JP2008036953A - Inkjet recording device - Google Patents

Abstract

Provided is an ink jet recording apparatus capable of reducing the frequency of blade replacement by suppressing uneven wear of the blade and appropriately cleaning the nozzle surface without replacing the blade even when the blade is unevenly worn. To do.
An inkjet recording apparatus includes an inkjet head, a cap member, a blade, a second moving mechanism, and a control unit. The ink jet head 20 includes a head portion having a nozzle surface 25A for ejecting ink and a frame body having a frame body surface 22A disposed around the nozzle surface 25A. The cap member selectively seals the nozzle surface 25A and closely contacts only the frame surface 22A when the nozzle surface 25A is sealed. The blade 31 moves in the arrow X direction while contacting the nozzle surface 25A. The first moving mechanism 32 moves the blade 31 in the arrow Y direction. The control unit drives the first moving mechanism 32 at a predetermined timing.
[Selection] Figure 1

Description

  The present invention relates to an ink jet recording apparatus provided with a blade for cleaning a nozzle surface for discharging a liquid.

  The ink jet recording apparatus ejects minute liquid droplets from nozzle holes opened on the nozzle surface of an ink jet head. An ink jet recording apparatus is required to have high landing accuracy with respect to a droplet discharge target. If droplets or dust adheres to the nozzle surface, the droplet ejection accuracy decreases. In general, the nozzle surface is subjected to a liquid repelling treatment so that droplets and the like are less likely to adhere to the nozzle surface. Some inkjet recording apparatuses include a blade that removes droplets and dust from the nozzle surface by performing a cleaning operation that moves while contacting the nozzle surface (see, for example, Patent Documents 1 and 2). .)

Furthermore, there is an ink jet recording apparatus provided with a cap member that seals the nozzle surface to suppress drying of the nozzle surface and suppress clogging of the nozzle holes. However, when the cap member is in close contact with the nozzle surface, the liquid repellency of the nozzle surface is likely to deteriorate, and the nozzle surface is likely to be damaged such as scratches. Therefore, it is conceivable to arrange the frame surface around the nozzle surface and seal the nozzle surface by bringing the cap member into close contact with only the frame surface.
JP 2004-291619 A JP 2004-291364 A

  However, when an inkjet head is configured with a plurality of members including a head portion having a nozzle surface and a frame body having a frame body surface, a step is generated between the nozzle surface and the frame body surface, or a convex portion is present on the frame body surface. Sometimes.

  If there are steps or protrusions, when the cleaning operation is repeated, the edge of the blade wears unevenly, and deposits remain on the nozzle surface in a streak-like manner, resulting in a reduction in blade cleaning ability. If the nozzle surface is not properly cleaned, the landing accuracy of the liquid droplets discharged from the nozzle holes is lowered. If the blade is replaced each time the blade is worn, the recording efficiency and cost of the ink jet recording apparatus are lowered.

  An object of the present invention is to reduce the frequency of blade replacement by suppressing uneven wear of the blade, and properly clean the nozzle surface by the blade without replacing the blade even when the blade is unevenly worn. An object of the present invention is to provide an ink jet recording apparatus capable of performing the above.

  The ink jet recording apparatus of the present invention is configured as follows in order to solve the above-described problems.

  (1) An inkjet recording apparatus of the present invention includes an inkjet head, a cap member, a blade, a moving mechanism, and a control unit. The ink jet head includes a head portion having a nozzle surface for discharging a liquid and a frame body having a frame surface disposed around the nozzle surface. The cap member is a cap member that selectively seals the nozzle surface, and adheres only to the frame surface when the nozzle surface is sealed. The blade performs a cleaning operation that moves relative to the inkjet head in a direction along the first axis included in the nozzle surface while contacting the nozzle surface. The moving mechanism moves the blade relative to the inkjet head in a direction included in the nozzle surface and along a second axis different from the first axis. The control unit drives the moving mechanism at a predetermined timing.

  In this configuration, the frame body surface is disposed around the nozzle surface, and the cap member is in close contact with only the frame body surface, so that the nozzle surface during non-ejection without discharging liquid is sealed, and drying of the nozzle surface is suppressed. The nozzle surface is generally subjected to a liquid repellent treatment, but since the cap member does not contact the nozzle surface, deterioration and damage of the liquid repellent property of the nozzle surface are prevented.

  In addition, when the inkjet head is composed of a plurality of members including a head portion and a frame, and there is a step between the nozzle surface and the frame surface, deposits such as liquid remain on the step when the blade performs a cleaning operation. Cheap. The attached matter dries and solidifies, and the blade performs a cleaning operation on it, so that even when the blade is worn unevenly, the blade is not cleaned at a predetermined timing such as when the blade cleaning operation reaches a predetermined number of times. Move in a direction along two axes.

  Furthermore, even when the blade is unevenly worn due to the level difference between the nozzle surface and the frame surface, the blade moves in the direction along the second axis at a predetermined timing such as when the blade cleaning operation reaches a predetermined number of times. To do.

  (2) The ink jet recording apparatus of the present invention can further include a sealing portion that seals the gap between the head portion and the frame body and makes the nozzle surface and the frame surface continuous.

  In this configuration, since the gap between the head portion and the frame is sealed, the sealing performance of the nozzle surface by the cap member is improved. Further, since the nozzle surface and the frame surface are continuous, the blade moves while abutting continuously without being separated from the nozzle surface and the frame surface.

  (3) The linear expansion coefficient of the sealing portion of the ink jet recording apparatus of the present invention can be approximated to the linear expansion coefficients of the head portion and the frame.

  In this configuration, for example, the sealing part includes a linear expansion coefficient adjusting agent, so that the linear expansion coefficient of the sealing part approximates the linear expansion coefficient of the head part and the linear expansion coefficient of the frame.

  (4) In the ink jet recording apparatus of the present invention, the outer edge portion of the frame body surface on which the blade comes in contact with and separates in the direction along the first axis may have a curved shape.

  In this configuration, since the cap member is in close contact with the frame surface and liquid may adhere to the frame surface, it is desirable to clean the frame surface in addition to the nozzle surface. Since the frame surface is disposed around the cap member, when the blade moves in the direction along the first axis, the blade passes in the order of the frame surface, the nozzle surface, and the frame surface. That is, the blade contacts the outer edge portion in the direction along the first axis of the frame surface at the beginning and the end.

  (5) The ink jet recording apparatus of the present invention may be configured such that one member of the ink jet head and the blade is movable in both directions along the first axis and along the second axis.

  In this configuration, the member that is movable in the direction along the first axis among the inkjet head and the blade is configured to be movable in the direction along the second axis.

  (6) The cleaning operation of the ink jet recording apparatus of the present invention can include relative movement of the blade in both directions along the first axis with respect to the ink jet head.

  Since the blade abuts against the nozzle surface while curving the tip portion upstream in the movement direction, the downstream edge of the blade tip portion wears. In this configuration, since the blade moves relative to the inkjet head in both directions along the first axis, the edges on both sides of the tip of the blade are evenly worn in the direction along the first axis.

  In general, when the blade moves in the direction along the first axis, the downstream edge receives more damage in the moving direction of the blade than the upstream edge of the nozzle hole opening in the nozzle surface. . In this configuration, since the blade moves relative to the inkjet head in both directions along the first axis, damage to the edges on both sides of the nozzle hole in the direction along the first axis is equalized.

  Further, in general, when the blade moves in the direction along the first axis, in the moving direction of the blade, liquid or the like is present on the downstream edge as compared to the upstream edge of the nozzle hole opening in the nozzle surface. The deposits are likely to remain. However, in this configuration, since the blade moves relatively in both directions along the first axis with respect to the inkjet head, the deposits remaining when the blade moves in one direction are moved when the blade moves in the opposite direction. Removed.

  (7) In the ink jet recording apparatus of the present invention, at least the tip of the blade that contacts the nozzle surface can be made of perfluorofluororubber.

  Blades with nitrile rubber, urethane rubber or general fluororubber used at the tip will come into contact with liquids containing chemicals such as organic polar solvents such as ketones, esters, ethers, furans and ammonia, acids and alkalis. Since the part may be dissolved, swelled or deteriorated, it is not suitable for cleaning a liquid containing a chemical as described above.

  However, in the configuration of the present invention, a blade having at least a tip portion made of perfluorofluororubber is used. Perfluoro fluororubber is composed of a main chain portion made of TFE (tetrafluoroethylene), a branched portion made of PMVE (perfluoromethyl vinyl ether), and a cross-linked portion, and is completely fluorinated to produce Teflon (registered trademark) and Since it has a very similar structure, it has excellent liquid resistance against liquids containing the above-mentioned chemicals.

  In addition, perfluoro fluororubber has very little elution of contaminants such as gas and metal from the inside. Furthermore, the proper use temperature of perfluoro fluororubber is set to -20 ° C to + 220 ° C, and the range is wider than general fluororubber.

  According to the present invention, the following effects can be obtained.

  (1) Since the cap member does not contact the nozzle surface, it is possible to prevent deterioration and damage of the liquid repellency of the nozzle surface. For this reason, the cleaning effect of the nozzle surface by the blade can be maintained high.

  Further, by moving the blade in the direction along the second axis relative to the ink jet head, the step between the nozzle surface and the frame surface and the position of the blade contacting the deposit can be changed. For this reason, the progress speed of wear can be made uniform at each position of the blade. That is, uneven wear of the blade can be suppressed. Therefore, the replacement frequency of the blade can be reduced.

  Furthermore, even when the blade is worn unevenly due to a step between the nozzle surface and the frame surface or due to deposits remaining on the step portion, the blade moves relative to the inkjet head in the direction along the second axis. By performing the cleaning operation in this manner, the entire nozzle surface and frame surface can be appropriately cleaned.

  (2) By sealing the gap between the head part and the frame, the sealing performance of the nozzle surface by the cap member can be improved, so by making a negative pressure between the nozzle surface and the cap member, Air bubbles and dust can be reliably sucked from the inside of the nozzle hole opened in the nozzle surface. Therefore, the landing accuracy of the liquid can be increased.

  Moreover, the liquid can be drawn out from the nozzle hole by applying a negative pressure between the nozzle surface and the cap member. This liquid functions as a lubricant between the blade and the nozzle surface during the cleaning operation. For this reason, the nozzle surface can be prevented from being damaged by the blade during the cleaning operation.

  Furthermore, the nozzle surface and the frame surface can be continuously cleaned by making the nozzle surface and the frame surface continuous. Therefore, the nozzle surface can be appropriately cleaned by the blade so that no liquid or the like remains between the nozzle surface and the frame surface.

  In addition, since uneven wear of the blade due to the step between the nozzle surface and the frame surface can be suppressed, it is possible to suppress a decrease in landing accuracy due to wiping off deposits and to reduce the frequency of blade replacement. .

  (3) By approximating the linear expansion coefficient of the sealing part to the linear expansion coefficient of the head part and the linear expansion coefficient of the frame body, when the head part and the frame body are thermally expanded and contracted by returning to room temperature However, peeling with a head part and a frame, and a sealing part can be suppressed.

  (4) Since the outer edge portion of the frame body surface where the blade contacts and separates in the direction along the first axis is a curved surface, the blade and the outer edge portion are squared or compared to the case where the outer edge portion has irregularities such as burrs. The frictional force with the frame surface can be reduced, and blade wear can be suppressed.

  (5) Of the inkjet head and the blade, the member that is movable in the direction along the first axis is configured to be movable in the direction along the second axis, so that the direction along the first axis is It is not necessary to provide a drive mechanism on the member different from the movable member. For this reason, compared with the case where both are provided with a drive mechanism, a mechanism for moving the blade relative to the ink-jet head can be easily configured, and the apparatus can be reduced in size and cost.

  (6) Since the edges on both sides of the tip of the blade are evenly worn in the direction along the first axis, the degree of wear of the edge on one side of the tip of the blade can be halved. For this reason, the replacement frequency of the blade can be halved.

  Also, since the edges on both sides of the nozzle hole in the direction along the first axis are evenly damaged, the damage on one edge is halved compared to the case where only one edge of the nozzle hole is damaged. In addition, since the damage received by the edges on both sides of the nozzle hole is not biased, it is possible to suppress a decrease in liquid landing accuracy.

  Furthermore, since the blade moves relative to the inkjet head in both directions along the first axis, it is possible to suppress the deposits from remaining on the edge of the nozzle hole.

  (7) Since it has excellent liquid resistance against various liquids, it can be cleaned without changing the quality of various liquids. For this reason, it is possible to reduce the frequency of blade replacement for various types of liquids. Moreover, since the elution of contaminants is small, the nozzle surface can be appropriately cleaned. Furthermore, since the temperature range suitable for use is wide, the durability of the inkjet head against heating is excellent, and the frequency of blade replacement can be further reduced.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a partial configuration of an ink jet recording apparatus 10 according to an embodiment of the present invention as viewed obliquely from below. FIG. 2 is a partially exploded perspective view showing the configuration of the head unit. FIG. 3 is a diagram illustrating the configuration of the inkjet head 20.

  The ink jet recording apparatus 10 includes an ink jet head 20 and a cleaning device 30. The inkjet recording apparatus 10 is applied to an image forming apparatus, a production apparatus that manufactures a color filter substrate for liquid crystal, or a production apparatus that performs wiring drawing.

  The inkjet head 20 has a head portion 21 and a frame body 22. The head unit 21 includes a piezoelectric substrate 23, a cover member 24, and a nozzle plate 25. The piezoelectric substrate 23 includes a plurality of grooves that are polarized in the thickness direction and form the ink chamber 26. The cover member 24 is bonded to the upper surface of the piezoelectric substrate 23, so that the ink chamber 26 is configured by the groove portion and the cover member 24. The nozzle plate 25 is bonded to the piezoelectric substrate 23 and the front end surfaces of the cover member 24. The nozzle plate 25 includes nozzle holes 27 at positions corresponding to the ink chambers 26, and ink is ejected from the front end surface of the head portion 21 through the nozzle holes 27. Ink is an example of the liquid of the present invention.

  Although not shown, an electrode is formed on the inner wall of the ink chamber 26. The rear end of the electrode is filled with a conductive material. An external connection terminal is connected to the conductive material.

  The cover member 24 includes a groove portion that constitutes the common ink chamber 28. The common ink chamber 28 communicates with all the ink chambers 26. The ink is supplied from an ink tank (not shown) to the common ink chamber 28 and is supplied from the common ink chamber 28 to each ink chamber 26.

  When a voltage corresponding to print data is applied from the external connection terminal to the electrode through the conductive material, the side wall of the ink chamber 26 is deformed so as to protrude inward, the ink in the ink chamber 26 is pressurized, and the nozzle hole 27 ejects ink.

  Ink supply to the ink chamber 26 is performed by applying a voltage opposite to that during pressurization to the electrodes. That is, when a voltage opposite to that applied during pressurization is applied to the electrode, the side wall of the ink chamber 26 is deformed so as to protrude outward, and the inside of the ink chamber 26 becomes negative pressure. As a result, ink flows from the common ink chamber 28 into the ink chamber 26.

  As shown in FIG. 3, the frame body 22 has a through hole at the center of a predetermined frame body surface 22 </ b> A, and the head portion 21 is disposed in the through hole. Thus, the frame surface 22A is arranged around the nozzle surface 25A of the nozzle plate 25. The nozzle surface 25A is liquid-repellent.

  When the ink jet head 20 does not eject ink, the cap member 29 is in close contact with only the frame surface 22A while facing the nozzle surface 25A and holding a predetermined space between the cap surface 29 and the nozzle surface 25A. When the cap member 29 is in close contact with the frame surface 22A, the nozzle surface 25A is sealed, and ink drying is suppressed. The cap member 29 is spaced apart from the frame surface 22A and opens the nozzle surface 25A when the ink jet head 20 discharges ink.

  Since the cap member 29 does not come into contact with the nozzle surface 25A, deterioration of the liquid repellency of the nozzle surface 25A and damage such as damage to the nozzle surface 25A are prevented. For this reason, the cleaning effect of the nozzle surface 25A by the blade 31 is maintained high.

  The ink jet head 20 is moved to a desired position by a driving mechanism (not shown) and ejects ink droplets. The drive mechanism causes the inkjet head 20 to reciprocate in the direction of arrow X, which is the main scanning direction (corresponding to the direction along the first axis of the present invention). The plurality of nozzle holes 27 are formed in a row on the nozzle surface 25 along an arrow Y direction (corresponding to a direction along the second axis of the present invention) which is a direction orthogonal to the arrow X direction.

  The cleaning device 30 includes a blade 31, a first moving mechanism 32, and a second moving mechanism 33, and cleans deposits such as ink adhering to the nozzle surface 25A and the frame surface 22A of the inkjet head 20 by wiping.

  The blade 31 is detachably mounted on the blade support portion 34, and performs a cleaning operation of moving in the arrow X direction while contacting the nozzle surface 25A and the frame surface 22A. Thereby, the adhering matter adhering to the nozzle surface 25A and the frame surface 22A is removed. The blade 31 is formed in such a size that both end portions in the arrow Y direction protrude by several mm outward from the inkjet head 20.

  The blade 31 is made of perfluorofluororubber which is an elastic member. As shown in FIG. 4, the perfluoro fluororubber is composed of a main chain portion 71 made of TFE (tetrafluoroethylene), a branched portion 72 made of PMVE (perfluoromethyl vinyl ether), and a bridging portion 73, and is completely fluorine. And a structure very similar to Teflon (registered trademark).

  For this reason, the blade 31 is not liable to be dissolved, swollen or altered even when it comes into contact with a liquid containing an organic polar solvent such as ketone, ester, ether, furan or ammonia, or a chemical such as acid or alkali. It is excellent in liquid resistance against various liquids and can be cleaned without changing the quality of various liquids. Accordingly, it is possible to reduce the frequency of blade replacement for various types of liquids.

  Moreover, since perfluoro fluororubber has very little elution of contaminants such as gas and metal from the inside, the nozzle surface can be appropriately cleaned. Furthermore, the pertinent use temperature of perfluoro fluororubber is set to −20 ° C. to + 220 ° C., and since the range is wider than that of general fluororubber, the durability of the inkjet head 20 against heating is excellent. The replacement frequency is further reduced.

  The blade 31 can also be formed of perfluorofluororubber only at the tip portion that contacts the nozzle surface 25A and the frame surface 22A, and can be formed of other materials other than the tip portion.

  The blade support part 34 is supported by the first moving mechanism 32. The first moving mechanism 32 is supported by the second moving mechanism 33. The first moving mechanism 32 moves the blade 31 supported by the blade support portion 34 in the arrow Y direction. The second moving mechanism 33 is fixed to an apparatus main body (not shown) of the ink jet recording apparatus 10 and moves the blade 31 in the arrow X direction via the first moving mechanism 32 and the blade support portion 34.

  As shown in FIG. 5, the first moving mechanism 32 includes a servo motor 321, a lead screw 322, a slide table 323, and the like. The second moving mechanism 33 includes a servo motor 331, a lead screw 332, a slide table 333, and the like. The servo motors 321 and 331 rotate the lead screws 322 and 332.

  The drive states of the servo motors 321 and 331 are controlled by a control unit 40 connected via drivers 41 and 42. The lead screws 322 and 332 penetrate the slide tables 323 and 333, and move the slide tables 323 and 333 in the arrow Y direction and the arrow X direction by rotation. The slide table 323 supports the blade support portion 34. The slide table 333 supports the first moving mechanism 32.

  FIGS. 6A to 6C are perspective views showing a part of the procedure for cleaning the nozzle surface 25A and the frame surface 22A. As shown in FIG. 6A, in the state where the inkjet head 20 has finished the ink ejection operation and moved to the standby position, the blade 31 is moved to the nozzle as shown in the order of FIG. 6B and FIG. 6C. While being in contact with the surface 25A and the frame surface 22A, it is moved in the arrow X1 direction, which is one direction along the arrow X direction. As a result, when there is no abnormality such as uneven wear at the tip of the blade 31, the adhering matter 51 such as ink and dust attached to the nozzle surface 25A and the frame surface 22A is removed.

  As shown in FIG. 7, when there is a convex portion 52 on the nozzle surface 25A or the frame surface 22A, or when there is a step between the nozzle surface 25A and the frame surface 22A, the cleaning operation is performed many times (for example, about 300 times). ) By repeating, as shown in FIG. 8A, a concave portion 311 may be formed at the tip of the blade 31 in some cases.

  If there is a recess 311 at the tip of the blade 31, deposits may remain in a streak pattern in the direction along the arrow X <b> 1. For this reason, after moving the blade 31 to the start position of the cleaning operation shown in FIG. 6A, the blade 31 is moved in the direction of the arrow Y1, which is one direction along the direction of the arrow Y. Next, as shown in FIGS. 8B and 8C, the blade is moved in the arrow X1 direction.

  Thereby, the deposit 51 remaining on the nozzle surface 25A and the frame surface 22A is removed. This is because the relative position of the blade 31 with respect to the nozzle surface 25A and the frame surface 22A has been changed in the direction of the arrow Y1, and therefore the blade at a position different from the recess 311 at the position where the deposits on the nozzle surface 25A and the frame surface 22A remained. This is because 31 moved while abutting.

  The movement of the blade 31 in the arrow Y direction is performed every time the cleaning operation by moving the blade 31 in the arrow X1 direction is performed a predetermined number of times.

  By moving the blade 31 in the arrow Y direction relative to the inkjet head 20, the position of the blade 31 that contacts the deposit 51 and the step between the nozzle surface 25A and the frame surface 22A can be changed. For this reason, the progress speed of wear can be made uniform at each position of the blade 31. That is, uneven wear of the blade 31 can be suppressed. Therefore, the replacement frequency of the blade 31 can be reduced.

  Further, even when the blade 31 is unevenly worn by the step between the nozzle surface 25A and the frame surface 22A or by the deposit 51 remaining on the step portion, the blade 31 is moved relative to the inkjet head 20 by the arrow Y. By moving in the direction and performing the cleaning operation, the entire nozzle surface 25A and frame body surface 22A can be appropriately cleaned.

  Furthermore, since the member of the inkjet head 20 and the blade 31 that is configured to be movable in the arrow X direction is also configured to be movable in the arrow Y direction, the member configured to be movable in the arrow X direction. It is not necessary to provide a drive mechanism for the member different from the above. Therefore, a mechanism for moving the blade 31 relative to the ink-jet head 20 can be simply configured as compared with the case where both are provided with a drive mechanism, and the ink-jet recording apparatus 10 can be reduced in size and cost. Can be planned.

  As shown in FIG. 9, during the cleaning operation, the blade 31 can be moved relative to the inkjet head 20 in both directions of the arrow X1 direction and the opposite direction, the arrow X2 direction.

  Since the blade 31 abuts the nozzle surface 25A while curving (elastically deforming) the tip portion in the upstream side in the movement direction, the edge 312 on the downstream side of the tip portion of the blade 31 is worn. For this reason, when the blade 31 moves in the arrow X1 direction, the downstream edge 312 in the arrow X1 direction wears, and when the blade 31 moves in the arrow X2 direction, the downstream edge 313 in the arrow X2 direction wears. In the inkjet recording apparatus 10, the blade 31 moves relative to the inkjet head 20 in both the arrow X1 direction and the arrow X2 direction, so that the edges 312 and 313 on both sides of the tip of the blade 31 in the arrow X direction are equal. Wear out. Therefore, the wear degree of the edge on one side of the tip of the blade 31 can be halved, and the replacement frequency of the blade 31 can be halved.

  In general, when the blade 31 moves in the direction of the arrow X1, the edge on the downstream side of the nozzle hole 27 receives more damage in the direction of the arrow X1 than the edge on the upstream side of the nozzle hole 27. In the ink jet recording apparatus 10, the blade 31 moves relative to the ink jet head 20 in both the directions of the arrow X1 and the arrow X2, so that the damage received by the edges on both sides of the nozzle hole 27 in the arrow X direction is equalized. Is done. For this reason, compared with the case where only one edge of the nozzle hole 27 is damaged, the damage on the one edge can be halved and the damage received on the both edges of the nozzle hole 27 is not biased. Therefore, it is possible to suppress a decrease in ink landing accuracy.

  Furthermore, as shown in FIG. 10, generally, when the blade moves in the direction of the arrow X1, in the direction of the arrow X1, the ink or the like is moved toward the downstream edge compared to the upstream edge of the nozzle hole 27. The deposit 51 tends to remain. However, in the inkjet recording apparatus 10, the blade 31 moves relative to the inkjet head 20 in both the arrow X1 direction and the arrow X2 direction, and therefore, deposits that remain when the blade 31 moves in the arrow X1 direction. 51 is removed when moving in the direction of the opposite arrow X2. In this manner, the blade 31 moves relative to the inkjet head 20 in both the directions of the arrow X1 and the arrow X2, so that the deposit 51 can be prevented from remaining on the edge of the nozzle hole 27.

  The edge of the blade 31 brought into contact with the nozzle surface 25A can be changed for each cleaning operation. For example, in one cleaning operation, the blade 31 can be moved only in the arrow X1 direction, and in the next cleaning operation, the blade 31 can be moved in the arrow X2 direction. When the blade 31 moves in the arrow X1 direction, the edge 312 contacts the nozzle surface 25A, and when the blade 31 moves in the arrow X2 direction, the edge 313 contacts the nozzle surface 25A.

  Further, the edge of the blade 31 to be brought into contact with the nozzle surface 25A can be changed every two or more predetermined cleaning operations. This makes it easy to control the driving of the blade 31.

  Further, the edge of the blade 31 to be brought into contact with the nozzle surface 25A can be changed within one cleaning operation. For example, in one cleaning operation, after the blade 31 is moved in the arrow X1 direction, the blade 31 can be further moved in the arrow X2 direction without rotating.

  Further, as shown in FIG. 11, the edge of the blade 31 to be brought into contact with the nozzle surface 25A is only one edge, and the blade 31 is relative to the inkjet head 20 in both directions of the arrow X1 direction and the arrow X2 direction. Can be moved. For example, after the blade 31 is moved in the arrow X1 direction while the edge 312 is in contact with the nozzle surface 25A, the blade 31 is moved so that the upstream surface and the downstream surface of the blade 31 are reversed in the arrow X1 direction. Then, the blade 31 can be moved in the direction of the arrow X2. According to this, even when an edge 313 other than the edge 312 on one side of the blade 31 cannot be brought into contact with the nozzle surface 25A in manufacturing the blade 31, the blade 31 is moved in the direction of the arrow X1 with respect to the inkjet head 20 and It can be moved relatively in both directions of the arrow X2.

  FIG. 12A is a perspective view showing the configuration of the inkjet head 20, and FIG. 12B is a perspective view showing the configuration of an inkjet head 20A according to another embodiment.

  As shown in FIG. 12A, when the outer edge portion of the frame surface 22A of the inkjet head 20 where the blade 31 contacts and separates in the arrow X direction is angular, a convex portion such as a burr is formed on the angular outer edge portion. Sometimes. For this reason, the recessed part 311 is formed in the part of the braid | blade 31 contact | abutted to the angular outer edge part, and there exists a possibility that the braid | blade 31 may wear out unevenly.

  On the other hand, as shown in FIG. 12B, the outer edge portion of the frame body surface 22A of the inkjet head 20 where the blade 31 contacts and separates in the direction of the arrow X is formed into a curved surface, so that the blade at the outer edge portion is formed. 31 wear is suppressed. Further, since the recovery speed of the elastic deformation of the blade 31 becomes gentle at the outer edge portion formed in the curved surface shape of the frame surface 22A, the adhering matter 51 such as ink at the outer edge portion on the downstream side in the moving direction of the blade 31. Residue is suppressed.

  FIG. 13 is a diagram illustrating a configuration of an inkjet head 20B according to another embodiment. The inkjet head 20B includes a head part 21, a frame body 22, and a sealing agent 61 (sealing part).

  The frame 22 has a through hole in the center of a predetermined frame surface 22A, and the head portion 21 is disposed in the through hole. A space between the head portion 21 and the frame body 22 is sealed with a sealant 61. The sealant 61 seals the gap between the head portion 21 and the frame body 22 and makes the nozzle surface 25A and the frame body surface 22A continuous.

  The sealing agent 61 is, for example, an adhesive, and includes a linear expansion coefficient adjusting agent that approximates the linear expansion coefficient to the linear expansion coefficients of the head portion 21 and the frame body 22. As the linear expansion coefficient adjusting agent, for example, spherical particles such as alumina, silica, and aluminum nitride are used. The type, particle size, concentration, and the like of the linear expansion coefficient adjusting agent to be used can be appropriately selected depending on the difference in the linear expansion coefficient between the adhesive to be used and the adherend.

  By including the linear expansion coefficient adjusting agent in the sealing agent 61, the linear expansion coefficient of the sealing agent 61 approximates the linear expansion coefficient of the head portion 21 and the linear expansion coefficient of the frame body 22. By approximating the linear expansion coefficient of the sealant 61 with the linear expansion coefficient of the head portion 21 and the linear expansion coefficient of the frame body 22, the head portion 21 and the frame body 22 contract when they thermally expand and return to room temperature. Even if it did, peeling with the head part 21 and the frame 22, and the sealing agent 61 is suppressed.

  The cap member 29 is in close contact with only the frame surface 22A when the inkjet head 20B does not eject ink.

  Since the gap between the head portion 21 and the frame body 22 is sealed with the sealant 61, the nozzle surface 25 </ b> A is reliably sealed with the cap member 29. For this reason, by setting the space between the nozzle surface 25A and the cap member 29 to a negative pressure, air bubbles and dust can be reliably sucked from the inside of the nozzle hole 27 opening in the nozzle surface 25A. Therefore, the landing accuracy of the liquid can be increased.

  Further, by setting a negative pressure between the nozzle surface 25A and the cap member 29, ink can be drawn out from the nozzle hole 25A. This ink functions as a lubricant between the blade 31 and the nozzle surface 25A during the cleaning operation. For this reason, it is possible to prevent the nozzle surface 25A and the frame body surface 22A from being damaged by the blade 31 during the cleaning operation.

  Further, since the nozzle surface 25A and the frame surface 22A are continuous, the blade 31 moves while continuously contacting the nozzle surface 25A and the frame surface 22A without being separated. Therefore, the surface of the inkjet head 20B including the nozzle surface 25A and the frame body surface 22A can be appropriately cleaned by the blade 31 so that the deposit 51 such as ink does not remain between the nozzle surface 25A and the frame body surface 22A. .

  Furthermore, when the sealing agent 61 makes a business trip from the nozzle surface 25A and the frame surface 22A, or when the sealing agent 61 adheres to the nozzle surface 25A or the frame surface 22A, the sealing agent 61 becomes the nozzle surface 25A and the frame surface. There is a risk of forming a convex portion on the surface of the inkjet head 20B including 22A. However, in the inkjet recording apparatus 10, since the blade 31 also moves in the arrow Y direction relative to the inkjet head 20B, the surface of the inkjet head 20 including the nozzle surface 25A and the frame surface 22A is appropriately cleaned.

  Next, a first experiment on the ink jet recording apparatus 10 will be described. In this experiment, as shown in FIG. 13, an inkjet head 20 </ b> B having a head portion 21, a frame body 22, and a sealant 61 was used.

The sealing agent 61 is an epoxy-based adhesive, and the adhesive contains SiO ₂ particles having an average particle diameter of 20 μm as a linear expansion coefficient adjusting agent.

  The blade 31 is a molded product of perfluorofluororubber, 25 mm wide × 9 mm high, and 0.5 mm thick. The blade 31 was mounted on the blade support 34 so that the free length was 4 mm. The free length is the extension amount of the blade 31 from the blade support portion 34.

  The cleaning operation is performed under the condition that the overlap length of the blade 31 with respect to the surface of the inkjet head 20B including the nozzle surface 25A and the frame surface 22A is 0.6 mm, and the relative moving speed between the inkjet head 20B and the blade 31 is 2 mm / sec. It was. The overlap length is a value obtained by subtracting the distance between the surface of the inkjet head 20B including the nozzle surface 25A and the frame surface 22A and the blade support portion 34 from the free length of the blade 31.

  When the operation of performing the cleaning operation once after the suction of the nozzle hole 27 by the cap member 29 was repeated 300 times, as shown in FIG. 14, the deposit 51 remained in a streak shape.

  FIG. 15 is an enlarged view of the deposit 51 remaining in a streak shape. FIG. 16A is a diagram illustrating a worn state of the blade 31, and FIG. 16B is a diagram in which the blade 31 in a cleaning operation state in contact with the glass plate is observed through the glass plate.

  It can be confirmed that a recess 311 is formed on the edge of the blade 31 due to uneven wear of the blade 31.

FIG. 17B is an enlarged view of the recessed portion 311 of the blade 31 observed. When the line of the inkjet head 20B that was repeatedly wiped by the concave portion 311 of the blade 31 was confirmed, the SiO ₂ particles protruded from the nozzle surface 25A by 10 μm to form a convex portion.

  FIG. 18 shows the result of the evaluation of ink landing in this state. The vertical axis represents the ink landing position, and the horizontal axis represents the position of each of the plurality of nozzle holes 27. It can be seen that the landing position of the nozzle hole 27 where the deposit 51 remains in a streak is shifted in the direction of the streaks of the deposit 51.

  When the cleaning operation is performed with the blade 31 moved relative to the inkjet head 20B in the direction of the arrow Y by 1 mm, the streaky deposit 51 left unwiped is removed, and the landing position of the nozzle hole 27 is shifted. Recovered.

  Next, a second experiment for the ink jet recording apparatus 10 will be described.

  In this experiment, an experiment was performed under the same conditions as the first experiment, except that the inkjet head 20 having no sealant 61 shown in FIG. 3 was used.

  The used inkjet head 20 has a frame surface 22A disposed around the nozzle surface 25A, but does not have the sealant 61 between the nozzle surface 25A and the frame surface 22A.

  As in the first experiment, the cleaning operation was repeated 300 times. As in the first experiment, the deposit 51 remained in a streaky pattern on the nozzle surface 25A.

  When the blade 31 was observed, it was confirmed that the concave portion 311 was formed at the position of the blade 31 corresponding to the position where the streaky deposit 51 remained.

  As a result of checking the line of the inkjet head 20 that was repeatedly wiped by the concave portion 311 of the blade 31, there was a 5 μm abrasive grain protrusion on the frame surface 22A.

  When the cleaning operation was performed in a state where the blade 31 was moved relative to the inkjet head 20 by 1 mm in the arrow Y direction, the streaky deposit 51 left unwiped was removed.

  Next, a third experiment for the ink jet recording apparatus 10 will be described.

  In this experiment, using the same inkjet head 20B and blade 31 as in the first experiment, the experiment was performed under the same cleaning conditions as in the first experiment.

  However, each time the cleaning operation is performed once after the nozzle hole 29 is sucked by the cap member 29, the blade 31 is moved by 0.5 mm in the arrow Y direction relative to the inkjet head 20B. Then, the next 10 cleaning operations are performed. This was repeated 30 times as one set, and a total of 300 cleaning operations were performed.

  Unlike the case of the first experiment and the second experiment, after the cleaning was completed, the deposit 51 due to unwiping remained on the nozzle surface 25A did not remain, and the blade 31 did not show uneven wear. Further, the landing accuracy of the inkjet head 20B was not deteriorated.

  In the third experiment, an example in which the blade 31 is moved in the direction of the arrow Y with respect to the inkjet head 20B every time the cleaning operation is performed 10 times is shown. The result can be obtained.

  The blade 31 to be used, the nozzle surface 22A, the material of the linear expansion coefficient adjusting agent, the structure of the inkjet heads 20, 20A, 20B, the cleaning conditions such as the contact pressure of the blade 31 against the inkjet heads 20, 20A, 20B, and the inkjet The timing at which the blade 31 is moved relative to the inkjet heads 20, 20A, 20B can be selected as appropriate depending on the space of the recording apparatus 10.

  In the cleaning of the nozzle surface 25A and the frame surface 22A, the inkjet heads 20, 20A, 20B can be moved instead of moving the blade 31. In addition, both the blade 31 and the inkjet heads 20, 20A, 20B can be moved.

  Finally, the description of the above-described embodiment is to be considered in all respects as illustrative and not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

It is the perspective view seen from the slanting lower part which shows the one part structure of the inkjet recording device which concerns on embodiment of this invention. It is a partially exploded perspective view which shows the structure of a head part. It is a figure which shows the structure of an inkjet head. It is explanatory drawing which shows the structure of perfluoro fluororubber. It is a figure which shows the structure of the outline of a 1st moving mechanism and a 2nd moving mechanism. (A)-(C) are perspective views which show a part of procedure which cleans a nozzle surface and a frame surface. It is sectional drawing which shows the shape of an inkjet head. (A)-(C) are perspective views which show a part of procedure which cleans a nozzle surface and a frame surface. It is sectional drawing which shows an example of the movement aspect of the braid | blade at the time of cleaning operation | movement. It is sectional drawing which shows the deposit | attachment adhering to a nozzle hole periphery at the time of cleaning operation | movement. It is sectional drawing which shows the other example of the movement aspect of the braid | blade at the time of cleaning operation | movement. (A) is a perspective view which shows the structure of an inkjet head, (B) is a perspective view which shows the structure of the inkjet head which concerns on other embodiment. It is a figure which shows the structure of the inkjet head which concerns on other embodiment. It is a figure of the inkjet head which shows the cleaning result in 1st experiment. It is an enlarged view of the deposit | attachment which remained like the streaks. (A) is a figure which shows the abrasion state of a braid | blade, (B) is the figure which observed the braid | blade of the cleaning operation state contact | abutted to the glass plate through the glass plate. (A) is a figure which shows the abrasion state of a braid | blade, (B) is an enlarged view which observed the recessed part of the braid | blade. It is explanatory drawing which shows the result of ink landing evaluation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Inkjet recording device 20, 20A, 20B Inkjet head 21 Head part 22 Frame 22A Frame surface 25 Nozzle plate 25A Nozzle surface 27 Nozzle hole 29 Cap member 30 Cleaning device 31 Blade 311 Concave 312, 313 Edge 32 First moving mechanism (moving) mechanism)
33 Second moving mechanism 34 Blade support part 40 Control part 51 Deposited substance 52 Convex part

Claims (7)

An inkjet head including a head portion having a nozzle surface for discharging a liquid and a frame body having a frame surface disposed around the nozzle surface;
A cap member that selectively seals the nozzle surface, the cap member closely contacting only the frame surface when sealing the nozzle surface;
A blade that performs a cleaning operation that moves relative to the inkjet head in a direction along a first axis included in the nozzle surface while abutting the nozzle surface;
A moving mechanism that moves the blade relative to the inkjet head in a direction that is included in the nozzle surface and along a second axis that is different from the first axis;
An ink jet recording apparatus comprising: a control unit that drives the moving mechanism at a predetermined timing.   The inkjet recording apparatus according to claim 1, further comprising a sealing portion that seals a gap between the head portion and the frame body and makes the nozzle surface and the frame surface continuous.   The inkjet recording apparatus according to claim 2, wherein a linear expansion coefficient of the sealing portion approximates a linear expansion coefficient of the head portion and the frame.   4. The inkjet recording apparatus according to claim 1, wherein an outer edge portion of the surface of the frame body on which the blade comes in contact with and separates in a direction along the first axis has a curved surface shape.   5. The member according to claim 1, wherein one member of the inkjet head and the blade is movable in both a direction along the first axis and a direction along the second axis. The ink jet recording apparatus described.   6. The inkjet recording apparatus according to claim 1, wherein the cleaning operation includes a relative movement of the blade in both directions along the first axis with respect to the inkjet head.   The inkjet recording apparatus according to claim 1, wherein at least a tip portion of the blade that contacts the nozzle surface is made of perfluorofluororubber.

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