JP6062824B2 - inkjet printer - Google Patents

Description

  The present invention relates to an inkjet printer.

  Printers equipped with an ink jet recording head are widely known. Ink jet recording heads sometimes cause ejection defects due to clogging of nozzles with foreign matter or thickened ink. In order not to cause such a problem, the recording head periodically cleans the nozzle surface and the inside of the nozzle. For example, the nozzle surface is wiped with a wiper in order to remove foreign matter adhering to the nozzle surface of the recording head. In addition, in order to remove thickened ink and foreign matters clogged in the nozzle, the cap is brought into close contact with the nozzle surface, the pressure in the cap is lowered, the ink is forcibly sucked out from the nozzle, and the clogging of the nozzle is eliminated. By performing such cleaning, ejection failure can be prevented.

  In addition, the ink ejected from the nozzles during printing reaches the recording medium, and in addition to the adhering ink, the mist-like splash that floats as a mist, or jumps up after reaching the recording medium and floats as a mist. There is something to do. Due to such ink, the entire surface of the nozzle is soiled and accumulated, causing discharge failure.

  The technique described in Japanese Patent Application Laid-Open No. 2005-238611 discloses a technique for cleaning not only the vicinity of the nozzle but also the entire surface of the nozzle. By cleaning the entire nozzle surface, it is possible to remove ink that is missed by the wiper or ink that adheres firmly to the nozzle surface. In this technique, cleaning is performed by using a cleaning unit including a plate-shaped support plate and a tape-shaped cleaning material, and bringing the cleaning material into contact with the nozzle surface. Also, with this technology, the cap is equipped with lifting means, a support plate is placed on the cap, a cleaning material coated with a cleaning solution is placed on the support plate, and the cleaning material is removed from the nozzle surface by raising the cap. It is in contact with and cleaned. In addition, in order to enhance the cleaning ability, the cleaning material is slid or moved up and down repeatedly to repeat the contact and separation of the cleaning material.

JP 2005-238611 A

  However, even if the nozzle surface is clean, ink or foreign matter may adhere to the cap with which the nozzle surface abuts. In such a case, problems such as recontamination of the nozzle surface and poor adhesion due to a gap between the nozzle surface and the cap occur. In addition to keeping the nozzle surface clean, it is necessary to prevent ink and foreign matter from adhering to the nozzle surface. Further, conventionally, the cap has been cleaned by wiping the portion including the contact surface with the nozzle surface with a nonwoven fabric or the like. However, since the tip of the cap has a flexible configuration so as to be in close contact with the nozzle surface, there is a problem that the tip is deformed and wiped off when wiping. If ink or a foreign substance adheres to the cap, poor adhesion and re-contamination of the nozzle surface occur, resulting in ejection failure.

  The present invention provides a cleaning method and an ink jet printer that simultaneously clean not only the nozzle surface of a recording head but also a cap, remove dirt on the nozzle surface, and prevent ejection failure.

  The inkjet printer of the present invention includes a plurality of nozzles at positions facing the recording medium, a plurality of recording heads that eject ink from the nozzles, and the recording head, and intersects the conveyance direction of the recording medium. And a carriage driving means for driving the carriage, and a recording head. The recording head is arranged corresponding to each of the recording heads, and the tip of the recording head is in contact with the nozzle surface on which the nozzle is arranged and deformed. And a cap that is in close contact with the nozzle surface and forms a sealed space, a lifting / lowering unit that moves a cap base on which the cap is disposed in a contact / separation direction with respect to the nozzle surface, the carriage driving unit and the lifting / lowering unit A first sheet placed on the cap in an ink jet printer comprising: A second sheet placed on the first sheet, the second sheet has a plurality of through holes, the cap base has a claw portion for hanging the through holes, and the claw The first sheet and the second sheet are fixed on the cap by hanging the through-hole on the part, and the elevating means is lifted to move the first sheet and the second sheet to the cap and the The cap is pressed by a recording head, and the tip portion of the cap including the portion in contact with the nozzle surface of the cap is wiped by the first sheet, and the entire surface of the nozzle surface is wiped by the second sheet.

  Not only the nozzle surface of the recording head but also the cap can be cleaned at the same time to remove contamination on the nozzle surface.

FIG. 1 is a diagram illustrating a cleaning unit that cleans the recording head. FIG. 2 is an explanatory diagram of the cleaning sheet. FIG. 3 is a schematic diagram of an ink jet printer. FIG. 4 is a block diagram of the ink jet printer. FIG. 5 is a flowchart for cleaning the recording head.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating a recording head cleaning unit.
The cleaning unit 1 for cleaning the recording head will be described. The cap 2 is in close contact with the nozzle surface of the recording head and sealed. The suction pump 6 is a pump for sucking the inside of the cap 2 and is driven by a pump motor (not shown). The suction pump 6 sucks ink from the nozzle by making the sealed space formed by the cap 2 and the nozzle surface of the recording head negative pressure. Can do. The cap 2 is attached to the cap base 9. The cap base 9 is provided with seven caps 2. The cap 2 is provided for the number of recording heads.

  The cap 2 can be brought into contact with and separated from the recording head by moving the cap base 9 up and down by converting the rotary motion into a vertical motion via a cam or the like by the lift motor 7. At this time, the pump motor and the elevating motor 7 of the cap base 9 may be combined. That is, the rotation direction in which the ink is sucked and the rotation in the direction in which the recording head of the cap base 9 is in close contact are matched, and the lifting operation is idled using a torque limiter. A train wheel may be designed so that the suction pump is not rotated using a one-way clutch in a direction in which the cap base 9 is separated from the recording head. In addition, contact control cams 8 are attached to the four corners of the cap base 9. The contact control cam 8 controls the contact position between the cap 2 and the recording head. That is, the abutment control cam 8 abuts on a carriage, which will be described later, and the deformation amount of the cap 2 can be controlled according to the distance between the rotation center of the abutment control cam 8 and the carriage. When the distance is short, the deformation is large, and when the distance is long, the deformation is small. Moreover, it is preventing that it deform | transforms too much.

  Two sheets, that is, the first sheet 3 and the second sheet 4 can be placed on the top of the cap 2. The first sheet 3 is a sheet mainly for cleaning the cap 2. It is placed on top of the cap 2 and a cleaning liquid is applied to the first sheet 3. Thereafter, the second sheet 4 is placed. At the four corners of the second sheet 4, through holes 10 that can be hooked on the claw portions 5 provided on the cap base 9 are provided. The through-hole 10 is arranged so that a part thereof is related to the convex portion provided at the end portion on the long side of the second sheet. The periphery of the through hole 10 of the second sheet is easily deformed and is easily hung on the claw portion 5.

  The through hole 10 is deformed and hung on the claw portion 5. The distance between the through holes 10 of the second sheet 4 is shorter than the distance between the claw portions 5. A claw portion 5 is provided at a position lower than the tip of the cap 2. Therefore, the second sheet 4 is stretched and hung on the claw portion 5. The second sheet 4 presses and fixes the first sheet 3 disposed on the cap 2 to the cap 2 side.

  The first sheet 3 is preferably a flexible porous member, for example, a synthetic resin sponge. It is preferable that the 1st sheet | seat 3 is mounted so that all the caps 2 may be covered, and it does not bend between the caps 2 with two or more. This is because if the second sheet is bent, wrinkles or the like may be formed on the second sheet placed thereon, and the second sheet may not contact the entire surface of the nozzle surface. The second sheet 4 is preferably made of a material softer than the nozzle surface, and is preferably a flexible synthetic resin cloth such as nylon or polyester. A thing which does not damage the nozzle surface when coming into contact with the nozzle surface and does not generate any fiber residue is preferable.

  The first sheet 3 is used in contact with the cap 2, and the second sheet 4 is used in contact with the nozzle surface of the recording head 2. The first sheet 3 preferably has higher rigidity than the second sheet 4. The cap 2 has a convex shape on the periphery, but the nozzle surface is substantially flat. Therefore, the cap 2 side is harder than the nozzle surface side to make it easy to keep a flat surface, and the sheet is easy to contact the entire surface of the nozzle surface. The first sheet 3 is preferably thicker than the second sheet 4. In addition to the above, a cleaning liquid can be easily included.

  FIG. 2 is an explanatory diagram of the cleaning sheet. A state after the recording head is cleaned by the second sheet 4 on the recording head side among the cleaning sheets is shown. The cleaning liquid applied to the first sheet 3 wets the second sheet 4. A range 11 wetted by the cleaning liquid is indicated by a dotted line. The range wetted with the cleaning liquid is a range including a range in contact with the nozzle surface of the recording head. Furthermore, the ink adhering to the nozzle surface and a part of the ink in the nozzle ooze out into the second sheet 4 by being brought into contact with the recording head by the elevating means. For example, the range 12 where ink has oozed out is indicated by a broken line, but the ink adhering to the nozzle surface of the recording head corresponding to this range 12 bleeds out and the second sheet 4 is removed. Dirty. That is, it is possible to clean the ink that wants to adhere to the nozzle surface. The first sheet 3 and the second sheet 4 are sandwiched between the cap 2 and the nozzle surface and left for a predetermined time. The thickened or hardened ink is melted and adhered to the first sheet 3 and the second sheet 4.

  By changing the contact position of the contact control cam 8, it is possible to make it contact strongly or weakly, thereby changing the deformation amount of the cleaning sheet. For example, when the dirt is severe, the contact pressure is increased, the deformation amount of the sheet is increased, and the sheet is strongly washed. That is, the contact control cam 8 is rotated to a position where the distance from the rotation center to the carriage is shortened and stopped. Further, when the distance from the rotation center of the contact control cam 8 to the carriage is increased and stopped, the contact pressure can be lowered, the deformation amount of the sheet can be reduced, and the sheet can be washed weakly.

  The recording head and the cap 2 have different stains, surface hardness, and the like, and it is more preferable to use different sheets than to use the same sheet. By using two different types of sheets, the first sheet 3 and the second sheet 4, the recording head and the cap 2 can be suitably cleaned at the same time.

  FIG. 3 is a schematic diagram of an ink jet printer. The ink jet printer 20 includes a platen 23. The platen 23 is a flat plate that supports a recording medium conveyed by a plurality of conveying rollers 24 arranged in the longitudinal direction of the inkjet printer 20 on a flat surface. Although not shown, there are a large number of holes on the surface, and the recording medium is adsorbed on the surface of the platen 23 by suction. A carriage 27 reciprocates along the platen 23. An ink jet recording head is mounted on the carriage 27 and ejects ink onto a recording medium supported by the platen 23. The recording medium is paper, resin film, or the like. The recording unit 21 includes a carriage 27 and a recording head mounted on the carriage 27. The carriage reciprocates in the direction intersecting the recording medium conveyance direction. For example, the directions are orthogonal.

The rail 26 is a linear rail arranged along the longitudinal direction of the inkjet printer 20. The carriage 27 moves along this rail 26. The carriage 27 is fixed to the belt 25. The belt 25 is driven by a drive motor 22. The belt 25 is an endless belt wound around pulleys disposed on both sides of the rail 26, and is driven by the drive motor 22 to move the carriage 27 along the rail 26. A linear scale (not shown) is arranged along the rail 26, and a sensor for detecting the scale of the scale is mounted on the carriage 27. The scale is detected by the sensor, and the position of the carriage 27 can be detected.
Since the position of the moving carriage 27 can be detected, ink can be ejected in accordance with the position, and a desired image can be recorded on the recording medium.

  The wipe unit 28 is a device that wipes the nozzle surface of the recording head mounted on the carriage 27 with a wiper. It is arranged on the side of the platen 23. The carriage 27 is moved onto the wipe unit 28, and the wiper is moved along the longitudinal direction of the recording head to wipe the nozzle surface. In this example, wipers corresponding to the number of recording heads are provided.

  FIG. 4 is a block diagram of the ink jet printer. The control unit 30 is a control unit that controls the overall operation of the inkjet printer 20. It operates according to a program stored in the ROM 32. The RAM 31 is a work memory of the control means 30, a memory that temporarily stores information, and a memory that stores predetermined values such as setting values. The ROM 31 is a non-volatile memory that stores values necessary for control such as initial values in addition to programs.

  The media transport unit 33 includes a transport roller 24 and is a unit that transports the recording medium. A recording medium is also called a medium. It is controlled by the control means 30. The recording medium is conveyed on the platen 23 every predetermined length and recorded by the recording head. The carriage transport unit 34 includes a drive motor 22, a belt 25, and a pulley, and the operation is controlled by the control unit 30. The carriage transport unit 34 reciprocates the carriage 27 along the rail 26.

  The print control unit 35 operates under the control of the control unit 30. The print control means 35 can drive the recording head 36 to eject ink. The print control unit 35 performs ejection driving of the recording head 36 according to the position of the carriage 27 acquired by a carriage position acquisition unit 37 described later, and discharges ink onto the recording medium to record an image. The carriage position acquisition unit 37 operates under the control of the control unit 30 and causes the control unit 30 to acquire the position of the carriage 27. The carriage position acquisition unit 37 includes a linear scale arranged along the rail 26 and a sensor for detecting the scale. The sensor reads the linear scale and calculates the position of the carriage 27. The control unit 30 acquires the position of the carriage 27 and moves the carriage 27 to a predetermined position such as on the wipe unit 28 or the cleaning unit 1. In addition, the control unit 30 performs control to eject ink according to the earned position. By arranging the recording head at a specific position of the carriage 27, the position of the recording head can be acquired by acquiring the position of the carriage 27, and ink ejection can be controlled according to the position.

  The elevating means 38 operates under the control of the control means 30. The elevating means 38 is means for elevating the cap 2. The elevating means 38 includes a contact control cam 8. The contact control cam 8 can be rotationally driven by a motor (not shown), and the rotational position of the contact control cam 8 is controlled by controlling the motor. The elevating means 38 includes the elevating motor 7 and drives the elevating motor 7 to elevate the cap base 9.

  The suction means 39 includes the suction pump 6 and operates under the control of the control means 30. By driving the suction pump 6, air, ink or the like can be sucked from the cap 2. Further, by sucking when the cap 2 is in close contact with the nozzle surface, the air pressure in the sealed space can be reduced and ink can be sucked from the nozzle.

  The wiping means 40 operates under the control of the control means 30 and wipes the recording head. The wiping means 40 includes a wipe unit 28. The wiping means 40 is controlled by the control means 30 such as the number of wiping of the recording head, the wiping speed, and the like. The image memory 41 is a memory that operates under the control of the control means 30 and stores image data to be recorded. For example, an image for one scan of the carriage 27 is stored in the image memory 41, data is acquired from the image data in accordance with the position of the carriage, and ink is ejected from the recording head. The external device IF 42 operates under the control of the control unit 30 and is an interface with the external device. The external device IF 42 is connected to a host computer, and the control unit 30 can acquire image data to be recorded, set values of the device, and the like from the external device. . The operation panel 43 operates under the control of the control means 30. The operation panel 43 displays input means by the operation of the operator, the state of the device by the LCD display device, an instruction to the operator, and the like.

  FIG. 5 is a flowchart of the recording head cleaning operation. It operates under the control of the control means 30. In this operation, the nozzle surface of the recording head and the cap 2 are cleaned.

  First, in step S1, the recording head is retracted from the cleaning unit 1. At this time, since it is preferable to remove extraneous deposits and the like in advance before cleaning, the nozzle surface is wiped by the wipe unit.

  Next, in step S <b> 2, the first sheet 3 is placed on the cap 2 of the cleaning unit 1. At this time, on the operation panel 43, an instruction for placing the first sheet 3 on the cap 2 is displayed to the operator, and an instruction for inputting whether the operation is completed is displayed. If there is no input for completion of the operation, the process does not proceed to the next process, and if there is no input after a predetermined time, for example, 1 minute, it is determined that some problem has occurred during cleaning, Stop error display and cleaning operation.

  Next, in step S <b> 3, a cleaning liquid is applied to the first sheet 3. At this time, the operation panel 43 displays an instruction to the operator to apply the cleaning liquid to the first sheet 3, and displays an instruction to input whether the operation is completed. If there is no input for completion of the operation, the process does not proceed to the next process, and if there is no input after a predetermined time, for example, 1 minute, it is determined that some problem has occurred during cleaning, Stop error display and cleaning operation.

Next, in step S <b> 4, the second sheet is placed on the first sheet 3. At this time, the operation panel 43 displays an instruction to the operator to place the second sheet on the first sheet 3, and displays an instruction to input whether the operation has been completed. . If there is no input for completion of the operation, the process does not proceed to the next process, and if there is no input after a predetermined time, for example, 1 minute, it is determined that some problem has occurred during cleaning, Stop error display and cleaning operation.
Next, in step S5, the carriage 27 is moved onto the cleaning unit 1.

  In step S6, the elevating means 38 is controlled to raise the cap base 9 so that the contact control cam 8 and the bottom surface of the carriage 27 are brought into contact. The cap 2, the first sheet 3, and the second sheet 4 are deformed. The cleaning liquid soaked in the first sheet 3 dissolves the ink that has adhered to the cap 2 and dried. In addition, the cleaning liquid that has soaked into the first sheet 3 also soaks into the second sheet 4, and dissolves the dried ink that adheres to the nozzle surface of the recording head. By pressing the entire surface of the nozzle surface with the second sheet 4 infiltrated with the cleaning liquid, it is possible to wipe off foreign matters such as ink that is firmly fixed. The tip of the cap 2 gradually comes into strong contact with the first sheet 3 and the second sheet 4 comes into strong contact with the nozzle surface gradually. When the tip portion of the cap 2 starts to deform, the first sheet 3 and the second sheet 4 also begin to deform. This deformation can also be rubbed. Then, it moves to a position where it does not deform. Due to the deformation, the cleaning liquid contained in the first sheet 3 leaks out, and the leaked cleaning liquid reaches the ink solidified matter or foreign matter and penetrates.

  Next, in step S7, the second sheet is kept in contact with the recording head for a predetermined time, for example, 3 minutes, for example, for 3 minutes, so that the ink attached to the recording head and the cap 2 is sufficiently contacted. Since the dirt on the tip of the cap 2 and the nozzle surface can be cleaned, the adhesion problem can be solved.

  Next, in step S8, the cap 2 is lowered by controlling the lifting means 38. Then, the first sheet 3 and the second sheet 4 are removed. The cap 2 and the ink on the nozzle surface adhere to the first sheet 3 and the second sheet 4, respectively, and the cleaning is completed.

  The cleaning liquid needs to have the ability to re-dissolve the pigment / dye component and resin component of the ink attached to the recording head and the cap portion, and is preferably composed mainly of the main solvent of the ink. In addition, the control means 30 measures the interval from the previous cleaning, and if there is a predetermined time, for example, one day or more, the control means 30 reduces the interval between the nozzle surface and the cap 2 and increases the contact pressure. You may do. The contact control cam 8 is rotated by the control means 30 to change the contact position. When the contact pressure increases, each part strongly hits the cleaning sheet, so that a large amount of the cleaning liquid oozes out and the contact pressure increases, thereby improving the cleaning power. Since the contact pressure can be controlled by the rotation of the contact control cam 8, there is no variation in the cleaning power, and the same cleaning power can always be obtained.

  Further, the elevating means 38 may be controlled so that the cap 2 is gradually raised, for example, stepwise, and the tip of the cap 2 may be slowly deformed. By doing so, the cleaning power can be increased by rubbing the tip of the cap 2 and the first sheet 3. Further, since it is performed slowly, it can be rubbed while dissolving the ink solidified by the cleaning liquid. Although the distance on the nozzle surface side is short, the second sheet 4 and the nozzle surface can be rubbed while dissolving the ink solidified by the cleaning liquid.

  The present invention can be used for an ink jet printer.

DESCRIPTION OF SYMBOLS 1 Cleaning unit 2 Cap 3 1st sheet 4 2nd sheet 5 Claw part 6 Suction pump 7 Lifting motor 8 Contact control cam 9 Cap base 10 Through-hole 20 Inkjet printer 23 Platen 24 Carrying roller 25 Belt 26 Rail 27 Carriage 28 Wipe unit

Claims (6)

A plurality of recording heads provided with a plurality of nozzles at positions facing the recording medium, and discharging ink from the nozzles;
A carriage mounted with the recording head and reciprocating in a direction intersecting with the conveyance direction of the recording medium;
Carriage driving means for driving the carriage;
A cap that is arranged corresponding to each of the recording heads, a tip that contacts and deforms the nozzle surface on which the nozzles of the recording head are arranged, and is in close contact with the nozzle surface to form a sealed space;
Elevating means for moving the cap base on which the cap is arranged in the contact / separation direction with respect to the nozzle surface;
Control means for controlling the carriage driving means and the elevating means;
In an inkjet printer comprising:
A first sheet placed on the cap; and a second sheet placed on the first sheet;
The second sheet has a plurality of through holes, the cap base has a claw portion that hangs the through hole, and the first sheet and the second sheet are attached by hanging the through hole on the claw portion. Fixed on the cap,
By raising the elevating means, the first sheet and the second sheet are pressed by the cap and the recording head, and the tip end portion of the cap including the portion contacting the nozzle surface of the cap is moved to the first. An ink jet printer, wherein the entire surface of the nozzle surface is wiped with the second sheet by a sheet.   The cap is juxtaposed in the movement direction of the carriage, the first sheet covers all of the tip portion of the cap, the first sheet has higher rigidity than the second sheet, and the first sheet The inkjet printer according to claim 1, wherein the ink jet printer does not bend between the caps when placed on a cap.   The inkjet printer according to claim 2, wherein the first sheet is a resin porous member, and the second sheet is a resin cloth.   The inkjet printer according to claim 3, wherein a cleaning agent is applied to the first sheet.   The inkjet printer according to claim 4, wherein the cleaning agent contains a main solvent of ink as a component. Two of the claw portions are provided on both sides of the cap in the moving direction of the carriage,
The second sheet has convex portions at the four corners of the second sheet and on the side surface of the second sheet on the recording medium conveyance direction, and the through hole is provided so as to be part of the convex portion. And
When the through hole corresponding to each of the claw portions is hung, the peripheral portion of the through hole is deformed to be larger than the portion facing the cap, and each through hole is hooked on the corresponding claw portion. The inkjet printer according to any one of claims 1 to 5, wherein the inkjet printer is provided.