WO2014077335A1 - Ink discharging system - Google Patents

Ink discharging system Download PDF

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Publication number
WO2014077335A1
WO2014077335A1 PCT/JP2013/080833 JP2013080833W WO2014077335A1 WO 2014077335 A1 WO2014077335 A1 WO 2014077335A1 JP 2013080833 W JP2013080833 W JP 2013080833W WO 2014077335 A1 WO2014077335 A1 WO 2014077335A1
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WO
WIPO (PCT)
Prior art keywords
ink
electrode
nozzle
recording head
ejection system
Prior art date
Application number
PCT/JP2013/080833
Other languages
French (fr)
Japanese (ja)
Inventor
大西　勝
Original Assignee
株式会社ミマキエンジニアリング
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Publication date
Application filed by 株式会社ミマキエンジニアリング filed Critical 株式会社ミマキエンジニアリング
Publication of WO2014077335A1 publication Critical patent/WO2014077335A1/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
    • 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
    • B41J2/135—Nozzles
    • B41J2/14—Structure thereof only for on-demand ink jet heads
    • B41J2/14201—Structure of print heads with piezoelectric elements
    • B41J2/14233—Structure of print heads with piezoelectric elements of film type, deformed by bending and disposed on a diaphragm
    • 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
    • B41J2/015—Ink jet characterised by the jet generation process
    • B41J2/04—Ink jet characterised by the jet generation process generating single droplets or particles on demand
    • B41J2/06—Ink jet characterised by the jet generation process generating single droplets or particles on demand by electric or magnetic field
    • 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
    • B41J2202/00—Embodiments of or processes related to ink-jet or thermal heads
    • B41J2202/01—Embodiments of or processes related to ink-jet heads
    • B41J2202/04—Heads using conductive ink

Definitions

  • the present invention relates to an ink ejection system that ejects ink particles toward a recording medium such as paper.
  • a recording head having a plurality of nozzles for ejecting ink particles, an ink extruding device that pushes ink out of the nozzles by applying pressure to the ink stored in the recording head, and an ink
  • a device equipped with a flight assist device that assists the flight of the particles with electrostatic force see Patent Document 1.
  • This ink ejection system can eject ink particles by a combination of ink ejection by an ink extruding device and electrostatic attraction of ink by a flight assist device. Therefore, this ink ejection system can suppress the power consumption of the ink extruding device as compared with the configuration in which the ink particles are ejected only by the extrusion of the ink by the ink extruding device.
  • ink particles are ejected not only by the ink extrusion by the ink extrusion device but also by the electrostatic suction of the ink by the flight assist device. It is necessary to generate a high-voltage electrostatic field of about 1.5 kV, for example, depending on the apparatus. For this reason, the conventional ink ejection system has a problem that it is difficult to mount the nozzles on the recording head at a high density because it is necessary to ensure the dielectric strength between the nozzles in the recording head. In the ink ejection system, when the nozzle mounting density in the recording head is low, the number of ink particles that can be ejected per unit time is small, and thus the printing speed is slow.
  • an object of the present invention is to provide an ink ejection system capable of increasing the printing speed by increasing the density of nozzle mounting.
  • An ink ejection system includes a recording head having a plurality of nozzles for ejecting ink particles toward a recording medium, and applying pressure to the ink stored in the recording head, An ink extruding device that extrudes the particles from the nozzle, a flying assist device that assists the flying of the particles by electrostatic force, and a controller that controls operations of the ink extruding device and the flying assist device,
  • the control unit charges the flying auxiliary device with the ink stored in the recording head, causes the ink extrusion device to discharge the particles of the ink charged by the flying auxiliary device from the nozzle, and
  • the flying assist device is assisted by the electrostatic force to fly the particles ejected from the nozzle by an ink extrusion device.
  • the pressure applied to the ink by the ink extruding device is a pressure at which the ink can be ejected from the nozzle only by the ink extruding device of the ink extruding device and the flight assisting device, and the flying The pressure is such that the particles having a size less than the minimum size that can reach the recording medium against air resistance when the auxiliary device does not assist the flight are discharged from the nozzle.
  • the ink ejection system according to the present invention can eject the ink particles from the nozzle only by the ink extrusion device of the ink extrusion device and the flight assist device. Therefore, it is not necessary to generate a high-voltage electrostatic field. Therefore, the ink ejection system of the present invention can mount the nozzles on the recording head at a higher density than before even if the necessary dielectric strength between the nozzles in the recording head is ensured. can do.
  • the flying assist device may include a charging electrode that charges the ink stored in the recording head and an electrostatic force that applies the electrostatic force to the particles ejected from the nozzle.
  • a pair of electrostatic field electrodes for generating an electric field the pair of electrostatic field electrodes being discharged from the nozzle with the same polarity electrode charged to the same kind of polarity as the particles discharged from the nozzle
  • the different polarity electrodes that are charged to different polarities the same polarity electrodes are disposed on the recording head side with respect to the recording medium, and the different polarity electrodes are: It may be disposed on the recording medium side with respect to the same polarity electrode.
  • the ink ejection system of the present invention can easily extend the flying distance of the ink particles by extending the distance between the same polarity electrode and the different polarity electrode.
  • the same polarity electrode may constitute at least a part of a member of the recording head where the nozzle is formed.
  • the ink ejection system of the present invention can be realized with a simple configuration as compared with the configuration in which the recording head and the same polarity electrode are separately provided.
  • the charging electrode may include at least a part of the same polarity electrode.
  • the ink ejection system of the present invention can be realized with a simple configuration as compared with the configuration in which the charging electrode and the same polarity electrode are separately provided.
  • the charging electrode may be the same polarity electrode.
  • the ink ejection system of the present invention can be realized with a simple configuration as compared with a configuration in which at least a part of the charging electrode is different from the same polarity electrode.
  • the voltage applied between the pair of electrostatic field electrodes is a pulse voltage having a width wider than a pulse voltage for causing the ink extruding device to extrude the particles of the ink from the nozzle. It may be.
  • the ink ejection system of the present invention can improve safety compared to a configuration in which a high voltage is always applied between a pair of electrostatic field electrodes.
  • the recording head is formed with a pressure chamber in which the pressure is applied to the stored ink by the ink pushing device, and the ink pushing device is the ink pushing device.
  • a pressure chamber drive electrode provided inside the pressure chamber, and the charging electrode may include at least a part of the pressure chamber drive electrode. good.
  • the ink ejection system of the present invention can be realized with a simple configuration as compared with the configuration in which the charging electrode and the pressure chamber driving electrode are separately provided.
  • the ink ejection system of the present invention can increase the printing speed by increasing the density of nozzle mounting.
  • FIG. 1 is a perspective view of an ink jet printer according to a first embodiment of the present invention.
  • FIG. 2 is a bottom view of a recording head mounted on a carriage of the ink jet printer shown in FIG. 1. It is the schematic diagram seen from the front of the ink discharge system with which the inkjet printer shown in FIG. 1 is equipped. It is a figure which shows each voltage application part and control part of the ink discharge system shown in FIG.
  • FIG. 5 is a flowchart of the operation of the control unit shown in FIG. 4 when one ink droplet from a nozzle reaches a recording medium. It is the schematic diagram seen from the front of the ink discharge system with which the inkjet printer which concerns on the 2nd Embodiment of this invention is equipped.
  • FIG. 1 is a perspective view of an ink jet printer according to a first embodiment of the present invention.
  • FIG. 2 is a bottom view of a recording head mounted on a carriage of the ink jet printer shown in FIG. 1.
  • It is the schematic diagram
  • FIG. 7 is a flowchart of the operation of the control unit of the ink ejection system shown in FIG. 6 when one ink droplet from a nozzle reaches the recording medium.
  • It is the schematic diagram seen from the front of the ink discharge system with which the inkjet printer which concerns on the 2nd Embodiment of this invention is equipped, Comprising: It is a figure of the example different from the example shown in FIG. It is the schematic diagram seen from the front of the ink discharge system with which the inkjet printer which concerns on the 2nd Embodiment of this invention is equipped, Comprising: It is a figure of an example different from the example shown in FIG.
  • FIG. 11 is a flowchart of the operation of the control unit of the ink ejection system shown in FIG. 10 in a case where one droplet of ink reaches a recording medium from a nozzle.
  • FIG. 11 is a flowchart of the operation of the control unit of the ink ejection system shown in FIG. 10 in a case where one droplet of ink reaches a recording medium from a nozzle.
  • FIG. 11 is a flowchart of the operation of the control unit of the ink ejection system shown in FIG. 10 in a case where one droplet of ink reaches a recording medium from a nozzle.
  • FIG. 11 is a flowchart of the operation of the control unit of the ink ejection system shown in FIG. 10 in a case where one droplet of ink reaches a recording medium from a nozzle.
  • FIG. 11 is a flowchart of the operation of the control unit of the ink ejection system shown in FIG. 10 in a case where one droplet of
  • FIG. 1 is a perspective view of an ink jet printer 10 according to the present embodiment.
  • the inkjet printer 10 includes a main body 11 extending in the main scanning direction indicated by an arrow 10a, and a transport device 12 that transports a recording medium 90 such as paper.
  • the main body 11 includes a guide rail 11a extending in the main scanning direction indicated by an arrow 10a, and a carriage 11b supported by the guide rail 11a so as to be movable in the main scanning direction indicated by the arrow 10a.
  • the conveying device 12 is a device that conveys the recording medium 90 in a sub-scanning direction indicated by an arrow 10b with respect to a recording head 30 described later of the main body 11.
  • FIG. 2 is a bottom view of the recording head 30 mounted on the carriage 11b.
  • the recording head 30 includes a plurality of nozzles 31a for ejecting ink particles (hereinafter referred to as “ink droplets”) toward a recording medium 90 (see FIG. 1).
  • a plate 31 is provided.
  • the recording head 30 is an on-demand ink jet head.
  • FIG. 3 is a schematic view seen from the front of the ink ejection system 20 provided in the inkjet printer 10.
  • one nozzle 31 a among the plurality of nozzles 31 a of the recording head 30 is drawn in order to facilitate understanding of the ink ejection system 20.
  • the ink ejection system 20 includes all the nozzles 31 a of the recording head 30.
  • the ink ejection system 20 includes the above-described recording head 30, an ink extrusion device 40 that pushes the ink droplet 20 b from the nozzle 31 a by applying pressure to the ink 20 a stored in the recording head 30, and And a flight assist device 50 that assists the flight of the ink droplet 20b with an electrostatic force.
  • the recording head 30 includes the above-described nozzle plate 31, a wall portion 32 attached to the nozzle plate 31, a shear mode piezo element 33 attached to the wall portion 32, and an electrode attached to the wall portion 32. 34, and an electrode 35 and an electrode 36 attached to the piezo element 33.
  • the nozzle plate 31, the wall portion 32, and the piezo element 33 form a pressure chamber 30a in which pressure is applied to the stored ink 20a by the ink extruding device 40.
  • the pressure chamber 30a is connected to a supply path (not shown) for the ink 20a, and new ink 20a is supplied from the supply path each time an ink droplet 20b is ejected from the nozzle 31a. .
  • the pressure chamber 30 a appears on the front side of the recording head 30 in FIG. 3 in order to facilitate understanding of the ink ejection system 20. However, actually, the pressure chamber 30 a is covered by the wall portion 32 on the front side of the recording head 30 and does not appear on the front side of the recording head 30. Similarly, the space inside the nozzle 31 a appears on the front side of the recording head 30 in FIG. 3 in order to facilitate understanding of the ink ejection system 20. However, actually, the space inside the nozzle 31 a is covered with the nozzle plate 31 on the front side of the recording head 30, and does not appear on the front side of the recording head 30.
  • the nozzle plate 31 includes a plate body 31b attached to the wall portion 32, and an electrode 31c provided on the surface of the plate body 31b opposite to the wall portion 32 side.
  • the electrode 34 is provided inside the pressure chamber 30a.
  • the plate body 31b and the wall 32 are made of an insulator such as insulating plastic.
  • the ink extruding device 40 includes the piezoelectric element 33, the electrode 35, and the electrode 36 described above, and a driving voltage applying unit 41 that applies a voltage between the electrode 35 and the electrode 36.
  • the electrode 35 and the electrode 36 are electrodes for driving the ink extruding device 40.
  • the flying assist device 50 includes the above-described electrode 31c and electrode 34, an electrode 51 disposed on the recording medium 90 side with respect to the electrode 31c, and a charging voltage application unit that applies a voltage between the electrode 31c and the electrode 34. 52 and an electrostatic field voltage application unit 53 for applying a voltage between the electrode 31c and the electrode 51.
  • the electrode 31c is disposed on the recording head 30 side with respect to the recording medium 90.
  • the electrode 34 is an electrode for charging the ink 20a accommodated in the recording head 30, and constitutes the charging electrode of the present invention.
  • the electrode 31c is an electrode that is charged to the same kind of polarity as the ink droplet 20b ejected from the nozzle 31a, and constitutes the same polarity electrode of the present invention.
  • the electrode 51 is an electrode that is charged to a polarity different from that of the ink droplet 20b ejected from the nozzle 31a, and constitutes a different polarity electrode of the present invention. That is, the electrode 31c and the electrode 51 generate an electrostatic field that gives an electrostatic force to the ink droplet 20b ejected from the nozzle 31a, and constitute a pair of electrostatic field electrodes of the present invention.
  • FIG. 4 is a diagram showing each voltage application unit and the control unit 60 of the ink ejection system 20.
  • the ink ejection system 20 includes a control unit 60 shown in FIG.
  • the control unit 60 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores programs and various data in advance, and a RAM (Random Access Memory) used as a work area of the CPU. ing.
  • the CPU executes a program stored in the ROM.
  • the control unit 60 can control the operation of the ink extruding device 40 (see FIG. 3) by controlling the driving voltage applying unit 41.
  • the control unit 60 can control the operation of the flight assist device 50 (see FIG. 3) by controlling the charging voltage application unit 52 and the electrostatic field voltage application unit 53.
  • FIG. 5 is a flowchart of the operation of the control unit 60 when one ink droplet 20b reaches the recording medium 90 from the nozzle 31a.
  • the control unit 60 applies the voltage Va between the electrode 31c and the electrode 34 by the charging voltage application unit 52 for a time Ta (S71). Therefore, the flying assist device 50 charges the ink 20a inside the pressure chamber 30a positively, for example, by injection of electric charge from the electrode 34 or polarization due to the electric field generated by the electrode 34.
  • the time Ta is a time longer than the dielectric relaxation time ⁇ of the ink 20a.
  • the dielectric relaxation time ⁇ is expressed by Equation 1 based on the dielectric constant ⁇ 0 of vacuum, the relative dielectric constant ⁇ r of the ink 20a, and the specific resistance ⁇ of the ink 20a.
  • the ink 20a may be an ink having a specific resistance ⁇ of about 10 7 ⁇ cm or less, preferably 10 6 ⁇ cm or less.
  • the control unit 60 starts applying the voltage Vb between the electrode 31c and the electrode 51 by the electrostatic field voltage applying unit 53 after the processing of S71 (S72). Therefore, the flying assist device 50 generates an electrostatic field between the electrode 31 c and the electrode 51.
  • the control unit 60 applies the voltage Vc between the electrode 35 and the electrode 36 by the driving voltage applying unit 41 after the process of S72 (S73). Therefore, the ink extruding device 40 applies pressure to the ink 20a inside the pressure chamber 30a by the piezo element 33 when the piezo element 33 is deformed by the application of the voltage Vc.
  • pressure is applied to the ink 20a inside the pressure chamber 30a by the piezo element 33, one ink droplet 20b of the ink 20a inside the pressure chamber 30a charged in S71 is ejected from the nozzle 31a.
  • the pressure that the ink extruding device 40 applies to the ink 20a is a pressure at which the ink droplet 20b can be ejected from the nozzle 31a only by the ink extruding device 40 of the ink extruding device 40 and the flight assisting device 50. That is, the voltage Vc is a voltage at which the ink droplet 20b can be ejected from the nozzle 31a only by the ink extruding device 40 of the ink extruding device 40 and the flight assisting device 50.
  • the combination of the voltage Va for applying the charge for assisting the flying of the ink droplet 20b to the ink 20a and the voltage Vb for generating the electrostatic field for assisting the flying of the ink droplet 20b is the combination of the ink extruding device 40 and the flying.
  • the voltage is such that the ink droplet 20b cannot be ejected from the nozzle 31a only by the flight assisting device 50 among the assisting devices 50.
  • the pressure applied by the ink extruding device 40 to the ink 20a is less than the minimum size that can reach the recording medium 90 against the air resistance R described later when the flight assist device 50 does not assist the flight.
  • This is the pressure at which the droplet 20b is discharged from the nozzle 31a. That is, the voltage Vc is a voltage that generates a small ink droplet 20b that cannot reach the recording medium 90 against the air resistance R when there is no flight assistance by the flight assist device 50.
  • the ink droplet 20b ejected from the nozzle 31a by the ink extruding device 40 is assisted by the electrostatic force generated by the flight assist device 50 in S72.
  • the ink droplet 20b ejected from the nozzle 31a and flying between the electrode 31c and the electrode 51 receives an electrostatic attractive force Fq.
  • the ink droplet 20b ejected from the nozzle 31a receives the air resistance R. Therefore, by adjusting the voltages Va, Vb, and Vc so that the electrostatic attractive force Fq and the air resistance R received by the ink droplet 20b are equal, the speed of the ink droplet 20b ejected from the nozzle 31a decreases.
  • the recording medium 90 can be reached.
  • the electrostatic attractive force Fq is expressed by Equation 2 based on the charge q charged in the ink droplet 20b and the voltage Vb between the electrode 31c and the electrode 51.
  • the air resistance R is expressed by the following equation 3 based on the density ⁇ of the air around the ink droplet 20b, the resistance proportional coefficient C, the forward projection area S of the ink droplet 20b, and the velocity v of the ink droplet 20b. It is expressed in The initial velocity of the ink droplet 20b ejected from the nozzle 31a by the ink extruding device 40 is determined by the magnitude of the voltage Vc applied between the electrode 35 and the electrode 36.
  • the control unit 60 determines whether or not the predetermined time has elapsed since the execution of the process of S73 until it is determined that the predetermined time has elapsed since the execution of the process of S73. (S74).
  • This predetermined time is a time until the ink droplet 20b ejected from the nozzle 31a reaches the recording medium 90, and the flying speed of the ink droplet 20b and the distance between the nozzle 31a and the recording medium 90 are as follows. Can be obtained on the basis.
  • control unit 60 determines in S74 that the predetermined time has elapsed since the execution of the process of S73, the application of the voltage Vb by the electrostatic field voltage application unit 53 is terminated (S75), and the operation shown in FIG. Exit.
  • the control unit 60 starts applying the voltage Vb between the electrode 31c and the electrode 51 by the electrostatic field voltage application unit 53 (S72), and then the drive voltage application unit 41.
  • the voltage Vc is applied between the electrode 35 and the electrode 36 (S73), but an electrostatic field may be generated during the flight of the ink droplet 20b.
  • the application of the voltage Vb between the electrodes 31c and 51 by the electrostatic field voltage applying unit 53 may be started.
  • control unit 60 can cause one ink droplet 20b to reach the recording medium 90 from the nozzle 31a by the operation shown in FIG. 5, but similarly, a plurality of ink droplets 20b are continuously provided from the nozzle 31a.
  • the recording medium 90 can be reached.
  • the controller 60 causes the plurality of ink droplets 20b to continuously reach the recording medium 90 from the nozzle 31a
  • the voltage Vc applied between the electrode 35 and the electrode 36 by the applying unit 41 can be a pulse voltage having the same cycle.
  • the control unit 60 sets the pulse width of the voltage Va, which is a pulse voltage, as the time Ta.
  • control unit 60 delays the cycle of the voltage Vc, which is a pulse voltage, by a time Ta from the cycle of the voltage Va, which is a pulse voltage. Further, the control unit 60 applies the voltage Vb between the electrode 31 c and the electrode 51 by the electrostatic field voltage application unit 53 at least while the ink droplet 20 b is flying between the electrode 31 c and the electrode 51.
  • the ink ejection system 20 can eject the ink droplet 20b from the nozzle 31a only by the ink extrusion device 40 of the ink extrusion device 40 and the flight assisting device 50. Therefore, it is not necessary to generate a high-voltage electrostatic field by the flight assist device 50. Therefore, the ink ejection system 20 can mount the nozzles 31a on the recording head 30 at a higher density than the conventional one even if the necessary dielectric strength between the nozzles 31a in the recording head 30 is ensured. Can be faster. For this reason, the ink ejection system 20 is suitable for printing an image having a large area, for example.
  • the ink ejection system 20 cannot reach the recording medium 90 against the air resistance R when there is no flight assistance by the flight assist device 50, for example, ink of a minute size of 1 pl (picoliter) or less. Since the droplet 20b reaches the recording medium 90, a very thin line can be printed on the recording medium 90.
  • the ink ejection system 20 causes the recording medium 90 to have a very thin line of 10 ⁇ m or less, such as 5 ⁇ m, by reaching the recording medium 90 with fine ink droplets 20b of the ink 20a in which metal nanoparticles such as nano silver are dispersed.
  • Printed wiring can be printed on top.
  • the ink ejection system 20 can easily extend the flight distance of the ink droplet 20b by extending the distance between the electrode 31c and the electrode 51.
  • the ink ejection system 20 can cause the ink droplet 20b of 0.01 pl to reach the recording medium 90 even if the distance between the nozzle 31a and the recording medium 90 is 5 mm.
  • the electrode 31c that is the same polarity electrode constitutes a part of the nozzle plate 31 that is a member in which the nozzle 31a is formed in the recording head 30, the recording head 30; Compared to a configuration in which the same polarity electrodes are provided separately, the configuration can be realized with a simple configuration.
  • FIG. 6 is a schematic view seen from the front of the ink ejection system 120 provided in the ink jet printer according to the second embodiment of the present invention.
  • the configuration of the inkjet printer according to the present embodiment is the same as the configuration in which the inkjet printer 10 (see FIG. 1) includes the ink ejection system 120 shown in FIG. 6 instead of the ink ejection system 20 (see FIG. 3). is there.
  • the configuration of the ink ejection system 120 is the same as the configuration provided in the ink ejection system 20 instead of the recording head 30 (see FIG. 3) and the flying assistance device 50 (see FIG. 3). It is.
  • the configuration of the recording head 130 includes a nozzle plate 131 that is an electrode as a whole and an electrode 132 that is electrically connected to the nozzle plate 131, a nozzle plate 31 (see FIG. 3), and an electrode 34 (see FIG. 3).
  • the recording head 30 has the same configuration as that shown in FIG.
  • the flying assist device 150 applies voltage between the nozzle plate 131 and the electrode 132 described above, the electrode 51 disposed on the recording medium 90 side with respect to the nozzle plate 131, and the nozzle plate 131 and the electrode 51. Part 151.
  • the nozzle plate 131 is an electrode that is charged to the same kind of polarity as the ink droplet 20b ejected from the nozzle 31a, and constitutes the same polarity electrode of the present invention. That is, the nozzle plate 131 constitutes a pair of electrostatic field electrodes of the present invention together with the electrode 51.
  • the nozzle plate 131 is an electrode for charging the ink 20a stored in the recording head 130, and constitutes the charging electrode of the present invention.
  • the electrode 132 is an electrode for charging the ink 20a accommodated in the recording head 130, and constitutes the charging electrode of the present invention.
  • FIG. 7 is a flowchart of the operation of the control unit 60 when one ink droplet 20b reaches the recording medium 90 from the nozzle 31a.
  • the control unit 60 starts applying the voltage Vb to the nozzle plate 131 by the voltage application unit 151 (S171). Therefore, the flying assist device 150 charges the ink 20a inside the pressure chamber 30a, for example, positively by injection of charges from the nozzle plate 131 and the electrode 132 or polarization due to an electric field generated by the nozzle plate 131 and the electrode 132. Let Further, the flying assist device 150 generates an electrostatic field between the nozzle plate 131 and the electrode 51.
  • the control unit 60 determines whether or not the time Ta has elapsed since the execution of the process of S171 until it is determined that the time Ta has elapsed since the execution of the process of S171 (S172). ).
  • This time Ta is the same as the time Ta according to the first embodiment.
  • the ink 20a may be an ink having a specific resistance ⁇ of about 10 9 ⁇ cm or less, preferably 10 8 ⁇ cm or less.
  • the driving voltage application unit 41 applies the voltage Vc between the electrode 35 and the electrode 36 (S173). Therefore, the ink extruding device 40 applies pressure to the ink 20a inside the pressure chamber 30a by the piezo element 33 when the piezo element 33 is deformed by the application of the voltage Vc.
  • pressure is applied to the ink 20a inside the pressure chamber 30a by the piezo element 33, one ink droplet 20b out of the ink 20a inside the pressure chamber 30a charged in S171 is ejected from the nozzle 31a.
  • the pressure that the ink extruding device 40 applies to the ink 20a is a pressure at which the ink droplet 20b can be ejected from the nozzle 31a only by the ink extruding device 40 of the ink extruding device 40 and the flight assisting device 150. That is, the voltage Vc is a voltage at which the ink droplet 20b can be ejected from the nozzle 31a only by the ink extrusion device 40 of the ink extrusion device 40 and the flight assist device 150.
  • the voltage Vb for assisting the flying of the ink 20a is a voltage at which the ink droplet 20b cannot be ejected from the nozzle 31a only by the flying assist device 150 of the ink extruding device 40 and the flying assist device 150.
  • the pressure applied to the ink 20a by the ink extruding device 40 is less than the minimum size of the ink droplet 20b that can reach the recording medium 90 against the air resistance R when there is no flying assistance by the flying assistance device 150.
  • the pressure at which the gas is discharged from the nozzle 31a is the pressure at which the gas is discharged from the nozzle 31a. That is, the voltage Vc is a voltage that generates a small ink droplet 20b that cannot reach the recording medium 90 against the air resistance R when there is no flight assistance by the flight assist device 150.
  • the ink droplet 20b ejected from the nozzle 31a by the ink extruding device 40 is assisted by the electrostatic force generated by the flight assist device 150 in S171.
  • the control unit 60 determines whether or not the predetermined time has elapsed since the execution of the process of S173 until it is determined that the predetermined time has elapsed since the execution of the process of S173. (S174).
  • This predetermined time is a time until the ink droplet 20b ejected from the nozzle 31a reaches the recording medium 90, and the flying speed of the ink droplet 20b and the distance between the nozzle 31a and the recording medium 90 are as follows. Can be obtained on the basis.
  • control unit 60 ends the application of the voltage Vb by the voltage application unit 151 (S175) and ends the operation shown in FIG. .
  • control unit 60 can cause one ink droplet 20b to reach the recording medium 90 from the nozzle 31a by the operation shown in FIG. 7, but similarly, a plurality of ink droplets 20b are continuously delivered from the nozzle 31a.
  • the recording medium 90 can be reached.
  • the controller 60 causes the plurality of ink droplets 20b to reach the recording medium 90 continuously from the nozzle 31a
  • the voltage Vc applied between the electrode 35 and the electrode 36 by the driving voltage applying unit 41 is set as a pulse voltage. be able to.
  • the control unit 60 sets the cycle of the voltage Vc, which is a pulse voltage, to a time Ta or more.
  • the control unit 60 applies the voltage Vb between the nozzle plate 131 and the electrode 51 by the voltage application unit 151 at least while the ink droplet 20 b is flying between the nozzle plate 131 and the electrode 51.
  • the ink ejection system 120 can eject the ink droplet 20b from the nozzle 31a only by the ink extrusion device 40 of the ink extrusion device 40 and the flight assist device 150. Therefore, it is not necessary to generate a high-voltage electrostatic field by the flying assist device 150. Therefore, the ink ejection system 120 can mount the nozzles 31a on the recording head 130 at a higher density than the conventional one even if the necessary withstand voltage between the nozzles 31a in the recording head 130 is ensured. Can be faster.
  • the ink ejection system 120 causes the ink droplet 20b of a minute size that cannot reach the recording medium 90 against the air resistance R to reach the recording medium 90 when there is no flying assistance by the flying assist device 150. Therefore, extremely thin lines can be printed on the recording medium 90.
  • the ink ejection system 120 can easily extend the flight distance of the ink droplet 20b by extending the distance between the nozzle plate 131 and the electrode 51.
  • the nozzle plate 131 that is the same polarity electrode constitutes a member in which the nozzle 31a is formed in the recording head 130, so that the recording head 130 and the same polarity electrode are separately provided. Compared to the provided configuration, it can be realized with a simple configuration.
  • the charging electrode includes a part of the same polarity electrode, that is, the nozzle plate 131, as shown in FIG. 3, the charging electrode, that is, the electrode 34, and the same polarity electrode, that is, the electrode 31c.
  • the charging electrode that is, the electrode 34, and the same polarity electrode, that is, the electrode 31c.
  • the ink ejection system 120 includes the electrode 132 as shown in FIG. 8 when there is no problem in charging the ink 20a even when the ink 20a is not provided, such as when the ink 20a has conductivity. It does not have to be.
  • the charging electrode is the same polarity electrode, that is, the nozzle plate 131. Therefore, as shown in FIG. Compared to the same polarity electrode, that is, a configuration different from the nozzle plate 131, it can be realized with a simple configuration.
  • the ink ejection system 120 includes an electrode provided inside the pressure chamber 30a like the electrode 34 (see FIG. 3) or the electrode 132 (see FIG. 6). Therefore, an existing recording head can be used as the recording head 130 as it is. Therefore, the ink ejection system 120 can be realized at a low cost when it has the configuration shown in FIG.
  • the ink ejection system 120 may further replace the nozzle plate 131 with the nozzle plate 133 in the configuration shown in FIG. 8, as shown in FIG.
  • the nozzle plate 133 includes a plate main body 133a attached to the wall portion 32, and an electrode 133b provided on the surface of the plate main body 133a opposite to the wall portion 32 side.
  • the plate body 133a is made of an insulator such as insulating plastic.
  • the electrode 133b is an electrode that is charged to the same kind of polarity as the ink droplet 20b ejected from the nozzle 31a, and constitutes the same polarity electrode of the present invention. That is, the electrode 133b constitutes a pair of electrostatic field electrodes of the present invention together with the electrode 51.
  • the electrode 133b is an electrode for charging the ink 20a stored in the recording head 130, and constitutes the charging electrode of the present invention.
  • the charging electrode is the same polarity electrode, that is, the electrode 133b
  • a part of the charging electrode, that is, the electrode 132 is the same as shown in FIG.
  • it can be realized with a simple configuration.
  • the ink ejection system 120 includes an electrode provided inside the pressure chamber 30a like the electrode 34 (see FIG. 3) or the electrode 132 (see FIG. 6). Therefore, the existing recording head can be used as the recording head 130 as it is or simply by subjecting the nozzle plate to a conductive treatment. Therefore, the ink ejection system 120 can be realized at a low cost when it has the configuration shown in FIG.
  • FIG. 10 is a schematic view seen from the front of the ink ejection system 420 provided in the ink jet printer according to the third embodiment of the present invention.
  • the configuration of the ink jet printer according to the present embodiment is the same as the configuration in which the ink jet printer according to the second embodiment includes the ink discharge system 420 shown in FIG. 10 instead of the ink discharge system 120 (see FIG. 6). It is.
  • the configuration of the ink ejection system 420 is the same as the configuration provided in the ink ejection system 120 in place of the flight assist device 450 in place of the flight assist device 150 (see FIG. 6).
  • the configuration of the flight assist device 450 is the same as the configuration of the flight assist device 150 provided in place of the voltage application unit 151 (see FIG. 6) instead of the voltage application unit 451 that applies a voltage between the nozzle plate 131 and the electrode 51. is there.
  • FIG. 11 is a flowchart of the operation of the control unit 60 when one ink droplet 20b reaches the recording medium 90 from the nozzle 31a.
  • control unit 60 starts applying the voltage Vb to the nozzle plate 131 by the voltage application unit 451, and applies the voltage Vc between the electrode 35 and the electrode 36 by the driving voltage application unit 41. Apply (S471).
  • the flying assist device 450 charges the ink 20a inside the pressure chamber 30a, for example, positively by injection of charges from the nozzle plate 131 and the electrode 132 or polarization due to an electric field generated by the nozzle plate 131 and the electrode 132. Let Further, the flying assist device 450 generates an electrostatic field between the nozzle plate 131 and the electrode 51.
  • the ink extruding device 40 applies pressure to the ink 20a inside the pressure chamber 30a by the piezo element 33 when the piezo element 33 is deformed by the application of the voltage Vc.
  • pressure is applied to the ink 20a inside the pressure chamber 30a by the piezo element 33, one ink droplet 20b out of the ink 20a inside the pressure chamber 30a charged by the flying assist device 450 is ejected from the nozzle 31a.
  • the pressure that the ink extruding device 40 applies to the ink 20a is a pressure at which the ink droplet 20b can be ejected from the nozzle 31a only by the ink extruding device 40 of the ink extruding device 40 and the flight assisting device 450. That is, the voltage Vc is a voltage at which the ink droplet 20b can be ejected from the nozzle 31a only by the ink extruding device 40 of the ink extruding device 40 and the flight assisting device 450.
  • the voltage Vb for assisting the flying of the ink 20a is a voltage at which the ink droplet 20b cannot be ejected from the nozzle 31a only by the flying assisting device 450 of the ink extruding device 40 and the flying assisting device 450.
  • the pressure applied by the ink extruding device 40 to the ink 20a is less than the minimum size of the ink droplet 20b that can reach the recording medium 90 against the air resistance R when the flying assist device 450 does not assist the flight. Is the pressure at which the gas is discharged from the nozzle 31a. That is, the voltage Vc is a voltage that generates a small ink droplet 20b that cannot reach the recording medium 90 against the air resistance R when there is no flight assistance by the flight assist device 450.
  • the ink droplet 20b ejected from the nozzle 31a by the ink extruding device 40 is assisted by the electrostatic force generated by the flight assist device 450 in S471.
  • time from the execution of the process of S471 to the ejection of one ink droplet 20b from the nozzle 31a is equal to or longer than the time Ta according to the second embodiment.
  • the control unit 60 determines whether or not the time Tb has elapsed since the execution of the process of S471 until it is determined that the time Tb has elapsed since the execution of the process of S471. (S472). Is this time Tb the same as the total time of the time when the voltage Vc, which is a pulse voltage, is applied and the time until the ink droplet 20b ejected from the nozzle 31a reaches the recording medium 90? The time is slightly longer than the total time and is a preset time. The time until the ink droplet 20b ejected from the nozzle 31a reaches the recording medium 90 is acquired based on the flying speed of the ink droplet 20b and the distance between the nozzle 31a and the recording medium 90. Can do.
  • the control unit 60 can cause one ink droplet 20b to reach the recording medium 90 from the nozzle 31a by the operation shown in FIG. 11, but similarly, a plurality of ink droplets 20b are continuously provided from the nozzle 31a.
  • the recording medium 90 can be reached. That is, the control unit 60 generates the voltage Vb and the voltage Vc, which are pulse voltages, every time the ink droplet 20b is ejected from the nozzle 31a.
  • the ink ejection system 420 is configured such that the voltage Vb applied between the pair of electrostatic field electrodes, that is, the electrode 51 and the nozzle plate 131, causes the ink ejection device 40 to eject the ink droplet 20b from the nozzle 31a. Since the pulse voltage is wider than the voltage Vc that is the pulse voltage to be pushed out, safety can be improved as compared with a configuration in which a high voltage Vb is always applied between the electrode 51 and the nozzle plate 131.
  • the configuration of the recording head 130 may be the configuration shown in FIG. 8 or FIG.
  • FIG. 12 is a schematic view seen from the front of the ink ejection system 220 provided in the ink jet printer according to the fourth embodiment of the present invention.
  • the configuration of the ink jet printer according to the present embodiment is the same as the configuration in which the ink jet printer 10 (see FIG. 1) includes the ink discharge system 220 shown in FIG. 12 instead of the ink discharge system 20 (see FIG. 3). is there.
  • the configuration of the ink ejection system 220 is the same as the configuration provided in the ink ejection system 20 instead of the recording head 30 (see FIG. 3) and the flying assistance device 50 (see FIG. 3). It is.
  • the configuration of the recording head 230 includes a nozzle plate 231 that is an electrode as a whole and an electrode 232 that is electrically connected to the nozzle plate 231, a nozzle plate 31 (see FIG. 3), and an electrode 34 (see FIG. 3).
  • the recording head 30 has the same configuration as that shown in FIG.
  • the flight assist device 250 includes the nozzle plate 231 and the electrode 232 described above, the electrode 251 disposed on the recording head 230 side with respect to the recording medium 90, and the electrode disposed on the recording medium 90 side with respect to the electrode 251. 51, a charging voltage applying unit 52 that applies a voltage between the electrode 251 and the nozzle plate 231, and an electrostatic field voltage applying unit 53 that applies a voltage between the electrode 251 and the electrode 51.
  • the electrode 251 has a hole 251a through which the ink droplet 20b ejected from the nozzle 31a passes.
  • the nozzle plate 231 and the electrode 232 are electrodes for charging the ink 20a accommodated in the recording head 230, and constitute the charging electrode of the present invention.
  • the electrode 251 is an electrode that is charged to the same kind of polarity as the ink droplet 20b ejected from the nozzle 31a, and constitutes the same polarity electrode of the present invention. That is, the electrode 251 constitutes a pair of electrostatic field electrodes of the present invention together with the electrode 51.
  • the operation of the ink ejection system 220 is the same as the operation of the ink ejection system 20 according to the first embodiment, the description thereof is omitted.
  • the ink ejection system 220 can eject the ink droplet 20b from the nozzle 31a only by the ink extrusion device 40 of the ink extrusion device 40 and the flight assist device 250. Therefore, it is not necessary to generate a high-voltage electrostatic field by the flying assist device 250. Therefore, the ink ejection system 220 can mount the nozzles 31a on the recording head 230 at a higher density than the conventional one even if the necessary dielectric strength between the nozzles 31a in the recording head 230 is ensured. Can be faster.
  • the ink ejection system 220 causes the ink droplet 20b of a minute size that cannot reach the recording medium 90 against the air resistance R to reach the recording medium 90 when the flying assist device 250 does not assist the flight. Therefore, extremely thin lines can be printed on the recording medium 90.
  • the ink ejection system 220 can easily extend the flight distance of the ink droplet 20b by extending the distance between the electrode 251 and the electrode 51.
  • the ink ejection system 220 includes the electrode 232 as illustrated in FIG. 13 when there is no problem in charging the ink 20a even when the ink 20a is not provided, such as when the ink 20a has conductivity. It does not have to be.
  • the ink ejection system 220 does not include an electrode provided inside the pressure chamber 30a like the electrode 34 (see FIG. 3) or the electrode 232 (see FIG. 12). Therefore, an existing recording head can be employed as the recording head 230 as it is. Therefore, the ink ejection system 220 can be realized at a low cost when it has the configuration shown in FIG.
  • the ink ejection system 220 may further replace the nozzle plate 231 with the nozzle plate 233 in the configuration shown in FIG. 13 as shown in FIG. 14 when there is no problem in charging the ink 20a.
  • the nozzle plate 233 includes a plate body 233a attached to the wall portion 32, and an electrode 233b provided on the surface of the plate body 233a opposite to the wall portion 32 side.
  • the plate body 233a is made of an insulator such as insulating plastic.
  • the electrode 233b is an electrode for charging the ink 20a stored in the recording head 230, and constitutes the charging electrode of the present invention.
  • the ink ejection system 220 does not include an electrode provided inside the pressure chamber 30a like the electrode 34 (see FIG. 3) or the electrode 232 (see FIG. 12). Therefore, the existing recording head can be employed as the recording head 230 as it is or simply by conducting the conductive treatment on the nozzle plate. Therefore, the ink ejection system 220 can be realized at a low cost when it has the configuration shown in FIG.
  • FIG. 15 is a schematic view seen from the front of the ink ejection system 320 provided in the ink jet printer according to the fifth embodiment of the present invention.
  • the configuration of the ink jet printer according to the present embodiment is the same as the configuration in which the ink jet printer 10 (see FIG. 1) includes the ink discharge system 320 shown in FIG. 15 instead of the ink discharge system 20 (see FIG. 3). is there.
  • the configuration of the ink ejection system 320 includes a recording head 330, an ink extruding device 340, and a flight assisting device 350. Instead of the above, the configuration of the ink ejection system 20 is the same.
  • the ink 20a of the ink ejection system 320 is a conductive ink.
  • the recording head 330 includes a shear mode piezo element 331 attached to the nozzle plate 31, a wall 332 attached to the piezo element 331, an electrode 333 and an electrode 334 attached to the piezo element 331.
  • a wall 32 see FIG. 3
  • a piezo element 33 see FIG. 3
  • an electrode 34 see FIG. 3
  • an electrode 35 see FIG. 3
  • an electrode 36 see FIG. 3
  • the configuration of the recording head 30 is the same.
  • the wall portion 332 is made of an insulator such as insulating plastic.
  • the ink extruding device 340 includes the above-described piezo element 331, electrode 333, and electrode 334, and a voltage applying unit 341 that applies a voltage between the electrode 333 and the electrode 334.
  • the electrode 333 and the electrode 334 are electrodes for driving the ink extruding device 340.
  • the electrode 333 is provided inside the pressure chamber 30a and constitutes the pressure chamber driving electrode of the present invention.
  • the flight assist device 350 includes an electrode 31c of the nozzle plate 31, an electrode 51, an electrode 333 and an electrode 334, a voltage application unit 341, and a voltage application unit 351 that applies a voltage.
  • the voltage application unit 351 applies a voltage between the electrode 31 c and the electrode 334 and the electrode 51.
  • the electrode 333 is an electrode for charging the ink 20a stored in the recording head 330, and constitutes the charging electrode of the present invention.
  • the control unit 60 applies the voltage Vc between the electrode 333 and the electrode 334 by the voltage application unit 341. Accordingly, the flying assist device 350 charges the ink 20a inside the pressure chamber 30a positively, for example, by injecting charges from the electrode 333. Further, the ink extruding device 340 applies pressure to the ink 20a inside the pressure chamber 30a by the piezo element 331 when the piezo element 331 is deformed by the application of the voltage Vc. When pressure is applied to the ink 20a inside the pressure chamber 30a by the piezo element 331, one ink droplet 20b out of the charged ink 20a inside the pressure chamber 30a is ejected from the nozzle 31a.
  • the ink ejection system 320 can eject the ink droplet 20b from the nozzle 31a only by the ink extrusion device 340 out of the ink extrusion device 340 and the flight assisting device 350. Therefore, it is not necessary to generate a high-voltage electrostatic field by the flying assist device 350. Therefore, the ink ejection system 320 can mount the nozzles 31a on the recording head 330 at a higher density than the conventional one even if the necessary withstand voltage between the nozzles 31a in the recording head 330 is ensured. Can be faster.
  • the ink ejection system 320 causes the ink droplets 20b of minute size that cannot reach the recording medium 90 against the air resistance R to reach the recording medium 90 when there is no flying assistance by the flying assistance device 350. Therefore, extremely thin lines can be printed on the recording medium 90.
  • the ink ejection system 320 can easily extend the flight distance of the ink droplet 20b by extending the distance between the electrode 31c and the electrode 51.
  • the electrode 31c that is the same polarity electrode constitutes a part of the nozzle plate 31 that is a member in which the nozzle 31a is formed in the recording head 330, the recording head 330, Compared to a configuration in which the same polarity electrodes are provided separately, the configuration can be realized with a simple configuration.
  • the charging electrode is the pressure chamber driving electrode, that is, the electrode 333, compared with the configuration in which the charging electrode and the pressure chamber driving electrode are separately provided, It can be realized with a simple configuration.
  • the ink ejection system 320 can be used as the recording head 330 as it is, with an existing recording head provided with an electrode for driving in the pressure chamber as it is or simply by conducting a conductive treatment on the nozzle plate. Therefore, the ink ejection system 320 can be realized at a low cost.
  • the flight assist device in the ink jet printer according to each of the above-described embodiments charges the ink positively, it may be negatively charged.
  • the direction of the electrostatic field is also opposite to the direction in each of the above-described embodiments.
  • the ink extrusion device in the ink jet printer according to each of the above-described embodiments is a device that pushes ink droplets out of the nozzles by applying pressure to the ink with a shear mode piezo element.
  • the ink extrusion device in the ink jet printer according to each of the above-described embodiments may be a device that pushes ink droplets out of the nozzles by applying pressure to the ink with a piezo element in a mode other than the share mode.
  • the piezo element of the ink extrusion apparatus in the ink jet printer may be a flexure mode piezo element, a longitudinal mode piezo element, a transverse mode piezo element, or the like.
  • the ink extrusion device in the ink jet printer according to each of the above-described embodiments is a device that pushes ink droplets out of the nozzles by applying pressure to the ink with a piezo element.
  • the ink extrusion device in the ink jet printer according to each of the above-described embodiments may be a device that pushes ink droplets out of the nozzles by applying pressure to the ink with a configuration other than the piezo element.
  • the ink extruding device in the ink jet printer includes a thermal jet (bubble jet (registered) that pushes ink droplets out of the nozzles by applying pressure to the ink by bubbles generated in the ink by heating the ink. Trademark)) type apparatus.
  • thermal jet bubble jet (registered) that pushes ink droplets out of the nozzles by applying pressure to the ink by bubbles generated in the ink by heating the ink. Trademark) type apparatus.
  • the ink jet printer in each of the above-described embodiments moves the recording head in the main scanning direction by the carriage 11b with respect to the recording medium 90 that does not move in the main scanning direction.
  • the position of the recording head in the sub-scanning direction relative to the recording medium 90 is set in the printing in the main scanning direction.
  • the ink jet printer may be a printer of a method other than the methods in the above-described embodiments.
  • the inkjet printer causes the recording head 90 to perform printing in the main scanning direction by moving the recording head in the main scanning direction by the carriage 11b with respect to the recording medium 90 that is placed on the table and does not move.
  • An ink jet printer that changes the position of the recording head in the sub-scanning direction relative to the recording medium 90 by moving the main body 11 in the sub-scanning direction with respect to the mounted table every time printing in the main scanning direction is completed. There may be.
  • Ink Discharge System 20a Ink 20b Ink Drop (Ink Particles) 30 recording head 30a pressure chamber 31a nozzle 31c electrode (electrostatic field electrode, same polarity electrode) 34 Electrodes (charging electrodes) 40 Ink Extruder 50 Flying Auxiliary Device 51 Electrode (Electrostatic Electrode, Electropolar Electrode) 60 Control unit 90 Recording medium 120 Ink ejection system 130 Recording head 131 Nozzle plate (charging electrode, electrostatic field electrode, same polarity electrode) 132 electrode (charging electrode) 133b Electrode (charging electrode, electrostatic field electrode, same polarity electrode) 150 flying assist device 220 ink discharge system 230 recording head 231 nozzle plate (charging electrode) 232 electrode (charging electrode) 233b Electrode (charging electrode) 250 Flying assistance device 251 Electrode (Electrostatic field electrode, same polarity electrode) 320 Ink ejection system 330 Recording head 333 Electrode (charging electrode, pressure chamber driving electrode) 340 Ink Ex

Abstract

The problem addressed by the present invention is to provide an ink discharging system that can cause printing speed to be more rapid than conventional printing speeds. To solve the problem, the present invention is characterized in that the control unit of the ink discharging system (20) causes ink (20a) housed in a recording head (30) to be electrostatically charged by means of a flight assistance device (50), causes ink droplets (20b) of the ink (20a) electrostatically charged by means of the flight assistance device (50) to be discharged from a nozzle (31a) by means of an ink extrusion device (40), and causes the flight of the ink droplets (20b) discharged from the nozzle (31a) by means of the ink extrusion device (40) to be assisted by the flight assistance device (50) by means of electrostatic force. The present invention is further characterized in that the pressure that the ink extrusion device (40) applies to the ink (20a) is a pressure such that ink droplets (20b) can be discharged from the nozzle (31a) by only the ink extrusion device (40) among the ink extrusion device (40) and the flight assistance device (50), and is a pressure such that the ink droplets (20b) are discharged from the nozzle (31a) at less than the smallest size that can reach a recording medium (90) against air resistance in the case that the flight assistance resulting from the flight assistance device (50) is absent.

Description

インク吐出システムInk ejection system
　本発明は、用紙などの記録媒体に向けてインクの粒を吐出するインク吐出システムに関する。 The present invention relates to an ink ejection system that ejects ink particles toward a recording medium such as paper.
　従来のインク吐出システムとして、インクの粒を吐出するためのノズルを複数備えている記録ヘッドと、記録ヘッドに収納されているインクに圧力を加えることによってインクをノズルから押し出すインク押出装置と、インクの粒の飛翔を静電力によって補助する飛翔補助装置とを備えているものが知られている（特許文献１参照。）。このインク吐出システムは、インク押出装置によるインクの押し出しと、飛翔補助装置によるインクの静電吸引との併用によってインクの粒を吐出することができる。したがって、このインク吐出システムは、インク押出装置によるインクの押し出しのみによってインクの粒を吐出する構成と比較して、インク押出装置の消費電力を抑えることができる。 As a conventional ink ejection system, a recording head having a plurality of nozzles for ejecting ink particles, an ink extruding device that pushes ink out of the nozzles by applying pressure to the ink stored in the recording head, and an ink There is known a device equipped with a flight assist device that assists the flight of the particles with electrostatic force (see Patent Document 1). This ink ejection system can eject ink particles by a combination of ink ejection by an ink extruding device and electrostatic attraction of ink by a flight assist device. Therefore, this ink ejection system can suppress the power consumption of the ink extruding device as compared with the configuration in which the ink particles are ejected only by the extrusion of the ink by the ink extruding device.
特開平８－１３２６２１号公報JP-A-8-132621
　しかしながら、従来のインク吐出システムにおいては、インク押出装置によるインクの押し出しだけでなく、飛翔補助装置によるインクの静電吸引によってもインクの粒を吐出するので、インクの粒の吐出のために飛翔補助装置によって例えば１．５ｋＶ程度という高圧の静電界を発生させる必要がある。このため、従来のインク吐出システムにおいては、記録ヘッドにおけるノズル間の絶縁耐圧を確保する必要があるので、記録ヘッドに高密度でノズルを実装することが困難であるという問題がある。インク吐出システムは、記録ヘッドにおけるノズルの実装の密度が低い場合、単位時間当たりに吐出することができるインクの粒の数が少ないので、印刷速度が遅くなる。 However, in the conventional ink ejection system, ink particles are ejected not only by the ink extrusion by the ink extrusion device but also by the electrostatic suction of the ink by the flight assist device. It is necessary to generate a high-voltage electrostatic field of about 1.5 kV, for example, depending on the apparatus. For this reason, the conventional ink ejection system has a problem that it is difficult to mount the nozzles on the recording head at a high density because it is necessary to ensure the dielectric strength between the nozzles in the recording head. In the ink ejection system, when the nozzle mounting density in the recording head is low, the number of ink particles that can be ejected per unit time is small, and thus the printing speed is slow.
　そこで、本発明は、ノズルの実装の密度を上げることによって印刷速度を従来より速くすることができるインク吐出システムを提供することを目的とする。 Therefore, an object of the present invention is to provide an ink ejection system capable of increasing the printing speed by increasing the density of nozzle mounting.
　本発明のインク吐出システムは、記録媒体に向けてインクの粒を吐出するためのノズルを複数備えている記録ヘッドと、前記記録ヘッドに収納されている前記インクに圧力を加えることによって前記インクの前記粒を前記ノズルから押し出すインク押出装置と、前記粒の飛翔を静電力によって補助する飛翔補助装置と、前記インク押出装置および前記飛翔補助装置の動作を制御する制御部とを備えており、前記制御部は、前記記録ヘッドに収納されている前記インクを前記飛翔補助装置に帯電させ、前記飛翔補助装置によって帯電させられた前記インクの前記粒を前記インク押出装置によって前記ノズルから吐出させ、前記インク押出装置によって前記ノズルから吐出させられた前記粒の飛翔を前記静電力によって前記飛翔補助装置に補助させ、前記インク押出装置が前記インクに加える前記圧力は、前記インク押出装置および前記飛翔補助装置のうち前記インク押出装置のみで前記粒を前記ノズルから吐出することができる圧力であって、前記飛翔補助装置による飛翔の補助が無い場合に空気抵抗に抗って前記記録媒体に到達することができる最小のサイズ未満の前記粒を前記ノズルから吐出する圧力であることを特徴とする。 An ink ejection system according to the present invention includes a recording head having a plurality of nozzles for ejecting ink particles toward a recording medium, and applying pressure to the ink stored in the recording head, An ink extruding device that extrudes the particles from the nozzle, a flying assist device that assists the flying of the particles by electrostatic force, and a controller that controls operations of the ink extruding device and the flying assist device, The control unit charges the flying auxiliary device with the ink stored in the recording head, causes the ink extrusion device to discharge the particles of the ink charged by the flying auxiliary device from the nozzle, and The flying assist device is assisted by the electrostatic force to fly the particles ejected from the nozzle by an ink extrusion device. The pressure applied to the ink by the ink extruding device is a pressure at which the ink can be ejected from the nozzle only by the ink extruding device of the ink extruding device and the flight assisting device, and the flying The pressure is such that the particles having a size less than the minimum size that can reach the recording medium against air resistance when the auxiliary device does not assist the flight are discharged from the nozzle.
　この構成により、本発明のインク吐出システムは、インク押出装置および飛翔補助装置のうちインク押出装置のみでインクの粒をノズルから吐出することができるので、インクの粒の吐出のために飛翔補助装置によって高圧の静電界を発生させる必要がない。したがって、本発明のインク吐出システムは、記録ヘッドにおけるノズル間の必要な絶縁耐圧を確保しても記録ヘッドに従来より高密度でノズルを実装することができ、その結果、印刷速度を従来より速くすることができる。 With this configuration, the ink ejection system according to the present invention can eject the ink particles from the nozzle only by the ink extrusion device of the ink extrusion device and the flight assist device. Therefore, it is not necessary to generate a high-voltage electrostatic field. Therefore, the ink ejection system of the present invention can mount the nozzles on the recording head at a higher density than before even if the necessary dielectric strength between the nozzles in the recording head is ensured. can do.
　また、本発明のインク吐出システムにおいて、前記飛翔補助装置は、前記記録ヘッドに収納されている前記インクを帯電させる帯電用電極と、前記ノズルから吐出させられた前記粒に前記静電力を与える静電界を発生させる一対の静電界用電極とを備えており、前記一対の静電界用電極は、前記ノズルから吐出させられる前記粒と同種の極性に帯電させられる同極性電極と、前記ノズルから吐出させられる前記粒と異種の極性に帯電させられる異極性電極とによって構成されており、前記同極性電極は、前記記録媒体に対して前記記録ヘッド側に配置されており、前記異極性電極は、前記同極性電極に対して前記記録媒体側に配置されていても良い。 In the ink ejection system according to the aspect of the invention, the flying assist device may include a charging electrode that charges the ink stored in the recording head and an electrostatic force that applies the electrostatic force to the particles ejected from the nozzle. A pair of electrostatic field electrodes for generating an electric field, the pair of electrostatic field electrodes being discharged from the nozzle with the same polarity electrode charged to the same kind of polarity as the particles discharged from the nozzle And the different polarity electrodes that are charged to different polarities, the same polarity electrodes are disposed on the recording head side with respect to the recording medium, and the different polarity electrodes are: It may be disposed on the recording medium side with respect to the same polarity electrode.
　この構成により、本発明のインク吐出システムは、同極性電極と、異極性電極との間の距離を延長することによって、インクの粒の飛翔距離を容易に延長することができる。 With this configuration, the ink ejection system of the present invention can easily extend the flying distance of the ink particles by extending the distance between the same polarity electrode and the different polarity electrode.
　また、本発明のインク吐出システムにおいて、前記同極性電極は、前記記録ヘッドのうち前記ノズルが形成されている部材の少なくとも一部を構成していても良い。 In the ink ejection system of the present invention, the same polarity electrode may constitute at least a part of a member of the recording head where the nozzle is formed.
　この構成により、本発明のインク吐出システムは、記録ヘッドと、同極性電極とが別々に設けられている構成と比較して、簡単な構成で実現されることができる。 With this configuration, the ink ejection system of the present invention can be realized with a simple configuration as compared with the configuration in which the recording head and the same polarity electrode are separately provided.
　また、本発明のインク吐出システムにおいて、前記帯電用電極は、前記同極性電極の少なくとも一部を備えていても良い。 In the ink ejection system of the present invention, the charging electrode may include at least a part of the same polarity electrode.
　この構成により、本発明のインク吐出システムは、帯電用電極と、同極性電極とが別々に設けられている構成と比較して、簡単な構成で実現されることができる。 With this configuration, the ink ejection system of the present invention can be realized with a simple configuration as compared with the configuration in which the charging electrode and the same polarity electrode are separately provided.
　また、本発明のインク吐出システムにおいて、前記帯電用電極は、前記同極性電極であっても良い。 In the ink ejection system of the present invention, the charging electrode may be the same polarity electrode.
　この構成により、本発明のインク吐出システムは、帯電用電極の少なくとも一部が同極性電極と別である構成と比較して、簡単な構成で実現されることができる。 With this configuration, the ink ejection system of the present invention can be realized with a simple configuration as compared with a configuration in which at least a part of the charging electrode is different from the same polarity electrode.
　また、本発明のインク吐出システムにおいて、前記一対の静電界用電極の間に印加される電圧は、前記インク押出装置に前記インクの前記粒を前記ノズルから押し出させるパルス電圧より幅が広いパルス電圧であっても良い。 In the ink ejection system of the present invention, the voltage applied between the pair of electrostatic field electrodes is a pulse voltage having a width wider than a pulse voltage for causing the ink extruding device to extrude the particles of the ink from the nozzle. It may be.
　この構成により、本発明のインク吐出システムは、一対の静電界用電極の間に高い電圧を常に印加する構成と比較して、安全性を向上することができる。 With this configuration, the ink ejection system of the present invention can improve safety compared to a configuration in which a high voltage is always applied between a pair of electrostatic field electrodes.
　また、本発明のインク吐出システムにおいて、前記記録ヘッドは、収納している前記インクに前記インク押出装置によって前記圧力が加えられる圧力室が形成されており、前記インク押出装置は、前記インク押出装置自身の駆動用の電極であって前記圧力室の内部に設けられている圧力室内駆動用電極を備えており、前記帯電用電極は、前記圧力室内駆動用電極の少なくとも一部を備えていても良い。 In the ink ejection system of the present invention, the recording head is formed with a pressure chamber in which the pressure is applied to the stored ink by the ink pushing device, and the ink pushing device is the ink pushing device. A pressure chamber drive electrode provided inside the pressure chamber, and the charging electrode may include at least a part of the pressure chamber drive electrode. good.
　この構成により、本発明のインク吐出システムは、帯電用電極と、圧力室内駆動用電極とが別々に設けられている構成と比較して、簡単な構成で実現されることができる。 With this configuration, the ink ejection system of the present invention can be realized with a simple configuration as compared with the configuration in which the charging electrode and the pressure chamber driving electrode are separately provided.
　本発明のインク吐出システムは、ノズルの実装の密度を上げることによって印刷速度を従来より速くすることができる。 The ink ejection system of the present invention can increase the printing speed by increasing the density of nozzle mounting.
本発明の第１の実施の形態に係るインクジェットプリンターの斜視図である。1 is a perspective view of an ink jet printer according to a first embodiment of the present invention. 図１に示すインクジェットプリンターのキャリッジに搭載されている記録ヘッドの底面図である。FIG. 2 is a bottom view of a recording head mounted on a carriage of the ink jet printer shown in FIG. 1. 図１に示すインクジェットプリンターに備えられているインク吐出システムの正面から見た模式図である。It is the schematic diagram seen from the front of the ink discharge system with which the inkjet printer shown in FIG. 1 is equipped. 図３に示すインク吐出システムの各電圧印加部および制御部を示す図である。It is a figure which shows each voltage application part and control part of the ink discharge system shown in FIG. ノズルから１粒のインク滴を記録媒体に到達させる場合の図４に示す制御部の動作のフローチャートである。FIG. 5 is a flowchart of the operation of the control unit shown in FIG. 4 when one ink droplet from a nozzle reaches a recording medium. 本発明の第２の実施の形態に係るインクジェットプリンターに備えられているインク吐出システムの正面から見た模式図である。It is the schematic diagram seen from the front of the ink discharge system with which the inkjet printer which concerns on the 2nd Embodiment of this invention is equipped. ノズルから１粒のインク滴を記録媒体に到達させる場合の図６に示すインク吐出システムの制御部の動作のフローチャートである。FIG. 7 is a flowchart of the operation of the control unit of the ink ejection system shown in FIG. 6 when one ink droplet from a nozzle reaches the recording medium. 本発明の第２の実施の形態に係るインクジェットプリンターに備えられているインク吐出システムの正面から見た模式図であって、図６に示す例とは異なる例の図である。It is the schematic diagram seen from the front of the ink discharge system with which the inkjet printer which concerns on the 2nd Embodiment of this invention is equipped, Comprising: It is a figure of the example different from the example shown in FIG. 本発明の第２の実施の形態に係るインクジェットプリンターに備えられているインク吐出システムの正面から見た模式図であって、図６または図８に示す例とは異なる例の図である。It is the schematic diagram seen from the front of the ink discharge system with which the inkjet printer which concerns on the 2nd Embodiment of this invention is equipped, Comprising: It is a figure of an example different from the example shown in FIG. 本発明の第３の実施の形態に係るインクジェットプリンターに備えられているインク吐出システムの正面から見た模式図である。It is the schematic diagram seen from the front of the ink discharge system with which the inkjet printer which concerns on the 3rd Embodiment of this invention is equipped. ノズルから１粒のインク滴を記録媒体に到達させる場合の図１０に示すインク吐出システムの制御部の動作のフローチャートである。FIG. 11 is a flowchart of the operation of the control unit of the ink ejection system shown in FIG. 10 in a case where one droplet of ink reaches a recording medium from a nozzle. 本発明の第４の実施の形態に係るインクジェットプリンターに備えられているインク吐出システムの正面から見た模式図である。It is the schematic diagram seen from the front of the ink discharge system with which the inkjet printer which concerns on the 4th Embodiment of this invention is equipped. 本発明の第４の実施の形態に係るインクジェットプリンターに備えられているインク吐出システムの正面から見た模式図であって、図１２に示す例とは異なる例の図である。It is the schematic diagram seen from the front of the ink discharge system with which the inkjet printer which concerns on the 4th Embodiment of this invention is equipped, Comprising: It is a figure of the example different from the example shown in FIG. 本発明の第４の実施の形態に係るインクジェットプリンターに備えられているインク吐出システムの正面から見た模式図であって、図１２または図１３に示す例とは異なる例の図である。It is the schematic diagram seen from the front of the ink discharge system with which the inkjet printer which concerns on the 4th Embodiment of this invention is equipped, Comprising: It is a figure of an example different from the example shown in FIG. 本発明の第５の実施の形態に係るインクジェットプリンターに備えられているインク吐出システムの正面から見た模式図である。It is the schematic diagram seen from the front of the ink discharge system with which the inkjet printer which concerns on the 5th Embodiment of this invention is equipped.
　以下、本発明の実施の形態について、図面を用いて説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
　（第１の実施の形態）
　まず、本実施の形態に係るインクジェットプリンターの構成について説明する。 (First embodiment)
First, the configuration of the ink jet printer according to the present embodiment will be described.
　図１は、本実施の形態に係るインクジェットプリンター１０の斜視図である。 FIG. 1 is a perspective view of an ink jet printer 10 according to the present embodiment.
　図１に示すように、インクジェットプリンター１０は、矢印１０ａで示す主走査方向に延在する本体１１と、用紙などの記録媒体９０を搬送する搬送装置１２とを備えている。 As shown in FIG. 1, the inkjet printer 10 includes a main body 11 extending in the main scanning direction indicated by an arrow 10a, and a transport device 12 that transports a recording medium 90 such as paper.
　本体１１は、矢印１０ａで示す主走査方向に延在しているガイドレール１１ａと、矢印１０ａで示す主走査方向に移動可能にガイドレール１１ａに支持されているキャリッジ１１ｂとを備えている。 The main body 11 includes a guide rail 11a extending in the main scanning direction indicated by an arrow 10a, and a carriage 11b supported by the guide rail 11a so as to be movable in the main scanning direction indicated by the arrow 10a.
　搬送装置１２は、本体１１の後述の記録ヘッド３０に対して矢印１０ｂで示す副走査方向に記録媒体９０を搬送する装置である。 The conveying device 12 is a device that conveys the recording medium 90 in a sub-scanning direction indicated by an arrow 10b with respect to a recording head 30 described later of the main body 11.
　図２は、キャリッジ１１ｂに搭載されている記録ヘッド３０の底面図である。 FIG. 2 is a bottom view of the recording head 30 mounted on the carriage 11b.
　図２に示すように、記録ヘッド３０は、記録媒体９０（図１参照。）に向けてインクの粒（以下「インク滴」と言う。）を吐出するためのノズル３１ａを複数備えているノズルプレート３１を備えている。記録ヘッド３０は、オンデマンド型のインクジェットヘッドである。 As shown in FIG. 2, the recording head 30 includes a plurality of nozzles 31a for ejecting ink particles (hereinafter referred to as “ink droplets”) toward a recording medium 90 (see FIG. 1). A plate 31 is provided. The recording head 30 is an on-demand ink jet head.
　図３は、インクジェットプリンター１０に備えられているインク吐出システム２０の正面から見た模式図である。 FIG. 3 is a schematic view seen from the front of the ink ejection system 20 provided in the inkjet printer 10.
　なお、図３においては、インク吐出システム２０に対する理解を容易にするために、記録ヘッド３０の複数のノズル３１ａのうち１つのノズル３１ａが描かれている。しかしながら、実際には、インク吐出システム２０には、記録ヘッド３０の全てのノズル３１ａが含まれている。 In FIG. 3, one nozzle 31 a among the plurality of nozzles 31 a of the recording head 30 is drawn in order to facilitate understanding of the ink ejection system 20. However, in practice, the ink ejection system 20 includes all the nozzles 31 a of the recording head 30.
　図３に示すように、インク吐出システム２０は、上述の記録ヘッド３０と、記録ヘッド３０に収納されているインク２０ａに圧力を加えることによってインク滴２０ｂをノズル３１ａから押し出すインク押出装置４０と、インク滴２０ｂの飛翔を静電力によって補助する飛翔補助装置５０とを備えている。 As shown in FIG. 3, the ink ejection system 20 includes the above-described recording head 30, an ink extrusion device 40 that pushes the ink droplet 20 b from the nozzle 31 a by applying pressure to the ink 20 a stored in the recording head 30, and And a flight assist device 50 that assists the flight of the ink droplet 20b with an electrostatic force.
　記録ヘッド３０は、上述のノズルプレート３１と、ノズルプレート３１に取り付けられている壁部３２と、壁部３２に取り付けられているシェアモードのピエゾ素子３３と、壁部３２に取り付けられている電極３４と、ピエゾ素子３３に取り付けられている電極３５および電極３６とを備えている。 The recording head 30 includes the above-described nozzle plate 31, a wall portion 32 attached to the nozzle plate 31, a shear mode piezo element 33 attached to the wall portion 32, and an electrode attached to the wall portion 32. 34, and an electrode 35 and an electrode 36 attached to the piezo element 33.
　ノズルプレート３１、壁部３２およびピエゾ素子３３は、収納しているインク２０ａにインク押出装置４０によって圧力が加えられる圧力室３０ａを形成している。圧力室３０ａは、インク２０ａの図示していない供給路が連通されており、ノズル３１ａからインク滴２０ｂが吐出される度に、新たなインク２０ａがこの供給路から供給されるようになっている。 The nozzle plate 31, the wall portion 32, and the piezo element 33 form a pressure chamber 30a in which pressure is applied to the stored ink 20a by the ink extruding device 40. The pressure chamber 30a is connected to a supply path (not shown) for the ink 20a, and new ink 20a is supplied from the supply path each time an ink droplet 20b is ejected from the nozzle 31a. .
　なお、圧力室３０ａは、インク吐出システム２０に対する理解を容易にするために、図３において、記録ヘッド３０の正面側に現れている。しかしながら、実際には、圧力室３０ａは、記録ヘッド３０の正面側において壁部３２によって覆われており、記録ヘッド３０の正面側に現れていない。同様に、ノズル３１ａの内部の空間は、インク吐出システム２０に対する理解を容易にするために、図３において、記録ヘッド３０の正面側に現れている。しかしながら、実際には、ノズル３１ａの内部の空間は、記録ヘッド３０の正面側においてノズルプレート３１によって覆われており、記録ヘッド３０の正面側に現れていない。 Note that the pressure chamber 30 a appears on the front side of the recording head 30 in FIG. 3 in order to facilitate understanding of the ink ejection system 20. However, actually, the pressure chamber 30 a is covered by the wall portion 32 on the front side of the recording head 30 and does not appear on the front side of the recording head 30. Similarly, the space inside the nozzle 31 a appears on the front side of the recording head 30 in FIG. 3 in order to facilitate understanding of the ink ejection system 20. However, actually, the space inside the nozzle 31 a is covered with the nozzle plate 31 on the front side of the recording head 30, and does not appear on the front side of the recording head 30.
　ノズルプレート３１は、壁部３２に取り付けられているプレート本体３１ｂと、プレート本体３１ｂのうち壁部３２側とは反対側の表面に設けられている電極３１ｃとを備えている。 The nozzle plate 31 includes a plate body 31b attached to the wall portion 32, and an electrode 31c provided on the surface of the plate body 31b opposite to the wall portion 32 side.
　電極３４は、圧力室３０ａの内部に設けられている。 The electrode 34 is provided inside the pressure chamber 30a.
　プレート本体３１ｂおよび壁部３２は、例えば絶縁性のプラスチックなどの絶縁体によって構成されている。 The plate body 31b and the wall 32 are made of an insulator such as insulating plastic.
　インク押出装置４０は、上述のピエゾ素子３３、電極３５および電極３６と、電極３５および電極３６の間に電圧を印加する駆動用電圧印加部４１とを備えている。 The ink extruding device 40 includes the piezoelectric element 33, the electrode 35, and the electrode 36 described above, and a driving voltage applying unit 41 that applies a voltage between the electrode 35 and the electrode 36.
　電極３５および電極３６は、インク押出装置４０の駆動用の電極である。 The electrode 35 and the electrode 36 are electrodes for driving the ink extruding device 40.
　飛翔補助装置５０は、上述の電極３１ｃおよび電極３４と、電極３１ｃに対して記録媒体９０側に配置されている電極５１と、電極３１ｃおよび電極３４の間に電圧を印加する帯電用電圧印加部５２と、電極３１ｃおよび電極５１の間に電圧を印加する静電界用電圧印加部５３とを備えている。 The flying assist device 50 includes the above-described electrode 31c and electrode 34, an electrode 51 disposed on the recording medium 90 side with respect to the electrode 31c, and a charging voltage application unit that applies a voltage between the electrode 31c and the electrode 34. 52 and an electrostatic field voltage application unit 53 for applying a voltage between the electrode 31c and the electrode 51.
　電極３１ｃは、記録媒体９０に対して記録ヘッド３０側に配置されている。 The electrode 31c is disposed on the recording head 30 side with respect to the recording medium 90.
　ここで、電極３４は、記録ヘッド３０に収納されているインク２０ａを帯電させる電極であり、本発明の帯電用電極を構成している。 Here, the electrode 34 is an electrode for charging the ink 20a accommodated in the recording head 30, and constitutes the charging electrode of the present invention.
　また、電極３１ｃは、ノズル３１ａから吐出させられるインク滴２０ｂと同種の極性に帯電させられる電極であり、本発明の同極性電極を構成している。一方、電極５１は、ノズル３１ａから吐出させられるインク滴２０ｂと異種の極性に帯電させられる電極であり、本発明の異極性電極を構成している。すなわち、電極３１ｃおよび電極５１は、ノズル３１ａから吐出させられたインク滴２０ｂに静電力を与える静電界を発生させるようになっており、本発明の一対の静電界用電極を構成している。 The electrode 31c is an electrode that is charged to the same kind of polarity as the ink droplet 20b ejected from the nozzle 31a, and constitutes the same polarity electrode of the present invention. On the other hand, the electrode 51 is an electrode that is charged to a polarity different from that of the ink droplet 20b ejected from the nozzle 31a, and constitutes a different polarity electrode of the present invention. That is, the electrode 31c and the electrode 51 generate an electrostatic field that gives an electrostatic force to the ink droplet 20b ejected from the nozzle 31a, and constitute a pair of electrostatic field electrodes of the present invention.
　図４は、インク吐出システム２０の各電圧印加部および制御部６０を示す図である。 FIG. 4 is a diagram showing each voltage application unit and the control unit 60 of the ink ejection system 20.
　インク吐出システム２０は、図４に示す制御部６０を備えている。 The ink ejection system 20 includes a control unit 60 shown in FIG.
　制御部６０は、例えば、ＣＰＵ（Ｃｅｎｔｒａｌ　Ｐｒｏｃｅｓｓｉｎｇ　Ｕｎｉｔ）と、プログラムおよび各種のデータを予め記憶しているＲＯＭ（Ｒｅａｄ　Ｏｎｌｙ　Ｍｅｍｏｒｙ）と、ＣＰＵの作業領域として用いられるＲＡＭ（Ｒａｎｄｏｍ　Ａｃｃｅｓｓ　Ｍｅｍｏｒｙ）とを備えている。ＣＰＵは、ＲＯＭに記憶されているプログラムを実行するようになっている。 The control unit 60 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores programs and various data in advance, and a RAM (Random Access Memory) used as a work area of the CPU. ing. The CPU executes a program stored in the ROM.
　制御部６０は、駆動用電圧印加部４１を制御することによって、インク押出装置４０（図３参照。）の動作を制御することが可能である。 The control unit 60 can control the operation of the ink extruding device 40 (see FIG. 3) by controlling the driving voltage applying unit 41.
　制御部６０は、帯電用電圧印加部５２および静電界用電圧印加部５３を制御することによって、飛翔補助装置５０（図３参照。）の動作を制御することが可能である。 The control unit 60 can control the operation of the flight assist device 50 (see FIG. 3) by controlling the charging voltage application unit 52 and the electrostatic field voltage application unit 53.
　次に、インク吐出システム２０の動作について説明する。 Next, the operation of the ink ejection system 20 will be described.
　図５は、ノズル３１ａから１粒のインク滴２０ｂを記録媒体９０に到達させる場合の制御部６０の動作のフローチャートである。 FIG. 5 is a flowchart of the operation of the control unit 60 when one ink droplet 20b reaches the recording medium 90 from the nozzle 31a.
　図５に示すように、制御部６０は、帯電用電圧印加部５２によって電極３１ｃおよび電極３４の間に、時間Ｔａの間、電圧Ｖａを印加する（Ｓ７１）。したがって、飛翔補助装置５０は、圧力室３０ａの内部のインク２０ａを、電極３４からの電荷の注入、または、電極３４によって生じた電界による分極によって、例えば正に帯電させる。 As shown in FIG. 5, the control unit 60 applies the voltage Va between the electrode 31c and the electrode 34 by the charging voltage application unit 52 for a time Ta (S71). Therefore, the flying assist device 50 charges the ink 20a inside the pressure chamber 30a positively, for example, by injection of electric charge from the electrode 34 or polarization due to the electric field generated by the electrode 34.
　なお、時間Ｔａは、インク２０ａの誘電緩和時間τ以上の時間である。ここで、誘電緩和時間τは、真空の誘電率ε０と、インク２０ａの比誘電率εｒと、インク２０ａの比抵抗ρとに基づいて、数１のように表される。例えば、時間Ｔａが０．０１ｍｓである場合、インク２０ａは、比抵抗ρが約１０７Ωｃｍ以下、好ましくは１０６Ωｃｍ以下のインクであれば良い。
Figure JPOXMLDOC01-appb-M000001
 The time Ta is a time longer than the dielectric relaxation time τ of the ink 20a. Here, the dielectric relaxation time τ is expressed by Equation 1 based on the dielectric constant ε 0 of vacuum, the relative dielectric constant ε r of the ink 20a, and the specific resistance ρ of the ink 20a. For example, when the time Ta is 0.01 ms, the ink 20a may be an ink having a specific resistance ρ of about 10 7 Ωcm or less, preferably 10 6 Ωcm or less.
Figure JPOXMLDOC01-appb-M000001
　制御部６０は、Ｓ７１の処理の後、静電界用電圧印加部５３によって電極３１ｃおよび電極５１の間に電圧Ｖｂを印加することを開始する（Ｓ７２）。したがって、飛翔補助装置５０は、電極３１ｃおよび電極５１の間に静電界を生成する。 The control unit 60 starts applying the voltage Vb between the electrode 31c and the electrode 51 by the electrostatic field voltage applying unit 53 after the processing of S71 (S72). Therefore, the flying assist device 50 generates an electrostatic field between the electrode 31 c and the electrode 51.
　制御部６０は、Ｓ７２の処理の後、駆動用電圧印加部４１によって電極３５および電極３６の間に電圧Ｖｃを印加する（Ｓ７３）。したがって、インク押出装置４０は、電圧Ｖｃの印加によってピエゾ素子３３が変形することによって、圧力室３０ａの内部のインク２０ａにピエゾ素子３３によって圧力を加える。圧力室３０ａの内部のインク２０ａにピエゾ素子３３によって圧力が加えられると、Ｓ７１において帯電させられた圧力室３０ａの内部のインク２０ａのうち１粒のインク滴２０ｂがノズル３１ａから吐出される。 The control unit 60 applies the voltage Vc between the electrode 35 and the electrode 36 by the driving voltage applying unit 41 after the process of S72 (S73). Therefore, the ink extruding device 40 applies pressure to the ink 20a inside the pressure chamber 30a by the piezo element 33 when the piezo element 33 is deformed by the application of the voltage Vc. When pressure is applied to the ink 20a inside the pressure chamber 30a by the piezo element 33, one ink droplet 20b of the ink 20a inside the pressure chamber 30a charged in S71 is ejected from the nozzle 31a.
　なお、インク押出装置４０がインク２０ａに加える圧力は、インク押出装置４０および飛翔補助装置５０のうちインク押出装置４０のみでインク滴２０ｂをノズル３１ａから吐出することができる圧力である。すなわち、電圧Ｖｃは、インク押出装置４０および飛翔補助装置５０のうちインク押出装置４０のみでインク滴２０ｂをノズル３１ａから吐出することができる電圧である。一方、インク滴２０ｂの飛翔の補助のための電荷をインク２０ａに与える電圧Ｖａと、インク滴２０ｂの飛翔の補助のための静電界を発生させる電圧Ｖｂとの組み合わせは、インク押出装置４０および飛翔補助装置５０のうち飛翔補助装置５０のみでインク滴２０ｂをノズル３１ａから吐出することができない電圧である。 The pressure that the ink extruding device 40 applies to the ink 20a is a pressure at which the ink droplet 20b can be ejected from the nozzle 31a only by the ink extruding device 40 of the ink extruding device 40 and the flight assisting device 50. That is, the voltage Vc is a voltage at which the ink droplet 20b can be ejected from the nozzle 31a only by the ink extruding device 40 of the ink extruding device 40 and the flight assisting device 50. On the other hand, the combination of the voltage Va for applying the charge for assisting the flying of the ink droplet 20b to the ink 20a and the voltage Vb for generating the electrostatic field for assisting the flying of the ink droplet 20b is the combination of the ink extruding device 40 and the flying. The voltage is such that the ink droplet 20b cannot be ejected from the nozzle 31a only by the flight assisting device 50 among the assisting devices 50.
　また、インク押出装置４０がインク２０ａに加える圧力は、飛翔補助装置５０による飛翔の補助が無い場合に後述の空気抵抗Ｒに抗って記録媒体９０に到達することができる最小のサイズ未満のインク滴２０ｂをノズル３１ａから吐出する圧力である。すなわち、電圧Ｖｃは、飛翔補助装置５０による飛翔の補助が無い場合に空気抵抗Ｒに抗って記録媒体９０に到達することができない微小なサイズのインク滴２０ｂを発生させる電圧である。 Further, the pressure applied by the ink extruding device 40 to the ink 20a is less than the minimum size that can reach the recording medium 90 against the air resistance R described later when the flight assist device 50 does not assist the flight. This is the pressure at which the droplet 20b is discharged from the nozzle 31a. That is, the voltage Vc is a voltage that generates a small ink droplet 20b that cannot reach the recording medium 90 against the air resistance R when there is no flight assistance by the flight assist device 50.
　インク押出装置４０によってノズル３１ａから吐出させられたインク滴２０ｂは、Ｓ７２において飛翔補助装置５０によって生成されている静電力によって飛翔が補助される。ここで、ノズル３１ａから吐出されて電極３１ｃおよび電極５１の間を飛翔しているインク滴２０ｂは、静電引力Ｆｑを受ける。一方、ノズル３１ａから吐出されたインク滴２０ｂは、空気抵抗Ｒを受ける。したがって、インク滴２０ｂが受ける静電引力Ｆｑおよび空気抵抗Ｒが等しくなるように電圧Ｖａ、ＶｂおよびＶｃが調整されることによって、ノズル３１ａから吐出させられたインク滴２０ｂは、速度が低下することなく、記録媒体９０まで到達することができる。ここで、静電引力Ｆｑは、インク滴２０ｂが帯電している電荷ｑと、電極３１ｃおよび電極５１の間の電圧Ｖｂとに基づいて、数２のように表される。また、空気抵抗Ｒは、インク滴２０ｂの周囲の空気の密度σと、抵抗比例係数Ｃと、インク滴２０ｂの前方投影面積Ｓと、インク滴２０ｂの速度ｖとに基づいて、数３のように表される。なお、インク押出装置４０によってノズル３１ａから吐出させられたインク滴２０ｂの初速度は、電極３５および電極３６の間に印加される電圧Ｖｃの大きさによって定まる。
Figure JPOXMLDOC01-appb-M000002
Figure JPOXMLDOC01-appb-M000003
 The ink droplet 20b ejected from the nozzle 31a by the ink extruding device 40 is assisted by the electrostatic force generated by the flight assist device 50 in S72. Here, the ink droplet 20b ejected from the nozzle 31a and flying between the electrode 31c and the electrode 51 receives an electrostatic attractive force Fq. On the other hand, the ink droplet 20b ejected from the nozzle 31a receives the air resistance R. Therefore, by adjusting the voltages Va, Vb, and Vc so that the electrostatic attractive force Fq and the air resistance R received by the ink droplet 20b are equal, the speed of the ink droplet 20b ejected from the nozzle 31a decreases. The recording medium 90 can be reached. Here, the electrostatic attractive force Fq is expressed by Equation 2 based on the charge q charged in the ink droplet 20b and the voltage Vb between the electrode 31c and the electrode 51. Further, the air resistance R is expressed by the following equation 3 based on the density σ of the air around the ink droplet 20b, the resistance proportional coefficient C, the forward projection area S of the ink droplet 20b, and the velocity v of the ink droplet 20b. It is expressed in The initial velocity of the ink droplet 20b ejected from the nozzle 31a by the ink extruding device 40 is determined by the magnitude of the voltage Vc applied between the electrode 35 and the electrode 36.
Figure JPOXMLDOC01-appb-M000002
Figure JPOXMLDOC01-appb-M000003
　制御部６０は、Ｓ７３の処理の後、Ｓ７３の処理を実行してから所定の時間が経過したと判断するまで、Ｓ７３の処理を実行してから所定の時間が経過したか否かを判断する（Ｓ７４）。この所定の時間は、ノズル３１ａから吐出させられたインク滴２０ｂが記録媒体９０まで到達するまでの時間であり、インク滴２０ｂの飛翔の速度と、ノズル３１ａおよび記録媒体９０の間の距離とに基づいて取得することができる。 After the process of S73, the control unit 60 determines whether or not the predetermined time has elapsed since the execution of the process of S73 until it is determined that the predetermined time has elapsed since the execution of the process of S73. (S74). This predetermined time is a time until the ink droplet 20b ejected from the nozzle 31a reaches the recording medium 90, and the flying speed of the ink droplet 20b and the distance between the nozzle 31a and the recording medium 90 are as follows. Can be obtained on the basis.
　制御部６０は、Ｓ７３の処理を実行してから所定の時間が経過したとＳ７４において判断すると、静電界用電圧印加部５３による電圧Ｖｂの印加を終了して（Ｓ７５）、図５に示す動作を終了する。 When the control unit 60 determines in S74 that the predetermined time has elapsed since the execution of the process of S73, the application of the voltage Vb by the electrostatic field voltage application unit 53 is terminated (S75), and the operation shown in FIG. Exit.
　なお、制御部６０は、図５に示す動作において、静電界用電圧印加部５３によって電極３１ｃおよび電極５１の間に電圧Ｖｂを印加することを開始した（Ｓ７２）後、駆動用電圧印加部４１によって電極３５および電極３６の間に電圧Ｖｃを印加する（Ｓ７３）ようになっているが、インク滴２０ｂの飛翔中に静電界を発生させれば良いので、駆動用電圧印加部４１によって電極３５および電極３６の間に電圧Ｖｃを印加した後、静電界用電圧印加部５３によって電極３１ｃおよび電極５１の間に電圧Ｖｂを印加することを開始するようになっていても良い。 In the operation shown in FIG. 5, the control unit 60 starts applying the voltage Vb between the electrode 31c and the electrode 51 by the electrostatic field voltage application unit 53 (S72), and then the drive voltage application unit 41. Thus, the voltage Vc is applied between the electrode 35 and the electrode 36 (S73), but an electrostatic field may be generated during the flight of the ink droplet 20b. In addition, after the voltage Vc is applied between the electrodes 36, the application of the voltage Vb between the electrodes 31c and 51 by the electrostatic field voltage applying unit 53 may be started.
　また、制御部６０は、図５に示す動作によってノズル３１ａから１粒のインク滴２０ｂを記録媒体９０に到達させることができるが、同様にして複数粒のインク滴２０ｂをノズル３１ａから連続して記録媒体９０に到達させることができる。制御部６０は、複数粒のインク滴２０ｂをノズル３１ａから連続して記録媒体９０に到達させる場合、帯電用電圧印加部５２によって電極３１ｃおよび電極３４の間に印加する電圧Ｖａと、駆動用電圧印加部４１によって電極３５および電極３６の間に印加する電圧Ｖｃとを同一周期のパルス電圧とすることができる。ここで、制御部６０は、パルス電圧である電圧Ｖａのパルス幅を、時間Ｔａとする。また、制御部６０は、パルス電圧である電圧Ｖｃの周期を、パルス電圧である電圧Ｖａの周期より時間Ｔａ遅らせる。また、制御部６０は、少なくとも、電極３１ｃおよび電極５１の間にインク滴２０ｂが飛翔している間、静電界用電圧印加部５３によって電極３１ｃおよび電極５１の間に電圧Ｖｂを印加する。 Further, the control unit 60 can cause one ink droplet 20b to reach the recording medium 90 from the nozzle 31a by the operation shown in FIG. 5, but similarly, a plurality of ink droplets 20b are continuously provided from the nozzle 31a. The recording medium 90 can be reached. When the controller 60 causes the plurality of ink droplets 20b to continuously reach the recording medium 90 from the nozzle 31a, the voltage Va applied between the electrode 31c and the electrode 34 by the charging voltage application unit 52 and the driving voltage The voltage Vc applied between the electrode 35 and the electrode 36 by the applying unit 41 can be a pulse voltage having the same cycle. Here, the control unit 60 sets the pulse width of the voltage Va, which is a pulse voltage, as the time Ta. Further, the control unit 60 delays the cycle of the voltage Vc, which is a pulse voltage, by a time Ta from the cycle of the voltage Va, which is a pulse voltage. Further, the control unit 60 applies the voltage Vb between the electrode 31 c and the electrode 51 by the electrostatic field voltage application unit 53 at least while the ink droplet 20 b is flying between the electrode 31 c and the electrode 51.
　以上に説明したように、インク吐出システム２０は、インク押出装置４０および飛翔補助装置５０のうちインク押出装置４０のみでインク滴２０ｂをノズル３１ａから吐出することができるので、インク滴２０ｂの吐出のために飛翔補助装置５０によって高圧の静電界を発生させる必要がない。したがって、インク吐出システム２０は、記録ヘッド３０におけるノズル３１ａ間の必要な絶縁耐圧を確保しても記録ヘッド３０に従来より高密度でノズル３１ａを実装することができ、その結果、印刷速度を従来より速くすることができる。このため、インク吐出システム２０は、例えば、大きな面積の画像の印刷に適している。 As described above, the ink ejection system 20 can eject the ink droplet 20b from the nozzle 31a only by the ink extrusion device 40 of the ink extrusion device 40 and the flight assisting device 50. Therefore, it is not necessary to generate a high-voltage electrostatic field by the flight assist device 50. Therefore, the ink ejection system 20 can mount the nozzles 31a on the recording head 30 at a higher density than the conventional one even if the necessary dielectric strength between the nozzles 31a in the recording head 30 is ensured. Can be faster. For this reason, the ink ejection system 20 is suitable for printing an image having a large area, for example.
　また、インク吐出システム２０は、飛翔補助装置５０による飛翔の補助が無い場合に空気抵抗Ｒに抗って記録媒体９０に到達することができない、例えば１ｐｌ（ピコリットル）以下の微小なサイズのインク滴２０ｂを記録媒体９０に到達させるので、極めて細い線を記録媒体９０上に印刷することができる。例えば、インク吐出システム２０は、ナノ銀などの金属ナノ粒子を分散させたインク２０ａの微小なインク滴２０ｂを記録媒体９０に到達させることによって、５μｍなど、１０μｍ以下の極めて細い線で記録媒体９０上にプリント配線を印刷することができる。 In addition, the ink ejection system 20 cannot reach the recording medium 90 against the air resistance R when there is no flight assistance by the flight assist device 50, for example, ink of a minute size of 1 pl (picoliter) or less. Since the droplet 20b reaches the recording medium 90, a very thin line can be printed on the recording medium 90. For example, the ink ejection system 20 causes the recording medium 90 to have a very thin line of 10 μm or less, such as 5 μm, by reaching the recording medium 90 with fine ink droplets 20b of the ink 20a in which metal nanoparticles such as nano silver are dispersed. Printed wiring can be printed on top.
　また、インク吐出システム２０は、電極３１ｃおよび電極５１の間の距離を延長することによって、インク滴２０ｂの飛翔距離を容易に延長することができる。例えば、インク吐出システム２０は、ノズル３１ａと、記録媒体９０との間の距離が５ｍｍであっても０．０１ｐｌのインク滴２０ｂを記録媒体９０に到達させることができる。 Further, the ink ejection system 20 can easily extend the flight distance of the ink droplet 20b by extending the distance between the electrode 31c and the electrode 51. For example, the ink ejection system 20 can cause the ink droplet 20b of 0.01 pl to reach the recording medium 90 even if the distance between the nozzle 31a and the recording medium 90 is 5 mm.
　また、インク吐出システム２０は、同極性電極である電極３１ｃが、記録ヘッド３０のうちノズル３１ａが形成されている部材であるノズルプレート３１の一部を構成しているので、記録ヘッド３０と、同極性電極とが別々に設けられている構成と比較して、簡単な構成で実現されることができる。 Further, in the ink ejection system 20, since the electrode 31c that is the same polarity electrode constitutes a part of the nozzle plate 31 that is a member in which the nozzle 31a is formed in the recording head 30, the recording head 30; Compared to a configuration in which the same polarity electrodes are provided separately, the configuration can be realized with a simple configuration.
　（第２の実施の形態）
　まず、本実施の形態に係るインクジェットプリンターの構成について説明する。 (Second Embodiment)
First, the configuration of the ink jet printer according to the present embodiment will be described.
　なお、本実施の形態に係るインクジェットプリンターの構成のうち第１の実施の形態に係るインクジェットプリンター１０（図１参照。）の構成と同様の構成については、インクジェットプリンター１０の構成と同一の符号を付して詳細な説明を省略する。 In addition, about the structure similar to the structure of the inkjet printer 10 (refer FIG. 1) which concerns on 1st Embodiment among the structures of the inkjet printer which concerns on this Embodiment, the code | symbol same as the structure of the inkjet printer 10 is shown. Detailed description will be omitted.
　図６は、本発明の第２の実施の形態に係るインクジェットプリンターに備えられているインク吐出システム１２０の正面から見た模式図である。 FIG. 6 is a schematic view seen from the front of the ink ejection system 120 provided in the ink jet printer according to the second embodiment of the present invention.
　本実施の形態に係るインクジェットプリンターの構成は、インクジェットプリンター１０（図１参照。）がインク吐出システム２０（図３参照。）に代えて図６に示すインク吐出システム１２０を備えた構成と同様である。 The configuration of the inkjet printer according to the present embodiment is the same as the configuration in which the inkjet printer 10 (see FIG. 1) includes the ink ejection system 120 shown in FIG. 6 instead of the ink ejection system 20 (see FIG. 3). is there.
　インク吐出システム１２０の構成は、記録ヘッド１３０および飛翔補助装置１５０を記録ヘッド３０（図３参照。）および飛翔補助装置５０（図３参照。）に代えてインク吐出システム２０が備えた構成と同様である。 The configuration of the ink ejection system 120 is the same as the configuration provided in the ink ejection system 20 instead of the recording head 30 (see FIG. 3) and the flying assistance device 50 (see FIG. 3). It is.
　記録ヘッド１３０の構成は、全体が電極であるノズルプレート１３１と、ノズルプレート１３１に電気的に接続されている電極１３２とを、ノズルプレート３１（図３参照。）および電極３４（図３参照。）に代えて記録ヘッド３０が備えた構成と同様である。 The configuration of the recording head 130 includes a nozzle plate 131 that is an electrode as a whole and an electrode 132 that is electrically connected to the nozzle plate 131, a nozzle plate 31 (see FIG. 3), and an electrode 34 (see FIG. 3). The recording head 30 has the same configuration as that shown in FIG.
　飛翔補助装置１５０は、上述のノズルプレート１３１および電極１３２と、ノズルプレート１３１に対して記録媒体９０側に配置されている電極５１と、ノズルプレート１３１および電極５１の間に電圧を印加する電圧印加部１５１とを備えている。 The flying assist device 150 applies voltage between the nozzle plate 131 and the electrode 132 described above, the electrode 51 disposed on the recording medium 90 side with respect to the nozzle plate 131, and the nozzle plate 131 and the electrode 51. Part 151.
　ここで、ノズルプレート１３１は、ノズル３１ａから吐出させられるインク滴２０ｂと同種の極性に帯電させられる電極であり、本発明の同極性電極を構成している。すなわち、ノズルプレート１３１は、電極５１とともに本発明の一対の静電界用電極を構成している。また、ノズルプレート１３１は、記録ヘッド１３０に収納されているインク２０ａを帯電させる電極であり、本発明の帯電用電極を構成している。 Here, the nozzle plate 131 is an electrode that is charged to the same kind of polarity as the ink droplet 20b ejected from the nozzle 31a, and constitutes the same polarity electrode of the present invention. That is, the nozzle plate 131 constitutes a pair of electrostatic field electrodes of the present invention together with the electrode 51. The nozzle plate 131 is an electrode for charging the ink 20a stored in the recording head 130, and constitutes the charging electrode of the present invention.
　また、電極１３２は、記録ヘッド１３０に収納されているインク２０ａを帯電させる電極であり、本発明の帯電用電極を構成している。 The electrode 132 is an electrode for charging the ink 20a accommodated in the recording head 130, and constitutes the charging electrode of the present invention.
　次に、インク吐出システム１２０の動作について説明する。 Next, the operation of the ink ejection system 120 will be described.
　図７は、ノズル３１ａから１粒のインク滴２０ｂを記録媒体９０に到達させる場合の制御部６０の動作のフローチャートである。 FIG. 7 is a flowchart of the operation of the control unit 60 when one ink droplet 20b reaches the recording medium 90 from the nozzle 31a.
　図７に示すように、制御部６０は、電圧印加部１５１によってノズルプレート１３１に電圧Ｖｂを印加することを開始する（Ｓ１７１）。したがって、飛翔補助装置１５０は、圧力室３０ａの内部のインク２０ａを、ノズルプレート１３１および電極１３２からの電荷の注入、または、ノズルプレート１３１および電極１３２によって生じた電界による分極によって、例えば正に帯電させる。また、飛翔補助装置１５０は、ノズルプレート１３１および電極５１の間に静電界を生成する。 As shown in FIG. 7, the control unit 60 starts applying the voltage Vb to the nozzle plate 131 by the voltage application unit 151 (S171). Therefore, the flying assist device 150 charges the ink 20a inside the pressure chamber 30a, for example, positively by injection of charges from the nozzle plate 131 and the electrode 132 or polarization due to an electric field generated by the nozzle plate 131 and the electrode 132. Let Further, the flying assist device 150 generates an electrostatic field between the nozzle plate 131 and the electrode 51.
　制御部６０は、Ｓ１７１の処理の後、Ｓ１７１の処理を実行してから時間Ｔａが経過したと判断するまで、Ｓ１７１の処理を実行してから時間Ｔａが経過したか否かを判断する（Ｓ１７２）。この時間Ｔａは、第１の実施の形態に係る時間Ｔａと同様である。例えば、時間Ｔａが０．１ｍｓである場合、インク２０ａは、比抵抗ρが約１０９Ωｃｍ以下、好ましくは１０８Ωｃｍ以下のインクであれば良い。 After the process of S171, the control unit 60 determines whether or not the time Ta has elapsed since the execution of the process of S171 until it is determined that the time Ta has elapsed since the execution of the process of S171 (S172). ). This time Ta is the same as the time Ta according to the first embodiment. For example, when the time Ta is 0.1 ms, the ink 20a may be an ink having a specific resistance ρ of about 10 9 Ωcm or less, preferably 10 8 Ωcm or less.
　制御部６０は、Ｓ１７１の処理を実行してから時間Ｔａが経過したとＳ１７２において判断すると、駆動用電圧印加部４１によって電極３５および電極３６の間に電圧Ｖｃを印加する（Ｓ１７３）。したがって、インク押出装置４０は、電圧Ｖｃの印加によってピエゾ素子３３が変形することによって、圧力室３０ａの内部のインク２０ａにピエゾ素子３３によって圧力を加える。圧力室３０ａの内部のインク２０ａにピエゾ素子３３によって圧力が加えられると、Ｓ１７１において帯電させられた圧力室３０ａの内部のインク２０ａのうち１粒のインク滴２０ｂがノズル３１ａから吐出される。 When the control unit 60 determines in S172 that the time Ta has elapsed since the execution of the processing of S171, the driving voltage application unit 41 applies the voltage Vc between the electrode 35 and the electrode 36 (S173). Therefore, the ink extruding device 40 applies pressure to the ink 20a inside the pressure chamber 30a by the piezo element 33 when the piezo element 33 is deformed by the application of the voltage Vc. When pressure is applied to the ink 20a inside the pressure chamber 30a by the piezo element 33, one ink droplet 20b out of the ink 20a inside the pressure chamber 30a charged in S171 is ejected from the nozzle 31a.
　なお、インク押出装置４０がインク２０ａに加える圧力は、インク押出装置４０および飛翔補助装置１５０のうちインク押出装置４０のみでインク滴２０ｂをノズル３１ａから吐出することができる圧力である。すなわち、電圧Ｖｃは、インク押出装置４０および飛翔補助装置１５０のうちインク押出装置４０のみでインク滴２０ｂをノズル３１ａから吐出することができる電圧である。一方、インク２０ａの飛翔の補助のための電圧Ｖｂは、インク押出装置４０および飛翔補助装置１５０のうち飛翔補助装置１５０のみでインク滴２０ｂをノズル３１ａから吐出することができない電圧である。 The pressure that the ink extruding device 40 applies to the ink 20a is a pressure at which the ink droplet 20b can be ejected from the nozzle 31a only by the ink extruding device 40 of the ink extruding device 40 and the flight assisting device 150. That is, the voltage Vc is a voltage at which the ink droplet 20b can be ejected from the nozzle 31a only by the ink extrusion device 40 of the ink extrusion device 40 and the flight assist device 150. On the other hand, the voltage Vb for assisting the flying of the ink 20a is a voltage at which the ink droplet 20b cannot be ejected from the nozzle 31a only by the flying assist device 150 of the ink extruding device 40 and the flying assist device 150.
　また、インク押出装置４０がインク２０ａに加える圧力は、飛翔補助装置１５０による飛翔の補助が無い場合に空気抵抗Ｒに抗って記録媒体９０に到達することができる最小のサイズ未満のインク滴２０ｂをノズル３１ａから吐出する圧力である。すなわち、電圧Ｖｃは、飛翔補助装置１５０による飛翔の補助が無い場合に空気抵抗Ｒに抗って記録媒体９０に到達することができない微小なサイズのインク滴２０ｂを発生させる電圧である。 Further, the pressure applied to the ink 20a by the ink extruding device 40 is less than the minimum size of the ink droplet 20b that can reach the recording medium 90 against the air resistance R when there is no flying assistance by the flying assistance device 150. Is the pressure at which the gas is discharged from the nozzle 31a. That is, the voltage Vc is a voltage that generates a small ink droplet 20b that cannot reach the recording medium 90 against the air resistance R when there is no flight assistance by the flight assist device 150.
　インク押出装置４０によってノズル３１ａから吐出させられたインク滴２０ｂは、Ｓ１７１において飛翔補助装置１５０によって生成されている静電力によって飛翔が補助される。 The ink droplet 20b ejected from the nozzle 31a by the ink extruding device 40 is assisted by the electrostatic force generated by the flight assist device 150 in S171.
　制御部６０は、Ｓ１７３の処理の後、Ｓ１７３の処理を実行してから所定の時間が経過したと判断するまで、Ｓ１７３の処理を実行してから所定の時間が経過したか否かを判断する（Ｓ１７４）。この所定の時間は、ノズル３１ａから吐出させられたインク滴２０ｂが記録媒体９０まで到達するまでの時間であり、インク滴２０ｂの飛翔の速度と、ノズル３１ａおよび記録媒体９０の間の距離とに基づいて取得することができる。 After the process of S173, the control unit 60 determines whether or not the predetermined time has elapsed since the execution of the process of S173 until it is determined that the predetermined time has elapsed since the execution of the process of S173. (S174). This predetermined time is a time until the ink droplet 20b ejected from the nozzle 31a reaches the recording medium 90, and the flying speed of the ink droplet 20b and the distance between the nozzle 31a and the recording medium 90 are as follows. Can be obtained on the basis.
　制御部６０は、Ｓ１７３の処理を実行してから所定の時間が経過したとＳ１７４において判断すると、電圧印加部１５１による電圧Ｖｂの印加を終了して（Ｓ１７５）、図７に示す動作を終了する。 When determining in S174 that the predetermined time has elapsed since the execution of the process of S173, the control unit 60 ends the application of the voltage Vb by the voltage application unit 151 (S175) and ends the operation shown in FIG. .
　なお、制御部６０は、図７に示す動作によってノズル３１ａから１粒のインク滴２０ｂを記録媒体９０に到達させることができるが、同様にして複数粒のインク滴２０ｂをノズル３１ａから連続して記録媒体９０に到達させることができる。制御部６０は、複数粒のインク滴２０ｂをノズル３１ａから連続して記録媒体９０に到達させる場合、駆動用電圧印加部４１によって電極３５および電極３６の間に印加する電圧Ｖｃをパルス電圧とすることができる。ここで、制御部６０は、パルス電圧である電圧Ｖｃの周期を時間Ｔａ以上とする。また、制御部６０は、少なくとも、ノズルプレート１３１および電極５１の間にインク滴２０ｂが飛翔している間、電圧印加部１５１によってノズルプレート１３１および電極５１の間に電圧Ｖｂを印加する。 Note that the control unit 60 can cause one ink droplet 20b to reach the recording medium 90 from the nozzle 31a by the operation shown in FIG. 7, but similarly, a plurality of ink droplets 20b are continuously delivered from the nozzle 31a. The recording medium 90 can be reached. When the controller 60 causes the plurality of ink droplets 20b to reach the recording medium 90 continuously from the nozzle 31a, the voltage Vc applied between the electrode 35 and the electrode 36 by the driving voltage applying unit 41 is set as a pulse voltage. be able to. Here, the control unit 60 sets the cycle of the voltage Vc, which is a pulse voltage, to a time Ta or more. Further, the control unit 60 applies the voltage Vb between the nozzle plate 131 and the electrode 51 by the voltage application unit 151 at least while the ink droplet 20 b is flying between the nozzle plate 131 and the electrode 51.
　以上に説明したように、インク吐出システム１２０は、インク押出装置４０および飛翔補助装置１５０のうちインク押出装置４０のみでインク滴２０ｂをノズル３１ａから吐出することができるので、インク滴２０ｂの吐出のために飛翔補助装置１５０によって高圧の静電界を発生させる必要がない。したがって、インク吐出システム１２０は、記録ヘッド１３０におけるノズル３１ａ間の必要な絶縁耐圧を確保しても記録ヘッド１３０に従来より高密度でノズル３１ａを実装することができ、その結果、印刷速度を従来より速くすることができる。 As described above, the ink ejection system 120 can eject the ink droplet 20b from the nozzle 31a only by the ink extrusion device 40 of the ink extrusion device 40 and the flight assist device 150. Therefore, it is not necessary to generate a high-voltage electrostatic field by the flying assist device 150. Therefore, the ink ejection system 120 can mount the nozzles 31a on the recording head 130 at a higher density than the conventional one even if the necessary withstand voltage between the nozzles 31a in the recording head 130 is ensured. Can be faster.
　また、インク吐出システム１２０は、飛翔補助装置１５０による飛翔の補助が無い場合に空気抵抗Ｒに抗って記録媒体９０に到達することができない微小なサイズのインク滴２０ｂを記録媒体９０に到達させるので、極めて細い線を記録媒体９０上に印刷することができる。 In addition, the ink ejection system 120 causes the ink droplet 20b of a minute size that cannot reach the recording medium 90 against the air resistance R to reach the recording medium 90 when there is no flying assistance by the flying assist device 150. Therefore, extremely thin lines can be printed on the recording medium 90.
　また、インク吐出システム１２０は、ノズルプレート１３１および電極５１の間の距離を延長することによって、インク滴２０ｂの飛翔距離を容易に延長することができる。 Also, the ink ejection system 120 can easily extend the flight distance of the ink droplet 20b by extending the distance between the nozzle plate 131 and the electrode 51.
　また、インク吐出システム１２０は、同極性電極であるノズルプレート１３１が、記録ヘッド１３０のうちノズル３１ａが形成されている部材を構成しているので、記録ヘッド１３０と、同極性電極とが別々に設けられている構成と比較して、簡単な構成で実現されることができる。 Further, in the ink ejection system 120, the nozzle plate 131 that is the same polarity electrode constitutes a member in which the nozzle 31a is formed in the recording head 130, so that the recording head 130 and the same polarity electrode are separately provided. Compared to the provided configuration, it can be realized with a simple configuration.
　インク吐出システム１２０は、帯電用電極が同極性電極の一部、すなわち、ノズルプレート１３１を備えているので、図３に示すように帯電用電極、すなわち電極３４と、同極性電極、すなわち電極３１ｃとが別々に設けられている構成と比較して、簡単な構成で実現されることができる。 In the ink ejection system 120, since the charging electrode includes a part of the same polarity electrode, that is, the nozzle plate 131, as shown in FIG. 3, the charging electrode, that is, the electrode 34, and the same polarity electrode, that is, the electrode 31c. Can be realized with a simple configuration as compared with a configuration in which and are separately provided.
　なお、インク吐出システム１２０は、例えばインク２０ａが導電性を有する場合など、電極１３２を備えていなくてもインク２０ａの帯電に支障がない場合には、図８に示すように、電極１３２を備えていなくても良い。 Note that the ink ejection system 120 includes the electrode 132 as shown in FIG. 8 when there is no problem in charging the ink 20a even when the ink 20a is not provided, such as when the ink 20a has conductivity. It does not have to be.
　インク吐出システム１２０は、図８に示す構成である場合、帯電用電極が同極性電極、すなわち、ノズルプレート１３１であるので、図６に示すように帯電用電極の一部、すなわち、電極１３２が同極性電極、すなわち、ノズルプレート１３１と別である構成と比較して、簡単な構成で実現されることができる。 When the ink discharge system 120 has the configuration shown in FIG. 8, the charging electrode is the same polarity electrode, that is, the nozzle plate 131. Therefore, as shown in FIG. Compared to the same polarity electrode, that is, a configuration different from the nozzle plate 131, it can be realized with a simple configuration.
　また、インク吐出システム１２０は、図８に示す構成である場合、電極３４（図３参照。）または電極１３２（図６参照。）のように圧力室３０ａの内部に設けられている電極を備えていないので、既存の記録ヘッドがそのまま記録ヘッド１３０として採用されることができる。したがって、インク吐出システム１２０は、図８に示す構成である場合、低コストで実現されることができる。 In the case of the configuration shown in FIG. 8, the ink ejection system 120 includes an electrode provided inside the pressure chamber 30a like the electrode 34 (see FIG. 3) or the electrode 132 (see FIG. 6). Therefore, an existing recording head can be used as the recording head 130 as it is. Therefore, the ink ejection system 120 can be realized at a low cost when it has the configuration shown in FIG.
　また、インク吐出システム１２０は、インク２０ａの帯電に支障がない場合には、図９に示すように、図８に示す構成において更にノズルプレート１３１をノズルプレート１３３に代えても良い。 Further, when there is no problem in charging the ink 20a, the ink ejection system 120 may further replace the nozzle plate 131 with the nozzle plate 133 in the configuration shown in FIG. 8, as shown in FIG.
　ここで、ノズルプレート１３３は、壁部３２に取り付けられているプレート本体１３３ａと、プレート本体１３３ａのうち壁部３２側とは反対側の表面に設けられている電極１３３ｂとを備えている。 Here, the nozzle plate 133 includes a plate main body 133a attached to the wall portion 32, and an electrode 133b provided on the surface of the plate main body 133a opposite to the wall portion 32 side.
　プレート本体１３３ａは、例えば絶縁性のプラスチックなどの絶縁体によって構成されている。 The plate body 133a is made of an insulator such as insulating plastic.
　電極１３３ｂは、ノズル３１ａから吐出させられるインク滴２０ｂと同種の極性に帯電させられる電極であり、本発明の同極性電極を構成している。すなわち、電極１３３ｂは、電極５１とともに本発明の一対の静電界用電極を構成している。また、電極１３３ｂは、記録ヘッド１３０に収納されているインク２０ａを帯電させる電極であり、本発明の帯電用電極を構成している。 The electrode 133b is an electrode that is charged to the same kind of polarity as the ink droplet 20b ejected from the nozzle 31a, and constitutes the same polarity electrode of the present invention. That is, the electrode 133b constitutes a pair of electrostatic field electrodes of the present invention together with the electrode 51. The electrode 133b is an electrode for charging the ink 20a stored in the recording head 130, and constitutes the charging electrode of the present invention.
　インク吐出システム１２０は、図９に示す構成である場合、帯電用電極が同極性電極、すなわち、電極１３３ｂであるので、図６に示すように帯電用電極の一部、すなわち、電極１３２が同極性電極、すなわち、ノズルプレート１３１と別である構成と比較して、簡単な構成で実現されることができる。 In the case of the ink ejection system 120 having the configuration shown in FIG. 9, since the charging electrode is the same polarity electrode, that is, the electrode 133b, a part of the charging electrode, that is, the electrode 132 is the same as shown in FIG. Compared with a configuration that is different from the polarity electrode, that is, the nozzle plate 131, it can be realized with a simple configuration.
　また、インク吐出システム１２０は、図９に示す構成である場合、電極３４（図３参照。）または電極１３２（図６参照。）のように圧力室３０ａの内部に設けられている電極を備えていないので、既存の記録ヘッドがそのまま、または、ノズルプレートに導電化処理が施されるだけで記録ヘッド１３０として採用されることができる。したがって、インク吐出システム１２０は、図９に示す構成である場合、低コストで実現されることができる。 Further, in the case of the configuration shown in FIG. 9, the ink ejection system 120 includes an electrode provided inside the pressure chamber 30a like the electrode 34 (see FIG. 3) or the electrode 132 (see FIG. 6). Therefore, the existing recording head can be used as the recording head 130 as it is or simply by subjecting the nozzle plate to a conductive treatment. Therefore, the ink ejection system 120 can be realized at a low cost when it has the configuration shown in FIG.
　（第３の実施の形態）
　まず、本実施の形態に係るインクジェットプリンターの構成について説明する。 (Third embodiment)
First, the configuration of the ink jet printer according to the present embodiment will be described.
　なお、本実施の形態に係るインクジェットプリンターの構成のうち第２の実施の形態に係るインクジェットプリンターの構成と同様の構成については、第２の実施の形態に係るインクジェットプリンターの構成と同一の符号を付して詳細な説明を省略する。 In addition, about the structure similar to the structure of the inkjet printer which concerns on 2nd Embodiment among the structures of the inkjet printer which concerns on this Embodiment, the code | symbol same as the structure of the inkjet printer which concerns on 2nd Embodiment is shown. Detailed description will be omitted.
　図１０は、本発明の第３の実施の形態に係るインクジェットプリンターに備えられているインク吐出システム４２０の正面から見た模式図である。 FIG. 10 is a schematic view seen from the front of the ink ejection system 420 provided in the ink jet printer according to the third embodiment of the present invention.
　本実施の形態に係るインクジェットプリンターの構成は、第２の実施の形態に係るインクジェットプリンターがインク吐出システム１２０（図６参照。）に代えて図１０に示すインク吐出システム４２０を備えた構成と同様である。 The configuration of the ink jet printer according to the present embodiment is the same as the configuration in which the ink jet printer according to the second embodiment includes the ink discharge system 420 shown in FIG. 10 instead of the ink discharge system 120 (see FIG. 6). It is.
　インク吐出システム４２０の構成は、飛翔補助装置４５０を飛翔補助装置１５０（図６参照。）に代えてインク吐出システム１２０が備えた構成と同様である。 The configuration of the ink ejection system 420 is the same as the configuration provided in the ink ejection system 120 in place of the flight assist device 450 in place of the flight assist device 150 (see FIG. 6).
　飛翔補助装置４５０の構成は、ノズルプレート１３１および電極５１の間に電圧を印加する電圧印加部４５１を電圧印加部１５１（図６参照。）に代えて飛翔補助装置１５０が備えた構成と同様である。 The configuration of the flight assist device 450 is the same as the configuration of the flight assist device 150 provided in place of the voltage application unit 151 (see FIG. 6) instead of the voltage application unit 451 that applies a voltage between the nozzle plate 131 and the electrode 51. is there.
　次に、インク吐出システム４２０の動作について説明する。 Next, the operation of the ink ejection system 420 will be described.
　図１１は、ノズル３１ａから１粒のインク滴２０ｂを記録媒体９０に到達させる場合の制御部６０の動作のフローチャートである。 FIG. 11 is a flowchart of the operation of the control unit 60 when one ink droplet 20b reaches the recording medium 90 from the nozzle 31a.
　図１１に示すように、制御部６０は、電圧印加部４５１によってノズルプレート１３１に電圧Ｖｂを印加することを開始するとともに、駆動用電圧印加部４１によって電極３５および電極３６の間に電圧Ｖｃを印加する（Ｓ４７１）。 As shown in FIG. 11, the control unit 60 starts applying the voltage Vb to the nozzle plate 131 by the voltage application unit 451, and applies the voltage Vc between the electrode 35 and the electrode 36 by the driving voltage application unit 41. Apply (S471).
　したがって、飛翔補助装置４５０は、圧力室３０ａの内部のインク２０ａを、ノズルプレート１３１および電極１３２からの電荷の注入、または、ノズルプレート１３１および電極１３２によって生じた電界による分極によって、例えば正に帯電させる。また、飛翔補助装置４５０は、ノズルプレート１３１および電極５１の間に静電界を生成する。 Therefore, the flying assist device 450 charges the ink 20a inside the pressure chamber 30a, for example, positively by injection of charges from the nozzle plate 131 and the electrode 132 or polarization due to an electric field generated by the nozzle plate 131 and the electrode 132. Let Further, the flying assist device 450 generates an electrostatic field between the nozzle plate 131 and the electrode 51.
　また、インク押出装置４０は、電圧Ｖｃの印加によってピエゾ素子３３が変形することによって、圧力室３０ａの内部のインク２０ａにピエゾ素子３３によって圧力を加える。
圧力室３０ａの内部のインク２０ａにピエゾ素子３３によって圧力が加えられると、飛翔補助装置４５０によって帯電させられた圧力室３０ａの内部のインク２０ａのうち１粒のインク滴２０ｂがノズル３１ａから吐出される。 Further, the ink extruding device 40 applies pressure to the ink 20a inside the pressure chamber 30a by the piezo element 33 when the piezo element 33 is deformed by the application of the voltage Vc.
When pressure is applied to the ink 20a inside the pressure chamber 30a by the piezo element 33, one ink droplet 20b out of the ink 20a inside the pressure chamber 30a charged by the flying assist device 450 is ejected from the nozzle 31a. The
　なお、インク押出装置４０がインク２０ａに加える圧力は、インク押出装置４０および飛翔補助装置４５０のうちインク押出装置４０のみでインク滴２０ｂをノズル３１ａから吐出することができる圧力である。すなわち、電圧Ｖｃは、インク押出装置４０および飛翔補助装置４５０のうちインク押出装置４０のみでインク滴２０ｂをノズル３１ａから吐出することができる電圧である。一方、インク２０ａの飛翔の補助のための電圧Ｖｂは、インク押出装置４０および飛翔補助装置４５０のうち飛翔補助装置４５０のみでインク滴２０ｂをノズル３１ａから吐出することができない電圧である。 The pressure that the ink extruding device 40 applies to the ink 20a is a pressure at which the ink droplet 20b can be ejected from the nozzle 31a only by the ink extruding device 40 of the ink extruding device 40 and the flight assisting device 450. That is, the voltage Vc is a voltage at which the ink droplet 20b can be ejected from the nozzle 31a only by the ink extruding device 40 of the ink extruding device 40 and the flight assisting device 450. On the other hand, the voltage Vb for assisting the flying of the ink 20a is a voltage at which the ink droplet 20b cannot be ejected from the nozzle 31a only by the flying assisting device 450 of the ink extruding device 40 and the flying assisting device 450.
　また、インク押出装置４０がインク２０ａに加える圧力は、飛翔補助装置４５０による飛翔の補助が無い場合に空気抵抗Ｒに抗って記録媒体９０に到達することができる最小のサイズ未満のインク滴２０ｂをノズル３１ａから吐出する圧力である。すなわち、電圧Ｖｃは、飛翔補助装置４５０による飛翔の補助が無い場合に空気抵抗Ｒに抗って記録媒体９０に到達することができない微小なサイズのインク滴２０ｂを発生させる電圧である。 Further, the pressure applied by the ink extruding device 40 to the ink 20a is less than the minimum size of the ink droplet 20b that can reach the recording medium 90 against the air resistance R when the flying assist device 450 does not assist the flight. Is the pressure at which the gas is discharged from the nozzle 31a. That is, the voltage Vc is a voltage that generates a small ink droplet 20b that cannot reach the recording medium 90 against the air resistance R when there is no flight assistance by the flight assist device 450.
　インク押出装置４０によってノズル３１ａから吐出させられたインク滴２０ｂは、Ｓ４７１において飛翔補助装置４５０によって生成されている静電力によって飛翔が補助される。 The ink droplet 20b ejected from the nozzle 31a by the ink extruding device 40 is assisted by the electrostatic force generated by the flight assist device 450 in S471.
　なお、Ｓ４７１の処理を実行してから、１粒のインク滴２０ｂがノズル３１ａから吐出されるまでの時間は、第２の実施の形態に係る時間Ｔａと同様の時間以上の時間である。 Note that the time from the execution of the process of S471 to the ejection of one ink droplet 20b from the nozzle 31a is equal to or longer than the time Ta according to the second embodiment.
　次いで、制御部６０は、Ｓ４７１の処理の後、Ｓ４７１の処理を実行してから時間Ｔｂが経過したと判断するまで、Ｓ４７１の処理を実行してから時間Ｔｂが経過したか否かを判断する（Ｓ４７２）。この時間Ｔｂは、パルス電圧である電圧Ｖｃが印加されている時間と、ノズル３１ａから吐出させられたインク滴２０ｂが記録媒体９０まで到達するまでの時間との合計時間と同一の時間であるか、この合計時間より若干長い時間であって、予め設定されている時間である。なお、ノズル３１ａから吐出させられたインク滴２０ｂが記録媒体９０まで到達するまでの時間は、インク滴２０ｂの飛翔の速度と、ノズル３１ａおよび記録媒体９０の間の距離とに基づいて取得することができる。 Next, after the process of S471, the control unit 60 determines whether or not the time Tb has elapsed since the execution of the process of S471 until it is determined that the time Tb has elapsed since the execution of the process of S471. (S472). Is this time Tb the same as the total time of the time when the voltage Vc, which is a pulse voltage, is applied and the time until the ink droplet 20b ejected from the nozzle 31a reaches the recording medium 90? The time is slightly longer than the total time and is a preset time. The time until the ink droplet 20b ejected from the nozzle 31a reaches the recording medium 90 is acquired based on the flying speed of the ink droplet 20b and the distance between the nozzle 31a and the recording medium 90. Can do.
　制御部６０は、Ｓ４７１の処理を実行してから時間Ｔｂが経過したとＳ４７２において判断すると、電圧印加部４５１による電圧Ｖｂの印加を終了して（Ｓ４７３）、図１１に示す動作を終了する。 When the control unit 60 determines in S472 that the time Tb has elapsed since the execution of the processing of S471, the application of the voltage Vb by the voltage application unit 451 is terminated (S473), and the operation illustrated in FIG.
　なお、制御部６０は、図１１に示す動作によってノズル３１ａから１粒のインク滴２０ｂを記録媒体９０に到達させることができるが、同様にして複数粒のインク滴２０ｂをノズル３１ａから連続して記録媒体９０に到達させることができる。すなわち、制御部６０は、ノズル３１ａからのインク滴２０ｂの吐出の度に、パルス電圧である電圧Ｖｂおよび電圧Ｖｃを発生させる。 The control unit 60 can cause one ink droplet 20b to reach the recording medium 90 from the nozzle 31a by the operation shown in FIG. 11, but similarly, a plurality of ink droplets 20b are continuously provided from the nozzle 31a. The recording medium 90 can be reached. That is, the control unit 60 generates the voltage Vb and the voltage Vc, which are pulse voltages, every time the ink droplet 20b is ejected from the nozzle 31a.
　以上に説明したように、インク吐出システム４２０は、一対の静電界用電極、すなわち、電極５１およびノズルプレート１３１の間に印加される電圧Ｖｂが、インク押出装置４０にインク滴２０ｂをノズル３１ａから押し出させるパルス電圧である電圧Ｖｃより幅が広いパルス電圧であるので、電極５１およびノズルプレート１３１の間に高い電圧Ｖｂを常に印加する構成と比較して、安全性を向上することができる。 As described above, the ink ejection system 420 is configured such that the voltage Vb applied between the pair of electrostatic field electrodes, that is, the electrode 51 and the nozzle plate 131, causes the ink ejection device 40 to eject the ink droplet 20b from the nozzle 31a. Since the pulse voltage is wider than the voltage Vc that is the pulse voltage to be pushed out, safety can be improved as compared with a configuration in which a high voltage Vb is always applied between the electrode 51 and the nozzle plate 131.
　なお、インク吐出システム４２０は、記録ヘッド１３０の構成が図８または図９に示す構成であっても良い。 In the ink ejection system 420, the configuration of the recording head 130 may be the configuration shown in FIG. 8 or FIG.
　（第４の実施の形態）
　まず、本実施の形態に係るインクジェットプリンターの構成について説明する。 (Fourth embodiment)
First, the configuration of the ink jet printer according to the present embodiment will be described.
　なお、本実施の形態に係るインクジェットプリンターの構成のうち第１の実施の形態に係るインクジェットプリンター１０（図１参照。）の構成と同様の構成については、インクジェットプリンター１０の構成と同一の符号を付して詳細な説明を省略する。 In addition, about the structure similar to the structure of the inkjet printer 10 (refer FIG. 1) which concerns on 1st Embodiment among the structures of the inkjet printer which concerns on this Embodiment, the code | symbol same as the structure of the inkjet printer 10 is shown. Detailed description will be omitted.
　図１２は、本発明の第４の実施の形態に係るインクジェットプリンターに備えられているインク吐出システム２２０の正面から見た模式図である。 FIG. 12 is a schematic view seen from the front of the ink ejection system 220 provided in the ink jet printer according to the fourth embodiment of the present invention.
　本実施の形態に係るインクジェットプリンターの構成は、インクジェットプリンター１０（図１参照。）がインク吐出システム２０（図３参照。）に代えて図１２に示すインク吐出システム２２０を備えた構成と同様である。 The configuration of the ink jet printer according to the present embodiment is the same as the configuration in which the ink jet printer 10 (see FIG. 1) includes the ink discharge system 220 shown in FIG. 12 instead of the ink discharge system 20 (see FIG. 3). is there.
　インク吐出システム２２０の構成は、記録ヘッド２３０および飛翔補助装置２５０を記録ヘッド３０（図３参照。）および飛翔補助装置５０（図３参照。）に代えてインク吐出システム２０が備えた構成と同様である。 The configuration of the ink ejection system 220 is the same as the configuration provided in the ink ejection system 20 instead of the recording head 30 (see FIG. 3) and the flying assistance device 50 (see FIG. 3). It is.
　記録ヘッド２３０の構成は、全体が電極であるノズルプレート２３１と、ノズルプレート２３１に電気的に接続されている電極２３２とを、ノズルプレート３１（図３参照。）および電極３４（図３参照。）に代えて記録ヘッド３０が備えた構成と同様である。 The configuration of the recording head 230 includes a nozzle plate 231 that is an electrode as a whole and an electrode 232 that is electrically connected to the nozzle plate 231, a nozzle plate 31 (see FIG. 3), and an electrode 34 (see FIG. 3). The recording head 30 has the same configuration as that shown in FIG.
　飛翔補助装置２５０は、上述のノズルプレート２３１および電極２３２と、記録媒体９０に対して記録ヘッド２３０側に配置されている電極２５１と、電極２５１に対して記録媒体９０側に配置されている電極５１と、電極２５１およびノズルプレート２３１の間に電圧を印加する帯電用電圧印加部５２と、電極２５１および電極５１の間に電圧を印加する静電界用電圧印加部５３とを備えている。 The flight assist device 250 includes the nozzle plate 231 and the electrode 232 described above, the electrode 251 disposed on the recording head 230 side with respect to the recording medium 90, and the electrode disposed on the recording medium 90 side with respect to the electrode 251. 51, a charging voltage applying unit 52 that applies a voltage between the electrode 251 and the nozzle plate 231, and an electrostatic field voltage applying unit 53 that applies a voltage between the electrode 251 and the electrode 51.
　電極２５１は、ノズル３１ａから吐出させられるインク滴２０ｂが通過するための孔２５１ａが形成されている。 The electrode 251 has a hole 251a through which the ink droplet 20b ejected from the nozzle 31a passes.
　ここで、ノズルプレート２３１および電極２３２は、記録ヘッド２３０に収納されているインク２０ａを帯電させる電極であり、本発明の帯電用電極を構成している。 Here, the nozzle plate 231 and the electrode 232 are electrodes for charging the ink 20a accommodated in the recording head 230, and constitute the charging electrode of the present invention.
　また、電極２５１は、ノズル３１ａから吐出させられるインク滴２０ｂと同種の極性に帯電させられる電極であり、本発明の同極性電極を構成している。すなわち、電極２５１は、電極５１とともに本発明の一対の静電界用電極を構成している。 The electrode 251 is an electrode that is charged to the same kind of polarity as the ink droplet 20b ejected from the nozzle 31a, and constitutes the same polarity electrode of the present invention. That is, the electrode 251 constitutes a pair of electrostatic field electrodes of the present invention together with the electrode 51.
　インク吐出システム２２０の動作は、第１の実施の形態に係るインク吐出システム２０の動作と同様であるので、説明を省略する。 Since the operation of the ink ejection system 220 is the same as the operation of the ink ejection system 20 according to the first embodiment, the description thereof is omitted.
　以上に説明したように、インク吐出システム２２０は、インク押出装置４０および飛翔補助装置２５０のうちインク押出装置４０のみでインク滴２０ｂをノズル３１ａから吐出することができるので、インク滴２０ｂの吐出のために飛翔補助装置２５０によって高圧の静電界を発生させる必要がない。したがって、インク吐出システム２２０は、記録ヘッド２３０におけるノズル３１ａ間の必要な絶縁耐圧を確保しても記録ヘッド２３０に従来より高密度でノズル３１ａを実装することができ、その結果、印刷速度を従来より速くすることができる。 As described above, the ink ejection system 220 can eject the ink droplet 20b from the nozzle 31a only by the ink extrusion device 40 of the ink extrusion device 40 and the flight assist device 250. Therefore, it is not necessary to generate a high-voltage electrostatic field by the flying assist device 250. Therefore, the ink ejection system 220 can mount the nozzles 31a on the recording head 230 at a higher density than the conventional one even if the necessary dielectric strength between the nozzles 31a in the recording head 230 is ensured. Can be faster.
　また、インク吐出システム２２０は、飛翔補助装置２５０による飛翔の補助が無い場合に空気抵抗Ｒに抗って記録媒体９０に到達することができない微小なサイズのインク滴２０ｂを記録媒体９０に到達させるので、極めて細い線を記録媒体９０上に印刷することができる。 In addition, the ink ejection system 220 causes the ink droplet 20b of a minute size that cannot reach the recording medium 90 against the air resistance R to reach the recording medium 90 when the flying assist device 250 does not assist the flight. Therefore, extremely thin lines can be printed on the recording medium 90.
　また、インク吐出システム２２０は、電極２５１および電極５１の間の距離を延長することによって、インク滴２０ｂの飛翔距離を容易に延長することができる。 Further, the ink ejection system 220 can easily extend the flight distance of the ink droplet 20b by extending the distance between the electrode 251 and the electrode 51.
　なお、インク吐出システム２２０は、例えばインク２０ａが導電性を有する場合など、電極２３２を備えていなくてもインク２０ａの帯電に支障がない場合には、図１３に示すように、電極２３２を備えていなくても良い。 Note that the ink ejection system 220 includes the electrode 232 as illustrated in FIG. 13 when there is no problem in charging the ink 20a even when the ink 20a is not provided, such as when the ink 20a has conductivity. It does not have to be.
　インク吐出システム２２０は、図１３に示す構成である場合、電極３４（図３参照。）または電極２３２（図１２参照。）のように圧力室３０ａの内部に設けられている電極を備えていないので、既存の記録ヘッドがそのまま記録ヘッド２３０として採用されることができる。したがって、インク吐出システム２２０は、図１３に示す構成である場合、低コストで実現されることができる。 In the case of the configuration shown in FIG. 13, the ink ejection system 220 does not include an electrode provided inside the pressure chamber 30a like the electrode 34 (see FIG. 3) or the electrode 232 (see FIG. 12). Therefore, an existing recording head can be employed as the recording head 230 as it is. Therefore, the ink ejection system 220 can be realized at a low cost when it has the configuration shown in FIG.
　また、インク吐出システム２２０は、インク２０ａの帯電に支障がない場合には、図１４に示すように、図１３に示す構成において更にノズルプレート２３１をノズルプレート２３３に代えても良い。 Further, the ink ejection system 220 may further replace the nozzle plate 231 with the nozzle plate 233 in the configuration shown in FIG. 13 as shown in FIG. 14 when there is no problem in charging the ink 20a.
　ここで、ノズルプレート２３３は、壁部３２に取り付けられているプレート本体２３３ａと、プレート本体２３３ａのうち壁部３２側とは反対側の表面に設けられている電極２３３ｂとを備えている。 Here, the nozzle plate 233 includes a plate body 233a attached to the wall portion 32, and an electrode 233b provided on the surface of the plate body 233a opposite to the wall portion 32 side.
　プレート本体２３３ａは、例えば絶縁性のプラスチックなどの絶縁体によって構成されている。 The plate body 233a is made of an insulator such as insulating plastic.
　電極２３３ｂは、記録ヘッド２３０に収納されているインク２０ａを帯電させる電極であり、本発明の帯電用電極を構成している。 The electrode 233b is an electrode for charging the ink 20a stored in the recording head 230, and constitutes the charging electrode of the present invention.
　インク吐出システム２２０は、図１４に示す構成である場合、電極３４（図３参照。）または電極２３２（図１２参照。）のように圧力室３０ａの内部に設けられている電極を備えていないので、既存の記録ヘッドがそのまま、または、ノズルプレートに導電化処理が施されるだけで記録ヘッド２３０として採用されることができる。したがって、インク吐出システム２２０は、図１４に示す構成である場合、低コストで実現されることができる。 In the case of the configuration shown in FIG. 14, the ink ejection system 220 does not include an electrode provided inside the pressure chamber 30a like the electrode 34 (see FIG. 3) or the electrode 232 (see FIG. 12). Therefore, the existing recording head can be employed as the recording head 230 as it is or simply by conducting the conductive treatment on the nozzle plate. Therefore, the ink ejection system 220 can be realized at a low cost when it has the configuration shown in FIG.
（第５の実施の形態）　まず、本実施の形態に係るインクジェットプリンターの構成について説明する。 (5th Embodiment) First, the structure of the inkjet printer which concerns on this Embodiment is demonstrated.
　なお、本実施の形態に係るインクジェットプリンターの構成のうち第１の実施の形態に係るインクジェットプリンター１０（図１参照。）の構成と同様の構成については、インクジェットプリンター１０の構成と同一の符号を付して詳細な説明を省略する。 In addition, about the structure similar to the structure of the inkjet printer 10 (refer FIG. 1) which concerns on 1st Embodiment among the structures of the inkjet printer which concerns on this Embodiment, the code | symbol same as the structure of the inkjet printer 10 is shown. Detailed description will be omitted.
　図１５は、本発明の第５の実施の形態に係るインクジェットプリンターに備えられているインク吐出システム３２０の正面から見た模式図である。 FIG. 15 is a schematic view seen from the front of the ink ejection system 320 provided in the ink jet printer according to the fifth embodiment of the present invention.
　本実施の形態に係るインクジェットプリンターの構成は、インクジェットプリンター１０（図１参照。）がインク吐出システム２０（図３参照。）に代えて図１５に示すインク吐出システム３２０を備えた構成と同様である。 The configuration of the ink jet printer according to the present embodiment is the same as the configuration in which the ink jet printer 10 (see FIG. 1) includes the ink discharge system 320 shown in FIG. 15 instead of the ink discharge system 20 (see FIG. 3). is there.
　インク吐出システム３２０の構成は、記録ヘッド３３０、インク押出装置３４０および飛翔補助装置３５０を記録ヘッド３０（図３参照。）、インク押出装置４０（図３参照。）および飛翔補助装置５０（図３参照。）に代えてインク吐出システム２０が備えた構成と同様である。 The configuration of the ink ejection system 320 includes a recording head 330, an ink extruding device 340, and a flight assisting device 350. Instead of the above, the configuration of the ink ejection system 20 is the same.
　インク吐出システム３２０のインク２０ａは、導電性を有するインクである。 The ink 20a of the ink ejection system 320 is a conductive ink.
　記録ヘッド３３０の構成は、ノズルプレート３１に取り付けられているシェアモードのピエゾ素子３３１と、ピエゾ素子３３１に取り付けられている壁部３３２と、ピエゾ素子３３１に取り付けられている電極３３３および電極３３４とを、壁部３２（図３参照。）、ピエゾ素子３３（図３参照。）、電極３４（図３参照。）、電極３５（図３参照。）および電極３６（図３参照。）に代えて記録ヘッド３０が備えた構成と同様である。 The recording head 330 includes a shear mode piezo element 331 attached to the nozzle plate 31, a wall 332 attached to the piezo element 331, an electrode 333 and an electrode 334 attached to the piezo element 331. Are replaced with a wall 32 (see FIG. 3), a piezo element 33 (see FIG. 3), an electrode 34 (see FIG. 3), an electrode 35 (see FIG. 3) and an electrode 36 (see FIG. 3). The configuration of the recording head 30 is the same.
　壁部３３２は、例えば絶縁性のプラスチックなどの絶縁体によって構成されている。 The wall portion 332 is made of an insulator such as insulating plastic.
　インク押出装置３４０は、上述のピエゾ素子３３１、電極３３３および電極３３４と、電極３３３および電極３３４の間に電圧を印加する電圧印加部３４１とを備えている。 The ink extruding device 340 includes the above-described piezo element 331, electrode 333, and electrode 334, and a voltage applying unit 341 that applies a voltage between the electrode 333 and the electrode 334.
　電極３３３および電極３３４は、インク押出装置３４０の駆動用の電極である。特に、電極３３３は、圧力室３０ａの内部に設けられており、本発明の圧力室内駆動用電極を構成している。 The electrode 333 and the electrode 334 are electrodes for driving the ink extruding device 340. In particular, the electrode 333 is provided inside the pressure chamber 30a and constitutes the pressure chamber driving electrode of the present invention.
　飛翔補助装置３５０は、ノズルプレート３１の電極３１ｃと、電極５１と、電極３３３および電極３３４と、電圧印加部３４１と、電圧を印加する電圧印加部３５１とを備えている。 The flight assist device 350 includes an electrode 31c of the nozzle plate 31, an electrode 51, an electrode 333 and an electrode 334, a voltage application unit 341, and a voltage application unit 351 that applies a voltage.
　電圧印加部３５１は、電極３１ｃおよび電極３３４と、電極５１との間に電圧を印加するようになっている。 The voltage application unit 351 applies a voltage between the electrode 31 c and the electrode 334 and the electrode 51.
　ここで、電極３３３は、記録ヘッド３３０に収納されているインク２０ａを帯電させる電極であり、本発明の帯電用電極を構成している。 Here, the electrode 333 is an electrode for charging the ink 20a stored in the recording head 330, and constitutes the charging electrode of the present invention.
　次に、インク吐出システム３２０の動作について説明する。 Next, the operation of the ink ejection system 320 will be described.
　インク吐出システム３２０の動作のうち以下に説明する動作以外の動作については、第１の実施の形態に係るインク吐出システム２０の動作と同様であるので、説明を省略する。 Of the operations of the ink ejection system 320, operations other than those described below are the same as the operations of the ink ejection system 20 according to the first embodiment, and thus description thereof is omitted.
　制御部６０は、電圧印加部３４１によって電極３３３および電極３３４の間に電圧Ｖｃを印加する。したがって、飛翔補助装置３５０は、圧力室３０ａの内部のインク２０ａを、電極３３３からの電荷の注入によって、例えば正に帯電させる。また、インク押出装置３４０は、電圧Ｖｃの印加によってピエゾ素子３３１が変形することによって、圧力室３０ａの内部のインク２０ａにピエゾ素子３３１によって圧力を加える。圧力室３０ａの内部のインク２０ａにピエゾ素子３３１によって圧力が加えられると、帯電させられた圧力室３０ａの内部のインク２０ａのうち１粒のインク滴２０ｂがノズル３１ａから吐出される。 The control unit 60 applies the voltage Vc between the electrode 333 and the electrode 334 by the voltage application unit 341. Accordingly, the flying assist device 350 charges the ink 20a inside the pressure chamber 30a positively, for example, by injecting charges from the electrode 333. Further, the ink extruding device 340 applies pressure to the ink 20a inside the pressure chamber 30a by the piezo element 331 when the piezo element 331 is deformed by the application of the voltage Vc. When pressure is applied to the ink 20a inside the pressure chamber 30a by the piezo element 331, one ink droplet 20b out of the charged ink 20a inside the pressure chamber 30a is ejected from the nozzle 31a.
　以上に説明したように、インク吐出システム３２０は、インク押出装置３４０および飛翔補助装置３５０のうちインク押出装置３４０のみでインク滴２０ｂをノズル３１ａから吐出することができるので、インク滴２０ｂの吐出のために飛翔補助装置３５０によって高圧の静電界を発生させる必要がない。したがって、インク吐出システム３２０は、記録ヘッド３３０におけるノズル３１ａ間の必要な絶縁耐圧を確保しても記録ヘッド３３０に従来より高密度でノズル３１ａを実装することができ、その結果、印刷速度を従来より速くすることができる。 As described above, the ink ejection system 320 can eject the ink droplet 20b from the nozzle 31a only by the ink extrusion device 340 out of the ink extrusion device 340 and the flight assisting device 350. Therefore, it is not necessary to generate a high-voltage electrostatic field by the flying assist device 350. Therefore, the ink ejection system 320 can mount the nozzles 31a on the recording head 330 at a higher density than the conventional one even if the necessary withstand voltage between the nozzles 31a in the recording head 330 is ensured. Can be faster.
　また、インク吐出システム３２０は、飛翔補助装置３５０による飛翔の補助が無い場合に空気抵抗Ｒに抗って記録媒体９０に到達することができない微小なサイズのインク滴２０ｂを記録媒体９０に到達させるので、極めて細い線を記録媒体９０上に印刷することができる。 In addition, the ink ejection system 320 causes the ink droplets 20b of minute size that cannot reach the recording medium 90 against the air resistance R to reach the recording medium 90 when there is no flying assistance by the flying assistance device 350. Therefore, extremely thin lines can be printed on the recording medium 90.
　また、インク吐出システム３２０は、電極３１ｃおよび電極５１の間の距離を延長することによって、インク滴２０ｂの飛翔距離を容易に延長することができる。 Also, the ink ejection system 320 can easily extend the flight distance of the ink droplet 20b by extending the distance between the electrode 31c and the electrode 51.
　また、インク吐出システム３２０は、同極性電極である電極３１ｃが、記録ヘッド３３０のうちノズル３１ａが形成されている部材であるノズルプレート３１の一部を構成しているので、記録ヘッド３３０と、同極性電極とが別々に設けられている構成と比較して、簡単な構成で実現されることができる。 Further, in the ink ejection system 320, since the electrode 31c that is the same polarity electrode constitutes a part of the nozzle plate 31 that is a member in which the nozzle 31a is formed in the recording head 330, the recording head 330, Compared to a configuration in which the same polarity electrodes are provided separately, the configuration can be realized with a simple configuration.
　また、インク吐出システム３２０は、帯電用電極が圧力室内駆動用電極、すなわち、電極３３３であるので、帯電用電極と、圧力室内駆動用電極とが別々に設けられている構成と比較して、簡単な構成で実現されることができる。 Further, in the ink ejection system 320, since the charging electrode is the pressure chamber driving electrode, that is, the electrode 333, compared with the configuration in which the charging electrode and the pressure chamber driving electrode are separately provided, It can be realized with a simple configuration.
　また、インク吐出システム３２０は、圧力室内駆動用電極を備えている既存の記録ヘッドがそのまま、または、ノズルプレートに導電化処理が施されるだけで記録ヘッド３３０として採用されることができる。したがって、インク吐出システム３２０は、低コストで実現されることができる。 Also, the ink ejection system 320 can be used as the recording head 330 as it is, with an existing recording head provided with an electrode for driving in the pressure chamber as it is or simply by conducting a conductive treatment on the nozzle plate. Therefore, the ink ejection system 320 can be realized at a low cost.
　また、上述した各実施の形態に係るインクジェットプリンターにおける飛翔補助装置は、インクを正に帯電させるようになっているが、負に帯電させるようになっていても良い。なお、上述した各実施の形態に係るインクジェットプリンターにおける飛翔補助装置は、インクを負に帯電させるようになっている場合、静電界の向きも上述した各実施の形態における向きと逆になる。 Further, although the flight assist device in the ink jet printer according to each of the above-described embodiments charges the ink positively, it may be negatively charged. In the flight assist device in the ink jet printer according to each of the above-described embodiments, when the ink is negatively charged, the direction of the electrostatic field is also opposite to the direction in each of the above-described embodiments.
　また、上述した各実施の形態に係るインクジェットプリンターにおけるインク押出装置は、シェアモードのピエゾ素子によってインクに圧力を加えることによってインク滴をノズルから押し出す装置である。しかしながら、上述した各実施の形態に係るインクジェットプリンターにおけるインク押出装置は、シェアモード以外のモードのピエゾ素子によってインクに圧力を加えることによってインク滴をノズルから押し出す装置であっても良い。例えば、上述した各実施の形態に係るインクジェットプリンターにおけるインク押出装置のピエゾ素子は、撓みモードのピエゾ素子、縦モードのピエゾ素子、横モードのピエゾ素子などであっても良い。 Also, the ink extrusion device in the ink jet printer according to each of the above-described embodiments is a device that pushes ink droplets out of the nozzles by applying pressure to the ink with a shear mode piezo element. However, the ink extrusion device in the ink jet printer according to each of the above-described embodiments may be a device that pushes ink droplets out of the nozzles by applying pressure to the ink with a piezo element in a mode other than the share mode. For example, the piezo element of the ink extrusion apparatus in the ink jet printer according to each of the above-described embodiments may be a flexure mode piezo element, a longitudinal mode piezo element, a transverse mode piezo element, or the like.
　また、上述した各実施の形態に係るインクジェットプリンターにおけるインク押出装置は、ピエゾ素子によってインクに圧力を加えることによってインク滴をノズルから押し出す装置である。しかしながら、上述した各実施の形態に係るインクジェットプリンターにおけるインク押出装置は、ピエゾ素子以外の構成によってインクに圧力を加えることによってインク滴をノズルから押し出す装置であっても良い。例えば、上述した各実施の形態に係るインクジェットプリンターにおけるインク押出装置は、インクの加熱によってインク内に発生させた気泡によってインクに圧力を加えることによってインク滴をノズルから押し出すサーマルジェット（バブルジェット（登録商標））方式の装置であっても良い。 Also, the ink extrusion device in the ink jet printer according to each of the above-described embodiments is a device that pushes ink droplets out of the nozzles by applying pressure to the ink with a piezo element. However, the ink extrusion device in the ink jet printer according to each of the above-described embodiments may be a device that pushes ink droplets out of the nozzles by applying pressure to the ink with a configuration other than the piezo element. For example, the ink extruding device in the ink jet printer according to each of the above-described embodiments includes a thermal jet (bubble jet (registered) that pushes ink droplets out of the nozzles by applying pressure to the ink by bubbles generated in the ink by heating the ink. Trademark)) type apparatus.
　また、上述した各実施の形態におけるインクジェットプリンターは、図１に示すように、主走査方向に移動しない記録媒体９０に対してキャリッジ１１ｂによって主走査方向に記録ヘッドを移動させることによって記録ヘッドによる主走査方向の印刷を実行させ、副走査方向に移動しない記録ヘッドに対して副走査方向に記録媒体９０を搬送することによって記録媒体９０に対する記録ヘッドの副走査方向における位置を主走査方向の印刷の終了の度に変更する方式のプリンターである。しかしながら、インクジェットプリンターは、上述した各実施の形態における方式以外の方式のプリンターであっても良い。例えば、インクジェットプリンターは、テーブルに載置されて移動しない記録媒体９０に対してキャリッジ１１ｂによって主走査方向に記録ヘッドを移動させることによって記録ヘッドによる主走査方向の印刷を実行させ、記録媒体９０が載置されているテーブルに対して副走査方向に本体１１を移動させることによって記録媒体９０に対する記録ヘッドの副走査方向における位置を主走査方向の印刷の終了の度に変更する方式のインクジェットプリンターであっても良い。 Further, as shown in FIG. 1, the ink jet printer in each of the above-described embodiments moves the recording head in the main scanning direction by the carriage 11b with respect to the recording medium 90 that does not move in the main scanning direction. By performing printing in the scanning direction and transporting the recording medium 90 in the sub-scanning direction with respect to the recording head that does not move in the sub-scanning direction, the position of the recording head in the sub-scanning direction relative to the recording medium 90 is set in the printing in the main scanning direction. This is a printer that changes every time it is finished. However, the ink jet printer may be a printer of a method other than the methods in the above-described embodiments. For example, the inkjet printer causes the recording head 90 to perform printing in the main scanning direction by moving the recording head in the main scanning direction by the carriage 11b with respect to the recording medium 90 that is placed on the table and does not move. An ink jet printer that changes the position of the recording head in the sub-scanning direction relative to the recording medium 90 by moving the main body 11 in the sub-scanning direction with respect to the mounted table every time printing in the main scanning direction is completed. There may be.
　２０　インク吐出システム
　２０ａ　インク
　２０ｂ　インク滴（インクの粒）
　３０　記録ヘッド
　３０ａ　圧力室
　３１ａ　ノズル
　３１ｃ　電極（静電界用電極、同極性電極）
　３４　電極（帯電用電極）
　４０　インク押出装置
　５０　飛翔補助装置
　５１　電極（静電界用電極、異極性電極）
　６０　制御部
　９０　記録媒体
　１２０　インク吐出システム
　１３０　記録ヘッド
　１３１　ノズルプレート（帯電用電極、静電界用電極、同極性電極）
　１３２　電極（帯電用電極）
　１３３ｂ　電極（帯電用電極、静電界用電極、同極性電極）
　１５０　飛翔補助装置
　２２０　インク吐出システム
　２３０　記録ヘッド
　２３１　ノズルプレート（帯電用電極）
　２３２　電極（帯電用電極）
　２３３ｂ　電極（帯電用電極）
　２５０　飛翔補助装置
　２５１　電極（静電界用電極、同極性電極）
　３２０　インク吐出システム
　３３０　記録ヘッド
　３３３　電極（帯電用電極、圧力室内駆動用電極）
　３４０　インク押出装置
　３５０　飛翔補助装置
　４２０　インク吐出システム
　４５０　飛翔補助装置 20 Ink Discharge System 20a Ink 20b Ink Drop (Ink Particles)
30 recording head 30a pressure chamber 31a nozzle 31c electrode (electrostatic field electrode, same polarity electrode)
34 Electrodes (charging electrodes)
40 Ink Extruder 50 Flying Auxiliary Device 51 Electrode (Electrostatic Electrode, Electropolar Electrode)
60 Control unit 90 Recording medium 120 Ink ejection system 130 Recording head 131 Nozzle plate (charging electrode, electrostatic field electrode, same polarity electrode)
132 electrode (charging electrode)
133b Electrode (charging electrode, electrostatic field electrode, same polarity electrode)
150 flying assist device 220 ink discharge system 230 recording head 231 nozzle plate (charging electrode)
232 electrode (charging electrode)
233b Electrode (charging electrode)
250 Flying assistance device 251 Electrode (Electrostatic field electrode, same polarity electrode)
320 Ink ejection system 330 Recording head 333 Electrode (charging electrode, pressure chamber driving electrode)
340 Ink Extrusion Device 350 Flying Aid Device 420 Ink Ejection System 450 Flying Aid Device

Claims (7)

  1. 　記録媒体に向けてインクの粒を吐出するためのノズルを複数備えている記録ヘッドと、前記記録ヘッドに収納されている前記インクに圧力を加えることによって前記インクの前記粒を前記ノズルから押し出すインク押出装置と、前記粒の飛翔を静電力によって補助する飛翔補助装置と、前記インク押出装置および前記飛翔補助装置の動作を制御する制御部とを備えており、
    　前記制御部は、前記記録ヘッドに収納されている前記インクを前記飛翔補助装置に帯電させ、前記飛翔補助装置によって帯電させられた前記インクの前記粒を前記インク押出装置によって前記ノズルから吐出させ、前記インク押出装置によって前記ノズルから吐出させられた前記粒の飛翔を前記静電力によって前記飛翔補助装置に補助させ、
    　前記インク押出装置が前記インクに加える前記圧力は、前記インク押出装置および前記飛翔補助装置のうち前記インク押出装置のみで前記粒を前記ノズルから吐出することができる圧力であって、前記飛翔補助装置による飛翔の補助が無い場合に空気抵抗に抗って前記記録媒体に到達することができる最小のサイズ未満の前記粒を前記ノズルから吐出する圧力であることを特徴とするインク吐出システム。     A recording head having a plurality of nozzles for ejecting ink particles toward the recording medium, and ink that pushes out the ink particles from the nozzles by applying pressure to the ink stored in the recording head An extrusion device, a flight assist device that assists the flying of the particles by electrostatic force, and a control unit that controls operations of the ink extrusion device and the flight assist device,
    The control unit charges the ink stored in the recording head to the flying assist device, causes the ink ejection device to discharge the particles of the ink charged from the nozzle by the ink pushing device, Causing the flying assist device to assist the flying of the particles ejected from the nozzle by the ink extruding device with the electrostatic force;
    The pressure applied to the ink by the ink extruding device is a pressure at which the particles can be ejected from the nozzle only by the ink extruding device of the ink extruding device and the flying auxiliary device, and the flying auxiliary device An ink ejection system having a pressure for ejecting the particles having a size less than a minimum size that can reach the recording medium against air resistance in the absence of flying assistance by the nozzle.
  2. 　前記飛翔補助装置は、前記記録ヘッドに収納されている前記インクを帯電させる帯電用電極と、前記ノズルから吐出させられた前記粒に前記静電力を与える静電界を発生させる一対の静電界用電極とを備えており、
    　前記一対の静電界用電極は、前記ノズルから吐出させられる前記粒と同種の極性に帯電させられる同極性電極と、前記ノズルから吐出させられる前記粒と異種の極性に帯電させられる異極性電極とによって構成されており、
    　前記同極性電極は、前記記録媒体に対して前記記録ヘッド側に配置されており、
    　前記異極性電極は、前記同極性電極に対して前記記録媒体側に配置されていることを特徴とする請求項１に記載のインク吐出システム。     The flying assist device includes a charging electrode for charging the ink accommodated in the recording head, and a pair of electrostatic field electrodes for generating an electrostatic field for applying the electrostatic force to the particles ejected from the nozzle. And
    The pair of electrostatic field electrodes includes a same polarity electrode that is charged to the same polarity as the particles discharged from the nozzle, and a different polarity electrode that is charged to a different polarity from the particles discharged from the nozzle. Consists of
    The same polarity electrode is arranged on the recording head side with respect to the recording medium,
    The ink ejection system according to claim 1, wherein the different polarity electrode is disposed on the recording medium side with respect to the same polarity electrode.
  3. 　前記同極性電極は、前記記録ヘッドのうち前記ノズルが形成されている部材の少なくとも一部を構成していることを特徴とする請求項２に記載のインク吐出システム。 3. The ink ejection system according to claim 2, wherein the same polarity electrode constitutes at least a part of a member of the recording head where the nozzle is formed.
  4. 　前記帯電用電極は、前記同極性電極の少なくとも一部を備えていることを特徴とする請求項３に記載のインク吐出システム。 4. The ink ejection system according to claim 3, wherein the charging electrode includes at least a part of the same polarity electrode.
  5. 　前記帯電用電極は、前記同極性電極であることを特徴とする請求項４に記載のインク吐出システム。 The ink discharge system according to claim 4, wherein the charging electrode is the same polarity electrode.
  6. 　前記一対の静電界用電極の間に印加される電圧は、前記インク押出装置に前記インクの前記粒を前記ノズルから押し出させるパルス電圧より幅が広いパルス電圧であることを特徴とする請求項４または請求項５に記載のインク吐出システム。 5. The voltage applied between the pair of electrostatic field electrodes is a pulse voltage that is wider than a pulse voltage that causes the ink extruding device to extrude the particles of ink from the nozzle. Alternatively, the ink ejection system according to claim 5.
  7. 　前記記録ヘッドは、収納している前記インクに前記インク押出装置によって前記圧力が加えられる圧力室が形成されており、
    　前記インク押出装置は、前記インク押出装置自身の駆動用の電極であって前記圧力室の内部に設けられている圧力室内駆動用電極を備えており、
    　前記帯電用電極は、前記圧力室内駆動用電極の少なくとも一部を備えていることを特徴とする請求項２に記載のインク吐出システム。     The recording head is formed with a pressure chamber in which the pressure is applied to the ink stored therein by the ink pushing device,
    The ink extruding device includes an electrode for driving the ink extruding device itself and a pressure chamber driving electrode provided inside the pressure chamber,
    The ink discharge system according to claim 2, wherein the charging electrode includes at least a part of the pressure chamber driving electrode.
PCT/JP2013/080833 2012-11-17 2013-11-14 Ink discharging system WO2014077335A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3778239A1 (en) * 2019-08-16 2021-02-17 FRAUNHOFER-GESELLSCHAFT zur Förderung der angewandten Forschung e.V. Method and device for parallel extruding of pressurized medium onto a substrate

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10926536B2 (en) * 2017-08-31 2021-02-23 Suntory Holdings Limited Printing system, printing device, and method of producing printed object
JP2020026100A (en) * 2018-08-13 2020-02-20 株式会社ミマキエンジニアリング Printer

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11268277A (en) * 1998-03-20 1999-10-05 Toshiba Corp Ink-jet recording apparatus
JP2001232798A (en) * 2000-02-25 2001-08-28 Hitachi Koki Co Ltd Ink jet recorder and its recording method
JP2004066092A (en) * 2002-08-06 2004-03-04 Fuji Photo Film Co Ltd Discharge head, coating device, and coating method
JP2005136151A (en) * 2003-10-30 2005-05-26 Konica Minolta Holdings Inc Liquid discharging device
EP1797961A1 (en) * 2004-07-26 2007-06-20 Konica Minolta Holdings, Inc. Liquid discharging device
JP2007245533A (en) * 2006-03-16 2007-09-27 Seiko Epson Corp Inkjet printer
WO2008026455A1 (en) * 2006-08-31 2008-03-06 Konica Minolta Holdings, Inc. Method for manufacturing nozzle plate for liquid ejection head, nozzle plate for liquid ejection head, and liquid ejection head
JP2008080807A (en) * 2006-09-27 2008-04-10 Samsung Electro Mech Co Ltd Ink jetting device and method
JP2009090608A (en) * 2007-10-11 2009-04-30 Konica Minolta Holdings Inc Electrostatic suction type ink jet head and ink jet recorder
US20100265289A1 (en) * 2009-04-17 2010-10-21 Samsung Electronics Co., Ltd. Methods of driving an inkjet printing apparatus
JP2013056545A (en) * 2011-09-08 2013-03-28 Samsung Electronics Co Ltd Printing apparatus

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11268277A (en) * 1998-03-20 1999-10-05 Toshiba Corp Ink-jet recording apparatus
JP2001232798A (en) * 2000-02-25 2001-08-28 Hitachi Koki Co Ltd Ink jet recorder and its recording method
JP2004066092A (en) * 2002-08-06 2004-03-04 Fuji Photo Film Co Ltd Discharge head, coating device, and coating method
JP2005136151A (en) * 2003-10-30 2005-05-26 Konica Minolta Holdings Inc Liquid discharging device
EP1797961A1 (en) * 2004-07-26 2007-06-20 Konica Minolta Holdings, Inc. Liquid discharging device
JP2007245533A (en) * 2006-03-16 2007-09-27 Seiko Epson Corp Inkjet printer
WO2008026455A1 (en) * 2006-08-31 2008-03-06 Konica Minolta Holdings, Inc. Method for manufacturing nozzle plate for liquid ejection head, nozzle plate for liquid ejection head, and liquid ejection head
JP2008080807A (en) * 2006-09-27 2008-04-10 Samsung Electro Mech Co Ltd Ink jetting device and method
JP2009090608A (en) * 2007-10-11 2009-04-30 Konica Minolta Holdings Inc Electrostatic suction type ink jet head and ink jet recorder
US20100265289A1 (en) * 2009-04-17 2010-10-21 Samsung Electronics Co., Ltd. Methods of driving an inkjet printing apparatus
JP2013056545A (en) * 2011-09-08 2013-03-28 Samsung Electronics Co Ltd Printing apparatus

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3778239A1 (en) * 2019-08-16 2021-02-17 FRAUNHOFER-GESELLSCHAFT zur Förderung der angewandten Forschung e.V. Method and device for parallel extruding of pressurized medium onto a substrate

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