Optical scanning device and image forming apparatus comprising the same

Abstract

To provide: an optical scanning device which comprises an optical element, is suppressed in increase in the manufacturing cost of the optical scanning device and furthermore can stably hold the optical element; and an image forming apparatus comprising the optical scanning device.SOLUTION: An optical scanning device comprises a scanning optical system, a casing, and a pressurizing-holding member. The casing houses in the inside thereof, the scanning optical system, and includes a holding portion holding an optical element configuring the scanning optical system. The pressurizing-holding member pressurizes the optical element and holds it in the holding portion. The pressurizing-holding member includes a main body portion and a pressurizing portion. The pressurizing portion is coupled to the main body portion, and pressurizes the optical element held by the holding portion, to the holding portion. The casing includes a support portion provided to face the holding portion and supporting the main body portion. The support portion is disposed in a peripheral edge of a through-hole penetrating through the casing, and includes a support protrusion portion. The support protrusion portion protrudes from an outer surface and comes in contact with a peripheral edge of the main body portion. The through-hole is an emission port emitting a laser beam toward the outside of the casing.SELECTED DRAWING: Figure 6

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 to an image forming apparatus equipped with the same, such as a copying machine, a printer, a facsimile, or a combination machine thereof. [Background technology]

[0002] A conventional optical scanning device is disclosed in Patent Document 1. This optical scanning device includes a scanning optical system that scans a laser beam and guides it onto an image carrier, a housing, and a pressing and holding member, and exposes the surface of the image carrier to form an electrostatic latent image in which the charge is attenuated. The housing accommodates the scanning optical system therein and has a holding section that holds the optical elements that constitute the scanning optical system. The pressing and holding member presses the optical elements to hold them in the holding section. The housing has a support section that is formed opposite the holding section and supports the pressing and holding member. The pressing and holding member is inserted into a through hole that penetrates the housing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-020130 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional optical scanning device described above, dust may enter the housing through the through hole, which may require the provision of a new member to block the through hole, thereby increasing the manufacturing cost of the optical scanning device.

[0005] In view of the above problems, 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 costs, and an image forming apparatus including the same. [Means for solving the problem]

[0006] In order to achieve the above object, a first configuration of the present invention is an optical scanning device that includes a scanning optical system, a housing, and a pressing and holding member, and that exposes the surface of an image carrier to form an electrostatic latent image in which the charge is attenuated. The scanning optical system scans a laser beam and guides it onto the image carrier. 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 to hold it in the holding section. The pressing and holding member has a main body section and a pressing section. The pressing section is connected to the main body section and presses the optical element held in the holding section toward the holding section. The housing has a support section that is formed opposite to the holding section and supports the main body section. The support section is disposed on the periphery of a through hole that penetrates the housing, and has a support protrusion. The support protrusion protrudes from the outer surface and contacts the periphery of the main body section. The through hole is an emission port that emits the laser beam to the outside of the housing.

[0007] In order to achieve the above object, the second configuration of the present invention is an optical scanning device that includes a scanning optical system, a housing, and a pressing and holding member, and that exposes the surface of an image carrier to form an electrostatic latent image in which the charge is attenuated. The scanning optical system scans a laser beam and guides it onto the image carrier. The housing houses 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 to hold it in the holding section. The pressing and holding member has a main body section and a pressing section. The pressing section is connected to the main body section and presses the optical element held in the holding section toward the holding section. The housing has a support section that is formed opposite to the holding section and supports the main body section. The support section is disposed on the periphery of a through hole that penetrates the housing, and has a support protrusion. The support protrusion protrudes from the outer surface and contacts the periphery of the main body section. The housing has a storage section that has an open top surface and in which the scanning optical system is disposed, and a lid section that covers the top surface of the storage section. The container and the lid each have a wall that laterally surrounds the scanning optical system, and the through hole is formed in one of the walls of the container or the lid and is blocked by the other wall of the container or the lid. Effect of the Invention

[0008] According to the first 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 costs, and an image forming apparatus including the same. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view showing the overall configuration of an image forming apparatus 100 equipped with an optical scanning device 5 according to the present invention. [Diagram 2] FIG. 1 is a perspective view of an optical scanning device 5 according to an embodiment of the present invention. [Diagram 3] FIG. 1 is a perspective view of an optical scanning device 5 according to an embodiment of the present invention. [Figure 4] Cross section taken along the line AA in Figure 2 [Diagram 5] 4 is a perspective view of a pressure spring 50 that presses and holds a reflection mirror 49b in a housing 48 of the optical scanning device 5 of the present invention. [Figure 6] FIG. 1 is a partial cross-sectional view of the vicinity of a reflecting mirror 49b in a housing 48 of the optical scanning device 5 of the present invention. [Figure 7] 1 is a perspective view of a pressure spring 50 that presses and holds a reflecting mirror 49a in a housing 48 of an optical scanning device 5 according to the present invention; [Figure 8] Cross section B-B in Fig. 2 [Figure 9] FIG. 1 is a partial cross-sectional view of the vicinity of a reflecting mirror 49a in a housing 48 of an optical scanning device 5 according to the present invention. [Figure 10] FIG. 11 is a partial cross-sectional view showing a modification of the vicinity of the reflecting mirror 49b in the housing 48 of the optical scanning device 5 of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [1. Configuration of image forming apparatus 100] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing the overall configuration of an image forming apparatus 100 in which an optical scanning device 5 of the present invention is mounted. For convenience of explanation, the vertical direction in an installation state (as shown in FIG. 1) in which the image forming apparatus 100 can be used is defined as the up-down direction (Z1-Z2 direction). In addition, the front side of the paper of the image forming apparatus 100 shown in FIG. 1 is defined as the front (front face) and the front-rear direction (Y1-Y2 direction) is defined. In addition, the left-right direction (X1-X2 direction) is defined with the front face of the image forming apparatus 100 in the installation state as a reference. In this embodiment, the left-right direction (X1-X2 direction) is perpendicular to the up-down direction (Z1-Z2 direction) and the front-rear direction (Y1-Y2 direction).

[0011] The image forming apparatus 100 is a tandem type color printer. The image forming apparatus 100 includes rotatable photoconductor drums 1a to 1d as image carriers. For the photoconductor drums 1a to 1d, an organic photoconductor (OPC photoconductor) having an organic photosensitive layer formed thereon, or an amorphous silicon photoconductor having an amorphous silicon photosensitive layer formed thereon, or the like, is used. The photoconductor drums 1a to 1d are arranged in tandem corresponding to the respective colors of yellow, cyan, magenta, and black.

[0012] Around the photoconductor drum 1a, a developing device 3a, a charger 2a, and a cleaning device 7a are disposed. Similarly, around the photoconductor drums 1b to 1d, developing devices 3b to 3d, chargers 2b to 2d, and cleaning devices 7b to 7d are disposed, respectively. In addition, an optical scanning device 5 is disposed above Z1 the developing devices 3a to 3d.

[0013] The developing devices 3a to 3d are disposed on the left side X2 of the photoconductor drums 1a to 1d, respectively. The developing devices 3a to 3d face the photoconductor drums 1a to 1d, respectively, and supply toner to the photoconductor drums 1a to 1d. The developing devices 3a to 3d have containers 4a to 4d, which contain magenta, cyan, yellow, and black toner, respectively.

[0014] The chargers 2a to 2d are disposed upstream of the developing devices 3a to 3d in the rotation direction of the photoconductor drums 1a to 1d and face the surfaces of the photoconductor drums 1a to 1d, respectively. The chargers 2a to 2d uniformly charge the surfaces of the photoconductor drums 1a to 1d, respectively.

[0015] In this embodiment, the optical scanning device 5 is disposed above the photoconductor drums 1a-1d at Z1. The optical scanning device 5 irradiates light (optical scanning) onto the surfaces of the photoconductor drums 1a-1d uniformly charged by the chargers 2a-2d based on image data such as characters and patterns input to an image input unit from a personal computer or the like. As a result, electrostatic latent images are formed on the surfaces of the photoconductor drums 1a-1d.

[0016] The housing 48 of the optical scanning device 5 is a resin molded product, and includes a storage section 481 having one opening on one surface (the upper surface in this embodiment) and a lid section 482 that covers the opening (see FIG. 4). The storage section 481 stores the scanning optical system 120 therein.

[0017] The laser beams D1-D4 are irradiated onto the surfaces of the photoconductor drums 1a-1d from downstream of the chargers 2a-2d in the direction of rotation of the photoconductor drums 1a-1d, respectively. As a result, electrostatic latent images are formed on the surfaces of the photoconductor drums 1a-1d. These electrostatic latent images are developed into toner images by the developing devices 3a-3d. The optical scanning device 5 will be described in detail later.

[0018] An endless intermediate transfer belt 8 is stretched around a drive roller 10 and a driven roller 11. When the drive roller 10 is rotated by a motor (not shown), the intermediate transfer belt 8 is driven to circulate in the clockwise direction in FIG.

[0019] The photoconductor drums 1a to 1d are arranged adjacent to each other along the transport direction (the direction of the arrow in FIG. 1) above the intermediate transfer belt 8. The photoconductor drums 1a to 1d are in contact with the intermediate transfer belt 8, respectively.

[0020] The primary transfer rollers 6a to 6d face the photoconductor drums 1a to 1d, respectively, with the intermediate transfer belt 8 therebetween. The primary transfer rollers 6a to 6d are pressed against the intermediate transfer belt 8, respectively, and form primary transfer portions together with the photoconductor drums 1a to 1d. In these primary transfer portions, toner images are transferred to the intermediate transfer belt 8.

[0021] Specifically, a primary transfer voltage is applied to the primary transfer rollers 6a to 6d, so that the toner images on the photoconductor drums 1a to 1d are transferred sequentially at a predetermined timing onto the intermediate transfer belt 8. As a result, a full-color toner image is formed on the surface of the intermediate transfer belt 8, in which toner images of four colors, magenta, cyan, yellow, and black, are superimposed in a predetermined positional relationship.

[0022] The secondary transfer roller 9 faces the drive roller 10 with the intermediate transfer belt 8 sandwiched therebetween. The secondary transfer roller 9 is pressed against the intermediate transfer belt 8 and forms a secondary transfer section together with the drive roller 10. In this 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 off any toner remaining on the intermediate transfer belt 8.

[0023] A paper feed cassette 16 is disposed at the bottom inside the image forming apparatus 100. The paper feed cassette 16 is capable of storing a plurality of sheets of paper S. To the right X1 of the paper feed cassette 16, a paper transport path 19 is disposed.

[0024] The paper transport path 19 transports the paper S fed from the paper feed cassette 16 to the secondary transfer unit. A fixing unit 13 and a paper transport path 20 are disposed in the upper right corner of the image forming apparatus 100. The fixing unit 13 performs a fixing process on the paper S on which an image has been formed. The paper transport path 20 transports the paper S which has been subjected to the fixing process to the paper discharge unit 17.

[0025] The sheets S stored in the paper feed cassette 16 are fed one by one to the paper transport path 19 side by the pickup roller 12a.

[0026] The pair of registration rollers 12b transports the paper S to the secondary transfer section in accordance with the timing of the image forming operation on the intermediate transfer belt 8 and the paper feeding operation to the secondary transfer section. The full-color toner image on the intermediate transfer belt 8 is secondarily transferred onto the paper S transported to the secondary transfer section by a secondary transfer roller 9 to which a secondary transfer voltage is applied. The paper S to which the full-color toner image has been transferred is transported to a fixing section 13.

[0027] The fixing unit 13 includes a fixing belt heated by a heater, a fixing roller in contact with the fixing belt, and a pressure roller pressed against the fixing roller with the fixing belt sandwiched therebetween. The fixing unit 13 heats and presses the paper S onto which the toner image has been transferred. This performs the fixing process. The paper S onto which the toner image has been fixed in the fixing unit 13 is turned over in the paper transport path 18 as necessary. The paper S is then transported again to the secondary transfer unit via the pair of registration rollers 12b, after which a new toner image is secondarily transferred onto the rear surface of the paper S by the secondary transfer roller 9, and fixed in the fixing unit 13. The paper S onto which the toner image has been fixed passes through the paper transport path 20 and is discharged to the paper discharge unit 17.

[0028] [2. Configuration of optical scanning device] 2 and 3 are perspective views of the optical scanning device 5, and FIG. 3 shows a state in which the cover 482 is removed. FIG. 4 is a cross-sectional view taken along line AA in FIG. 2. A part of FIG. 4 shows the configuration of each member in a schematic manner, and does not strictly show the shape and positional relationship of each member. Also, FIG. 4 does not show the first scanning lens 41 and the second scanning lens 42.

[0029] In the following description, the main scanning direction (Y1-Y2 direction) is the longitudinal direction of the reflecting mirrors 49a to 49c. The main scanning direction (Y1-Y2 direction) coincides with the direction in which the rotation axes of the photosensitive drums 1a to 1d extend and with the front-rear direction of the image forming apparatus 100. The sub-scanning direction (Z1-Z2 direction) is parallel to the rotation axis J of the polygon mirror 45 and coincides with the up-down direction of the image forming apparatus 100. The left-right direction (X1-X2 direction) is perpendicular to the main scanning direction (Y1-Y2 direction) and the sub-scanning direction (Z1-Z2 direction), and coincides with the juxtaposition direction of the reflecting mirrors 49a to 49c.

[0030] The optical scanning device 5 outputs (irradiates) multiple (four in this embodiment) laser beams D1 to D4 modulated according to each image signal onto the photosensitive drums 1a to 1d, exposing the surfaces of the photosensitive drums 1a to 1d to form electrostatic latent images with attenuated charge.

[0031] 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 reflecting mirrors 49a, 49b, and 49c, and a housing .

[0032] The housing 48 includes a storage section 481 and a cover section 482. The storage section 481 is formed in a substantially rectangular shape when viewed from above. The storage section 481 stores therein a light source section 46, a polygon mirror 45, a pair of first scanning lenses 41, a pair of second scanning lenses 42, and a pair of reflecting mirrors 49a, 49b, and 49c. The polygon mirror 45, the first scanning lens 41, the second scanning lens 42, and the reflecting mirrors 49a to 49c constitute a scanning optical system 120 that scans the laser beams D1 to D4 and guides them onto the photosensitive drums (image carriers) 1a to 1d.

[0033] The storage section 481 has a bottom wall section 481a and a peripheral wall section 481b. The bottom wall section 481a expands in a direction perpendicular to the rotation axis J of the polygon mirror 45. The bottom wall section 481a has exit ports 483a to 4813 penetrating in the up-down direction (see FIG. 4). The exit ports 483a to 483d extend in the main scanning direction (Y1-Y2 direction). The laser beams D1 to D4 emitted from the scanning optical system 120 are emitted to the outside of the housing 48 through the exit ports 483a to 483d and enter the corresponding photoconductor drums 1a to 1d, respectively. The exit ports 483a to 483d are covered with dustproof glasses 70a to 70d, respectively. This makes it possible to prevent dust from entering the housing 48.

[0034] The peripheral wall portion 481b extends upward from the outer periphery of the bottom wall portion 481a and laterally surrounds the light source unit 46, the polygon mirror 45, the pair of first scanning lenses 41, the pair of second scanning lenses 42, and the pair of reflecting mirrors 49a, 49b, 49c inside.

[0035] The lid portion 482 has a top surface portion 482a and a peripheral surface portion 482b. The top surface portion 482a covers the open upper surface of the storage portion 481. The peripheral surface portion 482b extends downward from the outer periphery of the top surface portion 482a and covers a part of the peripheral wall portion 481b from the radially outer side. That is, the storage portion 481 and the lid portion 482 each have wall portions 481b, 482b that laterally surround the scanning optical system 120.

[0036] In this embodiment, the peripheral wall portion 481b has a through hole 484 penetrating in the main scanning direction (Y1-Y2 direction) on one side (Y1 side) in the main scanning direction of both ends in 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 one wall portion 481b of the storage portion 481 or the lid portion 482, and is blocked by the other wall portion 482b of the storage portion 481 or the lid portion 482. This can prevent dust from entering the inside of the housing 48. The configuration in the vicinity of the through hole 484 will be described in detail later.

[0037] The light source unit 46 has a light emitting module (not shown), a collimator lens (not shown), and a cylindrical lens (not shown). Each of the light emitting modules outputs laser light D1 to D4 corresponding to each color of Y (yellow), C (cyan), M (magenta), and K (black). The laser light D1 to D4 emitted from each of the light emitting modules passes through the collimator lens and the cylindrical lens and is irradiated onto the polygon mirror 45.

[0038] At this time, a collimator lens (not shown) converts each of the laser beams D1 to D4 emitted from the light emitting modules into approximately parallel beams in the main scanning cross section. A cylindrical lens (not shown) converges the laser beams 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 laser beams D1 to D4 form a line image near the deflection surface of the polygon mirror 45.

[0039] The polygon mirror 45 is a regular polygonal rotating polygon mirror having a plurality of deflecting surfaces (reflecting surfaces) on its side surfaces, and is rotated around a rotation axis J at a predetermined speed by a polygon motor 44. The polygon motor 44 is fixed to a bottom wall portion 481a of the storage portion 481.

[0040] The polygon mirror 45 is composed of a plurality of reflecting surfaces. In this embodiment, the polygon mirror 45 is a polygonal mirror formed in a quadrangular prism shape. The laser beams D1 and D2 incident on the polygon mirror 45 are deflected and scanned by any of the reflecting surfaces that rotate, reflected in the left direction (X2 direction) by the reflecting surface of the polygon mirror 45, and guided to the first scanning lens 41 and the second scanning lens 42. They are reflected in the left direction X2 from the rotation axis J of the polygon mirror 45. On the other hand, the laser beams D2 and D3 incident on the polygon mirror 45 are deflected and scanned by any of the reflecting surfaces that rotate, reflected in the right direction (X2 direction) by the reflecting surface of the polygon mirror 45, and guided to the first scanning lens 41 and the second scanning lens 42 (see FIG. 3).

[0041] The second scanning lens 42 is disposed downstream of the first scanning lens 41 in the optical paths of the laser beams D1 to D4.

[0042] The first scanning lens 41 is a lens having distortion (fθ characteristics) and is a long lens extending along 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.

[0043] The second scanning lens 42 is a long lens that has distortion (fθ characteristics) and extends along the main scanning direction (Y1-Y2 direction) like the first scanning lens 41. The second scanning lens 42 collects the laser beams D1 to D4 that have passed through the first scanning lens 41, and forms images on the scanned surfaces of the photosensitive drums 1a to 1d, respectively.

[0044] The pair of reflecting mirrors 49a reflect 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.

[0045] The laser light D1 collected by the first scanning lens 41 and the second scanning lens 42 is reflected by the reflecting mirror 49a and formed into an image on the scanned surface of the photosensitive drum 1a. The laser light D4 collected by the first scanning lens 41 and the second scanning lens 42 is reflected by the reflecting mirror 49a and formed into an image on the scanned surface of the photosensitive drum 1d.

[0046] The laser light D2 focused by the first scanning lens 41 and the second scanning lens 42 is reflected by the reflecting 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 reflecting mirrors 49b and 49c to form an image on the scanned surface of the photosensitive drum 1c.

[0047] The laser beams D1 to D4 reflected and deflected by the polygon mirror 45 pass through the first scanning lens 41 and the second scanning lens 42 and are focused on the scanned surfaces of the photosensitive drums 1a to 1d, respectively. As a result, beam spots are formed on the scanned surfaces of the photosensitive drums 1a to 1d. 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.

[0048] At this time, the laser beams D1 to D4 scan the scanned surfaces (circumferential surfaces) of the photoconductor drums (image carriers) 1a to 1d in the main scanning direction (Y1-Y2 direction) due to the rotation of the polygon mirror 45. Also, the laser beams D1 to D4 scan in the sub-scanning direction (Z1-Z2 direction) due to the rotation of the photoconductor drums 1a to 1d to form electrostatic latent images on the surfaces of the photoconductor drums 1a to 1d.

[0049] [3. Mounting configuration of reflecting mirror 49b] FIG. 5 is an oblique view of a pressure spring 50 (pressure-holding member) that presses and holds the reflection mirror 49b, and FIG. 6 is an enlarged partial cross-sectional view showing the vicinity of the reflection mirror 49b, illustrating the holding structure at one end side (Y2 side) of the reflection mirror 49b in the longitudinal direction.

[0050] The accommodation section 481 has a mirror holding section (holding section) 60 and a first spring support section (supporting section) 61 (see FIG. 6). The mirror holding section 60 and the first spring support section 61 protrude upward (Z1 direction) from the upper surface of the bottom wall section 481a. The mirror holding sections 60 are arranged at two locations on each end of the bottom wall section 481a in the main scanning direction (Y1-Y2 direction), for a total of four locations (see FIG. 3). That is, the housing 48 has a mirror holding section (holding section) 60 that holds a reflection mirror (optical element) 49b that constitutes the scanning optical system 120.

[0051] The mirror holding part 60 has an upper surface recessed downward to form a recess 601. The recess 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 reflecting mirror 49b in the left-right direction (X1-X2 direction). The second holding surface 601b faces the lower surface of the reflecting mirror 49b in the up-down direction (Z1-Z2 direction).

[0052] The first spring support parts 61 are disposed adjacent to each other on one side (Y2 side) of the longitudinal direction of the light outlets 483b, 483c, respectively, for a total of two positions. Each first spring support part 61 has a support protrusion 61a. Each support protrusion 61a protrudes in the left-right direction (X1-X2 direction) from a side surface of the first spring support part 61 (see FIG. 6).

[0053] That is, the housing 48 has a first spring support portion (support portion) 61. The first spring support portion 61 is formed facing the mirror holding portion 60, and supports a spring main body portion (main body portion) 51 of the pressure spring 50 described below. The first spring support portion (support portion) 61 is disposed on the periphery of through holes 483b, 483c penetrating the housing 48, and has a support protrusion 61a.

[0054] The support protrusion 61a protrudes from the outer surface of the first spring support portion (support portion) 61. In this embodiment, the support protrusion 61a extends in a direction approaching the mirror holding portion 60. At this time, the through holes 483b, 483c to which the support protrusion 61a is arranged are the emission ports 483b, 483c for emitting the laser beams D2, D3 to the outside of the housing 48.

[0055] Further, the tip of the supporting protrusion 61a is located inside the emission ports 483b and 483c in a cross section perpendicular to the longitudinal direction (Y1-Y2 direction) of the reflecting mirror 49b.

[0056] The reflection mirror 49b has both ends in the longitudinal direction (both ends in the Y1-Y2 direction) held by the mirror holding portion 60 (see FIG. 3). The reflection mirror 49b is fixed in the recess 601 via an adhesive 601c. One end in the longitudinal direction (Y2 side) of the reflection mirror 49b is pressed by a pressure spring 50. The pressure spring 50 is supported by a first spring support portion 61, and the reflection mirror 49b is stably held in the accommodation portion 481.

[0057] Specifically, the pressure spring (pressure holding member) 50 is formed by bending a metal plate, and has a spring main body (main body) 51, a first pressing portion (pressing portion) 52, and a second pressing portion (pressing portion) 53.

[0058] A pair of claws 51a are formed on the upper end of the spring main body 51, sandwiching the second pressing portion 53. The claws 51a are bent in a direction away from the second pressing portion 53. When the spring main body 51 is supported by the first spring support portion 61 (see FIG. 6), the claws 51a are disposed on the upper surface of the first spring support portion 61. This allows the pressing spring 50 to be stably supported by the first spring support portion 61.

[0059] The first pressing portion 52 is connected to the lower end of the spring body 51 via a first bent portion 50a. The first pressing portion 52 extends while inclining upward as it moves away from the spring body 51. The tip of the first pressing portion 52 is bent upward (in the Z1 direction) at a second bent portion 50b. The first pressing portion 52 is connected to the spring 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 tip of the first pressing portion 52 (on the tip side of the second bent portion 50b).

[0060] The second pressing portion 53 is connected to the upper end of the spring body 51 via the third bent portion 50c. The second pressing portion 53 extends from the spring body 51 in the same direction as the first pressing portion 52. The tip of the second pressing portion 53 is bent at the fourth bent portion 50d into an inverted V shape in side view. The second pressing portion 53 is connected to the spring 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 tip of the second pressing portion 53 (on the tip side of the third bent portion 50d).

[0061] The pressure spring 50 has a slit 50 e extending across the upper end of the spring body 51 and the base of the second pressure portion 53 .

[0062] The pressing spring 50 is inserted between the light reflecting surface of the reflecting mirror 49b and the first spring support portion 61. At this time, the lower end of the slit 50e abuts against the support protrusion 61a. That is, the support protrusion 61a contacts the periphery of the spring main body portion (main body portion) 51. This allows the pressing spring 50 to be easily positioned on the first spring support portion 61. The first pressing portion 52 contacts the light reflecting surface of the reflecting mirror 49b at the first pressing contact point 52a. The second pressing portion 53 contacts the upper surface of the reflecting mirror 49b at the second pressing contact point 53a.

[0063] As a result, the reflective mirror 49b is pressed against the first holding surface 60a by the biasing force of the first pressing portion 52 of the pressing spring 50. Also, the reflective mirror 49b is pressed against the second holding surface 60b by the biasing 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 reflective mirror (optical element) 49b held by the mirror holding portion (holding portion) 60 toward the mirror holding portion (holding portion) 60.

[0064] According to this configuration, the reflection mirror 49b can be held on the first holding surface 60a and the second holding surface 60b of the mirror holding portion 60 by using one pressure spring 50. Therefore, the reflection mirror 49b can be stably held without increasing the number of pressure springs 50.

[0065] In addition, when the housing portion 481 is sandwiched between dies from above and below (Z1-Z2 direction) and resin molded, the exit ports 483b and 483c can be used as holes in the dies. This makes it possible to easily mold the support protrusion 61a. By using the exit ports 483b and 483c formed on the optical paths of the laser beams D2 and D3, it is not necessary to newly form through holes in the housing 48 to form the support protrusion 61a. In addition, the exit ports 483b and 483c are covered by the dustproof glasses 70b and 70c, so there is no need to provide a new member to cover the through holes. Therefore, it is possible to provide an optical scanning device 5 that can stably hold the reflecting mirror (optical element) 49b while suppressing an increase in manufacturing cost, and an image forming device 100 including the same.

[0066] The tip of support protrusion 61a is located inside emission ports 483b, 483c in a cross section perpendicular to the longitudinal direction (Y1-Y2 direction) of reflection mirror 49b. This makes it easier to mold support protrusion 61a by using emission ports 483b, 483c as punching holes in a mold.

[0067] The tip of the support protrusion 61a may be bent in a direction approaching the through holes 483b, 483c. This allows the tip of the support protrusion 61a to be engaged with the lower end of the slit 50e. That is, the support protrusion 61a is engaged with the periphery of the spring main body portion (main body portion) 51. Therefore, the pressure spring 50 is stably supported by the first spring support portion (support portion) 61. Even if the tip of the support protrusion 61a is bent, the support protrusion 61a can be more easily molded by using the emission ports 483b, 483c as punch holes in a mold.

[0068] [4. Mounting configuration of reflecting mirror 49a] Fig. 7 is a perspective view of a pressure spring 80 (pressing and holding member) that presses and holds the reflection mirror 49a, and Fig. 8 is a cross-sectional view taken along line BB in Fig. 2. Fig. 9 is a partial cross-sectional view showing an enlarged view of the vicinity of the reflection mirror 49a, illustrating a holding structure on one end side (Y2 side) of the reflection mirror 49a in the longitudinal direction.

[0069] The accommodation portion 481 has a mirror holding portion 62 and a second spring support portion 63 (see FIG. 8). The mirror holding portion 62 and the second spring support portion 63 protrude upward (Z1 direction) from the upper surface of the bottom wall portion 481a. The mirror holding portions 62 are provided in four places in total, two at each end of the bottom wall portion 481a in the main scanning direction (Y1-Y2 direction).

[0070] The mirror holder 62 has a protruding holder 62a that protrudes from the side surface in the longitudinal direction (Y1-Y2 direction) of the reflecting mirror 49a. The protruding portion 62a has a protrusion 62b that protrudes from the upper surface of the tip portion. The upper end portion of the mirror holder 62 faces the side surface of the reflecting mirror 49a in the longitudinal direction (Y1-Y2 direction). The protrusion 62b faces the lower surface of the reflecting mirror 49a in the up-down direction (Z1-Z2 direction).

[0071] The second spring support portions 63 are formed in a part of the peripheral wall portion 481b on the Y2 side of the housing portion 481, and are arranged in pairs at both ends in the left-right direction (X1-X2 direction). A through hole 484 is formed in the left side X2 of the second spring support portion 63 arranged at the end on the left side X2. Also, a through hole 484 is formed in the right side X1 of the second spring support portion 63 arranged at the end on the right side X1. Each second spring support portion 63 has a support protrusion 63a. Each support protrusion 63a protrudes forward (Y1 direction) from the side surface of the second spring support portion 63 (see FIG. 9).

[0072] That is, the housing 48 has a second spring support portion (support portion) 63. The second spring support portion 63 is formed facing the mirror holding portion 62, and supports a spring main body portion (main body portion) 81 of the pressure spring 80 described below. The second spring support portion (support portion) 63 is disposed on the periphery of a through-hole 484 penetrating the housing 48, and has a support protrusion 63a.

[0073] The support protrusion 63a protrudes from the outer surface of the second spring support portion (support portion) 63. In this embodiment, the support protrusion 63a extends in a direction approaching the mirror holding portion 62. At this time, the support protrusion 63a is disposed facing the through hole 484.

[0074] In addition, the tip of the support protrusion 63a is located inside the through hole 484 in a cross section in the left-right direction (X1-X2 direction) perpendicular to the axial direction of the rotation axis J of the polygon mirror 45 included in the scanning optical system and the longitudinal direction (Y1-Y2 direction) of the reflecting mirror 49a.

[0075] The reflection mirror 49a has both ends in the longitudinal direction (both ends in the Y1-Y2 direction) held by mirror holders 62 (see FIG. 8). Specifically, the reflection mirror 49a is sandwiched in the longitudinal direction (Y1-Y2 direction) between the pair of mirror holders 62, and its lower surface is supported by protrusions 62b. One end (Y2 side) of the reflection mirror 49a in the longitudinal direction is pressed by a pressure spring 80. The pressure spring 80 is supported by a second spring support portion 63, and the reflection mirror 49a is stably held in the accommodation portion 481.

[0076] Specifically, the pressure spring (pressure holding member) 80 is formed by bending a metal plate, and has a spring main body portion (main body portion) 81, a pair of third pressure portions (pressure portions) 83, and a pair of bent support portions 84.

[0077] The spring main body 81 is supported by the second spring support portion 63 of the housing 48. The pair of bent support portions 84 are connected to the lower end portion of the spring main body 81 via a sixth bent portion 80f and extend downward. The bent support portions 84 are approximately parallel to the spring main body 81. The sixth bent portion 80f bends in the same direction as the extension direction of the third pressing portion 83. The bent support portions 84 are disposed on a step portion 63b that protrudes from the lower end portion of the second spring support portion 63 to the other side in the longitudinal direction (Y1 side).

[0078] The pair of third pressing portions 83 are connected to the upper end of the spring main body 81 via a fifth bent portion 80e. The pair of third pressing portions 83 extend while inclining downward as they move away from the spring main body 81. The third pressing portions 83 are connected to the spring main body 81 so as to be elastically deformable with the fifth bent portion 80e as a bending fulcrum. A hemispherical third pressing contact point 83a is formed at the tip of the third pressing portion 83.

[0079] The pressure spring 80 has a slit 85 formed therein, which extends across the upper end of the spring body 81 and the third pressure portion 83 .

[0080] The pressing spring 80 is inserted between the reflecting mirror 49a and the second spring support portion 63 in the longitudinal direction (Y1-Y2 direction). At the upper end of the spring main body portion 81, the support protrusion 63a of the pressing spring 80 abuts between the pair of third pressing portions 83. This allows the pressing spring 80 to be easily positioned on the second spring support portion 63. The pair of third pressing portions 83 are in contact with two upper surfaces at the third pressing contact points 83a, respectively, on one end side (Y2 side) of the reflecting mirror 49a in the longitudinal direction.

[0081] As a result, the reflection mirror 49a is pressed against the protrusion 62b by the biasing force of the third pressing portion 83 of the pressing spring 80. That is, the third pressing portion (pressing portion) 83 presses the reflection mirror (optical element) 49a held by the mirror holding portion (holding portion) 62 toward the mirror holding portion (holding portion) 63.

[0082] According to this configuration, the reflection mirror 49a can be held on the mirror holding portion 62 by using one pressure spring 80. Therefore, the reflection mirror 49a can be stably held without increasing the number of pressure springs 80.

[0083] Furthermore, when the housing portion 481 is sandwiched between dies from the front-rear direction (Y1-Y2 direction) and resin molded, the through-hole 484 can be used as a punch hole in the die. This allows the support protrusion 63a to be easily molded. Furthermore, the through-hole 484 is covered by the peripheral surface portion 482b. This makes it unnecessary to provide a new member for covering the through-hole 484 by using the cover portion 482. Therefore, it is possible to provide the optical scanning device 5 capable of stably holding the reflecting mirror (optical element) 49a while suppressing an increase in manufacturing cost, and the image forming apparatus 100 including the same.

[0084] In a cross section in the left-right direction (X1-X2 direction), the tip of the support protrusion 63a is located inside the through hole 484. This makes it easier to mold the support protrusion 63a by using the through hole 484 as a punch hole in a mold.

[0085] The tip of the support protrusion 63a may be bent in a direction approaching the through hole 484. This allows the tip of the support protrusion 63a to be engaged with the upper end of the spring main body 81. That is, the support protrusion 61a is formed on the periphery of the spring main body (main body) 81. Therefore, the pressure spring 80 is stably supported by the first spring support portion (support portion) 63. Even if the tip of the support protrusion 63a is bent, the support protrusion 63a can be more easily molded by utilizing the through hole 484 as a punch hole for a mold.

[0086] The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present invention. Fig. 10 is a partial cross-sectional view showing a modified mounting structure of the reflecting mirror 49b, in which a spring clamping portion (clamping portion) 64 may be provided. In this case, the housing portion 481 further has the 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.

[0087] The spring clamping portion 64 is disposed opposite the first spring support portion 61 in the left-right direction (X1-X2 direction). The spring main body portion 51 is clamped between the spring clamping portion 64 and the first spring support portion 61. In this embodiment, the spring clamping portion 64 is disposed in pair with the first pressing portion 52 sandwiched therebetween. That is, the housing 48 further has a spring clamping portion (clamping portion) 64 formed opposite the first spring support portion (support portion) 61, and the spring main body portion (main body portion) 51 is clamped between the first spring support portion (support portion) 61 and the spring clamping portion (clamping portion) 64. This allows the pressure spring 50 to be stably supported by the first spring support portion 61, and prevents the pressure spring 50 from rotating and coming off.

[0088] In addition, in each of the above embodiments, a configuration has been described in which the compression springs 50, 80 press and hold the reflection mirrors 49a, 49b. However, the optical elements pressed and held by the compression springs 50, 80 are not limited to the reflection mirrors 49a, 49b, and may be the first scanning lens 41, the second scanning lens 42, or the reflection mirror 49c.

[0089] In addition, a tandem color printer has been used as an example of the image forming apparatus 100 equipped with the optical scanning device 5, but the present invention is not limited to color printers and is also applicable to electrophotographic color image forming apparatuses such as color copiers and facsimiles, or electrophotographic monochrome image forming apparatuses such as monochrome printers and monochrome multifunction machines. [Industrial Applicability]

[0090] The present invention can be used in an optical scanning device that forms a latent image on a scanned surface by exposure scanning. [Explanation of symbols]

[0091] 1a to 1d Photoconductor drum (image carrier) 2a~2d Charger 3a~3d developing device 4a~4d Container 5 Optical Scanning Device 6a~6d Primary transfer roller 7b~7d Cleaning device 8 Intermediate transfer belt 9 Secondary transfer roller 10 Drive roller 11 Driven roller 12a Pick-up roller 12b Registration roller pair 13 Fixing section 16 Paper feed cassette 17, 18, 19, 20 Paper transport path 41 First scanning lens 42 Second scanning lens 44 Polygon Motor 45 Polygon Mirror 46 Light source section 48 Case 49a, 49b, 49c Reflecting mirror (optical element) 50, 80 Compression spring (pressure holding member) 50a First bend 50b 2nd bending part 50c 3rd bend 50d 3rd bend 50d 4th bend 50e slit 51 Spring body (body) 51a Claw part 52 First pressing part (pressing part) 52a First pressure contact 53 Second pressing part (pressing part) 53a Second pressure contact 60 Mirror holder (holder) 60a First holding surface 60b 2nd holding surface 61 First spring support part (support part) 61a, 63a Support protrusion 62 Mirror holder (holder) 62a Protrusion 62a Protruding holding part 62b Protrusion 63 Second spring support part (support part) 63b Step 64 Spring clamping part 70a~70d Dustproof glass 80e 5th bend 80f 6th bend 81 Spring body (body) 83 Third pressing part (pressing part) 83a Third pressure contact 84 Flexion support part 85 Slit 100 Image forming device 120 Scanning Optical System 481 Storage Unit 481a Bottom wall 481b Peripheral wall 482 Lid 482a Top section 482b Peripheral part 483a~483d Output port (through hole) 484 Through hole 601 Recess 601a 1st holding surface 601b Second holding surface 601c adhesive D1~D4 Laser light J Rotation axis S paper

Claims

1. a scanning optical system that scans the laser light and guides it onto an image carrier; a housing that houses the scanning optical system therein and has a holder that holds optical elements that constitute the scanning optical system; a pressing and holding member that presses the optical element and holds it in the holding portion; An optical scanning device for forming an electrostatic latent image by exposing a surface of the image carrier to light and reducing the charge, The pressing and holding member is A main body portion, a pressing portion connected to the main body portion and configured to press the optical element held by the holding portion toward the holding portion; having The housing includes: a support portion formed opposite to the holding portion and supporting the main body portion; The support portion is disposed on a periphery of a through hole penetrating the housing, a support protrusion protruding from an outer surface and contacting a periphery of the main body; The optical scanning device, wherein the through hole is an exit port for emitting the laser light to the outside of the housing.

2. the optical element is a reflection mirror that reflects the laser light, 2. The optical scanning device according to claim 1, wherein a tip of the support protrusion is located inside the through hole in a cross section perpendicular to the longitudinal direction of the reflecting mirror.

3. The support protrusion extends in a direction approaching the holding portion, 3. The optical scanning device according to claim 1, wherein a tip of the supporting protrusion is bent in a direction approaching the through hole.

4. The housing further includes a clamping portion formed opposite the support portion, 3. The optical scanning device according to claim 1, wherein the main body portion is sandwiched between the support portion and the clamping portion.

5. a scanning optical system that scans the laser light and guides it onto an image carrier; a housing that houses the scanning optical system therein and has a holder that holds optical elements that constitute the scanning optical system; a pressing and holding member that presses the optical element and holds it in the holding portion; An optical scanning device for forming an electrostatic latent image by exposing a surface of the image carrier to light and reducing the charge, The pressing and holding member is A main body portion, a pressing portion connected to the main body portion and configured to press the optical element held by the holding portion toward the holding portion; having The housing includes: a support portion formed opposite to the holding portion and supporting the main body portion; The support portion is disposed on a periphery of a through hole penetrating the housing, a support protrusion protruding from an outer surface and contacting a periphery of the main body; The housing includes: a housing portion having an open top and in which the scanning optical system is disposed; A lid portion for covering an upper surface of the storage portion; having the housing portion and the lid portion each have a wall portion that laterally surrounds the scanning optical system, The optical scanning device according to claim 1, wherein the through hole is formed in the wall of one of the housing portion or the lid portion and is closed by the wall of the other of the housing portion or the lid portion.

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

7. The support protrusion extends in a direction approaching the holding portion, 7. The optical scanning device according to claim 5, wherein a tip of the supporting protrusion is bent in a direction approaching the through hole.

8. One or more of the image carriers each having a photosensitive layer formed on a surface thereof; a charging device for charging the image carrier to a predetermined surface potential; 6. The optical scanning device according to claim 1, wherein the surface of the image carrier charged by the charging device is exposed to light to form an electrostatic latent image by attenuating the charge; An image forming apparatus comprising:

Images