JP2008213385A - Image forming apparatus - Google Patents

Abstract

A recording head, a conveyor belt, and a maintenance / recovery mechanism cannot be positioned with high accuracy with a simple configuration.
One end portion of a guide rod and a maintenance / recovery mechanism are fixed, and a first fixing member and a guide belt of the maintenance / recovery mechanism are fixed to the guide rod by positioning with respect to the guide rod and a conveyor belt. One end of the shaft 36a of the transport roller 36 and the maintenance / recovery mechanism 38 are fixed, and a second fixing member 112 is provided for positioning and fixing the maintenance / recovery mechanism 38 with respect to the transport belt 35.
[Selection] Figure 6

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus including a recording head, a conveyance belt, and a maintenance / recovery mechanism.

  2. Related Art As an image forming apparatus such as a printer, a facsimile machine, a copying apparatus, and a composite machine of these, for example, an ink jet recording apparatus is known as an image forming apparatus of a liquid discharge recording method using a recording head that discharges a recording liquid droplet. . This ink jet recording apparatus means a recording liquid (for example, ink droplets) that is transported from the nozzle of the recording head (not limited to paper, including OHP, etc., meaning that ink droplets, other liquids, etc. can adhere to the paper. The recording medium is also called a recording medium or recording medium, recording paper, recording paper, etc.) to form an image (recording, printing, printing, and printing are also used synonymously). There is a serial type in which the recording head moves in the main scanning direction.

In such an image forming apparatus, for example, in Patent Document 1, the distance between the head and the maintenance unit (maintenance / recovery mechanism) is adjusted by a mechanism that adjusts the distance between the head and the paper. An adjustment mechanism for moving the belt roller side portion of the belt chassis and the driven roller side portion of the belt chassis linked to the belt chassis in a direction approaching / separating from the head surface. In the case of adjusting the gap, in Patent Document 3, the driven shaft of the conveyor belt that is driven to swing up and down in order to open and close the head cap is brought into direct contact with the height reference portion or through a spacer. The gap between the line head and the conveyor belt is adjusted depending on whether or not, and in Patent Document 4, the hole is formed in the side plate. That to be able to take out a recovery mechanism in the main scanning direction side are described, respectively.
JP 2001-353860 A Japanese Patent Laying-Open No. 2005-306032 JP 2003-94744 A JP 2006-76053 A

  In the above-described liquid ejection type image forming apparatus, the number of nozzles and the number of colors tend to increase in order to achieve high speed and high density. For this reason, the recording head becomes long and transports other units such as paper. It is difficult to maintain the positional relationship with the conveying means that performs the maintenance and the maintenance and recovery mechanism that performs the maintenance and recovery of the recording head. If the gap between the recording head and the paper conveyed by the conveying means fluctuates, the liquid droplet landing position shifts and the image quality deteriorates. Also, if the positional relationship with the maintenance / recovery mechanism deviates, capping by the cap member for capping the nozzle surface of the recording head is insufficient, or wiping by the wiper member for wiping the nozzle surface of the recording head is insufficient. This causes problems such as failure to reliably maintain and recover the performance of the recording head.

  The above-described patent documents 1 to 3 adjust the gap between the head and the paper or the conveyance belt on the premise of the positional relationship between the properly positioned recording head and the conveyance belt. The positional relationship of the conveyor belt cannot be accurately positioned before adjustment. Further, the one described in Patent Document 4 is a detachable maintenance / recovery mechanism, but does not describe a configuration for accurately positioning the positional relationship with the recording head.

  In addition, in inkjet printers and inkjet multifunction devices that are used not only for personal use but also for business use, high precision and high durability are required. Is required to be easily assembled with high precision positioning.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to enable a recording head, a conveyance belt, and a maintenance / recovery mechanism to be positioned with high accuracy with a simple configuration.

  In order to solve the above problems, an image forming apparatus according to the present invention is a transport unit including a transport belt that transports a recording medium, a carriage on which a recording head that discharges droplets is mounted, and a carriage movement reference. A guide rod, a recording head maintenance / recovery mechanism, one end of the guide rod and a maintenance / recovery mechanism are fixed, one first fixing member for determining the position of the maintenance / recovery mechanism relative to the guide rod, a maintenance / recovery mechanism, and a conveyor belt And a second fixing member that determines the position of the maintenance / recovery mechanism with respect to the conveyor belt.

  Here, it is preferable that the maintenance / recovery mechanism is connected to the first fixing member at one point and is connected to the second fixing member at two points. In this case, the connecting portion between the maintenance / recovery mechanism and the first fixing member is positioned in the vertical direction of the center of gravity of the maintenance / recovery mechanism, or the connecting portion between the maintenance / recovery mechanism and the first fixing member is It is preferable to be positioned in the vertical direction of the head maintenance portion of the maintenance and recovery mechanism.

  Moreover, it is preferable that the conveyance belt and the maintenance / recovery mechanism are positioned in parallel at the two connecting portions of the maintenance / recovery mechanism and the second fixing member.

  Further, it is preferable that at least one of the first fixing member and the maintenance / recovery mechanism is provided with a restricting means for restricting the rotation of the maintenance / recovery mechanism. In this case, it is preferable that the restricting means is provided outside the maintenance section of the maintenance / recovery mechanism.

  The first fixing member is preferably detachable.

  Further, the first fixing member may have a fixing portion for fixing a linear scale for detecting the carriage position. In this case, it is preferable that the linear scale is fixed to the first fixing member so as to be perpendicular to the conveyor belt surface. Moreover, it can be set as the structure which provided the 3rd fixing member which fixes a guide rod and a linear scale in the other end part side of a guide rod. In this case, the linear scale is preferably fixed to the third fixing member so as to be positioned perpendicular to the transport belt surface.

  Moreover, it is preferable that the maintenance / recovery mechanism is detachably mounted.

  According to the image forming apparatus of the present invention, a transport unit including a transport belt that transports a recording medium, a carriage on which a recording head that discharges droplets is mounted, a guide rod that serves as a carriage movement reference, and a recording head The maintenance / recovery mechanism, one end of the guide rod and the maintenance / recovery mechanism are fixed, one first fixing member for determining the position of the maintenance / recovery mechanism relative to the guide rod, the maintenance / recovery mechanism and the conveyor belt are fixed, and the conveyor belt With this configuration, the recording head, the maintenance / recovery mechanism, and the conveyance belt can be easily positioned and fixed with high accuracy.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. An example of an image forming apparatus to which the present invention is applied will be described with reference to FIGS. 1 is an overall configuration diagram of the image forming apparatus, FIG. 2 is an explanatory diagram on the right side of FIG. 1, FIG. 3 is an explanatory perspective view of a recording unit of the apparatus, and FIG. 4 is a bottom view of a carriage of the apparatus. FIG.

  The image forming apparatus is a copying apparatus. The apparatus main body 1 includes an image reading unit 2 such as a scanner for reading an original image, a recording unit 3 for forming an image on a recording medium (hereinafter referred to as “paper”) P, and a recording. The unit 3 includes a paper feed cassette unit 4 that feeds the paper P. Then, the paper P stored in the paper feed cassette unit 4 is separated and fed one by one by the paper feed roller 5 and the separation pad, and conveyed to the printing unit 10 through the conveyance path 7 to record a required image. The paper P on which the image is formed passes through the paper discharge path 8 and is discharged and stacked on the paper discharge stack unit 9.

  Here, as shown in FIG. 3, the printing unit 10 holds a carriage 23 by a carriage guide (guide rod) 21 and a guide stay (not shown) so as to be movable in the main scanning direction, and a driving pulley by a main scanning motor 27. The moving scanning is performed in the main scanning direction via a timing belt 30 spanned between 28 and the driven pulley 29.

  On the carriage 23, a recording head 24k composed of a liquid ejection head for ejecting black (K) ink and 1 each for ejecting cyan (C) ink, magenta (M) ink, and yellow (Y) ink, respectively. The recording heads 24c, 24m, and 24y (which are referred to as “recording head 24” when they are not distinguished or collectively referred to) are mounted.

  As shown in FIG. 4, each recording head 24 has two nozzle rows 32 in which a plurality of nozzles 31 for discharging droplets are arranged in a row, and the nozzle rows 32 are arranged in the main scanning direction (of the carriage 23). The carriage 23 is mounted with a surface (referred to as a nozzle nozzle surface 31a) on which the nozzle 31 is formed facing downward so as to be in a direction orthogonal to the movement direction. Each recording head 24 is supplied with ink of a required color from an ink cartridge 26.

  The recording head 24 uses a piezoelectric element as a pressure generating means (actuator means) for pressurizing the ink in the ink flow path (pressure generation chamber) to deform the vibration plate that forms the wall surface of the ink flow path. A so-called piezo type that discharges ink droplets by changing the volume in the flow channel, or discharges ink droplets with a pressure generated by heating the ink in the ink flow channel using a heating resistor to generate bubbles. The so-called thermal type, the diaphragm that forms the wall surface of the ink flow path and the electrode are placed opposite to each other, and the diaphragm is deformed by the electrostatic force generated between the vibration plate and the electrode, thereby the ink flow path inner volume It is possible to use an electrostatic type or the like that discharges ink droplets by changing the above.

  An endless transport belt 35 that transports the paper P by electrostatic adsorption or the like is disposed below the carriage 23. The conveyor belt 35 is wound between the driving roller 36 and the driven roller 37 and moves around, thereby conveying the paper P in a direction orthogonal to the main scanning direction.

  Further, as shown in FIGS. 2 and 3, a maintenance / recovery mechanism (device) 38 for maintaining and recovering the nozzle state of the recording head 24 is disposed in the non-printing area on one side of the carriage 23 in the scanning direction. An empty discharge receiving member 39 for empty discharge is disposed in the non-printing area on the other side in the scanning direction.

  The maintenance / recovery mechanism 38 wipes a plurality of cap members 41 (a suction cap 41a and three moisturizing caps 42b) for capping each nozzle surface 31a of the recording head 24 and the nozzle surface 31a of the recording head 24 in the frame 38A. For this purpose, a wiper blade 42 as a wiping member and an idle discharge receiver 43 are arranged. A suction pump 45 using a tube pump is connected to the suction cap 41a, and is discharged from the suction pump 45 through a discharge tube 46 to a waste liquid container 40 containing waste ink disposed on the lower side. The empty discharge receiving member 39 has four openings 39a.

Accordingly, a first embodiment of the present invention applied to this image forming apparatus will be described with reference to FIGS. 5 is a front explanatory view of the printing unit of the embodiment, and FIG.
The carriage 23 is slidably guided, and a guide rod 21 serving as a movement reference for the carriage 23 is horizontally supported between the left and right (left and right in the state of FIG. 5) outer plates 101A and 101B. The shaft 36a of the conveyance roller 36 around which the conveyance belt 35 is wound is horizontally supported by the left and right inner plates 102A and 102B and is rotatably supported.

  Here, one end of the guide rod 21 is fixedly held by the first fixing member 111. The first fixing member 111 is provided with a hole portion 122 into which a connecting portion (also referred to as a connecting portion or a fixing portion) 121 of the maintenance and recovery mechanism 38 (actually its frame) is engaged. The hole portion 122 of the first fixing member 111 and the connecting portion 121 of the maintenance / recovery mechanism 38 are provided at predetermined positions based on the position of the maintenance / recovery mechanism 38 relative to the guide rod 21. Further, the first fixing member 111 is fixed to the left outer plate 101A after positioning by a fastener such as a screw.

  On the other hand, one end portion of the shaft 36 a of the conveyance roller 36 around which the conveyance belt 35 is wound is rotatably supported by the second fixing member 112. The second fixing member 112 is provided with two holes 133 into which the connecting portions 131 and 132 of the maintenance and recovery mechanism 38 are engaged. The holes 133 and 133 of the second fixing member 112 and the connecting portions 131 and 132 of the maintenance / recovery mechanism 38 are provided at predetermined positions based on the position of the maintenance / recovery mechanism 38 with respect to the transport belt 35. The second fixing member 112 is fixed to the left inner plate 101A with a fastener such as a screw after the conveyance belt 35 is positioned with respect to the carriage 23 (guide rod 21).

  Accordingly, the maintenance / recovery mechanism 38 is connected and fixed to the first fixing member 111 by the connecting portion 121, and is also connected to the second fixing member 112 by the connecting portions 131 and 132 and fixed. The positional relationship between the three units of the recovery mechanism 38, the guide rod 21 serving as a carriage movement reference, and the conveyance belt 35 that conveys the recording medium is defined.

  The maintenance / recovery mechanism 38 is positioned by the first fixing member 111 and the second fixing member 112 and then fixed to the left outer plate 101A by a fastener such as a screw.

  In this way, the one end portion of the guide rod and the maintenance / recovery mechanism are fixed, one first fixing member that determines the position of the maintenance / recovery mechanism with respect to the guide rod, the maintenance / recovery mechanism and the conveyor belt are fixed, and the maintenance with respect to the conveyor belt is maintained. By having one second fixing member that determines the position of the recovery mechanism, the maintenance / recovery mechanism, the guide rod, and the conveyor belt can be easily positioned and fixed with high accuracy, thereby improving the print quality. As a result, it is possible to form a high-quality image, and it is possible to improve durability because only positioning is performed by a fixing member.

  In the above description, a connecting portion as a projection made of a pin member is provided on the maintenance / recovery mechanism 38 side, and a hole for engaging the connecting portion is provided in the first and second fixing members 111 and 112. (This also applies to the following description.)

  In this embodiment, after the maintenance / recovery mechanism 35 is fixed to the left outer plate 101A, the position of the connecting portion 121 of the maintenance / recovery mechanism 35 is fixed even if the first fixing member 111 is removed. It can be restored to the same position. Thereby, a 1st fixing member and a guide rod can be attached or detached. Accordingly, carriage replacement and the like can be easily performed.

  Here, as shown in FIG. 7, the fixing portion of the maintenance / recovery mechanism 38 is fixed at one point to the first fixing member 111 shared with the guide rod 21 (the connecting portion 121 and the corresponding hole portion). 122), and two fixing portions (connecting portions 131 and 132 and corresponding hole portions 133) are provided between the second fixing member 112 shared with the conveyance belt 35.

  Thus, by positioning the maintenance / recovery mechanism 38 between the transport belt 35 and the guide rod 21 at three points, the positional relationship between the surface of the transport belt 35 and the maintenance / recovery mechanism 38 and the recording based on the guide rod 21 are recorded. The positional relationship between the nozzle surface 31a of the head 24 and the cap member 41 and the wiper member 42 of the maintenance / recovery mechanism 38 can be determined with high accuracy.

Next, examples of different arrangement positions of one fixing portion when the maintenance / recovery mechanism 38 is fixed to the first fixing member 111 by one fixing portion will be described with reference to FIGS. 8 and 9. To do.
First, in the first example shown in FIG. 8, one fixing portion is provided in the region 142 in the vertical direction of the gravity center position 141 of the maintenance / recovery mechanism 38. This can prevent the frame 38A of the maintenance / recovery mechanism 38 from being deformed when the maintenance / recovery mechanism 38 is fixed.

  Further, the second example shown in FIG. 9 is a relatively heavy maintenance unit 43 maintenance unit 143 (excluding a suction pump, a drive motor, etc.) composed of the cap member 41 and the wiper member 42 of the maintenance / recovery mechanism 38. One fixing portion is provided in the region 144 corresponding to the portion. Thereby, the deformation of the maintenance / recovery mechanism 38 due to the load of the head maintenance operation by the maintenance / recovery mechanism 38 can be prevented.

Next, two fixing parts on the side of the conveyor belt 35 of the maintenance / recovery mechanism 38 will be described with reference to FIGS. 10 and 11.
The fixing portions (connecting portions 131 and 132) to the second fixing member 112 shared by the maintenance and recovery mechanism 38 with the conveyance belt 35 are arranged such that the surfaces (belt surfaces) of the maintenance and recovery mechanism 38 and the conveyance belt 35 are parallel to each other. Is located. At this time, the positional relationship between the two fixed portions may be provided at any location as long as the parallelism between the two units is determined. The positional relationship between the head surface and the conveyor belt surface is determined by making the fixing portions of the conveyor belt 35 and the maintenance / recovery mechanism 38 parallel, and the maintenance / recovery mechanism and the head surface (the nozzle surface 31a of the recording head 24) are parallel. it can.

Next, a second embodiment of the present invention will be described with reference to FIG. In addition, FIG. 12 is a perspective view of a main part of the maintenance and recovery mechanism according to the embodiment.
Here, a rotation restricting portion 151 for restricting the rotation of the maintenance and recovery mechanism 38 is provided at a location different from the fixing portion 121 in the first fixing member 111 shared by the maintenance and recovery mechanism 38 with the guide rod 21. The rotation restricting portion 151 may have any shape such as a rib shape or a shaft shape, and prevents the maintenance and recovery mechanism 38 from being twisted and rotated. The rotation restricting portion 151 restricts the rotation of the maintenance and recovery mechanism 38 by engaging with the first fixing member 111.

  As a result, it is possible to prevent misalignment during the head maintenance operation of the maintenance / recovery mechanism 38 or when the maintenance / recovery mechanism 38 is fixed.

  In this case, as shown in FIG. 12, the rotation restricting portion 151 can be more reliably restricted from rotation by being provided in the region 152 other than the region corresponding to the head maintenance portion 143 of the maintenance and recovery mechanism 38.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 13 is an explanatory perspective view of a main part of the printing unit in the embodiment.
Here, the first fixing member 111 is provided with a fixing portion 111a for fixing one end portion of a linear scale 160 constituting a linear encoder for detecting the position of the carriage 23. The fixed portion 111a may be shaped to lock one end portion of the linear scale 160. Further, the fixing portion 111 a has a shape that can fix the linear scale 160 to be perpendicular to the transport belt 35 when the linear scale 160 is fixed.

  Thus, by providing the linear scale 160 for position detection on the first fixing member 111, the positional relationship between the guide rod 21 and the linear scale 160 can be determined, and the position of the carriage can be detected accurately. . The carriage and the linear scale can be accurately determined in parallel by positioning the conveyor belt and the linear scale vertically and fixing them to the fixing member.

  In addition, the fixing portion 111a of the first fixing member 111 has a shape in which the linear scale is perpendicular to the conveyance belt surface by fixing the linear scale 160, so that the carriage 23 and the linear scale 160 are accurately parallel. Can be decided.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. 14 is an explanatory front view of the printing unit according to the embodiment, and FIG. 15 is a perspective explanatory view of the main part of the printing unit.
Here, in addition to the third embodiment, a third fixing member 113 for fixing the other end of the guide rod 21 is provided, and the other end of the linear scale 160 is fixed to the third fixing member 113. A fixing portion 113a is provided. The fixing portion 113a of the third fixing member 113 also positions and fixes the linear scale 160 perpendicularly to the conveyor belt surface.

  As a result, the carriage and the linear scale can be accurately determined by positioning the conveyor belt and the linear scale vertically and fixing them to the third fixing member.

Next, a fifth embodiment of the present invention will be described with reference to FIG. FIG. 16 is an explanatory front view of the printing unit in the embodiment.
Here, the maintenance / recovery mechanism 38 is provided with a connecting portion 121 that engages with the hole 122 of the first fixing member 111 from the outside, and is detachable from the maintenance mechanism mounting opening 171 formed in the left outside plate 101A. Wearing. Thereby, the recyclability of the maintenance and recovery mechanism can be improved.

1 is a schematic configuration diagram illustrating an overall configuration of an image forming apparatus to which the present invention is applied. FIG. 2 is an explanatory diagram on the left side of FIG. It is a perspective explanatory view of a printing part of the same device. It is perspective explanatory drawing seen from the bottom face of the carriage of the same apparatus. FIG. 2 is a front explanatory view of a printing unit showing the first embodiment of the present invention in the image forming apparatus. It is a principal part perspective explanatory drawing similarly. It is a principal part perspective explanatory drawing similarly used for description of the fixing | fixed part by the side of a maintenance recovery mechanism. It is a principal part perspective explanatory drawing for description of the example of arrangement | positioning of the fixing | fixed part by the side of the 1st fixing member of a maintenance recovery mechanism similarly. It is a principal part perspective explanatory drawing used for description of the other example of the example of arrangement | positioning of the fixing | fixed part by the side of the 1st fixing member of a maintenance recovery mechanism similarly. It is a principal part perspective explanatory drawing similarly used for description of the fixing part by the side of the 2nd fixing member of a maintenance recovery mechanism. It is front explanatory drawing similarly. It is principal part perspective explanatory drawing of the maintenance recovery mechanism which concerns on 2nd Embodiment of this invention. It is principal part perspective explanatory drawing of the printing part which concerns on 3rd Embodiment of this invention. It is front explanatory drawing of the printing part which concerns on 4th Embodiment of this invention. It is a principal part perspective explanatory drawing similarly. It is front explanatory drawing of the printing part which concerns on 5th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Apparatus main body 2 ... Image reading part 3 ... Recording part 4 ... Paper feed cassette part P ... Paper (recording medium)
DESCRIPTION OF SYMBOLS 10 ... Printing part 23 ... Carriage 24 ... Recording head 31 ... Nozzle 35 ... Conveyance belt 38 ... Maintenance recovery mechanism 111 ... 1st fixing member 112 ... 2nd fixing member 113 ... 3rd fixing member 121, 131, 132 ... Connecting part (fixed part)

Claims (13)

Conveying means including a conveying belt for conveying a recording medium;
A carriage equipped with a recording head for discharging droplets;
A guide rod serving as a carriage movement reference;
Maintenance and recovery mechanism of the recording head;
One first fixing member that fixes one end of the guide rod and the maintenance / recovery mechanism, and determines a position of the maintenance / recovery mechanism with respect to the guide rod;
An image forming apparatus comprising: the maintenance / recovery mechanism and the conveyance belt; and a second fixing member that determines a position of the maintenance / recovery mechanism with respect to the conveyance belt.   2. The image forming apparatus according to claim 1, wherein the maintenance / recovery mechanism is connected to the first fixing member at one point, and is connected to the second fixing member at two points. .   3. The image forming apparatus according to claim 2, wherein a connecting portion between the maintenance / recovery mechanism and the first fixing member is positioned in a direction perpendicular to the center of gravity of the maintenance / recovery mechanism. .   The image forming apparatus according to claim 2, wherein a connecting portion between the maintenance / recovery mechanism and the first fixing member is positioned in a direction perpendicular to a head maintenance portion of the maintenance / recovery mechanism. Forming equipment.   5. The image forming apparatus according to claim 2, wherein the conveyance belt and the maintenance / recovery mechanism are positioned in parallel at two connecting portions between the maintenance / recovery mechanism and the second fixing member. An image forming apparatus.   6. The image forming apparatus according to claim 1, wherein at least one of the first fixing member and the maintenance / recovery mechanism is provided with a restricting unit that restricts rotation of the maintenance / recovery mechanism. An image forming apparatus.   The image forming apparatus according to claim 6, wherein the restricting unit is provided outside a maintenance section of the maintenance / recovery mechanism.   8. The image forming apparatus according to claim 1, wherein the first fixing member is detachable.   9. The image forming apparatus according to claim 1, wherein the first fixing member has a fixing portion for fixing the linear scale for detecting the carriage position. .   10. The image forming apparatus according to claim 9, wherein the linear scale is fixed to the first fixing member so as to be positioned perpendicular to the surface of the conveyance belt.   11. The image forming apparatus according to claim 9, wherein a third fixing member for fixing the guide rod and the linear scale is provided on the other end portion side of the guide rod. apparatus.   12. The image forming apparatus according to claim 11, wherein the linear scale is fixed to the third fixing member so as to be perpendicular to the conveyance belt surface.   13. The image forming apparatus according to claim 1, wherein the maintenance / recovery mechanism is detachably mounted.

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