Image forming apparatus

Abstract

To simplify a dustproof structure in a wiring route of a wire harness connected to an electronic board within an optical scanning unit.SOLUTION: A cover part 102 closes a first opening 101a of a main box part 101. A second opening 503 is formed in a unit housing 50 to expose to the outside a connector 520 mounted on an electronic board 52. The unit housing 50 has a convex inner frame part 501 and a wiring part 504. The convex inner frame part 501 projects from an outer surface of the unit housing 50 and encloses the periphery of the second opening 503. The cover part 102 projects from an inner surface of the cover part 102 and has a convex outer frame part 103 that encloses the periphery of the convex inner frame part 501. A top part of the convex inner frame part 501 is formed along an inner side portion of the convex outer frame part 103 on the inner surface of the cover part 102. A top part of the convex outer frame part 103 is formed along an outer side portion of the convex inner frame part 501 on the outer surface of the unit housing 50.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to an image forming apparatus including an optical scanning unit.

Background Art

[0002] An electrophotographic image forming apparatus includes an optical scanning unit that forms an electrostatic latent image on the surface of a photoreceptor. The optical scanning unit includes an optical scanner such as a polygon mirror and other optical devices. Therefore, dust prevention measures for the optical scanning unit are important.

[0003] For example, it is known that a gap between a main housing and a cover portion constituting an optical box of the optical scanning unit is sealed by an elastic member (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, the optical scanning unit includes an electronic substrate on which a circuit for driving the optical scanner is mounted. The electronic substrate is connected to a control device by a wire harness.

[0006] Therefore, in the scanning unit, dust prevention measures are required in the wiring path of the wire harness. It is desired that a dust prevention structure for the wiring path of the wire harness be realized by a simple structure.

[0007] An object of the present invention is to provide an image forming apparatus capable of simplifying a dust prevention structure in a wiring path of a wire harness connected to an electronic substrate in an optical scanning unit.

Means for Solving the Problems

[0008] An image forming apparatus according to one aspect of the present invention includes a main housing, an optical scanning unit, and a wire harness. The main housing has a main box portion in which a first opening is formed and a cover portion attached to the main box portion and closing the first opening. The optical scanning unit includes a scanner, an electronic board on which a circuit and a connector for driving the scanner are mounted, and a unit housing that houses the scanner and the electronic board and has a second opening formed therein for exposing the connector to the outside, and is housed in the main box portion. The wire harness is connected to the connector of the electronic board and is wired in the main box portion. The unit housing has a convex inner frame portion and a wiring portion. The convex inner frame portion protrudes from the outer surface of the unit housing and surrounds the periphery of the second opening. The wiring portion forms a routing path for the wire harness extending from the inside to the outside of the convex inner frame portion. The cover portion has a convex outer frame portion that protrudes from the inner surface of the cover portion and surrounds the periphery of the convex inner frame portion. The top portion of the convex inner frame portion is formed along the inner side portion of the convex outer frame portion on the inner surface of the cover portion. The top portion of the convex outer frame portion is formed along the outer side portion of the convex inner frame portion on the outer surface of the unit housing.

Advantages of the Invention

[0009] According to the present invention, it is possible to provide an image forming apparatus capable of simplifying a dustproof structure in a wiring path of a wire harness connected to an electronic board in an optical scanning unit.

Brief Description of the Drawings

[0010]

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Figure 10

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments are an example of embodying the present invention and do not limit the technical scope of the present invention.

[0012] The image forming apparatus 10 according to the embodiment executes print processing by an electrophotographic method. The print processing is a process of forming an image on a sheet 9. The sheet 9 is an image forming medium such as paper or a sheet-like resin member.

[0013] The image forming apparatus 10 shown in FIG. 1 is a printer. The image forming apparatus 10 may be a copier, a facsimile apparatus, a multifunction machine, or the like.

[0014] [Configuration of Image Forming Apparatus 10] As shown in FIG. 1, the image forming apparatus 10 includes a main housing 1, a sheet conveyance device 3, a printing device 4, and a control device 8 housed in the main housing 1.

[0015] The sheet conveyance device 3 includes a sheet feeding mechanism 30 and a plurality of sets of conveyance roller pairs 31. The sheet feeding mechanism 30 feeds the sheet 9 housed in the sheet storage unit 2 to the conveyance path 300. The conveyance path 300 is a path through which the sheet 9 is conveyed.

[0016] The plurality of sets of conveyance roller pairs 31 rotate to convey the sheet 9 along the conveyance path 300. Further, the plurality of sets of conveyance roller pairs 31 discharge the sheet 9 on which an image is formed in the conveyance path 300 to the discharge tray 1x.

[0017] The printing device 4 includes an optical scanning unit 5, one or more image forming units 4x, a transfer device 44, and a fixing device 46.

[0018] In the present embodiment, the image forming apparatus 10 includes a tandem type printing device 4. Therefore, the printing device 4 includes a plurality of image forming units 4x corresponding to a plurality of developing colors.

[0019] Each of the image forming units 4x includes a drum-shaped photoreceptor 41, a charging device 42, a developing device 43, a drum cleaning device 45, and the like. That is, the printing device 4 includes a plurality of photoreceptors 41, a plurality of developing devices 43, and a plurality of drum cleaning devices 45 corresponding to a plurality of developing colors.

[0020] In each of the image forming units 4x, the photoreceptor 41 rotates, and the charging device 42 charges the surface of the photoreceptor 41. The optical scanning unit 5 scans a plurality of laser beams on the surface of each of the plurality of charged photoreceptors 41. Thereby, the optical scanning unit 5 forms an electrostatic latent image on the surface of each of the plurality of photoreceptors 41.

[0021] A plurality of developing devices 43 develop the electrostatic latent image into a toner image by supplying toner to the surfaces of the plurality of photoreceptors 41, respectively. The toner is a granular developer. The photoreceptor 41 is an example of an image carrier that rotates while carrying the toner image.

[0022] In the present embodiment, the printing apparatus 4 includes four image forming units 4x corresponding to the toner of four developing colors of yellow, cyan, magenta, and black. Therefore, the printing apparatus 4 includes four photoreceptors 41, four developing devices 43, and four drum cleaning devices 45.

[0023] Four toner images are formed on the surfaces of the four photoreceptors 41. The transfer device 44 transfers the four toner images from the four photoreceptors 41 to the sheet 9.

[0024] The transfer device 44 includes an intermediate transfer belt 441, four primary transfer devices 442 corresponding to the four image forming units 4x, a secondary transfer device 443, and a belt cleaning device 444.

[0025] The four primary transfer devices 442 transfer the toner images on the surfaces of the four photoreceptors 41 to the surface of the intermediate transfer belt 441. As a result, a color toner image in which the toner images of the four photoreceptors 41 are combined is formed on the surface of the intermediate transfer belt 441.

[0026] The secondary transfer device 443 transfers the color toner image formed on the intermediate transfer belt 441 to the sheet 9 at the transfer position of the conveyance path 300.

[0027] The fixing device 46 pressurizes the color toner image transferred to the sheet 9 while heating it. Thereby, the fixing device 46 fixes the color toner image to the sheet 9.

[0028] Each of the drum cleaning devices 45 removes the waste toner remaining on the surface of each of the photoreceptors 41. The belt cleaning device 444 removes the waste toner remaining on the intermediate transfer belt 441.

[0029] In addition, when the image forming apparatus 10 is a monochrome image forming apparatus, the printing apparatus 4 has one image forming unit 4x. In this case, the primary transfer device 442 transfers the electrostatic latent image from the photoreceptor 41 to the sheet 9.

[0030] As shown in FIGS. ② and ③, the optical scanning unit 5 includes a unit housing 50, a plurality of light sources (not shown), an optical scanner 51, an electronic substrate 52, one or more main lenses 53, a plurality of mirrors 54, and a plurality of sub-lenses 55.

[0031] The unit housing 50 is a molded member of synthetic resin. The unit housing 50 houses the plurality of light sources, the optical scanner 51, and the electronic substrate 52.

[0032] The plurality of light sources are laser light sources that each emit laser light. The optical scanner 51 scans the plurality of laser lights emitted from the plurality of light sources.

[0033] In the present embodiment, the optical scanner 51 is a polygon mirror. The polygon mirror has a plurality of mirrors arranged in a regular polygon shape in the circumferential direction. The polygon mirror rotates by being driven by a polygon motor 510 (see FIG. ②).

[0034] Note that a galvanometer mirror or a MEMS mirror (Micro Electro Mechanical Systems mirror) may be adopted as the optical scanner 51.

[0035] A circuit for driving the polygon motor 510 is executed on the electronic substrate 52. That is, a circuit for driving the optical scanner 51 is executed on the electronic substrate 52. Each of the main lenses 53 and each of the sub-lenses 55 is an fθ lens.

[0036] Note: Here, ② and ③ in the translation of should be replaced with the actual figure numbers in English (Figure 2 and Figure 3). The above is a translation based on the provided text, and you may need to adjust it according to the actual situation.One or more main lenses 53, a plurality of mirrors 54, and a plurality of sub - lenses 55 are arranged within the unit housing 50. The plurality of laser lights pass through the main lens 53 and the plurality of sub - lenses 55 and are reflected by the plurality of mirrors 54, and then scanned on the surfaces of the plurality of photoreceptors 41.

[0037] The control device 8 controls the sheet conveyance device 3 and the printing device 4. For example, the control device 8 controls the formation of the electrostatic latent image on the surfaces of the plurality of photoreceptors 41 by controlling the plurality of light sources and the polygon motor 510 in the optical scanning unit 5.

[0038] The optical scanning unit 5 includes optical devices such as an optical scanner 51, a main lens 53, and a plurality of mirrors 54. Therefore, dust prevention measures for the optical scanning unit 5 are important.

[0039] Incidentally, the optical scanning unit 5 includes an electronic substrate 52 on which a circuit for driving the optical scanner 51 is mounted. The electronic substrate 52 is connected to the control device 8 by a wire harness 6 (see FIGS. 1 and 6).

[0040] Therefore, in the optical scanning unit 5, dust prevention measures are required in the wiring path of the wire harness 6. It is desired that the dust prevention structure of the wiring path of the wire harness 6 be realized by a simple structure.

[0041] Hereinafter, a configuration for simplifying the dust prevention structure in the wiring path of the wire harness 6 connected to the electronic substrate 52 in the optical scanning unit 5 will be described.

[0042] The main housing 1 includes a main box portion 101 in which a first opening 101a is formed, and a cover portion 102 attached to the main box portion 101. The cover portion 102 closes the first opening 101a by being attached to the main box portion 101. The optical scanning unit 5 is housed within the main box portion 101 (see FIG. 4).

[0043] In this embodiment, the first opening 101a opens upward the main box portion 101 (see Fig. 4). The cover portion 102 includes a discharge tray 1x for receiving the sheet 9 discharged from the main housing 1 (see Fig. 4). The discharge tray 1x is formed on the outer surface 102a of the cover portion 102.

[0044] In the optical scanning unit 5, a connector 520 is mounted on an electronic substrate 52 (see Figs. 5, 6, and 9). Further, a second opening 503 for exposing the connector to the outside of the unit housing 50 is formed in the unit housing 50 (see Figs. 5, 6, 9, and 10).

[0045] In this embodiment, the unit housing 50 further has a frame inner recess 502 (see Figs. 5 and 6). The frame inner recess 502 is a portion recessed more than the outer portion of the convex inner frame portion 501 inside the convex inner frame portion 501 on the outer surface of the unit housing 50.

[0046] The second opening 503 of the unit housing 50 is formed on the bottom surface of the frame inner recess 502 (see Figs. 5 and 6). The connector 520 of the electronic substrate 52 penetrates the second opening 503 (see Figs. 5, 6, and 9).

[0047] The wire harness 6 is connected to the connector 520 of the electronic substrate 52 and is wired inside the main box portion 101. In this embodiment, the wire harness 6 is connected to the connector 520 of the electronic substrate 52 and the control device 8 inside the main box portion 101.

[0048] The unit housing 50 has a convex inner frame portion 501 and a wiring portion 504 (see Figs. 5, 6, 9, and 10). The convex inner frame portion 501 protrudes from the outer surface of the unit housing 50 and surrounds the periphery of the second opening 503. The wiring portion 504 is a portion forming a lead-out path of the wire harness 6 extending from the inside to the outside of the convex inner frame portion 501.

[0049] The cover part 102 has a convex outer frame part 103 (see FIGS. 7 to 9). The convex outer frame part 103 protrudes from the inner surface 102b of the cover part 102. In a state where the cover part 102 closes the first opening 101a of the main box part 101, the convex outer frame part 103 surrounds the periphery of the convex inner frame part 501 of the unit housing 50 (see FIGS. 9 and 10).

[0050] The top part of the convex inner frame part 501 is formed along the inner part of the convex outer frame part 103 on the inner surface 102b of the cover part 102 (see FIG. 9). The top part of the convex outer frame part 103 is formed along the outer part of the convex inner frame part 501 on the outer surface of the unit housing 50 (see FIG. 9).

[0051] In the example shown in FIG. 9, a frame outer recess 506, which is a recess into which the top part of the convex outer frame part 103 is inserted, is formed on the outer surface of the unit housing 50.

[0052] In the present embodiment, the wiring part 504 is in a groove shape that is recessed more than the outer part of the convex inner frame part 501 on the outer surface of the unit housing 50 (see FIG. 6). Thereby, the top part of the convex outer frame part 103 is arranged across a pair of edges of the groove-shaped wiring part 504.

[0053] A pair of opposing walls 501a, which are part of the convex inner frame part 501, are formed along a pair of edges of the groove-shaped wiring part 504 (see FIGS. 6 and 10).

[0054] The unit housing 50 further has a detachment prevention part 505 that prevents the wire harness 6 from detaching from the wiring part 504 (see FIGS. 5, 6, and 10). The detachment prevention part 505 is formed to project onto the wiring part 504 from a pair of edges of the groove-shaped wiring part 504.

[0055] By adopting the convex inner frame part 501 and the convex outer frame part 103, the air passage from the region outside the convex outer frame part 103 in the main housing 1 to the region inside the convex inner frame part 501 including the second opening 503 is narrowed. As a result, the dustproof effect of the unit housing 50 is enhanced.

[0056] By adopting the frame inner concave portion 502, the bottom surface of the frame inner concave portion 502 is arranged close to the electronic substrate 52, and the gap communicating between the inside and the outside of the unit housing 50 through the second opening 503 is narrowed. As a result, the dustproof effect of the unit housing 50 is further enhanced.

[0057] Note that the convex inner frame portion 501 is not in contact with the cover portion 102. Similarly, the convex outer frame portion 103 is not in contact with the unit housing 50. Therefore, the vibration of the cover portion 102 when the sheet 9 is discharged onto the discharge tray 1x does not directly propagate to the optical scanning unit 5.

[0058] By adopting the optical scanning unit 5 and the cover portion 102, a dustproof structure for the wiring path of the wire harness 6 is realized without using an elastic member such as a rubber member or a foamed member. Therefore, the dustproof structure of the wiring path of the wire harness 6 is simplified.

[0059] [Supplementary Note of the Invention] Hereinafter, the outline of the invention extracted from the above-described embodiment will be appended. Note that each configuration and each processing function described in the following supplementary note can be arbitrarily combined by selection.

[0060] [Supplementary Note 1] A main housing having a main box portion in which a first opening is formed and a cover portion attached to the main box portion for closing the first opening, An optical scanning unit, an electronic substrate on which a circuit and a connector for driving the optical scanning unit are mounted, and a unit housing that houses the optical scanning unit and the electronic substrate and has a second opening for exposing the connector to the outside, A wire harness connected to the connector of the electronic substrate and wired in the main box portion, The unit housing, A convex inner frame portion protruding from the outer surface of the unit housing and surrounding the periphery of the second opening, A wiring portion that forms a drawing path of the wire harness extending from the inside to the outside of the convex inner frame portion, The cover part has a convex outer frame part that protrudes from the inner surface of the cover part and surrounds the periphery of the convex inner frame part. The top part of the convex inner frame part is formed along the inner side part of the convex outer frame part on the inner surface of the cover part. An image forming apparatus, wherein the top part of the convex outer frame part is formed along the outer side part of the convex inner frame part on the outer surface of the unit housing.

[0061] <Appendix 2> The wiring part is in a groove shape that is recessed more than the outer side part of the convex inner frame part on the outer surface of the unit housing, and is the image forming apparatus according to Appendix 1.

[0062] <Appendix 3> The unit housing has a detachment prevention part that protrudes onto the wiring part from a pair of edges of the groove-shaped wiring part to prevent detachment of the wire harness from the wiring part, and is the image forming apparatus according to Appendix 2.

[0063] <Appendix 4> A part of the convex inner frame part is formed along a pair of edges of the groove-shaped wiring part, and is the image forming apparatus according to Appendix 2 or Appendix 3.

[0064] <Appendix 5> The unit housing has a recessed part inside the frame that is recessed more than the outer part outside the convex inner frame part on the outer surface of the unit housing. The second opening is formed on the bottom surface of the recessed part inside the frame. The connector of the electronic substrate penetrates through the second opening, and is the image forming apparatus according to any one of Appendix 1 to Appendix 4.

[0065] <Appendix 6> The cover part includes a discharge tray for receiving a sheet discharged from the main housing, and is the image forming apparatus according to any one of Appendix 1 to Appendix 5.

Explanation of Signs

[0066] 1: Main housing 1x: Discharge tray 4: Printing device 4x: Image forming unit 5: Optical scanning unit 6: Wire harness 8: Control device 10: Image forming apparatus 50: Unit housing 51: Optical scanner 52: Electronic substrate 101: Main box part 101a: First opening 102: Cover part 103: Convex outer frame part 501: Convex inner frame part 501a: Opposing wall 502: Concave part inside the frame 503: Second opening 504: Wiring part 505: Anti-disengagement part 506: Concave part outside the frame 520: Connector

Claims

1. A main housing having a main box portion in which a first opening is formed and a cover portion attached to the main box portion to close the first opening, An optical scanning unit, an electronic substrate on which a circuit and a connector for driving the optical scanning unit are mounted, and a unit housing that houses the optical scanning unit and the electronic substrate and has a second opening formed to expose the connector to the outside, and an optical scanning unit housed in the main box portion, A wire harness connected to the connector of the electronic substrate and wired in the main box portion, The unit housing, A convex inner frame portion protruding from the outer surface of the unit housing and surrounding the periphery of the second opening, A wiring portion forming a routing path for the wire harness extending from the inside to the outside of the convex inner frame portion, The cover portion has a convex outer frame portion protruding from the inner surface of the cover portion and surrounding the periphery of the convex inner frame portion, The top portion of the convex inner frame portion is formed along the inner side portion of the convex outer frame portion on the inner surface of the cover portion, The top portion of the convex outer frame portion is formed along the outer side portion of the convex inner frame portion on the outer surface of the unit housing. An image forming apparatus.

2. The wiring portion is in a groove shape recessed more than the outer side portion of the convex inner frame portion on the outer surface of the unit housing. The image forming apparatus according to claim 1.

3. The unit housing has a detachment prevention portion that protrudes onto the wiring portion from a pair of edges of the groove-shaped wiring portion to prevent detachment of the wire harness from the wiring portion. The image forming apparatus according to claim 2.

4. A part of the convex inner frame portion is formed along a pair of edges of the groove-shaped wiring portion. The image forming apparatus according to claim 2 or claim 3.

5. The unit housing has an inner frame recess that is recessed more than the outer portion outside the convex inner frame portion on the inner side of the convex inner frame portion on the outer surface of the unit housing, The second opening is formed in the bottom surface of the inner frame recess, The connector of the electronic substrate penetrates the second opening. The image forming apparatus according to any one of claims 1 to 3.

6. The cover portion includes a discharge tray for receiving a sheet discharged from the main housing. The image forming apparatus according to any one of claims 1 to 3.

Images