Optical scanning device and image forming apparatus including the same

Abstract

The invention provides an optical scanning device and an image forming apparatus including the same. The optical scanning device includes a scanning optical system, a frame, and a pressing holding member. The housing accommodates the scanning optical system therein, and has a holding section that holds an optical element constituting the scanning optical system. The pressing and holding member presses the optical element and holds the optical element in the holding portion. The pressing holding member has a main body portion and a pressing portion. The pressing part is connected to the main body part and presses the optical element held by the holding part toward the holding part. The frame body has a support part which is formed so as to face the holding part and supports the main body part. The support portion is disposed on the periphery of a through hole penetrating through the frame and has a support protrusion. The support protrusion protrudes from the outer surface and is in contact with the peripheral edge of the main body. The through hole is an emission port for emitting the laser light to the outside of the housing.

Description

Technical Field

[0001] The present invention relates to an optical scanning device that forms a latent image on a scanned surface by exposure scanning, and an image forming device such as a copier, printer, facsimile machine, and a multifunction machine thereof equipped with the optical scanning device. Background Art

[0002] Patent document 1 discloses a conventional optical scanning device. The optical scanning device includes a scanning optical system that scans laser light and guides it onto an image carrier, a frame, and a pressing and holding component. The surface of the image carrier is exposed to form an electrostatic latent image that attenuates the charge. The frame accommodates the scanning optical system inside and has a holding portion that holds an optical element constituting the scanning optical system. The pressing and holding component presses the optical element to hold the optical element in the holding portion. The frame has a supporting portion that is formed opposite to the holding portion and supports the pressing and holding component. The pressing and holding component is inserted into a through hole that penetrates the frame.

[0003] In the case of adopting the conventional technology, dust may enter the interior of the housing through the through hole. Therefore, there is a problem that a new component for blocking the through hole needs to be provided, which increases the manufacturing cost of the optical scanning device. Summary of the invention

[0004] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an optical scanning device capable of stably holding an optical element while suppressing an increase in manufacturing cost, and an image forming apparatus including the optical scanning device.

[0005] An optical scanning device according to one aspect of the present invention includes a scanning optical system, a frame, and a pressing and holding component, which forms an electrostatic latent image that attenuates charge by exposing the surface of an image carrier. The scanning optical system scans a laser and guides the laser onto the image carrier. The frame accommodates the scanning optical system inside and has a holding portion, which holds an optical element constituting the scanning optical system. The pressing and holding component presses the optical element and presses the optical element to hold the optical element on the holding portion. The pressing and holding component has a main body and a pressing portion. The pressing portion is connected to the main body and presses the optical element held by the holding portion toward the holding portion. The frame has a supporting portion, which is formed opposite to the holding portion and supports the main body. The supporting portion is arranged on the periphery of a through hole that passes through the frame, and has a supporting protrusion. The supporting protrusion protrudes from the outer surface and contacts the periphery of the main body. The through hole is an emission port for emitting laser light to the outside of the frame.

[0006] An optical scanning device according to one aspect of the present invention includes a scanning optical system, a frame, and a pressing and holding component, which forms an electrostatic latent image that attenuates charge by exposing the surface of an image carrier. The scanning optical system scans a laser and guides the laser onto the image carrier. The frame accommodates the scanning optical system inside and has a holding portion, which holds the optical elements constituting the scanning optical system. The pressing and holding component presses the optical elements and holds the optical elements in the holding portion. The pressing and holding component has a main body and a pressing portion. The pressing portion is connected to the main body and presses the optical element held by the holding portion toward the holding portion. The frame has a supporting portion, which is formed opposite to the holding portion and supports the main body. The supporting portion is arranged on the periphery of a through hole that passes through the frame, and has a supporting protrusion. The supporting protrusion protrudes from the outer surface and contacts the periphery of the main body. The frame has: a storage portion, the upper surface of which is open, and the scanning optical system is arranged inside; and a cover portion, which covers the upper surface of the storage portion. The storage portion and the cover portion each have a wall portion that surrounds the scanning optical system from the side, and the through hole is formed in the wall portion of one of the storage portion and the cover portion and is blocked by the wall portion of the other of the storage portion and the cover portion.

[0007] According to an optical scanning device according to one aspect of the present invention, it is possible to provide an optical scanning device capable of stably holding an optical element while suppressing an increase in manufacturing cost, and an image forming apparatus including the optical scanning device.

[0008] Other objects of the present invention and specific advantages obtainable by the present invention will become more apparent from the description of the embodiments described below. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 It is a schematic cross-sectional view showing the overall structure of an image forming apparatus 100 equipped with the optical scanning device 5 of the present invention. Figure 2 It is a perspective view of the optical scanning device 5 according to one embodiment of the present invention. Figure 3 It is a perspective view of the optical scanning device 5 according to one embodiment of the present invention. Figure 4 yes Figure 2 AA section view in. Figure 5 It is a perspective view of a pressing spring 50 that presses and holds the reflecting mirror 49 b in the housing 48 of the optical scanning device 5 of the present invention. Figure 6 It is a partial cross-sectional view of the vicinity of the reflective mirror 49 b in the housing 48 of the optical scanning device 5 of the present invention. Figure 7 It is a perspective view of a pressing spring 80 that presses and holds the reflecting mirror 49 a in the housing 48 of the optical scanning device 5 of the present invention. Figure 8 yes Figure 2 BB section view in. Fig. 9 It is a partial cross-sectional view of the vicinity of the reflective mirror 49 a in the housing 48 of the optical scanning device 5 of the present invention. Fig.10 It is a partial cross-sectional view showing a modified example of the vicinity of the reflective mirror 49 b in the housing 48 of the optical scanning device 5 of the present invention. DETAILED DESCRIPTION

[0009] [1. Configuration of Image Forming Apparatus 100] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Figure 1 1 is a schematic cross-sectional view showing the overall structure of an image forming apparatus 100 equipped with the optical scanning device 5 of the present invention. Figure 1 In the state shown in the figure), the vertical direction is defined as the up-down direction (Z1-Z2 direction). Figure 1 The front-to-back direction (Y1-Y2 direction) is defined with the front surface (front surface) of the image forming apparatus 100 shown in the drawing as the front surface. In addition, the left-right direction (X1-X2 direction) is defined with the front surface of the image forming apparatus 100 in the set state as a reference. In the present embodiment, the left-right direction (X1-X2 direction) is orthogonal to the up-down direction (Z1-Z2 direction) and the front-to-back direction (Y1-Y2 direction).

[0010] The image forming apparatus 100 is a tandem color printer. The image forming apparatus 100 includes rotatable photosensitive drums 1a to 1d as image carriers. As the photosensitive drums 1a to 1d, an organic photosensitive body (OPC photosensitive body) having an organic photosensitive layer formed thereon or an amorphous silicon photosensitive body having an amorphous silicon photosensitive layer formed thereon is used. The photosensitive drums 1a to 1d are arranged in tandem corresponding to the respective colors of yellow, cyan, magenta, and black.

[0011] A developing device 3a, a charger 2a, and a cleaning device 7a are arranged around the photosensitive drum 1a. Similarly, developing devices 3b to 3d, chargers 2b to 2d, and cleaning devices 7b to 7d are arranged around the photosensitive drums 1b to 1d, respectively. In addition, an optical scanning device 5 is arranged above the developing devices 3a to 3d at Z1.

[0012] The developing devices 3a to 3d are respectively arranged at the right side X1 of the photosensitive drums 1a to 1d. The developing devices 3a to 3d are respectively opposed to the photosensitive drums 1a to 1d and supply toner to the photosensitive drums 1a to 1d. The developing devices 3a to 3d have containers 4a to 4d for storing toner of each color of magenta, cyan, yellow and black.

[0013] The chargers 2a to 2d are arranged upstream of the developing devices 3a to 3d in the rotation direction of the photosensitive drums 1a to 1d and face the surfaces of the photosensitive drums 1a to 1d. The chargers 2a to 2d uniformly charge the surfaces of the photosensitive drums 1a to 1d.

[0014] In this embodiment, the optical scanning device 5 is arranged above the photosensitive drums 1a to 1d at Z1. The optical scanning device 5 irradiates light (optical scanning) to the surfaces of the photosensitive drums 1a to 1d uniformly charged by the chargers 2a to 2d based on image data such as text and patterns input to the image input unit from a personal computer or the like. Thus, electrostatic latent images are formed on the surfaces of the photosensitive drums 1a to 1d.

[0015] The housing 48 of the optical scanning device 5 is a resin molded product, and includes a housing portion 481 with an opening on one surface (the upper surface in this embodiment) and a cover portion 482 covering the opening (see FIG. Figure 4 ). The storage unit 481 stores the scanning optical system 120 therein.

[0016] Lasers D1 to D4 are irradiated onto the surfaces of the photosensitive drums 1a to 1d from positions downstream of the chargers 2a to 2d in the rotation direction of the photosensitive drums 1a to 1d. As a result, electrostatic latent images are formed on the surfaces of the photosensitive drums 1a to 1d. These electrostatic latent images are developed into toner images by the developing devices 3a to 3d. The optical scanning device 5 will be described in detail later.

[0017] The endless intermediate transfer belt 8 is stretched between a driving roller 10 and a driven roller 11. The driving roller 10 is rotated by a motor (not shown), thereby Figure 1 The intermediate transfer belt 8 is driven to circulate in the clockwise direction.

[0018] The photosensitive drums 1a to 1d are arranged adjacent to each other along the conveying direction (X1-X2 direction) at Z1 above the intermediate transfer belt 8. The photosensitive drums 1a to 1d are in contact with the intermediate transfer belt 8, respectively.

[0019] The primary transfer rollers 6a to 6d are respectively opposed to the photosensitive drums 1a to 1d via the intermediate transfer belt 8. The primary transfer rollers 6a to 6d are respectively in pressure contact with the intermediate transfer belt 8 and together with the photosensitive drums 1a to 1d form primary transfer sections. In these primary transfer sections, the toner images are transferred onto the intermediate transfer belt 8.

[0020] Specifically, by applying a primary transfer voltage to the primary transfer rollers 6a to 6d, the toner images on the photosensitive drums 1a to 1d are sequentially transferred to the intermediate transfer belt 8 at a predetermined timing. Thus, a full-color toner image is formed on the surface of the intermediate transfer belt 8, in which four color toner images of magenta, cyan, yellow, and black are overlapped in a predetermined positional relationship.

[0021] The secondary transfer roller 9 is opposed to the driving roller 10 via the intermediate transfer belt 8. The secondary transfer roller 9 is in pressure contact with the intermediate transfer belt 8 and forms a secondary transfer section together with the driving roller 10. In the secondary transfer section, a secondary transfer voltage is applied to the secondary transfer roller 9, so that the toner image on the surface of the intermediate transfer belt 8 is transferred to the paper S. After the toner image is transferred, a belt cleaning device (not shown) cleans the toner remaining on the intermediate transfer belt 8.

[0022] A paper feed cassette 16 is disposed at the lower portion of the image forming apparatus 100 . The paper feed cassette 16 can accommodate a plurality of sheets of paper S. A paper conveyance path 19 is disposed to the right X1 of the paper feed cassette 16 .

[0023] The paper conveying path 19 conveys the paper S fed from the paper feeding cassette 16 to the secondary transfer unit. The fixing unit 13 and the paper conveying path 20 are arranged at the upper right of the image forming apparatus 100. The fixing unit 13 performs a fixing process on the image-formed paper S. The paper conveying path 20 conveys the fixed paper S to the paper discharge unit 17.

[0024] The sheets S stored in the paper feed cassette 16 are fed one by one to the paper conveyance path 19 by the pickup roller 12 a .

[0025] After the image forming operation on the intermediate transfer belt 8 and the paper feeding operation to the secondary transfer section are synchronized, the registration roller pair 12 b conveys the paper S to the secondary transfer section. The full-color toner image on the intermediate transfer belt 8 is secondarily transferred to the paper S conveyed to the secondary transfer section by the secondary transfer roller 9 to which the secondary transfer voltage is applied. The paper S to which the full-color toner image is transferred is conveyed to the fixing section 13.

[0026] The fixing section 13 includes a fixing belt heated by a heater, a fixing roller connected to the fixing belt, and a pressure roller in pressure contact with the fixing roller via the fixing belt. The fixing section 13 heats and pressurizes the paper S to which the toner image is transferred. Thus, a fixing process is performed. As needed, the paper S to which the toner image is fixed in the fixing section 13 is turned over in the paper conveying passage 18. After that, after the paper S is conveyed to the secondary transfer section again via the calibration roller pair 12b, a new toner image is secondarily transferred to the back of the paper S by the secondary transfer roller 9 and fixed in the fixing section 13. The paper S to which the toner image is fixed is discharged to the paper discharge section 17 through the paper conveying passage 20.

[0027] [2. Structure of optical scanning device] Figure 2 , Figure 3 is a perspective view of the optical scanning device 5, Figure 3 The state in which the cover part 482 is removed is shown. Figure 4 yes Figure 2AA section view in. Figure 4 The part of the schematic diagram shows the structure of each component, and does not strictly show the shape and positional relationship of each component. Figure 4 The first scanning lens 41 and the second scanning lens 42 are not shown.

[0028] In the following description, the main scanning direction (Y1-Y2 direction) is the longitudinal direction of the reflectors 49a to 49c. In addition, the main scanning direction (Y1-Y2 direction) is consistent with the extension direction of the rotation axis of the photosensitive drums 1a to 1d and the front-to-back direction of the image forming device 100. The sub-scanning direction (Z1-Z2 direction) is a direction parallel to the rotation axis J of the polygon mirror 45 and is consistent with the up-down direction of the image forming device 100. In addition, the left-right direction (X1-X2 direction) is a direction orthogonal to the main scanning direction (Y1-Y2 direction) and the sub-scanning direction (Z1-Z2 direction), and is consistent with the arrangement direction of the reflectors 49a to 49c.

[0029] The optical scanning device 5 outputs (irradiates) a plurality of (four in this embodiment) laser beams D1 to D4 modulated according to respective image signals to the photosensitive drums 1a to 1d, thereby exposing the surfaces of the photosensitive drums 1a to 1d to form electrostatic latent images for attenuating charging.

[0030] The optical scanning device 5 includes a light source unit 46 , a polygon mirror 45 , a pair of first scanning lenses 41 , a pair of second scanning lenses 42 , a pair of reflection mirrors 49 a , 49 b , and 49 c , and a housing 48 .

[0031] The frame 48 includes a storage portion 481 and a cover portion 482. The storage portion 481 is formed into a substantially quadrilateral shape in a plan view. The light source portion 46, the polygon mirror 45, a pair of first scanning lenses 41, a pair of second scanning lenses 42, and a pair of reflective mirrors 49a, 49b, 49c are stored inside the storage portion 481. The polygon mirror 45, the first scanning lens 41, the second scanning lens 42, and the reflective mirrors 49a to 49c constitute a scanning optical system 120, which scans the laser light D1 to D4 and guides it onto the photosensitive drums (image carriers) 1a to 1d.

[0032] The storage portion 481 includes a bottom wall portion 481a and a peripheral wall portion 481b. The bottom wall portion 481a extends in a direction perpendicular to the rotation axis J of the polygon mirror 45. The bottom wall portion 481a is formed with emission ports 483a to 483d (see FIG. 4 ) penetrating in the vertical direction. Figure 4). The ejection ports 483a to 483d extend along the main scanning direction (Y1-Y2 direction). The lasers D1 to D4 emitted from the scanning optical system 120 are emitted to the outside of the frame 48 through the ejection ports 483a to 483d, and are incident on the corresponding photosensitive drums 1a to 1d, respectively. The ejection ports 483a to 483d are covered by dustproof glasses 70a to 70d, respectively. Thus, dust can be prevented from intruding into the interior of the frame 48.

[0033] The peripheral wall portion 481b extends upward from the outer periphery of the bottom wall portion 481a, and surrounds the light source portion 46, the polygon mirror 45, the pair of first scanning lenses 41, the pair of second scanning lenses 42, and the pair of reflection mirrors 49a, 49b, 49c from the side.

[0034] The cover portion 482 includes a top portion 482a and a peripheral portion 482b. The top portion 482a covers the upper surface of the opening of the storage portion 481. The peripheral portion 482b extends downward from the outer periphery of the top portion 482a and covers a portion of the peripheral wall portion 481b from the radially outer side. That is, the storage portion 481 and the cover portion 482 respectively include wall portions 481b and 482b that surround the scanning optical system 120 from the side.

[0035] In addition, in this embodiment, the peripheral wall portion 481b has a through hole 484 that penetrates along the main scanning direction (Y1-Y2 direction) on one side (Y2 side) of the main scanning direction at both ends of the left-right direction (X1-X2). The through hole 484 is covered by the peripheral surface portion 482b (see Fig. 9 ). That is, the through hole 484 is formed in the peripheral wall portion 481b of one of the storage portion 481 and the cover portion 482, and is blocked by the peripheral surface portion 482b of the cover portion 482. Thus, dust can be prevented from intruding into the interior of the frame 48. In addition, the structure near the through hole 484 will be described in detail later.

[0036] The light source unit 46 includes a light emitting module (not shown), a collimator lens (not shown), and a cylindrical lens (not shown). Lasers D1 to D4 corresponding to the respective colors of Y (yellow), C (cyan), M (magenta), and K (black) are output from each light emitting module. The lasers D1 to D4 emitted from each light emitting module are irradiated toward the polygon mirror 45 through the collimator lens and the cylindrical lens.

[0037] At this time, the collimator lens (not shown) converts each laser D1 to D4 emitted from the light emitting module into substantially parallel light in the main scanning section. The cylindrical lens (not shown) converges the lasers D1 to D4 in the sub-scanning direction (Z1-Z2 direction) and focuses them near the deflection surface (reflection surface) of the polygon mirror 45. As a result, the lasers D1 to D4 form a linear image near the deflection surface of the polygon mirror 45.

[0038] The polygon mirror 45 is composed of a regular polygonal rotating polygon mirror having a plurality of deflection surfaces (reflection surfaces) on its side surface, and is rotated at a predetermined angular velocity around the rotation axis J by the polygon mirror motor 44 . The polygon mirror motor 44 is fixed to the bottom wall 481 a of the storage portion 481 .

[0039] The polygonal rotating mirror 45 is composed of a plurality of reflecting surfaces. In the present embodiment, the polygonal rotating mirror 45 is a polygonal mirror formed in the shape of a quadrangular prism. The laser light D1 and D2 incident on the polygonal rotating mirror 45 are deflected and scanned by any reflecting surface driven by rotation, reflected in the left direction (X2 direction) by the reflecting surface of the polygonal rotating mirror 45, and guided to the first scanning lens 41 and the second scanning lens 42, and reflected in the direction X2 to the left of the rotation axis J of the polygonal rotating mirror 45. On the other hand, the laser light D3 and D4 incident on the polygonal rotating mirror 45 are deflected and scanned by any reflecting surface driven by rotation, reflected in the right direction (X1 direction) by the reflecting surface of the polygonal rotating mirror 45, and guided to the first scanning lens 41 and the second scanning lens 42 (refer to Figure 4 ).

[0040] The second scanning lens 42 is arranged on the downstream side of the optical path of the laser beams D1 to D4 relative to the first scanning lens 41 .

[0041] The first scanning lens 41 is a lens having distortion aberration (fθ characteristic) and is a long lens extending in the main scanning direction (Y1 - Y2 direction). The first scanning lens 41 collects the laser beams D1 to D4 reflected by the deflection surface of the polygon mirror 45 .

[0042] The second scanning lens 42 is a lens having distortion aberration (fθ characteristic) similar to the first scanning lens 41, and is a long lens extending along the main scanning direction (Y1-Y2 direction). The second scanning lens 42 focuses the laser light D1-D4 after passing through the first scanning lens 41, and forms images of the laser light D1-D4 on the scanned surfaces of the photosensitive drums 1a-1d, respectively.

[0043] The pair of reflecting mirrors 49a reflects the laser beams D1 and D4, respectively. The pair of reflecting mirrors 49b and the pair of reflecting mirrors 49c reflect the laser beams D2 and D3, respectively.

[0044] Laser light D1 focused by the first scanning lens 41 and the second scanning lens 42 is reflected by the reflection mirror 49a and forms an image on the scanned surface of the photosensitive drum 1a. Laser light D4 focused by the first scanning lens 41 and the second scanning lens 42 is reflected by the reflection mirror 49a and forms an image on the scanned surface of the photosensitive drum 1d.

[0045] The laser light D2 focused by the first scanning lens 41 and the second scanning lens 42 is reflected by the reflection mirrors 49b and 49c to form an image on the scanned surface of the photosensitive drum 1b. The laser light D3 focused by the first scanning lens 41 and the second scanning lens 42 is reflected by the reflection mirrors 49b and 49c to form an image on the scanned surface of the photosensitive drum 1c.

[0046] The laser beams D1 to D4 reflected and deflected by the polygon mirror 45 are respectively focused on the scanned surfaces of the photosensitive drums 1a to 1d through the first scanning lens 41 and the second scanning lens 42. Thus, beam spots are formed on the scanned surfaces of the photosensitive drums 1a to 1d. In addition, the laser beams D1 to D4 focused on the scanned surfaces of the photosensitive drums 1a to 1d scan the scanned surfaces of the photosensitive drums 1a to 1d at a constant speed.

[0047] At this time, the lasers D1 to D4 scan the scanned surfaces (peripheral surfaces) of the photosensitive drums (image carriers) 1a to 1d in the main scanning direction (Y1-Y2 direction) by the rotation of the polygon mirror 45. In addition, the lasers D1 to D4 scan in the sub-scanning direction (Z1-Z2 direction) by the rotation of the photosensitive drums 1a to 1d, and form electrostatic latent images on the surfaces of the photosensitive drums 1a to 1d.

[0048] [3. Mounting structure of reflector 49b] Figure 5 4 is a perspective view of a pressing spring 50 (pressing and holding member) for pressing and holding the reflecting mirror 49b. Figure 6 It is a partial cross-sectional view showing the vicinity of the reflector 49 b in an enlarged manner, and shows a holding structure on one end side (Y2 side) in the longitudinal direction of the reflector 49 b.

[0049] The storage portion 481 includes a mirror holding portion (holding portion) 60 and a first spring support portion (support portion) 61 (see Figure 6 ). The mirror holding portion 60 and the first spring support portion 61 protrude upward (in the Z1 direction) from the upper surface of the bottom wall portion 481a. The mirror holding portion 60 is disposed at two locations at both ends of the bottom wall portion 481a in the main scanning direction (in the Y1-Y2 direction), and is disposed at a total of four locations (refer to Figure 3 ). That is, the housing 48 includes a mirror holding portion (holding portion) 60 , and the mirror holding portion 60 holds a reflecting mirror (optical element) 49 b constituting the scanning optical system 120 .

[0050] The upper surface of the mirror holding portion 60 is recessed downward to form a recessed portion 601. The recessed portion 601 has a first holding surface 601a and a second holding surface 601b. The first holding surface 601a faces the light reflecting surface of the reflector 49b in the left-right direction (X1-X2 direction). The second holding surface 601b faces the lower surface of the reflector 49b in the up-down direction (Z1-Z2 direction).

[0051] The first spring support parts 61 are disposed adjacent to one side (Y2 side) of the longitudinal direction of the ejection ports 483b and 483c, respectively, and are provided at two locations in total. Each first spring support part 61 has a support protrusion 61a. Each support protrusion 61a protrudes from the side surface of the first spring support part 61 in the left-right direction (X1-X2 direction) (refer to Figure 6 ).

[0052] That is, the frame body 48 has a first spring support portion (support portion) 61. The first spring support portion 61 is formed to face the mirror holding portion 60, and supports a spring main body portion (main body portion) 51 of a later-described pressing spring 50. The first spring support portion (support portion) 61 is arranged on the periphery of the through holes 483b and 483c penetrating the frame body 48, and has a supporting protrusion 61a.

[0053] The support protrusion 61a protrudes from the outer surface of the first spring support portion (support portion) 61. In addition, in the present embodiment, the support protrusion 61a extends in a direction close to the mirror holding portion 60. At this time, the through holes 483b and 483c arranged opposite to the support protrusion 61a are emission ports 483b and 483c for emitting the laser light D2 and D3 to the outside of the frame 48.

[0054] Furthermore, in the cross section perpendicular to the longitudinal direction (Y1-Y2 direction) of the reflector 49b, the tip of the support protrusion 61a is located inside the emission ports 483b and 483c.

[0055] The mirror holding portion 60 holds both ends of the reflecting mirror 49b in the longitudinal direction (both ends in the Y1-Y2 direction) (see Figure 3 ). The reflector 49b is fixed in the recess 601 via an adhesive 601c. In addition, one end (Y2 side) of the longitudinal direction of the reflector 49b is pressed by the pressing spring 50. The pressing spring 50 is supported by the first spring support portion 61, and the reflector 49b is stably held in the storage portion 481.

[0056] Specifically, the pressing spring (pressing and holding member) 50 is formed by bending a metal plate, and includes a spring main body (main body) 51 , a first pressing part (pressing part) 52 , and a second pressing part (pressing part) 53 .

[0057] A pair of claws 51a are formed at the upper end of the spring main body 51 with the second pressing portion 53 interposed therebetween. The claws 51a are bent in a direction away from the second pressing portion 53. The spring main body 51 is supported by the first spring support portion 61 (see Figure 6 ), the claw portion 51a is arranged on the upper surface of the first spring support portion 61. Thus, the pressing spring 50 is stably supported by the first spring support portion 61.

[0058] The first pressing portion 52 is connected to the lower end of the spring main body 51 via the first bent portion 50a. The first pressing portion 52 is inclined upward and extends as it moves away from the spring main body 51. In addition, the front end of the first pressing portion 52 is bent upward (Z1 direction) at the second bent portion 50b. The first pressing portion 52 is connected to the spring main body 51 so as to be elastically deformable with the first bent portion 50a as a bending fulcrum. A hemispherical first pressing contact point 52a is formed at the front end of the first pressing portion 52 (closer to the front end side than the second bent portion 50b).

[0059] The second pressing portion 53 is connected to the upper end of the spring main body 51 via the third bent portion 50c. The second pressing portion 53 extends from the spring main body 51 in the same direction as the first pressing portion 52. The front end of the second pressing portion 53 is bent at the fourth bent portion 50d to be in an inverted V shape in side view. The second pressing portion 53 is connected to the spring main body 51 so as to be elastically deformable with the third bent portion 50c as a bending fulcrum. A hemispherical second pressing contact point 53a is formed at the front end of the second pressing portion 53 (closer to the front end side than the third bent portion 50d).

[0060] The pressing spring 50 is formed with a slit 50 e extending across the upper end of the spring body 51 and the base of the second pressing portion 53 .

[0061] The pressing spring 50 is inserted between the light reflecting surface of the reflector 49b and the first spring support portion 61. At this time, the lower end of the slit 50e contacts the supporting protrusion 61a. That is, the supporting protrusion 61a contacts the periphery of the spring main body (main body) 51. Thus, the pressing spring 50 is easily positioned on the first spring support portion 61. The first pressing portion 52 contacts the light reflecting surface of the reflector 49b at the first pressing contact point 52a. The second pressing portion 53 contacts the upper surface of the reflector 49b at the second pressing contact point 53a.

[0062] Thus, the reflecting mirror 49b is pressed against the first holding surface 601a by the acting force of the first pressing portion 52 of the pressing spring 50. In addition, the reflecting mirror 49b is pressed against the second holding surface 601b by the acting force of the second pressing portion 53 of the pressing spring 50. That is, the first pressing portion (pressing portion) 52 and the second pressing portion (pressing portion) 53 press the reflecting mirror (optical element) 49b held by the mirror holding portion (holding portion) 60 toward the mirror holding portion (holding portion) 60.

[0063] According to this configuration, the reflecting mirror 49b can be held on the first holding surface 601a and the second holding surface 601b of the mirror holding portion 60 using one pressing spring 50. Therefore, the reflecting mirror 49b can be stably held without increasing the number of pressing springs 50.

[0064] In addition, when resin molding is performed by clamping the storage portion 481 from the top and bottom directions (Z1-Z2 direction) by the mold, the ejection ports 483b and 483c can be used as demolding holes of the mold. As a result, the supporting protrusion 61a can be easily molded. By utilizing the ejection ports 483b and 483c formed on the optical path of the lasers D2 and D3, it is not necessary to newly form a through hole in the frame 48 for forming the supporting protrusion 61a. In addition, the ejection ports 483b and 483c are covered by dustproof glasses 70b and 70c, and it is not necessary to newly set up a component covering the through hole. Therefore, it is possible to provide an optical scanning device 5 that can suppress an increase in manufacturing costs and stably hold the reflector (optical element) 49b, and an image forming device 100 having the optical scanning device 5.

[0065] In the cross section perpendicular to the longitudinal direction (Y1-Y2 direction) of the reflector 49b, the tip of the support protrusion 61a is located inside the ejection holes 483b and 483c. Thus, the ejection holes 483b and 483c can be used as mold release holes to more easily mold the support protrusion 61a.

[0066] In addition, the front end of the support protrusion 61a can also be bent in a direction close to the through holes 483b and 483c. As a result, the front end of the support protrusion 61a can be clamped to the lower end of the slit 50e. That is, the support protrusion 61a is clamped to the periphery of the spring main body (main body) 51. Therefore, the pressing spring 50 can be stably supported on the first spring support part (support part) 61. In addition, even when the front end of the support protrusion 61a is bent, the ejection holes 483b and 483c can be used as demolding holes of the mold to more easily form the support protrusion 61a.

[0067] [4. Mounting structure of reflector 49a] Figure 7 FIG. 4 is a perspective view of a pressing spring 80 (pressing and holding member) for pressing and holding the reflecting mirror 49a. Figure 8 yes Figure 2 BB section view in. Fig. 9 It is a partial cross-sectional view showing the vicinity of the reflector 49 a in an enlarged manner, and shows a holding structure on one end side (Y2 side) in the longitudinal direction of the reflector 49 a.

[0068] The storage portion 481 includes a mirror holding portion 62 and a second spring support portion 63 (see Figure 8 ). The mirror holding portion 62 and the second spring support portion 63 protrude upward (in the Z1 direction) from the upper surface of the bottom wall portion 481a. The mirror holding portion 62 is disposed at two locations at both ends of the bottom wall portion 481a in the main scanning direction (in the Y1-Y2 direction), and is disposed at a total of four locations.

[0069] The mirror holding portion 62 has a protruding holding portion 62a protruding from the side toward the length direction (Y1-Y2 direction) of the reflector 49a. The protruding holding portion 62a has a protruding portion 62b protruding from the upper surface of the front end. The upper end of the mirror holding portion 62 is opposite to the side of the reflector 49a in the length direction (Y1-Y2 direction). The protruding portion 62b is opposite to the lower surface of the reflector 49a in the up-down direction (Z1-Z2 direction).

[0070] The second spring support portion 63 is formed as a part of the peripheral wall portion 481b on the Y2 side of the storage portion 481, and a pair of the second spring support portions 63 are arranged at each of the two ends in the left-right direction (X1-X2 direction). A through hole 484 is formed on the left side X2 of the second spring support portion 63 arranged at the end on the left side X2. In addition, a through hole 484 is formed on the right side X1 of the second spring support portion 63 arranged at the end on the right side X1. Each of the second spring support portions 63 has a support protrusion 63a. Each of the support protrusions 63a protrudes from the side surface of the second spring support portion 63 in the forward direction (Y1 direction) (refer to Fig. 9 ).

[0071] That is, the frame body 48 has a second spring support portion (support portion) 63. The second spring support portion 63 is formed to face the mirror holding portion 62, and supports a spring main body portion (main body portion) 81 of a later-described pressing spring 80. The second spring support portion (support portion) 63 is arranged at the periphery of a through hole 484 penetrating the frame body 48, and has a supporting protrusion 63a.

[0072] The support protrusion 63a protrudes from the outer surface of the second spring support portion (support portion) 63. In the present embodiment, the support protrusion 63a extends in a direction approaching the mirror holding portion 62. At this time, the support protrusion 63a is arranged to face the through hole 484.

[0073] In addition, in a cross section in the left-right direction (X1-X2 direction) orthogonal to the axial direction of the rotation axis J of the polygonal mirror 45 included in the scanning optical system and the length direction (Y1-Y2 direction) of the reflection mirror 49a, the front end of the supporting protrusion 63a is located on the inner side of the through hole 484.

[0074] The mirror holding portion 62 holds both ends of the reflecting mirror 49a in the longitudinal direction (both ends in the Y1-Y2 direction) (see Figure 8 ). Specifically, the reflector 49a is clamped in the longitudinal direction (Y1-Y2 direction) by a pair of mirror holding portions 62, and the lower surface of the reflector 49a is supported by the protrusion 62b. In addition, one end portion (Y2 side) in the longitudinal direction of the reflector 49a is pressed by the pressing spring 80. The pressing spring 80 is supported by the second spring support portion 63, and the reflector 49a is stably held in the storage portion 481.

[0075] Specifically, the pressing spring (pressing and holding member) 80 is formed by bending a metal plate, and includes a spring main body portion (main body portion) 81 , a pair of third pressing portions (pressing portions) 83 , and a pair of curved support portions 84 .

[0076] The spring main body 81 is supported by the second spring support portion 63 of the frame 48. A pair of curved support portions 84 are connected to the lower end of the spring main body 81 via the sixth curved portion 80f and extend downward. The curved support portion 84 is substantially parallel to the spring main body 81. The sixth curved portion 80f is curved to the same side as the direction in which the third pressing portion 83 extends. The curved support portion 84 is arranged on the step portion 63b, which protrudes from the lower end of the second spring support portion 63 to the other side (Y1 side) in the longitudinal direction.

[0077] A pair of third pressing portions 83 are connected to the upper end of the spring main body 81 via the fifth bent portion 80e. The pair of third pressing portions 83 are inclined downward and extend as they are away from the spring main body 81. The third pressing portion 83 is elastically deformably connected to the spring main body 81 with the fifth bent portion 80e as a bending fulcrum. A hemispherical third pressing contact point 83a is formed at the front end of the third pressing portion 83.

[0078] The pressing spring 80 is formed with a slit 85 extending across the upper end portion of the spring body 81 and the third pressing portion 83 .

[0079] In the longitudinal direction (Y1-Y2 direction), the pressing spring 80 is inserted between the reflecting mirror 49a and the second spring supporting portion 63. The pressing spring 80 has a supporting protrusion 63a abutting between a pair of third pressing portions 83 at the upper end of the spring main body 81. Thus, the pressing spring 80 is easily positioned on the second spring supporting portion 63. The pair of third pressing portions 83 are in contact with the two upper surfaces at one end side (Y2 side) in the longitudinal direction of the reflecting mirror 49a at the third pressing contact point 83a.

[0080] Thus, the reflecting mirror 49a is pressed against the protrusion 62b by the urging force of the third pressing portion 83 of the pressing spring 80. That is, the third pressing portion (pressing portion) 83 presses the reflecting mirror (optical element) 49a held by the mirror holding portion (holding portion) 62 toward the mirror holding portion (holding portion) 62.

[0081] According to this configuration, the reflecting mirror 49a can be held by the mirror holding portion 62 using one pressing spring 80. Therefore, the reflecting mirror 49a can be stably held without increasing the number of pressing springs 80.

[0082] In addition, when the resin molding is performed by sandwiching the storage portion 481 from the front-to-back direction (Y1-Y2 direction) by the mold, the through hole 484 can be used as a demolding hole of the mold. Thus, the supporting protrusion 63a can be easily formed. In addition, the through hole 484 is covered by the peripheral surface portion 482b. Thus, by using the cover portion 482, it is not necessary to newly set a component covering the through hole 484. Therefore, it is possible to provide an optical scanning device 5 that can suppress the increase in manufacturing cost and stably hold the reflector (optical element) 49a and an image forming device 100 having the optical scanning device 5.

[0083] In the cross section in the left-right direction (X1-X2 direction), the front end of the support protrusion 63a is located inside the through hole 484. Thus, the support protrusion 63a can be formed more easily by using the through hole 484 as a mold release hole.

[0084] In addition, the front end of the support protrusion 63a may be bent in a direction close to the through hole 484. Thus, the front end of the support protrusion 63a can be locked to the upper end of the spring main body 81. That is, the support protrusion 63a is locked to the periphery of the spring main body (main body) 81. Therefore, the pressing spring 80 is stably supported by the second spring support portion (support portion) 63. In addition, even when the front end of the support protrusion 63a is bent, the through hole 484 can be used as a demolding hole of the mold to more easily form the support protrusion 63a.

[0085] In addition, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the gist of the present invention. Fig.10 4 is a partial cross-sectional view showing a modified example of the mounting structure of the reflector 49b, and a spring clamping portion (clamping portion) 64 may be provided. In this case, the storage portion 481 further includes a spring clamping portion 64. The spring clamping portion 64 protrudes upward (in the Z1 direction) from the upper surface of the bottom wall portion 481a.

[0086] The spring clamping portion 64 and the first spring supporting portion 61 are arranged opposite to each other in the left-right direction (X1-X2 direction). The spring main body 51 is clamped between the spring clamping portion 64 and the first spring supporting portion 61. In the present embodiment, a pair of spring clamping portions 64 are arranged across the first pressing portion 52. That is, the frame 48 also has a spring clamping portion (clamping portion) 64 formed opposite to the first spring supporting portion (supporting portion) 61, and the spring main body (main body) 51 is clamped between the first spring supporting portion (supporting portion) 61 and the spring clamping portion (clamping portion) 64. As a result, the pressing spring 50 is more stably supported by the first spring supporting portion 61, and the pressing spring 50 can be prevented from rotating and falling off.

[0087] In addition, in the above-mentioned embodiments, the structure in which the pressing springs 50 and 80 press and hold the reflectors 49a and 49b is described, but the optical elements pressed and held by the pressing springs 50 and 80 are not limited to the reflectors 49a and 49b, but may also be the first scanning lens 41, the second scanning lens 42 or the reflector 49c.

[0088] In addition, as an image forming device 100 equipped with an optical scanning device 5, a serial color printer is used as an example for explanation, but the present invention is not limited to color printers, but can also be applied to color image forming devices using electronic photography such as color copiers and fax machines, or black and white image forming devices using electronic photography such as black and white printers and black and white multifunction peripherals.

[0089] The present invention can be used in an optical scanning device that forms a latent image on a scanned surface by exposure scanning.

Claims

1. An optical scanning device, characterized in that: include: A scanning optical system for scanning laser light and directing the laser light onto an image carrier; a frame body that accommodates the scanning optical system inside and has a holding portion that holds optical elements constituting the scanning optical system; as well as A pressing holding member presses the optical element to hold the optical element in the holding portion, The optical scanning device forms an electrostatic latent image that decays the charge by exposing the surface of the image carrier. The pressing and holding component comprises: Main body; as well as A pressing portion is connected to the main body portion and presses the optical element held by the holding portion toward the holding portion. The frame body includes a support portion, the support portion is formed to face the holding portion and supports the main body portion. The support portion is arranged at the periphery of the through hole penetrating the frame body. The support portion has a support protrusion, which protrudes from the outer surface and contacts the peripheral edge of the main body. The through hole is an emission port for emitting the laser light to the outside of the frame.

2. The optical scanning device according to claim 1, characterized in that: The optical element is a mirror that reflects the laser light. In a cross section perpendicular to the longitudinal direction of the reflector, the front end of the supporting protrusion is located inside the through hole.

3. The optical scanning device according to claim 1 or 2, characterized in that: The supporting protrusion extends in a direction approaching the holding portion, The front end portion of the supporting protrusion is bent in a direction approaching the through hole.

4. The optical scanning device according to claim 1 or 2, characterized in that: The frame further includes a clamping portion formed opposite to the supporting portion. The main body portion is clamped between the support portion and the clamping portion.

5. An optical scanning device, characterized in that: include: A scanning optical system for scanning laser light and directing the laser light onto an image carrier; a frame body that accommodates the scanning optical system inside and has a holding portion that holds optical elements constituting the scanning optical system; as well as A pressing holding member presses the optical element to hold the optical element in the holding portion, The optical scanning device forms an electrostatic latent image that decays the charge by exposing the surface of the image carrier. The pressing and holding component comprises: Main body; as well as A pressing portion is connected to the main body portion and presses the optical element held by the holding portion toward the holding portion. The frame body includes a support portion, the support portion is formed to face the holding portion and supports the main body portion. The support portion is arranged at the periphery of the through hole penetrating the frame body. The support portion has a support protrusion, which protrudes from the outer surface and contacts the peripheral edge of the main body. The frame has: A storage portion, the upper surface of which is open, and the scanning optical system is arranged inside; as well as a cover portion, covering an upper surface of the storage portion, The storage portion and the cover portion each have a wall portion surrounding the scanning optical system from the side. The through hole is formed in the wall portion of one of the housing portion and the cover portion and is closed by the wall portion of the other of the housing portion and the cover portion.

6. The optical scanning device according to claim 5, characterized in that: The optical element is a mirror that reflects the laser light. In a cross section in a direction perpendicular to an axial direction of a rotation axis of a polygon mirror included in the scanning optical system and a longitudinal direction of the reflecting mirror, a tip end of the supporting protrusion is located inside the through hole.

7. The optical scanning device according to claim 5 or 6, characterized in that: The supporting protrusion extends in a direction approaching the holding portion, The front end portion of the supporting protrusion is bent in a direction approaching the through hole.

8. An image forming device, characterized in that: include: One or more image carriers having a photosensitive layer formed on the surface; A charging device for charging the image carrier to a predetermined surface potential; as well as The optical scanning device according to claim 1 or 5 forms an electrostatic latent image that attenuates the charging by exposing the surface of the image carrier that has been charged by the charging device.

Images