JP2013184468A - Head replacement jig and head replacement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately reproduce a head position after replacing a head.SOLUTION: A jig frame 201 of a head replacement jig 200 is provided with a main scanning directional positioning reference that is a first positioning reference for determining the position of a main scanning directional reference surface of a head and two sub-scanning directional positioning references 203 that are second positioning references for determining a sub-scanning directional reference surface of the head, and has a first pressing means 207 which presses the main scanning directional reference surface of the head to the main scanning directional positioning reference and a second pressing means 208 which presses the sub-scanning directional reference surface of the head to the sub-scanning directional positioning references 203. The first pressing means 207 and the second pressing means 208 can independently press the head to the main scanning directional positioning reference and the sub-scanning directional positioning references 203.

Description

  The present invention relates to a head replacement jig and a head replacement method.

  As an image forming apparatus such as a printer, a facsimile, a copying machine, a plotter, or a complex machine of these, for example, a liquid discharge recording type image forming using a recording head composed of a liquid discharge head (droplet discharge head) that discharges ink droplets. Devices such as ink jet recording devices are known.

  By the way, in a head array in which a plurality of heads are arranged, it is preferable that only a defective head can be replaced. However, in order to replace the head, the head position before replacement is reproduced with high accuracy after replacement. You must be able to do it.

  Therefore, conventional head replacement uses a head replacement jig or the like to abut the head against the positioning reference of the jig (press it against the reference) or position the head against the position adjustment section of the jig. After the contact (pressed against the adjusting unit), the position is adjusted by the position adjusting unit and positioned.

  Further, as disclosed in Patent Document 1, with the recording head held by the head holding member, the head adjustment jig is fixed to the head holding member, and the biasing member of the head adjustment jig and the recording head In this state, the head adjustment jig is fixed to the head holding member, and the recording head to be removed is removed from the head holding member while maintaining the above state, and a new recording head is mounted on the head holding member. The method of fixing is then known.

  In this case, the urging member can be switched between a lock position for urging the head to be removed and an unlock position where the urging is released, and the urging member is located at the unlock position in the first step. Sometimes the step of temporarily fixing the position adjustment jig to the head holding member and the step of fixing the position adjustment jig in a state where the biasing member is in the locked position and the head moving member is in contact with the head are then performed. It is also known.

JP 2010-173242 A

  By the way, in the case of a multi-line head array composed of a plurality of heads, for example, in the main scanning direction (nozzle arrangement direction: direction orthogonal to the paper conveyance direction) and sub-scanning direction (direction orthogonal to the nozzle arrangement direction: paper conveyance direction). On the other hand, it is necessary to determine the position of the head. That is, the above-mentioned reference or adjustment unit (positioning reference) with which the head is abutted by pressing is required at least two places in the direction perpendicular to the head.

  In this case, if positioning is performed by simultaneously abutting the two directions of the head against the positioning reference, for example, when the positioning reference in the main scanning direction hits first, the friction at the contact portion suddenly increases at that point and has not yet hit. The head may not hit the positioning reference in the sub-scanning direction.

  On the other hand, when the positioning reference in the sub-scanning direction first hits, the positioning reference in the main scanning direction similarly becomes uncertain.

  As a result, there is a problem that the position of the head after the replacement of the head cannot be reproduced with high accuracy.

  The present invention has been made in view of the above problems, and an object of the present invention is to enable positioning and fixing of the head after replacement at an accurate position.

In order to solve the above problems, the head replacement jig according to the present invention is:
A head exchanging jig for exchanging the heads of a head array in which a plurality of nozzles for discharging droplets are arranged and a plurality of heads having a positioning reference with the nozzles are mounted on a base member,
A first positioning reference for determining a position of the head in the nozzle arrangement direction;
A second positioning reference for determining a position of the head in a direction orthogonal to the nozzle arrangement direction;
First pressing means for pressing the head against the first positioning reference;
Second pressing means for pressing the head against the second positioning reference;
The first pressing unit and the second pressing unit are configured to press the head against the first positioning reference and the second positioning reference independently.

  According to the present invention, the head after replacement can be positioned and fixed at an accurate position.

It is side explanatory drawing which shows an example of the image forming apparatus which has a head array which replaces a head with the head replacement jig concerning this invention. It is a plane explanatory drawing similarly. It is an external appearance perspective explanatory view showing an example of a head exchanged with a head exchange jig concerning a 1st embodiment of the present invention. It is bottom explanatory drawing seen from the nozzle surface side of the head. It is a perspective explanatory view of the head exchange jig concerning a 1st embodiment of the present invention. It is a plane explanatory drawing similarly. It is a section explanatory view in the state of pressing force given by the head exchange jig of the embodiment. It is the A section enlarged explanatory view of FIG. It is a section explanatory view of a pressing force release state similarly. FIG. 10 is an enlarged explanatory view of a B part in FIG. 9. FIG. 10 is a perspective explanatory view for explaining a head replacement method using the head replacement jig according to the embodiment. FIG. 12 is a perspective explanatory diagram for explaining a process following the process of FIG. 11. FIG. 13 is a perspective explanatory view for explaining a process following the process of FIG. 12. FIG. 14 is an explanatory perspective view for explaining a process following the process of FIG. 13. FIG. 15 is an explanatory perspective view for explaining a process following the process of FIG. 14. FIG. 16 is a perspective explanatory view for explaining a process following the process of FIG. 15. FIG. 17 is a perspective explanatory view for explaining a process following the process of FIG. 16. FIG. 18 is a perspective explanatory view for explaining a process following the process of FIG. 17. FIG. 19 is a perspective explanatory view for explaining a process following the process of FIG. 18. FIG. 20 is a perspective explanatory view for explaining a process following the process of FIG. 19. FIG. 21 is a perspective explanatory view for explaining a process following the process of FIG. 20. FIG. 22 is a perspective explanatory view for explaining a process following the process of FIG. 21. It is a perspective explanatory view showing an example of a head exchanged using a head exchange jig concerning a 2nd embodiment of the present invention. It is a perspective explanatory view of the head exchange jig of the embodiment. It is a plane explanatory drawing similarly. FIG. 6 is an explanatory cross-sectional view for explaining positioning and position adjustment in the main scanning direction in the head replacement jig of the same embodiment. It is bottom explanatory drawing seen through the array base from the nozzle surface side used for description of positioning in the sub scanning direction and position adjustment in the tilt direction in the head replacement jig of the same embodiment.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. First, an example of an image forming apparatus having a head array that performs head replacement with a head replacement jig according to the present invention will be described with reference to FIGS. FIG. 1 is an explanatory side view of the image forming apparatus, and FIG. In addition, an example of a head exchanged by the head exchange jig according to the present invention will be described with reference to FIGS. FIG. 3 is an external perspective view of the head, and FIG. 4 is a bottom view of the head viewed from the nozzle surface side (downward in FIG. 3).

  This image forming apparatus is an image forming apparatus using a line type recording head, and includes an apparatus main body 1, a paper feed tray 2 on which paper P is stacked and fed, and a paper discharge tray on which printed paper P is discharged and stacked. A paper tray 3, a transport unit 4 that transports the paper P from the paper feed tray 2 to the paper discharge tray 3, and a head unit 5 that constitutes a recording head that discharges and prints droplets on the paper P transported by the transport unit 4. The head maintenance device 6 that is a maintenance and recovery mechanism that performs maintenance and recovery of each recording head of the head unit 5 after completion of printing or at a required timing, and the cap member and wiper member (blade means) of the head maintenance device 6 are cleaned ( A cleaning device 7 is provided as a wiper cleaning means for cleaning.

  The apparatus main body 1 includes front and rear side plates and stays (not shown), and the sheets P stacked on the sheet feed tray 2 are fed one by one to the transport unit 4 by the separation roller 21 and the sheet feed roller 22. Is done.

  The transport unit 4 includes a transport drive roller 41A, a transport driven roller 41B, and an endless transport belt 43 wound around these rollers 41A and 41B. A plurality of suction holes (not shown) are formed on the surface of the transport belt 43, and a suction fan 44 that sucks the paper P is disposed below the transport belt 43. Further, conveyance guide rollers 42A and 42B are held by guides (not shown) on the conveyance driving roller 41A and conveyance driven roller 41B, respectively, and contact with the belt 43 by their own weight.

  The conveyance belt 43 rotates around when the conveyance driving roller 41A is rotated by a motor (not shown), and the paper P is sucked onto the conveyance belt 43 by the suction fan 44 and is conveyed by the rotation movement of the conveyance belt 43. The transport driven roller 41 </ b> B and the transport guide rollers 42 </ b> A and 42 </ b> B rotate following the transport belt 43.

  Above the transport unit 4, a head unit 5 composed of a plurality of heads that ejects droplets to be printed on the paper P is disposed so as to be movable (in this case, can be moved up and down). The head unit 5 rises to a position where the maintenance device 6 secures a space for entering the lower part of the head unit 5 during the maintenance and recovery operation (maintenance).

  The head unit 5 has a head array (recording) including four head rows 51A to 51D composed of a plurality of (in this example, five) heads 101 arranged in a row on an array base 52 that is a base member that is a head holding member. Head) 50.

  The head 101 has a plurality of nozzles for discharging droplets arranged in two rows on the nozzle surface. Then, one of the two nozzle rows of each head 101 of the head rows 51A and 51B discharges yellow (Y) droplets and the other ejects magenta (M) droplets. One nozzle row ejects cyan (C) droplets and the other ejects black (K) droplets. In other words, in the head unit 5, two head arrays 51 that discharge droplets of the same two colors are arranged side by side in the paper transport direction, and the nozzle array for one line corresponding to the paper width is configured by the two head arrays 51. It has a configuration. Here, the arrangement pitch of the nozzles in one row is set to 150 dpi, so that a formed image of one color is 150 dpi per line.

  The line configuration of each color is not limited to the above, and the arrangement of each color is not particularly limited. Further, the configuration of the head unit is not limited to this example. For example, two head units can be arranged side by side, and only one color can be assigned to one head, and the image resolution can be doubled as described above.

  Further, in the head unit 5, branch members (not shown) that supply ink to the respective heads 101 of the recording head 50 are arranged for each color, and a sub tank is arranged on the upstream side of the branch member, and a water head difference between the sub tank and the head. Thus, a negative pressure appropriate to hold the meniscus of the nozzle 102 of the head 101 is formed. Further, a replaceable main tank for storing ink is disposed on the upstream side of the sub tank.

  A conveyance guide unit 45 that discharges the paper P to the paper discharge tray 3 is disposed on the downstream side of the conveyance unit 4. The paper P conveyed by the conveyance guide unit 45 is discharged to the paper discharge tray 3. The paper discharge tray 3 includes a pair of side fences 31 that regulate the width direction of the paper P and an end fence 32 that regulates the front end of the paper P.

  A maintenance device 6 for maintaining the nozzle surface of the head 101 is disposed above the transport unit 4 and on the side of the head unit 5. The maintenance device 6 includes a cap 61 for capping the nozzle surface corresponding to each head 101 of the head arrays 51A to 51D, and a blade-like wiper member (wiper blade) not shown for wiping the nozzle surface corresponding to each head 101. And suction means (not shown) for sucking the inside of the caps 61 for one row. The maintenance device 6 restores the ejection performance of the head 101 by discharging the ink thickened from the nozzle by sucking with the suction means while the nozzle surface of the head 101 is sealed with the cap 61.

  The suction means 63 of the maintenance device 6, the flow path connecting the cap 61 and the suction means, and other pressure chambers are disposed outside the rear plate of the apparatus body 1 and may be connected using a route such as a tube. it can. Further, the inside of the head 101 may be pressurized by a pressurizing unit from the upstream side of the head 101 in place of or at the time of maintenance recovery.

  The maintenance device 6 is arranged so as to be slidable along the paper conveyance direction above the conveyance unit 4, and when the head is maintained, the head unit 5 is raised and then moved to the lower part of the head unit 5. During printing, the maintenance device 6 shown in FIG. Retreat to position.

  A cleaner device 7 for cleaning droplets (waste liquid) adhering to a cap 61 and a wiper blade (not shown) is disposed on the maintenance device 6. The cleaner device 7 is arranged so as to be vertically movable with respect to the sheet conveying surface by a cleaner moving means (not shown). When the maintenance device 6 that has completed the maintenance of the head 101 is retracted to the side of the head portion 5, the cleaner device 7 moves downward to clean the cap 61 and the wiper blade.

  The head 101 has a nozzle surface 103 on which a plurality of nozzles 102 for discharging droplets are arranged, and a head frame 104 that is a housing member that covers the outer peripheral surface. Here, the arrangement direction of the nozzles 102 is defined as the main scanning direction, and the direction orthogonal to the arrangement direction of the nozzles 102 is defined as the sub-scanning direction. The “main scanning direction” and “sub-scanning direction” are only used to define the direction, and the head 101 does not necessarily need to scan in both directions, and is configured to be fixed in one direction or both directions. There may be.

  The head frame 104 is formed with a main scanning direction reference surface 105 and a sub-scanning direction reference surface 106 that are accurately positioned with respect to the nozzles 102 (surfaces hatched in FIG. 3). The head frame 104 is provided with four fixing holes 107 for fixing the head 101, and is fixed to the array base (base member) 52 on which the head 101 is mounted with screws.

  Next, the head replacement jig according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 5 is an explanatory perspective view of the head replacement jig, and FIG.

  The head replacement jig 200 has a substantially U-shaped jig frame 201 when seen in a plan view.

  As shown in FIG. 6, the jig frame 201 includes a main scanning direction positioning reference 202 that is a first positioning reference for determining the position of the main scanning direction reference surface 105 in the nozzle arrangement direction in the head 101, and a nozzle arrangement in the head 101. Two sub-scanning direction positioning references 203 which are second positioning references for determining the position of the sub-scanning direction reference plane 106 in a direction orthogonal to the direction are provided.

  Further, a slider 205 is provided on the jig frame 201 on the side surface facing the main scanning direction positioning reference 202 so as to be movable in the vertical direction. Further, a slider 206 is provided on the jig frame 201 so as to be movable in the vertical direction on the side surface facing the positioning reference 203 in the sub-scanning direction. The slider 205 and the slider 206 are guided in the vertical direction by a pin member and a long hole into which the pin member is movably fitted.

  The slider 205 is attached with first pressing means 207 that presses the main scanning direction reference surface 105 of the head 101 against the main scanning direction positioning reference 202. The slider 206 is attached with second pressing means 208 that presses the sub-scanning direction reference surface 106 of the head 101 against the sub-scanning direction positioning reference 203.

  The slider 205 and the slider 206 can be moved in the direction of the arrow in FIG. 5, and the first pressing unit 207 and the second pressing unit 208 are independent of the head 101 in the main scanning direction positioning reference 202. And the sub-scanning direction positioning reference 203.

  The jig frame 201 is provided with fixing holes 209 for fixing the head replacement jig 200 at the four corners of the bottom, and the head replacement jig 200 can be fixed to the array base 52 with screws.

  Next, a pressing force application state and a pressing force release state by the head replacement jig of the embodiment will be described with reference to FIGS. 7 is an explanatory sectional view of the pressing force application state, FIG. 8 is an enlarged explanatory view of a portion A in FIG. 7, FIG. 9 is an explanatory sectional view of the pressing force released state, and FIG.

  First, as shown in FIGS. 7 and 8, the first pressing means 207 hits and contacts the end 111 on the opposite side of the main scanning direction reference surface 105 of the head 101 by pushing down the slider 205 in the direction of arrow a. Thus, the main scanning direction reference surface 105 is pressed against the main scanning direction positioning reference 202 of the head exchanging jig 200 by the elastic restoring force of the first pressing means 207, and the head 101 moves in the main scanning direction. The position is determined.

  Then, as shown in FIGS. 9 and 10, by pushing up the slider 205 in the direction of arrow b, the first pressing means 207 moves away from the end 111 on the opposite side of the main scanning direction reference surface 105 of the head 101, and the head The pressing force against 101 is released.

  The array base 52 is provided with a hole 52a into which the first pressing means 207 enters. Further, although not shown here, a hole 52a into which the second pressing means 208 enters is also provided.

  Next, as shown in FIG. 7, the second pressing unit 208 is pushed down to contact the end of the head 101 opposite to the reference surface 106 in the sub-scanning direction by the second pressing unit 208. By the elastic restoring force 208, the head 101 has the sub-scanning direction reference surface 106 pressed against the sub-scanning direction positioning reference 203 of the head replacement jig 200 (the abutment), and the position of the head 101 is determined.

  Then, as shown in FIG. 9, by pushing up the slider 206, the second pressing means 208 moves away from the end of the head 101 opposite to the reference surface 106 in the sub-scanning direction, and the pressing force on the head 101 is released. .

  Here, the pressing force by the first pressing means 207 is set smaller than the pressing force of the second pressing means 208. Specifically, the first and second pressing means 207 and 208 are formed of spring members, the plate thickness is the same, and the widths are made different so that the pressing force has a magnitude relationship.

  As described above, the first pressing unit 207 and the second pressing unit 208 that press the head 101 are provided independently with respect to the orthogonal main scanning direction positioning reference 202 and sub-scanning direction positioning reference 203, thereby pressing the head 101. The application of the force and the release of the pressing force can be performed separately by the first pressing unit 207 and the second pressing unit 208.

  The pressing force in the main scanning direction by the first pressing means 207 is set smaller than the pressing force in the sub-scanning direction by the second pressing means 208.

  Therefore, the main scanning direction reference surface of the head 101 can be reliably abutted against the main scanning direction positioning reference 202 by first applying the pressing force in the main scanning direction by the first pressing means 207 having a small pressing force.

  At this time, since the pressing force in the sub-scanning direction by the second pressing means 208 is not applied, there is no occurrence of catching due to the frictional force in the orthogonal direction that hinders the head 101 moving in the main scanning direction.

  Thereafter, a pressing force in the sub-scanning direction by the second pressing means 208 having a large pressing force can be applied, and the head 101 can be reliably abutted against the sub-scanning direction positioning reference 203.

  At this time, the pressing force in the main scanning direction by the first pressing means 207 is applied, but since the pressing force by the second pressing means 208 is larger, the friction in the head moving direction generated by the pressing force in the main scanning direction. It can be pressed with a pressing force larger than the force, and reliable abutment without catching can be performed.

  In other words, the head to be replaced can be accurately positioned and fixed by ensuring that the positioning reference surface of the head 101 abuts against the positioning reference.

  Next, a head replacement method using the head replacement jig according to the embodiment will be described with reference to FIGS. 11 to 12 are perspective explanatory views for explaining the head replacement method.

  First, as shown in FIG. 11, an existing head 101 to be replaced (hereinafter referred to as “head 101 </ b> A”) is fixed to the array base 52 with four screws 120.

  Therefore, as shown in FIG. 12, the head replacement jig 200 in which the sliders 205 and 206 are moved in the direction of the arrow with respect to the head 101A, and the first pressing means 207 and the second pressing means 208 are released from the pressing force. Is set on the array base 52 from above the head 101A.

  Next, as shown in FIG. 13, the head replacement jig 200 is screwed into the screw holes 52 b provided in the array base 52 through screws 220 into the fixing holes 209 provided in the four corners of the bottom of the head replacement jig 200, and the head replacement jig 200 is inserted into the array base 52. Temporarily fix to. Temporary fixing refers to a state in which the head replacement jig 200 can move in the horizontal direction by the backlash of the fixing hole 209 with respect to the array base 52.

  Next, as shown in FIG. 14, the slider 205 of the head replacement jig 200 is pushed down, the head 101A is pushed in the main scanning direction by the first pressing means 207, and the main scanning direction reference 202 of the head 101A is set to the head replacement jig 200. It abuts against the main scanning direction positioning reference 207. Thereby, the position of the head replacement jig 200 in the main scanning direction is positioned by the head 101A.

  At this time, as described above, the pressing force in the main scanning direction by the first pressing means 207 is set smaller than the pressing force in the sub-scanning direction by the second pressing means 208. Therefore, the main scanning direction reference surface of the head 101 </ b> A is reliably abutted against the main scanning direction positioning reference 202 by independently applying the pressing force in the main scanning direction by the first pressing means 207 having a small pressing force.

  Thus, the abutment can be surely performed without any trouble such as a collision. That is, since the pressing force in the sub-scanning direction by the second pressing means 208 is not applied, the head frame 104 is pressed against the sub-scanning direction positioning reference, and the head replacement jig 200 does not move in the main scanning direction. No malfunction occurs.

  Next, as shown in FIG. 15, the slider 206 of the head replacement jig 200 is pushed down, the head 101A is pushed in the sub-scanning direction by the second pressing means 208, and the sub-scanning direction reference 202 of the head 101A is used as the head replacement jig 200. It is abutted against the positioning reference 208 in the sub-scanning direction. Thereby, the position of the head replacement jig 200 in the sub-scanning direction is positioned by the head 101A.

  At this time, as described above, the pressing force in the sub-scanning direction by the second pressing means 208 is set larger than the pressing force in the main scanning direction by the first pressing means 207. Therefore, after the abutting with respect to the positioning reference 207 in the main scanning direction is reliably performed, the abutting without a catch or the like is performed by pressing in the sub scanning direction with a pressing force larger than the pressing force in the main scanning direction. Accurate positioning in the sub-scanning direction is possible.

  As described above, the head replacement jig 200 is accurately positioned with respect to the pre-replacement head 101A in the main scanning direction and the sub-scanning direction. Therefore, the four screws 220 temporarily fixed in this state are finally tightened. Then, the head replacement jig 200 is completely fixed to the array base 52.

  Next, as shown in FIG. 16, four screws 120 fixing the head 101A before replacement to the array base 52 are removed, and the head 101A is removed upward.

  Then, as shown in FIG. 17, the sliders 205 and 206 of the head replacement jig 200 are pushed upward to bring the first pressing means 207 and the second pressing means 208 to the positions where the pressing force is released.

  The pressing force may be released after the head replacement jig 200 before removing the head 101A is completely fixed to the array base 52. In short, it may be in the released state before setting a new head. .

  Next, as shown in FIG. 18, a new head 101 (this will be referred to as “head 101B”) is placed on the array base 52, and temporarily fixed with screws 120 as shown in FIG. The temporary fixing means that the head 101B is fixed to the array base 52 to which the head 101B is fixed in a state in which the head 101B can move in the horizontal direction by the backlash between the fixing hole 109 of the head 101B and the screw 120. .

  Next, as shown in FIG. 20, the slider 205 of the head replacement jig 200 is pushed down, the head 101B is pressed in the main scanning direction by the first pressing means 207, and the main scanning direction reference surface 105 of the head 101B is moved to the head replacement jig 200. The main scanning direction positioning reference 202. Thereby, the main scanning direction position of the head 101B is positioned.

  At this time, as described above, the pressing force in the main scanning direction by the first pressing means 207 is set smaller than the pressing force in the sub-scanning direction by the second pressing means 208. Therefore, the main scanning direction reference surface 105 of the head 101B is reliably abutted against the main scanning direction positioning reference 202 by independently applying the pressing force in the main scanning direction by the first pressing means 207 having a small pressing force.

  Thus, the abutment can be surely performed without any trouble such as a collision. In other words, since the pressing force in the sub-scanning direction by the second pressing unit 208 is not applied, there is a problem that the head frame 104 is pressed against the sub-scanning direction positioning reference 208 and the head 101B does not move in the main scanning direction. It does not occur, and the abutment can be performed reliably.

  Next, as shown in FIG. 21, the slider 206 of the head replacement jig 200 is pushed down, the head 101B is pressed in the sub-scanning direction by the second pressing means 208, and the sub-scanning direction reference surface 106 of the head 101B is moved to the head replacement jig. It abuts on the 200 sub-scanning direction positioning reference 203. Thereby, the sub-scanning direction position of the head 101B is positioned.

  At this time, as described above, the pressing force in the sub-scanning direction by the second pressing means 208 is set larger than the pressing force in the main scanning direction by the first pressing means 207. Therefore, after the abutting with respect to the positioning reference 207 in the main scanning direction is reliably performed, the abutting without a catch or the like is performed by pressing in the sub scanning direction with a pressing force larger than the pressing force in the main scanning direction. Accurate positioning in the sub-scanning direction is possible.

  As described above, the new head 101B is positioned with respect to the main scanning direction positioning reference 202 and the sub scanning direction positioning reference 203 of the head replacement jig 200.

  Therefore, the four screws 120 that temporarily fixed the head 101B in a state where the head 101B is pressed against the head replacement jig 200B by the first pressing means 207 and the second pressing means 208 are finally tightened, and the head 101B is fixed. It is completely fixed to the array base 52.

  At this time, the head replacement jig 200 abuts the main scanning direction positioning reference 202 and the main scanning direction reference surface 105 against the pre-replacement head 101A, and the sub-scanning direction positioning reference 203 and the sub-scanning direction reference surface 106. Since it is fixed to the array base 52 while being positioned by abutment, the newly replaced head 101B is positioned and fixed at the same position as the pre-replacement head 101A, and the positioning accuracy is reproduced.

  Thereafter, as shown in FIG. 22, four screws 220 that have fixed the head replacement jig 200 to the array base 52 are removed, and the head replacement jig 200 is removed from the array base 52 upward.

  Thus, the head replacement operation is completed.

  Next, an example of a head to be replaced using the head replacement jig according to the second embodiment of the present invention will be described with reference to FIG. FIG. 23 is an external perspective view of the head.

  Also in the head frame 104 of the head 101 of this embodiment, a main scanning direction reference surface 105 and sub-scanning direction reference surfaces 106a and 106b that are accurately positioned with respect to the nozzle 102 are formed.

  Here, the main scanning direction reference surface 105 is formed on one side surface in the sub-scanning direction at a substantially central portion in the longitudinal direction in a direction perpendicular to the nozzle arrangement direction. Further, the sub-scanning direction reference surfaces 106a and 106b are formed on one side surface in the sub-scanning direction and at both ends in the longitudinal direction.

  The head frame 104 is provided with two fixing holes 107 for fixing the head 101, and is fixed to the array base (base member) 52 on which the head 101 is mounted with screws.

  In this embodiment, the inclination of the rotation direction of the head 101 in the horizontal plane is defined as “inclination”.

  Next, the head replacement jig of this embodiment will be described with reference to FIGS. FIG. 24 is an explanatory perspective view of the head replacement jig, and FIG. 25 is an explanatory plan view of the same. FIG. 24 shows a part of the jig frame in a transparent state.

  The head replacement jig 300 has a substantially box-shaped jig frame 301.

  As shown in FIG. 25, the jig frame 301 includes a main scanning direction position adjusting unit 302 serving as a first positioning reference for determining the position of the main scanning direction reference surface 105 that is an end surface of the head 101 in the nozzle arrangement direction, and the head. A sub-scanning direction positioning reference 303 and a sub-scanning direction position adjusting unit 313 are provided as second positioning references for determining the position of the sub-scanning direction reference surface 106 in the direction orthogonal to the nozzle arrangement direction in 101.

  In addition, a slider 305 is provided on the jig frame 301 so as to be movable in the vertical direction on the side surface that intersects the side surface provided with the main scanning direction position adjusting unit 302 and faces the end surface of the head 101 in the nozzle arrangement direction. . In addition, a slider 306 is provided on the jig frame 301 so as to be movable in the vertical direction on the side surface facing the sub-scanning direction positioning reference 303 and the sub-scanning direction position adjusting unit 313. These sliders 305 and 306 are guided in the vertical direction by a pin member and a long hole into which the pin member is movably fitted.

  The slider 305 is attached with first pressing means 307 that presses the main scanning direction reference surface 105 of the head 101 against the main scanning direction position adjustment unit 302. Further, the slider 306 is provided with second pressing means 308 that presses the sub-scanning direction reference surface 106 of the head 101 against the sub-scanning direction positioning reference 203 and the sub-scanning direction position adjustment unit 313.

  The slider 305 and the slider 306 can be moved independently. The first pressing unit 307 and the second pressing unit 308 independently operate the head 101 in the main scanning direction position adjusting unit 302 and the sub scanning direction. It can be pressed against the positioning reference 303 and the sub-scanning direction position adjustment unit 313.

  The jig frame 301 is provided with fixing holes 309 for fixing the head replacement jig 300 at four positions on the bottom, and the head replacement jig 300 can be fixed to the array base 52 with screws.

  Next, positioning and position adjustment in the main scanning direction in the head replacement jig of the embodiment will be described with reference to FIG. FIG. 26 is a cross-sectional explanatory view for explaining the same.

  First, when the slider 305 is pushed down, the first pressing unit 307 comes into contact with the end portion of the head 101 in the main scanning direction, and a pressing force is applied to the head 101, and the main scanning direction reference surface 105 of the head 101 is replaced with a head. It abuts against the main scanning direction position adjustment unit 302 of the jig 300.

  Here, the main scanning direction position adjustment unit 302 employs a taper pin method, has a taper pin 322 having a taper part 321 against which the main scanning direction reference surface 105 of the head 101 abuts, and is arranged above the taper pin 322. The screw part 323 is formed and is rotatably attached to the jig frame 301, and can be moved up and down with respect to the jig frame 301 by rotating the rotating part 324 provided at the uppermost part.

  Accordingly, by moving the taper pin 322 up and down, the position of the reference surface 105 in the main scanning direction of the head 101 that is in contact with the tapered portion 321 can be adjusted in the main scanning direction (left and right direction in the figure). That is, the main scanning direction position adjustment unit 302 can adjust the position of the head 101 in the main scanning direction.

  Next, positioning in the sub-scanning direction and position adjustment in the tilt direction in the head replacement jig of the embodiment will be described with reference to FIG. FIG. 27 is a bottom explanatory view seen through the array base from the nozzle surface side for the same explanation.

  First, when the slider 306 is pushed down, the second pressing means 308 comes into contact with the end portion of the head 101 in the sub-scanning direction, a pressing force is applied to the head 101, and one of the sub-scanning direction reference surfaces 106a of the head 101 is moved. The head replacement jig 300 abuts against the positioning reference 303 in the sub-scanning direction.

  On the other hand, the sub-scanning direction position adjustment unit 313 adopts a taper pin method similarly to the main scanning direction position adjustment unit 302, and the other sub-scanning direction reference of the head 101 as shown in FIG. A taper pin 332 having a taper portion 331 against which the surface 106b abuts is formed. A screw portion 333 is formed on the upper portion of the taper pin 332 and is rotatably attached to the jig frame 301, and a rotation portion 334 provided at the uppermost portion. Can be moved up and down with respect to the jig frame 301.

  Accordingly, by moving the taper pin 332 up and down, the position of the reference surface 106b in the sub-scanning direction of the head 101 that is in contact with the taper portion 331 can be adjusted, and the head 101 is moved by the sub-scanning direction position adjusting unit 313. Since it can be rotated in the horizontal direction with respect to one sub-scanning direction reference 106a, the tilt of the head 101 can be adjusted.

  That is, the sub-scanning direction position of the head 101 to be replaced is positioned by the sub-scanning positioning reference 303, and the tilt of the head 101 can be adjusted by the sub-scanning direction position adjustment unit 313.

  The process of the head replacement method performed using the head replacement jig 300 according to the present embodiment is the same process as the head replacement method performed using the head replacement jig 200 according to the first embodiment.

  That is, the taper portions 321 and 331 of the main scanning direction position adjustment unit 302 and the sub-scanning direction position adjustment unit 313 are set to neutral (center position of the adjustment range of the taper pins 322 and 332), and the head is replaced with the head before replacement. The jig 300 is positioned and fixed. At this time, the order in which the pressing force is applied is the same as described in the first embodiment.

  Then, the head before replacement is removed, the pressing force is released, and a new head is set on the positioned head replacement jig 300 and temporarily fixed, and the pressing force in the main scanning direction is applied as in the first embodiment. Then, a pressing force in the sub-scanning direction is applied to position the head.

  After that, in this embodiment, when the head is abutted and positioned, an image is output, the image has defects such as black streaks and white streaks, and if the head position needs to be finely adjusted, The main scanning direction position adjustment unit 302 and the sub scanning direction position adjustment unit 313 of the head replacement jig 300 adjust the position and inclination of the newly replaced head in the main scanning direction.

  That is, even if the positioning reference surface of the head and the position of the nozzle are accurately aligned, they are not “0” but are actually aligned with some variation. For this reason, positional deviation may occur with respect to the target mounting position of the head due to the variation between the head before replacement and the head after replacement, and the droplets ejected from the head are not always perpendicular to the nozzle surface. There is a case in which a phenomenon of discharge bending in which the ink is discharged at an incline occurs. As a result, even if the head is mounted accurately at the target position, streaks such as those described above may occur at the connecting portion of images between adjacent heads, and position adjustment can be performed to eliminate this. I am doing so.

  In this embodiment, the position of the newly replaced head in the main scanning direction can be adjusted by the main scanning direction position adjusting unit 302, and the inclination can be adjusted by the sub-scanning direction position adjusting unit 313. Since it is positioned by abutment according to the direction positioning reference 303, it cannot be adjusted. However, this can be dealt with by correcting the droplet discharge timing.

  By performing head replacement using the head replacement jig described in the first and second embodiments, it is not necessary to provide many highly accurate positioning references on the base member. That is, if 10 heads are mounted, the reference in the main scanning direction and the sub-scanning direction is usually required for each head, so at least 20 reference members are required on the base member. However, in these embodiments, it is possible to replace all the heads if there is an exchange jig provided with two or three highly accurate positioning references.

  In terms of work efficiency in head replacement work, it is preferable to provide a large number of standards on the base member. However, actual head replacement is mostly performed for replacement of defective heads, and is replaced in units of one head. In many cases, the decrease in work efficiency is not a big problem. Also, the difficulty of matching with other heads that can only be achieved by exchanging one head can be adjusted to an optimum state in the second embodiment.

  In the present application, the “paper” is not limited to paper, but includes OHP, cloth, glass, a substrate, etc., and means a material to which ink droplets or other liquids can be attached. , Recording media, recording paper, recording paper, and the like. In addition, image formation, recording, printing, printing, and printing are all synonymous.

  The “image forming apparatus” means an apparatus that forms an image by discharging liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, etc. “Formation” means not only giving an image having a meaning such as a character or a figure to a medium but also giving an image having no meaning such as a pattern to the medium (simply causing a droplet to land on the medium). ) Also means.

  The “ink” is not limited to an ink unless otherwise specified, but includes any liquid that can form an image, such as a recording liquid, a fixing processing liquid, or a liquid. Used generically, for example, includes DNA samples, resists, pattern materials, resins, and the like.

  In addition, the “image” is not limited to a planar image, and includes an image given to a three-dimensionally formed image and an image formed by three-dimensionally modeling a solid itself.

  Further, the image forming apparatus includes both a serial type image forming apparatus and a line type image forming apparatus, unless otherwise limited.

4 Conveying section 5 Head section 52 Array base (base member)
101 Head 105 Main scanning direction reference plane 106, 106a, 106b Sub scanning direction reference plane 200, 300 Head replacement jig 201, 301 Jig frame 202 Main scanning direction positioning reference 203 Sub scanning direction positioning reference 205, 206 Slider 207, 307 First pressing means 208, 308 Second pressing means 302 Main scanning direction adjustment section 303 Sub scanning direction positioning reference 313 Sub scanning direction adjustment section

Claims (4)

A head exchanging jig for exchanging the heads of a head array in which a plurality of nozzles for discharging droplets are arranged and a plurality of heads having a positioning reference with the nozzles are mounted on a base member,
A first positioning reference for determining a position of the head in the nozzle arrangement direction;
A second positioning reference for determining a position of the head in a direction orthogonal to the nozzle arrangement direction;
First pressing means for pressing the head against the first positioning reference;
Second pressing means for pressing the head against the second positioning reference;
The head replacement jig, wherein the first pressing means and the second pressing means independently press the head against the first positioning reference and the second positioning reference. The pressing force of the first pressing means is different from the pressing force of the second pressing means,
2. The head replacement jig according to claim 1, wherein the pressing force of the first pressing means is smaller than the pressing force of the second pressing means.   The head replacement jig according to claim 1, further comprising an adjusting unit that adjusts a position of at least one of the first positioning reference and the second positioning reference. A head replacement method for performing head replacement using the head replacement jig according to claim 2,
Temporarily fixing the head replacement jig to the base member in a state where the pressing force by the first pressing means and the second pressing means of the head replacement jig is released;
After the head is pressed against the first positioning reference with the first pressing means having a small pressing force, the head is pressed against the second positioning reference with the second pressing means having a large pressing force, and the head replacement jig Fixing to the base member;
Releasing the pressing force of the first pressing means and the second pressing means and replacing the head;
After the replaced head is pressed against the first positioning reference by the first pressing means, the replaced head is pressed against the second positioning reference by the second pressing means, and the replaced head is moved to the base. And a step of fixing to a member.

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