Inkjet image forming apparatus

Abstract

To highly accurately adjust the position of a head module in a first direction relative to a mounting base.SOLUTION: The head module is provided in a mounting base so as to be positionally adjustable in a first direction, and an adjustment member is provided in the mounting base so as to be movable in a second direction intersecting the first direction. The adjustment member includes an abutting portion that makes into contact with an abutted portion on the head module side, and the first biasing member biases the abutted portion to the abutting portion side. At least one of the abutted portions and the abutting portion is an inclined surface inclined with respect to the second direction.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an inkjet image forming apparatus.

Background Art

[0002] In an inkjet image forming apparatus, a head module that discharges ink onto a recording medium is positionally adjustable in a first direction with respect to a mounting base. For example, as shown in Patent Document 1, an operation member (referred to as an adjustment screw in Patent Document 1) is provided on the mounting base so as to be movable in a second direction orthogonal to the first direction via a reference block. The operation member has a screw portion in the middle thereof.

[0003] An adjustment block for positionally adjusting the head module in the first direction is screwed onto the screw portion of the operation member. The adjustment block has a screw hole for screwing the screw portion of the operation member. The adjustment block is configured to be non-rotatable with respect to the reference block (mounting base). The adjustment block has a contact portion (referred to as an inclined surface in Patent Document 1) that contacts a contact portion on the head module side (referred to as an inclined surface of a moving body in Patent Document 1).

[0004] A ball plunger that biases the contact portion to the contact portion side is provided at an appropriate position on the mounting base. The contact portion on the head module side and the contact portion of the adjustment block are each an inclined surface inclined with respect to the second direction so that the movement of the operation member in the second direction is converted into the movement of the head module in the first direction. The inclined surface of the contact portion of the adjustment block is inclined in the direction opposite to the inclined surface of the contact portion on the head module side.

[0005] With the above configuration, when the operating member rotates by a rotational operation, the adjustment block moves in the second direction (axial direction of the operating member) due to the screwing action between the screw portion of the operating member and the screw hole of the adjustment block. Then, with the contact between the contact portion on the head module side and the contact portion of the adjustment block maintained by the biasing force of the ball plunger, the head module moves in the first direction. Thereby, the position of the head module can be adjusted in the first direction with respect to the mounting base.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] By the way, since the adjustment block having the operating member and the contact portion is a separate part, play is likely to occur between the operating member and the contact portion of the adjustment block when the adjustment block is attached to the operating member. When the adjustment block moves in the second direction due to the screwing action between the screw portion of the operating member and the screw hole of the adjustment block, a minute eccentric movement of the contact portion of the adjustment block with respect to the axis of the operating member occurs. Therefore, even if the operating member is moved in the second direction by a rotational operation, there is a problem that it is difficult to accurately position-adjust the head module in the first direction with respect to the mounting base.

[0008] Therefore, an object of the present invention is to provide an inkjet image forming apparatus capable of accurately position-adjusting a head module in a first direction with respect to a mounting base.

Means for Solving the Problems

[0009] One aspect of the inkjet image forming apparatus of the present invention is a head module provided on a mounting base so as to be position-adjustable in a first direction, and It is provided movably in a second direction intersecting the first direction on the mounting base, has a contact portion that contacts the contact portion on the head module side, and is an adjustment member for adjusting the position of the head module in the first direction. It includes a first biasing member that biases the contact portion toward the contact portion side. At least one of the contact portion and the contact portion has an inclined surface inclined with respect to the second direction so that the movement of the adjustment member in the second direction is converted into the movement of the head module in the first direction.

Effect of the Invention

[0010] According to the present invention, the head module can be accurately position-adjusted in the first direction with respect to the mounting base.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Best Mode for Carrying Out the Invention

[0012] Hereinafter, this embodiment will be described with reference to the drawings. In this embodiment, the conveyance direction refers to the conveyance direction in which the recording medium is conveyed. The downstream side refers to the downstream side in the conveyance direction, and the upstream side refers to the upstream side in the conveyance direction. Further, in this embodiment, the X-axis direction refers to the main scanning direction, which is a direction orthogonal to the conveyance direction. The Y-axis direction refers to the sub-scanning direction, which is the conveyance direction. The Z-axis direction refers to a direction orthogonal to the X-axis direction and the Y-axis direction. The Z-axis direction corresponds to the first direction, and the Y-axis direction corresponds to the second direction. In this embodiment, the second direction is orthogonal to the first direction, but it may not be orthogonal to the first direction as long as it intersects the first direction.

[0013] With reference to FIGS. 1 and 2, the overall configuration of the inkjet image forming apparatus 10 according to this embodiment will be described. FIG. 1 is a schematic front view of the inkjet image forming apparatus 10 according to this embodiment. FIG. 2 is a schematic bottom view of the head unit 42 according to this embodiment, showing a state in which a plurality of head modules 46 are attached to the carriage 44.

[0014] As shown in FIG. 1, the inkjet image forming apparatus 10 according to this embodiment is a single-pass type recording apparatus that forms a color image on the recording medium P by discharging four colors of ink toward the recording medium P at an appropriate timing while moving the recording medium P in the conveyance direction. As the recording medium P, in addition to paper such as plain paper and coated paper, various media capable of fixing the ink landing on the surface, such as cloth and resin film, can be used. In the inkjet image forming apparatus 10, ink that undergoes a phase change between a gel state and a sol state (liquid state) depending on the temperature is used. For example, energy ray irradiation type ink such as UV ink that forms a gel state at normal temperature, changes to a sol state when heated, and solidifies when irradiated with energy rays during image formation can be used.

[0015] The inkjet image forming apparatus 10 includes an apparatus main body 12. The apparatus main body 12 has a center frame 14, a first side frame 16 disposed on one side of the center frame 14, and a second side frame 18 disposed on the other side of the center frame 14.

[0016] A paper feeding unit 20 for feeding the recording medium P is provided on the first side frame 16. The paper feeding unit 20 has a plate-shaped paper feeding tray 22 for placing the recording medium P, and the paper feeding tray 22 is provided on the first side frame 16 so as to be movable in the vertical direction. The paper feeding tray 22 is configured to move up and down according to the amount of the recording medium P to be placed, and the uppermost recording medium P is held at a predetermined height position.

[0017] The paper feeding unit 20 has a conveying unit 24 for conveying the recording medium P sent out from the paper feeding tray 22 in the conveying direction, and the conveying unit 24 is provided across the first side frame 16 and the center frame 14. The conveying unit 24 has a plurality of rotatable support rollers 26 and an endless belt 28 provided so as to be wound around the plurality of support rollers 26. By circulating the belt 28 by the rotation of the plurality of support rollers 26, the recording medium P sent out from the paper feeding tray 22 is conveyed in the conveying direction.

[0018] An image forming unit 30 for discharging ink onto the recording medium P to form an image is provided on the center frame 14. The image forming unit 30 has an image forming drum 32 for carrying the recording medium P, and the image forming drum 32 is rotatably provided on the center frame 14. With the recording medium P carried on the outer peripheral surface (conveying surface) of the image forming drum 32, the image forming drum 32 is rotated by driving a motor (not shown) for the image forming drum, thereby conveying the recording medium P in the conveying direction. Note that the image forming drum 32 has a claw portion (not shown) for pressing the end portion of the recording medium P and a suction portion (not shown) for sucking the recording medium P.

[0019] The image forming unit 30 has a delivery unit 34 for delivering the recording medium P from the conveyance unit 24 to the image forming drum 32. The delivery unit 34 is provided between the conveyance unit 24 and the image forming drum 32 in the center frame 14. The delivery unit 34 has a swing arm 36 that supports one end of the recording medium P conveyed by the conveyance unit 24, and a delivery drum 38 that delivers the recording medium P carried by the swing arm 36 to the image forming drum 32. By supporting one end of the recording medium P on the conveyance unit 24 with the swing arm 36 and delivering it to the delivery drum 38, the recording medium P is delivered from the delivery drum 38 to the image forming drum 32.

[0020] The image forming unit 30 has a medium heating unit 40 for heating the recording medium P carried on the image forming drum 32. The medium heating unit 40 is provided on the downstream side of the delivery drum 38 in the center frame 14. The medium heating unit 40 is arranged to face the outer peripheral surface of the image forming drum 32. The medium heating unit 40 has, for example, an infrared heater or the like, and heats the image forming drum 32 and the recording medium P so that the recording medium P conveyed by the image forming drum 32 reaches a temperature within a predetermined range.

[0021] As shown in FIGS. 1 and 2, the image forming unit 30 has a plurality of head units 42 that eject ink onto the recording medium P carried on the image forming drum 32 to form an image. The plurality of head units 42 are arranged on the downstream side of the medium heating unit 40. The plurality of head units 42 are units corresponding to four colors of ink: yellow (Y), magenta (M), cyan (C), and black (K). The plurality of head units 42 corresponding to the four colors of ink Y, M, C, and K are arranged at intervals along the conveyance direction from the upstream side. Each head unit 42 is held by each carriage 44 provided movably in the main scanning direction on the center frame 14. In other words, each head unit 42 is provided on the center frame 14 so as to be movable in the main scanning direction via each carriage 44. Each carriage 44 is made of, for example, an aluminum alloy.

[0022] Each head unit 42 has a plurality of head modules 46 that eject ink onto the recording medium P. The plurality of head modules 46 are provided on the carriage 44 as a mounting base so as to be positionally adjustable in the Y-axis direction. The plurality of head modules 46 are arranged, for example, in a staggered pattern along the main scanning direction (X-axis direction). In other words, each head unit 42 constitutes a line head including a plurality of head modules 46.

[0023] As shown in FIG. 1, the image forming unit 30 has a fixing unit 48 for fixing the ink onto the recording medium P. The fixing unit 48 is provided on the downstream side of the plurality of head units 42 in the center frame 14. The fixing unit 48 is arranged to face the outer peripheral surface of the image forming drum 32. The fixing unit 48 has a light emitting unit that irradiates energy rays such as ultraviolet rays. By applying predetermined energy to the ink ejected onto the recording medium P by the light emitting unit of the fixing unit 48, the ink is cured and fixed onto the recording medium P.

[0024] The image forming unit 30 has a delivery unit 50 that conveys the recording medium P irradiated with energy rays in the conveyance direction from the image forming drum 32. The delivery unit 50 is provided across the center frame 14 to the second side frame 18. The delivery unit 50 has a plurality of rotatable support rollers 52, an endless belt 54 provided so as to be wound around the plurality of support rollers 52, and a delivery drum 56 that transfers the recording medium P from the image forming drum 32 to the belt 54. By circulating the belt 54 by the rotation of the plurality of support rollers 52, the recording medium P sent out from the image forming drum 32 is conveyed in the conveyance direction.

[0025] The second side frame 18 is provided with a paper discharge unit 58 for discharging the printed recording medium P. The paper discharge unit 58 has a plate-shaped paper discharge tray 60 for placing the printed recording medium P. The paper discharge unit 58 stores the recording medium P until the user takes out the recording medium P from the paper discharge tray 60.

[0026] Next, with reference to FIGS. 3 to 9, the specific configuration of the head module 46 according to this embodiment will be described. FIG. 3 is a schematic perspective view of the head module 46 attached to the carriage 44. FIG. 4 is a schematic front view of the head module 46 attached to the carriage 44. FIG. 5 is a schematic side view of the head module 46 attached to the carriage 44. FIG. 6 is a schematic bottom view of the head module 46 attached to the carriage 44. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 4. FIG. 8 is an enlarged view of part VIII in FIG. 4. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 8. Note that in FIGS. 3 to 9, a part of the carriage 44 is conceptually shown.

[0027] As shown in FIGS. 3 to 6, the head module 46 according to this embodiment is provided on the carriage 44 as a mounting base so as to be position-adjustable in the Y-axis direction, and closes the through hole 44h formed in the carriage 44. Further, the head module 46 includes a plate-shaped module base 62 provided on the carriage 44 so as to be position-adjustable in the Y-axis direction, and a plurality of inkjet heads 64 provided on the module base 62 for discharging ink. The upper portions of the plurality of inkjet heads 64 are supported by a support member 66 fixed to the carriage 44. Note that the support member 66 may be regarded as a member constituting a part of the carriage 44.

[0028] Each inkjet head 64 has a common ink chamber (not shown) for storing ink therein, and the common ink chamber is connected to an ink supply device (not shown) for supplying ink. Further, each inkjet head 64 has a head chip 68 on its bottom surface side, and the head chip 68 has a plurality of nozzles 68n for discharging ink.

[0029] The head chip 68 is formed with a plurality of pressure chambers (not shown) for each nozzle 68n, and each pressure chamber communicates with a common ink chamber and the corresponding nozzle 68n. Each pressure chamber is configured to be pressurized by driving a driving element (not shown) such as a piezo element or a heating element. Each nozzle 68n is configured to eject (inject) ink when the corresponding pressure chamber is pressurized.

[0030] In order to enable the head module 46 to be position-adjustable in the Y-axis direction with respect to the carriage 44 which is a mounting base, the head module 46 and the like have the following configuration.

[0031] As shown in FIGS. 6 and 7, a first positioning member 70 is provided on the edge side in the Y-axis direction of the carriage 44, and the first positioning member 70 has a first positioning hole 70h corresponding to a round hole. In other words, a first positioning hole 70h is provided on the edge side in the Y-axis direction of the carriage 44 via the first positioning member 70. Further, a second positioning member 72 is provided movably in the Y-axis direction at a position separated from the first positioning member 70 in the X-axis direction on the edge side in the Y-axis direction of the carriage 44. The second positioning member 72 has a second positioning hole 72h which is a long hole extending in the X-axis direction.

[0032] The head module 46 has a first positioning pin 74 provided on the bottom surface of the module base 62, and the first positioning pin 74 engages with the first positioning hole 70h of the first positioning member 70. When the first positioning pin 74 engages with the first positioning hole 70h of the first positioning member 70, the movement of the head module 46 in the Y-axis direction is converted into a rotational movement (movement in the rotational direction) centered on the first positioning pin 74.

[0033] The head module 46 has a second positioning pin 76 provided at a position spaced apart from the first positioning pin 74 on the bottom surface of the module base 62 in the X-axis direction. The second positioning pin 76 engages with the second positioning hole 72h of the second positioning member 72. When the second positioning pin 76 engages with the second positioning hole 72h of the second positioning member 72, the second positioning pin 76 moves in the X-axis direction along the second positioning hole 72h of the second positioning member 72 during the rotational movement of the head module 46.

[0034] As shown in FIGS. 7 to 9, a block body 78 is provided in the vicinity of the second positioning member 72 at the edge of the carriage 44 in the Y-axis direction. Both sides of the block body 78 in the Y-axis direction are open (released). A screw hole 78b is formed in the upper part of the block body 78, and a fitting hole 78h is formed in the lower part of the block body 78. In other words, a screw hole 78b and a fitting hole 78h are provided at the edge of the carriage 44 in the Y-axis direction via the block body 78, respectively. The block body 78 may be regarded as a member constituting a part of the carriage 44.

[0035] As shown in FIG. 9, a vertical adjustment member 80 for adjusting the position of the head module 46 in the Y-axis direction is provided movably in the Z-axis direction on the block body 78. In other words, an adjustment member 80 is provided movably in the Z-axis direction at the edge of the carriage 44 in the Y-axis direction via the block body 78. Further, the adjustment member 80 has a screw portion 82 at its upper part that engages with the screw hole 78b of the block body 78 (the screw hole 78b of the carriage 44). The adjustment member 80 moves in the Z-axis direction by a rotational operation of a tool (not shown) connected from one side in the Z-axis direction. The adjustment member 80 has a fitting portion 84 at its lower part that is movably fitted in the fitting hole 78h of the block body 78 (the fitting hole 78h of the carriage 44) in the Z-axis direction. Although the adjustment member 80 is configured to be able to connect a tool from one side in the Z-axis direction, it may be configured to be able to connect a tool from the other side in the Z-axis direction.

[0036] The adjusting member 80 has an annular flange portion 86 at a position in its middle portion closer to the fitting portion 84. The outer peripheral surface 86p of the flange portion 86 abuts against the end surface 72e in the Y-axis direction, which is a part of the second positioning member 72. The end surface 72e in the Y-axis direction of the second positioning member 72 is a portion to be abutted on the head module 46 side, and the outer peripheral surface 86p of the flange portion 86 is an abutting portion that abuts against the portion to be abutted on the head module 46 side. The distance in the Z-axis direction between the outer peripheral surface 86p of the flange portion 86 and the fitting portion 84 is shorter than the distance in the Z-axis direction between the outer peripheral surface 86p of the flange portion 86 and the threaded portion 82.

[0037] As shown in FIGS. 3 to 5, a leaf spring 88 as a first biasing member for biasing the head module 46 to one side in the Y-axis direction is provided at the lower portion of the support member 66. By biasing the head module 46 to one side in the Y-axis direction, the leaf spring 88 biases the end surface 72e in the Y-axis direction of the second positioning member 72 toward the outer peripheral surface 86p side of the flange portion 86 of the adjusting member 80. Further, as shown in FIG. 9, a coil spring 90 as a second biasing member for biasing the outer peripheral surface 86p of the flange portion 86 toward the end surface 72e side in the Y-axis direction of the second positioning member 72 is provided between the flange portion 86 of the adjusting member 80 and the upper portion of the block body 78.

[0038] As shown in FIG. 9, the end surface 72e of the second positioning member 72 is an inclined surface inclined with respect to the Y-axis direction so that the movement of the adjusting member 80 in the Z-axis direction is converted into the movement of the head module 46 in the Y-axis direction. The outer peripheral surface 86p of the flange portion 86, which is the abutting portion, is an R surface. Instead of making the outer peripheral surface 86p of the flange portion 86 an R surface, it may be an inclined surface or an edge (sharp surface) inclined in the direction opposite to the end surface 72e of the second positioning member 72. When the outer peripheral surface 86p of the flange portion 86, which is the abutting portion, is an R surface or an edge, the hardness of the end surface 72e in the Y-axis direction of the second positioning member 72, which is the portion to be abutted, is made higher than the hardness of the outer peripheral surface 86p of the flange portion 86.

[0039] The moving amount of the head module 46 in the Y-axis direction is smaller than the moving amount of the adjusting member 80 in the Z-axis direction. The moving amount of the head module 46 in the Y-axis direction is proportional to the moving amount of the adjusting member 80 in the Z-axis direction. Also, as described above, the movement of the head module 46 in the Y-axis direction is converted into a rotational movement centered on the first positioning pin 74.

[0040] With the above configuration, when the adjusting member 80 rotates due to the rotational operation of the tool, the adjusting member 80 moves in the Z-axis direction due to the screwing action between the screw portion 82 of the adjusting member 80 and the screw hole 78b of the block body 78. Then, while maintaining the contact between the outer peripheral surface 86p of the flange portion 86 and the end surface 72e of the second positioning member 72 by the biasing forces of the leaf spring 88 and the coil spring 90, the head module 46 makes a rotational movement centered on the first positioning pin 74 while moving in the Y-axis direction. Thereby, the position of the head module 46 can be adjusted in the Y-axis direction with respect to the carriage 44, and the inclination of the head module 46 with respect to the X-axis direction (the longitudinal direction of the carriage 44) can be adjusted.

[0041] As shown in FIGS. 3 to 5, pressing units 92 for pressing the head module 46 toward the carriage 44 by elastic forces are respectively provided on both sides of the head module 46 in the X-axis direction in the carriage 44. The specific configuration of each pressing unit 92 is as follows.

[0042] As shown in FIGS. 3 to 5 and FIG. 8, a screw member 94 is screwed and provided on one side or the other side of the head module 46 in the X-axis direction in the carriage 44, and the screw member 94 has a head 96 at its upper end. A movable ring 98 that abuts against the end portion of the module base 62 in the X-axis direction is provided movably in the Z-axis direction (the axial direction of the screw member 94) on the screw member 94.

[0043] Between the head 96 of the screw member 94 and the movable ring 98, a coil spring 100 is provided as a pressing member that presses the movable ring 98 toward the module base 62 by an elastic force. When the coil spring 100 presses the movable ring 98 toward the module base 62 by an elastic force, the head module 46 is pressed toward the carriage 44 by an elastic force. By changing the tightening amount of the screw member 94, the pressing force by the pressing unit 92 can be adjusted. The pressing force by the pressing unit 92 is set to a pressing force that does not inhibit the position adjustment of the head module 46 in the Y-axis direction. Note that FIGS. 3 to 5 and FIG. 8 show the state before the movable ring 98 is pressed toward the module base 62.

[0044] According to the configuration of the inkjet image forming apparatus 10 according to the present embodiment, as described above, the adjustment member 80 is provided on the edge portion in the Y-axis direction of the carriage 44 so as to be movable in the Z-axis direction via the block body 78. The adjustment member 80 has an outer peripheral surface 86p of the flange portion 86 as an abutting portion that abuts against an abutting portion (the end surface 72e in the Y-axis direction of the second positioning member 72) on the head module 46 side. Therefore, the adjustment member 80 has a function as an operating member according to the prior art and a function as an adjustment block according to the prior art. As a result, play does not occur between the main body of the adjustment member 80 and the outer peripheral surface 86p of the flange portion 86, and the outer peripheral surface 86p of the flange portion 86 does not eccentrically move with respect to the axis of the adjustment member 80. As a result, according to the present embodiment, the head module 46 can be accurately position-adjusted in the Y-axis direction with respect to the carriage 44.

[0045] According to the configuration of the inkjet image forming apparatus 10 according to the present embodiment, as described above, the plurality of leaf springs 88 bias the end face 72e in the Y-axis direction of the second positioning member 72 toward the outer peripheral surface 86p side of the flange portion 86 of the adjustment member 80. The coil spring 90 biases the outer peripheral surface 86p of the flange portion 86 toward the end face 72e side in the Y-axis direction of the second positioning member 72. Therefore, the contact between the outer peripheral surface 86p of the flange portion 86 and the end face 72e of the second positioning member 72 can be stably maintained. Accordingly, according to the present embodiment, the head module 46 can be positioned and adjusted with high precision and stability in the Y-axis direction with respect to the carriage 44.

[0046] According to the configuration of the inkjet image forming apparatus 10 according to the present embodiment, as described above, the movement of the head module 46 in the Y-axis direction is converted into a rotational movement centered on the first positioning pin 74. Therefore, according to the present embodiment, the inclination of the head module 46 with respect to the X-axis direction can be adjusted with high precision.

[0047] According to the configuration of the inkjet image forming apparatus 10 according to the present embodiment, the end face 72e in the Y-axis direction of the second positioning member 72 serves as the abutted portion on the head module 46 side. Therefore, the abutted portion on the head module 46 side can be machined with high precision into an inclined surface inclined with respect to the Y-axis direction. Accordingly, according to the present embodiment, the head module 46 can be positioned and adjusted with higher precision in the Y-axis direction with respect to the carriage 44.

[0048] According to the configuration of the inkjet image forming apparatus 10 according to the present embodiment, as described above, the second positioning hole of the second positioning member 72 extends in the X-axis direction. Therefore, during the rotational movement of the head module 46, the second positioning pin 76 moves in the X-axis direction along the second positioning hole 72h of the second positioning member 72. Accordingly, according to the present embodiment, the inclination of the head module 46 with respect to the X-axis direction can be adjusted stably and with high precision.

[0049] According to the configuration of the inkjet image forming apparatus 10 according to the present embodiment, when the outer peripheral surface 86p of the flange portion 86 is an R surface or an edge, the hardness of the end surface 72e in the Y-axis direction of the second positioning member 72 is made higher than the hardness of the outer peripheral surface 86p of the flange portion 86. Therefore, according to the present embodiment, it is possible to suppress wear and the like of the end surface 72e in the Y-axis direction of the second positioning member 72, which is the contact portion on the head module 46 side.

[0050] According to the configuration of the inkjet image forming apparatus 10 according to the present embodiment, as described above, the adjustment member 80 has a fitting portion 84 that is fitted into the fitting hole 78h of the carriage 44 so as to be movable in the Z-axis direction. Therefore, it is possible to suppress the runout during the movement of the adjustment member 80 in the Z-axis direction. In particular, when the distance in the Z-axis direction between the outer peripheral surface 86p of the flange portion 86 and the fitting portion 84 is shorter than the distance in the Z-axis direction between the outer peripheral surface 86p of the flange portion 86 and the screw portion 82, it is possible to sufficiently suppress the runout during the movement of the adjustment member 80 in the Z-axis direction. Thereby, according to the present embodiment, the head module 46 can be positioned with higher accuracy in the Y-axis direction with respect to the carriage 44.

[0051] According to the configuration of the inkjet image forming apparatus 10 according to the present embodiment, as described above, the movement amount of the head module 46 in the Y-axis direction is smaller than the movement amount of the adjustment member 80 in the Z-axis direction. Therefore, according to the present embodiment, the head module 46 can be positioned with high accuracy and easily in the Y-axis direction with respect to the carriage 44.

[0052] According to the configuration of the inkjet image forming apparatus 10 according to the present embodiment, as described above, the movement amount of the head module 46 in the Y-axis direction is proportional to the movement amount of the adjustment member 80 in the Z-axis direction. Therefore, according to the present embodiment, the head module 46 can be positioned with high accuracy and easily in the Y-axis direction with respect to the carriage 44.

[0053] According to the configuration of the inkjet image forming apparatus 10 according to the present embodiment, the pressing unit 92 presses the head module 46 toward the carriage 44 by an elastic force. Therefore, according to the present embodiment, displacement of the head module 46 with respect to the carriage 44 can be suppressed.

[0054] As described above, the present embodiment has been specifically described, but the present invention is not limited to the specific embodiments described above. Various modifications and changes can be made to the specific examples described in the above embodiments within the scope of the gist of the present invention described in the claims.

Industrial Applicability

[0055] The present invention is useful as an inkjet image forming apparatus capable of highly accurately adjusting the position of a head module in a first direction with respect to a mounting base.

Explanation of Signs

[0056] 10 Inkjet image forming apparatus 12 Apparatus main body 14 Center frame 16 First side frame 18 Second side frame 20 Paper feeding unit 22 Paper feeding tray 24 Conveying unit 26 Support roller 28 Belt 30 Image forming unit 32 Image forming drum 34 Delivery unit 36 Swing arm 38 Delivery drum 40 Medium heating unit 42 Head unit 44 Carriage (mounting base) 44h Through hole 46 Head module 48 Fixing unit 50 Delivery part 52 Support roller 54 Belt 56 Delivery Drum 58 Paper Discharge Unit 60 Paper Discharge Tray 62 Module Base 64 Inkjet Head 66 Support Member 68 Head Chip 68n Nozzle 70 First Positioning Member 70h First Positioning Hole 72 Second Positioning Member 72h Second Positioning Hole 72e End Face in Y - Axis Direction (Contacted Portion) 74 First Positioning Pin 76 Second Positioning Pin 78 Block Body 78b Screw Hole 78h Fitting Hole 80 Adjusting Member 82 Screw Portion 84 Fitting Portion 86 Flange Portion 86p Outer Peripheral Surface (Contact Portion) 88 Leaf Spring (First Biasing Member) 90 Coil Spring (Second Biasing Member) 92 Pressing Unit 94 Screw Member 96 Head 98 Movable Ring 100 Coil Spring P Recording Medium

Claims

1. A head module provided on a mounting base so as to be positionally adjustable in a first direction, a contact portion having a contact portion that is provided on the mounting base so as to be movable in a second direction intersecting the first direction and contacts the contact portion on the head module side, and a adjusting member for adjusting the position of the head module in the first direction; a first biasing member that biases the contact portion toward the contact portion side, at least one of the contact portion and the contact portion is an inclined surface inclined with respect to the second direction so that the movement of the adjusting member in the second direction is converted into the movement of the head module in the first direction, An inkjet image forming apparatus.

2. further comprising a second biasing member that biases the contact portion toward the contact portion side, The inkjet image forming apparatus according to claim 1.

3. The first direction is a sub-scanning direction, The inkjet image forming apparatus according to claim 1.

4. The head module has a first positioning pin that engages with a first positioning hole provided in the mounting base, The movement of the head module in the sub-scanning direction is converted into a rotational movement about the first positioning pin, The inkjet image forming apparatus according to claim 3.

5. further comprising a positioning member that is provided on the mounting base so as to be movable in the sub-scanning direction and has a second positioning hole, The head module has a second positioning pin that engages with the second positioning hole of the positioning member, A part of the positioning member is the contact portion, The inkjet image forming apparatus according to claim 4.

6. The second positioning hole is a long hole extending in the main scanning direction, The inkjet image forming apparatus according to claim 5.

7. The contact portion is an inclined surface inclined with respect to the second direction, The contact portion is an inclined surface, an R surface, or an edge inclined in a direction opposite to the inclined surface of the contact portion, The inkjet image forming apparatus according to claim 1.

8. When the contact portion is an R surface or an edge, the hardness of the contact portion is higher than the hardness of the contact portion, The inkjet image forming apparatus according to claim 7.

9. The adjusting member has a screw portion that screws into a screw hole provided in the mounting base, and moves in the second direction by a rotational operation of a tool connected from one side or the other side in the second direction, The inkjet image forming apparatus according to claim 1.

10. The adjustment member has a fitting portion that is movably fitted in the fitting hole provided in the mounting base in the second direction. The inkjet image forming apparatus according to claim 9.

11. The distance in the second direction between the contact portion and the fitting portion is shorter than the distance in the second direction between the contact portion and the screw portion. The inkjet image forming apparatus according to claim 10.

12. The adjustment member has an annular flange portion. The outer peripheral surface of the flange portion is the contact portion. The inkjet image forming apparatus according to claim 1.

13. The amount of movement of the head module in the first direction is smaller than the amount of movement of the adjustment member in the second direction. The inkjet image forming apparatus according to claim 1.

14. The inkjet image forming apparatus further includes a pressing unit that presses the head module toward the mounting base by an elastic force. The inkjet image forming apparatus according to claim 1.

15. The pressing force by the pressing unit is set to a pressing force that does not inhibit the position adjustment of the head module in the second direction, and the amount of movement of the head module in the first direction is proportional to the amount of movement of the adjustment member in the second direction. The inkjet image forming apparatus according to claim 14.

Images