head is on the front side of the pinning device with respect to the traveling direction of the inkjet head in the opposite direction. 16. The drawing apparatus according to any one of claims 1 to 15, further comprising a third drawing control section that controls ink to be ejected from the head.
  19. 　請求項１に記載の描画装置を用いて描画を行うことを特徴とする描画方法。 A drawing method, wherein drawing is performed using the drawing device according to claim 1.
  20. 　前記インクはゲル化剤を含み、
    　前記インクジェットヘッドから吐出される前のインクと被描画体との間に温度差を設け、前記被描画体に付着するインクのゲル化を促すことを特徴とする請求項１９に記載の描画方法。     the ink comprises a gelling agent;
    20. The drawing method according to claim 19, wherein a temperature difference is provided between the ink before being ejected from the inkjet head and the object to be drawn, thereby promoting gelling of the ink adhering to the object to be drawn.
PCT/JP2022/033214 2021-09-15 2022-09-05 Rendering device and rendering method WO2023042695A1 (en)

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JP2012040760A (en) * 2010-08-19 2012-03-01 Konica Minolta Holdings Inc Inkjet recording method
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