JP6115242B2 - Scanning optical device - Google Patents

Description

  The present invention relates to a scanning optical device configured to scan a scanning target by emitting a plurality of light beams.

  In general, a scanning optical device includes a light source that emits a light beam for scanning a scanning target, a deflector such as a polygon mirror that deflects the light beam emitted from the light source in the main scanning direction, a reflecting mirror that reflects the light beam, and an optical path. It is comprised with the lens etc. which are arrange | positioned. For example, Patent Document 1 discloses a scanning optical device including four light sources and one deflector in a frame. Patent Document 2 discloses a laser printer in which one scanning optical device is provided for each of four photosensitive drums to be scanned, and each scanning optical device has one in a frame. It has one light source and one deflector.

JP 2012-252126 A JP 2008-39905 A

  By the way, the scanning optical device including four light sources and one deflector in the frame needs to secure a space for turning back the optical path in the frame in order to adjust the optical path length of each light beam. It was increasing in size. Further, since all the light sources and optical elements are provided in the same frame, there is a problem that all the light sources and optical elements are affected by dimensional changes due to thermal expansion of the frame.

  On the other hand, a scanning optical device having one light source and one deflector in the frame can suppress an increase in the size of the frame, but when used in a laser printer or the like, the photosensitive drum of the scanning optical device is used. Since it was necessary to adjust the position with respect to each, it takes time to assemble. In addition, for example, when used in a laser printer having four photosensitive drums, four scanning optical devices are required, which increases the size of the laser printer and increases the number of components as a whole. It was.

  The present invention has been made in view of the above background, and an object of the present invention is to provide a scanning optical device capable of reducing the number of parts while suppressing the influence of dimensional changes of the frame.

In order to achieve the above-described object, the scanning optical apparatus of the present invention includes a first scanning unit, a second scanning unit, and a fixing member.
The first scanning unit includes a first light source for emitting a light beam for scanning a scanning target, a first deflector for deflecting the light beam from the first light source, and a first light source on the optical path. A first optical element disposed between the first deflector and the first deflector or between the first deflector and the scanning target, and a first light source, a first deflector, and a first optical element. And a first frame.
The second scanning unit includes a second light source for emitting a light beam for scanning the scanning target, a second deflector for deflecting the light beam from the second light source, and a second light source on the optical path. A second optical element disposed between the first deflector and the second deflector or between the second deflector and the object to be scanned, a second light source, a second deflector, and a second optical element. And a second frame.
The fixing member is a common member that fixes the first optical element to the first frame and fixes the second optical element to the second frame.

  According to such a configuration, the number of parts of the scanning optical device can be reduced as compared with a configuration in which each scanning unit is provided with a member for fixing the optical element to the frame. The first light source, the first deflector, and the first optical element are accommodated in the first frame, and the second light source, the second deflector, and the second optical element are accommodated in the second frame. Therefore, the influence of the dimensional change of the other frame on the light source, deflector, and optical element in one frame can be suppressed.

  The scanning optical device described above includes a first cover that covers the first light source, the first deflector, and the first optical element housed in the first frame, and the second cover housed in the second frame. A second cover that covers the light source, the second deflector, and the second optical element, and at least one of the first cover and the second cover holds the fixing member. it can.

  According to this, since it is not necessary to provide a separate component for pressing the fixing member, the number of components of the scanning optical device can be reduced.

  In the scanning optical device described above, the first cover and the second cover may be formed integrally.

  According to this, the number of parts of the scanning optical device can be reduced as compared with the configuration in which the first cover and the second cover are provided separately.

  In the above-described scanning optical device, the first optical element and the second optical element can be configured to be mirrors for reflecting the light beam.

  According to this, compared with the case where the first optical element and the second optical element are lenses through which a light beam passes, the first optical element (first scanning unit) and the second optical element (first optical element) 2 scanning units) can be arranged close to each other, so that the fixing member and the scanning optical device can be reduced in size.

  In the scanning optical device described above, the first frame has a first fixing surface to which the first deflector is fixed, and the second frame has a second fixing to which the second deflector is fixed. And the first optical element and the second optical element have the same incident angles of incident light beams, and are incident on the first optical element in the sub-scanning direction orthogonal to the main scanning direction. The distance from the first fixed surface to the first fixed surface and the distance from the incident point on the second optical element to the second fixed surface may be the same.

  According to this, since it is possible to use the same component as the first optical element and the second optical element, it is possible to reduce the cost of the scanning optical device.

  In the scanning optical device described above, the first optical element and the second optical element are arranged so that the distance from the third fixed surface to which the first scanning unit and the second scanning unit are fixed is the same. It can be set as the structure currently made.

  According to this, the first optical element side portion and the second optical element side portion of the fixing member can be formed symmetrically. Therefore, when the fixing member is attached, the direction and position of the fixing member Therefore, it is easy to assemble the scanning optical device.

  In the scanning optical device described above, the fixing member may be configured such that the first optical element side portion and the second optical element side portion are formed symmetrically.

  According to this, when attaching the fixing member, there is no need to worry about the direction and position of the fixing member, so that the assembly of the scanning optical device is facilitated.

  In the above-described scanning optical device, the first scanning unit and the second scanning unit are disposed close to each other, and at least one of the first frame and the second frame does not have a wall between the other. It can be configured.

  According to this, the frame can be reduced in size because the wall is not provided, and the first scanning unit and the second scanning unit are arranged close to each other, so that the scanning optical device can be reduced in size. Can do.

  In the above-described scanning optical device, the first frame and the second frame may have a coupling structure that can be fitted to each other for coupling one to the other.

  According to this, since the first scanning unit and the second scanning unit can be easily connected, the assembly of the scanning optical device is facilitated.

  In the above-described scanning optical device, the first scanning unit and the second scanning unit may have the same configuration.

  According to this, since the scanning unit (parts constituting the scanning unit) can be made common, the cost of the scanning optical device can be reduced.

  According to the present invention, it is possible to reduce the number of parts while suppressing the influence of the dimensional change of the frame.

1 is a diagram illustrating a schematic configuration of an image forming apparatus in which a scanning optical device according to an embodiment is used. It is a disassembled perspective view of a scanning optical apparatus. It is a perspective view which shows a 1st scanning unit, a 2nd scanning unit, and a fixed spring. It is a top view of the 1st scanning unit and the 2nd scanning unit. It is sectional drawing of a scanning optical apparatus. It is an expanded sectional view near a fixed spring. They are a perspective view (a) of a fixed spring and an enlarged perspective view (b) in the vicinity of one end of a mirror to which the fixed spring is attached. They are the side view (a) of the fixed spring attached to the flame | frame, and the expanded sectional view (b) near a fixing part. It is a perspective view which shows the structure of the flame | frame which concerns on a modification, and is the figure before connection (a) and the figure after connection (b). It is a perspective view which shows the structure of the flame | frame which concerns on another modification.

  Next, an embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In the following, the schematic configuration of the image forming apparatus using the scanning optical device 5 according to the present embodiment will be described first, and then the detailed configuration of the scanning optical device 5 will be described. In the following description, the direction will be described with reference to the user who uses the image forming apparatus. Specifically, the right side of FIG. 1 that is the front side when viewed from the user is “front”, the left side of FIG. 1 that is the back side when viewed from the user is “rear”, and the front side of FIG. "The back side of the paper is" right ". Further, the vertical direction in FIG.

<Schematic configuration of image forming apparatus>
As shown in FIG. 1, a laser printer 1 as an example of an image forming apparatus includes a paper feed unit 3 that supplies a sheet S in an apparatus body 2 and an image forming unit that forms an image on the supplied sheet S. 4 is mainly provided. The image forming unit 4 mainly includes a scanning optical device 5, a process unit 6, a transfer unit 7, and a fixing device 8.

  The paper feed unit 3 is provided at a lower portion in the main body housing 2, and mainly includes a paper feed tray 31 that stores the paper S, a paper pressing plate 32, and a paper feed mechanism 33. The sheets S in the sheet feeding tray 31 are moved upward by the sheet pressing plate 32, separated one by one by the sheet feeding mechanism 33, and supplied to the image forming unit 4.

  The scanning optical device 5 is provided in the upper part in the main body housing 2. Although the detailed configuration will be described later, the scanning optical device 5 is configured to emit a plurality of light beams (refer to chain lines) for scanning the photosensitive drum 61 as an example of a scanning target.

  The process unit 6 is disposed between the paper feed tray 31 and the scanning optical device 5, and is provided with four photosensitive drums 61 arranged side by side in the front-rear direction and one corresponding to each photosensitive drum 61. The charger 62 and the developing device 63 are mainly provided. Each developing device 63 includes a developing roller 64 that carries toner, a toner containing portion 67 that contains toner, and the like.

  The transfer unit 7 is provided between the paper feed tray 31 and the process unit 6, and includes a driving roller 71, a driven roller 72, and an endless conveyance belt 73 stretched between the driving roller 71 and the driven roller 72. Four transfer rollers 74 are mainly provided. The outer surface of the conveyance belt 73 is in contact with the photosensitive drum 61, and a transfer roller 74 is disposed inside the conveyance belt 73 so as to sandwich the conveyance belt 73 with the photosensitive drum 61.

  The fixing device 8 is provided behind the process unit 6 and the transfer unit 7, and mainly includes a heating roller 81 and a pressure roller 82 that is disposed to face the heating roller 81 and presses the heating roller 81.

  In the image forming unit 4, the surface of the photosensitive drum 61 is uniformly charged by the charger 62, and then exposed by a light beam emitted from the scanning optical device 5 based on the image data, thereby the photosensitive drum. An electrostatic latent image is formed on 61. Then, the toner carried on the developing roller 64 is supplied to the photosensitive drum 61, whereby the electrostatic latent image is visualized and a toner image is formed on the photosensitive drum 61. Thereafter, the sheet S supplied from the sheet feeding unit 3 passes between the photosensitive drum 61 and the conveyance belt 73, whereby the toner image on the photosensitive drum 61 is transferred onto the sheet S. The sheet S on which the toner image has been transferred passes between the heating roller 81 and the pressure roller 82 to thermally fix the toner image, and is discharged onto the discharge tray 22 by the transport roller 23 and the discharge roller 24.

<Detailed Configuration of Scanning Optical Device>
As shown in FIG. 2, the scanning optical device 5 includes a first scanning unit 5F, a second scanning unit 5R, a cover 5C, a seal member 5S, and two fixed springs 10 as an example of a fixed member. Is fixed to a metal support sheet metal 25 provided in the main body housing 2 of the laser printer 1 by screws (not shown) or the like (see also FIG. 1).

  The first scanning unit 5F and the second scanning unit 5R are arranged close to each other in the front-rear direction with the first scanning unit 5F as the front side and the second scanning unit 5R as the rear side. As shown in FIG. 3, each of the first scanning unit 5F and the second scanning unit 5R includes a frame 50, two light source devices 51, one polygon mirror 52, two scanning lenses 53, and a plurality of them. The mirrors 54 to 56 are mainly configured.

  In the present embodiment, the first scanning unit 5F and the second scanning unit 5R have the same configuration. Specifically, in the first scanning unit 5F and the second scanning unit 5R, the same components are used as the frame 50, the light source device 51, the polygon mirror 52, the scanning lens 53, and the mirrors 54 to 56, respectively. It is configured.

  In the following description, the main scanning direction is the scanning direction of the light beam on the photosensitive drum 61 and is the same as the longitudinal direction of the scanning lens 53 and the mirrors 54 to 56. The sub-scanning direction is a direction orthogonal to both the main scanning direction and the optical axis direction of the light beam. For example, in the frame 50, it is a direction corresponding to the vertical direction.

  Further, in the present specification and drawings, the photosensitive drum 61 is given the symbols A, B, C, D from the front side in the order in which it is arranged. Further, when the frame 50 and the polygon mirror 52 of the first scanning unit 5F are specified, the symbol F is given, and when the frame 50 and the polygon mirror 52 of the second scanning unit 5R are specified. , R symbol is attached. Furthermore, when specifying parts other than those described above, the symbols A, B, C, and D are assigned to the photosensitive drums 61A, 61B, 61C, and 61D, which are scanning targets, respectively.

  Therefore, in this embodiment, as shown in FIG. 4, the light source device 51B, the polygon mirror 52F, the mirror 54B, and the frame 50F of the first scanning unit 5F are “first light source” and “first deflector”. , “First optical element” and “first frame”, the light source device 51C, polygon mirror 52R, mirror 54C and frame 50R of the second scanning unit 5R are “second light source”, “first light source”, Corresponds to “second deflector”, “second optical element” and “second frame”.

  The light source device 51 is a device that emits a light beam for scanning the photosensitive drum 61, and mainly includes a semiconductor laser 511 that emits laser light and a coupling lens 512. The coupling lens 512 is a lens that converts the laser light from the semiconductor laser 511 into a light beam substantially parallel to the main scanning direction and forms an image on the mirror surface 521 of the polygon mirror 52 in the sub-scanning direction.

  The polygon mirror 52 is a member in which four mirror surfaces 521 are arranged at an equal distance from the rotation shaft 522. By rotating at a constant speed around the rotation shaft 522, the polygon mirror 52 reflects the light beam from the light source device 51 and is mainly reflected. Deflection in the scanning direction. The polygon mirror 52 is disposed in the center of the frame 50 so as to face the light source device 51 in the left-right direction.

  The scanning lens 53 is a lens through which the light beam deflected by the polygon mirror 52 passes, and is arranged one by one before and after the polygon mirror 52. The scanning lens 53 has a function of forming a light beam on the surface of the photosensitive drum 61 in a dot shape and correcting the surface tilt of the mirror surface 521 of the polygon mirror 52. The scanning lens 53 has an fθ characteristic that scans the light beam deflected by the polygon mirror 52 at a constant angular speed on the surface of the photosensitive drum 61 at a constant speed.

  The mirrors 54 to 56 are members that reflect the light beam that has passed through the scanning lens 53, and are formed, for example, by vapor-depositing a material having high reflectance such as aluminum on the surface of a glass plate. These mirrors 54 to 56 are arranged in the front part or the rear part in the frame 50. More specifically, as shown in FIG. 5, the mirror 54 is disposed on the opposite side of the polygon mirror 52 with the scanning lens 53 interposed therebetween, and reflects the light beam that has passed through the scanning lens 53 toward the mirror 55. The mirror 55 is disposed below the mirror 54 and reflects the light beam reflected by the mirror 54 toward the mirror 56. Further, the mirror 56 is disposed to face the mirror 55, and reflects the light beam reflected by the mirror 55 toward the photosensitive drum 61.

  The frame 50 is a member that accommodates the light source device 51, the polygon mirror 52, the scanning lens 53, and the mirrors 54 to 56, and is formed in a substantially box shape having an upper opening. The bottom surface 57 of the frame 50 supports the polygon mirror 52, the scanning lens 53, and the mirrors 54 to 56, and a plurality of columnar support portions to which these are fixed (the support portion of the mirror 54 is denoted by reference numeral 58). Is formed integrally with the frame 50. The bottom wall of the frame 50 and the support metal plate 25 are each formed with four openings (reference numerals omitted) that are long in the left-right direction for allowing the light beam reflected by the mirror 56 to pass therethrough.

  In the present embodiment, the bottom surface 57 of the frame 50F corresponds to the “first fixed surface”, and the bottom surface 57 of the frame 50R corresponds to the “second fixed surface”. Further, the upper surface 25A of the support metal plate 25 corresponds to a “third fixed surface” on which the first scanning unit 5F and the second scanning unit 5R are fixed.

  As shown in FIG. 6, in the present embodiment, the mirror 54B of the first scanning unit 5F and the mirror 54C of the second scanning unit 5R are center lines L passing through the center of the scanning optical device 5 when viewed from the left-right direction. Are arranged symmetrically. More specifically, in the mirrors 54B and 54C, the incident angle θ1 of the light beam incident on the mirror 54B is the same as the incident angle θ2 of the light beam incident on the mirror 54C, and the mirror 54B in the sub-scanning direction (vertical direction). The distance D11 from the incident point to the bottom surface 57 of the frame 50F and the distance D21 from the incident point to the mirror 54C to the bottom surface 57 of the frame 50R are arranged to be the same. Further, the mirrors 54B and 54C are arranged such that the distance D12 from the upper surface 25A of the support metal plate 25 to the mirror 54B and the distance D22 from the upper surface 25A to the mirror 54C are the same. In FIG. 6, illustration of support parts other than the support part 58 is omitted.

  Returning to FIG. 5, the cover 5 </ b> C is a member that covers optical components such as the light source devices 51 </ b> B and 51 </ b> C, polygon mirrors 52 </ b> F and 52 </ b> R, and mirrors 54 </ b> B and 54 </ b> C housed in the frames 50 </ b> F and 50 </ b> R. Is formed. The cover 5C of this embodiment is housed in a portion (corresponding to a “first cover”) that covers the optical components housed in the frame 50F of the first scanning unit 5F, and in the frame 50R of the second scanning unit 5R. The portion covering the optical component (corresponding to the “second cover”) is integrally formed as one component. The cover 5C is attached so as to cover the frames 50F and 50R, and then fixed to the frames 50F and 50R by screws or the like (not shown), so that the lower surface of the upper wall comes into contact with the left and right fixing springs 10 and is fixed. The fixed spring 10 is pressed so that the spring 10 does not come off.

  The seal member 5S is formed in a substantially rectangular frame shape from an elastic material such as urethane foam or rubber, and is sandwiched between the frames 50F, 50R and the cover 5C between the frames 50F, 50R and the cover 5C. Is arranged in. By providing such a seal member 5S, rattling noise between the frames 50F, 50R and the cover 5C, such as when a motor that rotates the polygon mirrors 52F, 52R is driven, is suppressed, Intrusion of foreign matter such as dust can be suppressed.

  As shown in FIGS. 7A and 7B, the fixing spring 10 is a first scanning unit 5F that fixes the mirror 54B to the frame 50F and fixes the mirror 54C to the frame 50R. It is a fixing component that is used in common with the second scanning unit 5R, and is attached to each of both end portions in the longitudinal direction of the mirrors 54B and 54C (see also FIGS. 2 and 4). The fixing spring 10 is formed by bending a band-shaped metal plate, and a pressing portion 11 disposed so as to be spanned between the mirrors 54B and 54C in an attached state, and a pair of fixing portions extending in the vertical direction. 12 and a pair of connecting portions 13 that connect the pressing portion 11 and the fixing portion 12 while forming a substantially U shape that escapes from the mirrors 54B and 54C. Each fixing portion 12 is formed with an engagement hole 14 that can be engaged with an engagement protrusion 58 </ b> P formed on the side surface of the support portion 58.

  As shown in FIG. 8A, in this embodiment, the fixed spring 10 includes a fixed spring front portion 10F that is a portion on the mirror 54B side and a fixed spring rear portion that is a portion on the mirror 54C side when viewed from the left-right direction. 10R is formed symmetrically with respect to the center line L of the scanning optical device 5.

  As shown in FIGS. 8 (a) and 8 (b), the fixed spring 10 has a support portion corresponding to the engagement hole 14 of each fixed portion 12 in a state where the end portion of the pressing portion 11 is abutted against the mirrors 54B and 54C. By being engaged with the engagement protrusion 58P of 58, it is attached to the frames 50F and 50R via the support portion 58. When the fixing spring 10 is attached to the frames 50F and 50R, the lifting of the fixing spring 10 is suppressed by the engagement between the engagement hole 14 and the engagement protrusion 58P, and thereby the end of the pressing portion 11 restricts the mirrors 54B and 54C. As a result, the mirrors 54B and 54C are fixed to the frames 50F and 50R.

According to the present embodiment described above, the following operational effects can be obtained.
Since the scanning optical device 5 includes the common fixing spring 10 that fixes the mirror 54B to the frame 50F and the mirror 54C to the frame 50R, the scanning units 5F and 5R correspond to the mirrors 54B and 54C, respectively. The number of parts can be reduced as compared with a configuration in which parts for fixing to the frame 50 are provided.

  In addition, since the fixing spring 10 is pressed by the cover 5C so that the fixing spring 10 is not detached, it is not necessary to provide a separate component for pressing the fixing spring 10, so that the number of components can also be reduced. Furthermore, since the frames 50F and 50R are covered with the single cover 5C, the number of parts can be reduced as compared with the configuration in which one cover is provided for each of the frames 50F and 50R.

  The light source devices 51A and 51B, the polygon mirror 52F, the mirrors 54A and 54B, and the like are accommodated in the frame 50F, and the light source devices 51C and 51D, the polygon mirror 52R, the mirrors 54C and 54D, and the like are provided separately from the frame 50F. Therefore, the light source device 51, the polygon mirror 52, the mirror 54, and the like in one frame 50 can be prevented from being affected by dimensional changes due to thermal expansion of the other frame 50.

  In addition, since the members fixed by the common fixing spring 10 are the mirrors 54B and 54C that reflect the light beam, the components (mirrors 54B and 54C) can be attached to each other as compared with the case where the lens through which the light beam passes is fixed by the common fixing spring. It can be placed close to each other. As a result, the scanning units 5F and 5R can be arranged close to each other, so that the fixed spring 10 and the scanning optical device 5 itself can be reduced in size.

  Further, the mirrors 54B and 54C are arranged so that the incident angles θ1 and θ2 are the same, and the distances D11 and D21 from the incident point to the bottom surfaces 57 of the frames 50F and 50R are the same. 54B and 54C can be made the same part. Further, since the scanning units 5F and 5R have the same configuration, each component other than the mirrors 54B and 54C can be the same component, and the scanning units 5F and 5R themselves can be shared. By these, cost reduction can be achieved.

  Further, since the mirrors 54B and 54C are arranged so that the distances D12 and D22 from the upper surface 25A of the support metal plate 25 are the same, the fixed spring 10 can be formed symmetrically. And in this embodiment, the fixed spring 10 is actually formed symmetrically. This eliminates the need to worry about the orientation and position of the fixing spring 10 when it is attached, thus facilitating assembly.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. About a concrete structure, it can change suitably in the range which does not deviate from the meaning of this invention as follows.

  For example, as shown in FIGS. 9A and 9B, the frame 150F as the first frame and the frame 150R as the second frame can be fitted to each other to connect one to the other. It may be a structure having As an example, the connection structure 60 includes a connection protrusion 60A formed at the rear end of the bottom wall of the frame 150F, and a connection recess 60B formed at the front end of the bottom wall of the frame 150R and fitable with the connection protrusion 60A. It can be set as the structure which has. According to such a configuration, the frame 150F (first scanning unit) and the frame 150R (second scanning unit) can be easily connected, so that the scanning optical device can be easily assembled. As illustrated in FIG. 10, the frame 150 </ b> F and the frame 150 </ b> R having the connection structure 60 may be the same component (both are the frames 150).

  Incidentally, the scanning optical device 5 has two frames 50F and 50R (or 150F and 150R) which are the same components, so that it is compared with a configuration in which all four light source devices and other optical components are accommodated in one frame. Thus, each frame 50 can be reduced in size. Thereby, size reduction of the manufacturing line etc. of the flame | frame 50 is attained.

  In the embodiment, the frames 50F and 50R are configured to have walls in the front, rear, left, and right. However, the present invention is not limited to this, and the two frames (the first frame and the second frame) include at least The configuration may be such that one does not have a wall between the other. Specifically, for example, as shown in FIGS. 9A and 9B, the frame 150F may have a configuration without a rear wall, and the frame 150R may have a configuration without a front wall. 2 and 3, only the frame 50F may have a configuration without a rear wall, or only the frame 50R may have a configuration without a front wall. According to this, at least one of the frames can be reduced in size because the wall is not provided, and the first scanning unit and the second scanning unit are disposed close to each other, thereby reducing the size of the scanning optical device as a whole. can do.

  In the embodiment, the cover 5C is integrally formed with a portion (first cover) that covers the optical component housed in the frame 50F and a portion (second cover) that covers the optical component housed in the frame 50R. However, the present invention is not limited to this. For example, the scanning optical device has a configuration in which a first cover that covers an optical component accommodated in a first frame and a second cover that covers an optical component accommodated in a second frame are provided separately. May be. In the configuration in which the scanning optical device includes two covers, at least one of the first cover and the second cover may be configured to press the fixed spring by abutting the fixed spring. . Note that, according to the cover 5C in which the portion covering the optical component housed in the frame 50F and the portion covering the optical component housed in the frame 50R are integrally formed as in the above embodiment, the frame 50F, 50R The accommodated optical component can be covered without a gap.

  In the above embodiment, the cover 5C presses the fixed spring 10 by the lower surface of the upper wall thereof directly contacting the fixed spring 10, but the present invention is not limited to this. For example, the cover abuts against the fixed spring via an elastic member such as urethane foam or rubber in order to suppress rattling noise between the cover and the fixed spring when a motor that rotates the polygon mirror is driven. May be.

  In the above embodiment, the fixed spring 10 is formed symmetrically, but the present invention is not limited to this. For example, the fixed spring has a first optical element side portion and a second optical element side portion. It may be formed asymmetrically. Moreover, in the said embodiment, although the metal fixing spring 10 was illustrated as a fixing member, this invention is not limited to this, For example, resin-made components etc. may be sufficient.

  In the embodiment, the first optical element and the second optical element are the mirrors 54B and 54C that reflect the light beam. However, the present invention is not limited to this, and for example, the first optical element and the second optical element The optical element may be a lens through which a light beam passes. In other words, in the embodiment, the first optical element and the second optical element arranged between the polygon mirror 52 (deflector) and the photosensitive drum 61 (scanning target) on the optical path of the light beam. However, the present invention is not limited to this. For example, the first optical element and the second optical element are respectively disposed between the light source and the deflector on the optical path of the light beam. It may be an optical element. Moreover, the first optical element and the second optical element are not limited to the same type of optical element, and may be different types of optical elements. For example, one of the first optical element and the second optical element may be a mirror and the other may be a lens.

  In the above embodiment, the same components are used as the frame 50, the light source device 51, the polygon mirror 52, the mirror 54, etc., so that the first scanning unit 5F and the second scanning unit 5R have the same configuration. However, the present invention is not limited to this. That is, the first scanning unit and the second scanning unit may have different configurations.

  In the above-described embodiment, the polygon mirror 52 has four mirror surfaces 521. However, the present invention is not limited to this. For example, the number of mirror surfaces may be six. In the above embodiment, the polygon mirror 52 is exemplified as the deflector. However, the present invention is not limited to this, and may be, for example, a vibrating mirror that deflects light by swinging.

  In the above-described embodiment, an example in which the scanning optical device of the present invention is used in an image forming apparatus such as the laser printer 1 has been described. Also good.

DESCRIPTION OF SYMBOLS 5 Scan optical apparatus 5C Cover 5F 1st scanning unit 5R 2nd scanning unit 10 Fixed spring 10F Fixed spring front part 10R Fixed spring rear part 25 Support sheet metal 25A Upper surface 50F Frame 50R Frame 51B Light source apparatus 51C Light source apparatus 52F Polygon mirror 52R Polygon Mirror 54B Mirror 54C Mirror 57 Bottom 61 Photoconductor drum

Claims (10)

A first light source for emitting a light beam for scanning a scanning target; a first deflector for deflecting the light beam from the first light source; the first light source on the optical path; and the first light source. A first optical element disposed between the deflector or between the first deflector and a scanning target, and the first light source, the first deflector, and the first optical element are accommodated. A first scanning unit comprising: a first scanning unit comprising:
A second light source for emitting a light beam for scanning a scanning target; a second deflector for deflecting the light beam from the second light source; the second light source on the optical path; and the second light source. A second optical element disposed between the deflector or between the second deflector and a scanning target, and the second light source, the second deflector, and the second optical element are accommodated. A second scanning unit having a second frame,
And a common fixing member for fixing the first optical element to the first frame and fixing the second optical element to the second frame. Scanning optical device. A first cover covering the first light source, the first deflector and the first optical element housed in the first frame;
A second cover that covers the second light source, the second deflector, and the second optical element housed in the second frame,
The scanning optical apparatus according to claim 1, wherein at least one of the first cover and the second cover presses the fixing member.   The scanning optical apparatus according to claim 2, wherein the first cover and the second cover are integrally formed.   4. The scanning optical apparatus according to claim 1, wherein the first optical element and the second optical element are mirrors for reflecting a light beam. 5. The first frame has a first fixing surface to which the first deflector is fixed;
The second frame has a second fixing surface to which the second deflector is fixed;
The first optical element and the second optical element have the same incident angles of incident light beams, and are from the incident point to the first optical element in the sub-scanning direction orthogonal to the main scanning direction. The distance to the first fixed surface and the distance from the incident point to the second optical element to the second fixed surface are arranged to be the same as each other. The scanning optical device according to claim 4.   The first optical element and the second optical element are arranged so that a distance from a third fixed surface to which the first scanning unit and the second scanning unit are fixed is the same. 6. The scanning optical apparatus according to claim 5, wherein   The scanning according to any one of claims 1 to 6, wherein the fixing member has a first optical element side portion and a second optical element side portion formed symmetrically. Optical device. The first scanning unit and the second scanning unit are arranged close to each other,
8. The scanning optical apparatus according to claim 1, wherein at least one of the first frame and the second frame does not have a wall between the other. 9.   The said 1st frame and the said 2nd frame have a connection structure which can be mutually fitted for connecting one side with the other, The Claim 1 characterized by the above-mentioned. Scanning optical device.   The scanning optical apparatus according to claim 1, wherein the first scanning unit and the second scanning unit have the same configuration.

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