Scanning optical device

Abstract

When attaching the mirror of a scanning optical device to the frame, the mirror can be easily guided to the mounting position on the frame. [Solution] The scanning optical device comprises a light source, a deflector, a scanning optical system, and a frame 100. The scanning optical system has a mirror that reflects the beam deflected by the polygon mirror. The frame 100 is to which the light source, deflector, and scanning optical system are mounted. The mirror (first mirror 81Y) has a first surface F1 having a reflective surface extending in the longitudinal direction and in the short direction perpendicular to the longitudinal direction, and a second surface F2 facing the short direction. The frame 100 has a first contact portion 131A that contacts the first surface F1, a second contact portion 131C that contacts the second surface F2, and a plurality of guide surfaces (first guide surface 131D). The plurality of guide surfaces are further away from the second surface F2 than the second contact portion 131C in the short direction. The plurality of guide surfaces extend in the thickness direction of the mirror.

Description

Technical Field

[0001] The present invention relates to a scanning optical device.

Background Art

[0002] Conventionally, as a scanning optical device, one including a light source, a deflector, a scanning optical system, and a frame is known (Patent Document 1). The scanning optical system has a mirror that reflects the beam deflected by the deflector. When assembling the mirror to the frame, after adjusting the assembly angle, the photocurable resin disposed between the mirror and the frame is cured by irradiating light.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when assembling the mirror to the frame, there is a problem that the mirror may move in a direction different from the assembling direction and may be displaced with respect to the mounting position of the frame.

[0005] Therefore, an object of the present invention is to easily guide the mirror to the mounting position of the frame when mounting the mirror to the frame.

Means for Solving the Problems

[0006] A scanning optical device for achieving the above-described problems is used in an image forming apparatus and includes a light source, a deflector, a scanning optical system, and a frame. The light source has a semiconductor laser and a coupling lens that converts the light emitted from the semiconductor laser into a beam. The deflector has polygon mirrors. The deflector deflects the beam emitted from the light source in the main scanning direction. The scanning optical system has mirrors that reflect the beam deflected by the polygon mirrors. The scanning optical system images the beam deflected by the deflector onto the surface to be scanned. The frame is fitted with a light source, a deflector, and a scanning optical system. The mirror has a first surface with reflective surfaces extending in the longitudinal direction and in the short direction perpendicular to the longitudinal direction, and a second surface facing the short direction. The frame has a first contact portion that contacts the first surface, a second contact portion that contacts the second surface, and a plurality of guide surfaces. The multiple guide surfaces are further away from the second contact area than the second surface in the shorter direction and extend in the thickness direction of the mirror.

[0007] Since the multiple guide surfaces are further away from the second surface than the second contact portion in the short direction and extend in the thickness direction of the mirror, when assembling a scanning optical device, the multiple guide surfaces can easily guide the mirror to the mounting position on the frame when attaching the mirror to the frame.

[0008] Furthermore, the second contact portion may be positioned corresponding to one end and the other end of the mirror in the longitudinal direction. In the longitudinal direction, multiple guide surfaces may be located between two second contact portions.

[0009] Multiple guide surfaces are positioned between the two second contact points, making it easier to guide the mirror.

[0010] Furthermore, the first contact portion may have an arc-shaped surface when viewed along its longitudinal direction.

[0011] Because the first contact area has an arc-shaped surface, the angle of the mirror can be easily adjusted.

[0012] Furthermore, the system may further include a photocurable resin positioned alongside the first contact portion in the shorter direction and placed between the mirror and the frame.

[0013] Because a light-curing resin is placed between the mirror and the frame, the angle of the mirror can be adjusted and then fixed in place.

[0014] It may also have a spring that engages with the frame and biases the mirror toward the first contact point. The spring may have an opening in a position that overlaps with the light-curing resin when viewed along the thickness direction of the mirror.

[0015] Because it has a spring that engages with the frame and biases the mirror toward the first contact point, the mirror can be temporarily fixed to the frame. Furthermore, since the spring has an opening in a position where it overlaps with the photocurable resin, the photocurable resin can be cured by shining light through the opening.

[0016] The frame may also include a main frame and a subframe that is separable from the main frame and has an adhesive portion and a first contact portion to which a photocurable resin is fixed.

[0017] Since the frame consists of a main frame and a subframe having a first contact portion, the mirror can be easily removed from the main frame by removing the subframe from the main frame.

[0018] Furthermore, in the thickness direction, the dimensions of the guide surface may be greater than the thickness of the mirror.

[0019] Because the dimensions of the guide surface are larger than the thickness of the mirror, the mirror can be guided over a long distance when being installed.

[0020] Furthermore, in the thickness direction, the dimensions of the second contact portion may be smaller than the thickness of the mirror. [Effects of the Invention]

[0021] According to the present invention, when attaching the mirror of the scanning optical device to the frame, the mirror can be easily guided to the attachment position of the frame.

Brief Description of the Drawings

[0022] [Figure 1] It is a diagram showing an image forming apparatus. [Figure 2] It is a perspective view showing a scanning optical device. [Figure 3] It is a cross-sectional view taken along the line X-X of FIG. 2. [Figure 4] It is a cross-sectional view taken along the line Y-Y of FIG. 2. [Figure 5] It is a perspective view of the frame. [Figure 6] It is an exploded perspective view of the main frame, sub-frame, mirror and spring. [Figure 7] It is a diagram for explaining the positional relationship between the first mirror and the first attachment portion. [Figure 8] It is a cross-sectional view taken along the line A-A (a) and a cross-sectional view taken along the line B-B (b). [Figure 9] It is a diagram (a), (b), (c) showing the attachment procedure of the mirror.

Embodiments for Carrying Out the Invention

[0023] Next, embodiments will be described. As shown in FIG. 1, the image forming apparatus 1 is an electrophotographic image forming apparatus. In the present embodiment, the image forming apparatus 1 is a color laser printer. The image forming apparatus 1 includes a main body housing 2, a sheet feeding unit 3, a scanning optical device 4, a process unit PU, a fixing device 8, and a sheet discharging unit 9.

[0024] The main body housing 2 has a front cover 2A and a discharge tray 2B. The front cover 2A opens and closes the opening on the front side of the main body housing 2.

[0025] The sheet supply unit 3 is located at the bottom of the main body housing 2. The sheet supply unit 3 comprises a sheet tray 3A and a sheet supply mechanism 3B. The sheet tray 3A holds sheets S such as paper. The sheet supply mechanism 3B supplies the sheets S in the sheet tray 3A between the photosensitive drum 5A and the transfer belt 7C.

[0026] The scanning optical device 4 is located at the top of the main housing 2. The scanning optical device 4 emits a beam, indicated by the dashed line, to expose the surface of the photosensitive drum 5A.

[0027] The process unit PU is located within the main housing 2, between the sheet tray 3A and the scanning optical device 4. The process unit PU forms a toner image on the sheet S. The process unit PU comprises a drum unit 5, four developing cartridges 6, and a transfer unit 7.

[0028] The drum unit 5 is detachable from the main body housing 2 through an opening in the main body housing 2, which is opened by opening the front cover 2A. The drum unit 5 has four photosensitive drums 5A, four chargers 5B, and a drum frame 5C. The drum frame 5C supports the photosensitive drums 5A and the chargers 5B.

[0029] In this embodiment, the photosensitive drum 5A includes a photosensitive drum 5AY on which a yellow toner image is formed, a photosensitive drum 5AM on which a magenta toner image is formed, a photosensitive drum 5AC on which a cyan toner image is formed, and a photosensitive drum 5AK on which a black toner image is formed. The four photosensitive drums 5A are arranged from front to back, in other words, from upstream to downstream in the conveying direction of the sheet S, in the order of photosensitive drum 5AY, photosensitive drum 5AM, photosensitive drum 5AC, and photosensitive drum 5AK.

[0030] The developing cartridge 6 is detachable from the drum frame 5C of the drum unit 5. Each developing cartridge 6 comprises a developing roller 6A, a supply roller 6B, a layer thickness regulating blade 6D, a toner storage section 6E for storing toner, and an agitator 6F.

[0031] The agitator 6F stirs the toner in the toner storage section 6E. The agitator 6F also supplies the toner from the toner storage section 6E to the supply roller 6B. The supply roller 6B supplies the toner to the developer roller 6A. The layer thickness regulating blade 6D regulates the thickness of the toner on the developer roller 6A to a constant thickness.

[0032] The developer cartridge 6 contains toners of different colors. In this embodiment, the developer cartridge 6 includes a developer cartridge 6Y containing yellow toner, a developer cartridge 6M containing magenta toner, a developer cartridge 6C containing cyan toner, and a developer cartridge 6K containing black toner.

[0033] The transfer unit 7 is located between the sheet tray 3A and the drum unit 5. The transfer unit 7 comprises a drive roller 7A, a driven roller 7B, a transfer belt 7C, and four transfer rollers 7D. The transfer belt 7C is an endless belt. The drive roller 7A and the driven roller 7B rotate the transfer belt 7C. The transfer rollers 7D are located inside the transfer belt 7C. The transfer rollers 7D sandwich the transfer belt 7C between themselves and the photosensitive drum 5A.

[0034] The fixing device 8 is located behind the drum unit 5. The fixing device 8 comprises a heating roller 8A and a pressure roller 8B. The heating roller 8A heats the sheet S. The pressure roller 8B sandwiches the sheet S between itself and the heating roller 8A.

[0035] The charger 5B charges the surface of the photosensitive drum 5A. The scanning optical device 4 emits a beam to expose the surface of the photosensitive drum 5A. This forms an electrostatic latent image on the photosensitive drum 5A. The developing roller 6A supplies toner to the photosensitive drum 5A. This forms a toner image on the photosensitive drum 5A.

[0036] The photosensitive drum 5A, on which the toner image has been formed, transports the sheet S between itself and the transfer roller 7D. This transfers the toner image onto the sheet S. The heating roller 8A and the pressure roller 8B transport the sheet S on which the toner image has been transferred. This fixes the toner image onto the sheet S.

[0037] The sheet discharge unit 9 includes a transport roller 9A and an discharge roller 9B. The transport roller 9A transports the sheet S on which the toner image has been fixed toward the discharge roller 9B. The discharge roller 9B discharges the sheet S into the discharge tray 2B.

[0038] As shown in Figure 2, the scanning optical device 4 comprises a housing H, an incident optical system Li, a deflector 50, and a scanning optical system Lo. In the referenced drawings, the first, second, and third directions are indicated by arrows, with one direction indicated by an arrow and the other by no arrow.

[0039] The first direction is the direction in which the rotation axis X1 of the polygon mirror 51 of the deflector 50 extends. The second direction is perpendicular to the first direction. The third direction is perpendicular to both the first and second directions. In this embodiment, the second direction corresponds to the main scanning direction. In this embodiment, the third direction is the direction in which the four scanning lenses 70Y, 70M, 70C, and 70K are aligned (see Figure 4).

[0040] As shown in Figure 3, the housing H comprises a frame 100 and a cover 200. The cover 200 is detachable from the frame 100.

[0041] As shown in Figure 2, the frame 100 is to which the light source device LM, the deflector 50, and the scanning optical system Lo are mounted. The frame 100 has a frame base wall 110 and side walls 120. The frame base wall 110 forms part of the bottom of the frame 100. The deflector 50 is fixed to the frame base wall 110.

[0042] The side wall 120 extends from the frame base wall 110 in a first direction and constitutes the outer wall of the frame 100. The side wall 120 has a first side wall 121, a second side wall 122, a third side wall 123, and a fourth side wall 124. The first side wall 121, the second side wall 122, the third side wall 123, and the fourth side wall 124 each extend from the frame base wall 110 in one direction in the first direction.

[0043] The first side wall 121 is located at one end of the frame 100 in the second direction. The first side wall 121 connects one end of the third side wall 123 in the second direction and one end of the fourth side wall 124 in the second direction.

[0044] The second side wall 122 is located at the other end of the frame 100 in the second direction. The second side wall 122 is located on the opposite side of the polygon mirror 51 from the first side wall 121 in the second direction. The second side wall 122 connects the other end of the third side wall 123 in the second direction and the other end of the fourth side wall 124 in the second direction. The control board RR is located on the second side wall 122.

[0045] The third side wall 123 is located at one end of the frame 100 in the third direction (see also Figure 4). The third side wall 123 connects one end of the first side wall 121 in the third direction to one end of the second side wall 122 in the third direction.

[0046] The fourth side wall 124 is located at the other end of the frame 100 in the third direction. The fourth side wall 124 is located on the opposite side of the polygon mirror 51 from the third side wall 123 in the third direction. The fourth side wall 124 connects the other end of the first side wall 121 in the third direction and the other end of the second side wall 122 in the third direction.

[0047] As shown in Figure 4, the cover 200 is a wall that covers the deflector 50 from the opposite side of the frame base wall 110. The cover 200 covers the deflector 50 from one side in the first direction. The cover 200 is attached to the frame 100 and surrounds the deflector 50 between the frame 100 and the cover 200.

[0048] In this embodiment, the scanning optical device 4 is positioned within the main body housing 2 of the image forming apparatus 1 (see Figure 1) such that the frame base wall 110 is located above the deflector 50 and the cover 200 is located below the deflector 50. That is, in this embodiment, the first direction corresponds to the vertical direction of the image forming apparatus 1. More specifically, one side of the first direction corresponds to the lower side of the image forming apparatus 1, and the other side of the first direction corresponds to the upper side of the image forming apparatus 1.

[0049] As shown in Figure 2, the incident optical system Li comprises a light source device LM, an aperture wall 30, and a focusing lens 40. The light source device LM is an example of a light source.

[0050] The light source device LM is a device that emits beams BY, BM, BC, and BK. The light source device LM comprises semiconductor laser 10Y, semiconductor laser 10M, semiconductor laser 10C, semiconductor laser 10K, coupling lens 20Y, coupling lens 20M, coupling lens 20C, coupling lens 20K, and control board RR.

[0051] The semiconductor laser 10Y emits laser light to expose the yellow photosensitive drum 5AY. The semiconductor laser 10M emits laser light to expose the magenta photosensitive drum 5AM. The semiconductor laser 10C emits laser light to expose the cyan photosensitive drum 5AC. The semiconductor laser 10K emits laser light to expose the black photosensitive drum 5AK.

[0052] The coupling lens 20Y converts the light emitted from the semiconductor laser 10Y into beam BY. The coupling lens 20M converts the light emitted from the semiconductor laser 10M into beam BM. The coupling lens 20C converts the light emitted from the semiconductor laser 10C into beam BC. The 20K coupling lens converts the light emitted from the 10K semiconductor laser into a BK beam.

[0053] The control board RR is a substrate for controlling the semiconductor lasers 10Y, 10M, 10C, and 10K. The control board RR has a plate shape. In addition to the semiconductor lasers 10Y, 10M, 10C, and 10K, the control unit and connectors are fixed to the control board RR (not shown).

[0054] As shown in Figure 3, the focusing lens 40 is a lens that refracts the beams BY, BM, BC, and BK from the coupling lens 20 in the sub-scanning direction and focuses them onto the mirror surface of the polygon mirror 51. In the incident optical system Li, the sub-scanning direction corresponds to the first direction.

[0055] In this embodiment, the focusing lens 40 is a cylindrical lens with a cylindrical incident surface and a flat exit surface. The focusing lens 40 refracts beams BY and BK so that they approach the frame base wall 110 in the first direction and focuses them onto the mirror surface of the polygon mirror 51. The focusing lens 40 also refracts beams BM and BC so that they approach the cover 200 in the first direction and focuses them onto the mirror surface of the polygon mirror 51.

[0056] The diaphragm wall 30 includes a first diaphragm wall 30A and a second diaphragm wall 30B. In this embodiment, the first diaphragm wall 30A and the second diaphragm wall 30B are integrally formed with the frame 100. That is, the frame 100 has the first diaphragm wall 30A and the second diaphragm wall 30B.

[0057] The first aperture wall 30A is a wall located between the coupling lenses 20Y, 20M, 20C, 20K and the focusing lens 40. The first aperture wall 30A has an aperture 31 (see Figure 2). The aperture 31 includes an aperture 31Y through which the beam BY from the coupling lens 20Y toward the polygon mirror 51 passes, an aperture 31M through which the beam BM from the coupling lens 20M toward the polygon mirror 51 passes, an aperture 31C through which the beam BC from the coupling lens 20C toward the polygon mirror 51 passes, and an aperture 31K through which the beam BK from the coupling lens 20K toward the polygon mirror 51 passes.

[0058] The second aperture wall 30B is a wall located between the condensing lens 40 and the deflector 50. The condensing lens 40 is located between the first aperture wall 30A and the second aperture wall 30B. The second aperture wall 30B has two apertures 32A and 32B. Aperture 32A is the aperture through which beams BY and BM, which are directed from coupling lenses 20Y and 20M toward the polygon mirror 51, pass. Aperture 32B is the aperture through which beams BC and BK, which are directed from coupling lenses 20C and 20K toward the polygon mirror 51, pass.

[0059] The deflector 50 is a device that deflects the beams BY, BM, BC, and BK in the main scanning direction (second direction). The deflector 50 includes a polygon mirror 51, a motor 52, a circuit board 53, a first capacitor 54, and a second capacitor 55.

[0060] The polygon mirror 51 is rotatable around a rotation axis X1 extending in the first direction. The polygon mirror 51 has five mirror surfaces equidistant from the rotation axis X1 (see also Figure 2). By rotating, the polygon mirror 51 deflects the beams BY, BM, BC, and BK in the main scanning direction.

[0061] Motor 52 is a motor that rotates the polygon mirror 51. Motor 52 is fixed to the frame 100 via a circuit board 53. The first capacitor 54 and the second capacitor 55 are cylindrical electronic components that form part of the drive circuit of the motor 52.

[0062] The circuit board 53 is equipped with a motor 52, a first capacitor 54, and a second capacitor 55. The motor 52, the first capacitor 54, and the second capacitor 55 are mounted on the circuit board 53 so as to protrude toward the cover 200.

[0063] As shown in Figure 4, the scanning optical system Lo is an optical system that images the beams BY, BM, BC, and BK, which have been deflected by the deflector 50, onto the surface of the photosensitive drum 5A.

[0064] The scanning optical system Lo images the beam BY, which has been deflected by the deflector 50, onto the surface of the photosensitive drum 5AY. The scanning optical system Lo images the beam BM, which has been deflected by the deflector 50, onto the surface of the photosensitive drum 5AM. The scanning optical system Lo images the beam BC, which has been deflected by the deflector 50, onto the surface of the photosensitive drum 5AC. The scanning optical system Lo images the beam BK, which has been deflected by the deflector 50, onto the surface of the photosensitive drum 5AK.

[0065] The scanning optical system Lo includes scanning lenses 60YM, 60CK, 70Y, 70M, 70C, and 70K, a first mirror 81Y, a second mirror 81M, a fifth mirror 82M, a third mirror 81C, a sixth mirror 82C, and a fourth mirror 81K. Each component constituting the scanning optical system Lo is fixed to the frame 100. The first mirror 81Y, the second mirror 81M, the third mirror 81C, and the fourth mirror 81K are examples of mirrors.

[0066] Scanning lenses 70Y, 70M, 70C, and 70K are the lenses closest to the photosensitive drums 5AY, 5AM, 5AC, and 5AK, respectively, in the scanning optical system Lo.

[0067] The first mirror 81Y, the second mirror 81M, the third mirror 81C, and the fourth mirror 81K are positioned upstream of the scanning lenses 70Y, 70M, 70C, and 70K. During the assembly process of the scanning optical device 4, the angles of the first mirror 81Y, the second mirror 81M, the third mirror 81C, and the fourth mirror 81K need to be adjusted around the main scanning direction. During the assembly process, the incident position of the beam on the scanning lenses 70Y, 70M, 70C, and 70K is adjusted by adjusting the angles of the first mirror 81Y, the second mirror 81M, the third mirror 81C, and the fourth mirror 81K.

[0068] Scanning lens 60YM is the lens to which beams BY and BM, deflected by the deflector 50, are incident. Scanning lens 60CK is the lens to which beams BC and BK, deflected by the deflector 50, are incident. Scanning lenses 60YM and 60CK refract the beams BY, BM, BC, and BK, deflected by the deflector 50, in the main scanning direction to form an image on the surface of the photosensitive drum 5A. Furthermore, scanning lenses 60YM and 60CK have an fθ characteristic such that the beams BY, BM, BC, and BK, deflected at a constant angular velocity by the deflector 50, are scanned at a constant velocity on the surface of the photosensitive drum 5A. Scanning lenses 60YM and 60CK are arranged symmetrically with respect to a plane perpendicular to a third direction passing through the rotation axis X1 of the polygon mirror 51.

[0069] The first mirror 81Y is a mirror that reflects the beam BY that has passed through the scanning lens 60YM toward the surface of the photosensitive drum 5AY. The scanning lens 70Y is a lens that images the beam BY reflected by the first mirror 81Y onto the surface of the photosensitive drum 5AY. The scanning lenses 70Y, 70M, 70C, and 70K refract the beams BY, BM, BC, and BK in the sub-scanning direction to image them onto the surface of the photosensitive drum 5A. In the scanning optical system Lo, the sub-scanning direction corresponds to a direction perpendicular to both the main scanning direction and the beam propagation direction.

[0070] The fifth mirror 82M is a mirror that reflects the beam BM that has passed through the scanning lens 60YM toward the second mirror 81M. The second mirror 81M is a mirror that reflects the beam BM toward the surface of the photosensitive drum 5AM. The scanning lens 70M is a lens that images the beam BM reflected by the second mirror 81M onto the surface of the photosensitive drum 5AM.

[0071] The sixth mirror 82C is a mirror that reflects the beam BC that has passed through the scanning lens 60CK toward the third mirror 81C. The third mirror 81C is a mirror that reflects the beam BC toward the surface of the photosensitive drum 5AC. The scanning lens 70C is a lens that images the beam BC reflected by the third mirror 81C onto the surface of the photosensitive drum 5AC.

[0072] The fourth mirror 81K is a mirror that reflects the beam BK that has passed through the scanning lens 60CK toward the surface of the photosensitive drum 5AK. The scanning lens 70K is a lens that images the beam BK reflected by the fourth mirror 81K onto the surface of the photosensitive drum 5AK.

[0073] As shown in Figure 3, the light emitted from each semiconductor laser 10Y, 10M, 10C, and 10K is converted into beams BY, BM, BC, and BK by passing through the corresponding coupling lenses 20Y, 20M, 20C, and 20K. The beams BY, BM, BC, and BK then pass through the corresponding apertures 31Y, 31M, 31C, and 31K of the first aperture wall 30A and are then incident on the focusing lens 40. After passing through the focusing lens 40, the beams BY, BM, BC, and BK pass through the corresponding apertures 32A and 32B of the second aperture wall 30B and are then incident on the polygon mirror 51.

[0074] As shown in Figure 4, the polygon mirror 51 deflects the beams BY, BM, BC, and BK toward the corresponding scanning optical system Lo.

[0075] After passing through scanning lens 60YM, beam BY is reflected by the first mirror 81Y, passes through scanning lens 70Y, and is emitted toward the photosensitive drum 5AY. Beam BY is imaged on the surface of the photosensitive drum 5AY and scanned in the main scanning direction.

[0076] After passing through scanning lens 60YM, beam BM is reflected by the fifth mirror 82M and the second mirror 81M, passes through scanning lens 70M, and is emitted toward the photosensitive drum 5AM. Beam BM is imaged on the surface of the photosensitive drum 5AM and scanned in the main scanning direction.

[0077] After passing through the scanning lens 60CK, the beam BC is reflected by the sixth mirror 82C and the third mirror 81C, passes through the scanning lens 70C, and is emitted toward the photosensitive drum 5AC. The beam BC is imaged on the surface of the photosensitive drum 5AC and scanned in the main scanning direction.

[0078] After passing through scanning lens 60CK, beam BK is reflected by the fourth mirror 81K, passes through scanning lens 70K, and is emitted toward the photosensitive drum 5AK. Beam BK is imaged on the surface of the photosensitive drum 5AK and scanned in the main scanning direction.

[0079] Here, as shown in Figure 2, the first mirror 81Y, the second mirror 81M, the third mirror 81C, and the fourth mirror 81K are attached to the frame 100 from the opposite side of the cover 200. The first mirror 81Y, the second mirror 81M, the third mirror 81C, and the fourth mirror 81K are fixed to the frame 100 by being biased at both ends by springs SP.

[0080] As shown in Figure 5, the frame 100 has a first mounting portion 131 to which the first mirror 81Y is attached, a second mounting portion 132 to which the second mirror 81M is attached, a third mounting portion 133 to which the third mirror 81C is attached, and a fourth mounting portion 134 to which the fourth mirror 81K is attached.

[0081] The first mounting portion 131 has a first contact portion 131A, a first adhesive portion 131B, a second contact portion 131C, and a first guide surface 131D. The second mounting portion 132 has a third contact portion 132A, a second adhesive portion 132B, a fourth contact portion 132C, and a second guide surface 132D. The third mounting portion 133 includes a fifth contact portion 133A, a third adhesive portion 133B, a sixth contact portion 133C, and a third guide surface 133D. The fourth mounting portion 134 has a seventh contact portion 134A, a fourth adhesive portion 134B, an eighth contact portion 134C, and a fourth guide surface 134D. Note that the configurations of the second mounting section 132, the third mounting section 133, and the fourth mounting section 134 are the same as those of the first mounting section 131; therefore, the configuration of the first mounting section 131 will be explained, and the explanations of the other mounting sections will be omitted. The first guide surface 131D, the second guide surface 132D, the third guide surface 133D, and the fourth guide surface 134D are examples of guide surfaces.

[0082] Furthermore, in the following description, the longitudinal direction of the first mirror 81Y is referred to as the "longitudinal direction," the short direction of the first mirror 81Y is referred to as the "short direction," and the thickness direction of the first mirror 81Y is referred to as the "thickness direction." In this embodiment, the longitudinal direction is the direction along the main scanning direction.

[0083] As shown in Figure 6, the first mirror 81Y has a first surface F1 having a reflective surface and a second surface F2 facing the shorter direction. The first surface F1 extends in the longitudinal and shorter directions. The first surface F1 extends in the longitudinal and thickness directions.

[0084] Frame 100 comprises a main frame 100M and a subframe 100S. The subframe 100S is separable from the main frame 100M. In this embodiment, two subframes 100S are arranged corresponding to each mounting section 131-134, and are attached to the ends of the longitudinal direction of each mirror 81Y, 81M, 81C, and 81K. The subframe 100S is a smaller component compared to the main frame 100M.

[0085] The first contact portion 131A is positioned on the subframe 100S. The first contact portion 131A contacts the first surface F1. By contacting the first surface F1, the first contact portion 131A positions the first mirror 81Y in the thickness direction. As shown in Figure 8(a), the first contact portion 131A has an arc-shaped surface when viewed along its longitudinal direction. That is, only the vertex of the arc shape of the first contact portion 131A contacts the first surface F1 of the first mirror 81Y. The vertex of the first contact portion 131A protrudes toward the first mirror 81Y and can act as a pivot point when adjusting the orientation of the first mirror 81Y by contacting the first mirror 81Y.

[0086] The first adhesive portion 131B is located on the subframe 100S. There are two first adhesive portions 131B located on either side of the first contact portion 131A. The first adhesive portions 131B are aligned with the first contact portion 131A in the shorter direction. Photocurable resin LR is placed in the first adhesive portion 131B. As shown in Figure 8(b), when the first mirror 81Y is attached to the frame 100, the photocurable resin LR is fixed to the first adhesive portion 131B.

[0087] The photocurable resin LR is a resin that hardens when exposed to light, such as an ultraviolet-curable resin. The photocurable resin LR is arranged in the short direction alongside the first contact portion 131A. The photocurable resin LR is positioned between the first mirror 81Y and the frame 100.

[0088] As shown in FIG. 7, the second contact portion 131C is disposed on the main frame 100M. The second contact portion 131C is disposed corresponding to each of one end and the other end in the longitudinal direction of the first mirror 81Y. The second contact portion 131C contacts the second surface F2 of the first mirror 81Y. By contacting the second surface F2, the second contact portion 131C positions the first mirror 81Y in the short-side direction. As shown in FIG. 8(a), in the thickness direction, the dimension D3 of the second contact portion 131C is smaller than the thickness D2 of the first mirror 81Y (D3<D2). As shown in FIG. 8(b), an inclined surface 131E extending from the upper end of the second contact portion 131C is formed at the upper end of the second contact portion 131C. The inclined surface 131E is a surface inclined with respect to the second contact portion 131C and extends in a direction away from the first mirror 81Y.

[0089] As shown in FIG. 7, the first guide surface 131D is disposed on the main frame 100M. A plurality of first guide surfaces 131D are arranged. In the present embodiment, three first guide surfaces 131D are arranged side by side in the longitudinal direction. In the longitudinal direction, each first guide surface 131D is located between two second contact portions 131C. In the short-side direction, each first guide surface 131D is farther from the second surface F2 than the second contact portion 131C. That is, in a state where the first mirror 81Y is attached to the frame 100, each first guide surface 131D does not contact the first mirror 81Y.

[0090] As shown in FIG. 8(a), the first guide surface 131D extends in the thickness direction of the first mirror 81Y. The first guide surface 131D extends from the attachment position of the first mirror 81Y toward the outside of the frame 100. In the thickness direction, the dimension D1 of the first guide surface 131D is larger than the thickness D2 of the first mirror 81Y (D1>D2).

[0091] As shown in FIG. 6, the springs SP are disposed one by one at both ends in the longitudinal direction of the first mirror 81Y. The spring SP is a leaf spring having a U shape. The spring SP has a locking portion SPJ and an opening SPK.

[0092] The locking portion SPJ is a hole that engages with the projection 100T of the frame 100. When the locking portion SPJ engages with the projection 100T, the spring SP engages with the frame 100. When the spring SP engages with the frame 100, the spring SP biases the first mirror 81Y toward the first contact portion 131A of the frame 100.

[0093] As shown in Figure 7, when the first mirror 81Y is attached to the frame 100, the opening SPK is positioned to overlap with the first adhesive portion 131B when viewed along the thickness direction. That is, the opening SPK is positioned to overlap with the photocurable resin LR when viewed along the thickness direction. Furthermore, the first mirror 81Y does not have a reflective film that constitutes a reflective surface at both ends in the longitudinal direction (not shown). This allows light transmitted through the aperture SPK to reach the photocurable resin LR.

[0094] Next, referring to Figures 9(a), (b), and (c), the procedure for attaching the first mirror 81Y to the frame 100 will be described. Since the attachment methods for the second mirror 81M, the third mirror 81C, and the fourth mirror 81K are the same as those for the first mirror 81Y, the attachment method for the first mirror 81Y will be explained, and the attachment methods for the other mirrors 81M, 81C, and 81K will be omitted. As shown in Figure 9(a), when attaching the first mirror 81Y to the frame 100, first, the photocurable resin LR is applied to the first adhesive portion 131B. Next, the second surface F2 of the first mirror 81Y is brought into contact with the first guide surface 131D, and the first mirror 81Y is moved to the mounting position along the first guide surface 131D.

[0095] As the first mirror 81Y is moved from the position shown in Figure 9(a) to the position shown in Figure 9(b), the second surface F2 comes into contact with the inclined surface 131E. When the second surface F2 comes into contact with the inclined surface 131E, the first mirror 81Y is lifted by the inclined surface 131E, and the second surface F2 is guided to the second contact portion 131C.

[0096] As the second surface F2 contacts the second contact portion 131C and the first mirror 81Y is moved further along the second surface F2, the first surface F1 of the first mirror 81Y comes into contact with the first contact portion 131A, as shown in Figure 9(b).

[0097] When the first surface F1 of the first mirror 81Y comes into contact with the first contact portion 131A, and the second surface F2 of the first mirror 81Y comes into contact with the second contact portion 131C, the second surface F2 separates from the first guide surface 131D.

[0098] When the first surface F1 of the first mirror 81Y comes into contact with the first contact portion 131A, the first surface F1 comes into contact with the photocurable resin LR and presses the photocurable resin LR toward the first contact portion 131A, causing the photocurable resin LR to spread between the first surface F1 and the first adhesive portion 131B. At this time, as the first mirror 81Y slides along the first guide surface 131D, the first surface F1 moves precisely in the thickness direction, so that the photocurable resin LR spreads while being held between the first surface F1 and the first adhesive portion 131B.

[0099] Next, as shown in Figure 9(c), the spring SP is attached to the frame 100. Once the spring SP is attached to the frame 100, the spring SP presses the first mirror 81Y toward the frame 100.

[0100] Next, with light emitted from the semiconductor laser 10, the angle of the first mirror 81Y is adjusted by tilting it starting from the first contact portion 131A while monitoring the position of the beam on the image plane. When adjusting the angle of the first mirror 81Y, the arm AM, shown by the dashed line, is pressed against the first mirror 81Y to move it. After the angle adjustment is complete, the first mirror 81Y is fixed to the frame 100 by shining light on the photocurable resin LR. Furthermore, after positioning, the fixed first mirror 81Y may or may not be in contact with the second contact portion 131C.

[0101] Based on the above, the following effects can be obtained in this embodiment. When assembling the first mirror 81Y to the frame 100, it is difficult to move the first mirror 81Y to the mounting position on the frame 100. However, in the scanning optical device 4 of this embodiment, the multiple first guide surfaces 131D are further away from the second surface F2 than the second contact portion 131C in the short direction and extend in the thickness direction of the first mirror 81Y. Therefore, when assembling the scanning optical device 4, the multiple first guide surfaces 131D can easily guide the first mirror 81Y to the mounting position on the frame 100 when attaching the first mirror 81Y to the frame 100.

[0102] As shown in Figures 9(a) and 9(b), if the first guide surface 131D is absent, when the first mirror 81Y is brought closer to the first mounting portion 131, the first mirror 81Y is likely to shift from its predetermined position. As a result, the photocurable resin LR cannot be pressed along the thickness direction, and the photocurable resin LR may spread to unintended locations. However, since the second surface F2 of the first mirror 81Y is guided by the first guide surface 131D, the photocurable resin LR can be pressed in the thickness direction, thus preventing the photocurable resin LR from spreading to unintended locations.

[0103] Furthermore, since multiple first guide surfaces 131D are located between the two second contact portions 131C, it is easy to bring the first mirror 81Y into contact with the first guide surfaces 131D, and easy to guide the first mirror 81Y to the mounting position.

[0104] Furthermore, because the first contact portion 131A has an arc-shaped surface, the angle of the first mirror 81Y can be easily adjusted.

[0105] Furthermore, since the scanning optical device includes a photocurable resin LR between the first mirror 81Y and the frame 100, the angle of the first mirror 81Y can be adjusted and then fixed.

[0106] Furthermore, the scanning optical device has a spring SP that engages with the frame 100 and biases the first mirror 81Y toward the first contact portion 131A. Therefore, the first mirror 81Y can be temporarily fixed to the frame 100. In addition, since the spring SP has an opening SPK at a position that overlaps with the photocurable resin LR, the photocurable resin LR can be cured by shining light on it through the opening SPK.

[0107] Furthermore, the frame 100 comprises a main frame 100M and a subframe 100S having a first contact portion 131A. Therefore, by removing the subframe 100S from the main frame 100M, the first mirror 81Y can be easily removed from the main frame 100M. For example, even after the first mirror 81Y has been fixed to the frame 100 with light-curing resin LR, the fixing work of the first mirror 81Y can be redone by replacing the subframe 100S without having to replace the main frame 100M. Since the subframe 100S is a smaller part compared to the main frame 100M, the cost of redoing the fixing work can be reduced.

[0108] Furthermore, the dimension D1 of the first guide surface 131D is greater than the thickness D2 of the first mirror 81Y (D1 > D2). Therefore, when installing the first mirror 81Y, it can be guided over a long section. This allows the first mirror 81Y to be guided over a long section, making the assembly process easier.

[0109] Although embodiments have been described above, the scanning optical apparatus and the image forming apparatus can be modified as appropriate, as illustrated below.

[0110] In the above embodiment, three first guide surfaces 131D that guide the mounting of the first mirror 81Y were arranged in a row in the longitudinal direction, but there may be two or more first guide surfaces.

[0111] In the above embodiment, the image forming apparatus 1 was a printer, but for example, the image forming apparatus may be a copier, a multifunction printer, or the like.

[0112] In the above embodiment, the scanning optical device 4 was a scanning optical device used in the image forming apparatus 1, but for example, the scanning optical device may be a scanning optical device used in an apparatus other than an image forming apparatus.

[0113] The elements described in the above embodiments and modifications may be implemented in any combination. [Explanation of Symbols]

[0114] 81Y 1st Mirror 100 frames 131A 1st contact part 131B 1st adhesive part 131C 2nd contact part 131D First guide surface F1 front page F2 2nd side

Claims

1. A scanning optical device used in an image forming apparatus, A light source comprising a semiconductor laser and a coupling lens that converts light emitted from the semiconductor laser into a beam, A deflector having a polygon mirror that deflects the beam emitted from the light source in the main scanning direction, A scanning optical system having a mirror that reflects the beam deflected by the polygon mirror, and that images the beam deflected by the deflector onto the scanning surface, The system comprises a frame on which the light source, the deflector, and the scanning optical system are mounted, The aforementioned mirror is It has a first surface having a reflective surface extending in the longitudinal direction and in the short direction perpendicular to the longitudinal direction, and a second surface facing the short direction, The aforementioned frame is A first contact portion that contacts the first surface, A second contact portion that contacts the second surface, A scanning optical apparatus characterized by having a plurality of guide surfaces that are further from the second surface than the second contact portion in the short direction, and which extend in the thickness direction of the mirror.

2. The second contact portion is positioned corresponding to one end and the other end of the mirror in the longitudinal direction, The scanning optical apparatus according to claim 1, characterized in that, in the longitudinal direction, the plurality of guide surfaces are located between the two second contact portions.

3. The scanning optical apparatus according to claim 1, characterized in that the first contact portion has an arc-shaped surface when viewed along the longitudinal direction.

4. The scanning optical apparatus according to claim 1, further comprising a photocurable resin arranged in the short direction alongside the first contact portion, the photocurable resin being arranged between the mirror and the frame.

5. The frame has a spring that engages with the mirror and biases the mirror toward the first contact portion, The scanning optical apparatus according to claim 4, characterized in that the spring has an opening at a position that overlaps with the photocurable resin when viewed along the thickness direction of the mirror.

6. The aforementioned frame is Mainframe and The scanning optical apparatus according to claim 5, comprising a subframe separable from the mainframe, the subframe having an adhesive portion to which the photocurable resin is fixed and the first contact portion.

7. The scanning optical apparatus according to claim 1, characterized in that, in the thickness direction, the dimensions of the guide surface are greater than the thickness of the mirror.

8. The scanning optical apparatus according to claim 1, characterized in that, in the thickness direction, the dimensions of the second contact portion are smaller than the thickness of the mirror.

Images