CN211843700U - Thermal printer - Google Patents

Abstract

The utility model relates to a thermal printer, including base, holder, printing device and pressure paper roller bearing, the printing device front side is connected with the holder through the support column, and its rear side is connected with the holder through the deformation structure, the printing device can produce when receiving the inhomogeneous pressure that comes from exerting of recording paper and use the swing of support column as the fulcrum makes this pressure tend to be even, and the deformation structure can produce plastic deformation in order to keep the position of printing device; and an elastic member that is provided between the holder and the base and that brings the printing apparatus and the platen roller into close contact with the recording paper in a state where the recording paper is held between the printing apparatus and the platen roller. The utility model discloses make the printer print in-process printing device ability atress evenly be being used in printing the printing paper to it is more clear to make to print.

Description

Thermal printer

Technical Field

The utility model relates to a printer field specifically, relates to a thermal printer.

Background

Thermal printers are commonly used printing devices, and are mature due to technical upgrading for years. However, the requirements on printing quality are higher and higher, and thus higher requirements on innovation are provided. To provide better print quality, the applicant, the diss global application, discloses a patent "photo printer", with the patent numbers: 201710598703.2, the publication date is 2018, 1 month and 30 days, and the contents are as follows: a photo printer for printing an image or a text by applying heat of a predetermined temperature to a paper sheet having a thermal-sensitive color expressed thereon, comprising: a substrate accommodating the paper; a pickup roller protruding from a bottom surface of the base plate to feed the accommodated paper forward; a paper pressing roller for discharging the paper supplied by the paper pickup roller forward; a head portion formed on an upper portion of the platen roller and configured to apply heat to the paper; a swing bracket having a mounting portion formed at a front side thereof to which the head portion is coupled, and a coupling portion formed at a rear side thereof to be rotatably coupled to the base plate so that the head portion swings; and a pressing member for pressing the head portion downward to be in close contact with the paper fed between the head portion and the platen roller.

In the above patent, since the rotation shaft of the swing frame is formed at the rear side of the rotation shaft of the platen roller, when the paper enters, the head portion is easily rotated according to the pressure applied to the head portion, and the compression of the platen roller is minimized, thereby enabling the paper and the platen roller to be in line contact to the maximum extent and improving the printing quality.

Above-mentioned patent is beating printing paper and is getting into when pressing paper roller bearing and head, because of the uneven and swing of atress about poor or the paper left and right sides thickness of both sides spring tension causes the head, nevertheless can not keep the position unchanged after the swing, and the different heats of printing in-process cause about supporting force different again totally to make the head make the printing line skew in its position of dynamic adjustment all the time, concrete as follows analysis: when the head (thermal head) heats the paper (when the black with a deeper depth is continuously printed), as shown in fig. 1, the temperature of the corresponding part of the printing paper rises and becomes hot, and when the printing paper is conveyed forwards, the frictional resistance f1 becomes large, and the force of the paper-pressing roller to transfer the printing paper becomes large, the reaction force f2 is increased correspondingly, and because the periphery of the paper pressing roller is colloid, when the reaction force f2 is increased, which causes the deformation of the circular cross-section of the gel (as shown in fig. 1), the head of the above-mentioned patent descends under the force F of the pressing means, so that the heating unit on the head is deviated from its original position, the supporting force F1 is moved to the position F2, and only when the force generated by the deformation amount of the gel is equal to the supporting force multiplied by the friction coefficient, the colloid deformation can be stopped, the head position can be stabilized, and finally the printing point deviates from the correct printing line position to influence the printing quality.

SUMMERY OF THE UTILITY MODEL

In order to solve the above technical problem, the present invention provides a thermal printer, including a base, a holder, a printing device, and a platen roller, wherein the holder is provided on the base, the printing device is disposed along a width direction of a recording sheet, the platen roller is disposed opposite to the printing device, and rotates to send out the recording sheet in a state where the recording sheet is held between the platen roller and the printing device; the front side of the printing device is connected with the retainer through a support column, the rear side of the printing device is connected with the retainer through a deformation structure, when the printing device is subjected to uneven pressure applied by recording paper, the printing device can swing with the support column as a fulcrum to enable the pressure to tend to be even, and the deformation structure can generate plastic deformation to keep the position of the printing device; and an elastic member that is provided between the holder and the base and that brings the printing apparatus and the platen roller into close contact with the recording paper in a state where the recording paper is held between the printing apparatus and the platen roller.

Preferably, the printing apparatus includes a swing frame and a thermal head, the swing frame is connected to the holder through a support column at a front side thereof and connected to the holder through a deformation structure at a rear side thereof, the swing frame is capable of swinging about the support column as a fulcrum when the thermal head receives an uneven pressure applied from the recording paper to make the pressure tend to be uniform, and the deformation structure is capable of plastically deforming to hold a position of the swing frame.

Preferably, the strut section of the support post between the retainer and the swing frame is adjustably positioned therebetween to vary the pretension of the swing frame and the retainer.

Preferably, the support column is adjustably mounted on the holder by a threaded structure.

Preferably, the support post is located between the retainer and the swing frame, and is a part of one of the two and protrudes toward the other to form a swing fulcrum of the swing frame.

Preferably, the deformation structure comprises a deformation part and a connecting part for connecting the retainer and the swing frame, and when the swing frame swings, the deformation part can generate plastic deformation to keep the swing position of the swing frame.

Preferably, the deformation structure is arranged on the retainer and comprises a connecting part and a deformation part, the connecting part is formed by hollowing out the retainer, and the rear side of the swing frame is fixed on the connecting part.

Preferably, the thermal head is in an original position in a state where the recording paper is not sandwiched between the thermal head and the platen roller and axes of the thermal head and the platen roller are parallel to each other; when the recording paper is separated from the space between the thermal head and the paper pressing roller, the thermal head can generate plastic deformation under the action of the clamping piece so as to lead the thermal head to return to the original position.

Preferably, the locking piece adjusts a gap between the thermal head and the platen roller by a screw structure.

Preferably, the locking member keeps a predetermined gap between the thermal head and the platen roller when the thermal head is at the home position.

Preferably, the rear end of the holder is provided with a pivot portion pivotally connected to the base, and the elastic member applies a force to the holder toward the platen roller to press the printing device so that the printing device is in close contact with the recording paper.

Preferably, the platen roller is movably disposed on the base, and the elastic member applies a force to the platen roller toward the printing apparatus, so that the platen roller is in close contact with the recording paper.

Preferably, the elastic component is a pressure spring, a first pressure spring installation part for installing the pressure spring is arranged on the retainer, a second installation part for installing the pressure spring is arranged on the base, and the pressure spring is arranged between the first pressure spring installation part and the second installation part.

Preferably, the first pressure spring installation portion is a hollowed installation frame, the second installation portion is located at the upper end in the installation frame, and the second installation portion penetrates through the installation frame to form the installation space of the pressure spring.

By adopting the technical scheme, the utility model discloses can gain following technological effect:

1. the utility model has the advantages that through the matching of the support column and the deformation structure, the printing device can be adaptively adjusted according to the pressure transmitted by the printing paper, so that the printing pressure distribution is more uniform in the printing process, and the printing effect is better;

2. meanwhile, plastic deformation is generated by the deformation structure, and when the colloid of the paper pressing roller is subjected to local deformation due to the reaction force, the printing device can be kept unchanged by the plastic deformation, so that the heating wire of the printing device on printing paper is stable, and the printing quality is improved.

3. The holder or the paper pressing roller is movably arranged on the base, so that the printer can adapt to printing gaps required by various different pressures transmitted by paper in a wider range;

4. the supporting column section of the supporting column between the retainer and the printing device is adjustably positioned between the retainer and the printing device, so that the pretightening force of the printing device and the retainer is changed, and the printing device is better self-adaptively adjusted when uneven force is applied to the printing device.

5. Through set up the card stop on the printer, the printer is after printing at every turn, beat printing paper and break away from when pressing the paper axle, the deformation structure can reset under the effect that the support column is the fulcrum.

6. The retainer is pressurized by a compression spring, so that the compression spring can provide elastic force with high sensitivity in a thin printer.

Drawings

Fig. 1 is a schematic diagram illustrating a force applied in the prior art.

Fig. 2 is a perspective view showing a first embodiment of the present invention.

Fig. 3 is a schematic view showing the first embodiment of the present invention in an exploded state.

Fig. 4 is a perspective view showing a retainer according to a first embodiment of the present invention.

Fig. 5 shows a cross-sectional view taken along the direction a-a of fig. 2.

Fig. 6 is a schematic diagram of another embodiment of a platen roller.

The main designations in the drawings are: 1. a holder; 2. a swing frame; 3. a printing device; 31. a thermal head; 4. a paper pressing roller; 5. a fastener; 6. a base; 7. a pressure spring; 9. and (4) a bracket.

Detailed Description

To make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the drawings of the embodiments of the present invention are combined to clearly and completely describe the technical solutions of the embodiments of the present invention, and obviously, the described embodiments are some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work all belong to the protection scope of the present invention. Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention.

First embodiment

As shown in fig. 2 and 3, a thermal printer includes a base 6, a pickup roller 61, a holder 1, a printing device 3, and a platen roller 4, the printing device 3 being disposed along a width direction of a recording sheet; the printing device 3 is used for providing heat for the thermal printing paper to enable the thermal printing paper to show characters or patterns, preferably, the printing device 3 comprises a resistance heating unit, and the printing device 3 is fixed on the holding frame 1; preferably, the printing apparatus 3 further includes a swing frame 2 and a thermal head 31, the swing frame 2 is connected to the holding frame 1 at a front side thereof through a supporting post 22 and connected to the holding frame 1 at a rear side thereof through a deformation structure, the swing frame 2 can swing about the supporting post 22 as a fulcrum when the thermal head 31 receives uneven pressure applied from the recording paper to make the pressure tend to be uniform, and the deformation structure can be plastically deformed to hold the position of the swing frame 2. The heating units are arranged in a plurality, and all the heating units are arranged in a straight line along the width direction of the recording paper so as to provide heat for the thermosensitive recording paper to realize printing of characters or patterns on the recording paper. The platen roller 4 is disposed opposite to the printing apparatus 3, and rotates with a recording sheet sandwiched therebetween to feed out the recording sheet; the platen roller 4 is rotatably provided at the front end of the base 6, and rotates on the base 6 around the central axis of the platen roller 4. The periphery of the paper pressing roller 4 is colloid which can generate elastic deformation under certain pressure, and the middle part is a rigid shaft.

The rear end part of the retainer 1 is provided with a pivoting part 17 which is pivotally connected with the base 6, and the pivoting part 17 is fixed on the base 6 and rotates around the base 6. The pivoting part 17 is fixed on the base 6 through a bolt, and the retainer 1 rotates around the bolt through the pivoting part 17. The holder 1 rotates around the base 6 in various shapes, for example, the base 6 is provided with a rotating pin, and the pivot part 17 of the holder 1 is provided with a hole matched with the pin, etc. An elastic member is provided between the holder 1 and the base 6, and in a state where the recording paper is held between the printing device 3 and the platen roller 4, the elastic member brings both the printing device 3 and the platen roller 4 into close contact with the recording paper. The elastic force provided by the elastic member urges the holder 1 toward the platen roller 4 to pressurize the printing device 3. One of the preferred embodiments of the resilient member in this embodiment is a compression spring 7. The compression spring 7 is arranged in front of the retainer 1 and the base 6, and has the following specific structure: the front end part of the retainer 1 extends downwards to form a mounting frame 14, and a first pressure spring mounting part 15 is arranged on the mounting frame 14. Be equipped with the installation on the base 6 the second installation department 62 of pressure spring 7, second installation department 62 is located upper end in the installing frame 14, second installation department 62 passes installing frame 14 forms the installation space of pressure spring 7, and the position that elastomeric element set up can be manifold, can not only be limited to the position of above-mentioned scheme, for example can set up on retainer 1 etc..

The retainer 1 is provided with relief holes 13 on both sides of the front end thereof, and the relief holes 13 are provided for facilitating the mounting of the locking member 5 on the swing frame 2. The middle of the front end part of the retainer 1 is provided with a threaded hole 16, and a support column 22 is arranged on the threaded hole 16. The support post 22 is at least partially threaded for use with the threaded aperture 16. The position of the supporting column 22 relative to the holder 1 can be adjusted by a threaded structure, that is, the supporting column 22 is screwed down a little more, and the bottom of the supporting column 22 is exposed a little more from the holder 1.

Two deformation structures are arranged at the rear end part of the retainer 1, each deformation structure comprises a connecting part 12 and a deformation part 11, the connecting parts are formed by hollowing out the retainer 1, and the rear side of the swing frame 2 is fixed on the connecting parts 12. The retainer 1 is made of a cold-rolled sheet material, is poor in elasticity and is easy to generate plastic deformation.

The front side of the swing frame 2 is connected with the retainer 1 through a support column 22, the rear side of the swing frame is connected with the connecting part 12 of the deformation structure of the retainer 1 through the deformation structure, and the support column 22 is adjustable to be in abutting contact with the swing frame 2 through a thread structure and used for changing the distance between the front end part of the swing frame 2 and the front end part of the retainer 1, so that the pretightening force of the swing frame 2 relative to the retainer 1 can be changed. The swing frame 2 can swing about the support columns 22 as fulcrums when the thermal head 31 receives uneven pressure applied from the recording paper to make the pressure uniform, and the deformation structure can be plastically deformed to maintain the position of the swing frame 2. The supporting columns 22 function to transmit the pressure generated by the elastic member to the printing apparatus 3, and when the thermal head 31 receives uneven pressure applied from the recording paper, swing about the supporting columns 22 as fulcrums is generated to make the pressure uniform. Based on the function of the supporting column 22, there are many variations, such as a supporting protrusion provided on the holder 1 toward the swing frame 2; or the swing frame 2 is provided with a supporting bulge upwards towards the retainer 1, and the same function can be achieved.

Assuming that the force applied to the printing apparatus 3 by the elastic member (pressure spring 7) is F, the deforming force of the deformed structure is F1; when the rubber roller of the platen roller is used for printing, if the supporting force on the side of the density is light is F2, and the supporting force on the side of the density is deep is F2', the pressure difference between the two sides is F2' -F2, and in order to achieve better printing effect, F is more than F1> delta F. When F is larger than F1, the force of the spring can make the printing device 3 and the holder 1 deform to a certain extent, so that the force of the spring on the left and right sides can act on the printing device 3 uniformly, and the left and right pressure unevenness caused by the spring and part errors can be reduced. F1 & ltDELTA & gt can prevent the problem that the printing quality is influenced by heating position deviation caused by the change of the position of a heating unit of the printing device 3 due to the pressure difference caused by different deformation of two sides of the rubber roller, thereby ensuring the printing quality.

In the printing process of the printer, when the left and right spring force values are different or the left and right thickness of the printing paper is different, the printing device 3 can swing left and right adaptively because F is greater than F1, so that the contact stress of the printing device 3 and the recording paper is uniform, and the position of the swinging printing device 3 can be kept unchanged due to the deformation structure. As shown in fig. 1, when the adjusted printer continues to print, if the left side of the printer needs to print black with a relatively deep depth, the printing device 3 continuously heats the local part of the recording paper, the temperature of the part corresponding to the printing paper increases and becomes hot, at this time, when the printing paper is conveyed forward, the friction coefficient of the printing paper increases, so that the friction resistance F1 of the printing paper increases, the force of the paper pressing roller 4 to transfer the printing paper increases, the reaction force F2 of the printing paper also increases, because the periphery of the paper pressing roller 4 is colloid, when the reaction force F2 increases, the circular colloid section deforms (as shown in fig. 1), at this time, because of F1> Δ F, the deformation structure remains unchanged, so that the printing device 3 remains unchanged, at this time, the position of the heating unit of the printing device 3 remains unchanged, so that the original printing device 3 cannot print with a changed axis, thereby ensuring high quality printing. Therefore, the problem that the printing quality is influenced by the deviation of printing points caused by the position change of the printing device 3 in the prior art is solved.

As shown in fig. 5, when the printing apparatus 3 and the platen roller 4 do not sandwich the recording paper therebetween and the printing line of the printing apparatus 3 and the axis of the platen roller 4 are parallel to each other, the swing frame 2 is at the home position; when the printer is in a printing process, the swing frame 2 swings due to the uneven force transmitted from the recording paper, and the recording paper is separated from between the printing device 3 and the platen roller 4 under the action of the deformation structure, the retainer 1 rotates towards the platen roller 4 under the action of the elastic member, so that the swing frame 2 also rotates towards the platen roller 4, finally, one end of the swing frame 2 is firstly propped against the base 6 under the action of the clamping piece 5, the deformation structure is deformed under the pressure provided by the elastic member at the other end, the other end of the swing frame continues to move downwards, and finally, the clamping pieces 5 on the two sides of the swing frame 2 are all propped against the supporting part 63 of the base 6, so that the swing frame 2 returns to the original position. The locking member 5 maintains a predetermined gap from the platen roller 4 when the printing apparatus 3 is at the home position. The clamping and stopping piece 5 can be a screw, the screw is screwed and fixed on the swing frame 2 after passing through the abdicating hole 13 of the retainer 1, the bottom of the screw is pressed against the supporting part 63 of the base 6, and the size of the gap between the printing device 3 and the platen roller 4 when the printing device is at the original position can be adjusted through an adjusting screw. The locking piece 5 may have various structures, and may be a protrusion with a certain length which is provided upward on the supporting portion 63 of the base 6, or a protrusion provided downward on the swing frame 2 to perform the same function.

Second embodiment

In the second embodiment, the holder 1 is fixed to the base 6, the platen roller 4 is provided at the front end of the holder 9, the rear end of the holder 9 is movably provided on the base 6, and the elastic member urges the holder 9 toward the printing apparatus 3, so that the platen roller 4 is brought into close contact with the recording paper. In the second embodiment, in order to movably connect the platen roller 4 to the base 6, there are various ways, and a mounting groove may be directly formed on the base 6, and two ends of the platen roller 4 are provided with movable portions matched with the mounting groove, and an elastic member is disposed below the platen roller 4, so that the platen roller 4 is close to the printing apparatus 3 by the generated pressure. The holder 1 is the same as the first embodiment except that the mounting portion of the pressing spring 7 is eliminated as compared with the first embodiment, and therefore, the description thereof is not repeated.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification and equivalent replacement within the spirit and principle of the present invention.

Claims (14)

1. A thermal printer includes a base (6), a holder (1), a printing device (3), and a platen roller (4), the holder (1) being provided on the base (6), the printing device (3) being disposed along a width direction of a recording sheet, the platen roller (4) being disposed opposite to the printing device (3) and rotating to feed out the recording sheet with the recording sheet sandwiched therebetween; the method is characterized in that:

the front side of the printing device (3) is connected with the holder (1) through a supporting column (22), the rear side of the printing device is connected with the holder (1) through a deformation structure, when the printing device (3) receives uneven pressure applied by recording paper, swinging with the supporting column (22) as a fulcrum can be generated to enable the pressure to tend to be uniform, and the deformation structure can generate plastic deformation to keep the position of the printing device (3);

and an elastic member that is provided between the holder (1) and the base (6) and that brings the printing apparatus (3) and the platen roller (4) into close contact with the recording paper when the recording paper is held therebetween.

2. The thermal printer according to claim 1, wherein the printing device (3) comprises a swing frame (2) and a thermal head (31), the swing frame (2) is connected to the holding frame (1) at a front side thereof by a supporting column (22) and connected to the holding frame (1) at a rear side thereof by a deformation structure, the swing frame (2) is capable of swinging about the supporting column (22) as a fulcrum to make the pressure uniform when the thermal head (31) receives an uneven pressure applied from the recording paper, and the deformation structure is capable of plastically deforming to hold the position of the swing frame (2).

3. A thermal printer according to claim 2, characterised in that the strut section of the support strut (22) between the holder (1) and the swing frame (2) is adjustably positioned therebetween to vary the pretensioning of the swing frame (2) and the holder (1).

4. A thermal printer according to claim 3, characterised in that the support column (22) is adjustably mounted on the holder (1) by means of a threaded construction.

5. A thermal printer according to claim 2, characterised in that the support column (22) is located between the holder (1) and the oscillating frame (2) and is part of one of the two and projects towards the other to form an oscillating fulcrum of the oscillating frame (2).

6. A thermal printer according to claim 2, wherein the deformation structure comprises a deformation portion and a connecting portion connecting the holding frame (1) and the swing frame (2), the deformation portion being plastically deformable to maintain a swing position of the swing frame (2) when the swing frame (2) swings.

7. The thermal printer according to claim 6, wherein the deformation structure is disposed on the holder (1), and comprises a connecting portion and a deformation portion, the connecting portion is formed by hollowing out the holder (1), and the rear side of the swing frame (2) is fixed on the connecting portion.

8. The thermal printer according to claim 2, wherein in a state where no recording paper is sandwiched between said thermal head (31) and said platen roller (4) and axes of said thermal head (31) and said platen roller (4) are parallel to each other, said thermal head (31) is in a home position; when the recording paper is separated from the space between the thermal head (31) and the paper pressing roller (4), the thermal head (31) can generate plastic deformation under the action of a clamping piece (5) so that the thermal head (31) can return to the original position.

9. The thermal printer according to claim 8, wherein said locking member (5) adjusts a gap between said thermal head (31) and said platen roller (4) by a screw structure.

10. The thermal printer according to claim 9, wherein said locking member (5) keeps said thermal head (31) at a predetermined gap from said platen roller (4) when said thermal head is at said home position.

11. A thermal printer according to claim 1, wherein the rear end of said holder (1) is provided with a pivot portion (17) pivotally connected to said base (6), and said elastic member urges said holder (1) toward said platen roller (4) to press said printing device (3) into close contact with said recording paper.

12. The thermal printer according to claim 1, wherein said platen roller (4) is movably provided on said base (6), and said elastic member urges said platen roller (4) toward said printing unit (3) so as to be brought into close contact with said recording paper.

13. The thermal printer according to any one of claims 1 to 12, wherein the elastic member is a compression spring (7), a first compression spring mounting portion (15) for mounting the compression spring (7) is provided on the holder (1), a second mounting portion (62) for mounting the compression spring (7) is provided on the base (6), and the compression spring (7) is provided between the first compression spring mounting portion (15) and the second mounting portion (62).

14. The thermal printer according to claim 13, wherein the first pressure spring mounting portion (15) is a hollow mounting frame (14), the second mounting portion (62) is located at an upper end in the mounting frame (14), and the second mounting portion (62) forms a mounting space for the pressure spring (7) through the mounting frame (14).

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