JP2013031962A - Nozzle face cleaning device - Google Patents

Abstract

A nozzle surface cleaning device that cleans a nozzle surface in a non-contact manner without leaving a cleaning liquid on the nozzle surface.
A cleaning liquid holding surface 104 formed on a cleaning liquid holding plate 102 is disposed to face a nozzle surface 52 of a head 50. A cleaning liquid is supplied between the cleaning liquid holding surface 104 and the nozzle surface 52, and the cleaning liquid is held in a film shape between the cleaning liquid holding surface 104 and the nozzle surface 52. The head 50 is moved so that the entire surface of the nozzle surface 54 contacts the cleaning liquid on the cleaning liquid holding surface. At this time, the movement of the head 50 is controlled so that the cleaning liquid does not remain on the nozzle surface. Further, the cleaning liquid holding surface 104 is formed with higher wettability than the nozzle surface 52 so that the cleaning liquid is dragged to the cleaning liquid holding surface side.
[Selection] Figure 7

Description

  The present invention relates to a nozzle surface cleaning device, and more particularly to a technique for cleaning a nozzle surface of an inkjet head in a non-contact manner.

  In an ink jet recording apparatus that records an image by ejecting fine droplets from a nozzle, if there is dirt on the nozzle surface (the surface on which the nozzle is formed) of the head, an ejection failure or the like is induced. For this reason, in the ink jet recording apparatus, the nozzle surface is periodically cleaned.

  In Patent Document 1, as a method for cleaning the nozzle surface, the nozzle surface is wiped with a blade, the nozzle surface is cleaned, the nozzle surface is wiped with a cleaning roller made of a porous material, and remains on the nozzle surface. A method for removing liquid is described.

  Further, in Patent Document 2, after cleaning the nozzle surface by bringing the nozzle surface into contact with the cleaning liquid discharged from the slit in a band shape, air is sprayed onto the nozzle surface to remove the liquid remaining on the nozzle surface. A method is described.

  Patent Document 3 describes a method of cleaning a nozzle surface by forming droplets on a cleaning table and touching the nozzle surface.

JP 2007-50590 Gazette JP 2008-201021 Japanese Patent Laid-Open No. 11-58752

  However, the method of Patent Document 1 has a drawback in that the nozzle surface is easily damaged due to a configuration in which dirt is wiped off with a blade.

  On the other hand, since the method of Patent Document 2 cleans the nozzle surface in a non-contact manner, the nozzle surface is not damaged, but the ink inside the nozzle is dried and solidified by the air blown after cleaning. There is.

  Moreover, since the method of patent document 3 cleans a nozzle surface only with a droplet, for example, when a long head such as a line head is cleaned, dirt gradually dissolves into the droplet, and the entire nozzle surface is cleaned. Has the disadvantage of being difficult to clean. Further, depending on the surface tension of the cleaning liquid, there is a drawback that the cleaning liquid remains on the nozzle surface. The cleaning liquid remaining on the nozzle surface causes discharge failure and the like.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a nozzle surface cleaning device that cleans the nozzle surface in a non-contact manner without leaving a cleaning liquid on the nozzle surface.

  Means for solving the problems are as follows.

  [1] A first aspect is a nozzle surface cleaning apparatus for cleaning a nozzle surface of an inkjet head, having a cleaning liquid holding surface having higher wettability than the nozzle surface, the cleaning liquid holding surface facing the nozzle surface. A cleaning liquid holding member that is disposed in a manner to hold the cleaning liquid in a film shape between the cleaning liquid holding surface and the nozzle surface, and a cleaning liquid supply unit that supplies the cleaning liquid between the cleaning liquid holding surface and the nozzle surface And a moving means for relatively moving the cleaning liquid holding member and the inkjet head so that the cleaning liquid holding surface relatively moves along the nozzle surface, and the moving means is controlled, Movement control means for controlling relative movement of the cleaning liquid holding member and the inkjet head so that the cleaning liquid does not remain on the nozzle surface.

  In this aspect, the cleaning liquid is supplied between the cleaning liquid holding surface and the nozzle surface arranged so as to face the nozzle surface, and the cleaning liquid is held in a film shape between the cleaning liquid holding surface and the nozzle surface. Then, the nozzle surface is cleaned by relatively moving the cleaning liquid holding surface and the nozzle surface. At this time, the movement between the cleaning liquid holding surface and the nozzle surface is controlled so that the cleaning liquid does not remain on the nozzle surface. Since the cleaning liquid holding surface is formed with higher wettability than the nozzle surface, it is possible to effectively prevent the cleaning liquid from remaining on the nozzle surface. The movement control (movement speed control) is performed, for example, on the wettability (liquid repellency) of the nozzle surface and the cleaning liquid holding surface, the surface tension of the cleaning liquid, and the cleaning liquid formed between the cleaning liquid holding surface and the nozzle surface. This is performed in consideration of the film thickness, the degree of contamination, and the like.

  [2] In a second aspect according to the first aspect, the cleaning liquid holding member has a cleaning liquid supply hole in the cleaning liquid holding surface, and the cleaning liquid supply means is connected to the cleaning liquid holding surface from the cleaning liquid supply hole. The cleaning liquid is supplied between the nozzle surfaces.

  According to this aspect, the cleaning liquid is supplied between the cleaning liquid holding surface and the nozzle surface from the cleaning liquid supply hole formed in the cleaning liquid holding surface. As a result, the cleaning liquid can be efficiently supplied between the cleaning liquid holding surface and the nozzle surface, and a film of the cleaning liquid can be reliably formed between the cleaning liquid holding surface and the nozzle surface.

  [3] In a third aspect according to the second aspect, the cleaning liquid supply hole is formed on the upstream side in the relative movement direction of the cleaning liquid holding surface with respect to the nozzle surface.

  According to this aspect, the cleaning liquid supply hole is formed on the upstream side in the moving direction of the cleaning liquid holding surface relative to the nozzle surface. Thus, a cleaning liquid film can be efficiently formed between the cleaning liquid holding surface and the nozzle surface.

  [4] In a fourth aspect, in any one of the first to third aspects, the cleaning liquid supply unit is configured to be able to selectively supply different types of the cleaning liquid.

  According to this aspect, it is possible to selectively supply different types of cleaning liquid between the cleaning liquid holding surface and the nozzle surface. Thereby, for example, an appropriate cleaning liquid can be selected according to the degree of dirt and the nozzle surface can be cleaned.

  [5] A fifth aspect is the above fourth aspect, further comprising cleaning liquid supply control means for controlling supply of the cleaning liquid by the cleaning liquid supply means, wherein the movement control means includes the cleaning liquid holding surface and the nozzle surface. The cleaning liquid supply control means supplies the cleaning liquid between the cleaning liquid holding surface and the nozzle surface according to the number of cleanings. Switch.

  According to this aspect, the cleaning liquid holding surface and the nozzle surface are relatively moved a plurality of times to clean the nozzle surface a plurality of times. At this time, the type of cleaning liquid supplied between the cleaning liquid holding surface and the nozzle surface is switched according to the number of times of cleaning. Thereby, while being able to clean a nozzle surface more appropriately, remaining of a washing | cleaning liquid can be prevented more effectively. That is, for example, in the case of cleaning twice, the first cleaning can be performed using a cleaning liquid having a high cleaning ability, and the second cleaning can be performed using a cleaning liquid having a low cleaning capacity (for example, pure water). Further, for example, the first cleaning can be performed using a cleaning liquid having a low surface tension, and the second cleaning can be performed using a cleaning liquid having a high surface tension.

  [6] In a sixth aspect according to the fifth aspect, the cleaning liquid supply means is configured to be able to selectively supply the cleaning liquid having different surface tensions, and the cleaning liquid supply control means corresponds to the number of cleanings. Then, the cleaning liquid having a low surface tension is switched to the cleaning liquid having a high surface tension.

  According to this aspect, when cleaning a plurality of times, the cleaning is performed by switching from the cleaning liquid having a low surface tension to the cleaning liquid having a high surface tension according to the number of times of cleaning. For example, when cleaning twice, the first cleaning is performed using a cleaning liquid having a low surface tension, and the second cleaning is performed using a cleaning liquid having a high surface tension. At least last cleaning with a cleaning liquid having a high surface tension can effectively prevent the liquid from remaining on the nozzle surface.

  [7] In a seventh aspect according to any one of the first to sixth aspects, the cleaning liquid holding surface is slit in a region downstream of the cleaning liquid holding surface relative to the nozzle surface in the moving direction. A cleaning liquid recovery hole is formed.

  According to this aspect, the slit-shaped cleaning liquid recovery hole is formed in the cleaning liquid holding surface. As a result, the cleaning liquid can be captured effectively, and the cleaning liquid can be prevented from remaining on the nozzle surface.

  [8] In an eighth aspect according to the seventh aspect, the cleaning liquid recovery hole is formed in parallel at a plurality of locations along a relative movement direction of the cleaning liquid holding surface and the nozzle surface. The width is gradually reduced toward the downstream side in the relative movement direction.

  According to this aspect, the cleaning liquid recovery holes are formed in parallel at a plurality of locations along the relative movement direction of the cleaning liquid holding surface and the nozzle surface. In addition, each cleaning liquid recovery hole is formed so that the width gradually decreases toward the downstream side in the moving direction of the cleaning liquid holding surface relative to the nozzle surface. As a result, the cleaning liquid can be efficiently captured and the cleaning liquid can be effectively prevented from remaining on the nozzle surface.

  [9] A ninth aspect further includes cleaning liquid suction means for sucking the cleaning liquid from the cleaning liquid recovery hole in the seventh or eighth aspect.

  According to this aspect, the cleaning liquid is sucked from the cleaning liquid recovery hole. As a result, the cleaning liquid can be captured more efficiently, and the cleaning liquid can be effectively prevented from remaining on the nozzle surface. When the cleaning liquid is sucked from the cleaning liquid recovery hole in this way, ink is also sucked from the nozzles at the same time. Therefore, the inkjet head controls the back pressure to be negative so that ink inside the nozzle is not sucked out.

  [10] In a tenth aspect according to any one of the first to ninth aspects, the cleaning liquid holding surface has a downstream region in a moving direction relative to the nozzle surface toward a downstream side in the moving direction. It is formed by convergence.

  According to this aspect, the downstream region in the moving direction of the cleaning liquid holding surface is converged and formed. Accordingly, the cleaning liquid can be collected at the convergence point at the end of the nozzle surface, and the cleaning liquid can be efficiently removed from the nozzle surface.

  [11] In an eleventh aspect according to the tenth aspect, the cleaning liquid holding surface is formed to converge toward one side in the width direction.

  According to this aspect, the downstream region in the movement direction of the cleaning liquid holding surface is formed to converge toward one side in the width direction (direction perpendicular to the movement direction). In general, since the nozzle is formed at the center in the width direction of the nozzle surface, the cleaning liquid can be prevented from remaining at least in the region where the nozzle is formed by converging at one end in the width direction.

  According to the present invention, the nozzle surface can be cleaned in a non-contact manner without leaving the cleaning liquid on the nozzle surface.

Front view showing the configuration of the main part of the inkjet recording apparatus A plan view showing a configuration of a main part of an ink jet recording apparatus Side view showing the configuration of the main part of the inkjet recording apparatus Plane perspective view of the nozzle surface of the head Vertical section showing the internal structure of the head Schematic configuration diagram of ink circulation supply system Side view of the first embodiment of the nozzle surface cleaning device Front view of the first embodiment of the nozzle surface cleaning device The top view of 1st Embodiment of a nozzle surface cleaning apparatus Side view showing the second embodiment of the nozzle surface cleaning device Side view showing the third embodiment of the nozzle surface cleaning device The top view which shows 3rd Embodiment of a nozzle surface cleaning apparatus. Side view showing a modification of the third embodiment of the nozzle surface cleaning device The top view which shows 4th Embodiment of a nozzle surface cleaning apparatus. The top view which shows the modification of 4th Embodiment of a nozzle surface cleaning apparatus The top view which shows the modification of 4th Embodiment of a nozzle surface cleaning apparatus The top view which shows the modification of 4th Embodiment of a nozzle surface cleaning apparatus

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[1] First Embodiment << Configuration of Inkjet Recording Apparatus >>
First, the configuration of an ink jet recording apparatus to which the present invention is applied will be outlined.

  1, 2, and 3 are a front view, a plan view, and a side view, respectively, showing a configuration of a main part of an embodiment of an ink jet recording apparatus to which the present invention is applied.

  As shown in FIG. 1, the inkjet recording apparatus 10 is a single-pass line printer, and mainly includes a sheet conveying mechanism 20 that conveys a sheet (sheet) P and a sheet conveyed by the sheet conveying mechanism 20. A head unit 30 that ejects ink droplets of cyan (C), magenta (M), yellow (Y), and black (K) toward P, and a maintenance unit that performs maintenance of each head mounted on the head unit 30 40 and a nozzle surface cleaning device 100 that cleans the nozzle surface of each head mounted on the head unit 30.

  The paper transport mechanism 20 is constituted by a belt transport mechanism, and adsorbs the paper P to the traveling belt 22 and transports the paper P horizontally. The paper P is fed by a paper feeding mechanism (not shown).

  The head unit 30 mainly includes a head 50C that ejects cyan ink droplets, a head 50M that ejects magenta ink droplets, a head 50Y that ejects yellow ink droplets, and a head 50K that ejects black ink droplets. The head support frame 32 to which the heads 50C, 50M, 50Y, and 50K are attached, and a head support frame moving mechanism (not shown) that moves the head support frame 32 are configured.

  The heads (inkjet heads) 50C, 50M, 50Y, and 50K are constituted by line heads corresponding to the maximum paper width of the paper P to be printed. Since the configurations of the heads 50C, 50M, 50Y, and 50K are the same, in the following, they are described as the heads 50 unless otherwise distinguished.

  The head 50 (50C, 50M, 50Y, 50K) is formed in a rectangular block shape, and a nozzle surface 52 (52C, 52M, 52Y, 52K) is formed on the bottom thereof.

  FIG. 4 is a perspective plan view of the nozzle surface of the head.

  As shown in the figure, the nozzle 54 is disposed on the nozzle surface 52. The nozzles 54 are arranged at a constant pitch on a straight line along the longitudinal direction of the head 50 and constitute a nozzle row.

  The nozzle surface 52 is subjected to a liquid repellent treatment. The liquid repellent treatment is performed, for example, by coating the nozzle surface 52 with a liquid repellent film.

  FIG. 5 is a longitudinal sectional view showing the internal structure of the head. As shown in the figure, the nozzle 54 communicates with the pressure chamber 56.

  The pressure chamber 56 is formed as a rectangular parallelepiped space, and a nozzle 54 is formed at the center of the bottom surface.

  The ceiling surface of the pressure chamber 56 is composed of a diaphragm 58 and is formed to be deformable in the vertical direction. On the diaphragm 58, a piezoelectric element (piezo element) 60 is attached. The diaphragm 58 is deformed up and down by the piezoelectric element 60. Then, when the vibration plate 58 is deformed in the vertical direction, the pressure chamber 56 expands and contracts, and ink is ejected from the nozzle 54.

  The piezoelectric element 60 is driven by applying a predetermined drive voltage between an individual electrode (not shown) provided on the piezoelectric element 60 and a diaphragm 58 acting as a common electrode. A controller (a controller that controls the overall operation of the inkjet recording apparatus) selectively ejects ink from each nozzle 54 by individually controlling the driving of the piezoelectric element 60 corresponding to each nozzle 54.

  An individual supply channel 62 communicates with the pressure chamber 56. The individual supply channel 62 communicates with the common supply channel 64. The common supply flow path 64 communicates with the ink supply port 66. Ink is supplied from the ink tank to the ink supply port 66. In addition, an individual recovery flow path 68 communicates with the pressure chamber 56. The individual recovery channel 68 is communicated with the common recovery channel 70. The common recovery channel 70 communicates with the ink recovery port 72. The ink is collected from the ink collection port 72 to the ink tank. That is, ink is circulated and supplied to the pressure chamber 56.

  FIG. 6 is a schematic configuration diagram of an ink circulation supply system.

  The ink tank 200 is connected to the buffer tank 204 via a pipe line 202.

  A main pump 206 and a main valve 208 are provided in the pipe line 202. The main pump 206 sends the ink stored in the ink tank 200 to the buffer tank 204. The main valve 208 opens and closes the pipe line 202.

  The buffer tank 204 is opened to the atmosphere through an atmosphere opening hole 204A formed on the top surface.

  The buffer tank 204 is communicated with the supply tank 212 through the first supply channel 210. Further, the buffer tank 204 is communicated with the recovery tank 220 via the first recovery flow path 218.

  The supply tank 212 is communicated with the ink supply port 66 of the head 50 via the second supply channel 214.

  The recovery tank 220 is communicated with the ink recovery port 72 of the head 50 via the second recovery flow path 222.

  A supply pump 226 and a filter 228 are provided in the first supply channel 210. The supply pump 226 sends ink from the buffer tank 204 to the supply tank 212. The filter 228 is provided between the supply pump 226 and the buffer tank 204 and removes impurities from the ink supplied to the supply tank 212.

  A supply valve 230 is provided in the second supply channel 214. The supply valve 230 opens and closes the second supply channel 214.

  A recovery pump 232 is provided in the first recovery channel 218. The recovery pump 232 sends ink from the recovery tank 220 to the buffer tank 204.

  A recovery valve 234 is provided in the second recovery flow path 222. The collection valve 234 opens and closes the second supply channel 214.

  The supply tank 212 includes a supply liquid chamber 212 </ b> A and a supply gas chamber by an elastic film (a film body formed of an elastically deformable material (for example, rubber, thermoplastic elastomer, etc., particularly fluororubber, NBR)) 236. And 212B.

  A first supply channel 210 and a second supply channel 214 are communicated with the supply liquid chamber 212A. The ink supplied from the buffer tank 204 via the first supply channel 210 is temporarily stored in the supply liquid chamber 212A. Then, it is supplied from the supply liquid chamber 212 </ b> A to the head 50 via the second supply flow path 214.

  The supply gas chamber 212B is filled with gas. The supply gas chamber 212B communicates with an open air tube 240 that is open to the air. The atmosphere release pipe 240 is provided with an atmosphere release valve 242. The atmosphere release valve 242 opens and closes the atmosphere release pipe 240.

  In the supply tank 212, the pressure inside the supply liquid chamber 212 </ b> A is detected by the supply pressure detector 238.

  The configuration of the recovery tank 220 is the same as that of the supply tank 212, and the interior is partitioned into a recovery liquid chamber 220A and a recovery gas chamber 220B by an elastic film 244.

  A first recovery channel 218 and a second recovery channel 222 are communicated with the recovery liquid chamber 220A. The ink recovered from the head 50 via the second recovery flow path 222 is temporarily stored in the recovery liquid chamber 220A. Then, the liquid is recovered from the recovery liquid chamber 220 </ b> A to the buffer tank 204 via the first recovery flow path 218.

  The recovery gas chamber 220B is filled with gas. An air release pipe 248 that is open to the atmosphere communicates with the recovery gas chamber 220B. The atmosphere release pipe 248 is provided with an atmosphere release valve 250. The atmosphere release valve 250 opens and closes the atmosphere release pipe 248.

  In the recovery tank 220, the internal pressure of the recovery liquid chamber 220A is detected by a recovery pressure detector 246.

  The overall operation of the circulation supply system is controlled by a controller (a controller that controls the overall operation of the ink jet recording apparatus) (not shown). The controller circulates and supplies the ink to the head 50 by controlling the supply side pressure to be higher than the recovery side pressure by a predetermined amount. Specifically, the internal pressure of the supply liquid chamber 212A is P1, the internal pressure of the recovery liquid chamber 220A is P2, the back pressure of the nozzle is P3, and the pressure generated by the difference in height between the ink ejection surface and the supply pressure detector 238. When the difference (water head pressure) is H1, and the pressure difference (water head pressure) caused by the height difference between the ink ejection surface and the recovery pressure detector 246 is H2, P1 + H1> P3> P2 + H2 (mmH2O) A predetermined back pressure is applied to the nozzle to circulate the ink.

  The controller controls the supply pump 226 and the recovery pump 232 based on the internal pressure of the supply liquid chamber 212 </ b> A detected by the supply pressure detector 238 and the internal pressure of the recovery liquid chamber 220 </ b> A detected by the recovery pressure detector 246. The driving is controlled so that the internal pressure of the supply liquid chamber 212A and the internal pressure of the recovery liquid chamber 220A become predetermined pressures P1 and P2, respectively. Thereby, the ink is circulated and supplied to the head 50.

  Even when the pressure fluctuation occurs due to the operation of the supply pump 226 and the recovery pump 232, the pressure fluctuation is caused by the elastic film 236 provided in the supply tank 212 and the elastic film 244 provided in the recovery tank 220. Can be absorbed. Thereby, it is possible to supply ink while maintaining the back pressure constant.

  The head support frame 32 includes a head attachment portion (not shown) for attaching each head 50. Each head 50 is detachably attached to the head attachment portion.

  Each head 50 attached to the head support frame 32 is disposed perpendicular to the transport direction of the paper P with the nozzle surface 52 facing downward. Further, the paper P is arranged in a predetermined order with a constant interval along the conveyance direction of the paper P (in this example, arranged in the order of cyan, magenta, yellow, and black). Furthermore, each head 50 is disposed in parallel with the recording surface of the paper P transported by the paper transport mechanism 20 (the nozzles 52 are disposed horizontally in this example).

  The head mounting portion is provided on the head support frame 32 so as to be movable up and down, and is lifted and lowered by being driven by a lifting mechanism (not shown). Each head 50 attached to the head attaching portion is raised and lowered vertically with respect to the transport surface of the paper P by this lifting mechanism.

  A head support frame moving mechanism (not shown) slides the head support frame 32 horizontally in a direction orthogonal to the transport direction of the paper P. The head support frame moving mechanism includes, for example, a ceiling frame installed horizontally across the paper transport mechanism 20, a guide rail laid on the ceiling frame, a traveling body that slides on the guide rail, and its traveling It is comprised by the drive means (for example, feed screw mechanism etc.) which moves a body along a guide rail. The head support frame 32 is attached to the traveling body and slides horizontally.

  The head 50 attached to the head support frame 32 is slidable horizontally by moving the head support frame 32 by the head support frame moving mechanism.

  The head 50 slides horizontally and moves between the “image recording position” and the “maintenance position”.

  When the head 50 is located at the image recording position, the head 50 is disposed above the paper transport mechanism 20. As a result, it is possible to print on the paper P transported by the paper transport mechanism 20. On the other hand, when it is located at the maintenance position, it is disposed in the maintenance unit 40.

  The maintenance unit 40 includes a cap 42 (42C, 42M, 42Y, 42K) that covers the nozzle surface 52 of each head 50. When the apparatus is stopped for a long time, the head 50 is moved to the maintenance unit 40, and the nozzle surface 52 of the head 50 is covered with a cap. Thereby, non-discharge etc. by drying are prevented.

  The nozzle surface cleaning device 100 cleans the nozzle surface of each head mounted on the head unit 30. The nozzle surface cleaning device 100 cleans the nozzle surface 52 by bringing the cleaning liquid into contact with the nozzle surface 52 of the head 50 in the process in which the head 50 moves from the maintenance position toward the image recording position. The configuration of the nozzle surface cleaning device 100 will be described in detail later.

  The ink jet recording apparatus 10 is configured as described above. The overall operation of the inkjet recording apparatus 10 is controlled by a controller (not shown), and the controller executes a predetermined control program to control the operation of each unit of the inkjet recording apparatus 10.

<Image recording operation>
Next, an image recording operation by the inkjet recording apparatus 10 will be outlined.

  When execution of printing is instructed, the paper P is fed to the paper transport mechanism 20 from a paper feeding device (not shown). The paper P is continuously fed at regular intervals. The paper transport mechanism 20 receives the paper P fed from the paper feeder and continuously transports it at a constant speed.

  The controller controls the driving of each head 50 in accordance with the timing at which the paper P passes under the head 50, and ejects ink from the nozzles of each head 50. As a result, an image is recorded on the paper P.

<Configuration of nozzle surface cleaning device>
Next, the configuration of the nozzle surface cleaning device 100 will be described.

  The nozzle surface cleaning device 100 is provided for each head 50. The configuration of the nozzle surface cleaning device 100 that cleans each head 50 is the same.

  7, 8, and 9 are a side view, a front view, and a plan view of the nozzle surface cleaning device, respectively.

  As shown in the figure, the nozzle surface cleaning apparatus 100 mainly includes a cleaning liquid holding plate 102 that holds the cleaning liquid in a film shape with the nozzle surface 52, and a collection tray 112 that recovers the cleaning liquid dropped from the cleaning liquid holding plate 102. And a cleaning liquid supply mechanism 120 that supplies a cleaning liquid between the nozzle surface 52 and the cleaning liquid holding plate 102.

  The cleaning liquid holding plate 102 is formed in a rectangular plate shape. The upper surface portion of the cleaning liquid holding plate 102 is a cleaning liquid holding surface 104, and the cleaning liquid is held in a film shape between the cleaning liquid holding surface (upper surface portion) 104 and the nozzle surface 52.

  The cleaning liquid holding surface 104 is formed flat corresponding to the surface shape of the nozzle surface 52, and the length D of the side in the depth direction is the length of the nozzle surface 52 in the depth direction (perpendicular to the longitudinal direction of the head 50). (Length in the direction). On the other hand, the length of the side in the horizontal direction (width in the direction parallel to the longitudinal direction of the head 50) W is formed to be a predetermined length. Specifically, it is formed with a length necessary and sufficient for cleaning the nozzle surface 52. That is, by increasing the length of the side in the horizontal direction, the time during which the nozzle surface 52 is in contact with the cleaning liquid can be increased. However, if this length is increased, the apparatus becomes larger. Therefore, it is preferable to set the length necessary and sufficient for cleaning the nozzle surface 52 (if priority is given to downsizing, it is preferable to set the length to a minimum that allows sufficient cleaning).

  The cleaning liquid holding plate 102 is attached to the top of a support column 114 standing on the inner side of the collection tray 112 and is disposed at a predetermined position. Specifically, it is arranged on the moving path of the head 50.

  At this time, the cleaning liquid holding plate 102 is disposed so that the cleaning liquid holding surface 104 is horizontal. That is, the cleaning liquid holding surface 104 is disposed so as to be parallel to the nozzle surface 52. Further, the side of the cleaning liquid holding surface 104 in the depth direction is arranged so as to be orthogonal to the moving direction of the head 50, and the center of the side of the cleaning liquid holding surface 104 in the depth direction is the depth direction of the nozzle surface 52 of the head 50. It arrange | positions so that it may correspond with the center of. Thus, when the head 50 moves between the image recording position and the maintenance position, the nozzle surface 52 of the head 50 passes over the cleaning liquid holding surface 104 of the cleaning liquid holding plate 102. Further, when the nozzle surface 52 passes over the cleaning liquid holding surface 104, the nozzle surface 52 passes facing the cleaning liquid holding surface 104 (passes in a state parallel to each other).

  Further, the cleaning liquid holding plate 102 has a predetermined gap δ formed between the nozzle surface 52 of the head 50 and the cleaning liquid holding surface 104 when the nozzle surface 52 of the head 50 passes over the cleaning liquid holding surface 104. Placed in. This gap δ is formed between the cleaning liquid holding surface 104 and the nozzle surface 52 so as to have a width capable of holding the cleaning liquid in the form of a film. Accordingly, the cleaning liquid can be held in a film shape between the nozzle surface 52 and the cleaning liquid holding surface 104 in the region facing the cleaning liquid holding surface 104.

  The cleaning liquid is supplied onto the cleaning liquid holding surface 104 from a pair of cleaning liquid supply holes 106 formed in the cleaning liquid holding surface 104. The cleaning liquid supply hole 106 is arranged on one side (maintenance position side) on the cleaning liquid holding surface, and the moving direction of the cleaning liquid holding surface 104 when cleaning the nozzle surface 52 (the relative moving direction of the cleaning liquid holding surface 104 with respect to the nozzle surface 52) ) On the upstream side. That is, as described above, the nozzle surface cleaning apparatus 100 cleans the nozzle surface 52 in the process of moving the head 50 from the maintenance position to the image recording position, so that the supplied cleaning liquid spreads over the entire surface of the cleaning liquid holding surface 104. In addition, the cleaning liquid supply hole 106 is disposed at a position near the maintenance position on the upstream side in the movement direction. Thereby, the cleaning liquid can be efficiently supplied to almost the entire surface of the cleaning liquid holding surface 104 during cleaning.

  Each cleaning liquid supply hole 106 communicates with a cleaning liquid supply port 110 formed on the lower surface of the cleaning liquid holding plate 102 via a cleaning liquid supply channel 108 formed inside the cleaning liquid holding plate 102. Therefore, if the cleaning liquid is supplied from the cleaning liquid supply port 110, the cleaning liquid can be supplied onto the cleaning liquid holding surface 104 from each cleaning liquid supply hole 106.

  As described above, the nozzle surface 52 is subjected to the liquid repellent treatment, but the cleaning liquid holding surface 104 is formed to have higher wettability than the nozzle surface 52 subjected to the liquid repellent treatment. That is, the cleaning liquid holding surface 104 is formed so that the contact angle is smaller than the contact angle of the nozzle surface 52. Thereby, it is possible to easily drag the cleaning liquid to the moving nozzle surface 52, and it is possible to prevent the cleaning liquid from remaining on the nozzle surface 52.

  The collection tray 112 is formed in a dish shape whose upper surface is open, and is installed horizontally on the gantry 116. The gantry 116 is attached to a main body frame (not shown) of the inkjet recording apparatus 10 via a bracket (not shown). A drainage port 118 is formed in the collection tray 112. The drain port 118 is connected to a drain tank (not shown) via a drain pipe (not shown).

  Within the collection tray 112, a support column 114 is erected vertically, and the cleaning liquid holding plate 102 is attached to the top of the support column 114.

  The cleaning liquid overflowing from between the nozzle surface 52 and the cleaning liquid holding surface 104 is recovered by the recovery tray 112.

  The cleaning liquid supply mechanism 120 mainly supplies a cleaning liquid tank 124 that stores the cleaning liquid, a cleaning liquid pipe 126 that connects the cleaning liquid supply port 110 and the cleaning liquid tank 124 of the cleaning liquid holding plate 102, and the cleaning liquid from the cleaning liquid tank 124 to the cleaning liquid supply port 110. A cleaning liquid pump 128 that feeds liquid and a cleaning liquid valve 130 that opens and closes the pipe of the cleaning liquid pipe 126 are configured.

  The cleaning liquid tank 124 stores cleaning liquid. For example, a liquid containing a component that dissolves ink stains is used as the cleaning liquid.

  The cleaning liquid pipe 126 connects the cleaning liquid tank 124 and the cleaning liquid supply port 110 formed in the cleaning liquid holding plate 102.

  The cleaning liquid pump 128 is provided in the middle of the cleaning liquid pipe 126 and sends the cleaning liquid from the cleaning liquid tank 124 to the cleaning liquid nozzle 122.

  The cleaning liquid valve 130 is provided in the middle of the cleaning liquid pipe 126 and opens and closes the pipe of the cleaning liquid pipe 126.

  The operation of the cleaning liquid supply mechanism 120 is controlled by a controller (a controller that controls the overall operation of the inkjet recording apparatus) (not shown).

  The nozzle surface cleaning device 100 is configured as described above.

<Nozzle surface cleaning operation by nozzle surface cleaning device>
Next, the cleaning operation of the nozzle surface 52 by the nozzle surface cleaning apparatus 100 will be described.

  As described above, the nozzle surface 52 is cleaned in the process of moving the head 50 from the maintenance position to the image recording position. Therefore, the nozzle surface 52 is cleaned, for example, when the head 50 returns from the maintenance position to the image recording position after maintenance. Therefore, here, a case where the operation is performed after maintenance will be described as an example.

  When a return from the maintenance position to the image recording position is instructed, the head support frame moving mechanism is driven. Thereby, the head 50 starts moving toward the image recording position.

  The movement of the head 50 is stopped when the tip portion in the moving direction (the end on the image recording position side) reaches the nozzle surface cleaning device 100. As a result, the tip portion of the nozzle surface 52 (the end portion on the image recording position side) is disposed above the cleaning liquid holding surface 104 of the cleaning liquid holding plate 102 with a predetermined gap δ (state of FIG. 7).

  When the movement of the head 50 is stopped and the tip portion of the nozzle surface 52 is disposed above the cleaning liquid holding surface 104, the supply of the cleaning liquid is started between the nozzle surface 52 and the cleaning liquid holding surface 104. As a result, a cleaning liquid film is formed between the cleaning liquid holding surface 104 and the nozzle surface 52. The cleaning liquid is continuously supplied between the cleaning liquid holding surface 104 and the nozzle surface 52, and a surplus is dropped from the cleaning liquid holding plate 102 and recovered by the recovery tray 112.

  When a certain time elapses from the start of the supply of the cleaning liquid and a film of the cleaning liquid is formed between the cleaning liquid holding surface 104 and the nozzle surface 52, the head support frame moving mechanism is driven again, and the head 50 is moved to the image recording position again. Start moving towards. At this time, the head 50 moves on the cleaning liquid holding surface 104 while the nozzle surface 52 touches the cleaning liquid held on the cleaning liquid holding surface 104 (moves without contact with the cleaning liquid holding surface 104). Ink stains and the like adhering to the nozzle surface 52 are dissolved by touching the cleaning liquid and removed from the nozzle surface 52.

  On the other hand, simply moving the head 50 and causing the nozzle surface 52 to come into contact with the cleaning liquid may cause the cleaning liquid containing dirt to adhere to and remain on the nozzle surface 52.

  Therefore, in the nozzle surface cleaning device 100 of the present embodiment, the movement of the head 50 is controlled so that the cleaning liquid does not remain on the nozzle surface 52. That is, the movement (movement speed) of the head 50 is performed so that the film-like cleaning liquid held between the nozzle surface 52 and the cleaning liquid holding surface 104 is dragged to the cleaning liquid holding surface 104 and remains on the cleaning liquid holding surface 104 side. ) Is controlled. Thereby, the nozzle surface 52 can be cleaned without leaving the cleaning liquid.

  In the nozzle surface cleaning apparatus 100 of the present embodiment, the wettability of the cleaning liquid holding surface 104 is made higher than that of the nozzle surface 52 (the contact angle of the cleaning liquid holding surface 104 is made smaller than the contact angle of the nozzle surface 52). Therefore, the cleaning liquid is easily dragged to the cleaning liquid holding surface 104 side, and if the head 50 is moved at a constant speed or less, the nozzle surface 52 can be cleaned without leaving the cleaning liquid. .

  Here, if the moving speed of the head 50 is too slow, the time required for cleaning becomes long. Therefore, the moving speed of the head 50 is preferably set to the maximum speed in a speed range in which the cleaning liquid does not remain on the nozzle surface 52. .

  Whether or not the cleaning liquid remains on the nozzle surface 52 when the head 50 is moved at a constant speed depends on the wettability (liquid repellency) of the nozzle surface 52 and the cleaning liquid holding surface 104, the surface tension of the cleaning liquid, and the cleaning liquid holding. The moving speed of the head 50 is determined in consideration of the thickness of the cleaning liquid formed between the surface 104 and the nozzle surface 52, the degree of contamination, and the like. Alternatively, an experiment for examining the remaining state of the cleaning liquid by changing the moving speed of the head 50 is performed, and the moving speed of the head 50 is determined from the result of this experiment.

  Thus, the nozzle surface 52 is cleaned by moving the head 50 so that the cleaning liquid does not remain on the nozzle surface 52 and bringing the cleaning liquid into contact with the nozzle surface 52. At this time, since the cleaning liquid held between the nozzle surface 52 and the cleaning liquid holding surface 104 generates a flow due to the movement of the nozzle surface 52, the dirt can be efficiently removed.

  When the rear end (the end on the maintenance position side) of the head 50 passes over the cleaning liquid holding surface 104, the supply of the cleaning liquid is stopped.

  The head 50 moves toward the image recording position as it is, and when the head 50 reaches the image recording position, the movement is stopped.

  Thus, the cleaning of the head 50 is completed. Thus, in the nozzle surface cleaning apparatus 100 of the present embodiment, the nozzle surface 52 is cleaned by moving the head 50 so that no cleaning liquid remains on the nozzle surface 52. Thereby, the nozzle surface 52 can be cleaned completely without contact. Further, the cleaning liquid only needs to be supplied in a film form between the nozzle surface 52 and the cleaning liquid holding surface 104, so that it can be used economically.

  In this embodiment, the cleaning liquid supply holes 106 are formed at two locations on the cleaning liquid holding surface 104, but the number of the cleaning liquid supply holes 106 is not particularly limited. In consideration of the size of the cleaning liquid holding surface 104 and the like, it is preferable to increase or decrease the thickness appropriately. Further, the shape thereof is not particularly limited, and it may be formed in a slit shape (a slit shape orthogonal to the moving direction of the head 50) in addition to a circle as in the above embodiment.

[2] Second Embodiment << Device Configuration >>
FIG. 10 is a side view showing a second embodiment of the nozzle surface cleaning device according to the present invention.

  The nozzle surface cleaning device 100 of the present embodiment is different from the nozzle surface cleaning device 100 of the first embodiment described above in that the cleaning liquid used for cleaning the nozzle surface 52 can be switched. Therefore, only the cleaning liquid switching mechanism will be described below.

  As shown in FIG. 10, the cleaning liquid supply mechanism 120 provided in the nozzle surface cleaning apparatus of the present embodiment mainly includes a first cleaning liquid tank 124A for storing the first cleaning liquid and a second cleaning liquid for storing the second cleaning liquid. The cleaning liquid tank 124B, the first cleaning liquid tank 126A that connects the first cleaning liquid tank 124A and the cleaning liquid supply port 110 of the cleaning liquid holding plate 102, and the second cleaning liquid tank 124B and the cleaning liquid supply port 110 of the cleaning liquid holding plate 102 are connected. The second cleaning liquid pipe 126B, the first cleaning liquid pump 128A that sends the first cleaning liquid from the first cleaning liquid tank 124A to the cleaning liquid supply port 110, and the second cleaning liquid that is sent from the second cleaning liquid tank 124B to the cleaning liquid supply port 110 The second cleaning liquid pump 128B for liquid and the first cleaning liquid valve 13 for opening and closing the pipe line of the first cleaning liquid pipe 126A. And A, composed of the second cleaning liquid valve 130B for opening and closing the conduit of the second cleaning liquid pipe 126B.

  The first cleaning liquid tank 124A stores the first cleaning liquid.

  The second cleaning liquid tank 124B stores the second cleaning liquid.

  The first cleaning liquid pipe 126A connects the first cleaning liquid tank 124A and the cleaning liquid supply port 110 formed in the cleaning liquid holding plate 102.

  The second cleaning liquid pipe 126B connects the second cleaning liquid tank 124B and the cleaning liquid supply port 110 formed in the cleaning liquid holding plate 102.

  The first cleaning liquid pump 128A is provided in the middle of the first cleaning liquid pipe 126A, and sends the first cleaning liquid from the first cleaning liquid tank 124A to the cleaning liquid nozzle 122.

  The second cleaning liquid pump 128B is provided in the middle of the second cleaning liquid pipe 126B, and sends the second cleaning liquid from the second cleaning liquid tank 124B to the cleaning liquid nozzle 122.

  The first cleaning liquid valve 130A is provided in the middle of the first cleaning liquid pipe 126A, and opens and closes the pipe line of the first cleaning liquid pipe 126A.

  The second cleaning liquid valve 130B is provided in the middle of the second cleaning liquid pipe 126B, and opens and closes the pipe line of the second cleaning liquid pipe 126B.

  The operation of the cleaning liquid supply mechanism 120 is controlled by a controller (a controller that controls the overall operation of the inkjet recording apparatus) (not shown).

<Action>
As described above, the nozzle surface cleaning apparatus 100 according to the present embodiment can switch the cleaning liquid used for cleaning the nozzle surface 52. Therefore, by storing different types of cleaning liquids in the first cleaning liquid tank 124A and the second cleaning liquid tank 124B, for example, it is possible to perform cleaning according to the degree of contamination.

  For example, the first cleaning liquid tank 124A stores a cleaning liquid having a high cleaning capacity (for example, a cleaning liquid containing a component that dissolves ink stains), and the second cleaning liquid tank 124B has a lower cleaning capacity than the first cleaning liquid. Store the cleaning solution. When the degree of dirt is high or when a certain time or more has passed since the previous cleaning, the first cleaning liquid is used for cleaning. On the other hand, when the degree of dirt is low or when not much time has passed since the previous cleaning, the second cleaning liquid is used for cleaning. Thereby, the nozzle surface 52 can be appropriately cleaned according to the degree of contamination. In this case, the moving speed of the head 50 may be changed between the case where the first cleaning liquid is used and the case where the second cleaning liquid is used. Thereby, the nozzle surface 52 can be cleaned more appropriately.

  Further, the nozzle surface 52 can be cleaned a plurality of times by switching the cleaning liquid. That is, for example, in the case of cleaning twice, the first cleaning is performed using a cleaning liquid having a high cleaning capability, and the second cleaning is performed using a cleaning liquid having a higher surface tension than the first cleaning liquid (pure water is preferred). to clean up. Thereby, the dirt adhering to the nozzle surface 52 can be removed by the first cleaning, and the cleaning liquid remaining on the nozzle surface can be removed by the second cleaning.

  Hereinafter, the case where the cleaning liquid is switched to clean the nozzle surface 52 a plurality of times will be described.

  In this example, the case where the nozzle surface 52 is cleaned twice will be described as an example. In this case, the first cleaning is performed using a cleaning liquid having a high cleaning capability, and the second cleaning is performed using a cleaning liquid having a surface tension higher than that of the first cleaning liquid. Therefore, the first cleaning liquid tank 124A stores a cleaning liquid having a high cleaning ability (for example, a cleaning liquid containing a component that dissolves ink stains), and the second cleaning liquid tank 124B has a higher surface tension than the first cleaning liquid. A cleaning liquid (pure water in this example) is stored.

  Both the first cleaning and the second cleaning are performed in the process of moving the head 50 from the maintenance position to the image recording position.

  In order to perform the first cleaning, first, the head 50 starts to move from the maintenance position toward the image recording position.

  The movement of the head 50 is stopped when the tip portion in the moving direction (the end on the image recording position side) reaches the nozzle surface cleaning device 100. As a result, the tip end portion (the end portion on the image recording position side) of the nozzle surface 52 is disposed above the cleaning liquid holding surface 104 of the cleaning liquid holding plate 102 with a predetermined gap δ (state shown in FIG. 10).

  When the movement of the head 50 is stopped and the tip portion of the nozzle surface 52 is disposed above the cleaning liquid holding surface 104, the supply of the first cleaning liquid is started between the nozzle surface 52 and the cleaning liquid holding surface 104. That is, the first cleaning liquid valve 130A is opened and the first cleaning liquid pump 128A is driven. As a result, a first cleaning liquid film having a high cleaning capability is formed between the cleaning liquid holding surface 104 and the nozzle surface 52.

  When a predetermined time has elapsed after the supply of the first cleaning liquid has started and a film of the first cleaning liquid is formed between the cleaning liquid holding surface 104 and the nozzle surface 52, the head support frame moving mechanism is re-driven. The head 50 starts moving again toward the image recording position. At this time, the head 50 moves on the cleaning liquid holding surface 104 while the nozzle surface 52 touches the first cleaning liquid held on the cleaning liquid holding surface 104. Ink stains and the like adhering to the nozzle surface 52 are dissolved by touching the first cleaning liquid and removed from the nozzle surface 52.

  As in the first embodiment, the movement of the head 50 is controlled so that the first cleaning liquid does not remain on the nozzle surface 52. Thereby, it is possible to prevent the first cleaning liquid from remaining on the nozzle surface 52.

  When the rear end portion (the end portion on the maintenance position side) of the head 50 passes over the cleaning liquid holding surface 104, the supply of the first cleaning liquid is stopped. That is, the first cleaning liquid valve 130A is closed and the driving of the first cleaning liquid pump 128A is stopped.

  The head 50 moves toward the image recording position as it is, and when the head 50 reaches the image recording position, the movement is stopped. Thus, the first cleaning is completed.

  Next, a second cleaning is performed. In order to perform the second cleaning, the head 50 moves again to the maintenance position.

  When the head 50 reaches the maintenance position, the direction is changed and the movement starts from the maintenance position toward the image recording position.

  The movement of the head 50 is stopped when the tip portion in the moving direction (the end on the image recording position side) reaches the nozzle surface cleaning device 100. As a result, the tip end portion (the end portion on the image recording position side) of the nozzle surface 52 is disposed above the cleaning liquid holding surface 104 of the cleaning liquid holding plate 102 with a predetermined gap δ (state shown in FIG. 10).

  When the movement of the head 50 is stopped and the tip portion of the nozzle surface 52 is disposed above the cleaning liquid holding surface 104, the supply of the second cleaning liquid is started between the nozzle surface 52 and the cleaning liquid holding surface 104. That is, the second cleaning liquid valve 130B is opened and the second cleaning liquid pump 128B is driven. Thereby, a film of the second cleaning liquid (in this example, pure water) is formed between the cleaning liquid holding surface 104 and the nozzle surface 52.

  When a certain period of time has elapsed after the supply of the second cleaning liquid is started and the second cleaning liquid film is formed between the cleaning liquid holding surface 104 and the nozzle surface 52, the head support frame moving mechanism is re-driven. The head 50 starts moving again toward the image recording position. At this time, the head 50 moves on the cleaning liquid holding surface 104 while the nozzle surface 52 touches the second cleaning liquid held on the cleaning liquid holding surface 104. Here, in the second cleaning, since the cleaning liquid having a higher surface tension than that in the first cleaning is used, it is possible to prevent the cleaning liquid from remaining on the nozzle surface 52 more effectively. Thereby, for example, even when the cleaning liquid cannot be prevented from remaining on the nozzle surface 52 by the first cleaning, the remaining cleaning liquid can be captured by the second cleaning, and the nozzle can be effectively used. Adhesion to the surface 52 can be prevented.

  In this second cleaning, the movement of the head 50 is controlled so that the second cleaning liquid does not remain on the nozzle surface 52.

  When the rear end portion (the end portion on the maintenance position side) of the head 50 passes over the cleaning liquid holding surface 104, the supply of the second cleaning liquid is stopped. That is, the second cleaning liquid valve 130B is closed and the driving of the second cleaning liquid pump 128B is stopped.

  The head 50 moves toward the image recording position as it is, and when the head 50 reaches the image recording position, the movement is stopped.

  Thus, the cleaning of the head 50 is completed. In this way, by cleaning the nozzle surface 52 a plurality of times by changing the type of the cleaning liquid, it is possible to effectively prevent the cleaning liquid from remaining on the nozzle surface 52 while effectively removing the dirt on the nozzle surface 52. it can.

  In the above example, only two types of cleaning liquids can be switched, but more types of cleaning liquids may be switched.

  In the above example, the case where the cleaning is performed twice using two types of cleaning liquids has been described as an example. However, the cleaning may be performed a plurality of times using a plurality of types of cleaning liquids.

  Moreover, it can also be set as the structure cleaned many times using two types of washing | cleaning liquids. For example, it can also be set as the structure cleaned several times using a 1st washing | cleaning liquid, and finally cleaning using a 2nd washing | cleaning liquid. That is, at least the last time can be cleaned with the second cleaning liquid (cleaning liquid with high surface tension).

  In the above example, the nozzle surface 52 is cleaned in the process of moving the head 50 from the maintenance position to the image recording position twice, but the first time the head 50 is moved from the maintenance position to the image recording position. The second cleaning may be performed in the process of returning the head 50 from the image recording position to the maintenance position. That is, the nozzle surface 52 can be cleaned by both reciprocating movements of the head 50. In this case, it is preferable to form the cleaning liquid supply hole 106 at the center position of the cleaning liquid holding surface 104.

[3] Third Embodiment FIGS. 11 and 12 are a side view and a plan view, respectively, showing a third embodiment of the nozzle surface cleaning apparatus according to the present invention.

  As shown in the figure, the nozzle surface cleaning apparatus 100 according to the present embodiment has the nozzle surface according to the first embodiment described above in that a cleaning liquid recovery hole for recovering the cleaning liquid is formed in the cleaning liquid holding plate 102. Different from the cleaning device 100. Therefore, only the configuration of the cleaning liquid holding plate 102 will be described below.

  As shown in FIGS. 11 and 12, the cleaning liquid holding plate 102 of the present embodiment has a slit-shaped dividing groove 140 formed on the cleaning liquid holding surface 104, and the cleaning liquid holding surface 104 becomes a cleaning region by the dividing groove 140. It is divided into 104A and cleaning liquid recovery area 104B. The dividing groove 140 is formed orthogonal to the moving direction of the head 50 (= longitudinal direction of the head 50), and is formed so as to penetrate the lower surface of the cleaning liquid holding plate 102. The cleaning liquid holding surface 104 is divided into a cleaning area 104A and a cleaning liquid recovery area 104B before and after the dividing groove 140. That is, the cleaning region 104A located on the upstream side in the moving direction of the cleaning liquid holding surface 104 during the cleaning of the nozzle surface 52 (the relative moving direction of the cleaning liquid holding surface 104 with respect to the nozzle surface 52), and the cleaning liquid recovery located on the downstream side The area 104B is divided.

  The cleaning area 104 </ b> A is an area used for cleaning the nozzle surface 52, and the cleaning liquid is supplied between the cleaning area 104 </ b> A and the nozzle surface 52 to clean the nozzle surface 52. Accordingly, the cleaning liquid supply hole 106 is formed in the cleaning region 104A.

  On the other hand, the cleaning liquid recovery area 104B is an area for capturing the cleaning liquid remaining on the nozzle surface 52, and a plurality of cleaning liquid recovery holes 142 for recovering the cleaning liquid are formed. The cleaning liquid recovery hole 142 is formed in a slit shape and is formed orthogonal to the moving direction (longitudinal direction) of the head 50. The cleaning liquid recovery holes 142 are arranged in parallel at regular intervals along the movement direction (longitudinal direction) of the head 50.

  The cleaning liquid holding plate 102 of the present embodiment is configured as described above.

  According to the nozzle surface cleaning apparatus 100 of the present embodiment, the slit-shaped cleaning liquid recovery hole 142 is formed in the cleaning liquid holding surface 104, thereby further effectively preventing the cleaning liquid from remaining on the nozzle surface 52. Can do. That is, as described above, the cleaning liquid holding surface 104 is formed with higher wettability than the nozzle surface 52, and the movement of the head 50 is controlled so that the cleaning liquid does not remain on the nozzle surface 52. Even when the cleaning liquid cannot be completely dragged by 104A and the cleaning liquid remains on the nozzle surface 52, the cleaning liquid remaining on the nozzle surface 52 is recovered (trapped) by the slit-shaped cleaning liquid recovery hole 142 formed in the cleaning liquid recovery area 104B. ), The nozzle surface 52 can be cleaned more reliably without leaving the cleaning liquid on the nozzle surface 52.

  The number of cleaning liquid recovery holes 142 is not particularly limited, and is preferably formed by appropriately increasing or decreasing depending on the size of the cleaning liquid holding surface 104 or the like.

  Further, the width of the cleaning liquid recovery hole 142 is set to a width capable of capturing the cleaning liquid. Although this depends on the cleaning liquid used, it is set to a width of about 1 mm to several hundred μm, for example.

  In this example, the cleaning liquid recovery holes 142 are formed with the same width, but the cleaning liquid recovery holes 142 may be formed with different widths. In particular, the width is stepwise toward the image recording position (the downstream side of the moving direction of the cleaning liquid holding surface 104 (the relative moving direction of the cleaning liquid holding surface 104 with respect to the nozzle surface 52) when cleaning the nozzle surface 52). It is preferable to form so as to be narrow. Accordingly, the cleaning liquid remaining on the nozzle surface 52 can be captured in stages according to the size of the droplets of the cleaning liquid remaining on the nozzle surface 52 (can be captured in stages from a larger size), and the cleaning liquid remaining on the nozzle surface 52 can be captured more efficiently. Can do.

  Further, as shown in FIG. 13, a suction mechanism 144 may be connected to the cleaning liquid recovery hole 142 to forcibly suck the cleaning liquid from the cleaning liquid recovery hole 142.

  The suction mechanism 144 is mainly composed of a drainage tank 146, a suction pipe 148, and a suction pump 150.

  The drainage tank 146 stores the cleaning liquid recovered from each cleaning liquid recovery hole 142 by suction.

  The suction pipe 148 connects each cleaning liquid recovery hole 142 and the drainage tank 146, and guides the cleaning liquid recovered from each cleaning liquid recovery hole 142 to the drainage tank 146.

  The suction pump 150 is installed in the middle of the suction pipe 148. By driving the suction pump 150, the cleaning liquid is sucked from each cleaning liquid recovery hole 142 and sent to the drainage tank 146.

  By providing such a suction mechanism 144, the cleaning liquid remaining on the nozzle surface 52 can be more reliably removed.

  Note that if suction is performed from the cleaning liquid recovery hole 142 in this way, ink may be sucked out from the nozzle 54. Therefore, when cleaning the nozzle surface 52 while suctioning from the cleaning liquid recovery hole 142 in this way, the back of the head 50 is removed. It is preferable to clean while adjusting the pressure. Specifically, it is preferable to clean the head 50 with a negative back pressure so that ink is not sucked out of the nozzles 54.

  In the example illustrated in FIG. 13, the suction is performed from all the cleaning liquid recovery holes 142, but the suction may be performed from only a part of the cleaning liquid recovery holes 142.

[4] Fourth Embodiment FIG. 14 is a plan view showing a fourth embodiment of the nozzle surface cleaning apparatus according to the present invention.

  As shown in the figure, the nozzle surface cleaning apparatus 100 according to the present embodiment has a rear end portion of the cleaning liquid holding plate 102 (the moving direction of the cleaning liquid holding surface 104 when cleaning the nozzle surface 52 (the cleaning liquid holding surface with respect to the nozzle surface 52). The nozzle surface of the first embodiment described above in that the rear end portion (= end portion on the image recording position side) 152) is formed so as to converge on one side in the width direction. Different from the cleaning device 100. Therefore, only the configuration of the cleaning liquid holding plate 102 will be described below.

  As shown in FIG. 14, the rear end portion 152 (= the rear end portion of the cleaning liquid holding surface 104) of the cleaning liquid holding plate 102 converges on one side in the width direction (direction perpendicular to the moving direction of the cleaning liquid holding surface 104). Formed into a triangular shape (formed in a shape having a vertex on one side in the width direction).

  Thus, by forming the rear end portion of the cleaning liquid holding plate 102 so as to converge, as shown in FIG. 15, the rear end portion of the head 50 (the rear end portion in the moving direction during cleaning of the nozzle surface 52 (= When the end of the maintenance position side)) passes through the cleaning liquid holding surface 104, the cleaning liquid can be collected at the end of the nozzle surface 52 in the width direction by the action of the inclined portion of the rear end 152 of the cleaning liquid holding plate 102. . As a result, it is possible to improve the liquid cutting property when the nozzle surface 52 is separated from the cleaning liquid holding surface 104, and it is possible to effectively prevent the cleaning liquid from adhering to the end of the nozzle surface 52.

  In the above example, the rear end 152 of the cleaning liquid holding plate 102 is converged to one side in the width direction, but may be converged to the center in the width direction as shown in FIG. Or as shown in FIG. 17, you may make it the shape converged on both the edge parts of the width direction. However, since the nozzles 54 are usually arranged in the center of the nozzle surface 52, it is preferable to have a shape that converges at the end in the width direction.

  Also in the cleaning liquid holding plate of the present embodiment, a cleaning liquid recovery hole may be formed in the rear end portion, similarly to the cleaning liquid holding plate of the third embodiment.

<< Other embodiments >>
In the above embodiment, the nozzle surface cleaning device is fixed and the head side is moved to clean the head nozzle surface. However, the nozzle surface cleaning device side is moved to clean the head nozzle surface. It can also be configured. Moreover, it can also be set as the structure which moves both a head and a nozzle surface cleaning apparatus, and cleans the nozzle surface of a head.

  Further, the nozzle surface cleaning apparatus of the present invention forms a liquid film between the cleaning liquid holding surface and the nozzle surface and cleans the nozzle surface, so that a liquid film is formed between the cleaning liquid holding surface and the nozzle surface. It is preferable to install a sensor for detecting whether or not it is present. Thereby, a liquid film can be reliably formed and cleaned. The detection of whether or not the liquid film is formed is configured, for example, by setting a predetermined detection area on the cleaning liquid holding surface and detecting the presence or absence of the liquid film by detecting a change in capacitance of the detection area. can do. Moreover, it can also be set as the structure which detects the presence or absence of a liquid film by detecting the change of the resistance value of a detection region.

  The cleaning liquid used for cleaning may be a room temperature cleaning liquid. For example, a cleaning liquid tank may be provided with a heating mechanism (for example, a heater), and the cleaning liquid heated to a predetermined temperature may be used. Thereby, the cleaning effect can be improved. In this case, for example, the temperature of the cleaning liquid holding surface 104 can be detected to detect the presence or absence of a liquid film.

  Moreover, in the said embodiment, although the nozzle surface cleaning apparatus is fixed and installed, you may make it the whole so that raising / lowering is possible and can adjust the space | interval of the clearance gap between a washing | cleaning liquid holding surface and a nozzle surface. Thereby, the cleaning liquid holding surface can be adjusted and set at a position where the liquid can be reliably held between the nozzle surface.

  DESCRIPTION OF SYMBOLS 10 ... Inkjet recording device, 20 ... Paper conveyance mechanism, 22 ... Belt, 30 ... Head unit, 32 ... Head support frame, 42 ... Cap, 50 (50C, 50M, 50Y, 50K) ... Head, 52 ... Nozzle surface, 54 ... Nozzle, 56 ... Pressure chamber, 58 ... Diaphragm, 60 ... Piezoelectric element, 62 ... Individual supply channel, 64 ... Common supply channel, 66 ... Ink supply port, 68 ... Individual recovery channel, 70 ... Common recovery flow 72: Ink recovery port, 100 ... Nozzle surface cleaning device, 102 ... Cleaning liquid holding plate, 104 ... Cleaning liquid holding surface, 104A ... Cleaning area, 104B ... Cleaning liquid recovery area, 106 ... Cleaning liquid supply hole, 108 ... Cleaning liquid supply flow path , 110 ... cleaning liquid supply port, 112 ... collection tray, 114 ... support, 116 ... mount, 118 ... drainage port, 120 ... cleaning liquid supply mechanism, 122 ... cleaning liquid nozzle, 24 ... Cleaning liquid tank, 124A ... First cleaning liquid tank, 124B ... Second cleaning liquid tank, 126 ... Cleaning liquid piping, 126A ... First cleaning liquid piping, 126B ... Second cleaning liquid piping, 128 ... Cleaning liquid pump, 128A ... First cleaning liquid pump, 128B ... second cleaning liquid pump, 130 ... cleaning liquid valve, 130A ... first cleaning liquid valve, 130B ... second cleaning liquid valve, 140 ... divided groove, 142 ... cleaning liquid recovery hole, 144 ... suction mechanism, 146 ... drainage tank, 148 ... Suction piping, 150 ... suction pump, 152 ... rear end of cleaning liquid holding plate (= rear end of cleaning liquid holding surface), 200 ... ink tank, 202 ... pipe, 204 ... buffer tank, 204A ... air opening hole, 206 ... Main pump, 208 ... Main valve, 210 ... First supply flow path, 212 ... Supply tank, 212A ... Supply Body chamber, 212B ... supply gas chamber, 214 ... second supply channel, 218 ... first recovery channel, 220 ... recovery tank, 220A ... recovery liquid chamber, 220B ... recovery gas chamber, 222 ... second recovery channel, 226 ... Supply pump, 228 ... Filter, 230 ... Supply valve, 232 ... Recovery pump, 234 ... Recovery valve, 236 ... Elastic membrane, 238 ... Supply pressure detector, 240 ... Air release pipe, 242 ... Air release valve, 244 ... Elastic membrane, 246 ... Recovery pressure detector, 248 ... Air release pipe, 250 ... Air release valve

Claims (11)

In a nozzle surface cleaning device for cleaning the nozzle surface of an inkjet head,
A cleaning liquid holding surface having higher wettability than the nozzle surface, and the cleaning liquid holding surface is disposed to face the nozzle surface, and the cleaning liquid is formed into a film between the cleaning liquid holding surface and the nozzle surface. A cleaning liquid holding member to hold,
Cleaning liquid supply means for supplying the cleaning liquid between the cleaning liquid holding surface and the nozzle surface;
Moving means for relatively moving the cleaning liquid holding member and the inkjet head so that the cleaning liquid holding surface relatively moves along the nozzle surface;
Movement control means for controlling the movement means to control relative movement of the cleaning liquid holding member and the inkjet head so that the cleaning liquid does not remain on the nozzle surface;
A nozzle surface cleaning device comprising:   The cleaning liquid holding member has a cleaning liquid supply hole in the cleaning liquid holding surface, and the cleaning liquid supply means supplies the cleaning liquid from the cleaning liquid supply hole between the cleaning liquid holding surface and the nozzle surface. The nozzle surface cleaning apparatus according to claim 1.   The nozzle surface cleaning device according to claim 2, wherein the cleaning liquid supply hole is formed on an upstream side in a moving direction of the cleaning liquid holding surface relative to the nozzle surface.   4. The nozzle surface cleaning device according to claim 1, wherein the cleaning liquid supply unit is configured to be able to selectively supply the different types of cleaning liquid. 5. A cleaning liquid supply control means for controlling supply of the cleaning liquid by the cleaning liquid supply means;
The movement control means relatively moves the cleaning liquid holding surface and the nozzle surface a plurality of times to clean the nozzle surface a plurality of times,
5. The nozzle surface cleaning apparatus according to claim 4, wherein the cleaning liquid supply control unit switches the type of the cleaning liquid supplied between the cleaning liquid holding surface and the nozzle surface in accordance with the number of cleanings. The cleaning liquid supply means is configured to be able to selectively supply the cleaning liquid having different surface tensions,
6. The nozzle surface cleaning apparatus according to claim 5, wherein the cleaning liquid supply control unit switches from a cleaning liquid having a low surface tension to a cleaning liquid having a high surface tension in accordance with the number of times of cleaning.   7. The slit-like cleaning liquid recovery hole is formed in a region downstream of the cleaning liquid holding surface in the relative movement direction of the cleaning liquid holding surface with respect to the nozzle surface. The nozzle surface cleaning apparatus of 1 item | term.   The cleaning liquid recovery hole is formed in parallel at a plurality of locations along the relative movement direction of the cleaning liquid holding surface and the nozzle surface, and has a stepwise width toward the downstream side in the relative movement direction. The nozzle surface cleaning device according to claim 7, wherein the nozzle surface cleaning device is formed to be small.   The nozzle surface cleaning apparatus according to claim 7, further comprising a cleaning liquid suction unit configured to suck the cleaning liquid from the cleaning liquid recovery hole.   10. The cleaning liquid holding surface according to claim 1, wherein a downstream region in a moving direction relative to the nozzle surface is formed to converge toward a downstream side in the moving direction. The nozzle surface cleaning apparatus of description.   The nozzle surface cleaning device according to claim 10, wherein the cleaning liquid holding surface is formed to converge toward one side in a width direction.

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