JP2014148122A - Inkjet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such problems that the contact of the top of a wiping blade with the edge of a nozzle guard member of an inkjet head enlarges the abrasion loss in a contact portion to shorten the life of the wiping blade and besides, a cleaning performance deteriorates.SOLUTION: A guide part is provided to guide a wiping blade to a nozzle guard member, and two slits are formed on the wiping blade. The wiping blade is composed to use both ends thereof for wiping the nozzle guard and the middle for wiping a nozzle surface. The distance between the slits of the middle portion is made to be smaller than the wipe guard, and this portion is guided to the guide part to wipe the nozzle surface. Thereby, the contact of the wiping blade with the edge of the nozzle guard can be prevented. Besides, such procedure can prevent several times wiping by minutely shifting in the width direction of the nozzle blade every wiping and the presence of remaining unwiped portion of the nozzle surface.

Description

  The present invention relates to an inkjet printer that records an image by ejecting ink.

  2. Related Art Ink jet printers that record images by ejecting ink from an ink jet head onto a recording medium such as paper or resin film are known. Inkjet printers are required to improve performance such as high image quality, durability, and reliability. If foreign matter adheres to the nozzle surface of the inkjet head, ejection failure such as ink not being ejected may occur due to the influence. For this reason, in a general ink jet printer, the ink adhering to the nozzle surface of the ink jet head is periodically wiped with an elastic wipe blade to remove the adhering matter.

  Further, the ink jet head reciprocates in the width direction of the recording medium with an interval of several millimeters with respect to the recording medium. If there is abnormal conveyance such as distortion of the recording medium, the inkjet head and the recording medium come into contact with each other. The nozzle plate of the ink jet head is provided with a fine nozzle on a resin plate. The contact between the recording medium and the ink jet head may cause a non-reproducible scratch on the nozzle. If ejection defects occur due to scratches, the ink jet head must be replaced. Therefore, the structure provided with the guard member of the nozzle which guards a nozzle is considered.

  For example, Japanese Patent No. 3233164 is cited as a conventional technique. In this technique, convex guard members are arranged on both sides of the nozzle array on the nozzle surface of the head, so that even when a recording medium comes into contact, it is difficult to directly hit the nozzle and prevent scratches.

Japanese Patent No. 3233164

  In the prior art, the guard member of the nozzle is a plate-like plate fixed on each side of the nozzle row. Therefore, when wiping the nozzle with the wipe blade, the wipe blade will ride on the guard member unless it is positioned accurately. When the wipe blade rides on the guard member, the nozzle surface and the guard member are different in height, so that the corner portion due to the step cannot be sufficiently wiped off and dust may accumulate. Further, if the wipe blade is hit with a sharp corner of the edge portion of the guard member and wiped while being in contact with the wipe blade, the contact portion of the wipe blade with the guard member may be damaged. In addition, the durability of the wipe blade is inferior. The damaged part cannot be wiped out sufficiently, and there is a risk that dust will remain.

  In order to solve such a problem, the present invention provides an inkjet printer including an inkjet head and a wipe blade that can record high-quality images and has high durability and reliability.

  An inkjet printer according to the present invention includes a recording head having a nozzle row composed of a plurality of nozzles that eject ink, a carriage that mounts the recording head and moves in the main scanning direction, and a direction that intersects the main scanning direction. A wipe blade for wiping the nozzle surface side where the nozzles of the recording head are formed while moving, and a nozzle surface of the recording head where the nozzles are provided, and an opening at a portion corresponding to the nozzle row In the ink jet printer having the nozzle guard, the wiper blade has a tip that is wiped off at both sides of the nozzle row along the row direction and a portion that wipes off the nozzle surface. The opening of the nozzle guard is one side in the row direction of the nozzle row and starts wiping. A guide portion having a width gradually increasing toward the end in the row direction of the nozzle guard, and when wiping the recording head with the wipe blade, a portion for wiping the nozzle surface is When the portion to be wiped contacts the side wall of the guide portion, the nozzle surface is wiped by curving in the direction intersecting the moving direction of the wipe blade and the moving direction according to the contact position of the side wall, When the portion for wiping the nozzle surface does not contact the side wall of the guide portion, the nozzle surface is wiped by being curved in the moving direction of the wipe blade.

  According to the present invention, the difference in the amount of wear depending on the location of the tip of the wipe blade can be reduced to prevent an excessive amount of wear on a specific portion, and the life can be extended. An improved inkjet printer having a durable and reliable inkjet head and wipe blade that can record high-quality images can be provided.

FIG. 1 is a schematic view of an ink jet printer. FIG. 2 is a schematic view of the wiping mechanism. FIG. 3 is a diagram illustrating an example of a nozzle guard. FIG. 4 is a diagram illustrating an example of the relationship between the nozzle guard and the wipe blade. FIG. 5 is a diagram for explaining the operation of the wipe blade. FIG. 6 is a block diagram of the ink jet printer. FIG. 7 is a flowchart for explaining the operation of the wipe sequence.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view of an ink jet printer. As shown in FIG. 1, the ink jet printer 1 of the present embodiment arranges a recording medium 50 horizontally and conveys it in the depth direction of the paper surface of FIG. 1, ejects ink from an ink jet recording head 9, and records the recording medium. Images, characters and the like corresponding to the recording data are recorded on the surface of 50. The recording medium 50 is paper, a resin film, or the like. This depth direction in the drawing is called the sub-scanning direction.

  The ink jet printer 1 includes a transport unit 4 that transports the recording medium 50. In addition, a recording unit head 9 and a plurality of recording heads 9 are mounted, a carriage 8 that performs recording by reciprocating scanning in a direction orthogonal to the conveyance direction of the recording medium 50, a wipe unit 10 that wipes the recording head 9, and a recording A capping unit 12 that caps the head 9 is provided. The direction of reciprocating scanning is called the main scanning direction. The ink jet printer 1 includes control means for controlling the entire apparatus including reception of recording data and control of recording operation.

  The transport unit 4 includes a plurality of transport roller pairs 3 that are rotated by a motor 5 around a horizontal axis along the paper surface on a substantially flat platen 2 that extends in the depth direction of the paper surface of FIG. The transport roller pair 3 includes a grid roller that is rotatably supported around a rotation axis parallel to the rotation axis, and a pinch roller that is energized by the grid roller. The recording medium 50 is conveyed while being sandwiched between the grid roller and the pinch roller. As the grid roller rotates, the recording medium 50 is conveyed from the depth direction to the near side.

  The carriage 8 is provided above the transport unit 4, the wipe unit 10, and the capping unit 12 so as to be movable along a carriage rail 7 that extends in a direction orthogonal to the transport direction of the recording medium 50. A motor 6 is also provided for reciprocally moving the carriage 8 on the carriage rail 7 so as to be capable of position control and speed control. A linear scale (not shown) is provided along the carriage rail 7, and a linear sensor for detecting the scale of the linear scale is provided in the carriage 8. The position of the carriage 8 can be detected, and the positions of the plurality of recording heads 9 fixed to the carriage 8 at a fixed position can be detected accordingly.

  Further, a detachable ink cartridge 14 for supplying recording ink to the recording head 9 is provided, and the ink cartridge 14 and the recording head 9 are connected by an ink tube 15 for supplying ink.

  In the present embodiment, the ink cartridge 14 is provided with a plurality of colors of ink for performing color recording, and can be supplied to the recording head 9 for each color via a plurality of ink tubes 15 as pipes. ing. The ink cartridge 14 is provided with a plurality of ink tanks corresponding to each ink, and each ink is accommodated in a corresponding ink tank.

  The carriage 8 is provided with a plurality of recording heads 9 on the lower surface side according to the ink color and recording range, and the ink supplied from the ink tube 15 is distributed to the recording heads 9 that perform recording of the same color. Supplied. The carriage 8 is provided with a cooling fan 16 for keeping the temperature of each recording head 9 within an appropriate temperature range.

  Although details of the recording head 9 are not shown, an ink chamber for supplying ink to each nozzle and an ejection mechanism using a piezoelectric element are provided. The recording head 9 is configured to be able to perform an idle driving operation in which ink is ejected and the ink meniscus of the nozzle is finely oscillated by an ejection mechanism using the piezoelectric element. The ink jet printer 1 records an image by ejecting ink from nozzles outside the image forming range. Further, the nozzles can be provided with an appropriate number and arrangement pitch according to the configuration of the ejection mechanism, the recording pixel pitch, and the like. For example, a large number of nozzles such as 256 can be arranged. For example, the recording head 9 may use a piezoelectric element as a recording element, or may be a recording head using a heater as a recording element.

  The position control and speed control of the motor 6 are performed according to the control signal of the control means. During the recording operation, the motor 6 is controlled so that the recording head 9 reciprocates on the recording medium 50 at a predetermined speed. Further, the motor 6 can move the recording head 9 to a predetermined wiping position of the wipe unit 10 during the cleaning operation.

  In this embodiment, the wipe unit 10 wipes the nozzle surface of the recording head 9. Further, the capping unit 12 performs suction cleaning for cleaning the recording head 9 by sucking the ink of the recording head 9 from the nozzles to the outside. Also, the ink is prevented from drying by capping when not in use. The schematic configuration of the capping unit 12 includes a cap 11, a cap driving unit (not shown), a suction pump 13, a pump driving unit (not shown), an air release valve (not shown), and an air release valve drive unit (not shown). .

  Among these, at least the cap 11 is provided for each recording head 9. However, the cap driving unit, the suction pump 13, the air release valve, and the air release valve drive unit may be provided for each of the plurality of caps 11 when each operation can be made common for each recording head 9. .

  The cap drive unit moves up and down to selectively switch the position of the cap 11 in the vertical direction, and includes, for example, appropriate mechanical, electromagnetic, and fluid lifting means. Therefore, the cap drive unit moves the cap 11 up and down with respect to the recording head 9 which is moved on the carriage rail 7 by the motor 6 and positioned above the capping unit 12. The state in which the nozzle surface is sealed and the state in which the sealing is released can be switched.

  The suction pump 13 is for sucking contents such as air and ink in the suction space and discharging them to the outside of the suction space, and an appropriately configured fluid pump such as a rotary pump can be adopted. A liquid passing means for passing ink from the ink cartridge 14 to the recording head 9 and a suction pump 13 are used here. The suction pump 13 has a suction port connected to the suction tube and a discharge port connected to the discharge tube. The other end of the discharge pipe is connected to a waste liquid bottle (not shown).

  The wipe unit 10 wipes and cleans the nozzle surface of the recording head 9 by moving the wipe blade relative to the nozzle surface of the recording head 9 while the recording head 9 is moved above the wipe unit 10. To do.

FIG. 2 is a schematic view of the wiping mechanism. A wipe unit 10 for wiping the recording head 9 will be described.
A wipe blade 18 is fixed to the belt 17. The belt 17 rotates in the direction of arrow 19. The wipe blade 18 fixed to the belt 17 moves with the rotation. The tip of the wipe blade 18 comes into contact with the recording head 9 so that the nozzle surface is wiped. A cleaning tank 21 that stores a cleaning liquid 22 is disposed below the recording head 9 and the belt 17. A cleaning member 23 that contacts the wipe blade 18 is provided in the cleaning tank 21. The cleaning member 23 is a porous member such as a sponge. The cleaning member 23 is immersed in the cleaning liquid 22 and moves while the wipe blade 18 is in contact with the cleaning member 23, thereby cleaning the dust attached to the wipe blade 18. The wipe blade 18 is cleaned with the cleaning liquid 22 stored in the cleaning tank 21. Further, by wiping the nozzle surface with the cleaning liquid 22 attached, it is easy to remove ink or the like firmly attached to the nozzle surface. The wipe blade 20 indicated by a dotted line shows a state where it is in contact with the cleaning member 23. The attached object is removed while the tip of the wipe blade 20 is curved and comes into contact with the cleaning member 23.

  FIG. 3 is a diagram illustrating an example of a nozzle guard. The nozzle guard 24 is a metal plate and is fixed on the nozzle surface 30 of the recording head 9. The nozzle face 30 and the nozzle guard 24 are airtightly fixed with an adhesive. Since the cap of the capping unit 12 is in close contact with the nozzle guard 24, it is desirable that there is no wiping residue. The nozzles 29 of the recording head 9 are arranged in rows, and guard portions 27 of the nozzle guard 24 are provided on both sides along the nozzle rows. That is, the guard part 27 is provided so that the nozzle row is placed between them. Due to the difference in height between the guard portion 27 and the nozzle surface 30, the nozzle surface 30 can prevent contact with the recording medium. Further, a part of the wipe blade 18 moves along the side wall of the opening of the nozzle guard 24. One end 26 side of the opening is the wipe start direction of the wipe blade 18, and the other end 28 side is the wipe end direction of the wipe blade 18. On one end 26 side, a guide portion 25 for guiding the movement of the wipe blade 18 is provided. The guide portion 25 is configured to gradually narrow from the one end 26 toward the other end 28. The nozzle row is not located in the portion sandwiched between the guide portions 25, but is located in the portion corresponding to the guard portion 27 in which the openings are arranged at regular intervals. Otherwise, the wiper blade 18 is guided by the guide portion 25, so that a portion that cannot be wiped may be generated.

  Here, the nozzle guard 24 includes an opening and has an integral structure. However, the nozzle guard 24 may have a structure of two bodies sandwiching the opening. That is, a nozzle row is placed in between, and plate-like nozzle guards are fixed to both sides thereof. The two plates are separate. That is, a configuration in which the nozzle guard 24 is not provided on the nozzle surface on the extended line of the nozzle row is also possible. For example, a configuration may be adopted in which a corner of a rectangular nozzle guard is cut off and a pentagonal shape with the portion as a guide portion is formed.

  Further, since the nozzle guard 24 is symmetric with respect to the nozzles 29 arranged in a row, the wipe blade 18 moves along the edge of the guide portion 25 on either side, that is, the side wall of the opening. Even in this case, the nozzle surface 30 including the nozzle row can be accurately wiped off.

  FIG. 4 is a diagram illustrating an example of the relationship between the nozzle guard and the wipe blade. The wipe blade 18 includes a base portion 31, a first wipe portion 32, a second wipe portion 33, and a third wipe portion 34. A first slit 35 is provided between the first wipe part 32 and the second wipe part 33, and a second slit 36 is provided between the second wipe part 33 and the third wipe part 34. The first slit 35 and the second slit 36 are thin U-shaped cuts. The slit, that is, the U-shaped groove here has a width, but this is not a shape and the slit width may not be. However, if there is no width, the ink can easily enter and the ink can be removed. Since it may be difficult, it is better to have a slit width if possible. Further, the reason why the second wiper portion 33 can be freely curved is that it is separated from the first wiper portion 32 and the third wiper portion 34 at both ends in this way. If you are in contact with the scale, you may be taken with you.

  The base 31 is fixed to the belt 17. The first wipe portion 32, the second wipe portion 33, and the third wipe portion 34 are made of a resin such as rubber, and are elastic, so that they are curved when coming into contact with the nozzle surface 30 or the nozzle guard 24, and the contact is released. Then the curve disappears.

  A distance 37 between the first wiper portion 32 and the third wiper portion 34 is configured to be approximately equal to a distance 39 between the guard portions 27. Further, the widths of the first wipe portion 32 and the third wipe portion 34 are configured to be wider than the width of the guard portion 27, and even if a slight misalignment occurs when the recording head 9 is wiped with the wipe blade 18, the entire surface is wiped. It has a width that can be. The width 38 of the second wipe portion 33 is narrower than the distance 39 between the guard portions 27, but is wider than half thereof. This is because the nozzle row can always be wiped even if the position is displaced during wiping.

  FIG. 5 is a diagram for explaining the operation of the wipe blade. When wiping the nozzle surface 30 of the recording head 9, the wipe blade 18 is slid from one end 26 side to the other end 28 side of the opening from end to end of the recording head 9. Move in the direction of the arrow in the figure. In the figure, the wipe blade 18 is gradually moving.

  Since the second wipe part is made of an elastic resin, even if misalignment or the like occurs, the second wipe part 33 is bent and guided by the guide part 25 while sliding along the edge of the guard part 27 on the left side of the drawing. Moving. Thus, since the second wipe 33 is bent, it can slide so that the tip of the nozzle guard 24 does not come into contact with the corner of the opening, so that wear can be reduced and the life of the wipe blade 18 can be extended. . In addition, when the second wiper 33 is disposed on the right side of the drawing, the second wiper 33 is guided by the guide 25 and moves while sliding along the edge of the guard 27 on the right side of the drawing. Since it does not ride on the edge, the tip of the wipe blade 18 is not damaged by a sharp edge. Further, since the second wipe 33 is bent along the edge of the opening, that is, along the side wall of the opening, the second wipe 33 does not ride on the nozzle guard 24 and the nozzle row can be wiped without fail.

  FIG. 6 is a block diagram of the ink jet printer. The control unit 40 is a control unit including a CPU that executes processing operations such as calculation, control, determination, and setting. The control means 40 operates according to a control program stored in the ROM 41. The RAM 43 is used as a recording data buffer, a work area for processing by the control means 40, and the like. The carriage movement motor drive circuit 43 operates under the control of the control means 40 and drives the motor 6 that moves the carriage 8. The carriage position detection sensor 44 is a linear sensor that detects a scale of a linear scale arranged along the carriage rail 7. The position of the carriage 8 is calculated and acquired based on the sensor output. The head drive circuit 45 is controlled by the control means 40. The recording head 9 is operated via the head driving circuit 45. When a plurality of recording heads 9 are mounted, the control unit 40 and the head driving circuit 45 can drive each recording head 9 individually. Based on the information input from the control means 40, the head drive unit 45 generates ink ejection timing or non-ejection timing for each recording head 9 and drives the recording head 9. When ink ejection is performed, an ON waveform is generated. When ink ejection is not performed, an OFF waveform is generated and transferred to each recording head 9. The ejection timing is determined according to the position of the carriage 8.

  The recording medium transport unit 46 operates under the control of the control unit 40. The recording medium conveyance unit 46 includes a motor 5 and a conveyance roller pair 3. The recording medium 50 is conveyed by operating the conveying roller pair 3. The wipe blade moving motor drive circuit 47 operates under the control of the control means 40. The wipe blade moving motor drive circuit 47 drives a motor that moves the belt 17.

  Each function of the inkjet printer 1 is controlled by the control means 40. Further, by storing information on wiping operation conditions in the control means 40 in advance, a predetermined wiping operation can be performed. Examples of the wiping conditions include the moving speed of the wipe blade 18 and the number of rubbing times of the nozzle surface 30 of the recording head 9 of the wipe blade 18.

FIG. 7 is a flowchart for explaining the operation of the wipe sequence.
When wiping the nozzle surface 30 of the recording head 9, wiping is performed at least twice. That is, the nozzle surface 33 exposed from the opening of the nozzle card 24 and the surface of the nozzle guard 24 can be wiped by sliding along the edge of each side of the guard portion 27 of the nozzle guard 24. In the example, this is done three times. The first time is right-handed, the second time is left-handed, and the third time is wiping away from the center. This is to allow an allowable range of misalignment due to attachment error and backlash. Further, when the nozzle blade 18 is divided into three parts and there is a gap between them, it is necessary to wipe the part corresponding to the gap part between each other by wiping at least twice. Need to be wiped out. The operation of the wipe blade 18 will be described using a flowchart.

In step S1, the recording head 9 is first moved to the first wipe position. The position of the carriage 8 is acquired by the control means 40, the carriage 8 is moved to a position facing the wipe blade 18, and the process proceeds to the next step 2. The carriage 8 is moved aiming at the right end of the allowable range of the wipe position of the wipe blade 18 and the recording head 9.
In step S2, the first wipe is performed. The belt 17 is rotated under the control of the control unit 40. The number of first wipes may be multiple. Next, the process proceeds to step S3.

In step S3, the recording head 9 is moved to the second wipe position. The position of the carriage 8 is acquired by the control means 40, the carriage 8 is moved, and the process proceeds to the next step 4. The carriage 8 is moved aiming at the left end of the allowable range of the wipe position of the wipe blade 18 and the recording head 9.
In step S4, a second wipe is performed. The belt 17 is rotated under the control of the control unit 40. The number of second wipes may be multiple. Next, the process proceeds to step S5.

In step S5, the recording head 9 is moved to the third wipe position. The position of the carriage 8 is acquired by the control means 40, the carriage 8 is moved to a position facing the wipe blade 18, and the process proceeds to the next step 6. The carriage 8 is moved aiming at the center of the allowable range of the wipe position of the wipe blade 18 and the recording head 9.
In step S6, a third wipe is performed. The belt 17 is rotated under the control of the control unit 40. The number of third wipes may be multiple.
This completes the wiping operation of one recording head 9, but this sequence may be performed a plurality of times depending on the degree of contamination of the recording head 9.

  Since the wipe blade 18 can be guided along the edge of the opening of the wipe guard 18, that is, the side wall as described above, the wipe blade 18 is not detached from the portion to be wiped, and the tip of the wipe blade 18 is also removed. Can be used for a long time. Moreover, if it is not consumed, the finish of the wiping operation is good, and deterioration of the image quality can be prevented.

  The present invention can be used in a printer having an inkjet head.

DESCRIPTION OF SYMBOLS 1 Inkjet printer 2 Platen 3 Carrying roller pair 5 Motor 6 Motor 7 Carriage rail 8 Carriage 9 Recording head 10 Wipe unit 13 Suction pump 17 Belt 18 Wipe blade 21 Cleaning tank 22 Cleaning liquid 24 Nozzle guard 25 Guide part 27 Guard part 30 Nozzle surface 31 Base portion 32 First wipe portion 33 Second wipe portion 34 Third wipe portion 35 First slit 36 Second slit 50 Recording medium

Claims (4)

A recording head having a nozzle row composed of a plurality of nozzles for ejecting ink, a carriage mounted with the recording head and moving in the main scanning direction, and moving in a direction intersecting the main scanning direction while moving the recording head A wipe blade for wiping the nozzle surface side on which the nozzles are formed, and a nozzle guard fixed to the nozzle surface on which the nozzles of the recording head are provided and having openings at portions corresponding to the nozzle rows. In an inkjet printer,
The wipe blade is divided into a portion for wiping both sides of the nozzle row along the row direction and a portion for wiping the nozzle surface, and the tip is divided into three portions, and the opening of the nozzle guard The portion includes a guide portion that gradually increases in width toward the end of the nozzle guard in the row direction on one side of the nozzle row in the row direction and starts wiping.
When the recording head is wiped with the wipe blade, the portion for wiping the nozzle surface is in accordance with the contact position of the side wall when the portion for wiping the nozzle surface is in contact with the side wall of the guide portion. When the nozzle surface is wiped by being curved in a direction intersecting with the moving direction of the wipe blade and in the moving direction, and the portion wiping the nozzle surface does not contact the side wall of the guide portion, An ink jet printer that is curved in a moving direction and wipes the nozzle surface.   When the recording head is wiped with the wipe blade, the carriage is moved to at least two positions with respect to one recording head, and the inkjet head is wiped at each position.   3. The ink jet printer according to claim 1, wherein the tip of the wipe blade is divided into the three portions by a U-shaped groove. 4.   4. The nozzle guard according to claim 1, wherein the nozzle guard is a flat plate having a uniform thickness at a portion facing the nozzle surface, and the opening is a hole surrounding the nozzle row. The inkjet printer as described in.

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