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 light source unit, a polyhedral rotating mirror, a first scanning lens, a second scanning lens, and a housing unit. The light source unit has a plurality of light-emitting modules that emit laser light. The accommodating part accommodates the light source part, the polyhedral rotating mirror, the first scanning lens and the second scanning lens. The light-emitting module includes a light-emitting element that emits laser light, a coupling lens, and a bracket. The coupling lens converts the laser light emitted from the light-emitting element into light that is substantially parallel to the main scanning direction and is condensed in the sub-scanning direction. The light-emitting modules are arranged in the vertical direction between adjacent protruding parts, and the brackets are fixed to the protruding parts on the two sides through adhesives.

Description

Technical Field

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

[0002] A conventional optical scanning device includes a light source unit, a polygonal rotating mirror, a first scanning lens, a second scanning lens, and a storage unit (optical box). The light source unit is provided with a plurality of light-emitting modules (optical units) that emit laser light. The polygonal rotating mirror rotates around a rotation axis extending in the up-down direction, reflects the laser light emitted from the light source unit, and causes the laser light to scan the circumference of the image carrier along the main scanning direction. The first scanning lens focuses the laser light reflected by the polygonal rotating mirror. The second scanning lens forms an image of the laser light that has passed through the first scanning lens on the circumference of the image carrier. The storage unit stores the light source unit, the polygonal rotating mirror, the first scanning lens, and the second scanning lens.

[0003] The light-emitting module includes a light-emitting element, a lens, and a bracket. The light-emitting element emits laser light. The lens converts the laser light emitted from the light-emitting element into a direction substantially parallel to the main scanning direction. The bracket is formed into a cylindrical shape, extends in the light-emitting direction of the laser light, and holds the lens inside. The two light-emitting modules are unitized by a fixing component, and the fixing component is fixed to the receiving portion.

[0004] When the conventional technology is used, when the light emitting module is adjusted and fixed, it is difficult to rotate the light emitting module in the circumferential direction around the light emission direction of the laser or to adjust the position by tilting it in the vertical direction. Summary of the invention

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an optical scanning device capable of easily adjusting and fixing a light emitting module, and an image forming apparatus including the optical scanning device.

[0006] An optical scanning device according to one aspect of the present invention includes a light source unit, a polygonal rotating mirror, a first scanning lens, a second scanning lens, and a storage unit. The light source unit has a plurality of light-emitting modules that emit laser light. The polygonal rotating mirror rotates around a rotation axis extending in the up-down direction, reflects the laser light emitted from the light source unit, and causes the laser light to scan the circumference of the image carrier along the main scanning direction. The first scanning lens focuses the laser light reflected by the polygonal rotating mirror. The second scanning lens forms an image of the laser light passing through the first scanning lens on the circumference of the image carrier. The storage unit stores the light source unit, the polygonal rotating mirror, the first scanning lens, and the second scanning lens. The light-emitting module has a light-emitting element that emits laser light, a coupling lens, and a bracket. The coupling lens converts the laser light emitted from the light-emitting element into a light parallel to the main scanning direction and focused in the sub-scanning direction. The bracket is cylindrical, extends along the light emitting direction of the laser light, and holds the coupling lens inside. The storage unit has a bottom wall and a plurality of protrusions. The bottom wall extends in a direction orthogonal to the rotation axis. The protrusion protrudes upward from the upper surface of the bottom wall. The light emitting modules are arranged in a vertical direction between adjacent protrusions, and the brackets are fixed to the protrusions on both sides by adhesive.

[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 easily adjusting and fixing a light emitting module and an image forming apparatus including the optical scanning device.

[0008] Still 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

[0009] 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 cross-section diagram in. Figure 5 It is a perspective view showing the vicinity of the light source unit 46 of the optical scanning device 5 of the present invention in an enlarged manner. Figure 6 It is a perspective view of the light emitting modules 30K and 30Y of the optical scanning device 5 of the present invention. Figure 7 It is a perspective view of the light emitting modules 30C and 30M of the optical scanning device 5 of the present invention. Figure 8It is a side cross-sectional view of the light emitting modules 30K and 30Y of the optical scanning device 5 of the present invention. Fig. 9 It is a side cross-sectional view of the light emitting modules 30C and 30M of the optical scanning device 5 of the present invention. Fig.10 It is a cross-sectional view perpendicular to the main scanning direction of the light source unit 46 of the optical scanning device 5 of the present invention. DETAILED DESCRIPTION

[0010] [1. Structure of image forming apparatus] 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 FIG. 1 , 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 side of the image forming apparatus 100 shown in the drawing as the front side (front). In addition, the left-right direction (X1-X2 direction) is defined with the front side 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).

[0011] 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. The photosensitive drums 1a to 1d use 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. The photosensitive drums 1a to 1d are arranged in tandem corresponding to the respective colors of yellow, cyan, magenta, and black.

[0012] The developing device 3a, the charging device 2a and the cleaning device 7a are arranged around the photosensitive drum 1a. Similarly, the developing devices 3b to 3d, the charging devices 2b to 2d and the cleaning devices 7b to 7d are arranged around the photosensitive drums 1b to 1d. In addition, the optical scanning device 5 is arranged above the developing devices 3a to 3d at Z1.

[0013] 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 opposite 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.

[0014] 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 charge the surfaces of the photosensitive drums 1a to 1d uniformly.

[0015] 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 that are similarly charged by the chargers 2a to 2d, based on image data such as text and patterns input from a personal computer or the like to the image input unit. Thus, an electrostatic latent image is formed on the surfaces of the photosensitive drums 1a to 1d.

[0016] 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. 4 ). Figure 4 The storage unit 481 stores the scanning optical system therein. The storage unit 481 will be described in detail later.

[0017] Lasers D1 to D4 are irradiated onto the surfaces of the photosensitive drums 1a to 1d from the downstream side 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.

[0018] 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 driving the intermediate transfer belt 8 to the Figure 1 Cycle in clockwise direction.

[0019] The photosensitive drums 1a to 1d are arranged adjacent to each other along the conveyance direction above Z1 of the intermediate transfer belt 8. The photosensitive drums 1a to 1d are in contact with the intermediate transfer belt 8, respectively.

[0020] The primary transfer rollers 6a to 6d face the photosensitive drums 1a to 1d respectively via the intermediate transfer belt 8. The primary transfer rollers 6a to 6d are in pressure contact with the intermediate transfer belt 8 and form primary transfer sections together with the photosensitive drums 1a to 1d. In these primary transfer sections, the toner images are transferred to the intermediate transfer belt 8.

[0021] 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. As a result, a full-color toner image is formed on the surface of the intermediate transfer belt 8, in which the four color toner images of magenta, cyan, yellow, and black are superimposed in a predetermined positional relationship.

[0022] The secondary transfer roller 9 faces the driving roller 10 across 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, the belt cleaning device (not shown) cleans the toner remaining on the intermediate transfer belt 8.

[0023] A paper feed cassette 16 is disposed at the lower portion of the image forming apparatus 100 . The paper feed cassette 16 can store a plurality of sheets of paper S. A paper conveyance path 19 is disposed to the right X1 of the paper feed cassette 16 .

[0024] 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 paper S on which the image is formed. The paper conveying path 20 conveys the paper S after the fixing process to the paper discharge unit 17.

[0025] The paper S stored in the paper feed cassette 16 is fed one sheet at a time toward the paper conveyance path 19 by the pickup roller 12 a .

[0026] The registration roller pair 12b grasps the timing of the image forming operation on the intermediate transfer belt 8 and the paper feeding operation to the secondary transfer section, and conveys the paper S to the secondary transfer section. The full-color toner image on the intermediate transfer belt 8 is secondarily transferred by the secondary transfer roller 9 to which the secondary transfer voltage is applied to the paper S conveyed to the secondary transfer section. The paper S to which the full-color toner image is transferred is conveyed toward the fixing section 13.

[0027] The fixing section 13 includes a fixing belt heated by a heater, a fixing roller internally 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 presses the paper S to which the toner image is transferred. Thus, a fixing process is performed. The paper S to which the toner image is fixed in the fixing section 13 is turned over on the front and back sides in the paper conveying passage 18 as needed. Thereafter, the paper S is conveyed to the secondary transfer section again by means of the registration roller pair 12b, and a new toner image is secondary transferred on the back side of the paper S by the secondary transfer roller 9, and fixed by 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.

[0028] [2. Structure of optical scanning device] Figure 2 , Figure 3 is a perspective view of the optical scanning device 5, Figure 3 Indicates a state where the cover portion 482 is removed. Figure 4 yes Figure 2 AA cross-section diagram in. Figure 4The 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 in the figure.

[0029] In the following description, the main scanning direction (Y1-Y2 direction) is the long side direction of the reflection mirrors 49a to 49c. In addition, the main scanning direction (Y1-Y2 direction) is consistent with the direction in which the rotation axis of the photosensitive drums 1a to 1d extends and the front-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 reflection mirrors 49a to 49c.

[0030] The optical scanning device 5 outputs (irradiates) multiple types (four types in this embodiment) of laser light D1 to D4 modulated according to 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.

[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 reflection mirrors 49 a , 49 b , and 49 c , and a housing 48 (accommodating portion 481 ).

[0032] The housing 48 includes a housing portion 481 and a cover portion 482. The housing portion 481 is formed in a substantially quadrilateral shape in a plan view and houses 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 reflection mirrors 49a, 49b, 49c.

[0033] The storage portion 481 includes a bottom wall portion 481a, a peripheral wall portion 481b, and a plurality of protrusions 90, 91, and 92. 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 ejection ports 483a to 483d extending in the vertical direction (see FIG. 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 are emitted to the outside of the housing 48 through the ejection ports 483a to 483d, and are respectively injected into the corresponding photosensitive drums 1a to 1d. The ejection ports 483a to 483d are respectively covered by dustproof glasses 70a to 70d. This prevents dust from entering the housing 48.

[0034] The protrusions 90, 91, and 92 protrude upward from the upper surface of the bottom wall portion 481a. The protrusions 90, 91, and 92 hold the light source portion 46. The shapes of the protrusions 90, 91, and 92 will be described in detail later.

[0035] 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 inside.

[0036] The cover portion 482 includes a top surface portion 482a and a peripheral surface portion 482b. The top surface portion 482a covers the upper surface of the opening of the housing portion 481. The peripheral surface portion 482b extends downward from the outer periphery of the top surface portion 482a and covers a portion of the peripheral wall portion 481b from the radially outer side.

[0037] The light source unit 46 includes a plurality of light emitting modules 30Y, 30C, 30M, and 30K that emit laser light. Laser light D1 to D4 corresponding to the respective colors of Y (yellow), C (cyan), M (magenta), and K (black) are output from the light emitting modules 30Y, 30C, 30M, and 30K, respectively. The laser light D1 to D4 emitted from the light emitting modules 30Y, 30C, 30M, and 30K, respectively, is irradiated toward the polygon mirror 45. The laser light D1 to D4 forms a line image near the deflection surface of the polygon mirror 45.

[0038] The polygon mirror 45 rotates around a rotation axis J extending in the vertical direction (Z1-Z2 direction) to reflect the laser beams D1-D4 emitted from the light source 46 so as to scan the peripheral surfaces of the photosensitive drums (image carriers) 1a-1d in the main scanning direction.

[0039] The polygon mirror 45 is composed of a plurality of reflecting surfaces. In the present embodiment, the polygon mirror 45 is a polygon mirror formed in a quadrangular prism shape. The lasers D1 and D2 incident on the polygon mirror 45 are deflected and scanned by any of the reflecting surfaces driven by rotation, and are reflected in the left direction (X2 direction) by the reflecting surface of the polygon mirror 45, and are guided to the first scanning lens 41 and the second scanning lens 42. On the other hand, the lasers D3 and D4 incident on the polygon mirror 45 are deflected and scanned by any of the reflecting surfaces driven by rotation, and are reflected in the right direction (X1 direction) by the reflecting surface of the polygon mirror 45, and are 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 (fθ characteristics) and is a long lens extending in the main scanning direction (Y1-Y2 direction). The first scanning lens 41 condenses 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 (fθ characteristics) 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 to D4 that has passed through the first scanning lens 41, and forms images on the scanned surfaces of the photosensitive drums 1a to 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, and forms 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, and forms 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 are scanned at a constant speed on the scanned surfaces of the photosensitive drums 1a to 1d.

[0047] At this time, the lasers D1 to D4 scan the scanned surfaces (peripheral surfaces) of the photosensitive drums (image carriers) 1a to 1d along the main scanning direction (Y1-Y2 direction) by the rotation of the polygon mirror 45. In addition, the lasers D1 to D4 scan along 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. Structure of light source unit] Figure 5 is a perspective view showing an enlarged view of the light source unit 46. Figure 6 is a perspective view of the light emitting modules 30K and 30Y. Figure 7It is a perspective view of the light emitting modules 30C and 30M. Figure 8 is a side cross-sectional view of the light emitting modules 30K and 30Y, Fig. 9 It is a side cross-sectional view of the light emitting modules 30C and 30M.

[0049] The light source unit 46 is composed of light emitting modules 30Y, 30C, 30M, and 30K. The light emitting modules 30K and 30C are arranged on the right side (X1 side) of the rotation axis J when viewed from the polygon mirror 45 along the main scanning direction (Y1-Y2 direction), and the light emitting module 30C is arranged on the lower side (Z2 side) of the light emitting module 30K. The light emitting modules 30Y and 30M are arranged on the left side (X2 side) of the rotation axis J when viewed from the polygon mirror 45 along the main scanning direction (Y1-Y2 direction), and the light emitting module 30M is arranged on the lower side (Z2 side) of the light emitting module 30Y.

[0050] In addition, the light emitting modules 30K and 30Y arranged on the upper side of the light emitting modules 30Y, 30C, 30M, and 30K have the same shape, and only the color of the laser light emitted from the light emitting element 35 is different. In addition, the light emitting modules 30C and 30M arranged on the lower side have the same shape, and only the color of the laser light emitted from the light emitting element 35 is different. In addition, the light emitting modules 30K and 30Y and the light emitting modules 30C and 30M differ only in the shape of the bracket 33.

[0051] The light emitting modules 30Y, 30C, 30M, and 30K include a light emitting element 35 that emits any one of the laser beams D1 to D4, a coupling lens 32, and a bracket 33. In the present embodiment, the laser beam D1 is emitted from the light emitting element 35 of the light emitting module 30K. In addition, the laser beam D2 is emitted from the light emitting element 35 of the light emitting module 30C. In addition, the laser beam D3 is emitted from the light emitting element 35 of the light emitting module 30M. In addition, the laser beam D4 is emitted from the light emitting element 35 of the light emitting module 30Y.

[0052] The coupling lens 32 converts each laser light D1 to D4 emitted from the light emitting element 35 into a light beam that is substantially parallel to the main scanning direction and focused in the sub-scanning direction. As a result, the laser light D1 to D4 form a line image near the deflection surface of the polygon mirror 45. For example, the coupling lens 32 is a deformed shape and is composed of a single lens formed by a mold.

[0053] The bracket 33 extends along the light emitting direction of the laser (direction A), holds the coupling lens inside, and is cylindrical. The bracket 33 is composed of a lens holder 331, a laser holder 332, and an element holder 333. The bracket 33 is a resin molded product, and is suitable for using a lightweight and heat-resistant synthetic resin (such as a mixed material of ABS resin and PC resin).

[0054] The laser holder 332 extends along the light emitting direction (direction A) of the laser light, and has an aperture section 34 therein for narrowing the optical path of the laser light. The aperture section 34 enables the laser light to obtain a desired beam spot diameter.

[0055] The lens holder 331 is fixed to one end of the laser holder 332 in the light emitting direction (direction A), and holds the coupling lens 32 therein. The lens holder 331 has an opening 331a, and the laser light passing through the coupling lens 32 is emitted to the outside of the bracket 33 through the opening 331a.

[0056] The element holder 333 is fixed to the other end of the laser holder 332 in the light emitting direction (direction A), and holds the light emitting element 35 therein. The laser holder 332 and the element holder 333 are oriented three-dimensionally and fixed at a predetermined position by an adhesive.

[0057] The shape of the laser bracket 332 is different in the light emitting modules 30Y, 30K and the light emitting modules 30C, 30M. That is, the laser bracket 332 (bracket 33) of the light emitting modules 30K, 30Y arranged on the upper side of the light emitting modules 30Y, 30C, 30M, 30K arranged in the up-down direction has an annular portion 332a. The annular portion 332a protrudes from the outer peripheral surface of the laser bracket 332 (bracket 33) and is formed in an annular shape. A plurality of annular portions 332a are arranged in the light emitting direction (direction A) of the laser. By forming the annular portion 332a, it is possible to suppress the occurrence of shrinkage cavities when the laser bracket 332 (bracket 33) is resin-molded, and the outermost diameter of the laser bracket 332 (bracket 33) can be formed larger.

[0058] By forming the annular portion 332a, the outermost diameter D2 of the laser holder 332 (bracket 33) of the light emitting modules 30K and 30Y arranged on the upper side among the light emitting modules 30Y, 30C, 30M, and 30K arranged in the vertical direction is larger than the outermost diameter D1 of the laser holder 332 (bracket 33) of the light emitting modules 30C and 30M arranged on the lower side (see FIG. Fig.10 ). In addition, the outermost diameters D1 and D2 are the outermost diameters in the region of the laser holder 332 (bracket 33) to which the adhesive 95 described later is applied (the region sandwiched between the protrusions 90 and 91 or between the protrusions 91 and 92).

[0059] [4. Method for fixing the light emitting module] Fig.10 4 is a cross-sectional view perpendicular to the main scanning direction (Y1-Y2 direction) of the light source unit 46. The bottom wall portion 481a of the storage portion 481 has protrusions 90, 91, 92 (see FIG. 4 ) protruding from the upper surface toward the upper side (Z1 direction). Figure 3). In the present embodiment, the protrusions 90, 91, and 92 have surfaces orthogonal to the left-right direction (X1-X2 direction), and are arranged along the left-right direction (X1-X2 direction). When viewed from the polygon mirror 45 along the main scanning direction (Y1-Y2 direction), the protrusion 91 is arranged at a position that coincides with the rotation axis J, and the protrusion 90 is arranged on the left side (X2 direction) of the protrusion 91. The protrusion 92 is arranged on the right side (X1 direction) of the protrusion 91.

[0060] The light emitting modules 30Y and 30M are arranged along the vertical direction (Z1-Z2 direction) between adjacent protrusions 90 and 91, and the bracket 33 is fixed to the protrusions 90 and 91 on both sides by an adhesive 95. The light emitting modules 30K and 30C are arranged along the vertical direction (Z1-Z2 direction) between adjacent protrusions 91 and 92, and the bracket 33 is fixed to the protrusions 91 and 92 on both sides by an adhesive 95.

[0061] The adhesive 95 is made of, for example, an ultraviolet curing resin. Thus, after the positions of the light emitting modules 30Y, 30C, 30M, and 30K are adjusted, they can be easily fixed to the protruding portions 90 , 91 , and 92 .

[0062] The light emitting modules 30Y, 30C, 30M, 30K are directly fixed to the protrusions 90, 91, 92 by the adhesive 95, so the light emitting modules 30Y, 30C, 30M, 30K can be easily fixed while adjusting the orientation. As a result, the orientation of the lasers D1 to D4 emitted from the light emitting modules 30Y, 30C, 30M, 30K can be finely adjusted three-dimensionally in the left-right direction (X1-X2 direction), the front-back direction (Y1-Y2 direction), and the up-down direction (Z1-Z2 direction). As a result, the positions of the optical axes of the lasers D1 to D4 can be adjusted.

[0063] In addition, by moving the light emitting modules 30Y, 30C, 30M, and 30K in the front-to-back direction (Y1-Y2 direction) along the light emitting direction (A direction) of the lasers D1 to D4, the focusing position in the sub-scanning direction of the deflection surface of the polygonal mirror 45 can be adjusted.

[0064] Furthermore, by rotating the light emitting modules 30Y, 30C, 30M, and 30K in the circumferential direction around the optical axis extending in the light emitting direction (direction A) of the laser beams D1 to D4, the optical axes of the laser beams D1 to D4 can be adjusted.

[0065] The refractive index of the coupling lens 32 varies due to temperature changes during mold molding, and there is a possibility that the focusing position of the light focused on the deflection surface of the polygon mirror 45 is deviated. At this time, by finely adjusting and fixing the positions and orientations of the light emitting modules 30Y, 30C, 30M, and 30K, the focusing position of the light focused on the deflection surface of the polygon mirror 45 can be adjusted to an appropriate position. Therefore, the positions of the light emitting modules 30Y, 30C, 30M, and 30K can be easily adjusted and fixed to appropriate positions.

[0066] In addition, as described above, the laser bracket 332 and the element bracket 333 can change their orientation three-dimensionally and are fixed at a predetermined position by an adhesive. Therefore, before adjusting the orientation of the light-emitting modules 30Y, 30C, 30M, and 30K, the positional relationship between the laser bracket 332 and the element bracket 333 can be adjusted to adjust the focusing position of the deflection surface of the polygon mirror 45 to an appropriate position.

[0067] The polygon mirror 45, the first scanning lens 41, the second scanning lens 42, and the reflectors 49a, 49b, and 49c are fixed to the storage portion 481, and the positions of the light emitting modules 30Y, 30C, 30M, and 30K are adjusted while confirming the optical axis position and the beam diameter in the main scanning direction. In this way, parallel light can be reliably incident on the first scanning lens 41, and the focusing position in the main scanning direction can be adjusted to an appropriate position. In addition, the positions of the light emitting modules 30Y, 30C, 30M, and 30K can be adjusted while confirming the laser light formed on the surface of the photosensitive drums 1a to 1d with a camera.

[0068] The width L2 between the protrusions 90 and 91 in the region sandwiching the light emitting module 30Y arranged on the upper side is larger than the width L2 between the protrusions 90 and 91 in the region sandwiching the light emitting module 30M arranged on the lower side. Specifically, the maximum width L2 of the upper end portion between the protrusions 90 and 91 to which the light emitting module 30Y arranged on the upper side is fixed among the light emitting modules 30Y, 30C, 30M, and 30K arranged in the vertical direction is larger than the maximum width L1 of the lower end portion between the protrusions 90 and 91 to which the light emitting module 30M arranged on the lower side is fixed. Similarly, the maximum width of the upper end portion between the protrusions 91 and 92 to which the light emitting module 30K is fixed is larger than the maximum width of the lower end portion between the protrusions 91 and 92 to which the light emitting module 30C arranged on the lower side is fixed.

[0069] In more detail, the upper end and the lower end between the protrusions 90 and 91 have curved portions 96a and 97a and recessed portions 96b and 97b on the opposing surfaces in the left-right direction (X1-X2 direction). The curved portions 96a and 97a are formed by bending along the shape of the bracket 33. The recessed portion 96b is formed by further recessing the opposing surfaces of the protrusions 90 and 91 in the left-right direction (X1-X2 direction) above the curved portion 96a. The recessed portion 97b is formed by further recessing the opposing surfaces of the protrusions 90 and 91 in the left-right direction (X1-X2 direction) above the curved portion 97a. The width L2 of the recessed portion 96b in the left-right direction (X1-X2 direction) is greater than the width L1 of the recessed portion 97b in the left-right direction (X1-X2 direction). In the present embodiment, the adhesive 95 is disposed in the recessed portions 96b and 97b.

[0070] At this time, the outermost diameter D2 of the laser bracket 332 (bracket 33) of the light emitting modules 30K and 30Y arranged on the upper side is larger than the outermost diameter D1 of the laser bracket 332 (bracket 33) of the light emitting modules 30C and 30M arranged on the lower side. As a result, the gap between the laser bracket 332 (bracket 33) and the protrusions 90, 91, 92 can be made uniform at the light emitting modules 30Y, 30C, 30M, and 30K arranged above and below. Therefore, the unevenness of the thickness of the adhesive 95 existing in the gap between the laser bracket 332 (bracket 33) and the protrusions 90, 91, and 92 can be reduced. As a result, each light emitting module 30Y, 30C, 30M, and 30K can be stably fixed after the position is adjusted.

[0071] In addition, in the present embodiment, the width L1 of the concave portion 97b in the left-right direction (X1-X2 direction) is larger than the outermost diameter D1 of the region of the laser holder 332 (bracket 33) in contact with the adhesive 95. As a result, the light emitting modules 30M and 30C are less likely to contact the protrusions 90, 91, and 92 when the orientation is finely adjusted. Therefore, the adjustable movable region of the light emitting modules 30C and 30M can be expanded.

[0072] Similarly, the width L2 of the recess 96b in the left-right direction (X1-X2 direction) is larger than the outermost diameter D2 of the region of the laser holder 332 (bracket 33) in contact with the adhesive 95. This can expand the adjustable movable range of the light emitting modules 30K and 30Y.

[0073] In addition, the present invention is not limited to the above-mentioned embodiments, and various changes can be made within the scope of the purpose of the present invention. For example, as long as the shape of the bracket 33 of the light-emitting module arranged on the upper side and the lower side is the same as that of the present embodiment, the arrangement of the colors of the lasers D1 to D4 emitted from the light-emitting modules 30Y, 30C, 30M, and 30K is not particularly limited. For example, the light-emitting module on the upper side can also emit C (cyan) or M (magenta) lasers.

[0074] The present invention can be applied to 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 light source unit having a plurality of light emitting modules for emitting laser light; A polygonal mirror rotates around a rotation axis extending in the up-down direction to reflect the laser light emitted from the light source so that the laser light scans the peripheral surface of the image carrier in the main scanning direction; A first scanning lens, for focusing the laser light reflected by the polygonal mirror; A second scanning lens is used to image the laser beam having passed through the first scanning lens on the peripheral surface of the image carrier; as well as a receiving portion for receiving the light source portion, the polygon mirror, the first scanning lens and the second scanning lens, The light emitting module comprises: A light emitting element, emitting the laser light; A coupling lens converts the laser light emitted from the light emitting element into light parallel to the main scanning direction and focused in the sub-scanning direction; and The cylindrical bracket extends in the light emitting direction of the laser and holds the coupling lens inside. The receiving portion comprises: a bottom wall portion extending in a direction orthogonal to the rotation axis; as well as A plurality of protrusions protrude upward from the upper surface of the bottom wall portion, The light emitting modules are arranged in a vertical direction between adjacent protrusions, and the bracket is fixed to the protrusions on both sides by an adhesive.

2. The optical scanning device according to claim 1, characterized in that: The maximum width between the protrusions for fixing the light emitting module arranged on the upper side among the light emitting modules arranged in a vertical direction is larger than the maximum width between the protrusions for fixing the light emitting module arranged on the lower side.

3. The optical scanning device according to claim 1 or 2, characterized in that: The outermost diameter of the bracket in the region contacting the adhesive of the upper light emitting module among the light emitting modules arranged in the vertical direction is larger than the outermost diameter of the bracket in the region contacting the adhesive of the lower light emitting module.

4. The optical scanning device according to claim 3, characterized in that: The bracket of the light emitting module arranged on the upper side among the light emitting modules arranged in a vertical direction has a ring-shaped portion protruding from the outer peripheral surface and formed in a ring shape, and a plurality of the ring-shaped portions are arranged in the light emitting direction of the laser light.

5. The optical scanning device according to claim 1 or 2, characterized in that: The adhesive is composed of an ultraviolet curing resin.

6. An image forming device, characterized in that: include: The optical scanning device according to claim 1 or 2; as well as One or more of the image carriers has a photosensitive layer formed on the surface; as well as a charging device for charging the image carrier to a predetermined surface potential, The optical scanning device exposes the surface of the image carrier charged by the charging device to form an electrostatic latent image that attenuates the charge.

Images