Optical apparatus, scanning optical apparatus, and image forming apparatus

Abstract

To suppress the lifting of the optical element from the second and third support parts. [Solution] A first support portion located at one end of the optical element in the longitudinal direction supports the first or second surface of the optical element; a second support portion located at the other end in the longitudinal direction supports the portion of the first surface of the optical element at one end in the short direction; and a third support portion located at the other end in the longitudinal direction supports the portion of the first or second surface of the optical element at the other end in the short direction. The pressing force of the pressing portion that presses the optical element toward the second and third support portions is set to be greater than the pressing force of the first pressing member that presses the optical element toward the first support portion.

Description

Technical Field

[0001] The present invention relates to an optical device, a scanning optical device, and an image forming device.

Background Art

[0002] In an electrophotographic image forming apparatus, an electrostatic latent image is formed on an image carrier such as a photoreceptor drum by a scanning optical device, and this electrostatic latent image is developed by a developing device to form a toner image. The scanning optical device forms an electrostatic latent image on the image carrier by deflecting the scanning light emitted from a light source with an optical polarizer. In an optical scanning device, optical elements such as mirrors and lenses are arranged on the optical path of the scanning light. Various developments have also been made on optical devices provided with optical elements.

[0003] In order to facilitate adjustment of the posture of the optical element and suppress distortion of the optical element, in an optical device, one end side in the longitudinal direction of the optical element may be supported at one point (one location) and the other end side may be supported at two points (two locations) (see Patent Document 1, etc.). Briefly explaining the optical device described in Patent Document 1, it is as follows.

[0004] On one end side in the longitudinal direction of the optical element, a first support portion (referred to as a pin in Patent Document 1) that supports a portion on the central side in the short-side direction of the optical element on one side surface in the thickness direction of the optical element is arranged. On the other end side in the longitudinal direction of the optical element, a second support portion (referred to as a pin in Patent Document 1) that supports a portion on the one end side in the short-side direction of the optical element on one side surface in the thickness direction of the optical element is arranged. On the other end side in the longitudinal direction of the optical element, a third support portion (referred to as a pin in Patent Document 1) that supports a portion on the other end side in the short-side direction of the optical element on one side surface in the thickness direction of the optical element is arranged.

[0005] In the optical device described in Patent Document 1, one end side in the longitudinal direction of the optical element is pressed toward the first support portion side by a first pressing member such as a leaf spring. The other end side in the longitudinal direction of the optical element is pressed toward the second support portion side and the third support portion side by a second pressing member such as a leaf spring. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2011-100022 [Overview of the project] [Problems that the invention aims to solve]

[0007] Incidentally, in the optical apparatus described in Patent Document 1, the pressing point of the first pressing member may shift from the point opposite to the support point of the first support due to processing errors, etc., causing a rotational moment that results in the optical element lifting off the second or third support. As a result, the optical element may rotate and vibrate around its axis along its longitudinal direction, which may lead to deterioration of the image quality of the image forming apparatus, such as uneven image density.

[0008] Therefore, the present invention aims to provide an optical device, etc., that can suppress the lifting of the optical element from the second support portion and the third support portion when one end of the optical element in the longitudinal direction is supported at one point and the other end is supported at two points. [Means for solving the problem]

[0009] One aspect of the optical device according to the present invention is: An optical element having a first surface and a second surface on both sides in the thickness direction, A first support portion is provided, which is positioned on one end of the optical element in the longitudinal direction and supports the first or second surface, A first pressing member presses the optical element toward the first support portion, A second support portion is positioned on the other end in the longitudinal direction and supports the portion of the optical element on the first surface on one end in the short direction, A third support portion is positioned on the other end in the longitudinal direction and supports the portion on the other end in the short direction of the first or second surface, The optical element is provided with a pressing portion that presses the optical element toward the second support portion and the third support portion, The pressing force of the pressing portion is set to be greater than the pressing force of the first pressing member.

[0010] One aspect of the scanning optical apparatus according to the present invention is: A light source that emits scanning light, A polarizer that polarizes the scanning light emitted from the aforementioned light source, The system comprises the optical device described above, which is arranged on the optical path of the scanning light polarized by the polarizer.

[0011] One aspect of the image forming apparatus according to the present invention is: An image carrier for forming an image, The system comprises the scanning optical device described above, which exposes and scans the image carrier to form an electrostatic latent image on the image carrier. [Effects of the Invention]

[0012] According to the present invention, when one end of an optical element is supported at one point in the longitudinal direction and the other end is supported at two points, it is possible to suppress the lifting of the optical element from the second support portion and the third support portion. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a schematic front view of the image forming apparatus according to this embodiment. [Figure 2] Figure 2 is a schematic cross-sectional view of the scanning optical apparatus according to this embodiment. [Figure 3] Figure 3 is a schematic side cross-sectional view of the scanning optical apparatus according to this embodiment. [Figure 4] Figure 4 is a schematic left side view of the optical device according to the first embodiment. [Figure 5] Figure 5 is a schematic right side view of the optical device according to the first embodiment. [Figure 6] Figure 6 is an enlarged view along the line VI-VI in Figure 4. [Figure 7]FIG. 7 is an enlarged view taken along line VII-VII in FIG. 4. [Figure 8] FIG. 8 is a schematic cross-sectional view of one end side in the longitudinal direction of an optical element in an optical device according to another aspect of the first embodiment. [Figure 9] FIG. 9 is a conceptual diagram of one end side in the longitudinal direction of an optical element in an optical device according to the first embodiment. [Figure 10] FIG. 10 is a conceptual diagram of the other end side in the longitudinal direction of an optical element in an optical device according to the first embodiment. [Figure 11] FIG. 11 is a conceptual diagram of the other end side in the longitudinal direction of an optical element in an optical device according to another aspect of the first embodiment. [Figure 12] FIG. 12 is a conceptual diagram along the longitudinal direction of an optical element in an optical device according to another aspect of the first embodiment. [Figure 13] FIG. 13 is a conceptual diagram of one end side in the longitudinal direction of an optical element in an optical device according to the second embodiment. [Figure 14] FIG. 14 is a conceptual diagram of the other end side in the longitudinal direction of an optical element in an optical device according to the second embodiment. [Figure 15] FIG. 15 is a conceptual diagram of the other end side in the longitudinal direction of an optical element in an optical device according to a modified example of the second embodiment. [Figure 16] FIG. 16 is a conceptual diagram along the longitudinal direction of an optical element in an optical device according to a modified example of the second embodiment.

Embodiments for Carrying out the Invention

[0014] Hereinafter, this embodiment will be described with reference to the drawings. In the specification and claims of this application, "upstream" refers to the upstream side in the paper transport direction, and "downstream" refers to the downstream side in the paper transport direction. In the drawings, "front" refers to the forward direction, "back" refers to the rear direction, "left" refers to the left direction, "right" refers to the right direction, "up" refers to the up direction, and "down" refers to the down direction. "LD" refers to the longitudinal direction of the optical element, "LDa" refers to one end of the longitudinal direction of the optical element, and "LDb" refers to the other end of the longitudinal direction of the optical element. "SD" refers to the short direction of the optical element, "SDa" refers to one end of the short direction of the optical element, and "SDb" refers to the other end of the short direction of the optical element. "TD" refers to the thickness direction of the optical element, "TDa" refers to one side of the thickness direction of the optical element, and "TDb" refers to the other side of the thickness direction of the optical element.

[0015] Referring to Figure 1, the overall configuration of the image forming apparatus 10 according to this embodiment will be described. Figure 1 is a schematic front view of the image forming apparatus 10 according to this embodiment.

[0016] As shown in Figure 1, the image forming apparatus 10 according to this embodiment is an apparatus that forms a toner image on paper S, which is a recording medium, using an electrophotographic method. The image forming apparatus 10 includes a box-shaped apparatus body 12, which constitutes the base frame of the image forming apparatus 10.

[0017] An image reading unit 14 for reading images from a document is provided at the top of the main body 12 of the device. The image reading unit 14 optically scans the document D placed on the contact glass, or the document D being transported on the contact glass. The image reading unit 14 optically reads the scanned image of the document using a CCD (Charge Coupled Device) sensor 16 and generates image data. In addition, an image processing unit 18 is provided at the top of the main body 12 for performing image processing such as shading correction and compression on the image data from the image reading unit 14.

[0018] Above the image reading unit 14 in the main body 12 of the device, there is a document transport unit 20 called an ADF (Auto Document Feeder). The document transport unit 20 transports the document D set in the document tray onto the contact glass of the image reading unit 14. Also, on the front side of the upper part of the main body 12, there is an operation display unit 22 that functions as both an operation unit and a display unit. The operation display unit 22 is composed of, for example, a liquid crystal display (LCD) with a touchscreen. The operation display unit 22 has various operation keys such as a numeric keypad and a start key, and as an operation unit, it accepts various input operations from the user. As a display unit, the operation display unit 22 displays various operation screens, the status of images, and the operating status of each function.

[0019] As shown in Figure 1, an image forming unit 24 is provided in the upper part of the main body 12 of the device, which forms images by electrophotography. The image forming unit 24 has four image forming units 26Y, 26M, 26C, and 26K for forming images using colored toners of Y (yellow), M (magenta), C (cyan), and K (black) components based on image data. The four image forming units 26Y, 26M, 26C, and 26K are arranged along the vertical direction.

[0020] The image forming units 26Y, 26M, 26C, and 26K for the Y, M, C, and K components have similar configurations. For the sake of illustration and explanation, common components are indicated by the same reference numeral, and when distinguishing them, Y, M, C, or K is added to the reference numeral. In Figure 1, only the components of the image forming unit 26Y for the Y component are given reference numerals, while the components of the other image forming units 26M, 26C, and 26K are omitted.

[0021] The image forming unit 26 includes a photosensitive drum 28, a charging unit 30, a scanning optical device (exposure unit) 32, a developing unit 34, and a drum cleaning unit 36 ​​arranged around it.

[0022] The photoreceptor drum 28 is an image carrier for forming an image. The photoreceptor drum 28 is a negatively charged organic photoreceptor, for example, made of aluminum, with an undercoat layer, a charge generation layer, and a charge transport layer sequentially laminated on the circumferential surface of a conductive cylindrical body. The photoreceptor drum 28 rotates at a constant peripheral speed driven by a rotary motor (not shown).

[0023] The charging unit 30 uniformly charges the outer surface of the photoreceptor drum 28 with negative polarity. The scanning optical device 32 emits laser light as scanning light and scans the outer surface of the photoreceptor drum 28, which acts as an image carrier, thereby forming an electrostatic latent image on the outer surface of the photoreceptor drum 28. The amount of light emitted from the scanning optical device 32 is modulated according to the image data of each YMCK color.

[0024] The developing unit 34 is, for example, a developing unit using a two-component developing method. The developing unit 34 forms a toner image by making an electrostatic latent image visible on the outer surface of the photoreceptor drum 28 by depositing toner of each color component onto the outer surface of the photoreceptor drum 28. The drum cleaning unit 36 ​​cleans the remaining toner that remains on the outer surface of the photoreceptor drum 28 after the primary transfer. The drum cleaning unit 36 ​​has a drum cleaning blade or the like that slides against the outer surface of the photoreceptor drum 28.

[0025] As shown in Figure 1, a transfer unit 38 for transferring a toner image onto paper S is provided in the upper part of the main body 12 of the device. The transfer unit 38 includes an endless intermediate transfer belt 40, a plurality of support rollers 42, a primary transfer roller 44, a secondary transfer roller 46, and a belt cleaning unit 48.

[0026] The intermediate transfer belt 40 extends in the vertical direction and is stretched over a plurality of support rollers 42. The intermediate transfer belt 40 circulates through the rotation of the plurality of support rollers 42. At least one of the plurality of support rollers 42 is a drive roller connected to a rotary motor (not shown), and the other support rollers 42 are driven rollers (free rollers).

[0027] The primary transfer roller 44 is positioned on the inner circumferential surface side of the intermediate transfer belt 40, facing the photoreceptor drums 28 for each color component. The primary transfer roller 44 works in cooperation with the photoreceptor drums 28 to grip the intermediate transfer belt 40. A primary transfer nip CN is formed between the outer circumferential surface of the primary transfer roller 44 and the outer circumferential surface of the photoreceptor drums 28 to transfer the toner image from the photoreceptor drums 28 to the intermediate transfer belt 40.

[0028] The secondary transfer roller 46 is positioned on the outer circumferential side of the intermediate transfer belt 40, facing a predetermined support roller 42. The secondary transfer roller 46 works in cooperation with the predetermined support roller 42 to grip the intermediate transfer belt 40. A secondary transfer nip TN is formed between the outer circumferential surface of the secondary transfer roller 46 and the outer circumferential surface of the predetermined support roller 42 for transferring the toner image from the intermediate transfer belt 40 to the paper S.

[0029] As the intermediate transfer belt 40 passes through the primary transfer nip CN, the toner image of the photoreceptor drum 28 is sequentially superimposed onto the intermediate transfer belt 40 and primary transferred. Specifically, a primary transfer bias is applied to the primary transfer roller 44, and a charge with the opposite polarity to the toner is applied to the back side of the intermediate transfer belt 40 (the side that contacts the primary transfer roller 44), thereby electrostatically transferring the toner image to the intermediate transfer belt 40.

[0030] Subsequently, as the paper S passes through the secondary transfer nip TN, the toner image on the intermediate transfer belt 40 is secondary transferred to the paper S. Specifically, by applying a secondary transfer bias of the same polarity as the toner to a predetermined support roller 42 and applying a charge of the same polarity as the toner to the back side of the intermediate transfer belt 40, the toner image is electrostatically transferred to the paper S, and an image can be formed on the paper S.

[0031] The belt cleaning unit 48 removes residual transfer toner remaining on the surface of the intermediate transfer belt 40 after secondary transfer. The belt cleaning unit 48 has a cleaning blade that slides against the surface of the intermediate transfer belt 40.

[0032] As shown in Figure 1, a fixing unit 50 for fixing the toner image to the paper S is provided at the exit side of the secondary transfer nip TN inside the main body 12 of the device. The fixing unit 50 has a heating roller 52, a fixing roller 54, an endless fixing belt 56, and a pressure roller 58.

[0033] The heating roller 52 has a hollow cylindrical core made of, for example, aluminum, iron, or SUS (stainless steel), and a heating device, such as a halogen lamp, provided inside the core. The fixing roller 54 is positioned opposite the heating roller 52. The fixing roller 54 has a hollow cylindrical core made of, for example, aluminum, iron, or SUS, and a surface layer provided on the outer surface of the core, made of, for example, silicone rubber or silicone sponge. The fixing belt 56 is stretched between the heating roller 52 and the fixing roller 54 and is circumferential. The fixing belt 56 has a base material made of, for example, polyimide resin.

[0034] The pressure roller 58 is positioned on the outside of the fixing belt 56, facing the fixing roller 54, and presses toward the fixing roller 54 with a predetermined fixing load. The pressure roller 58 has a hollow cylindrical core made of, for example, aluminum, iron, or stainless steel, an elastic layer made of, for example, silicone rubber, provided on the outer surface of the core, and a surface layer made of, for example, a PFA tube, provided on the surface of the elastic layer. A fixing nip FN is also formed between the fixing roller 54 and the pressure roller 58 for transporting the paper S while heating and pressurizing it.

[0035] As the pressure roller 58 rotates due to the drive of the rotary motor, the fixing belt 56 follows and rotates. As the fixing belt 56 rotates, the heating roller 52 and the fixing roller 54 follow and rotate. This allows the paper S to be transported while being heated and pressurized at the fixing nip FN, thereby fixing any unarrived toner images to the paper S.

[0036] As shown in Figure 1, a paper feeding section 60 for feeding paper S is provided at the bottom of the main body 12 of the device. The paper feeding section 60 has multiple paper trays 62 that can accommodate multiple sheets of paper S. Each paper tray 62 can accommodate a type of paper S that is pre-set according to basis weight, size, etc.

[0037] Downstream of the fixing unit 50 within the main body 12 of the device, there is a paper discharge unit 64 for discharging the image-formed paper S to the outside of the main body 12. The paper discharge unit 64 has a pair of paper discharge rollers 66. The rotation of the pair of paper discharge rollers 66 allows the image-formed paper S to be discharged to the outside of the main body 12.

[0038] As shown in Figure 1, a main transport path 68 is provided between the paper feeding section 60 and the paper discharge section 64 within the main body 12 of the device. The main transport path 68 is the path for transporting the paper S when forming a toner image on the surface of the paper S. The main transport path 68 is the path for transporting the paper S via a plurality of transport roller pairs, including a registration roller pair 70, a secondary transfer nip TN, and a fixing nip FN. In addition, a reversal transport path 72 for reversing the front and back sides of the paper S is provided near the paper feeding section 60 within the main body 12 of the device. The reversal transport path 72 is the path for transporting the paper S when forming a toner image on the back side of the paper S, and is connected to the main transport path 68.

[0039] The paper sheets S placed in the paper feed tray 62 are fed out one by one from the top and transported by the main transport path 68 towards the secondary transfer nip TN. At this time, the tilt of the paper sheets S is corrected by the registration roller pair 70 and the transport timing of the paper sheets S is adjusted. Then, at the secondary transfer nip TN, the toner image from the intermediate transfer belt 40 is transferred all at once to one side (front or back) of the paper sheets S, and at the fixing nip FN, the toner image is fixed to the paper sheets S. After that, the paper sheets S with the formed image are discharged from the paper discharge section 64 to the outside of the main body 12 of the device.

[0040] Next, the configuration of the scanning optical device 32 according to this embodiment will be described with reference to Figures 2 and 3. Figure 2 is a schematic plan cross-sectional view of the scanning optical device 32 according to this embodiment. Figure 3 is a schematic side cross-sectional view of the scanning optical device 32 according to this embodiment.

[0041] As shown in Figures 2 and 3, the scanning optical device 32 includes a housing 76 provided on a partition wall 74 which is part of the main body 12 of the device, and the housing 76 extends in the front-rear direction. The housing 76 is made of die-cast aluminum. The housing 76 has a housing body 78 as a mounting base provided on the partition wall 74, and a cover member 80 that is detachably provided on the upper side of the housing body 78.

[0042] A light source 82 that emits laser light B as scanning light is provided inside the housing 76. A collimator lens (not shown) is provided on the light-emitting side of the light source 82 inside the housing 76 to shape the laser light B from the light source 82 into approximately parallel light. A folding mirror 84 that reflects the laser light B from the light source 82 is provided at a position separated from the light source 82 in the front-rear direction inside the housing 76. The collimator lens and the folding mirror 84 are each optical elements.

[0043] On the left side of the housing 76, there is a polarizer 86 that polarizes the laser light B from the folding mirror 84. The polarizer 86 has a rotatable polygon mirror 88, which is a so-called rotating polyhedron mirror. In addition, multiple scanning lenses 90 that focus the polarized laser light B from the polarizer 86 are provided inside the housing 76 along the optical axis. Each of the multiple scanning lenses 90 is an optical element.

[0044] In the right side of the housing 76, there are multiple folding mirrors 92 that reflect the laser light B from multiple scanning lenses 90, and each folding mirror 92 extends in the front-to-back direction. Also, at a height higher than the scanning lenses 90 in the housing 76, there is a scanning lens 94 that focuses the laser light B from the folding mirrors 92, and the scanning lens 94 also extends in the front-to-back direction. In the left side of the housing 76, there is a glass plate 96 for transmitting the laser light B from the scanning lens 94. A through hole 74h for passing the laser light B is formed in the partition wall 74 at a position opposite the glass plate 96. Note that the multiple folding mirrors 92 and the scanning lens 94 are each optical elements.

[0045] With the above configuration, the laser beam B emitted from the light source 82 passes through the folding mirror 84 and is incident on the mirror surface of the rotating polygon mirror 88. Then, the reflection direction of the laser beam B changes according to the rotation angle of the polygon mirror 88, and the laser beam B is deflected.

[0046] The deflected laser beam B passes through multiple scanning lenses 90 and multiple folding mirrors 92, exits from the scanning lens 94, passes through the glass plate 96, and exits from the through-hole 74h of the partition wall 74. The laser beam B from the through-hole 74h of the partition wall 74 is then deflected in the main scanning direction while its light intensity is modulated according to the image data, and incident on the outer surface of the photoreceptor drum 28. This allows an electrostatic latent image to be formed on the outer surface of the photoreceptor drum 28.

[0047] The configuration of the optical device 98 according to the first embodiment will be described with reference to Figures 3 to 12. Figure 4 is a schematic left side view of the optical device 98 according to the first embodiment. Figure 5 is a schematic right side view of the optical device 98 according to the first embodiment. Figure 6 is an enlarged view along the line VI-VI in Figure 4. Figure 7 is an enlarged view along the line VII-VII in Figure 4. Figure 8 is a schematic cross-sectional view of one end of the optical element 100 in the longitudinal direction in an optical device 98 according to another aspect of the first embodiment.

[0048] Figure 9 is a conceptual diagram of one end of the optical element 100 in the longitudinal direction in the optical device 98 according to the first embodiment. Figure 10 is a conceptual diagram of the other end of the optical element 100 in the longitudinal direction in the optical device 98 according to the first embodiment. Figure 11 is a conceptual diagram of the other end of the optical element 100 in the longitudinal direction in the optical device 98 according to another aspect of the first embodiment. Figure 12 is a conceptual diagram of the optical element 100 along the longitudinal direction in the optical device 98 according to another aspect of the first embodiment.

[0049] As shown in Figures 3 to 8, the optical device 98 according to the first embodiment constitutes a part of the scanning optical device 32 according to this embodiment. The optical device 98 includes an optical element 100 made of float glass, and the optical element 100 is, for example, the uppermost of a plurality of folded mirrors 92. The optical element 100 has a first surface 100a and a second surface 100b on both sides in the thickness direction. The first surface 100a of the optical element 100 is a reflective surface on which metal or silicon dioxide, etc., is deposited. The second surface 100b of the optical element 100 is the back surface located on the opposite side of the first surface 100a.

[0050] As shown in Figures 4 and 5, the optical element 100 is installed between a pair of support columns 102 formed on the housing body 78. The pair of support columns 102 are spaced apart in the front-rear direction and constitute part of the housing body 78 as a mounting base. One support column 102 is located on one end (front end) of the optical element 100 in the longitudinal direction, and the other support column 102 is located on the other end (rear end) of the optical element 100 in the longitudinal direction.

[0051] As shown in Figures 6 and 9, a first seating member 104 is provided in the first recess 102a formed in one of the support columns 102, serving as a first support portion that supports the central portion of the optical element 100 in the short direction on the first surface 100a of the optical element 100. The first seating member 104 is positioned at one end of the optical element 100 in the longitudinal direction. The support portion of the first seating member 104 abuts against the central portion of the optical element 100 in the short direction on the first surface 100a of the optical element 100. The first seating member 104 is made of a steel ball and is configured to be inseparable from the first recess 102a of the support column 102.

[0052] The support portion (contact portion) of the first seating member 104 is in point contact with the first surface 100a of the optical element 100 and is formed in a spherical shape. However, the support portion of the first seating member 104 may be formed in a shape other than a spherical shape as long as it is in point contact with the first surface 100a of the optical element 100. Instead of the first seating member 104 supporting the first surface 100a of the optical element 100, it may support the central portion of the second surface 100b of the optical element 100 in the short-side direction. In this case, the support portion of the first seating member 104 will contact the central portion of the second surface 100b of the optical element 100 in the short-side direction.

[0053] As shown in Figures 4, 6, and 9, a first pressing member 106 is provided on one of the support columns 102 via a mounting screw 108 or the like, which presses the optical element 100 toward the first seating member 104. The first pressing member 106 is positioned on one end of the optical element 100 in the longitudinal direction. The first pressing member 106 is made of a metal leaf spring, such as stainless steel. A boss portion 106b is formed on the first pressing member 106 by drawing, which contacts the second surface 100b of the optical element 100.

[0054] The boss portion 106b of the first pressing member 106, which is the pressing point (contact point), is in point contact with the second surface 100b of the optical element 100 and is formed in a spherical shape. However, the boss portion 106b of the first pressing member 106 may be formed in a shape other than a spherical shape as long as it is in point contact with the second surface 100b of the optical element 100.

[0055] The boss portion 106b of the first pressing member 106 is offset from the portion of the first seating member 104 that faces the support portion of the optical element 100, towards one end in the short direction of the optical element 100. Furthermore, the position of the support portion of the first seating member 104 and the position of the boss portion 106b of the first pressing member 106 in the longitudinal direction of the optical element 100 are the same, but may be at different positions.

[0056] As described above, in the optical device 98, one end of the optical element 100 in the longitudinal direction can be supported at one point (one location) by the support points of the first seating surface member 104. Supporting at one point means supporting one side of the optical element 100 in the thickness direction (first surface 100a or second surface 100b) at one point.

[0057] As shown in Figures 4, 7, and 10, a second seating member 110 is provided in the second recess 102b formed in the other support column 102, serving as a second support portion that supports the portion of the optical element 100 on one end in the short direction of the first surface 100a of the optical element 100. The second seating member 110 is positioned on the other end in the longitudinal direction of the optical element 100. The support portion of the second seating member 110 abuts against the portion of the optical element 100 on one end in the short direction of the first surface 100a of the optical element 100. The support portion of the second seating member 110 is made of a steel ball and is configured to be inseparable from the second recess 102b of the other support column 102.

[0058] The support portion (contact portion) of the second seating member 110 is in point contact with the first surface 100a of the optical element 100 and is formed in a spherical shape. However, the support portion of the second seating member 110 may be formed in a shape other than a spherical shape as long as it is in point contact with the first surface 100a of the optical element 100.

[0059] As shown in Figures 4 and 7, a support bracket 112 is provided on the other support column 102 via mounting screws 114, etc., and the support bracket 112 is positioned on the other end of the optical element 100 in the longitudinal direction. The support bracket 112 is made of a metal sheet, such as stainless steel, and covers a part of the optical element 100 on the other end of the optical element 100 in the longitudinal direction.

[0060] As shown in Figures 4, 7, and 10, the support bracket 112 is provided with a second pressing member 116 via mounting screws 118 or the like, which presses the optical element 100 toward the second seating member 110. The second pressing member 116 is positioned on the other end of the optical element 100 in the longitudinal direction. The second pressing member 116 is made of a metal leaf spring, such as stainless steel. The second pressing member 116 has a boss portion 116b formed by drawing, which contacts a portion of the second surface 100b of the optical element 100 on one end of the optical element 100 in the short direction.

[0061] The boss portion 116b of the second pressing member 116, which is the pressing point (contact point), is in point contact with the second surface 100b of the optical element 100 and is formed in a spherical shape. However, the boss portion 116b of the second pressing member 116 may be formed in a shape other than a spherical shape as long as it is in point contact with the second surface 100b of the optical element 100.

[0062] As shown in Figures 7 and 10, the boss portion 116b of the second pressing member 116 is located opposite the support portion of the second seating member 110, with the optical element 100 in between. As shown in Figure 11, the boss portion 116b of the second pressing member 116 may be shifted from the location opposite the support portion of the second seating member 110 toward one end in the short direction of the optical element 100. Furthermore, the position of the support portion of the second seating member 110 and the position of the boss portion 116b of the second pressing member 116 are the same in the longitudinal direction of the optical element 100, but as shown in Figure 12, they may be at different positions.

[0063] As shown in Figures 4, 7, and 10, the support bracket 112 is provided with an adjustment screw 120, which serves as a third support part or adjustment member, that supports the portion of the optical element 100 on the other end in the short direction of the second surface 100b of the optical element 100. The adjustment screw 120 is located on the other end in the longitudinal direction of the optical element 100. The support point of the adjustment screw 120 abuts against the portion of the optical element 100 on the other end in the short direction of the second surface 100b of the optical element 100. The adjustment screw 120 displaces the support position of the second surface 100b of the optical element 100 by rotating it. The adjustment screw 120 adjusts the rotation angle of the optical element 100 using the support point of the second seating member 110 as a fulcrum by displacing the support position of the second surface 100b of the optical element 100. In other words, the adjustment screw 120 adjusts the orientation of the optical element 100 relative to the housing body 78 by displacing the support position of the second surface 100b of the optical element 100.

[0064] The tip of the adjustment screw 120, which is the support point (contact point), is in point contact with the second surface 100b of the optical element 100 and is formed in a spherical shape. However, the tip of the adjustment screw 120 may be formed in a shape other than spherical as long as it makes point contact with the second surface 100b of the optical element 100. Also, instead of being provided on the support bracket 112, the adjustment screw 120 may be provided at an appropriate position on the housing body 78. The optical device 98 may also be provided with an adjustment pin (not shown) as an adjustment member instead of the adjustment screw 120.

[0065] As shown in Figures 4, 7, and 10, a third pressing member 122 is provided on one of the support columns 102 via a mounting screw 124 or the like, which presses the optical element 100 toward the adjustment screw 120. The third pressing member 122 is positioned on the other end of the optical element 100 in the longitudinal direction. The third pressing member 122 is a leaf spring made of metal such as stainless steel. The third pressing member 122 has a boss portion 122b formed by drawing, which contacts the other end of the optical element 100 in the short direction on the first surface 100a of the optical element 100.

[0066] The boss portion 122b of the third pressing member 122, which is the pressing point (contact point), makes point contact with the first surface 100a of the optical element 100 and is formed in a spherical shape. However, the boss portion 122b of the third pressing member 122 may be formed in a shape other than a spherical shape as long as it makes point contact with the first surface 100a of the optical element 100.

[0067] As shown in Figures 7 and 10, the boss portion 122b of the third pressing member 122 is located opposite the support point of the adjustment screw 120, with the optical element 100 in between. As shown in Figure 11, the boss portion 122b of the third pressing member 122 may be shifted from the location opposite the support point of the adjustment screw 120 to the other end in the short direction of the optical element 100. Furthermore, the position of the support point of the adjustment screw 120 and the position of the boss portion 122b of the third pressing member 122 are the same in the longitudinal direction of the optical element 100.

[0068] As shown in Figures 10 and 12, the position of the support point of the adjustment screw 120 and the position of the boss portion 122b of the third pressing member 122 may be different in the longitudinal direction of the optical element 100. The distance between the support point of the second seating surface member 110 and the pressing point of the second pressing member 116, and the distance between the support point of the adjustment screw 120 and the pressing point of the third pressing member 122 may be the same in the longitudinal direction of the optical element 100. The bending moment due to the pressing force F2 of the second pressing member 116 with the support point of the second seating surface member 110 as the fulcrum, and the bending moment due to the pressing force F3 of the third pressing member 122 with the support point of the adjustment screw 120 as the fulcrum, may act in opposite directions.

[0069] As described above, in the optical device 98, the other end of the optical element 100 in the longitudinal direction can be supported at two points (two locations) by the support points of the second seating member 110 and the support points of the adjustment screw 120. Supporting at two points means supporting one side (first surface 100a or second surface 100b) or both sides (first surface 100a and second surface 100b) of the optical element 100 in the thickness direction at two points.

[0070] Furthermore, in the optical device 98, the rotation angle of the optical element 100 can be adjusted using the support point of the second seating member 110 as a fulcrum by displacing the support position of the second surface 100b of the optical element 100 by rotating the adjustment screw 120. In other words, the orientation of the optical element 100 relative to the housing body 78 can be adjusted.

[0071] Here, since one end of the optical element 100 in the longitudinal direction is supported at one point and the other end is supported at two points, the optical element 100 can be smoothly rotated using the support points of the second seating member 110 as pivot points. Since sufficient distance can be secured between the adjustment screw 120 and the second seating member 110 in the longitudinal direction of the optical element 100, the sensitivity (adjustment sensitivity) of adjusting the posture of the optical element 100 by rotating the adjustment screw 120 can be reduced.

[0072] As shown in Figures 9 to 11, the second pressing member 116 and the third pressing member 122 correspond to pressing parts that press the optical element 100 toward the second seating surface member 110 and the adjustment screw 120. The pressing force (F2 + F3) of the second pressing member 116 and the third pressing member 122 as pressing parts is set to be greater than the pressing force F1 of the first pressing member 106. The pressing force (F2 + F3) of the second pressing member 116 and the third pressing member 122 may be set to be greater than twice the pressing force F1 of the first pressing member 106. The pressing force F2 of the second pressing member 116 may be set to be greater than the pressing force F1 of the first pressing member 106. The pressing force F3 of the third pressing member 122 may be set to be greater than the pressing force F1 of the first pressing member 106.

[0073] In order to set the pressing force F2 of the second pressing member 116 and the pressing force F3 of the third pressing member 122 as described above, the shape, thickness, or material of the second pressing member 116 and the third pressing member 122 may be made different from the shape, thickness, or material of the first pressing member 106. The second pressing member 116 and the third pressing member 122 may each be constructed by stacking two leaf springs identical to the leaf spring that constitutes the first pressing member 106.

[0074] As shown in Figure 6, a side support seat member 126 is provided in the third recess 102c formed in one of the support columns 102, serving as a side support portion that supports the side surface 100c on one end of the optical element 100 in the short direction. The side support seat member 126 is positioned on the other end of the optical element 100 in the longitudinal direction. The support portion of the side support seat member 126 abuts against the side surface 100c of the optical element 100. The side support seat member 126 is made of a steel ball and is configured to be inseparable from the third recess 102c of the support column 102.

[0075] The support portion of the side seating member 126 is in point contact with the side surface 100c of the optical element 100 and is formed in a spherical shape. However, as long as the support portion of the side seating member 126 is in point contact with the side surface 100c of the optical element 100, it may be formed in a shape other than a spherical shape.

[0076] As shown in Figures 4 and 6, one of the support columns 102 is provided with a side pressing member 128 that presses the optical element 100 toward the side seating member 126. The side pressing member 128 is positioned on one end of the optical element 100 in the longitudinal direction. The side pressing member 128 is a leaf spring made of metal such as stainless steel. The side pressing member 128 has a boss portion 128p formed by drawing, which contacts the side surface 100d on the other end of the optical element 100 in the short direction.

[0077] The boss portion 128b of the side pressing member 128, which is the pressing point (contact point), makes point contact with the side surface 100d on the other end in the short direction of the optical element 100, and is formed in a spherical shape. However, if the boss portion 128b of the side pressing member 128 makes point contact with the side surface 100d of the optical element 100, it may be formed in a shape other than a spherical shape.

[0078] The boss portion 128b of the side pressing member 128 is located opposite the support portion of the side seating member 126, with the optical element 100 in between. The boss portion 128b of the side pressing member 128 may be offset in the thickness direction of the optical element 100 from the portion opposite the support portion of the side seating member 126. In addition, the position of the support portion of the side seating member 126 and the position of the boss portion 128b of the side pressing member 128 in the longitudinal direction of the optical element 100 are the same, but may be different.

[0079] The side pressing member 128 has another boss portion (not shown) formed by drawing, which contacts the end face of the other end in the longitudinal direction of the optical element 100. The other boss portion of the side pressing member 128 makes point contact with the end face of the other end in the longitudinal direction of the optical element 100. The boss portion of the side pressing member 128 is formed in a spherical shape.

[0080] Instead of providing a side pressing member 128 made of a leaf spring on one of the support columns 102, the following may be used: As shown in Figure 8, a retaining bracket 130 made of sheet metal may be provided on one of the support columns 102. Between the back surface of the retaining bracket 130 and the other side surface 100d of the optical element 100 in the short direction, another side pressing member 132 made of an elastic material such as vibration-damping rubber may be provided. The other side pressing member 132 presses the optical element 100 toward the side seating member 126 with its elastic force.

[0081] As shown in Figure 7, a side support member 134 is provided in the fourth recess 102d formed in the other support column 102, serving as a side support portion that supports the side surface 100c on one end of the optical element 100 in the short direction. The side support member 134 is positioned on the other end of the optical element 100 in the longitudinal direction. The support portion of the side support member 134 abuts against the side surface 100c of the optical element 100. The side support member 134 is made of a steel ball and is configured to be inseparable from the fourth recess 102d of the other support column 102.

[0082] The support portion (contact portion) of the side seating member 134 is in point contact with the side surface 100c of the optical element 100 and is formed in a spherical shape. However, the support portion of the side seating member 134 may be formed in a shape other than spherical as long as it is in point contact with the side surface 100c of the optical element 100.

[0083] The support bracket 112 has a boss portion 106b formed by drawing, which is located close to the side surface 100d of the other end of the optical element 100 in the short direction, at a distance of approximately 0.5 mm. The boss portion 112b of the support bracket 112 is formed in a spherical shape. The boss portion 112b of the support bracket 112 may abut against the side surface 100d of the optical element 100.

[0084] The boss portion 112b of the support bracket 112 is located opposite the support point of the side seating member 134, with the optical element 100 in between. The boss portion 112b of the support bracket 112 may be offset in the thickness direction of the optical element 100 from the point opposite the support point of the side seating member 134. Also, the position of the support point of the side seating member 134 and the position of the boss portion 112b of the support bracket 112 in the longitudinal direction of the optical element 100 are the same, but they may be different.

[0085] Here, the side seating member 134 and the boss portion 112b of the support bracket 112 correspond to detachment restrictors that restrict the optical element 100 from falling off the second seating member 110 and the adjustment screw 120 by restricting the in-plane movement of the optical element 100. In other words, the optical device 98 includes the side seating member 134 and the boss portion 112b of the support bracket 112 as detachment restrictors. The in-plane direction of the optical element 100 refers to the direction perpendicular to the thickness direction of the optical element 100. Furthermore, as described above, the side seating member 134 and the boss portion 112b of the support bracket 112 are configured to be in a non-pressing state relative to the optical element 100 as detachment restrictors.

[0086] The support bracket 112 has another boss portion (not shown) formed by drawing, which contacts the end face of one end of the optical element 100 in the longitudinal direction. This other boss portion of the support bracket 112 makes point contact with the end face of the other end of the optical element 100 in the longitudinal direction. The other boss portion of the support bracket 112, which is the support point, is formed in a spherical shape.

[0087] As shown in Figures 4 and 5, a reinforcing member 136 is attached to the central part of the optical element 100 in the longitudinal direction on the second surface 100b of the optical element 100. The reinforcing member 136 extends in the longitudinal direction of the optical element 100 and is made of sheet metal.

[0088] According to the configuration of the optical device 98 in the first embodiment, as described above, the pressing force (F2 + F3) of the second pressing member 116 and the third pressing member 122 is set to be greater than the pressing force F1 of the first pressing member 106. Therefore, compared to the case where the pressing force (F2 + F3) of the second pressing member 116 and the third pressing member 122 is the same as the pressing force F1 of the first pressing member 106, the optical element 100 can be pressed with greater force towards the second seating surface member 110 and the adjustment screw 120.

[0089] Accordingly, according to the optical device 98 of the first embodiment, when one end of the optical element 100 in the longitudinal direction is supported at one point and the other end is supported at two points, the lifting of the optical element 100 from the second seating surface member 110 and the adjustment screw 120 can be suppressed. As a result, the rotational vibration of the optical element 100 around the axis along the longitudinal direction of the optical element 100 can be reduced, thereby improving the image quality of the image forming apparatus 10. In particular, when the optical element 100 is a folded mirror 92 (an example of a mirror), the influence of the rotational vibration of the optical element 100 on the direction of propagation of the laser light B as scanning light can be reduced.

[0090] Furthermore, according to the configuration of the optical device 98 according to the first embodiment, as described above, the pressing force (F2 + F3) of the second pressing member 116 and the third pressing member 122 is set to be greater than twice the pressing force F1 of the first pressing member 106. Therefore, compared to the case where the pressing force (F2 + F3) of the second pressing member 116 and the third pressing member 122 is the same as the pressing force F1 of the first pressing member 106, the optical element 100 can be pressed with a stronger force on the second seating surface member 110 side and the adjustment screw 120 side.

[0091] Therefore, according to the optical device 98 of the first embodiment, even if there is variation in the rotational moment of the optical element 100 due to the pressing force F1 of the first pressing member 106, the lifting of the optical element 100 from the second seating member 110 and the adjustment screw 120 can be further suppressed.

[0092] Furthermore, according to the configuration of the optical device 98 according to the first embodiment, as described above, the pressing force F2 of the second pressing member 116 and the pressing force F3 of the third pressing member 122 are each set to be greater than the pressing force F1 of the first pressing member 106. Therefore, the optical element 100 can be stably pressed with strong force towards the second seating surface member 110 and the adjustment screw 120.

[0093] Therefore, according to the optical device 98 of the first embodiment, the lifting of the optical element 100 from the second seating member 110 and the adjustment screw 120 can be stably suppressed.

[0094] Furthermore, according to the configuration of the optical device 98 according to the first embodiment, the distance between the support point of the second seating member 110 and the pressing point of the second pressing member 116 is the same as the distance between the support point of the adjustment screw 120 and the pressing point of the third pressing member 122. The bending moment due to the pressing force F2 of the second pressing member 116 with the support point of the second seating member 110 as the fulcrum, and the bending moment due to the pressing force F3 of the third pressing member 122 with the support point of the adjustment screw 120 as the fulcrum, act in opposite directions. Therefore, the bending moment due to the pressing force F2 of the second pressing member 116 and the bending moment due to the pressing force F3 of the third pressing member 122 cancel each other out.

[0095] Therefore, according to the optical device 98 of the first embodiment, bending deformation of the optical element 100 can be suppressed.

[0096] Furthermore, according to the configuration of the optical device 98 according to the first embodiment, as described above, the first seating member 104 and the second seating member 110 each support the first surface 100a of the optical element 100. Therefore, the first recess 102a, which is the installation location for the first seating member 104, and the second recess 102b, which is the installation location for the second seating member 110, can be processed simultaneously in the same process.

[0097] Therefore, according to the optical device 98 of the first embodiment, the machining accuracy of the first recess 102a and the second recess 102b can be improved.

[0098] In particular, when the first surface 100a of the optical element 100 is the reflective surface of the folded mirror 92, even if a dimensional error occurs in the thickness direction of the optical element 100, the positional error of the reflective surface of the folded mirror 92 can be reduced.

[0099] Furthermore, according to the configuration of the optical device 98 according to the first embodiment, as described above, the side seating member 126 supports the side surface 100c on one end of the optical element 100 in the short direction. The side pressing member 128 presses the optical element 100 toward the side seating member 126. Therefore, the optical element 100 can be stably held by the frictional force between the side seating member 126 and the optical element 100, and the frictional force between the side pressing member 128 and the optical element 100. In particular, when the side seating member 126 and the side pressing member 128 are arranged toward the other end of the optical element 100 in the longitudinal direction, the optical element 100 can be held stably and effectively.

[0100] Therefore, according to the optical device 98 of the first embodiment, the lifting of the optical element 100 from the second seating member 110 and the adjustment screw 120 can be further suppressed, and the rotational vibration of the optical element 100 can be further reduced.

[0101] Furthermore, according to the configuration of the optical device 98 according to the first embodiment, as described above, the side seating member 134 and the boss portion 112b of the support bracket 112, acting as detachment restrictors, restrict the detachment of the optical element 100 from the second seating member 110 and the adjustment screw 120. As detachment restrictors, the side seating member 134 and the boss portion 112b of the support bracket 112 are configured to be in a non-pressing state with respect to the optical element 100. Therefore, it is possible to prevent the frictional force between the side seating member 134, the boss portion 112b of the support bracket 112 and the optical element 100 from becoming excessive, while suppressing the lifting of the optical element 100 from the adjustment screw 120 by that frictional force.

[0102] Therefore, according to the optical device 98 of the first embodiment, the responsiveness of the optical element 100 to the operation (rotation) of the adjustment screw 120 can be improved, thereby improving the workability of the adjustment work of the optical element 100.

[0103] Furthermore, according to the configuration of the optical device 98 in the first embodiment, as described above, a reinforcing member 136 is attached to the central part of the optical element 100 in the longitudinal direction on the second surface 100b of the optical element 100. Therefore, even if a rotational moment is generated that presses the optical element 100 against the second seating surface member 110 and the adjustment screw 120, torsional deformation of the optical element 100 can be suppressed.

[0104] Therefore, according to the optical device 98 of the first embodiment, the influence of its rotational moment on the performance of the optical device 98 can be suppressed.

[0105] Furthermore, according to the configuration of the optical device 98 according to the first embodiment, as described above, the boss portion 106b of the first pressing member 106, the boss portion 116b of the second pressing member 116, and the boss portion 122b of the third pressing member 122 each make point contact with the optical element 100. Therefore, compared to cases where the optical element 100 is in line contact or surface contact, the boss portion 106b of the first pressing member 106, etc., can be made to make stable contact with the optical element 100, thereby reducing friction between the boss portion 106b of the first pressing member 106, etc., and the optical element 100. In particular, by forming the boss portion 106b of the first pressing member 106, etc., in a spherical shape, the boss portion 106b of the first pressing member 106, etc., can be made to make stable contact with the optical element 100, thereby further reducing friction between the boss portion 106b of the first pressing member 106, etc., and the optical element 100.

[0106] Therefore, according to the optical device 98 of the first embodiment, the lifting of the optical element 100 from the second seating member 110 and the adjustment screw 120 can be further suppressed, and the responsiveness of the optical element 100 to the operation of the adjustment screw 120 can be improved.

[0107] Furthermore, according to the configuration of the optical device 98 according to the first embodiment, as described above, the support points of the first seating member 104, the support points of the second seating member 110, and the support points of the adjustment screw 120 each make point contact with the optical element 100. Therefore, compared to cases where the optical element 100 is in line contact or surface contact, the support points of the first seating member 104, etc. can be made to make stable contact with the optical element 100, thereby reducing friction between the support points of the first seating member 104, etc. and the optical element 100. In particular, by forming the support points of the first seating member 104, etc. in a spherical shape, the support points of the first seating member 104, etc. can be made to make stable contact with the optical element 100, thereby further reducing friction between the support points of the first seating member 104, etc. and the optical element 100.

[0108] Therefore, according to the optical device 98 of the first embodiment, the lifting of the optical element 100 from the second seating member 110 and the adjustment screw 120 can be further suppressed, and the responsiveness of the optical element 100 to the operation of the adjustment screw 120 can be improved.

[0109] The configuration of the optical device 138 according to the second embodiment will be described with reference to Figures 3 to 7, 13, and 14. Figure 13 is a conceptual diagram of one end of the optical element 140 in the longitudinal direction in the optical device 138 according to the second embodiment. Figure 14 is a conceptual diagram of the other end of the optical element 140 in the longitudinal direction in the optical device 138 according to the second embodiment.

[0110] As shown in Figures 3 to 5, the optical device 138 according to the second embodiment constitutes a part of the scanning optical device 32 according to this embodiment. The optical device 138 includes an optical element 140 made of float glass, and the optical element 140 is, for example, the rightmost folding mirror 92 among a plurality of folding mirrors 92. The optical element 140 has a first surface 140a and a second surface 140b on both sides in the thickness direction. The first surface 140a of the optical element 140 is a reflective surface on which metal or silicon dioxide, etc., is deposited. The second surface 140b of the optical element 140 is the back surface located on the opposite side of the first surface 140a. The optical element 140 is also installed between a pair of support columns 102 formed in the housing body 78.

[0111] As shown in Figures 6 and 13, a first seating member 142 is provided in the fifth recess 102e formed in one of the support columns 102, serving as a first support portion that supports the central portion of the optical element 140 in the short direction on the first surface 140a of the optical element 140. The first seating member 142 is positioned at one end of the optical element 140 in the longitudinal direction. The support portion of the first seating member 142 abuts against the central portion of the optical element 140 in the short direction on the first surface 140a of the optical element 140. The first seating member 142 is made of a steel ball and is configured to be inseparable from the fifth recess 102e of the support column 102.

[0112] The support portion (contact portion) of the first seating member 142 is in point contact with the first surface 140a of the optical element 140 and is formed in a spherical shape. However, the support portion of the first seating member 142 may be formed in a shape other than a spherical shape as long as it is in point contact with the first surface 140a of the optical element 140. Instead of the first seating member 142 supporting the first surface 140a of the optical element 140, it may support the central portion of the optical element 140 on the second surface 140b in the short-side direction. In this case, the support portion of the first seating member 142 will contact the central portion of the optical element 140 on the second surface 140b in the short-side direction.

[0113] As shown in Figures 5, 6, and 13, a first pressing member 144 is provided on one of the support columns 102 via a mounting screw 146 or the like, which presses the optical element 140 toward the first seating member 142. The first pressing member 144 is positioned on one end of the optical element 140 in the longitudinal direction. The first pressing member 144 is made of a metal leaf spring, such as stainless steel. A boss portion 144b is formed on the first pressing member 144 by drawing, which contacts the second surface 140b of the optical element 140.

[0114] The boss portion 144b of the first pressing member 144, which is the pressing point (contact point), is in point contact with the second surface 140b of the optical element 140 and is formed in a spherical shape. However, the boss portion 144b of the first pressing member 144 may be formed in a shape other than a spherical shape as long as it is in point contact with the second surface 140b of the optical element 140.

[0115] The boss portion 144b of the first pressing member 144 is located opposite the support portion of the first seating member 142, with the optical element 140 in between. Furthermore, the position of the support portion of the first seating member 142 and the position of the boss portion 144b of the first pressing member 144 are the same in the longitudinal direction of the optical element 140, but they may be at different positions.

[0116] As described above, in the optical device 138, one end of the optical element 140 in the longitudinal direction can be supported at one point (one location) by the support points of the first seating surface member 142. Supporting at one point means supporting one side of the optical element 140 in the thickness direction (first surface 140a or second surface 140b) at one point.

[0117] As shown in Figure 7, a second seating member 148 is provided in the sixth recess 102f formed in the other support column 102, serving as a second support portion that supports the portion of the optical element 140 on one end in the short direction of the first surface 140a of the optical element 140. The second seating member 148 is positioned on the other end in the longitudinal direction of the optical element 140. The support portion of the second seating member 148 abuts against the portion of the optical element 140 on one end in the short direction of the first surface 140a of the optical element 140. The second seating member 148 is made of a steel ball and is configured to be inseparable from the sixth recess 102f of the other support column 102.

[0118] The support portion (contact portion) of the second seating member 148 is in point contact with the first surface 140a of the optical element 140 and is formed in a spherical shape. However, the support portion of the second seating member 148 may be formed in a shape other than a spherical shape as long as it is in point contact with the first surface 140a of the optical element 140.

[0119] A third support member 150 is provided in the seventh recess 102g formed in the other support column 102, serving as a third support portion that supports the portion of the optical element 140 on the other end in the short direction of the first surface 140a of the optical element 140. The third support member 150 is positioned on the other end in the longitudinal direction of the optical element 100. The third support member 150 abuts against the portion of the optical element 140 on the other end in the short direction of the first surface 140a of the optical element 140. The third support member 150 is made of a steel ball and is configured to be inseparable from the seventh recess 102g of the other support column 102.

[0120] The support portion (contact portion) of the third seating member 150 is in point contact with the first surface 140a of the optical element 140 and is formed in a spherical shape. The support portion of the third seating member 150 may be formed in a shape other than spherical as long as it is in point contact with the first surface 140a of the optical element 140. In addition, the position of the support portion of the second seating member 148 and the position of the support portion of the third seating member 150 in the longitudinal direction of the optical element 140 are the same, but they may be in different positions.

[0121] As shown in Figures 5, 7, and 14, the other support column 102 is provided with a pressing portion 152 via mounting screws 154 or the like that presses the optical element 140 toward the second seating member 148 and the third seating member 150. The pressing portion 152 presses the portion of the second surface 140b of the optical element 140 between the portion facing the support point of the second seating member 148 and the portion facing the support point of the third seating member 150, with the optical element 140 in between. The pressing portion 152 is located on the other end side in the longitudinal direction of the optical element 140. The pressing portion 152 is made of a metal leaf spring, such as stainless steel. The pressing portion 152 has a boss portion 152b formed by drawing, which contacts the second surface 140b of the optical element 140.

[0122] The boss portion 152b of the pressing portion 152, which is the pressing point (contact point), is in point contact with the second surface 140b of the optical element 140 and is formed in a spherical shape. The boss portion 152b of the pressing portion 152 may be formed in a shape other than a spherical shape as long as it is in point contact with the second surface 140b of the optical element 140. In addition, the position of the support point of the second seating member 148 (third seating member 150) and the position of the boss portion 152b of the pressing portion 152 in the longitudinal direction of the optical element 140 are the same, but they may be in different positions.

[0123] As described above, in the optical device 138, the other end of the optical element 140 in the longitudinal direction can be supported at two points (two locations) by the support points of the second seating member 148 and the third seating member 150. Supporting at two points means supporting one side (first surface 140a or second surface 140b) or both sides (first surface 140a and second surface 140b) of the optical element 140 in the thickness direction at two points.

[0124] As shown in Figures 13 and 14, the pressing force Fa of the pressing portion 152 is set to be greater than the pressing force F1 of the first pressing member 144. The pressing force Fa of the pressing portion 152 may also be set to be greater than twice the pressing force F1 of the first pressing member 144. In order to set the pressing force Fa of the pressing portion 152 as described above, the shape, thickness, or material of the pressing portion 152 may be different from the shape, thickness, or material of the first pressing member 144. The pressing portion 152 may be constructed by stacking two leaf springs identical to the leaf springs that make up the first pressing member 144.

[0125] As shown in Figures 5, 6, and 13, an eighth recess 102h formed in one of the support columns 102 is provided with a side support member 156, which serves as a side support for supporting the side surface 140c on one end of the optical element 140 in the short direction. The side support member 156 is positioned on one end of the optical element 140 in the longitudinal direction. The support portion of the side support member 156 abuts against the side surface 140c of the optical element 140. The side support member 156 is made of a steel ball and is configured to be inseparable from the eighth recess 102h of the support column 102.

[0126] The support portion (contact portion) of the side seating member 156 is in point contact with the side surface 140c of the optical element 140 and is formed in a spherical shape. However, the support portion of the side seating member 156 may be formed in a shape other than spherical as long as it is in point contact with the side surface 140c of the optical element 140.

[0127] As shown in Figures 5 and 6, one of the support columns 102 is provided with a side pressing member 158 that presses the optical element 140 toward the side seating member 156, and the side pressing member 158 is positioned on one end of the optical element 140 in the longitudinal direction. The side pressing member 158 is a leaf spring made of metal such as stainless steel. The side pressing member 158 has a boss portion 158b formed by drawing, which contacts the side surface 140d on the other end of the optical element 140 in the short direction.

[0128] The boss portion 158b of the side pressing member 158, which is the pressing point (contact point), makes point contact with the side surface 140d of the optical element 140 and is formed in a spherical shape. However, if the boss portion 158b of the side pressing member 158 makes point contact with the side surface 140d of the optical element 140, it may be formed in a shape other than a spherical shape.

[0129] The boss portion 158b of the side pressing member 158 is located opposite the support portion of the side seating member 156, with the optical element 140 in between. The boss portion 158b of the side pressing member 158 may be offset in the thickness direction of the optical element 140 from the portion opposite the support portion of the side seating member 156. Furthermore, the position of the boss portion 158b of the side pressing member 158 in the longitudinal direction of the optical element 140 is the same as the position of the support portion of the side seating member 156, but it may be a different position.

[0130] The side pressing member 158 has another boss portion (not shown) formed by drawing, which contacts the end face of one end of the optical element 140 in the longitudinal direction. The other boss portion of the side pressing member 158 makes point contact with the end face of one end of the optical element 140 in the longitudinal direction. The other boss portion of the side pressing member 158 is formed in a spherical shape.

[0131] As shown in Figure 7, a side support member 160 is provided in the ninth recess 102i formed in the other support column 102, serving as a side support portion for supporting the side surface 140d on the other end in the short direction of the optical element 140. The side support member 160 is positioned on the other end in the longitudinal direction of the optical element 140. The support portion of the side support member 160 abuts against the side surface 140d of the optical element 140. The side support member 160 is made of a steel ball and is configured to be inseparable from the ninth recess 102i of the other support column 102.

[0132] The support portion (contact portion) of the side seating member 160 is in point contact with the side surface 140c of the optical element 140 and is formed in a spherical shape. However, the support portion of the side seating member 160 may be formed in a shape other than a spherical shape as long as it is in point contact with the side surface 140c of the optical element 140.

[0133] As shown in Figure 7, a retaining bracket 162 is provided on the other support column 102, and the retaining bracket 162 is made of sheet metal. Between the back surface of the retaining bracket 162 and the side surface 140d of the optical element 140, a plate-shaped side pressing member 164 is provided to press the optical element 140 toward the side seating member 160. The side pressing member 164 is made of an elastic material such as vibration-damping rubber.

[0134] The retaining bracket 162 has a boss portion (not shown) formed by drawing, which contacts the end face of the other end of the optical element 140 in the longitudinal direction. The boss portion of the retaining bracket 162 makes point contact with the end face of the other end of the optical element 140 in the longitudinal direction. The boss portion of the retaining bracket 162 is formed in a spherical shape.

[0135] As shown in Figure 5, a reinforcing member 166 is attached to the central part of the optical element 140 in the longitudinal direction on the second surface 140b of the optical element 140. The reinforcing member 166 extends in the longitudinal direction of the optical element 140 and is made of sheet metal.

[0136] According to the configuration of the optical device 138 in the second embodiment, as described above, the pressing force Fa of the pressing portion 152 is set to be greater than the pressing force F1 of the first pressing member 144. Therefore, compared to the case where the pressing force Fa of the pressing portion 152 is the same as the pressing force F1 of the first pressing member 144, the optical element 140 can be pressed with a stronger force towards the second seating surface member 148 and the third seating surface member 150.

[0137] Accordingly, according to the optical device 138 of the second embodiment, when one end of the optical element 140 in the longitudinal direction is supported at one point and the other end is supported at two points, the lifting of the optical element 140 from the second seating member 148 and the third seating member 150 can be suppressed. As a result, the rotational vibration of the optical element 140 around its axis along the longitudinal direction can be reduced, thereby improving the image quality of the image forming apparatus 10. In particular, when the optical element 140 is a folded mirror 92 (an example of a mirror), the influence of the rotational vibration of the optical element 140 on the direction of propagation of the laser light B as scanning light can be reduced.

[0138] Furthermore, according to the configuration of the optical device 138 in the second embodiment, as described above, the pressing force Fa of the pressing portion 152 is set to be greater than twice the pressing force F1 of the first pressing member 144. Therefore, compared to the case where the pressing force Fa of the pressing portion 152 is the same as the pressing force F1 of the first pressing member 144, the optical element 140 can be pressed with a stronger force towards the second seating surface member 148 and the third seating surface member 150.

[0139] Therefore, according to the optical device 138 of the second embodiment, even if there is variation in the rotational moment of the optical element 140 due to the pressing force F1 of the first pressing member 144, the lifting of the optical element 140 from the second seating member 148 and the like can be further suppressed.

[0140] Furthermore, according to the configuration of the optical device 138 in the second embodiment, as described above, the first seating member 142 and the second seating member 148 each support the first surface 140a of the optical element 140. Therefore, the fifth recess 102e, where the first seating member 142 is installed, and the sixth recess 102f, where the second seating member 148 is installed, can be processed simultaneously in the same process.

[0141] Therefore, according to the optical device 138 of the second embodiment, the machining accuracy of the fifth recess 102e and the sixth recess 102f can be improved.

[0142] In particular, when the first surface 140a of the optical element 140 is the reflective surface of the folded mirror 92, even if a dimensional error occurs in the thickness direction of the optical element 140, the positional error of the reflective surface of the folded mirror 92 can be reduced.

[0143] Furthermore, according to the configuration of the optical device 138 in the second embodiment, as described above, the side seating member 156 supports the side surface 140c on one end of the optical element 140 in the short direction. The side pressing member 158 presses the optical element 140 toward the side seating member 156. Therefore, the optical element 140 can be stably held by the frictional force between the side seating member 156 and the optical element 140, and the frictional force between the side pressing member 158 and the optical element 140.

[0144] Therefore, according to the optical device 138 of the second embodiment, the lifting of the optical element 140 from the second seating member 148 and the third seating member 150 can be further suppressed, and the rotational vibration of the optical element 140 can be further reduced.

[0145] Furthermore, according to the configuration of the optical device 138 in the second embodiment, as described above, a reinforcing member 166 is attached to the central part of the optical element 140 in the longitudinal direction on the second surface 140b of the optical element 140. Therefore, even if a rotational moment is generated that presses the optical element 140 against the second seating member 148 and the third seating member 150, torsional deformation of the optical element 140 can be suppressed.

[0146] Therefore, according to the optical device 138 of the second embodiment, the influence of its rotational moment on the performance of the optical device 138 can be suppressed.

[0147] The configuration of the optical device 138A according to a modified example of the second embodiment will be described with reference to Figures 3, 15, and 16. Figure 15 is a conceptual diagram of the other end in the longitudinal direction of the optical element 140 in the optical device 138A according to a modified example of the second embodiment. Figure 16 is a conceptual diagram of the optical element 140 along the longitudinal direction in the optical device 138A according to a modified example of the second embodiment.

[0148] As shown in Figures 3 and 15, the scanning optical device 32 according to this embodiment may include an optical device 138A according to a modified example of the second embodiment instead of the optical device 138 according to the second embodiment. The optical device 138A has the following configuration instead of including the pressing portion 152 (see Figure 14) of the optical device 138. For the sake of explanation, the same reference numerals are used for components that have the same function as those described in the second embodiment, and their descriptions are not repeated.

[0149] As shown in Figure 15, the other support column 102 (see Figure 5) is provided with a second pressing member 168 that presses the optical element 140 toward the second seating member 148, and the second pressing member 168 is positioned on the other end of the optical element 140 in the longitudinal direction. The second pressing member 168 is made of a metal leaf spring, such as stainless steel. The second pressing member 168 has a boss portion 168b formed by drawing, which contacts the portion of the second surface 140b of the optical element 140 on one end of the optical element 140 in the short direction.

[0150] The boss portion 168b of the second pressing member 168 makes point contact with the second surface 140b of the optical element 140. The boss portion 168b, which is the pressing point (contact point) of the second pressing member 168, is formed in a spherical shape. However, if the boss portion 168b of the second pressing member 168 makes point contact with the second surface 140b of the optical element 140, it may be formed in a shape other than a spherical shape.

[0151] The other support column 102 is provided with a third pressing member 170 that presses the optical element 140 toward the third seating member 150, and the third pressing member 170 is positioned on the other end of the optical element 140 in the longitudinal direction. The third pressing member 170 is made of a metal leaf spring, such as stainless steel. The third pressing member 170 has a boss portion 170b formed by drawing, which contacts the other end of the optical element 140 in the short direction on the second surface 140b of the optical element 140.

[0152] The boss portion 170b of the third pressing member 170 makes point contact with the second surface 140b of the optical element 140. The boss portion 170b of the third pressing member 170, which is the pressing point (contact point), is formed in a spherical shape. However, if the boss portion 170b of the third pressing member 170 makes point contact with the second surface 140b of the optical element 140, it may be formed in a shape other than a spherical shape.

[0153] As shown in Figures 15 and 16, the position of the boss portion 168b of the second pressing member 168 and the position of the boss portion 170b of the third pressing member 170 in the longitudinal direction of the optical element 140 may be different. The distance between the support point of the second seating member 148 and the boss portion 168b of the second pressing member 168, and the distance between the support point of the third seating member 150 and the boss portion 170b of the third pressing member 170 in the longitudinal direction of the optical element 140 may be the same. The bending moment due to the pressing force F2 of the second pressing member 168 with the support point of the second seating member 148 as the fulcrum, and the bending moment due to the pressing force F3 of the third pressing member 170 with the support point of the third seating member 150 as the fulcrum, may act in opposite directions.

[0154] As described above, in the optical device 138A, one end of the optical element 140 in the longitudinal direction can be supported at one point (one location) by the support points of the first seating member 142. The other end of the optical element 140 in the longitudinal direction can be supported at two points (two locations) by the support points of the second seating member 148 and the third seating member 150.

[0155] As shown in Figure 15, the second pressing member 168 and the third pressing member 170 correspond to pressing parts that press the optical element 140 toward the second seating member 148 and the third seating member 150. The pressing force (F2 + F3) of the second pressing member 168 and the third pressing member 170 as pressing parts is set to be greater than the pressing force F1 of the first pressing member 144 (see Figure 13). The pressing force (F2 + F3) of the second pressing member 168 and the third pressing member 170 may be set to be greater than twice the pressing force F1 of the first pressing member 144. The pressing force F2 of the second pressing member 168 may be set to be greater than the pressing force F1 of the first pressing member 144. The pressing force F3 of the third pressing member 170 may be set to be greater than the pressing force F1 of the first pressing member 144.

[0156] In order to set the pressing force F2 of the second pressing member 168 and the pressing force F3 of the third pressing member 170 as described above, the shape, thickness, or material of the second pressing member 168 and the third pressing member 170 may be different from the shape, thickness, or material of the first pressing member 144. The second pressing member 168 and the third pressing member 170 may each be constructed by stacking two leaf springs identical to the leaf springs that make up the first pressing member 144.

[0157] According to the configuration of the optical device 138A, a modified version of the second embodiment, as described above, the pressing force (F2 + F3) of the second pressing member 168 and the third pressing member 170 is set to be greater than the pressing force F1 of the first pressing member 144. Therefore, compared to the case where the pressing force (F2 + F3) of the second pressing member 168 and the third pressing member 170 is the same as the pressing force F1 of the first pressing member 144, the optical element 140 can be pressed with greater force towards the second seating member 148 and the third seating member 150.

[0158] Accordingly, according to the optical device 138A of the modified second embodiment, when one end of the optical element 140 in the longitudinal direction is supported at one point and the other end is supported at two points, the lifting of the optical element 140 from the second seating surface member 148, etc., can be suppressed. As a result, the rotational vibration of the optical element 140 around the axis along the longitudinal direction of the optical element 140 can be reduced, and the image quality of the image forming apparatus 10 can be improved. In particular, when the optical element 140 is a folded mirror 92 (an example of a mirror), the influence of the rotational vibration of the optical element 140 on the direction of propagation of the laser light B as scanning light can be reduced.

[0159] Furthermore, according to the configuration of the optical device 138A, which is a modified example of the second embodiment, as described above, the pressing force (F2 + F3) of the second pressing member 168 and the third pressing member 170 is set to be greater than twice the pressing force F1 of the first pressing member 144. Therefore, compared to the case where the pressing force (F2 + F3) of the second pressing member 168 and the third pressing member 170 is the same as the pressing force F1 of the first pressing member 144, the optical element 140 can be pressed with a stronger force towards the second seating member 148 and the third seating member 150.

[0160] Therefore, according to the optical device 138A of the modified second embodiment, even if there is variation in the rotational moment of the optical element 140 due to the pressing force F1 of the first pressing member 144, the lifting of the optical element 140 from the second seating surface member 148 and the like can be further suppressed.

[0161] Furthermore, according to the configuration of the optical device 138A, which is a modified version of the second embodiment, as described above, the pressing force F2 of the second pressing member 168 and the pressing force F3 of the third pressing member 170 are each set to be greater than the pressing force F1 of the first pressing member 144. Therefore, the optical element 140 can be stably pressed with strong force against the second seating surface member 148 side and the third seating surface member 150 side.

[0162] Therefore, according to the optical device 138 of the modified second embodiment, the lifting of the optical element 140 from the second seating member 148 and the third seating member 150 can be stably suppressed.

[0163] Furthermore, according to the configuration of the optical device 138 as a modified example of the second embodiment, the distance between the support point of the second seating member 148 and the boss portion 168b of the second pressing member 168 is the same as the distance between the support point of the third seating member 150 and the boss portion 170b of the third pressing member 170. The bending moment due to the pressing force F2 of the second pressing member 168 with the support point of the second seating member 148 as the fulcrum, and the bending moment due to the pressing force F3 of the third pressing member 170 with the support point of the third seating member 150 as the fulcrum, act in opposite directions. Therefore, the bending moment due to the pressing force F2 of the second pressing member 168 and the bending moment due to the pressing force F3 of the third pressing member 122 cancel each other out.

[0164] Therefore, according to the optical device 138A of the modified second embodiment, bending deformation of the optical element 140 can be suppressed.

[0165] Although this embodiment has been described in detail above, the present invention is not limited to the specific embodiments described above. For example, an optical element other than the folding mirror 92 may be used as the optical element 100 of the optical device 98, and an optical element other than the folding mirror 92 may be used as the optical element 140 of the optical device 138 (138A). Furthermore, various modifications and changes are possible to the specific examples described above within the scope of the gist of the present invention as described in the claims. [Industrial applicability]

[0166] The present invention is useful as an optical device, a scanning optical device, and an image forming apparatus, as it can suppress the lifting of the optical element from the second and third support parts when one end of the optical element in the longitudinal direction is supported at one point and the other end is supported at two points. [Explanation of Symbols]

[0167] 10 Image forming apparatus 12 Main unit of the device 14 Image reading unit 16 CCD sensors 18 Image Processing Unit 20. Manuscript transport section 22 Operation display section 24 Image forming unit 26 Image forming unit 26C Image Forming Unit 26K Image Forming Unit 26M Image Forming Unit 26Y Image Forming Unit 28 Photoconductor Drum 30 Charged parts 32 Scanning optical device (exposure unit) 34. Developing Department 36 Drum Cleaning Section 38 Transfer section 40 Intermediate transfer belt 42 Support rollers 44 Primary transfer roller 46 Secondary transfer roller 48 Belt Cleaning Section 50 Fixing section 52 heating rollers 54 Fixing roller 56 Fixing belt 58 Pressure Roller 60 Paper feed section 62 Paper feed tray 64 Paper output section 66 Paper output roller pair 68 Main transport path 70 Resist Roller 72 Reversal transport path 74 Bulkhead 74h through hole 76 Housing 78 Housing body (mounting base) 80 Cover component 82 Light source 84 Folding mirror 86. Optical polarizer 88 Polygon Mirror 90 scanning lens 92 Folding mirror 94 scanning lens 96 Glass plate 98 Optical equipment 100 optical elements 100a First surface (reflective surface) 100b 2nd side (back) 100c side 100d side view 102 Pillar section 102a First recess 102b Second recess 102c Third recess 102d Fourth recess 102e Fifth recess 102f 6th recess 102g 7th recess 102h 8th recess 102i 9th recess 104 First seat member (first support part) 106 First pressing member 106b Boss section 108 Mounting screws 110 Second seat member (second support part) 112 Support bracket 114 Mounting screws 116 Second pressing member 116b Boss section 118 Mounting screws 120 Adjustment screw (3rd support part, adjustment member) 122b Boss section 122 Third pressing member 124 Mounting screws 126 Side seat member (side support part) 128 Side pressing member 128b Boss section 130 Retaining bracket 132 Side pressing member 134 Side seat member (side support part) 136 Reinforcement member 138 Optical equipment 138A Optical equipment 140 optical elements 140a 1st surface (reflective surface) 140b 2nd side (back) 140c side 140d side 142 First seat member (first support part) 144 First pressing member 144b Boss section 146 Mounting screws 148 Second seat member (second support part) 150 Third seat member (third support part) 152 Pressing part 152b Boss section 154 Mounting screws 156 Side seat member (side support part) 158 Side pressing member 158b Boss section 158p Boss section 160 Side seat member (side support part) 162 Retaining bracket 164 Side pressing member 166 Reinforcement member 168 Second pressing member 168b Boss section 170 Third pressing member 170b Boss section B. Laser light (scanning light) CN primary transfer nip TN secondary transfer nip FN Fixing Nips D Manuscript S paper

Claims

1. An optical element having a first surface and a second surface on both sides in the thickness direction, A first support portion is provided, which is positioned on one end of the optical element in the longitudinal direction and supports the first or second surface, A first pressing member presses the optical element toward the first support portion, A second support portion is provided, which is positioned on the other end in the longitudinal direction and supports the portion of the optical element on the first surface on one end in the short direction. A third support portion is positioned on the other end in the longitudinal direction and supports the portion on the other end in the short direction of the first or second surface, The optical element is provided with a pressing portion that presses the optical element toward the second support portion and the third support portion, The pressing force of the pressing portion is set to be greater than the pressing force of the first pressing member. optical equipment.

2. The pressing force of the pressing portion is set to be greater than twice the pressing force of the first pressing member. The optical apparatus according to claim 1.

3. The third support portion is an adjustment member that supports the portion on the other end side in the short direction of the second surface and adjusts the orientation of the optical element by the displacement of the support position. The pressing portion is, A second pressing member presses the optical element toward the second support portion, The system includes a third pressing member that presses the optical element toward the adjustment member. The optical apparatus according to claim 1.

4. The pressing force of the second pressing member and the pressing force of the third pressing member are each set to be greater than the pressing force of the first pressing member. The optical apparatus according to claim 3.

5. In the longitudinal direction, the distance between the support point of the second support portion and the pressing point of the second pressing member is the same as the distance between the support point of the adjustment member and the pressing point of the third pressing member, and the bending moment due to the pressing force of the second pressing member with the support point of the second support portion as a fulcrum and the bending moment due to the pressing force of the third pressing member with the support point of the adjustment member as a fulcrum act in opposite directions. The optical apparatus according to claim 3.

6. The third support portion supports the portion on the other end side in the short direction of the first surface, The pressing portion presses the area on the second surface between the portion facing the support location of the second support portion and the portion facing the support location of the third support portion. The optical apparatus according to claim 1.

7. The third support portion supports the portion on the other end side in the short direction of the first surface, The pressing portion is, A second pressing member presses the optical element toward the second support portion, The optical element is pressed against the third support portion by a third pressing member, The optical apparatus according to claim 1.

8. The pressing force of the second pressing member and the pressing force of the third pressing member are each set to be greater than the pressing force of the first pressing member. The optical apparatus according to claim 7.

9. In the longitudinal direction, the distance between the support point of the second support portion and the pressing point of the second pressing member is the same as the distance between the support point of the third support portion and the pressing point of the third pressing member, and the bending moment due to the pressing force of the second pressing member with the support point of the second support portion as a fulcrum and the bending moment due to the pressing force of the third pressing member with the support point of the third support portion as a fulcrum act in opposite directions. The optical apparatus described in claim 7.

10. The first support portion supports the first surface, The optical apparatus according to claim 1.

11. A side support portion that contacts the side surface of one end in the shorter direction of the optical element, The system further comprises a side pressing member for pressing the optical element toward the side support portion. The optical apparatus according to claim 1.

12. The side support portion and the side pressing member are each positioned on one end in the longitudinal direction. The optical apparatus according to claim 11.

13. The system further includes a detachment restricting portion configured to be in a non-pressing state relative to the optical element, which restricts the in-plane movement of the optical element and thereby prevents the optical element from falling out of the second and third support portions. The optical apparatus according to claim 1.

14. The optical element further comprises a reinforcing member attached to the central part in the longitudinal direction of the optical element. The optical apparatus according to claim 1.

15. The pressing points of the first pressing member and the pressing points of the pressing part each make point contact with the optical element. The optical apparatus according to claim 1.

16. The pressing points of the first pressing member and the pressing points of the pressing portion are each formed in a spherical shape. The optical apparatus according to claim 15.

17. The support points of the first support portion, the support points of the second support portion, and the support points of the third support portion each make point contact with the optical element. The optical apparatus according to claim 1.

18. The support points of the first support portion, the support points of the second support portion, and the support points of the third support portion are each formed in a spherical shape. The optical apparatus according to claim 17.

19. The optical element is a mirror. The optical apparatus according to claim 1.

20. The aforementioned optical element is a mirror, The first surface is the reflective surface of the mirror. The optical apparatus according to claim 10.

21. A light source that emits scanning light, A polarizer that polarizes the scanning light emitted from the aforementioned light source, The optical device is arranged on the optical path of the scanning light polarized by the polarizer, and comprises the optical device according to any one of claims 1 to 20. Scanning optical device.

22. An image carrier for forming an image, The scanning optical apparatus according to claim 21 comprises scanning the image carrier with exposure to form an electrostatic latent image on the image carrier, Image forming apparatus.

Images