JP6006140B2 - inkjet printer - Google Patents

Description

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

  2. Related Art Inkjet printers that record images by ejecting ink from an inkjet head onto a recording medium such as paper or a 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. Therefore, in a general ink jet printer, ink or the like adhering to the nozzle surface of the ink jet head is periodically wiped with an elastic wiper blade such as rubber 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. A general nozzle plate of an 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 this scratch, the ink jet head must be replaced. Therefore, the structure provided with the guard member which guards a nozzle on the nozzle surface 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 row provided on the nozzle surface of the ink jet head, so that even when the recording medium comes into contact, it is difficult to directly hit the nozzle and prevent scratches. Is.

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. If the wipe blade rides on the guard member, the nozzle surface and the guard member are different in height, so that the corner portion of the step between the nozzle surface and the guard member 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 abrasion progressing speed of the wipe blade is increased. The damaged part cannot be wiped out sufficiently, and there is a risk that dust will remain. Further, even if the wipe blade is normal, if it rides on the guard member, there is a problem that a portion that cannot be wiped off by the wipe blade is formed on the surface of the guard member, and a lump of ink remains. When a lump of ink remains, when it is capped, air leaks from the ink and ink cannot be sucked.

  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 an inkjet head having a nozzle row composed of a plurality of nozzles that eject ink, a carriage that mounts the inkjet head and moves in the main scanning direction, and a direction that intersects the main scanning direction. In an inkjet printer, comprising: a wipe blade that wipes a nozzle surface on which the nozzles of the inkjet head are formed while moving; and a nozzle guard that is fixed to the nozzle surface and includes an opening in a portion corresponding to the nozzle row The wipe blade has a first wipe blade and a second wipe blade, and the first wipe blade is wider than the width of the nozzle guard and has a tip divided into three parts. Parts where both ends of the three parts wipe only the surface of the nozzle guard A central portion of the three portions is a portion for wiping the surface of the nozzle guard and the nozzle surface, and the second wipe blade is wider than the width of the nozzle guard, and is a porous resin. In the case where the inkjet head is wiped with the wipe blade, wiping is performed in at least two positions where the relative positions of the inkjet head and the wipe blade are different in the width direction of the inkjet head. One wipe blade wipes the surface of the nozzle guard and the surface of the nozzle guard, and the second wipe blade wipes the surface of the nozzle guard without wiping the nozzle surface.

  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 capable of recording high-quality images can be provided.

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

Embodiments of the present invention will be described with reference to the drawings.
FIG. 7 is a schematic diagram of an inkjet printer. The ink jet printer 39 of the present embodiment fixes a recording medium on the platen 41 and ejects ink while reciprocating the carriage 40 on which the ink jet head is mounted in the width direction of the recording medium, that is, the main scanning direction. Images, characters, etc. corresponding to the recording data are recorded on the surface of the recording medium. The recording medium is paper, resin film, or the like.

  The carriage 40 moves along the rail 45. The carriage 40 is fixed to a carriage belt 44, and the carriage belt 44 is driven by a motor 43. On one end side of the platen 41, a cap unit 46 that seals the ink jet head and sucks ink as necessary is disposed. A wipe unit 1 for cleaning the inkjet head is disposed on the other side.

  The ink jet printer 39 includes a transport roller 42 that transports a recording medium. A plurality of transport rollers 42 are arranged along the rail 45. The recording medium conveyance direction is referred to as a sub-scanning direction. The transport roller 42 includes a rotating grid roller and a pinch roller that is energized by the grid roller. The recording medium is conveyed while being sandwiched between the grid roller and the pinch roller. The recording medium is conveyed by the rotation of the grid roller.

  A linear scale (not shown) is provided along the rail 45, and a linear sensor for detecting the scale of the linear scale is provided in the carriage 40. The position of the carriage 40 can be detected, and the positions of a plurality of inkjet heads fixed to the carriage 40 at a fixed position can also be detected accordingly.

  Although details of the inkjet head are not shown, an ink chamber for supplying ink to each nozzle and an ejection mechanism using a piezoelectric element are provided. The ink-jet head 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 39 records an image by ejecting ink from the 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 inkjet head may use a piezoelectric element as the recording element, or may be an inkjet head using a heater as the recording element.

  FIG. 1 is a schematic view of a wiping mechanism. The wipe unit 1 wipes the nozzle surface 22 provided with a plurality of nozzles of the ink jet head 6 with the first wipe blade 3 and the second wipe blade 4. The inkjet head 6 in the drawing depicts a state in which the nozzle surface 22 is wiped by the first wipe blade 3 and the second wipe blade 4 along the nozzle row direction.

  The first wipe blade 3 is an elastic body made of resin such as rubber, and wipes the nozzle surface 22 while bending the tip. The second wipe blade 4 is a porous elastic body made of resin, and wipes the nozzle surface 22 while bending the tip. The second wipe blade 4 is immersed in the cleaning liquid 8 in the liquid tank 7 to store the cleaning liquid 8 and wipe the nozzle surface 22. The nozzle surface 22 is wiped by the second wipe blade 4 with the cleaning liquid 8 so that the thickened ink can be sufficiently dissolved and removed. A porous member base 9 is disposed in the liquid tank 7 in order to sufficiently remove ink and the like adhering to the first wipe blade 3 and the second wipe blade 4. The table 9 is immersed in the cleaning liquid 8 and moved while the first wipe blade 3 and the second wipe blade 4 are in contact with each other, thereby removing the adhered ink and the like. By providing irregularities on the upper surface of the table 9 and changing the angle at which the wipe blade strikes, the deposits can be further removed.

  The belt 2 is an endless belt that fixes the first wipe blade 3 and the second wipe blade 4 and rotates in the direction of the arrow 5. A wipe blade drawn by a dotted line 10 indicates a state in which the first wipe blade 3 or the second wipe blade 4 is in contact with the table 9 and indicates that the tip is in contact while being curved.

  FIG. 2 is a diagram illustrating an example of the relationship between the inkjet head and the wipe blade. On the nozzle surface side of the inkjet head 6, a nozzle guard 20 is fixed in close contact with the nozzle surface 22. The nozzle row 19 has a plurality of nozzles arranged in a row along the longitudinal direction of the nozzle surface 22 of the inkjet head 6. A side wall 21 is provided on the inner periphery of the nozzle guard 20 in a direction perpendicular to the nozzle surface 22.

  A blade fixing portion 11 is provided at the base end of the first wipe blade 3, and a rubber blade divided into a first blade 12, a second blade 13, and a third blade 14 is provided at the tip. A first slit 15 and a second slit 16 are provided between them. The blade fixing part 11 is fixed to the belt 2. The first slit 15 and the second slit 16 are U-shaped grooves, and the first blade 12, the second blade 13, and the third blade 14 are separated so as not to contact each other.

  A blade fixing portion 17 is provided at the base end of the second wipe blade 3, and a fourth blade 18 of a porous member made of resin, for example, sponge, is provided at the tip. The blade fixing part 17 is fixed to the belt 2.

  The width of the second blade 13 is shorter than the distance between the inner circumferences along the nozzle row 19 of the nozzle guard 20. The nozzle surface 22 can be wiped by the second blade 13. Further, the width of the first blade 12 and the third blade 14 is wider than the width of the nozzle guard 20 along the nozzle row 19, and the surface of the nozzle guard 20 along the nozzle row 19 can be wiped off. Since the surface of the nozzle guard 20 corresponding to the first slit 15 and the second slit 16 is not wiped off, the wiper is wiped off by changing the relative position in the width direction of the first wipe blade 3 and the inkjet head 6.

  The width of the fourth blade 18 of the second wipe blade 4 is wider than the width of the nozzle guard 20. Even when the relative position of the first wipe blade 3 and the inkjet head 6 in the width direction changes, the entire surface can be wiped off.

  FIG. 3 is a diagram illustrating an example of wiping the inkjet head with a wipe blade. When the inkjet head 6 is wiped by the second wipe blade 4, the second wipe blade 4 contacts the surface of the nozzle guard 20, but does not contact the nozzle surface 22. The tip of the fourth blade 18 is deformed, and a convex portion 23 is formed at the portion between the inner circumferences of the nozzle guard 20, but does not contact the nozzle surface 22. The second wipe blade 4 mainly wipes the surface of the nozzle guard 20. By sufficiently removing the ink adhering to this portion with the cleaning liquid, the close contact with the cap is ensured, and the problem of air leakage during suction is eliminated.

FIG. 4 is a block diagram of the ink jet printer.
The control unit 31 is a control unit including a CPU that executes processing operations such as calculation, control, determination, and setting. The control means 31 operates according to a control program stored in the ROM 24. The RAM 25 is used as a recording data buffer, a work area for processing by the control means 31, and the like. The carriage movement motor drive circuit 26 operates under the control of the control means 31 and drives a motor that moves the carriage 40 on which the inkjet head 6 is mounted. The carriage position detection sensor 27 is a linear sensor that detects the scale of a linear scale arranged along the rail 45 that guides the movement of the carriage 40. The position of the carriage 40 is calculated and acquired based on the sensor output. The head drive circuit 28 is controlled by the control means 31. The inkjet head 6 is operated via the head drive circuit 28. When a plurality of inkjet heads 6 are mounted, the control unit 31 and the head drive circuit 28 can drive each inkjet head 6 individually. The head drive circuit 28 generates ink ejection timing or non-ejection timing for each inkjet head 6 based on information input from the control means 31 and drives the inkjet head 6. 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 inkjet head 6. The ejection timing is determined according to the position of the carriage 40.

  The recording medium transport unit 29 operates under the control of the control unit 31. The recording medium transport unit 31 includes a roller 42 that transports the recording medium. The roller 42 is driven by a motor to convey the recording medium. The wipe blade moving motor drive circuit 30 operates under the control of the control means 31. The wipe blade moving motor drive circuit 30 drives a motor that moves the belt 2.

  Each function of the ink jet printer is controlled by the control means 31. In addition, by storing information on wiping operation conditions in the control unit 31 in advance, a predetermined wiping operation can be performed. Examples of the wiping condition include the moving speed of the first wipe blade 3 and the second wipe blade 4 and the number of times of wiping the nozzle surface 22.

FIG. 5 is a flowchart for explaining the operation of the wipe sequence.
When wiping the nozzle surface 22 of the inkjet head 6, wiping is performed at least twice. That is, the entire guard surface of the nozzle guard 20 is wiped off. By wiping a plurality of times, the nozzle surface 22 and the surface of the nozzle guard 20 exposed from the opening of the nozzle card 20 can be wiped off. In the example, it is done twice. The first time is wiped right and the second is wiped left. It should be possible to cover the allowable range of misalignment due to mounting errors and rattling. In addition, when the tip of the first wipe blade 3 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. Therefore, multiple wiping is required.

  In step S1, the inkjet head 6 is first moved to the first wipe position. The position of the carriage 40 is acquired by the control means 31, the carriage 40 is moved to a position facing the first wipe blade 3, and the process proceeds to the next step 2. The first wipe blade 3 and the second wipe blade 4 move the carriage 40 aiming at the right end of the allowable range of the wipe position of the inkjet head 6.

In step S2, the first wipe is performed. The belt 2 is rotated under the control of the control means 31. The number of first wipes may be multiple. Next, the process proceeds to step S3.
In step S3, the inkjet head 6 is moved to the second wipe position. The control unit 31 acquires the position of the carriage 40, moves the carriage 40, and proceeds to the next step 4. The carriage 40 is moved aiming at the left end of the allowable range of the wipe position of the first wipe blade 3, the second wipe blade 4, and the inkjet head 6.

In step S4, a second wipe is performed. The belt 2 is rotated under the control of the control means 31. The number of second wipes may be multiple. Next, the process proceeds to step S5.
In step S5, the first and second wipes are counted. Next, the process proceeds to step S6.
In step S6, it is determined whether or not the counted number of wipes exceeds a predetermined number. If not, the process proceeds to step S1 to perform the wipe process again. If it exceeds, the wiping process is terminated.

  The number of times of wiping is a preset value, and the number of times that the nozzle surface can be sufficiently wiped is obtained through experiments and stored in the ROM 24. Multiple wipe modes may be created, and the number of times may be changed each time. This is because there are cases where it is necessary to increase the number of times depending on the degree of contamination. This completes the wiping operation of one inkjet head 6.

  By cleaning the nozzle surface 22 and the surface of the nozzle guard 20 of the inkjet head 6 as described above, it is possible to prevent ejection failure and to prevent air leakage during sealing. Further, by wiping at the correct position, the consumption of the tip of the first wipe blade 3 or the second wipe blade 4 can be suppressed, and it 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.

  FIG. 6 is a diagram illustrating the positional relationship of the wipe blade. An axis 32 is an axis indicating elapsed time, and time elapses in the right direction in the figure. A period 33 indicates a period during which the belt 2 rotates once. The left end of the period 33 is a start point of one rotation, and the right end is an end point.

  Initially, the second wipe blade 4 is immersed in the cleaning liquid 8 for the period indicated by the arrow 36. Next, the inkjet head 6 is wiped off for a period indicated by an arrow 37. Next, it is immersed in the cleaning liquid 8 for the period indicated by the arrow 38. The first wipe blade 3 is immersed in the cleaning liquid 8 for the period indicated by the arrow 34. Next, the inkjet head 6 is wiped off for a period indicated by an arrow 35. When the wiping process is not performed, the second wipe blade 4 is in a state of being immersed in the cleaning liquid 8.

  The inkjet head 6 is first wiped with the second wipe blade 4, and then the inkjet head 6 is wiped with the first wipe blade 3. Since this wiping operation is performed at least twice by changing the relative position, the firmly adhered ink can be removed without wiping off.

  Here, it can be set as the structure further provided with a 3rd wipe blade. The third wipe blade is, for example, a rubber material, and is preferably the same as the first wipe blade 3 that is divided into three at the tip. In addition, by wiping with the third wipe blade after the first wipe blade 3 after the first wipe blade 3, the wipe is wiped with the same type of wipe blade immediately after being wiped with the third wipe blade 4. it can. That is, since it is performed twice, it is possible to prevent wiping. Further, the third wipe blade may be slightly shifted from the first wipe blade 3 in the width direction. By doing so, wiping leakage due to the slit portion can be eliminated. In this case, if the shift amount is not less than the width of the first slit 15 and the second slit 16 and not more than the width of the second blade 13, the inkjet head 6 can be wiped without wiping if the belt 2 is rotated once. .

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

DESCRIPTION OF SYMBOLS 1 Wipe unit 3 1st wipe blade 4 2nd wipe blade 6 Inkjet head 7 Liquid tank 8 Cleaning liquid 19 Nozzle row 20 Nozzle guard 22 Nozzle surface 39 Inkjet printer 40 Carriage 41 Platen 42 Carrying roller 44 Carriage belt 45 Rail 46 Cap unit

Claims (5)

An inkjet head having a nozzle row composed of a plurality of nozzles for ejecting ink, a carriage mounted with the inkjet head and moving in a main scanning direction, and moving in a direction crossing the main scanning direction. In an inkjet printer comprising: a wipe blade for wiping the nozzle surface on which the nozzle is formed; and a nozzle guard fixed to the nozzle surface and provided with an opening in a portion corresponding to the nozzle row,
The wipe blade has a first wipe blade and a second wipe blade;
The first wipe blade is wider than the width of the nozzle guard and has a tip divided into three parts, and both end parts of the three parts wipe only the surface of the nozzle guard. In addition, the central part of the three parts is a part that wipes the surface of the nozzle guard and the nozzle surface,
The second wipe blade is wider than the width of the nozzle guard and is made of a porous resin.
When wiping the ink jet head with the wipe blade, in the width direction of the ink jet head, wiping is performed at at least two positions where the relative positions of the ink jet head and the wipe blade are different from each other,
The first wipe blade wipes the nozzle surface and the surface of the nozzle guard, and the second wipe blade wipes the surface of the nozzle guard without wiping the nozzle surface. inkjet printer.   A liquid tank containing a cleaning liquid for cleaning the wipe blade is disposed at a lower part of the wipe blade, a porous resin base is disposed in the liquid tank, the base is immersed in the cleaning liquid, and the wipe blade The inkjet printer according to claim 1, wherein the deposit attached to the wipe blade is removed when the tip moves and the tip contacts the table.   The inkjet printer according to claim 1 or 2, wherein the relative position of the inkjet head and the wipe blade is moved by moving the carriage without changing the position of the wipe blade.   The said 1st wipe blade is divided into the said 3 part so that it may not contact each other by the U-shaped groove | channel from the said front-end | tip to a base end, The any one of the Claims 1-3 characterized by the above-mentioned. 2. An ink jet printer according to item 1.   The wipe blade has a third wipe blade, and the third wipe blade has a width wider than the width of the nozzle guard, and has a tip divided into three parts. Is a portion for wiping only the surface of the nozzle guard, and a central portion of the three portions is a portion for wiping the surface of the nozzle guard and the nozzle surface, and when wiping the inkjet head, 5. The ink jet printer according to claim 1, wherein the third wipe blade wipes the ink jet head following the first wipe blade. 6.

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