JP2009160735A - Inkjet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wipe recovery means that is optimum when a long-size head is used in an inkjet recording device. <P>SOLUTION: The inkjet recording device includes at least one recording head 1 for ejecting ink and forming images, and a wipe blade 22 corresponding to the recording head 1 for wiping the ink ejection surface of the recording head 1. As the wipe blade 22 is advanced diagonally with respect to the direction of alignment of ink ejection nozzles of the recording head 1, the ink ejection surface of the recording head 1 is cleaned. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus including a recovery (cleaning) device for a recording head used in the ink jet recording apparatus.

In an ink jet recording apparatus having a recording head having an ejection port forming surface in which a plurality of ejection ports for ejecting ink are formed on the recording surface of a recording medium, the recording head is arranged around the nozzles and ejection ports of the recording head during recording and standby. Adherence of thickened ink and dust and mixing into the liquid chamber of the recording head cause problems such as ejection failure and recording disturbance.

  In order to solve such a problem, the ink in the recording head is forcibly discharged, the ink circulation recovery for circulating the ink in the recording head for discharging bubbles and dust accumulated in the recording head, and the ink circulation This is achieved by wiping recovery (wiping cleaning) with a wipe blade that is a cleaning member using ink discharged by recovery, thickened ink originally attached to the discharge port forming surface, and an elastic body for removing dust and the like.

  The wipe blade is provided for each of the arranged recording heads. One wipe blade is provided for each recording head, that is, if there are six heads, six wipe blades are provided.

  There are various methods for wiping the wipe blade depending on the arrangement direction of the wipe blade and the moving direction of the wipe blade.

  For example, there is a horizontal wiping method in which a wiping surface of a wipe blade is arranged in accordance with the nozzle array arrangement direction provided in the recording head, and the recording head is wiped while moving the wipe blade in a direction perpendicular to the nozzle array arrangement direction.

  According to the above method, since the wiping ink by the wipe blade does not pass to each nozzle, the cleaning state for each nozzle is good. However, when the length of the recording head in the nozzle array direction becomes a long head, for example, 4 inches, the wipe blade also becomes longer according to the length in the nozzle array direction, so that a uniform pressing force is applied to the wipe blade. There is also a problem that the wiping performance is not stable because it becomes difficult to add and the contact resistance with the recording head becomes non-uniform.

  Therefore, as a wiping method suitable for ensuring the wiping performance of the long head, the wiping surface of the wiping blade is arranged at a right angle with respect to the nozzle row arrangement direction as disclosed in Patent Document 1, and the wiping blade is used as the nozzle. There is a vertical wiper method in which the recording head is wiped while moving in the arrangement direction.

As shown in FIG. 11, with the vertical wiper method, the recording head is cleaned while moving in the Y direction. Therefore, the wipe blade width can be effective when the width of the head is about the width of the head. Can be demonstrated. In other words, the entire length of the wipe blade is shorter than that used in the horizontal wipe method, so that a uniform pressing force can be applied to the wipe blade, uniform contact resistance with the recording head, and stabilization of the wipe performance. Can measure. Therefore, the wiping performance is more stable than the vertical wiping method.
JP-A-2-34348

In the vertical wiping method, since the wipe blade moves in the longitudinal direction of the recording head, a single wiping distance, that is, the sliding time of the recording head and the wiping blade is long, and there is an edge portion at the ejection port of the recording head, When performing the wiping operation, the wipe blade repeatedly contacts the edge portion of the discharge port. In addition, there is a minute step between the member in which the discharge port is formed and the member that holds the member in which the discharge port is formed. That is, the edge of the wipe blade and the discharge port. Further, the contact portion between the wipe blade and the minute step is intensively worn, and a part of the wipe blade such as a Z portion in FIG. 12 is lost.
That is, the problem to be solved by the present invention is that the wipe blade, which is a cleaning member in the above-described state, deteriorates in performance early due to repeated cleaning operations.

Therefore. At least one recording head that forms an image by discharging liquid onto a recording medium, an ejection port that ejects liquid arranged in the recording head, an ejection port forming surface that forms the ejection port, and the recording head In the inkjet recording apparatus having a plate-like cleaning member for wiping the discharge port and the discharge port forming surface,
The said cleaning member solves the said subject by moving to the orthogonal | vertical direction of the said nozzle arrangement direction with the movement to the said nozzle arrangement direction.

  By using the above configuration, it is intended to increase the number of times the cleaning member is repeatedly used, and it is possible to provide an optimum wiping and cleaning means particularly when a long head is used.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

[First embodiment]
<Inkjet recording apparatus configuration>
FIG. 1 is a schematic front view of an inkjet image forming apparatus (inkjet recording apparatus) to which the present invention is applied.

  The recording apparatus 100 includes six recording heads 1 in total, and the recording head 1 ejects liquid by a heater that is an electrothermal transducer incorporated therein, and each recording head is used when creating a full-color image. Ink is a liquid of different colors, and black, cyan, magenta, yellow, etc., as an example of color, and if higher image quality is required, light cyan (photocyan) and light magenta (photomagenta) are assigned to each ink tank (black ink tank). 28K, cyan ink tank 28C, magenta ink tank 28M, yellow ink tank 28Y, light cyan ink tank 28LC, and light magenta ink tank 28LM). In addition, as an example of the physical properties of the ink, a dye system or a pigment system may be used as appropriate.

  Alternatively, for the purpose of high-speed printing, all the recording heads 1 may be divided and printed by using the same color, for example, the black ink tank 28K, so that one image is divided and formed by the number of the recording heads 1 mounted.

  Incidentally, in this embodiment, an example in which six recording heads are mounted is given, but the number of recording heads 1 mounted is not limited, and a configuration in which four recording heads are mounted as an example may be used.

  As a configuration of the recording head 1, the ink foamed by the heater is discharged from an ejection port provided in the recording head 1. About 2,400 nozzles are arranged in series in the longitudinal direction of the recording head 1 on one surface of the recording head 1. The discharge port forming surface on which the discharge port is formed has a smooth surface so that ink droplets and dirt due to dust can be immediately wiped away. A nozzle (not shown) communicates with the ejection port, and a common ink chamber is provided in the nozzle, and ink is supplied to the nozzle.

  The recording medium 11 wound in a roll shape is conveyed under the recording head 1 by the conveying roller 26, and various inks are ejected from each recording head 1 at a predetermined timing to form an image.

  2 to 4 show the structure of the recording portion used in this embodiment. Although the recording head 1 is a recording head having a recording width of 4 inches, the recording width of the recording head is not particularly limited. However, in the configuration of the present embodiment, particularly for a long head having a recording width of more than 2 inches. It works effectively.

  In order to prevent ink non-ejection due to dust adhering to these recording heads 1 and ink thickening due to evaporation of water in the ink to be ejected, a recovery device 10 as a recovery means of the recording head 1 is provided to maintain stable ejection. ing. The recovery device 10 is roughly divided into a capping mechanism 15 having a function of capping the recording head 1 and a wiping mechanism 20 having a function of wiping the recording head 1.

The capping mechanism 15 and the wiping mechanism 20 are provided according to the number of recording heads 1 to be mounted. In this embodiment, the capping mechanism 15 and the wiping mechanism 20 include six sets of the capping mechanism 15 and the wiping mechanism 20.
The wipe mechanism 20 has a function of appropriately wiping off ink droplets remaining on the face surface, which is a portion where the ink discharge port of the recording head 1 is present, after mainly discharging ink from the recording head 1.

  The wipe blade 22 of the wipe mechanism 20 is a plate-like cleaning member that wipes off the ink on the face surface provided in the recording head 1. In this embodiment, urethane rubber is used, but resistance to the ink used is used. For example, silicon, butyl, styrene rubber, PP, PE, etc. are made into a fibrous form if it is a material that does not scratch the recording head 1 or cause chemical damage (chemical attack, etc.). It is also possible to use an absorbent member or the like formed in a thin plate shape.

As shown in FIG. 5, the blade holder 25 holds the wipe blade 22 on the one hand, and slide guides 28 are provided at both ends of the blade holder 25. Furthermore, a slide rail 29 is provided on the recovery rod 30 corresponding to the slide guide 28. The slide rail 29 has an angle with respect to the recording head 1. In this embodiment, the recording head 1 is inclined by 1 ° to 3 °. This angle is desirably set as a moving amount that does not interfere with the adjacent recording head 1 due to the movement of the wipe blade 22, but is practically up to about 10 ° in consideration of the installation space. However, the present invention is not limited to the angle.
In the present embodiment, the slide rail 29 is configured to move in one direction, but in addition to this, the form of FIG. 7 in which the direction of the slide rail is changed at the center of the traveling direction, or an arc drawing FIG. It may be a form like The same effect can be obtained if the portion in contact with the discharge port is always changed.

In this embodiment, the wipe blade 22 is configured such that the wipe blade 22 is phase-shifted with respect to the fixed head. However, the recording head 1 is relatively moved with respect to the fixed wipe blade 22 depending on the configuration of the apparatus. The same effect can be obtained even with a configuration that allows
<Wipe operation>
The capping mechanism 15 will be described with reference to FIGS. The capping mechanism 15 mainly receives ink discharged from the recording head 1 and holds the ink to transfer the ink held in the temporary cap 31 to the waste liquid tank as waste liquid, and capping the recording head 1. It has a function of moisturizing and protecting the ink discharge port of the recording head 1.

  The member cap 31 that is in direct contact with the discharge port of the recording head 1 has flexibility such as chlorinated butyl rubber and good adhesion as an example. Further, since it should not affect the recording head 1 such as being fixed to the recording head 1 in a state of being left in contact with the recording head, it is necessary to evaluate the compatibility between the recording head 1 and the ink in a timely manner.

  The cap 31 is in contact with the recording head 1 and has a receiving opening 32 for receiving ink, and a discharge opening 35 for discharging ink at the lower part of the cap 31. The discharge opening 35 is connected to a discharge tube 34 for relaying with an ink discharge pump 36. The discharge pump 36 applies a constant pressure. In the case of suction, a negative pressure may be applied to the cap 31. Therefore, any commonly used tube pump, diaphragm pump, or positive displacement pump may be used as the pump.

  The discharged ink is circulated to the sub tank 55 by the discharge pump 36. If a filter is provided in the middle of the sub tank 55, the ink use efficiency can be increased.

  A cap holder 33 for holding the cap 31 can be moved toward and away from the recording head 1 while holding the cap 31, and can move through a gap 38 of a passing opening provided in the recovery rod base 37. Is provided.

  In addition, the recording apparatus 10 includes an ink cartridge 28 for storing ink to be supplied to the recording head 1, a pump unit 50 for supplying and recovering ink to the recording head, a pressure pump 50 for supplying ink to the recording head 1, A sub tank 55 that temporarily stores ink, a head joint 60 that connects the recording head 1 and the sub tank 55, and the like are included.

Next, a wiping method of the recording apparatus to which the present invention is applied will be described.
At the beginning of the recovery operation, the capping mechanism 15 is brought into contact with the recording head 1 as shown in FIGS. Since the recording head 1 and the capping mechanism 15 need only accept the ink discharged from the recording head 1, a strict distance is not required.

After a predetermined ink is supplied to the recording head 1 by the pressurizing pump 50 and the ink is discharged from the nozzle that is an ejection port of the recording head 1, the operation of the pressurizing pump 50 is stopped to move the capping mechanism 15 from the recording head 1. Separate. The temporarily accumulated ink is temporarily stored in the cap 31, passes through the discharge opening 35 and the discharge tube 34, and is connected to the other end of the discharge tube 34 (in this embodiment, -0.4 kgf). The pump is discharged from the capping mechanism 15 by a pump of about / cm ² .
The ink discharged from the recording head 1 is temporarily accumulated in the cap 31, but the cap 31 has a capacity of about 10 cc, whereas the ink discharged from the recording head 1 is about 3 cc at a time. Thus, the ink does not overflow from the cap 31 due to the ink discharging operation. The discharged ink is circulated from the discharge pump 36 to the sub tank 55 through the recycle tube 41.

  On the other hand, as shown in FIG. 5, the wiping mechanism 20 starts wiping from the wiping start point, wipes in the direction in which the ejection ports provided in the recording head 1 are arranged, and simultaneously in a direction perpendicular to the direction in which the ejection ports are arranged. Moving. That is, the wipe is performed obliquely with respect to the head.

FIG. 6 shows the state after the operation, and the wipe mechanism 20 moves along the slide rail 29. However, as a driving method of the wipe mechanism 20, the wipe mechanism 20 is engaged with the blade holder 25 provided in the wipe mechanism 20 and recovered. The wiper is driven by a wipe drive guide 35 that crosses the table 30, a wipe drive rack 39 provided in the wipe drive guide 35, and a wipe drive gear 38 that contacts the wipe drive rack 39 and transmits the drive. The wipe drive rack 39 and the wipe drive gear 38 are rack-pinion type gears, and the wipe drive rack 39 performs a linear motion as the wipe drive gear 38 rotates.
Details of the blade holder 25 will be described with reference to FIG. The blade holder 25 is provided with a guide engaging portion 27 and can be rubbed on the wipe driving guide 35 in the width direction of the blade holder 25. Since the blade holder 25 can move in the width direction on the wipe driving guide, the slide along the slide rail 29 provided on the recovery rod 30 also slides when the wipe driving guide 35 moves in the longitudinal direction of the recording head 1. It is possible to move according to the shape of the rail 29.

  Through a series of these operations, the wipe blade 22 constantly changes in the contact portion with the recording head 1, so that a part of the wipe blade 22 is not lost, and the wipe performance can be maintained for a long time. When the wipe blade moves along the slide rail 29 along the slide rail 29 so that the contact portion between the wipe blade 22 and the recording head 1 always changes, the movement along the slide rail of FIGS. The movement changes in the middle of the direction of travel. When such a movement is performed, the deflection direction of the blade can be made equal to the left and right. Since the wipe blade is an elastic member, the resistance against the deflection of the wipe blade can be improved by adding such movement.

[Second Embodiment]
FIG. 10 is a top view showing the second embodiment. The wipe mechanism 120 is configured to have an angle with respect to the ejection port provided in the recording head 101. In this embodiment, it has an angle of 5 ° with respect to the ejection port provided in the recording head 101. The other configurations of the recording head 101, the recovery device 110, the wipe driving guide 135, the wipe driving rack 139, and the wipe driving gear 138 are the same as those in the first embodiment.
The relative angle between the recording head 101 and the wiping mechanism 120 is set by the wiping speed, the amount of penetration of the wiping blade 122 provided in the recording head 1 and the wiping mechanism (the overlapping distance of the recording head 101 and the wiping blade 122), The optimum value varies depending on the physical properties of the ink and the optimum angle at which the ink can be efficiently wiped off may be determined as appropriate.

  As an example, for ink having a high viscosity among the ink physical properties, a method is adopted in which the wipe mechanism 120 is set to have a relatively large angle to accelerate the flow of ink. Further, it is preferable to set a small angle in order to prevent the ink having a low viscosity from protruding from the wipe blade due to excessive flow.

With the above configuration, the wipe mechanism 120 is driven from the wipe start point to the wipe end point, and the ink adhering to the recording head 101 is wiped off.

Schematic front view of an ink jet printer showing a form of a first embodiment to which the present invention is applied The perspective view which shows the wipe mechanism of a present Example Simplified longitudinal sectional view showing the wiping mechanism of this embodiment The figure which shows the ink flow path of the inkjet printer of a present Example. The figure which shows before the wipe operation | movement of the wipe mechanism of a present Example The figure which shows after the wiping operation | movement of the wiping mechanism of a present Example The figure which changed the wipe direction of the wipe mechanism of a present Example The figure which changed the wipe direction of the wipe mechanism of a present Example The figure which shows the structure of the wipe function of a present Example The top view of the inkjet printer which shows the form of 2nd Example to which invention is applied A perspective view showing a wiping operation by a conventional vertical wiping method The figure which shows the defect state of the wipe blade by the conventional vertical wiping method

Explanation of symbols

1: Recording head 10: Recovery device 11: Recording medium 15: Capping mechanism 20: Wiping mechanism 22: Wipe blade 25: Blade holder 28: Slide guide 29: Slide rail 31: Cap 33: Cap holder 37: Recovery table 50 : Pressurizing pump unit 55: Sub tank 100: Recording device

Claims (5)

At least one recording head that forms an image by discharging liquid onto a recording medium, an ejection port that ejects liquid arranged in the recording head, an ejection port forming surface that forms the ejection port, and the recording head In the inkjet recording apparatus having a plate-like cleaning member for wiping the discharge port and the discharge port forming surface,
The inkjet recording apparatus, wherein the cleaning member moves in a direction perpendicular to the nozzle arrangement direction in accordance with movement of the discharge ports in the arrangement direction.     2. The inkjet recording apparatus according to claim 1, wherein the cleaning member moves in a fixed direction in a direction perpendicular to the nozzle arrangement direction along with the movement in the nozzle arrangement direction.   The inkjet recording apparatus according to claim 1, wherein the cleaning member is provided at a right angle to the nozzle arrangement direction.   4. The ink jet recording apparatus according to claim 1, wherein the cleaning member is provided with an angle with respect to the nozzle arrangement direction.   The inkjet recording apparatus according to claim 1, wherein the recording head is a long head.

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