JP2013233791A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of replacing heads and easily positioning the heads with high accuracy.SOLUTION: An image forming apparatus includes: a head holder 51 that holds a recording head 6; and a carriage 5 that holds the head holder 51. The carriage 5 is movable along a guide member 3 arranged in a scanning direction and the carriage 5 includes a reference axis member 71 arranged in the same direction with the guide member 3. The head holder 51 is held so that it is hooked on the reference axis member 71 by a hook 53 to be attachable and detachable. A holder pressurization means 80 pressurizes head holders 51A, 51B, and presses the head holder 51 on the reference axis member 71. The holder pressurization means 80 has an adjusting means 85 for adjusting a pressurization force when pressurizing each of the holders 51.

Description

  The present invention relates to an image forming apparatus.

  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 apparatus using a liquid discharge head (droplet discharge head) for discharging droplets as a recording head An ink jet recording apparatus is known.

  By the way, when an image is formed in an image forming apparatus using a liquid ejection method, the landing accuracy of droplets ejected from nozzles greatly affects the image quality, and if the landing accuracy of droplets is poor, the image quality is degraded. Therefore, it is necessary to position the recording head with high accuracy.

  On the other hand, it is necessary to make it possible to easily replace the head under the usage environment of the user, such as when a discharge failure occurs in the recording head. In this case as well, reproducibility with high position accuracy must be provided.

  2. Description of the Related Art Conventionally, a head holder for mounting a plurality of liquid discharge heads and a carriage for detachably holding the head holder are provided as positioning accuracy at the time of head replacement, and the head holder is a carriage provided on the carriage. A positioning unit that is in contact with a positioning reference in the scanning direction and the sheet conveyance direction is known, and the positioning unit serves as a positioning reference for the head holder of the liquid ejection head (Patent Document 1).

JP 2011-037235 A

  However, in the configuration disclosed in Patent Document 1 described above, the positioning of the head holder with respect to the carriage is performed by the positioning surface and the positioning pins, which makes the configuration complicated.

  The present invention has been made in view of the above problems, and an object of the present invention is to enable easy positioning of a head with high accuracy.

In order to solve the above problems, an image forming apparatus according to the present invention provides:
A plurality of recording heads having a plurality of nozzles for discharging droplets;
A plurality of head holders for holding the recording head;
A carriage for holding the head holder,
The carriage is movable along a guide member disposed in a main scanning direction;
The carriage has a reference member disposed in the same direction as the guide member,
Each of the plurality of head holders is held by the reference member,
A holder pressurizing unit that pressurizes the plurality of head holders and presses the head holder against the reference member;
The holder pressurizing means has an adjusting means for adjusting the pressure applied when pressurizing each head holder.

  According to the image forming apparatus of the present invention, the head can be easily positioned with high accuracy.

1 is an external perspective view illustrating an entire configuration of an example of an image forming apparatus according to the present invention. It is a perspective explanatory view of a carriage scanning mechanism part of the same device. It is a typical perspective explanatory view of a carriage part explaining a state before mounting a head holder in a 1st embodiment to a carriage to the present invention. It is a perspective explanatory view of the carriage part explaining the state where the head holder was similarly attached to the carriage. It is side surface explanatory drawing of the carriage part with which it uses for description of the holder pressurization means which pressurizes the head holder in the embodiment. It is a perspective explanatory view similarly. It is a principal part front cross-section explanatory drawing similarly. FIG. 5 is a schematic side view for explaining the head position adjusting function. It is a perspective explanatory view of a carriage part for explanation of a second embodiment of the present invention. It is a principal part perspective explanatory drawing similarly. It is a side explanatory view similarly. It is side explanatory drawing which abbreviate | omitted the cover member similarly. It is front explanatory drawing similarly. It is front explanatory drawing which abbreviate | omitted the cover member similarly.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. An example of an image forming apparatus according to the present invention will be described with reference to FIGS. 1 is an explanatory perspective view showing the overall configuration of the recording apparatus, and FIG. 2 is an explanatory perspective view of the carriage scanning mechanism.

  This image forming apparatus is a serial type ink jet recording apparatus, and includes an apparatus main body 1 and a support base 2 that supports the recording apparatus main body 1.

  Inside the apparatus main body 1, a guide rod 3 and a guide stay 4, which are guide members, are spanned on both side plates (not shown), and a carriage 5 can slide in the direction indicated by the arrow A on the guide rod 3 and the guide stay 4. Is held in.

  On the carriage 5, a recording head 6 including a liquid ejection head that ejects ink droplets of each color of black (K), yellow (Y), magenta (M), and cyan (C) is mounted. Although not shown, each recording head 6 is integrally provided with a head tank that supplies ink to each recording head.

  The main scanning mechanism 10 that moves and scans the carriage 5 is disposed on one side in the main scanning direction, a driving pulley 12 that is rotationally driven by the driving motor 11, and on the other side in the main scanning direction. The driven pulley 13 is provided, and a timing belt 14 that is a pulling member wound between the drive pulley 12 and the driven pulley 13 is provided. The driven pulley 13 is tensioned outward (in a direction away from the drive pulley 12) by a tension spring (not shown).

  Among the main scanning areas in the carriage 5, in the recording area, the paper 20 is intermittently moved in the direction orthogonal to the main scanning direction of the carriage 5 by the suction conveyance unit 7 (sub-scanning direction, paper conveyance direction: arrow B direction). Be transported.

  In addition, a maintenance / recovery mechanism 8 that performs maintenance / recovery of the recording head 6 is disposed in one end side region of the main scanning region. Further, a main cartridge 9 containing each color ink to be supplied to the sub tank of the recording head 6 is located outside the carriage movement area in the main scanning direction or in the other end side area of the main scanning area. And is detachably mounted.

  In addition, roll paper (hereinafter referred to as “paper”) 20 is set in the paper supply unit 21, but roll papers having different sizes in the width direction can be set. The sheet 20 conveyed from the sheet feeding unit 21 is conveyed from the rear of the apparatus main body 1 to the front by the conveying unit to the recording area. Then, the carriage 5 is moved in the main scanning direction, and the recording head 6 is driven according to the image information to eject droplets while intermittently feeding the paper 20 by the suction conveyance unit 7. A required image is formed. Further, the paper 20 after the image formation is cut to a predetermined length and discharged to a paper discharge tray (not shown) arranged on the front side of the apparatus main body 1.

  Next, a first embodiment of the present invention will be described with reference to FIGS. 3 is a schematic perspective explanatory view of the carriage portion for explaining the state before the head holder is mounted on the carriage in the embodiment. FIG. 4 is a perspective view of the carriage portion for explaining the state where the head holder is mounted on the carriage. FIG.

  The carriage 5 holds a black head holder 51A and a color head holder 51B.

  The head holder 51A is equipped with two recording heads 6A and 6B that discharge black droplets arranged in a staggered manner in the sub-scanning direction. The head holder 51B is mounted with three recording heads 6C, 6D, and 6E that discharge yellow, magenta, and cyan droplets at the same position in the sub-scanning direction as the recording head 6A. As described above, when the recording heads are not distinguished, they are referred to as “recording head 6”. The number of recording heads 6 held by the head holders 51A and 51B may be one.

  Here, the carriage 5 is provided with a reference shaft member 71 as a reference member in the same direction as the guide rod 3. “Same direction” means that the axial direction of the guide rod 3 and the axial direction of the reference shaft member 71 are parallel.

  The head holders 51A and 51B (hereinafter referred to as “head holder 51” when not distinguished from each other) are provided with hook-shaped hook portions 53 that are detachably fitted to the reference shaft member 71, and the head holders 51A and 51B. Is held by the carriage 5 by hooking the hook portion 53 on the reference shaft member 71. Note that the reference shaft member 71 may have a cylindrical shape or a polygonal shape.

  Thus, by arranging the reference shaft member 71 in the same direction as the guide member 3 of the carriage 5, the positional accuracy of the tilt in the sub-scanning direction, the height direction, the tilt direction, and the main scanning direction is improved.

  In this embodiment, when head replacement is performed, for example, when the recording heads 6A and 6B are replaced, the head holder 51 is detached from the reference shaft member 71, and the replaced head holder 51 is hooked on the reference shaft member 71 and held. .

  Thereby, the head position accuracy of the replaced head holder 51 can be reproduced, and high position accuracy can be obtained for the head 6 of the other head holder 51.

  As described above, the recording head includes a recording head having a plurality of nozzles for discharging droplets, one or a plurality of head holders that hold one or more recording heads, and a carriage that holds the head holder, and the carriage performs main scanning. The carriage has a reference member arranged in the same direction as the guide member, and the head holder is detachably hooked and held by the reference member. With this configuration, the head can be easily positioned with high accuracy, and the head can be easily replaced.

  Next, a holder pressurizing means (pressurizing mechanism) for pressurizing the head holder in the present embodiment will be described with reference to FIGS. FIG. 5 is an explanatory side view of the carriage portion used to explain the holder pressing means, FIG. 6 is an explanatory perspective view, and FIG.

  As shown in FIG. 5, the head holders 51 </ b> A and 51 </ b> B have at least one abutting portion 58 that comes into contact with the carriage 5. The head holders 51A and 51B have a configuration having a plurality of hooking portions, such as forming the hooking portions 53 at both ends in the main scanning direction as described in the example having one hooking portion 53 in the main scanning direction. It can also be.

  A holder pressurizing mechanism 80 that is a holder pressurizing unit that pressurizes the head holder 51 toward the carriage 5 with the reference shaft member 71 as a rotation center is provided.

  The holder pressurizing mechanism 80 has a cover member 82 that covers at least a part of the head holder 51 and has a rear end portion 82 b rotatably supported by a shaft 81 on the carriage 5. The cover member 82 is a substantially flat member having a step as shown in FIG. 6, for example.

  Here, the two head holders 51A and 51B are used as the common cover member 82, but a configuration in which a cover member is provided for each of the head holders 51A and 51B may be employed.

  Between the cover member 82 and the carriage 5, an elastic member (pressure spring) 83 such as a tension coil spring, which is means for pressing the cover member 82 toward the head holder side, is provided. The cover member 82 is pressurized in the direction toward the head holder 51.

  The cover member 82 holds pressure members 84A and 84B that are pressed against the head holders 51A and 51B, respectively. These pressurizing members 84 are held so as to be movable in the vertical direction with respect to the cover member 82 by a retaining portion 84a.

  The cover member 82 is provided with an adjustment screw 85 as an adjustment means (change member) so as to be able to advance and retreat with respect to the pressure member 84. By rotating the adjustment screw 85, the pressure member 84 and the cover are covered. The distance between the member 82 can be adjusted, and the force (pressing force) by which the pressure member 84 pushes the head holder 51 is changed by changing the distance between the pressure member 84 and the cover member 82. .

  Since the pressure member 84 is pressed against the head holder 51 by the cover member 82, the head holder 51 is rotated clockwise (in the direction of the white arrow) in FIG. 5 with the reference shaft member 71 as the rotation center. Since the pressure is applied and pressed against the reference shaft member 71 and the carriage 5, the posture of the head holder 51 is defined. That is, the posture of the head holder 51 can be determined simply by hooking the head holder 51 on the reference shaft member 71 and closing the cover member 82 (covering the upper portion of the head holder 51).

  As a result, even when head replacement is performed by the user, the head position can be easily determined with high accuracy, and head replacement is facilitated.

  Then, by rotating the adjustment screw 85, as described above, the distance between the pressure member 84 and the cover member 82 is changed, and the pressure (pressing force) by which the pressure member 84 presses the head holder 51. Changes.

  For example, the adjustment screw 85 is screwed into the pressure member 84 side from the state shown in FIG. 8A to increase the distance between the pressure member 84 and the cover member 82. That is, when the adjustment screw 85 is screwed in, the pressure member 84 moves downward in the figure with respect to the cover member 82, thereby increasing the distance between the pressure member 84 and the cover member 82.

  As a result, when the pressure applied to the head holder 51 by the pressure member 84 increases, the head holder 51 rotates downward (arrow C direction) around the reference shaft member 71 as shown in FIG. 8B. Therefore, the position of the head 6 moves upstream in the sub-scanning direction (arrow D direction), and the nozzle position in the sub-scanning direction changes.

  As a result, the nozzle positions in the sub-scanning direction between the black recording heads 6A and 6B held in the head holder 51A and the color recording heads 6C to 6E held in the head holder 51B are finely defined. Can be adjusted.

  In the present embodiment, the pressure member 84A for the head holder 51A and the pressure member 84B for the head holder 51B have different widths in the main scanning direction, so the pressure members 84A and 84B have the same configuration. If there is, the applied force may be different and the amount of tilting of the head holders 51A and 51B (the amount of rotation about the reference shaft member 71) may be different.

  Therefore, in this case, the amount of collapse of the head holders 51A and 51B is the same by varying the plate thickness of the pressure members 84A and 84B and varying the spring properties (elastic force) of the pressure members 84A and 84B. It is preferable to adjust so that. Specifically, here, the thickness of the pressure member 84B is made larger than the thickness of the pressure member 84A.

  That is, since the pressure member 84B has a larger width in the main scanning direction than the pressure member 84A, the deflection is greater than that of the pressure member 84A. Thereby, the pressure member 84B absorbs the applied pressure from the adjustment screw 85 more than the pressure member 84A. Therefore, in order to adjust the tilt amounts of the head holders 51A and 51B to be the same, the plate thickness of the pressure member 84B is made larger than that of the pressure member 84A, and the pressure applied from the adjustment screw 85 is the same. Adjust as follows.

  Similarly, the pressure member 84A for the head holder 51A and the pressure member 84B for the head holder 51B can be held at different holding positions in the sub-scanning direction by the cover member 82. However, if the pressurizing members 84A and 84B have the same configuration, the applied pressure may be different and the tilting amounts of the head holders 51A and 51B may be different.

  Also in this case, similarly, the amount of tilting of the head holders 51A and 51B is made the same by changing the plate thickness of the pressure members 84A and 84B and changing the spring properties of the pressure members 84A and 84B. It is preferable to adjust to.

  Next, a second embodiment of the present invention will be described with reference to FIGS. 9 is a perspective explanatory view of the carriage portion in the same embodiment, FIG. 10 is also a perspective view of the main part, FIG. 11 is also a side explanatory view, FIG. 12 is a side explanatory view in which the cover member is omitted, and FIG. Similarly, FIG. 14 is a front explanatory view in which the cover member is omitted.

  In the present embodiment, as in the previous embodiment, the carriage 5 is provided with a reference shaft member 71 as a reference member in the same direction as the guide rod 3. The reference shaft member 71 holds the intermediate member 101 (the member shown by hatching in FIG. 11), and the head holders 51A and 51B are held by the reference shaft member 71 in the intermediate member 101.

  Although not shown, the carriage 5 is provided with a head lifting mechanism including a cam that lifts and lowers the head 6. The intermediate member 101 is provided with a cam contact surface (not shown) with which the cam of the head lifting mechanism contacts, and the height position of the head 6 changes as the intermediate member 101 is moved up and down by the rotation of the cam. It is configured to do.

  Further, the intermediate member 101 is formed with an abutting surface 101a (see FIG. 11) on which the abutting portion 58 of the head holder 51 comes into contact and the head holder 51 is positioned.

  Since other configurations are the same as those of the first embodiment, the same reference numerals are given and description thereof is omitted.

  In the above embodiment, although the example in which the adjusting means is an adjusting screw has been described, the present invention is not limited to this, and any means that can change the distance between the pressure member such as a cam mechanism and the cover member. There is no particular limitation.

  In each of the above embodiments, the adjusting means is provided in both the pressure member 84A for the head holder 51A and the pressure member 84B for the head holder 51B. The adjusting means may be provided only on the pressure member corresponding to the other head holder 51 except the head holder 51.

  For example, in the above embodiment, the head holder 6C to 6E mounted on the color head holder 51B can be adjusted with reference to the heads 6A and 6B mounted on the black head holder 51A. It is also possible to provide the adjusting means only on the pressure member 84B for the head holder 51B without providing the adjusting means on the pressure member 84A for 51A.

  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.

DESCRIPTION OF SYMBOLS 1 Apparatus main body 5 Carriage 6, 6A-6D Recording head 51, 51A, 51B Head holder 53 Hook part 71 Reference | standard shaft member (reference | standard member)
80 Holder pressurizing means (holder pressurizing mechanism)
82 Cover member 83 Elastic member 84, 84A, 84B Pressure member 85 Adjustment screw (Adjustment means)

Claims (6)

A plurality of recording heads having a plurality of nozzles for discharging droplets;
A plurality of head holders for holding the recording head;
A carriage for holding the head holder,
The carriage is movable along a guide member disposed in a main scanning direction;
The carriage has a reference member disposed in the same direction as the guide member,
Each of the plurality of head holders is held by the reference member,
A holder pressurizing unit that pressurizes the plurality of head holders and presses the head holder against the reference member;
The image forming apparatus according to claim 1, wherein the holder pressurizing unit includes an adjusting unit that adjusts a pressing force when the head holder is pressed. The holder pressing means is
A cover member covering at least a part of the head holder;
Means for pressurizing the cover member toward the head holder;
A pressure member held by the cover member and pressed against the plurality of head holders,
The image forming apparatus according to claim 1, wherein the adjusting unit is a unit that adjusts a distance between at least one of the pressure member and the cover member.   The image forming apparatus according to claim 2, wherein the adjusting unit is provided in the pressure member corresponding to another head holder excluding a reference head holder.   4. The image forming apparatus according to claim 2, wherein the pressing members corresponding to the plurality of head holders have different elastic forces.   The image forming apparatus according to claim 1, wherein the cover member is one member that covers each of the plurality of head holders.   6. The image forming apparatus according to claim 2, wherein the pressure member is held by the cover member via a retaining portion.

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