JP2022134995A - Optical device, optical writing device and image processing system - Google Patents

Abstract

To suppress unexpected vibration of an optical element by stabilizing a transfer function and a resonance frequency of a vibration system including the optical element.SOLUTION: An optical device comprises: an optical element 5 having a predetermined length in a first direction (an X direction), having a predetermined thickness in a second direction (a Y direction) orthogonal to the first direction, and having a predetermined width in a third direction (a Z direction) orthogonal to the first direction and the second direction, the predetermined length being longer than the predetermined thickness and the predetermined width; a first holding portion 52 that is in contact with both front and back surfaces of the optical element 5 positioned in the second direction and holds the optical element 5 while keeping pressing both the front and back surfaces; and a second holding portion 53 that is disposed so as to face two side faces of the optical element 5 positioned in the third direction at an interval wider than the predetermined width of the optical element 5 and that prevents the optical element 5 from moving in the third direction. The optical element 5 is held by the first holding portion 52 and the second holding portion 53 such that pressing force is not applied in the third direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to an optical device, an optical writing device, and an image processing device, and more particularly to a technique for suppressing vibration of optical elements such as mirrors in those devices.

2. Description of the Related Art Image processing apparatuses such as printers and MFPs (Multifunction Peripherals) that form images by electrophotography are equipped with an optical writing device. The optical writing device includes a light source, a deflector that deflects and scans the light emitted from the light source in the main scanning direction, and a scanning optical system that forms an image of the light deflected and scanned by the deflector on a predetermined image plane. ing. For example, the polarizer is composed of a polygon mirror, a galvanomirror, or the like. The scanning optical system includes optical elements such as fθ lenses and mirrors, and is configured to form an image of light guided from a polarizer on the surface of an image carrier or the like. When forming an image in an image processing apparatus, driving means such as a motor drives a polarizer or the like at a specific frequency. Therefore, the vibration generated by driving the polarizer or the like may be transmitted to the optical element. When the vibration is transmitted to the optical element, the optical element vibrates and displaces the imaging position with respect to the surface of the image carrier, resulting in deterioration of image quality.

Conventionally, in order to suppress the deterioration of image quality as described above, various ideas have been devised for the form of holding the optical element. For example, conventionally, as a method of fixing a long flat mirror to a housing, a method of suppressing the vibration of the mirror by pressing and holding the mirror at multiple points in a plurality of mutually orthogonal directions has been proposed (see, for example, Patent Documents 1). In this prior art, a long mirror is joined to both the front and back surfaces of the mirror in the thickness direction, and the mirror is pressed from one side to the other. The mirror is fixed by pressing the mirror.

By the way, if the incident frequency of the optical element (the frequency of vibration transmitted from the outside to the optical element) and the resonance frequency of the optical element overlap, the amplitude of the optical element becomes extremely large, and the optical element becomes unstable. It becomes difficult to suppress the vibration. Therefore, it is generally designed in advance so that the frequency for driving the polarizer and the resonance frequency of the optical element do not overlap.

However, in the case of a configuration in which a long optical element is pressed and held at multiple points in a plurality of directions perpendicular to each other, as in the above-described prior art, variations in processing and pressing force of the members that press and hold the mirror, and assembly errors may occur. Variations in the transfer function (response amplitude of the optical element to vibration from the outside) of the vibration system including the optical element (response amplitude of the optical element to external vibration) and the resonance frequency of the optical element occur due to changes in the intensity of the incoming vibration. For example, in a configuration in which both ends of a long optical element are pressed and held in a plurality of directions, even if the resonance frequency of the optical element is set to a predetermined frequency during design development, variations in processing and pressing of members that press and hold the optical element may occur. When the transfer function of the vibration system changes due to variations in pressure, assembly errors, changes in the intensity of incoming vibration, etc., the resonance frequency of the optical element shifts from the frequency set at the time of design development. Then, if the frequency of the incident vibration to the optical element overlaps with the resonance frequency of the shifted optical element, there is a problem that the vibration of the optical element becomes larger than the expected vibration.

Since the above-mentioned variation is a phenomenon with low reproducibility, it is difficult to grasp it at the early stage of development, and it is often discovered at the later stage of development. As a result, the number of man-hours required for development may be increased and anti-vibration parts may be unavoidably added, which is an obstacle to efficient and inexpensive product development.

JP 2009-276395 A

Accordingly, the present invention has been made to solve the above-described problems, and by stabilizing the transfer function and resonance frequency, suppresses unexpected vibrations of optical elements, increases development man-hours, and reduces vibration countermeasure equipment. It is an object of the present invention to provide an optical device, an optical writing device, and an image processing device capable of reducing additions.

In order to achieve the above object, the invention according to claim 1 is an optical device having a predetermined length in a first direction and a predetermined thickness in a second direction orthogonal to the first direction. an optical element having a predetermined width in a third direction orthogonal to the first direction and the second direction, the predetermined length being longer than the predetermined thickness and the predetermined width; a first holding part that contacts both front and back surfaces of the optical element positioned in the second direction at both ends of the optical element in the first direction and holds the optical element while pressing both the front and back surfaces; , arranged so as to face two side surfaces of the optical element positioned in the third direction at intervals wider than the predetermined width at both ends of the optical element in the first direction, and a second holding portion for preventing movement in a third direction, wherein the optical element is subjected to a pressing force in the third direction by the first holding portion and the second holding portion. The configuration is characterized in that it is held in a state in which it is not in use.

The invention according to claim 2 is the optical device according to claim 1, wherein the first holding part includes a first seating part that is bonded to one of the front and back surfaces of the optical element; a pressing portion disposed at a position facing the seating portion and bonded to the other surface of the front and back surfaces of the optical element to press the optical element toward the first seating portion. This is a characteristic configuration.

The invention according to claim 3 is the optical device according to claim 2, wherein the first seating portion is in point contact with one of the front and back surfaces of the optical element, and the pressing portion is the optical element. is in point contact with the other surface of the front and back surfaces of the.

The invention according to claim 4 is the optical device according to claim 2 or 3, wherein the first seating portion is formed of a steel ball, the pressing portion is formed of an elastic body, and the elastic force of the elastic body The configuration is characterized in that the optical element is pressed toward the first seating portion.

The invention according to claim 5 is the optical device according to any one of claims 2 to 4, characterized in that the first seating portions are arranged at a plurality of locations in the third direction.

The invention according to claim 6 is the optical device according to any one of claims 1 to 5, wherein the second holding parts are arranged so as to face each other at a position near the center of the side surface in the second direction. This is a characteristic configuration.

The invention according to claim 7 is the optical device according to any one of claims 1 to 6, wherein the first holding part and the second holding part are provided at the same position in the first direction of the optical element. It is a configuration characterized by

The invention according to claim 8 is the optical device according to any one of claims 1 to 7, wherein the thickness dimension in the second direction is the length in the first direction and the thickness in the third direction. is smaller than the width of the

The invention according to claim 9 is the optical device according to any one of claims 1 to 8, wherein the second holding part has a pair of protrusions that are capable of making point contact with the two side surfaces of the optical element. It is a configuration characterized by

The invention according to claim 10 is the optical device according to claim 9, wherein the tip position of at least one of the pair of protrusions is adjustable in the third direction. be.

The invention according to claim 11 is the optical device according to any one of claims 1 to 10, wherein the second holding part is a second seating part bonded to one of the two side surfaces of the optical element. and a drop-off preventing portion arranged at a position spaced apart from the other of the two side surfaces of the optical element by a predetermined distance.

According to a twelfth aspect of the invention, in the optical device according to the eleventh aspect, the second seating portion has higher rigidity than the drop-off preventing portion and is arranged at a position lower than the drop-off preventing portion. It is a configuration.

The invention according to claim 13 is the optical device according to any one of claims 1 to 12, in which two end faces positioned in the first direction are opposed to each other at a distance wider than the length of the optical element in the first direction. and a third holding portion arranged to prevent the optical element from moving in the first direction.

The invention according to claim 14 is the optical device according to any one of claims 1 to 13, characterized in that the shape of the optical element is a rectangular parallelepiped.

The invention according to claim 15 is the optical device according to any one of claims 1 to 15, wherein at least one of the front and back surfaces of the optical element is an optically functional surface.

The invention according to claim 16 is the optical device according to claim 14, wherein the optical functional surface of the optical element is a reflecting surface.

The invention according to claim 17 is an optical writing device, comprising: a light source; a polarizer for deflecting and scanning the light from the light source; and the optical device according to any one of 1 to 16, wherein an image is written by light projected from the optical device.

The invention according to claim 18 is an image processing apparatus comprising the optical device according to any one of claims 1 to 16, wherein an image is read or an image is written by light projected from the optical device. It is a configuration characterized by

According to the present invention, it is possible to suppress variations in the transfer function and resonance frequency of a vibration system including an optical element to be small and to stabilize it, and to suppress a phenomenon in which the optical element vibrates at an unexpected frequency. . Therefore, since it becomes unnecessary to take measures against vibrations of the optical element in the latter stage of development, it becomes possible to reduce the increase in development man-hours and the addition of parts for measures against vibrations.

1 is a diagram conceptually showing the basic configuration of an optical device; FIG. It is a figure which shows the example of the holding|maintenance aspect which hold|maintains the both-end vicinity position of an optical element. FIG. 5 is a diagram conceptually showing a comparative example of an optical device; FIG. 10 is a diagram showing an example of change in transfer function when a comparative example is employed; FIG. 5 is a diagram showing an example of change in transfer function when the basic configuration of the optical device is adopted; It is a figure which shows an example of the internal structure of an image processing apparatus. It is a figure which shows the structural example of an optical writing apparatus. FIG. 4 is a perspective view showing a mode of holding a mirror in an optical device; It is the front view which looked at the optical apparatus from the polarizer side. It is a perspective view which expands and shows a holding|maintenance part. FIG. 4 is a cross-sectional view showing one form of a holding portion; It is the enlarged view which looked at the edge part vicinity of the mirror from the front side. FIG. 10 is a diagram showing a preferred installation position of the second seat; 1 is an assembly diagram of an optical device; FIG. FIG. 11 is a cross-sectional view showing another form of the holding portion; FIG. 11 is a cross-sectional view showing still another form of the holding portion; FIG. 11 is a cross-sectional view showing still another form of the holding portion;

Preferred embodiments of the present invention will be described in detail below with reference to the drawings. Elements common to each other in the embodiments described below are denoted by the same reference numerals, and redundant description thereof will be omitted.

(Basic configuration of optical device)
First, the basic configuration of the optical device according to the embodiment of the present invention will be described. FIG. 1 is a diagram conceptually showing the basic configuration of an optical device. This optical device includes a holder 51 for holding both ends of an optical element 5 composed of a long plate-shaped (rectangular parallelepiped) mirror or the like. The optical element 5 has a predetermined length in a first direction (X direction), a predetermined thickness in a second direction (Y direction) orthogonal to the first direction, and further has a predetermined thickness in the first direction (X direction). It has a predetermined width in a third direction (Z direction) orthogonal to each of the second directions. The length of the optical element 5 in the first direction is longer than the thickness in the second direction and the width in the third direction. The holding portion 51 is configured to hold both ends of the optical element 5 in the first direction (X direction), which is the longitudinal direction. The holding portion 51 includes a first holding portion 52 arranged along the second direction of the optical element 5 and a second holding portion 53 arranged along the third direction of the optical element 5. there is

The first holding portion 52 has two members 52 a and 52 b arranged to face each other with the optical element 5 interposed therebetween in the second direction of the optical element 5 . These two members 52a and 52b are in contact with two surfaces (front and back surfaces) positioned in the second direction of the optical element 5, respectively. Both front and back surfaces of the optical element 5 are perpendicular to the second direction. For example, the two members 52a and 52b are at the same position on the XZ plane, one member 52a is in point contact with the surface of the optical element 5, and the other member 52b is in point contact with the back surface of the optical element 5. FIG. A pressing force F is applied to at least one member 52a of the two members 52a and 52b. This pressing force F acts in a direction from one member 52a toward the other member 52b. Therefore, the first holding portion 52 holds the front and back surfaces of the optical element 5 by the pressing force F in a state in which the two members 52a and 52b sandwich the front and back surfaces.

The second holding portion 53 has two members 53 a and 53 b arranged to face each other with the optical element 5 interposed therebetween in the third direction of the optical element 5 . These two members 53a and 53b are arranged at an interval wider than the width dimension of the optical element 5 in the third direction. In addition, the two members 53a and 53b are arranged so as to face two side surfaces (both side surfaces) located in the third direction of the optical element 5 . Note that the two side surfaces of the optical element 5 are orthogonal to the third direction. For example, one member 53 a of the two members 53 a and 53 b is in point contact with one side surface of the optical element 5 . On the other hand, the other member 53b is located at a predetermined distance from the other side surface of the optical element 5. As shown in FIG. Moreover, the pressing force unlike the first holding portion 52 does not act on the two members 53a and 53b. Therefore, the second holding portion 53 does not hold the optical element 5 in a sandwiched state in the third direction. In other words, the second holding portion 53 restricts movement of the optical element 5 in the third direction. That is, when external vibration is transmitted to the optical element 5 , the second holding portion 53 moves the optical element 5 in the third direction, and the second holding portion 53 shifts from the state held by the first holding portion 52 . It is provided as a fall prevention member for preventing the optical element 5 from being detached.

As described above, the optical device of the present embodiment is basically configured to hold both ends of the optical element 5 elongated in the first direction, and the optical element 5 in the second direction (thickness direction), the first holding portion 52 holds the optical element 5 in a state of sandwiching it with a pressing force F, and the second holding portion 53 applies a pressing force to the optical element 5 in the third direction (width direction) of the optical element 5. The optical element 5 is held so as not to be detached in a non-acting state. With such a holding mode, the optical device can stabilize the transfer function of the vibration system including the optical element 5 and the resonance frequency of the optical element 5 .

Next, stabilization of the transfer function of the vibration system including the optical element 5 and the resonance frequency of the optical element 5 will be described. FIG. 2 is a diagram showing an example of a holding mode in which both ends of the optical element 5 are held. FIG. 2A illustrates a case where both ends of the optical element 5 are simply supported. Here, the simple support means a support mode in which support members 6, 6 are arranged on the back side of both ends of the optical element 5, and the optical element 5 is simply placed on these support members 6, 6, for example. In this case, both ends of the optical element 5 are not fixed. In addition, since the thickness dimension of the optical element 5 in the second direction (Y direction) is smaller than the dimension in other directions, when vibration is transmitted from the outside, the vibration in the second direction remarkably appears. Therefore, when external vibration is transmitted to the optical element 5, the optical element 5 vibrates as shown in FIG. 2(b). That is, the optical element 5 vibrates over its entire longitudinal direction (first direction). At this time, the optical element 5 is not displaced in the second direction at the position supported by the supporting members 6,6. However, when the central portion of the optical element 5 is greatly bent, the optical element 5 is displaced in the first direction at the position supported by the supporting members 6 and 6 .

FIG. 2(c) illustrates a case where both ends of the optical element 5 are completely fixed. Here, complete fixation means a support mode in which the both ends of the optical element 5 are fixed to the rigid body 7 so that both the front and back surfaces of the optical element 5 are not moved at all. In this case, since both ends of the optical element 5 are completely fixed, when external vibration is transmitted to the optical element 5, the optical element 5 vibrates as shown in FIG. 2(d). In other words, the optical element 5 comes to vibrate only at the central portion, excluding both ends. At this time, since both ends of the optical element 5 are completely fixed, they are not displaced in either the first direction or the second direction.

On the other hand, as shown in FIG. 1 , the first holding portions 52 hold the optical element 5 in a state of sandwiching the optical element 5 with a pressing force F with respect to the second direction (thickness direction) of the optical element 5 . 3 direction (width direction), the second holding portion 53 holds the optical element 5 in a state in which no pressing force is applied to the optical element 5 so that the optical element 5 does not come off. When applied, the central portion of the optical element 5 vibrates in the second direction. When the intensity of incoming vibration with respect to the optical element 5 is relatively weak, the first holding section 52 holds the vicinity of both ends of the optical element 5 so as not to vibrate, so that the above-described state is almost completely fixed. However, when the intensity of the incident vibration to the optical element 5 is relatively strong, the optical element 5 tries to vibrate against the pressing force F of the first holding portion 52, resulting in a state close to the above-described simple support.

Here, as a comparative example different from the basic configuration described above, the second holding portion 53 applies a pressing force F to sandwich the optical element 5 not only in the second direction but also in the third direction. An example of keeping the status is explained. FIG. 3 is a diagram conceptually showing a comparative example of the optical device. In this optical device, unlike the basic configuration described above, the two members 53a and 53b provided as the second holding portion 53 are arranged in relation to the third direction of the optical element 5 so as to form two surfaces perpendicular to the third direction. (both sides) are in contact with each other. A pressing force F is applied to at least one member 53b of the two members 53a and 53b. Therefore, the second holding portion 53 holds both side surfaces of the optical element 5 with the two members 53a and 53b by the pressing force F thereof.

In a holding mode such as the comparative example, when external vibration with a relatively weak input strength acts on the optical element 5, the vicinity of both ends of the optical element 5 is in a state close to being completely fixed. The contact position with the element 5 does not change, and static friction is generated between the second holding portion 53 and the optical element 5 . On the other hand, when the optical element 5 is subjected to external vibration with a relatively high input intensity, the vicinity of both ends of the optical element 5 changes to a state close to simple support. A positional slip occurs, and dynamic friction occurs between the second holding portion 53 and the optical element 5 .

When dynamic friction occurs between the second holding portion 53 and the optical element 5 , it affects vibration of the optical element 5 . In particular, in the case of the holding mode as in the comparative example, the frictional force acting between the second holding portion 53 and the optical element 5 increases in proportion to the pressing force F applied by the second holding portion 53. The influence on the vibration of the optical element 5 is increased. As a result, the transfer function of the vibration system including the optical element 5 and the resonance frequency of the optical element 5 change greatly according to the intensity of the incident vibration that strikes the optical element 5 .

FIG. 4 is a diagram showing an example of change in transfer function when the intensity of incoming vibration is changed in a holding mode such as a comparative example. As shown in FIG. 4, in the comparative example, the resonance frequency of the optical element 5 gradually changes to a lower frequency range as the incoming vibration intensity increases in the order of I1, I2, I3, I4, and I5. In particular, if the optical element 5 is pressed and held not only in the second direction but also in the third direction as in the comparative example, the amount of change in the resonance frequency with respect to the change in the intensity of the incoming vibration increases due to the effect of dynamic friction. end up

On the other hand, as in the basic configuration described above, the first holding portion 52 holds the optical element 5 in a state of sandwiching the optical element 5 with a pressing force F in the second direction (thickness direction) of the optical element 5 . With respect to the third direction (width direction) of , when the second holding portion 53 holds the optical element 5 so as not to detach while the pressing force is not applied to the optical element 5 , Even if the input vibration intensity is changed, the amount of change in the transfer function and the resonance frequency can be kept small.

FIG. 5 is a diagram showing an example of change in transfer function when the intensity of incoming vibration is changed in the basic configuration of the optical device described above. As shown in FIG. 5, in the basic configuration, as the intensity of incoming vibration increases in the order of I1, I2, I3, I4, and I5, the resonance frequency of the optical element 5 gradually changes to a lower frequency range. It can be seen that the amount of change is small when compared with the comparative example. In other words, in the basic configuration, it is possible to limit the region in which the resonance frequency of the optical element 5 changes to a narrow region, and stabilize the transfer function and resonance frequency.

Therefore, by adopting the basic configuration described above, it is possible to set the frequency for driving the polarizer or the like from the initial stage of development to a frequency band that does not overlap with the resonance frequency of the optical element 5, reducing development man-hours. It is possible to reduce the increase and the addition of anti-vibration fixtures. A specific embodiment employing the basic configuration described above will be described below.

(First embodiment)
FIG. 6 is a diagram showing the internal structure of the image processing device 1 according to one embodiment of the present invention. The image processing apparatus 1 is an apparatus configured by an MFP (Multifunction Peripheral) or the like and capable of forming an image by electrophotography. This image processing apparatus 1 has a printer section 2 in the lower part of the apparatus main body and a scanner part 3 in the upper part of the apparatus main body. The image processing apparatus 1 also has an operation panel 4 that can be operated by a user on the upper front side of the main body of the apparatus.

The printer section 2 includes a paper feed tray 10 , a transport path 11 , a fixing section 16 , an image forming section 20 and an optical writing device 30 . The printer unit 2 picks up one sheet from a sheet bundle 9 accommodated in a paper feed tray 10 with a pickup roller 12 and a paper feed roller 13 and feeds the sheet toward a transport path 11 . The sent sheet is conveyed along the conveying path 11 in the direction of the arrow F1. A timing roller 14 , a secondary transfer roller 15 and a fixing section 16 are arranged on the transport path 11 . The skew of the sheet conveyed along the conveying path 11 is corrected when the leading edge of the sheet reaches the timing roller 14 . After that, the timing roller 14 is driven in synchronization with the timing at which the toner image formed in the image forming section 20 reaches the position of the secondary transfer roller 15 , and the sheet is sent out toward the secondary transfer roller 15 . Then, the toner image is transferred when the sheet passes the position of the secondary transfer roller 15 . After that, the sheet is guided to the fixing section 16, and is subjected to heat treatment and pressure treatment while passing through the nip portion between the fixing roller 16a and the pressure roller 16b, thereby fixing the toner image. The sheet on which the toner image has been fixed is discharged from a paper discharge port 17 to a paper discharge tray 18 provided at the top of the printer section 2 .

The image forming unit 20 includes a pair of rollers 21 and 22, an endless belt-shaped intermediate transfer belt 23 stretched over the rollers 21 and 22, a plurality of developing units 24 provided below the intermediate transfer belt 23, and an intermediate transfer belt 23. A plurality of primary transfer rollers 26 are provided so as to face each developing unit 24 with the belt 23 interposed therebetween. One roller 22 of the pair of rollers 21 and 22 is a drive roller and is in contact with the secondary transfer roller 15 via the intermediate transfer belt 23 . The other roller 21 is a driven roller. The intermediate transfer belt 23 stretched over the rollers 21 and 22 circulates in the direction of the arrow F2 as the rollers 21 and 22 are driven.

A plurality of developing units 24 are units that form toner images corresponding to respective colors of Y (yellow), M (magenta), C (cyan), and K (black) and primarily transfer them onto the intermediate transfer belt 23 . For example, the developing unit 24Y forming a Y toner image, the developing unit 24M forming an M toner image, and the developing units 24C and 24K forming a C toner image are arranged in order from the upstream side in the movement direction F2 of the intermediate transfer belt 23. A developing unit 24K for forming a toner image of . Toner bottles 28Y, 28M, 28C and 28K are connected to these developer units 24Y, 24M, 24C and 24K, and toners of respective colors are supplied from the toner bottles 28Y, 28M, 28C and 28K, respectively.

The developing unit 24 is provided with an image carrier 25 configured by a photosensitive drum or the like. The image carrier 25 is exposed by an optical writing device 30 to form an electrostatic latent image on its surface. The developing unit 24 attaches toner to the electrostatic latent image to visualize the electrostatic latent image and form a toner image. The toner image formed on the image carrier 25 is primarily transferred to the surface of the intermediate transfer belt 23 when passing through a position facing the primary transfer roller 26 . After that, the toner image moves toward the position of the secondary transfer roller 15 as the intermediate transfer belt 23 circulates. Secondarily transferred to the surface.

Based on the image data to be printed, the optical writing device 30 irradiates the surface of the image carrier 25 with light 27 from a position below the developing unit 24 to form an image on the surface of the image carrier 25 . expose. As a result, an electrostatic latent image corresponding to the image data is formed on the surface of the image carrier 25 . A configuration example of the optical writing device 30 will be described later.

The scanner unit 3 includes an image reading device 40 that optically reads an image of a document placed on a platen glass 41 provided on the upper surface. The scanner section 3 also has an opening/closing cover 42 above the platen glass 41 .

The image reading device 40 includes two scanning members 43 a and 43 b, an optical system 48 and a light receiving element 49 . The scanning member 43a is arranged on the lower surface side of the platen glass 41, is driven by a driving means such as a motor (not shown), and can reciprocate in the arrow F3 direction (sub-scanning direction). The scanning member 43a includes a light source 44 for illuminating the surface (reading surface) of the document placed on the platen glass 41, and a mirror 45 for reflecting light reflected from the surface of the document, and illuminates the surface of the document. It is possible to move in the sub-scanning direction while moving. Like the scanning member 43a, the scanning member 43b is driven by a driving means such as a motor (not shown), and can reciprocate in the arrow F3 direction (sub-scanning direction). The scanning member 43b has two mirrors 46 and 47 for reflecting the light reflected by the mirror 45 of the scanning member 43a toward the optical system 48 and the light receiving element 49. As shown in FIG. The scanning member 43b moves in the direction of the arrow F3 along with the movement of the scanning member 43a so that the light path length of the light reflected by the surface of the original to the light receiving element 49 is always constant. The optical system 48 is an optical system that forms an image on the light receiving element 49 from the light reflected by the surface of the document. The light receiving element 49 has a plurality of pixels arranged in the main scanning direction orthogonal to the sub-scanning direction, and generates an electric signal according to the amount of light imaged on each pixel by the optical system 48 . The image reading device 40 moves the two scanning members 43a and 43b in the sub-scanning direction while accumulating electrical signals for each line in the main scanning direction generated by the light receiving element 49 in the sub-scanning direction. , to generate image data corresponding to the image of the document.

In the image processing apparatus 1 configured as described above, the optical device having the basic configuration described above is mounted, for example, in the optical writing device 30 . FIG. 7 is a diagram showing a configuration example of the optical writing device 30. As shown in FIG. The optical writing device 30 comprises a light source 31 , a polarizer 32 and an optical device 33 . The optical writing device 30 is equipped with four sets of units each having a light source 31, a polarizer 32, and an optical device 33 in order to write images corresponding to the colors Y, M, C, and K individually. I don't mind.

The light source 31 is a light source that emits light (for example, laser light) for exposing the image carrier 25 . The polarizer 32 is for deflecting and scanning the light from the light source 31 and includes a polygon mirror 36 , a motor 37 and an optical system 35 . Polygon mirror 36 is a rotating polyhedral mirror. The motor 37 is driving means for rotating the polygon mirror 36 in a predetermined rotation direction (R direction). The optical system 35 is composed of, for example, an fθ lens.

Light L1 emitted from the light source 31 is applied to a predetermined position of the rotating polygon mirror 36, and is converted into light L2 that is deflected and scanned by the rotation of the polygon mirror 36. FIG. The light L2 is converted by the optical system 35 into light L3 that scans at a constant speed in the main scanning direction (X direction).

The optical device 33 is arranged in the traveling direction of the light L3 deflected and scanned by the polarizer 32 and converts the light L3 into the light L4 directed toward the image carrier 25 . The optical device 33 has an elongated mirror 38 as an optical element 5 that converts the light L3 into the light L4. That is, the optical element 5 in this embodiment has one of the front and back surfaces of the flat elongated member (the front surface in this embodiment) as an optical functional surface, and the optical functional surface is an element formed as a reflective surface. (mirror 38). The mirror 38 is inclined at a predetermined angle with respect to the traveling direction of the light L3, and projects the light L4 onto the surface of the image carrier 25 positioned above the optical writing device 30 to write an electrostatic latent image. can be done.

FIG. 8 is a perspective view showing a mode of holding the mirror 38 in the optical device 33. As shown in FIG. The mirror 38 is an elongated optical element 5 having a predetermined length in the first direction (X direction), and has, for example, a cubic shape. Also, the mirror 38 has a predetermined thickness in a second direction (Y direction) orthogonal to the first direction, and a third direction (Z direction) orthogonal to each of the first direction and the second direction. direction) has a predetermined width. The mirror 38 has an optically functional surface (reflecting surface) on one of the front and back surfaces positioned in the second direction (Y direction). The optical device 33 has a housing 50 that holds the mirror 38 in a predetermined posture. The housing 50 includes holding portions 51 that hold both ends 38a and 38b of the mirror 38 in the longitudinal direction (first direction). The holding portion 51 includes a holding portion 51a provided on one end side of the mirror 38 and a holding portion 51b provided on the other end side.

FIG. 9 is a front view of the optical device 33 as seen from the polarizer 32 side. The holding portion 51 includes a first holding portion 52 , a second holding portion 53 and a third holding portion 54 . That is, the holding portion 51 further includes a third holding portion 54 in addition to the first holding portion 52 and the second holding portion 53 described as the basic configuration. The first holding part 52 holds both ends of the mirror 38 by sandwiching and pressing the front and back surfaces of the mirror 38 in the second direction of the mirror 38 . That is, the holding portion 51 fixes both ends of the mirror 38 to the housing 50 by the first holding portion 52 . The second holding portion 53 is provided as an anti-falling member that prevents the mirror 38 from being disengaged from the state held by the first holding portion 52 due to movement in the third direction. That is, the second holding portion 53 is for restricting the movement of the mirror 38 in the second direction. The third holding portion 54 is provided as a fall prevention member that prevents the mirror 38 from moving in the first direction and leaving the state held by the first holding portion 52 . That is, the third holding portion 54 is for restricting the movement of the mirror 38 in the first direction.

FIG. 10 is an enlarged perspective view of the holding portion 51 (51a). FIG. 11 is a cross-sectional view of the holding portion 51 (51a), showing the AA cross section in FIG. 10 and 11 illustrate one holding portion 51a, the other holding portion 51b has the same configuration.

As shown in FIG. 11, the housing 50 has inclined surfaces 61 and 65 at both ends corresponding to the arrangement angle of the mirror 38 . The inclined surface 61 is parallel to the front surface 381 and the back surface 382 of the mirror 38 located in the second direction (Y direction), and the inclined surface 65 is parallel to the two surfaces located in the third direction (Z direction) of the mirror 38. It is parallel to the side surfaces 383,384. The inclined surface 61 is provided with a first seating portion 62 provided substantially in the center of the back surface 382 in the third direction of the mirror 38 . In addition, the inclined surface 65 is provided with a second seating portion 66 provided substantially in the center of one side surface 383 in the second direction of the mirror 38 .

The first seating portion 62 supports the mirror 38 while being in contact with the rear surface 382 of the mirror 38 . For example, the first seating portion 62 is formed by providing a concave portion 63 in the inclined surface 61 and fitting a highly rigid stainless steel ball 64 into the concave portion 63 . Since the depth of the recessed portion 63 is smaller than the diameter of the steel ball 64 , when the steel ball 64 is fitted into the recessed portion 63 , a portion of the steel ball 64 forms a protrusion projecting from the surface of the inclined surface 61 . do. The rear surface 382 of the mirror 38 is supported in contact with the protrusion formed by the steel ball 64 at one point. Such a first seating portion 62 forms part of the first holding portion 52 (member 52b shown in FIG. 1).

The second seating portion 66 supports the mirror 38 in contact with one side surface 383 of the mirror 38 . For example, the second seat portion 66 is formed by providing a recess 67 in the inclined surface 65 and fitting a high-rigidity steel ball 68 into the recess 67 in the same manner as the first seat portion 62 . Since the depth of the recessed portion 67 is smaller than the diameter of the steel ball 68 , when the steel ball 68 is fitted into the recessed portion 67 , a portion of the steel ball 68 forms a protrusion projecting from the surface of the inclined surface 65 . do. One side surface 383 of the mirror 38 is supported in contact with the projection of the steel ball 68 at one point. Such a second seat portion 66 forms part of the second holding portion 53 (the member 53a shown in FIG. 1).

Holding members 70 are attached to the housing 50 so as to correspond to both ends of the mirror 38 . The holding member 70 is a leaf spring-shaped member made of resin, for example. The holding member 70 includes a flat mounting portion 71 attached to the housing 50 and a pressing portion extending from the mounting portion 71 and contacting the surface 381 of the mirror 38 to press the mirror 38 toward the inclined surface 61 . 73, a first fall prevention portion 75 extending from the mounting portion 71 and arranged parallel to the other side surface 384 of the mirror 38 at a predetermined distance from the other side surface 384; The second mirror 38 extends from the side surface of the drop-off preventing portion 75 to the end face 385 in the longitudinal direction (X direction) of the mirror 38 and is arranged in parallel with the end face 385 at a predetermined distance from the end face 385 of the mirror 38 . 2 drop-off prevention portions 81 are provided.

For example, the mounting portion 71 of the holding member 70 is positioned at a predetermined position of the housing 50 by pins 58 and 59 provided on the housing 50 and fixed to the positioned position by screws 57 .

The pressing portion 73 is formed of an elastic body having a substantially L-shaped leaf spring structure, and has one end connected to the mounting portion 71 and the other end having a flat plate portion parallel to the surface 381 of the mirror 38 . The pressing portion 73 has a projecting portion 74 projecting in a hemispherical shape toward the surface 381 of the mirror 38 at a predetermined position on a flat plate portion parallel to the surface 381 of the mirror 38 . The protrusion 74 is at the same position as the first seat 62 provided on the inclined surface 61 of the housing 50 in the XZ plane. The pressing portion 73 pushes the mirror 38 to the first seating portion 62 by the elastic force (biasing force) of the elastic body of the plate spring structure in a state where the tip of the protrusion 74 is in contact with the surface 381 of the mirror 38 at one point. It can be installed in a state of being pushed toward it. That is, the mirror 38 is held in a state of being pressed in the second direction (Y direction) of the mirror 38 by two members, the pressing portion 73 of the holding member 70 and the first seating portion 62 provided in the housing 50 . A first holding portion 52 is formed.

The first drop-off preventing portion 75 may be formed so as to extend from the mounting portion 71 integrally with the pressing portion 73 as described above, or may be formed independently of the pressing portion 73 and attached to the mounting portion. It may be formed so as to extend from 71 .

The first drop-out preventing portion 75 has a flat plate portion parallel to one side surface 384 of the mirror 38, and a protrusion 76 projecting in a hemispherical shape toward the side surface 384 of the mirror 38 at a predetermined position of the flat plate portion. have. As shown in FIG. 11, the tip of the projection 76 does not abut on the side surface 384 of the mirror 38 and is arranged with a certain gap between it and the side surface 384 of the mirror 38 . The protrusion 76 is located at the same position as the second seating portion 66 provided on the inclined surface 65 of the housing 50 in the XY plane. Such a first drop-off preventing portion 75 is for preventing the mirror 38 from moving in the third direction (Z direction) and dropping off when external vibration is transmitted. be. In other words, the mirror 38 is moved in the third direction (Z direction) by the two members, the first drop-off preventing portion 75 and the second seat portion 66 provided in the housing 50, so that the first holding portion 52 is moved. A second holding portion 53 is formed to prevent the holding state from being detached.

The second drop-off preventing portion 81 is connected to the flat plate portion of the first drop-off preventing portion 75 as described above and has a flat plate portion parallel to the end face 385 of the mirror 38 . FIG. 12 is an enlarged view of the vicinity of the end of the mirror 38 viewed from the front side. The flat plate portion of the second drop-out preventing portion 81 is located at a predetermined distance from the end surface 385 of the mirror 38 . In addition, the second drop-out preventing portion 81 has a projecting portion 82 projecting in a hemispherical shape toward the end surface 385 of the mirror 38 at a predetermined position of the flat plate portion. The protruding portion 82 is arranged so that its tip is not in contact with the end face 385 of the mirror 38 and has a certain gap between it and the end face 385 of the mirror 38 . Such a second drop-off preventing portion 81 is for preventing the mirror 38 from moving in the first direction (X direction) and dropping off when external vibration is transmitted. be. The third holding portion 54 is formed by arranging the second anti-falling portion 81 close to both longitudinal end surfaces of the mirror 38 .

As described above, the holding portion 51 of the optical device 33 applies pressure only in the second direction (Y direction), which is the thickness direction of the mirror 38, by the first holding portion 52, so that both the front and back surfaces of the mirror 38 are supported. It is held in a sandwiched state and fixed to the housing 50.例文帳に追加In other words, the second holding portion 53 and the third holding portion 54 of the holding portion 51 relate to the first direction (X direction) that is the longitudinal direction of the mirror 38 and the third direction (Z direction) that is the width direction of the mirror 38, The mirror 38 is held so as not to drop off from the holding portion 51 without applying a pressing force to the mirror 38 . Therefore, the position where the mirror 38 contacts the first holding portion 52 becomes a fixed point, and if vibration from the outside is transmitted to the mirror 38, the mirror 38 vibrates around the fixed point as a fulcrum.

Here, since the second holding portion 53 in this embodiment supports the mirror 38 arranged in an inclined state, the second seating portion 66 is arranged at a lower position in the direction of gravity than the first fall prevention portion 75. , and the second seating portion 66 is joined to one side surface 383 of the mirror 38 . Therefore, when vibration from the outside is transmitted to the mirror 38 and the mirror 38 vibrates, a slip occurs between the second seating portion 66 and the side surface 383 of the mirror 38, causing the second seating portion 66 and the side surface 383 of the mirror 38 to slide. can change from static friction to dynamic friction. In order to prevent this, the second seating portion 66 is preferably arranged so as to contact the center of the side surface 383 of the mirror 38 in the thickness direction (second direction) of the mirror 38 .

FIG. 13 shows a preferred installation position of the second seat 66. As shown in FIG. FIG. 13(a) shows a state in which the mirror 38 vibrates so as to protrude upward with the position held by the first holding portion 52 as a fixed point. In the state shown in FIG. 13A, tensile deformation occurs on the upper side of the mirror 38 (the side closer to the protrusion 74 in the second direction (Y direction)), and the lower side of the mirror 38 (the second direction ( Compressive deformation occurs on the side near the first seating portion 62 in the Y direction). Next, FIG. 13(b) shows a state in which the mirror 38 vibrates so as to project downward with the position held by the first holding portion 52 as a fixed point. In the state shown in FIG. 13B, the upper side of the mirror 38 undergoes compression deformation, and the lower side of the mirror 38 undergoes tensile deformation. When the mirror 38 vibrates with the position held by the first holding portion 52 as a fulcrum, the amount of displacement due to tensile deformation or compressive deformation becomes small at a point on the line 387 at the center of the mirror 38 . In particular, the central position P1, which is the intersection of the line connecting the two points held by the first holding portion 52 and the central line 387, has the least deformation due to tensile deformation and compressive deformation, and the amount of displacement is negligible. Moderately small. Therefore, by bringing the second seat portion 66 into contact with the central position P1 of the mirror 38, the second seat portion 66 can support a position that does not move even when the mirror 38 vibrates. , the friction with the mirror 38 can be suppressed from changing from static friction to dynamic friction. Therefore, even if the intensity of the incoming vibration to the mirror 38 changes, it is possible to stabilize the transfer function of the vibration system including the mirror 38 and the resonance frequency of the mirror 38 .

Moreover, when the mirror 38 moves in the third direction (Z direction) and comes into contact with the side surface 384 of the mirror 38, the protrusion 76 of the first drop-off prevention portion 75 facing the second seating portion 66 also It is preferable to make contact with the central position P1 of the mirror 38 . Therefore, it is preferable that the protrusion 76 of the first drop-off prevention portion 75 is also arranged at the center position P1 of the mirror 38 in the second direction (Y direction), like the second seating portion 66 .

FIG. 14 is an assembly diagram of the optical device 33. As shown in FIG. A first seat portion 62 and a second seat portion 66 are provided in advance on the inclined surfaces 61 and 65 provided at both ends of the housing 50 . That is, the first seat portion 62 and the second seat portion 66 are installed by fitting the steel balls 64 and 68 into the recesses 63 and 67 provided on the inclined surfaces 61 and 65, respectively. The mirror 38 rests on the first 62 and second 66 seats. At this time, the mirror 38 is supported by the steel ball 68 at one point near the center of one side surface 383 and by the steel ball 64 at one point near the center of the back surface 382 . Since the steel balls 64 and 68 are highly rigid members, the holding position of the mirror 38 can be stabilized. Once the mirror 38 is placed on the first seat 62 and the second seat 66, the retaining members 70 are then attached to the ends of the housing 50. As shown in FIG.

The housing 50 has two pins 58 and 59 and a screw hole 57a at the portion where the holding member 70 is attached. On the other hand, the mounting portion 71 of the holding member 70 is provided with holes 71a and 71b into which the two pins 58 and 59 are fitted and a hole 71c through which the screw 57 is inserted. Of the two holes 71a and 71b, one hole 71a is formed as an elongated hole having a predetermined length in the X direction. By fitting the pins 58 and 59 into the two holes 71a and 71b, respectively, the holding member 70 is positioned at a predetermined position at the end of the housing 50. As shown in FIG. In this state, by adjusting the position of the mirror 38 in the first direction (X direction), the positions of both longitudinal end surfaces 385 and 386 of the mirror 38 with respect to the second drop-out preventing portion 81 can be adjusted. The holding member 70 is fixed at a predetermined position of the housing 50 by inserting the screw 57 into the hole 71c of the mounting portion 71 and screwing it into the screw hole 57a. As a result, the pressing portion 73 of the holding member 70 contacts the surface 381 of the mirror 38 with the protrusion 74 and presses the mirror 38 toward the first seating portion 62 . In addition, the first drop-off preventing portion 75 of the holding member 70 holds the protrusion 76 at a position separated from the side surface 384 of the mirror 38 by a predetermined distance, and presses the mirror 38 with a pressing force in the third direction (Z direction). will not work.

The pressing force of the pressing portion 73 can be adjusted by adjusting the tightening degree of the screw 57 to the screw hole 57a. However, even if the pressing force by the pressing portion 73 becomes relatively strong, since the rear surface 382 of the mirror 38 is supported by the highly rigid steel ball 64, the mirror 38 can be moved to a predetermined position without being distorted. can be held in place. Therefore, by attaching the holding member 70 to the housing 50 as described above, it is possible to easily and precisely adjust the positions of the first drop-off preventing portion 75 and the second drop-off preventing portion 81 with respect to the mirror 38. is. Therefore, the work of assembling the mirror 38 to the housing 50 can be efficiently performed.

Therefore, the optical device 33 of the present embodiment can stabilize the transfer function of the vibration system including the mirror 38 and the resonance frequency of the mirror 38, and improve work efficiency when assembling the mirror 38 to the housing 50. It also has the advantage of being able to

(Second embodiment)
Next, FIG. 15 is a cross-sectional view showing another form of the holding portion 51. As shown in FIG. The holding portion 51 shown in FIG. 15 has a projection 83 formed on an inclined surface 61 of the housing 50 that constitutes a first seating portion 62 , and a projection 84 formed on an inclined surface 65 of the housing 50 that constitutes a first seating portion 62 . 2 seating portions 66 are configured. For example, the protrusions 83 and 84 are formed in a conical or pyramidal shape, and support the mirror 38 with their tips contacting the rear surface 382 or the side surface 383 of the mirror 38 . Since these projections 83, 84 are integrally formed with the inclined surfaces 61, 65 when the housing 50 is formed, there is no need to fit the steel balls 64, 68 as in the first embodiment. Therefore, there is an advantage that the assembly work of the optical device 33 can be performed more efficiently.

FIG. 15 shows an example in which the protruding portion 74 provided on the pressing portion 73 protrudes in a hemispherical shape as in the first embodiment, but the present invention is not limited to this. That is, the projecting portion 74 may have a conical or pyramidal projecting shape. The same applies to the projecting portion 76 provided on the first drop-off preventing portion 75, and the projecting portion 76 may have a conical or pyramidal projecting shape.

Other points in this embodiment are the same as those described in the first embodiment.

(Third Embodiment)
Next, FIG. 16 is a cross-sectional view showing still another form of the holding portion 51. As shown in FIG. As shown in FIG. 16(a), the holding portion 51 has concave portions 63 and 67 formed in inclined surfaces 61 and 65 of the housing 50 as circular screw holes 63a and 67a. Projecting members 85 and 86 are mounted in the screw holes 63a and 37a. The protruding members 85 and 86 are formed in a hemispherical shape on the distal end side, and a male screw 87 is formed on the proximal end side to be screwed into the screw holes 63a and 67a. The protruding members 85 and 86 are attached in such a manner that the hemispherical tip portions protrude from the surfaces of the inclined surfaces 61 and 65 by screwing the male screws 87 into the screw holes 63a and 67a.

FIG. 16(b) shows a state in which the projecting members 85 and 86 are attached to the inclined surfaces 61 and 65 of the housing 50, respectively. The first seating portion 62 in the present embodiment is constructed by fitting a projection member 85 into a screw hole 63 a provided in the inclined surface 61 . Similarly, the second seat portion 66 is configured by fitting a projection member 86 into a screw hole 67 a provided in the inclined surface 65 . The first seat portion 62 and the second seat portion 66 having such a configuration can be formed into hemispherical distal ends protruding from the inclined surfaces 61 and 65 by adjusting the embedding amount of the male screw 87 in the screw holes 63a and 57a. It is possible to adjust the height position of the part. That is, the protruding member 85 forming the first seat portion 62 can adjust its tip position in the second direction (Y direction), and the protruding member 86 forming the second seat portion 66 can adjust its tip position. The position is adjustable in a third direction (Z direction).

By making the tip position of the projecting member 85 adjustable in the second direction, it is possible to adjust the pressing force with which the first holding portion 52 presses the mirror 38 . That is, by adjusting the tip position of the projecting member 85, it is possible to adjust the pressing force of the first holding portion 52 to be always constant. As a result, the transfer function of the vibration system including the mirror 38 and the resonance frequency of the mirror 38 can be further stabilized.

Further, by adjusting the tip position of the projecting member 86 in the third direction, it is possible to adjust the distance between the projecting portion 76 facing the projecting member 86 and the side surface 384 of the mirror 38 . Therefore, there is an advantage that the distance between the side surface 384 of the mirror 38 and the protrusion 76 can be adjusted to a constant state. Further, when the projection 76 is in contact with the side surface 384 of the mirror 38 when the holding member 70 is attached to the housing 50, the projection 76 is prevented from contacting the mirror 38 by increasing the embedding amount of the projection member 86 in the screw hole 67a. Since it can be adjusted so that it does not hit the side surface 384, there is also the advantage that the influence of variations in processing of the holding member 70 can be eliminated.

Although FIG. 16 illustrates the case where the screw holes 63a and 67a are provided in the inclined surfaces 61 and 65 and the projecting members 85 and 86 are mounted in the screw holes 63a and 67a, the present invention is not limited to this. For example, a screw hole may be provided in a flat plate portion that constitutes the pressing portion 73 and the first drop-out preventing portion 75, and the projection member described above may be mounted in the screw hole.

Other points in this embodiment are the same as those described in the first embodiment.

(Fourth embodiment)
Next, FIG. 17 is a cross-sectional view showing still another form of the holding portion 51. As shown in FIG. The holding portion 51 holds the mirror 38 in a state in which the first holding portion 52 is in contact with a plurality of locations on the front and back surfaces 381 and 382 of the mirror 38 and presses the mirror 38 . For example, the inclined surface 61 of the housing 50 is provided with two first seating portions 62 similar to those of the first embodiment. The first seats 62 provided at two positions contact the rear surface 382 of the mirror 38 respectively. The pressing portion 73 is formed with projections 74 , 74 at two positions facing the first seating portion 62 . The pressing portion 73 brings the two protrusions 74 , 74 into contact with the surface 381 of the mirror 38 and presses the mirror 38 toward the first seating portion 62 . In this manner, the first holding portion 52 holds the mirror 38 while pressing both the front and back surfaces thereof. In this manner, the mirror 38 can be held stably by the first holding portion 52 contacting the front and back surfaces 381 and 382 of the mirror 38 at a plurality of locations to hold the mirror 38 .

As described above, the configuration in which the first holding portion 52 contacts the front and back surfaces 381 and 382 of the mirror 38 at a plurality of locations and holds the mirror 38 in a state of being pressed can be achieved by holding both ends of the mirror 38 in the longitudinal direction (first direction). It may be provided at one end, or may be provided only at one end.

Other points in this embodiment are the same as those described in each of the first to third embodiments.

(Modification)
Although preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be applied.

For example, in the above embodiment, the case where the mirror 38 as the optical element 5 is a rectangular parallelepiped was exemplified. However, the optical element 5 to which the present invention can be applied is not necessarily limited to a rectangular parallelepiped. For example, the shape of the optical element 5 may be trapezoidal, or may be curved in an arcuate shape. Alternatively, only one of the front and back surfaces of the optical element 5 may be curved in an arcuate shape.

Moreover, in the above-described embodiment, the mirror 38 was exemplified as an example of the optical element 5 . However, the optical element 5 is not limited to the mirror 38, and may be an elongated lens or an elongated light receiving element.

Further, in the above-described embodiment, an example was explained in which the surface of the front and back surfaces positioned in the second direction (Y direction) of the optical element 5 is the optical functional surface. However, the optical functional surface of the optical element 5 is not limited to the front surface, and may be provided on the back surface, or may be provided on both the front and back surfaces. In the above embodiment, the optical function surface is a reflective surface, but the optical function surface is not necessarily limited to a reflective surface, and exhibits some optical action such as light gathering action, scattering action, or refraction action. Good if

Further, in the above embodiment, an example in which the second seating portion 66 is arranged in contact with one side surface 383 of the mirror 38 has been described. However, the second seat 66 may be arranged so as not to contact one side surface 383 of the mirror 38 . In this case, even if the mirror 38 were to vibrate, no friction would occur between the second seat 66 and the mirror 38, so that the transfer function of the vibration system including the mirror 38 and the resonance frequency of the mirror 38 would be much more stable. It has the advantage of being able to

Further, in the above-described embodiment, the pressing portion 73 is configured by an elastic body having a leaf spring structure, and a pressing force is applied to the mirror 38 as an example. However, the mode in which the pressing portion 73 applies the pressing force is not limited to the plate spring structure, and an elastic body structure such as a coil spring may be employed.

Further, in the above-described embodiment, the case where the optical device 33 having the characteristic configuration of the present invention is mounted on the optical writing device 30 has been exemplified. However, the invention is not limited to this, and the optical device having the characteristic configuration of the present invention can also be mounted in the image reading device 40 of the scanner section 3 . For example, image reader 40 includes mirrors 45, 46, and 47 as described above. Therefore, as the structure for holding the mirrors 45, 46, and 47, the structure of the holding portion 51 of the optical device 33 described above may be adopted.

REFERENCE SIGNS LIST 1 image processing device 5 optical element 30 optical writing device 33 optical device 38 mirror (optical element)
40 image reader 51 (51a, 51b) holding portion 52 first holding portion 53 second holding portion 54 third holding portion 62 first seating portion 64 steel ball 66 second seating portion 68 steel ball 73 pressing portion

Claims (18)

It has a predetermined length in a first direction, a predetermined thickness in a second direction orthogonal to the first direction, and a third direction orthogonal to the first direction and the second direction. an optical element having a predetermined width in the direction of and the predetermined length being longer than the predetermined thickness and the predetermined width;
a first holding part that contacts both front and back surfaces of the optical element positioned in the second direction at both ends of the optical element in the first direction and holds the optical element while pressing both the front and back surfaces; ,
Both ends of the optical element in the first direction are arranged so as to face two side surfaces of the optical element positioned in the third direction at an interval wider than the predetermined width, and the optical element is positioned in the third direction. a second holding portion that prevents movement in the direction of 3;
with
The optical device, wherein the optical element is held by the first holding portion and the second holding portion in a state in which no pressing force acts in the third direction. The first holding part is
a first seating portion bonded to one of the front and back surfaces of the optical element;
a pressing portion disposed at a position facing the first seating portion and bonded to the other surface of the front and back surfaces of the optical element to press the optical element toward the first seating portion;
2. The optical device of claim 1, comprising: the first seating portion is in point contact with one of the front and back surfaces of the optical element;
3. The optical device according to claim 2, wherein the pressing portion is in point contact with the other surface of the front and back surfaces of the optical element. The first seating portion is composed of a steel ball,
4. The optical device according to claim 2, wherein the pressing portion is formed of an elastic body, and presses the optical element toward the first seating portion by elastic force of the elastic body. 5. The optical device according to claim 2, wherein the first seating portion is arranged at a plurality of locations in the third direction. 6. The optical device according to claim 1, wherein the second holding portions are arranged so as to face each other at a position near the center of the side surface in the second direction. 7. The optical device according to claim 1, wherein the first holding portion and the second holding portion are provided at the same position in the first direction of the optical element. 8. The optical device according to claim 1, wherein the optical element has a thickness in the second direction smaller than a width in the third direction. 9. The optical device according to any one of claims 1 to 8, wherein the second holding section has a pair of protrusions that are capable of making point contact with each of the two side surfaces of the optical element. . 10. The optical device according to claim 9, wherein the tip position of at least one of the pair of projections is adjustable in the third direction. The second holding part is
a second seat bonded to one of the two side surfaces of the optical element;
a drop-off prevention portion arranged at a position spaced apart from the other of the two side surfaces of the optical element by a predetermined distance;
11. The optical device according to any one of claims 1 to 10, comprising: 12. The optical device according to claim 11, wherein the second seating portion has higher rigidity than the drop-off prevention portion and is arranged at a lower position than the drop-off prevention portion. The optical element is arranged so as to face two end faces positioned in the first direction at an interval wider than the length of the optical element in the first direction, and prevents the optical element from moving in the first direction. a third holding part to
13. The optical device according to any one of claims 1 to 12, further comprising: 14. The optical device according to any one of claims 1 to 13, wherein the optical element has a rectangular parallelepiped shape. 15. The optical device according to any one of claims 1 to 14, wherein at least one of the front and back surfaces of the optical element is an optically functional surface. 15. The optical device according to claim 14, wherein the optical functional surface of the optical element is a reflecting surface. a light source;
a polarizer that deflects and scans the light from the light source;
17. The optical device according to any one of claims 1 to 16, arranged in the traveling direction of the light deflected and scanned by the polarizer;
with
An optical writing device, wherein an image is written by light projected from the optical device. An optical device according to any one of claims 1 to 16,
An image processing device that reads an image or writes an image with light projected from the optical device.

Images