Image forming apparatus

Abstract

To easily and stably attach a spacer to a substrate support member.SOLUTION: The substrate support member 8 is a sheet metal member to which the printed circuit board 7 is attached. The spacer 60 is disposed between the printed board 7 and the board support member 8. The substrate support member 8 forms a clamp hole 84a which is a through hole, and has a spacer engagement portion 84 which is an annular projection formed by burring. The spacer 60 has a first end part 601 formed with a clamp 61 having a flexible part 84a inserted into the clamp hole 61a and engaged with the spacer engaging part 84. Further, the spacer 60 has a second end portion 602 facing the surface of the printed circuit board 7 on the side opposite to the first end portion 601.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus having a printed circuit board fixed to a metal member. [Background technology]

[0002] The image forming apparatus includes a printing device that forms an image on a sheet, and further includes a printed circuit board on which a power supply circuit that supplies power to the printing device or a control circuit that controls the printing device is mounted.

[0003] The printed circuit board is fixed to a board support member, which is a sheet metal member, with a plurality of screws or the like. A spacer may be disposed between the printed circuit board and the board support member. The spacer prevents the printed circuit board from bending excessively.

[0004] For example, it is known that the spacer has a clamp formed at a first end of the spacer and an engagement groove formed at a second end of the spacer (see, for example, Patent Document 1). In this case, the clamp engages with the edge of the hole in the printed circuit board, and the engagement groove engages with the notch in the board support member. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Utility Model Application Publication No. 59-81074 Summary of the Invention [Problem to be solved by the invention]

[0006] When the spacer is attached to the printed circuit board, an attachment hole for the spacer is formed in the printed circuit board, and wiring patterns and mounted components are arranged in areas of the printed circuit board other than the attachment hole.

[0007] Therefore, when the spacer is attached to the printed circuit board, the size of the printed circuit board may become large.

[0008] Alternatively, the clamp of the spacer may be fastened to the substrate support member, but the metal plate constituting the substrate support member may not be thick enough to stably attach the clamp.

[0009] Furthermore, when the spacer is attached to the substrate support member by screws, the number of attachment steps increases.

[0010] SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus in which a spacer disposed between a printed circuit board and a board support member can be easily and stably attached to the board support member. [Means for solving the problem]

[0011] According to one aspect of the present invention, an image forming apparatus includes a printing device, a printed circuit board, a board support member, and a spacer. The printing device forms an image on a sheet. The printed circuit board is a board on which a power supply circuit for supplying power to the printing device or a control circuit for controlling the printing device is mounted. The board support member is a sheet metal member to which the printed circuit board is attached. The spacer is disposed between the printed circuit board and the board support member. The board support member has a clamp hole that is a through hole and a spacer engagement portion that is an annular protrusion formed by burring. The spacer has a first end portion on which a clamp is formed that is inserted into the clamp hole and has a flexible portion that engages with the spacer engagement portion. The spacer further has a second end portion opposite the first end portion and facing the surface of the printed circuit board. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide an image forming apparatus in which a spacer disposed between a printed circuit board and a board support member can be easily and stably attached to the board support member. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram illustrating the configuration of an image forming apparatus according to an embodiment. [Figure 2] FIG. 2 is a plan view of a substrate support structure in the image forming apparatus according to the embodiment. [Figure 3] FIG. 3 is a plan view of a portion of a substrate support member in a substrate support structure in an image forming apparatus according to an embodiment. [Figure 4] FIG. 4 is a cross-sectional view of the periphery of one of the plurality of substrate fixing portions in the substrate support structure of the image forming apparatus according to the embodiment. [Figure 5] FIG. 5 is an exploded cross-sectional view of the peripheral portion of one of the plurality of substrate fixing portions in the substrate support structure of the image forming apparatus according to the embodiment. [Figure 6] FIG. 6 is a cross-sectional view of a peripheral portion of a spacer in a substrate support structure in an image forming apparatus according to an embodiment. [Figure 7] FIG. 7 is an exploded cross-sectional view of a peripheral portion of a spacer in a substrate support structure in an image forming apparatus according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the following embodiment is an example of the present invention, and does not limit the technical scope of the present invention.

[0015] The image forming apparatus 10 according to the embodiment is capable of executing a print process for forming an image on a sheet 9.

[0016] [Configuration of image forming apparatus 10] 1, the image forming apparatus 10 includes a sheet transport mechanism 3 and a printing device 4. In this embodiment, the image forming apparatus 10 also includes an image reading device 2 that reads an image from a document 9x.

[0017] The sheet transport mechanism 3 transports the sheet 9 stored in the sheet storage unit 30 along a transport path 300. The sheet transport mechanism 3 includes a sheet feeding mechanism 31 and a plurality of pairs of transport rollers 32.

[0018] The sheet feeding mechanism 31 sends out the sheet 9 from the sheet storage unit 30 to the conveying path 300. A plurality of pairs of conveying rollers 32 convey the sheet 9 along the conveying path 300.

[0019] The printing device 4 forms an image on a sheet 9 transported along a transport path 300. One of the plurality of transport roller pairs 32 ejects the sheet 9 with the image formed thereon from the transport path 300.

[0020] 1, the printing device 4 performs the printing process by electrophotography. In this case, the printing device 4 includes an optical scanning device 40, one or more image forming units 4x, a transfer device 44, and a fixing device 45.

[0021] The image forming unit 4x includes a photoconductor 41, a charging device 42, and a developing device 43. The charging device 42 charges the surface of the photoconductor 41. The optical scanning device 40 forms an electrostatic latent image on the surface of the photoconductor 41 by scanning a beam of light across the charged surface of the photoconductor 41.

[0022] The developing device 43 develops the electrostatic latent image into a toner image by supplying toner to the surface of the photoreceptor 41. The photoreceptor 41 is an image carrier that carries the toner image.

[0023] The transfer device 44 transfers the toner image on the surface of the photoreceptor 41 to the sheet 9. The fixing device 45 fixes the toner image to the sheet 9 by applying heat and pressure to the toner image transferred to the sheet 9.

[0024] 1, the printing apparatus 4 is a tandem color printing apparatus, and therefore includes a plurality of image forming units 4x corresponding to a plurality of developing colors.

[0025] The transfer device 44 includes an intermediate transfer belt 441, a plurality of primary transfer devices 442 and a secondary transfer device 443 corresponding to the plurality of image forming units 4x.

[0026] Each primary transfer device 442 transfers the toner image on the photoconductor 41 of each image forming unit 4x onto the surface of the intermediate transfer belt 441. The secondary transfer device 443 transfers the toner image on the surface of the intermediate transfer belt 441 onto the sheet 9.

[0027] The printing device 4 may be a device that forms an image on the sheet 9 by a method other than the electrophotographic method. For example, the printing device 4 may be a device that forms an image on the sheet 9 by an inkjet method.

[0028] The image forming apparatus 10 further includes a control device 5 that controls the image reading device 2, the sheet conveying mechanism 3, and the printing device 4. The control device 5 executes various data processing operations and controls various devices in the image forming apparatus 10.

[0029] [Substrate support structure 6] The control device 5 includes a board support structure 6 including a printed circuit board 7 and a board support member 8 on which the printed circuit board 7 is mounted (see FIGS. 1 and 2).

[0030] The printed circuit board 7 is a board on which a circuit 71 including one or both of a power supply circuit and a control circuit is mounted. In addition to pattern wiring, the circuit 71 includes mounted components such as a connector 72 and an IC 73. The power supply circuit supplies power to the printing device 4. The control circuit controls the printing device 4.

[0031] The board support member 8 is a sheet metal member. The board support structure 6 includes a plurality of screws 80 that secure the printed circuit board 7 to the board support member 8. In this embodiment, four screws 80 secure the four corners of the generally rectangular printed circuit board 7 to the board support member 8 (see FIG. 2).

[0032] The board support structure 6 further comprises a spacer 60 disposed between the printed circuit board 7 and the board support member 8 (see FIGS. 2, 3, 6 and 7).

[0033] The spacer 60 prevents excessive bending of the printed circuit board 7. In this embodiment, the spacer 60 has a clamp 61 (FIGS. 6 and 7).

[0034] When the spacer 60 is attached to the printed circuit board 7, attachment holes for the spacer 60 are formed in the printed circuit board 7. The wiring pattern and the mounted components are arranged in areas of the printed circuit board 7 other than the attachment holes.

[0035] Therefore, when the spacer 60 is attached to the printed circuit board 7, the size of the printed circuit board 7 may become large.

[0036] Alternatively, it is conceivable that the clamps 61 of the spacers 60 are fastened to the substrate support member 8. However, there are cases where the metal plate that constitutes the substrate support member 8 does not have a sufficient thickness for the clamps 61 to be stably attached.

[0037] Furthermore, if the spacer 60 is attached to the substrate support member 8 by screws, the number of attachment steps increases.

[0038] The board support structure 6 has a configuration that allows the spacer 60, which is disposed between the printed circuit board 7 and the board support member 8, to be easily and stably attached to the board support member 8. The configuration will be described below.

[0039] The substrate support member 8 has a plurality of substrate fixing portions 81 and a plurality of screw fitting portions 82 formed on the plurality of substrate fixing portions 81 (see FIG. 3).

[0040] Each of the board fixing portions 81 is a raised portion formed by drawing so as to face a specific surface 7x of the printed circuit board 7 (see FIGS. 4 and 5). Each of the screw fitting portions 82 is formed at the top of each of the board fixing portions 81.

[0041] The plurality of screw fitting portions 82 are a plurality of annular protrusions formed by burring (see FIGS. 3 to 5). In this embodiment, each of the screw fitting portions 82 protrudes to the side opposite to the printed circuit board 7 side.

[0042] The plurality of screw fitting portions 82 form a plurality of screw holes 82a which are holes that respectively penetrate the plurality of substrate fixing portions 81. A screw thread 82b is formed on the inner surface of each of the screw fitting portions 82 (see FIGS. 4 and 5).

[0043] In this embodiment, the substrate support member 8 has four substrate fixing portions 81 and four screw fitting portions 82 corresponding to the four screws 80 .

[0044] The four screws 80 are inserted into the four through holes 70 formed in the four corners of the printed circuit board 7 and are threaded into the four screw fitting portions 82. In this way, the four screws 80 fix the printed circuit board 7 to the four board fixing portions 81.

[0045] The circuit 71 of the printed circuit board 7 has a ground pattern 71a formed on at least some of the four contact portions 7a that come into contact with the four board fixing portions 81 of the printed circuit board 7 (see FIG. 2).

[0046] In this embodiment, the four contact portions 7a are four corner portions on the specific surface 7x of the printed circuit board 7. In the example shown in Fig. 2, the ground pattern 71a is formed on the four contact portions 7a.

[0047] The printed circuit board 7 is fixed to the four board fixing portions 81 with the four screws 80, and the board support member 8 functions as a ground conductor, so that no grounding wire is required.

[0048] The board support member 8 has a spacer engagement portion 84, which is a ring-shaped protrusion formed by burring (see FIGS. 3, 6, and 7). The spacer engagement portion 84 has a clamp hole 84a, which is a through hole, formed inside the spacer engagement portion 84. In this embodiment, the spacer engagement portion 84 protrudes to the side opposite the printed circuit board 7 side. However, the spacer engagement portion 84 may also protrude to the printed circuit board 7 side.

[0049] The spacer 60 has a first end 601 where the clamp 61 is formed, and a second end 602 opposite the first end 601 (see FIGS. 6 and 7). The clamp 61 has a flexible portion 61a that is inserted into the clamp hole 84a and engages with the spacer engaging portion 84.

[0050] When the clamp 61 is inserted into the clamp hole 84a, the flexible portion 61a deforms so that its width narrows as it passes through the clamp hole 84a, and then returns to its original shape when it passes through the clamp hole 84a, thereby engaging with the spacer engagement portion 84.

[0051] The spacer engagement portion 84 is formed with a height necessary and sufficient for stable attachment of the clamp 61. Therefore, regardless of the thickness of the metal plate that constitutes the substrate support member 8, the clamp 61 can be stably fastened to the spacer engagement portion 84.

[0052] The second end 602 of the spacer 60 faces the specific surface 7x of the printed circuit board 7. The specific surface 7x is one of two surfaces of the printed circuit board 7. The distance between the second end 602 of the spacer 60 and the specific surface 7x of the printed circuit board 7 is designed according to the amount of deflection that the printed circuit board 7 can tolerate.

[0053] If necessary, a configuration may be adopted in which the second end 602 of the spacer 60 contacts a specific surface 7x of the printed circuit board 7.

[0054] In this embodiment, the board support member 8 has a spacer mounting portion 83, which is a raised portion formed by drawing so as to face the specific surface 7x of the printed board 7 (see FIGS. 3, 6, and 7). The spacer engaging portion 84 is formed on the top of the spacer mounting portion 83.

[0055] 6 and 7, the spacer mounting portions 83 are raised portions that are shorter than the respective substrate fixing portions 81. In other words, the respective substrate fixing portions 81 are raised portions that are taller than the spacer mounting portions 83.

[0056] By employing the substrate support structure 6, the spacer 60 can be attached to the substrate support member 8 easily and stably.

[0057] Furthermore, since the spacer engagement portion 84 is formed in the spacer mounting portion 83 formed by drawing, at least a portion of the clamp 61 fits inside the spacer mounting portion 83. This reduces the height that the clamp 61 protrudes from the substrate support member 8, increasing the degree of freedom in arranging the substrate support member 8.

[0058] Furthermore, the spacer mounting portion 83 formed by drawing has higher dimensional accuracy and strength than the portion formed by cutting and bending a part of the metal plate, so the spacer 60 is stably held with high positional accuracy.

[0059] Furthermore, it is possible to form a plurality of substrate fixing portions 81 and one or more spacer mounting portions 83 in a single drawing process, which makes it easy to process the substrate support member 8.

[0060] [Notes on the Invention] The following is a summary of the invention extracted from the above-described embodiment. Note that the configurations and processing functions described in the following supplementary notes can be selected and combined as desired.

[0061] <Appendix 1> a printing device for forming an image on a sheet; a printed circuit board on which a power supply circuit for supplying power to the printing device or a control circuit for controlling the printing device is mounted; a board support member which is a metal plate member to which the printed circuit board is attached; a spacer disposed between the printed circuit board and the board support member, the substrate support member has a clamp hole that is a through hole, and a spacer engagement portion that is an annular protrusion formed by burring; The spacer is a first end portion formed with a clamp having a flexible portion that is inserted into the clamp hole and engages with the spacer engaging portion; a second end portion opposite the first end portion and facing the surface of the printed circuit board.

[0062] <Appendix 2> the board support member has a spacer mounting portion which is a raised portion formed by drawing so as to face the printed board; 2. The image forming apparatus according to claim 1, wherein the spacer engagement portion is formed in the spacer mounting portion.

[0063] <Appendix 3> a plurality of screws for fixing the printed circuit board to the board support member; The substrate support member includes: a plurality of board fixing portions, which are raised portions formed by drawing so as to face the printed board; a plurality of screw holes that are holes that penetrate the plurality of substrate fixing portions, and a plurality of screw fitting portions that are a plurality of annular protrusions formed by burring, each having a screw thread formed on an inner surface thereof; The image forming apparatus described in Appendix 2, wherein the plurality of screws are inserted into a plurality of through holes formed in the printed circuit board and screwed into the plurality of screw engagement portions, thereby fixing the printed circuit board to the plurality of board fixing portions.

[0064] <Appendix 4> The image forming apparatus according to claim 3, wherein the printed circuit board has a ground pattern formed on at least some of a plurality of contact portions that contact the plurality of board fixing portions on the printed circuit board. [Explanation of symbols]

[0065] 4: Printing device 6: Board support structure 7: Printed circuit board 7a: Contact part 8: Substrate support member 10: Image forming device 60: Spacer 61: Clamp 61a:Flexible part 70:Through hole 71: Circuit 71a: Ground pattern 80: Screw 81: Board fixing part 82: Threaded fitting 82a: screw hole 82b: Thread 83: Spacer mounting part 84: Spacer engagement part 84a: Clamp hole 601: First end of spacer 602: Second end of spacer

Claims

1. a printing device for forming an image on a sheet; a printed circuit board on which a power supply circuit for supplying power to the printing device or a control circuit for controlling the printing device is mounted; a board support member which is a metal plate member to which the printed circuit board is attached; a spacer disposed between the printed circuit board and the board support member, the substrate support member has a clamp hole that is a through hole, and a spacer engagement portion that is an annular protrusion formed by burring; The spacer is a first end portion having a clamp formed thereon, the clamp portion having a flexible portion that is inserted into the clamp hole and engages with the spacer engaging portion; a second end portion opposite the first end portion and facing the surface of the printed circuit board.

2. the board support member has a spacer mounting portion which is a raised portion formed by drawing so as to face the printed board; 2. The image forming apparatus according to claim 1, wherein the spacer engaging portion is formed in the spacer mounting portion.

3. a plurality of screws for fixing the printed circuit board to the board support member; The substrate support member includes: a plurality of board fixing portions, which are raised portions formed by drawing so as to face the printed board; a plurality of screw holes that are holes that penetrate the plurality of substrate fixing portions, and a plurality of screw fitting portions that are a plurality of annular protrusions formed by burring, each having a screw thread formed on an inner surface thereof; 3. The image forming apparatus according to claim 2, wherein the plurality of screws are inserted into a plurality of through holes formed in the printed circuit board and then screwed into the plurality of screw engagement portions, thereby fixing the printed circuit board to the plurality of board fixing portions.

4. 4. The image forming apparatus according to claim 3, wherein the printed circuit board has a ground pattern formed on at least some of a plurality of contact portions that come into contact with the plurality of board fixing portions of the printed circuit board.

Images