JP2016151705A - Scanning optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scanning optical device that suppresses a deviation of a light reception face due to deformation of a housing, and correctly detects a light beam.SOLUTION: A scanning optical device comprises: a side wall 51 that is provided in at least a part of an outer periphery of a housing 50; a light pass unit 511 that is formed in the side wall 51 so that a light beam passes through; a fixing unit 512 that fixes a light reception unit 482 to the side wall 51 so that the light beam passing through the light pass unit 511 is incident upon a light reception face 481; and a structure body 55 that connects to the side wall 51. The structure body 55 is provided on an opposite side having the fixing unit 512 and the side wall 51 separated, or between the fixing unit 512 and the light pass unit 511.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a scanning optical apparatus for irradiating an image carrier while scanning with laser light in an electrophotographic system.

  The electrophotographic image forming apparatus includes a scanning optical device that forms an electrostatic latent image on the surface of the photosensitive drum by irradiating a scanned light beam while rotating the charged photosensitive drum. The scanning optical device includes an SOS (Start of Scan) sensor that detects the scanning start position of the light beam, and detects the writing position of the electrostatic latent image on the photosensitive drum.

  In order to form a high-precision electrostatic latent image on the photosensitive drum with high accuracy, it is necessary to accurately detect the writing position. Therefore, it is preferable that the SOS sensor is securely fixed to the housing of the scanning optical device so that the positional accuracy with respect to the scanned light beam is high. As a method for improving the positional accuracy of an electronic component such as an SOS sensor and securely fixing a substrate on which the electronic component is mounted, for example, a method as shown in Patent Document 1 is adopted.

  The substrate fastening structure shown in Patent Document 1 is formed in a direction perpendicular to the first surface, and a reference portion having a reference groove formed in a direction perpendicular to the first surface formed inside the housing. And a substrate on which an electronic component is mounted is inserted so as to straddle the reference groove and the opposing groove. And it fixes and fixes by pressing the recessed part provided in the board | substrate with the fastening member inserted in the through-hole provided in the opposing part.

  By having the board fastening structure having such a configuration, it is possible to maintain high positional accuracy of the electronic component with respect to the housing and to fix the electronic component firmly.

JP 2012-185227 A

  However, although the board fastening structure described in Patent Document 1 has a high positional accuracy with respect to the casing of the electronic component, the position of the electronic component is displaced when the casing itself is deformed by an external force or the like, and erroneous detection is performed. May lead to

  In recent years, scanning optical devices have been developed in which a substrate on which an SOS sensor is mounted is attached to the outer surface of a housing for the purpose of downsizing and facilitating wiring with a light source driving substrate. The board fastening structure described in Patent Document 1 is difficult to cope with the positioning of the board attached to the outer surface of the housing.

  Accordingly, an object of the present invention is to provide a scanning optical device that suppresses a shift of a light receiving surface due to deformation of a housing and accurately detects a light beam.

  In order to achieve the above object, the present invention is a scanning optical device that scans a light beam that irradiates an irradiation target surface, a scanning optical system that scans the light beam, and a light receiving unit that receives the light beam on a light receiving surface The housing is formed on the side wall so that at least one light beam at the start of scanning or at the end of scanning passes through the side wall provided on at least a part of the outer periphery. A light passing portion; a fixing portion provided outside the side wall; wherein the light receiving portion is fixed so that a light beam passing through the light passing portion is incident on the light receiving surface; and a structure connected to the side wall. The structure is provided on the opposite side of the fixed part and the side wall or between the fixed part and the light passage part.

  According to this configuration, when an external force or thermal stress is applied to the side wall, the structure that connects to the side wall is provided between the light passage part and the fixed part or on the opposite side of the fixed part. Since the structure is provided in this way, even if the light passing part side which is easily deformed due to external force acting on the side wall is deformed, the deformation is deformed around the connection part between the side wall and the structure. The fixing part fixing the light receiving part is not easily affected by deformation. Thereby, even if the side wall is deformed, the positional deviation of the light receiving surface can be suppressed, so that the light beam can be received at a certain position. Thereby, it is possible to suppress variation in the accuracy of light beam reception.

  In the above configuration, the light passage portion may be an aperture hole formed so that a projection shape in the light beam passage direction is larger than a projection shape in the light beam passage direction of the light receiving surface of the light receiving portion. With this configuration, the light beam can enter the light receiving surface without being disturbed by the side wall. As a result, the light beam can be received with high accuracy.

  In the above configuration, a scanned light beam may be incident on the light receiving surface, and the structure may be provided so as to intersect a scanning plane of the light beam incident on the light receiving surface.

  In the above configuration, the structure may be formed so as not to cross an optical path of a light beam incident on the light receiving surface.

  The said structure WHEREIN: The said fixing | fixed part may fix the said light-receiving part so that the said light-receiving surface may shift | deviate outside the outer surface of the said side wall in the advancing direction of the said light beam. By fixing in this way, it is possible to suppress erroneous detection due to the light beam scanned by deforming the side wall being irradiated on the inner surface of the light passing portion and the reflected light being incident on the light receiving surface.

  In the above configuration, the structure may be a wall. The wall body may be provided to reinforce the side wall, or may be a wall body formed for the purpose of partitioning the inside of the housing or attaching components. The wall body may be a rib provided for reinforcement.

  The said structure WHEREIN: The said structure may be provided with the wall part which has a surface facing the said side wall, and the connection part which connects the said side wall and the said wall part.

  ADVANTAGE OF THE INVENTION According to this invention, the scanning optical apparatus which suppresses the shift | offset | difference of the light-receiving surface by deformation | transformation of a housing | casing and detects a light beam correctly can be provided.

1 is a diagram illustrating an example of an image forming apparatus including a scanning optical device according to the present invention. 1 is a schematic layout diagram of a scanning optical device according to the present invention. It is the perspective view seen from the lower surface of the housing | casing of the scanning optical apparatus concerning this invention. FIG. 4 is an enlarged perspective view of a portion to which an element of the housing shown in FIG. 3 is attached. It is an expanded sectional view of the attachment part of the light-receiving part of the scanning optical apparatus concerning this invention. It is a figure which shows the state which the side wall of the housing | casing of the scanning optical apparatus concerning this invention is deform | transforming with the force from the outside. It is a figure which shows the state which the side wall of the housing | casing of the scanning optical apparatus for comparison is deform | transforming with the force from the outside. It is an expanded sectional view of the attachment part of the light-receiving part of the other example of the scanning optical apparatus concerning this invention. It is an expanded sectional view of the attachment part of the light-receiving part of the further another example of the scanning optical apparatus concerning this invention. It is an expanded sectional view of the attachment part of the light-receiving part of the further another example of the scanning optical apparatus concerning this invention. It is a figure which shows the state which the side wall of the housing | casing of the scanning optical apparatus shown in FIG. 10 is deform | transforming with the force from the outside. It is an expanded sectional view of the attachment part of the further another example of the light-receiving part of the scanning optical apparatus concerning this invention.

  FIG. 1 is a diagram showing an example of an image forming apparatus provided with a scanning optical device according to the present invention. In the following description, there are cases where directions such as up / down / left / right or clockwise counterclockwise are described, but FIG. 1 is used as a reference unless otherwise specified.

  An image forming apparatus A shown in FIG. 1 is a tandem color digital copier, and includes an image reader unit 20 that reads an original image, a printer unit 10 that prints the read image on a transfer material such as a recording sheet, and a printer unit 10. On the other hand, a paper feeding unit 30 for supplying a transfer material (here, recording paper) and a scanning optical device 40 for forming an electrostatic latent image on the surface of the photosensitive drums 11Y, 11M, 11C, and 11K are provided. Yes. The image forming apparatus A includes a control unit Cont, and the printer unit 10, the image reader unit 20, the paper feeding unit 30, and the scanning optical device 40 are controlled by the control unit Cont.

  The image reader unit 20 reads a document placed on a document glass plate (not shown) by moving a scanner, and has a known configuration. The image reader unit 20 separates the original image into three colors of red (R), green (G), and blue (B), converts them into electrical signals using an image sensor such as a CCD (not shown),・ G / B image data is acquired. The image data for each color (R, G, B) acquired by the image reader unit 20 is subjected to various processes by the control unit Cont, and then yellow (Y), magenta (M), cyan (C), black ( K) is converted into image data of each reproduction color and stored in a recording unit (memory) provided in the control unit Cont. The image data of each reproduction color stored in the memory in the control unit Cont is subjected to positional deviation correction, and then read out for each scanning line to become a drive signal. This drive signal is a signal for driving the scanning optical device 40.

  The printer unit 10 forms an image on a recording medium such as a recording sheet by an electrophotographic method. The printer unit 10 includes photosensitive drums 11Y, 11M, 11C, and 11K corresponding to reproduction colors of yellow (Y), magenta (M), cyan (C), and black (K). The drum 11 ”).

  Around each of the photosensitive drums 11Y, 11M, 11C, and 11K, a charger 111, a developing device 112, a transfer roller 113, and a cleaning unit 114 are provided. In FIG. 1, for convenience, only the charger 111, the developing device 112, the transfer roller 113, and the cleaning unit 114 around the photosensitive drum 11Y are denoted by reference numerals, but the same applies to the periphery of each photosensitive drum. A configuration is provided.

  The charger 111 uniformly charges the surface of the photosensitive drum 11. Examples of the charger 111 include a non-contact type such as a corotron type and a scotron type, and a contact type using a contact type charging roller or charging brush, but are not limited thereto.

  The photosensitive drum 11 is an insulator in a dark place (dark place), and has a property that when irradiated with light (when exposed), the irradiated portion becomes a conductor. The photosensitive drum 11 utilizes this property, and an electrostatic latent image is formed by irradiating the surface of the rotating photosensitive drum 11 with a light beam scanned by the scanning optical device 40.

  The developing device 112 supplies toner having a charge to the photosensitive drum 11 on which the electrostatic latent image is formed, thereby adsorbing the toner to the surface of the photosensitive drum 11 to form a toner image. Examples of a method for forming a toner image include a method in which toner having a reverse charge is adsorbed on a portion where the charge is not lost by exposure, and a method in which the toner is pushed into the portion where the charge is lost.

  The transfer roller 113 is a roller for transferring a toner image formed on the surface of the photosensitive drum 11 to a transfer target (here, an intermediate transfer belt 14 described later). The transfer roller 113 is disposed on the opposite side of the photosensitive drum 11 with the transfer target interposed therebetween, and sucks toner from the photosensitive drum 11 by applying a charge (transfer bias) opposite to that of the toner. As a result, the toner image formed on the photosensitive drum 11 is transferred to the transfer target.

  The cleaning unit 114 eliminates the charge on the surface of the photosensitive drum 11 (discharges electricity), and further removes the toner remaining on the photosensitive drum 11. The neutralization can be performed by using a neutralization lamp that is performed by irradiating the photosensitive drum 11 with light, but is not limited thereto. Examples of a method for removing the toner remaining on the photosensitive drum 11 include, but are not limited to, a method of adsorbing with a charging brush and a method of scraping with a blade formed of rubber or the like.

  The printer unit 10 includes toner hoppers 12Y, 12M, 12C, and 12K and toner bottles 13Y, 13M, 13C, and 13K for supplying toner to the photosensitive drums 11Y, 11M, 11C, and 11K.

  The toner hoppers 12Y, 12M, 12C, and 12K temporarily store yellow (Y), magenta (M), cyan (C), and black (K) toners. When the amount of toner (toner density) in the developing device 112 that develops each of the photosensitive drums 11Y, 11M, 11C, and 11K becomes low, the toner is supplied to the corresponding developing device 112 via a cylindrical joint (not shown). .

  The toner bottles 13Y, 13M, 13C, and 13K are disposed above the toner hoppers 12Y, 12M, 12C, and 12K. The toner bottles 13Y, 13M, 13C, and 13K contain yellow (Y), magenta (M), cyan (C), and black (K), and the toner remaining in the toner hoppers 12Y, 12M, 12C, and 12K. When the amount decreases, toner is supplied. By replacing the toner bottles 13Y, 13M, 13C, and 13K, new toner can be supplied. Examples of the toner bottles 13Y, 13M, 13C, and 13K include those in which a spiral protrusion is formed on the inner peripheral surface of a cylindrical bottle. By rotating the toner bottles 13Y, 13M, 13C, and 13K, the toner in the toner bottles 13Y, 13M, 13C, and 13K falls from the discharge port and flows into the toner hoppers 12Y, 12M, 12C, and 12K.

  In the printing unit 10, toner images of yellow (Y), magenta (M), cyan (C), and black (K) formed on the photosensitive drums 11Y, 11M, 11C, and 11K are superimposed and transferred (primary After the transfer, the image is transferred (secondary transfer) to a recording paper as a transfer material, and further fixed, whereby a color image is printed. The print unit 10 includes an intermediate transfer belt 14, a secondary transfer roller 15, a fixing unit 16, and a cleaning blade 17 in order to enable such a procedure.

  The intermediate transfer belt 14 is an endless belt, and is stretched between the driving roller 141, the driven roller 142, and the tension roller 143. As shown in FIG. 1, the tension roller 143 is disposed at a position higher than the driving roller 141 and the driven roller 142. The tension roller 143 is configured to be biased upward by an unillustrated biasing member (for example, a spring), and the tension roller 143 is biased upward, whereby tension is applied to the intermediate transfer belt 14. Is given. Note that the tension roller 143 may be omitted in a configuration in which at least one of the driving roller 141 or the driven roller 142 can be urged away.

  Below the intermediate transfer belt 14, photosensitive drums 11Y, 11M, 11C, and 11K are arranged at predetermined intervals in order from the left. The photoconductive drums 11Y, 11M, 11C, and 11K are arranged so that the rotation axis thereof is orthogonal to the moving direction of the intermediate transfer belt 14. Further, a transfer roller 113 is disposed so as to sandwich the intermediate transfer belt 14 with each of the photosensitive drums 11Y, 11M, 11C, and 11K.

  The intermediate transfer belt 14 is rotated counterclockwise by the driving roller 141. The toner images from the photoconductive drums 11Y, 11M, 11C, and 11K are transferred in synchronization with the intermediate transfer belt 14 to transfer yellow (Y), magenta (M), and cyan (C) to the intermediate transfer belt 14. The black (K) toner image is accurately superimposed and transferred (primary transfer). As a result, a color toner image (referred to as a primary transfer image) is formed on the surface of the intermediate transfer belt 14.

  The secondary transfer roller 15 is in pressure contact with the drive roller 141 with the intermediate transfer belt 14 interposed therebetween. A secondary transfer bias is applied to the secondary transfer roller 15 to attract toner from the primary transfer image of the intermediate transfer belt 14. The fixing unit 16 fixes the toner image on the recording paper by heating and pressurizing the recording paper on which the toner image is transferred.

  The cleaning blade 17 is a plate-like member such as rubber, and is pressed toward the driven roller 142 with the intermediate transfer belt 14 interposed therebetween. The cleaning blade 17 scrapes off the toner remaining on the intermediate transfer belt 14.

  Next, the paper feeding unit 30 that supplies recording paper to the printer unit 10 will be described. The paper feed unit 30 includes a paper feed cassette 31, a paper feed roller 32, and a registration roller 33. The paper feed cassette 31 is a storage unit for storing recording paper. The paper feed cassette 31 is detachable and can be replenished with recording paper. In the image forming apparatus A, one sheet feeding cassette 31 is shown, but the present invention is not limited to this, and a plurality of sheet feeding cassettes may be provided. When a plurality of paper feeding cassettes are provided, for example, recording papers having different sizes and colors may be stored for each paper feeding cassette, or the arrangement directions of the recording papers may be different.

  The paper feed roller 32 pulls out the recording paper disposed at the top of the paper feed cassette 31 to the transport path (indicated by a broken line) and transports it to the registration roller 33. In the case where a plurality of paper feed cassettes 31 are provided, a paper feed roller 32 may be provided for each paper feed cassette 31.

  The registration roller 33 operates in synchronization with the rotation of the intermediate transfer roller 12, and the recording paper is transferred to the drive roller 141 and the secondary transfer so that the primary transfer image is transferred to a predetermined position on the recording paper. It is sent to the nip portion with the roller 15.

  When the recording paper passes through the nip portion between the driving roller 141 and the secondary transfer roller 15, the recording paper comes into contact with the intermediate transfer belt 14. At this time, by applying a secondary transfer bias to the secondary transfer roller 15, the toner image on the intermediate transfer belt 14 is transferred (secondary transfer) to the recording paper. The recording paper to which the toner image has been transferred is then conveyed to the fixing unit 16. In the fixing unit 16, the toner image is fixed to the transfer material by heating and pressing. Then, the transfer material on which the toner image is fixed is discharged to the outside of the apparatus. On the other hand, the residual toner remaining on the intermediate transfer belt 14 without being transferred is collected by the cleaning blade 17 and stored in a waste toner box.

  In the image forming apparatus A, the toner images of the respective photosensitive drums 11Y, 11M, 11C, and 11K are transferred onto the intermediate transfer belt 14 so as to obtain a color primary transfer image. In order to accurately superimpose the primary transfer images, as described above, the intermediate transfer belt 14 and the photosensitive drums 11Y, 11M, 11C, and 11K are accurately synchronized, and the photosensitive drums 11Y, 11M, The toner images formed on 11C and 11K, that is, electrostatic latent images, must be accurately and reliably synchronized. In the image forming apparatus A of the present invention, an electrostatic latent image is created on each of the photosensitive drums 11Y, 11M, 11C, and 11K using the scanning optical device 40.

  Next, the configuration of the scanning optical apparatus A will be described with reference to the drawings. FIG. 2 is a schematic layout diagram of the scanning optical apparatus according to the present invention.

  As shown in FIG. 2, the scanning optical device 40 includes light sources 41Y, 41M, 41C, and 41K, a collimator lens 42, reflecting members (mirrors) 43Y, 43M, 43C, and 43K, an adjustment mirror 43R, and a deflector 44. And an optical element 45, scanning reflection portions 46Y, 46M, 46C, and 46K, a detection mirror group 47, and a light receiving portion 48. In the scanning optical device 40, these members are attached to a housing 50 which is an integrally molded body of resin.

  The light sources 41Y, 41M, 41C, and 41K are light sources that emit light beams for exposing each of the photosensitive drums 11Y, 11M, 11C, and 11K. Here, the light sources 41Y, 41M, 41C, and 41K are laser diodes that emit laser light as light beams. . The light sources 41Y, 41M, 41C, and 41K are fixed to the side wall 51 of the housing 50 while being mounted on the substrate Bd. A passage hole through which the light beam passes is formed in the side wall 51 of the housing 50. The light source 41Y, 41M, 41C, 41K receives a drive signal for each scanning line from the control unit Cont, and emits a pulsed light beam based on this drive signal.

  The collimator lens 42 is disposed on the light exit surface side of each of the light sources 41Y, 41M, 41C, and 41K, and optical that converts the light beams emitted from the light sources 41Y, 41M, 41C, and 41K from diffused light to parallel light. It is an element.

  The light beams emitted from the light sources 41Y, 41M, 41C, and 41K are reflected by the reflecting members 43Y, 43M, 43C, and 43K, and are applied to the adjustment mirror. As shown in FIG. 2, the optical paths of the light beams emitted from the light sources 41Y, 41M, 41C, and 41K overlap each other, but the light sources 41Y, 41M, 41C, and 41K in the thickness direction in FIG. Since the installation heights are different, they actually have different optical paths (see FIG. 1). The adjustment mirror 43R reflects the light beams reflected by the reflecting members 43Y, 43M, 43C, and 43K toward the deflector 44.

  The deflector 44 includes a polygon mirror 441 having a plurality of reflecting surfaces arranged side by side in the circumferential direction, and a deflection motor 442 (see FIG. 1) that rotates the polygon mirror 441. As shown in FIG. 2, the polygon mirror 441 employs a regular pentagonal prism shape having five reflecting surfaces on the outer peripheral surface, but is not limited thereto. The light beam reflected by the adjustment mirror 43R is incident at a constant angle with respect to the central axis of the polygon mirror 441. By rotating the polygon mirror 441, the incident angle and reflection angle of the light beam incident on the reflecting surface of the polygon mirror 441 change. That is, the reflected light beam is scanned by irradiating the rotating polygon mirror 441 with the light beam from the side surface.

  By synchronizing the rotation of the polygon mirror 441 of the deflector 44 with the pulsed light beams emitted from the light sources 41Y, 41M, 41C, and 41K, exposure of the photosensitive drums 11Y, 11M, 11C, and 11K of the light beams is performed. It is done with high accuracy. These synchronizations are performed by a drive signal from the control unit Cont.

  The optical element 45 is disposed in the housing 50 so that the light beam scanned by the polygon mirror 441 is transmitted. Then, the light beam transmitted through the optical element 45 is incident on the scanning reflectors 46Y, 46M, 46C, and 46K that reflect the light beam toward the photosensitive drums 11Y, 11M, 11C, and 11K, respectively. The light beam is incident on the scanning reflection portions 46Y, 46M, 46C, and 46K at points (spots), and the spot moves in the longitudinal direction of the scanning reflection portions 46Y, 46M, 46C, and 46K by scanning the light beam.

  The optical element 45 includes an optical element such as an fθ lens, and transmits light so that the moving speed of the spot of the light beam on the scanning reflectors 46Y, 46M, 46C, and 46K is constant in the linear direction. Adjust the beam.

  The light beams incident on the scanning reflection units 46Y, 46M, 46C, and 46K are further reflected by the reflecting member 46a (see FIG. 1) as necessary, and enter the photosensitive drums 11Y, 11M, 11C, and 11K. The scanning optical device 40 has a structure in which the light beam is reflected by a plurality of reflecting members, whereby the distance of the optical path from the light sources 41Y, 41M, 41C, and 41K to the surfaces of the photosensitive drums 11Y, 11M, 11C, and 11K. Are adjusted to be equal or approximately equal.

  The scanning optical device 40 is arranged so that the scanning direction (main scanning direction) of the light beam incident on the photosensitive drums 11Y, 11M, 11C, and 11K is parallel to the rotation axis of the photosensitive drums 11Y, 11M, 11C, and 11K. Has been. Then, the scanning optical device 40 irradiates the photosensitive drums 11Y, 11M, 11C, and 11K with the scanned light beam and exposes each scanning line to form an electrostatic latent image. In the case of such a configuration, it is necessary to accurately grasp the scanning start position of the light beam (the electrostatic latent image writing position). In the scanning optical device 40, the scanning start position is detected using the detection mirror group 47 and the light receiving unit 48.

  The detection mirror group 47 includes a first mirror 471 and a second mirror 472 disposed at the scanning start position. The light beam irradiated to the scanning start position is reflected by the first mirror 471 and enters the second mirror 472. The light beam reflected by the second mirror 472 is applied to the detection opening 511 provided on the side wall 51.

  The light receiving unit 48 includes a light receiving sensor 481 that converts the light beam into an electric signal when it receives the light beam, and a sensor substrate 482 on which the light receiving sensor 481 is mounted. And fixed to the side wall 51. The light receiving unit 48 is fixedly attached to the outer surface of the casing 51, and is attached so that the light beam transmitted through the detection opening 511 can be received by the light receiving sensor 481. The light receiving sensor 481 detects a light beam incident on the first mirror 471 disposed at the scanning start position, and plays a role of detecting the scanning start position. The light receiving unit 48 transmits a light reception signal to the control unit Cont. This light reception signal is a detection signal of the scanning start position, and the light reception sensor 481 is a so-called SOS (Start of Scan) sensor.

  In the scanning optical system device 40, a pulsed light beam corresponding to one scanning line of the image signal is emitted from the light sources 41Y, 41M, 41C, and 41K based on the drive signal from the control unit Cont. The polygon mirror 441 scans the light beam to form electrostatic latent images on the photosensitive drums 11Y, 11M, 11C, and 11K.

  The controller Cont adjusts the exposure start timing corresponding to one scan line of the image data of each reproduction color based on the information of the scan start position from the light receiving sensor 481. That is, it is used to synchronize the pulse of the light beam of the light sources 41Y, 41M, 41C, and 41K and the rotation of the polygon mirror 441. For this reason, the accuracy of the electrostatic latent images of each of the photosensitive drums 11Y, 11M, 11C, and 11K and the accuracy of synchronization of the electrostatic latent images are determined by the light reception signal from the light receiving unit 48 of the light receiving unit 48. The accuracy of the light reception signal is determined by the position of the light reception sensor 481.

  Therefore, in the scanning optical device according to the present invention, the housing 50 attached so that the position of the light receiving sensor 481 does not shift is used. Next, the housing of the scanning optical device, which is the main part of the present invention, will be described.

  FIG. 3 is a perspective view seen from the bottom surface of the housing of the scanning optical device according to the present invention, and FIG. 4 is an enlarged perspective view of a portion to which elements of the housing shown in FIG. 3 are attached. As shown in FIG. 3, the scanning optical device 40 includes a casing 50 formed by integral molding of resin. The housing 50 includes a side wall 51, a holding part 52, a reflection fixing part 53, a partition part 54, and a wall part 55.

  As shown in FIGS. 2 and 4, the housing 50 includes a first region 501 that is opened downward in which the collimator lens 42, the reflecting members 43 </ b> Y, 43 </ b> M, 43 </ b> C, and 43 </ b> K and the adjustment mirror 43 </ b> R are disposed, the deflector 44, The optical element 45, the scanning reflection portions 46Y, 46M, 46C, and 46K, and the second region 502 that is open upward are provided in which the detection mirror group 47 is disposed. As shown in FIG. 3, the casing 50 is formed so that the outer periphery is covered with the side wall 51, the first region 501 is formed so as to cover the upper side, and the second region 502 is formed so as to cover the lower side. Yes. By forming in this way, the first region 501 and the second region 502 are partitioned by the partition portion 54.

  As shown in FIG. 4, the holding portion 52 is a portion that covers the upper side of the first portion 501, and the reflection fixing portion 53 protrudes downward from the holding portion 52. The reflection members 43Y, 43M, 43C, 43K, and the adjustment mirror 43R are fixed to the reflection fixing portion 53 protruding from the holding portion 52 of the housing 50. The fixing of the reflecting members 43Y, 43M, 43C, 43K and the adjusting mirror 43R is performed by bringing one surface (reflecting surface) of the reflecting members 43Y, 43M, 43C, 43K and the adjusting mirror 43R into contact with one surface of the reflecting fixing portion 53, and curing with ultraviolet rays. It is fixed with resin. Note that one surface of the reflection fixing portion 53 serves to position the reflection surfaces of the reflection members 43Y, 43M, 43C, and 43K and the adjustment mirror 43R, so that the angle accuracy with respect to the light beam is increased. .

  As shown in FIGS. 2 and 3, the side wall 51 includes a detection opening 511 and a fixing portion 512. The detection opening 511 on the side wall is an opening through which the light beam reflected by the detection mirror group 47 passes, and the light beam that has passed through the opening enters the light receiving sensor 481 of the light receiving unit 48 fixed outside. The fixing portion 512 is provided to fix the sensor substrate 482 on which the light receiving sensor 481 is mounted. A wall portion 55 is provided inside the side wall 51.

  In the deflector 44, since the polygon mirror 441 is rotated by the deflection motor 442, heat is generated from the deflection motor 442. Further, an air flow is also generated by the rotation of the polygon mirror 441 and is heated by the heat of the deflection motor 442 to generate hot air. When such hot air is blown to the holding portion 52, the reflection fixing portion 53, which is an integrally molded resin body, is deformed or the adhesive is altered, and the reflecting members 43Y, 43M, and 43C. 43K and the optical accuracy of the adjustment mirror 43R may be reduced. The housing 50 includes a partition 54 that partitions the first region 501 and the second region 502, and the hot air from the deflector 44 blows on the reflecting members 43Y, 43M, 43C, 43K, and the adjustment mirror 43R. Suppressed.

  Note that the partition portion 54 is provided with a window portion 541 for transmitting the light beam reflected by the adjustment mirror 43R. The window 541 is preferably configured to transmit a light beam and block hot air.

  As shown in FIG. 4, the substrate Bd on which the light sources 41Y, 41M, 41C, and 41K are mounted and the sensor substrate 482 are attached to the outside of the housing 50 (the outer surface of the side wall 51). As described above, the substrate Bd and the sensor substrate 482 are attached to the outside, so that the substrates can be connected to each other by wiring. In addition, the wiring from the control unit Cont can be easily attached, the manufacturing is easy, and the maintainability can be improved.

  Next, details of the mounting portion of the sensor substrate, which is an essential part of the present invention, will be described with reference to the drawings.

(First embodiment)
FIG. 5 is an enlarged cross-sectional view of a mounting portion of the light receiving portion of the scanning optical apparatus according to the present invention. As described above, the scanning optical device 40 has a configuration in which the sensor substrate 482 mounted with the light receiving sensor 481 for detecting the scanning start position is fixed to the outside of the side wall 51.

  As shown in FIG. 5, the side wall 51 includes a detection opening 511 and a fixing portion 512. The fixing part 512 is a part for fixing the sensor substrate 482 of the light receiving part 48. The fixing portion 512 fixes the sensor substrate 482 with the screw Sc, but is not limited thereto. In addition to screwing, a method of firmly fixing the sensor substrate 482 to the side wall 51 (for example, adhesion, welding of the tip of the boss, etc.) may be employed.

  The fixing portion 512 includes a screw hole 513 in which a female screw is formed, and the sensor substrate 482 is fixed to the fixing portion 512 by screwing a screw Sc that passes through a through hole provided in the sensor substrate 482. Then, by fixing the sensor substrate 482 to the fixing portion 512 with the screw Sc, the light receiving sensor 481 is disposed at a position where the light beam from the detection opening 511 can be detected. That is, the screw Sc serves as a fixing tool for fixing the sensor substrate 482 and serves as a positioning member for positioning the sensor substrate 482.

  In FIG. 5, the light receiving sensor 481 is arranged inside the detection opening 511. That is, the projected shape of the detection aperture 511 in the traveling direction of the light beam has a shape and a size (projected area) in which the light receiving surface of the light receiving sensor 481 completely enters. By being formed in this manner, the light receiving sensor 481 is not easily hidden by the side wall 51, and the light beam reflected by the detection mirror group 47 of the light receiving sensor 481 can be reliably incident on the light receiving surface.

  In addition, the structure provided with the positioning member which positions the sensor board | substrate 482 in the fixing | fixed part 512 may be sufficient. As the positioning member, a positioning boss for positioning the sensor substrate 482 may be formed by standing from the side wall 51 and passing through a through hole provided in the sensor substrate 482. Alternatively, the positioning may be performed by pressing the side surface of the sensor substrate 482 with a rib standing from the side wall 51.

  A wall portion 55 that is connected to the side wall 51 and extends in a direction intersecting with the side wall 51 is formed in a portion between the detection opening 511 and the fixing portion 512 inside the side wall 51. The wall portion 55 is a wall body that protrudes in the same direction (downward) as the side wall 51 from the holding portion 52 that is the bottom surface of the first region 501. As shown in FIG. 5, the wall portion 55 is formed inside the housing 50. Accordingly, when the scanning optical device 40 is attached to the image forming apparatus A together with the casing 50, the wall portion 55 is not easily obstructed.

  Next, effects of the scanning optical device according to the present invention will be described with reference to the drawings. FIG. 6 is a diagram showing a state in which the side wall of the casing of the scanning optical device according to the present invention is deformed by an external force, and FIG. 7 shows the side wall of the casing of the scanning optical device to be compared from the outside. It is a figure which shows the state currently deform | transforming with force.

  When an external force is applied to the side wall 51, since the detection opening 511 is formed, the detection opening 511 side is more easily bent (deformed) by the external force than the wall portion 55 of the side wall 51. Since the wall portion 55 is provided in a direction intersecting the side wall 51, the side wall 51 is hardly deformed in the portion where the wall portion 55 is formed. That is, when an external force acts on the side wall 51 having a structure like the wall portion 55, the wall portion 55 is deformed with the fulcrum as a fulcrum.

  For example, in the case 50Q to be compared as shown in FIG. 7, the sensor substrate 482 is attached to the fixed portion 512q provided between the wall portion 55q provided to connect to the side wall 51q and the detection opening 511. It is fixed. When the force P1 from the outside acts on the side wall 51b of the housing 50Q having the structure, the wall portion 55q counters the force P1 in the housing 50Q. Therefore, the side wall 51q is deformed so as to rotate around the connection portion with the wall portion 55q. Since the sensor substrate 482 is fixed to the fixing portion 512q closer to the detection opening 511 than the wall portion 55q, the sensor substrate 482 is displaced along with the deformation of the side wall 51q, and the position of the light receiving sensor 481 (position relative to the detection mirror group 47). Changes. Thereby, the detection accuracy of the scanning start position by the light receiving sensor 481 is lowered.

  On the other hand, if the same force P1 as that for comparison is applied to the casing 50 of the scanning optical apparatus according to the present invention, the wall 50 counters the force P1 in the casing 50. Therefore, the side wall 51 is deformed so as to rotate around the connection portion with the wall portion 55 (see FIG. 6). Even when the side wall 51 rotates around the connection portion with the wall portion 55, the deformation of the side of the side wall 51 where the fixing portion 512 is formed is suppressed. Thereby, the movement of the sensor substrate 482 fixed to the fixing unit 512 is suppressed, and the change in the position of the light receiving sensor 481 (position with respect to the detection mirror group 47) is suppressed. Thereby, even when an external force is applied to the side wall 51 and the side wall 51 is deformed, a decrease in detection accuracy of the scanning start position by the light receiving sensor 481 can be suppressed. This makes it possible to accurately detect the scanning start position and form an electrostatic latent image with high accuracy.

  As described above, with the configuration of the present invention, even when the side wall 51 is deformed by an external force, the displacement of the sensor substrate 482, that is, the light receiving sensor 481 can be suppressed. Thus, the scanning optical device 40 can accurately detect the scanning start position even if the side wall 51 is deformed. In addition, since the side wall 51 is difficult to deform at a portion near the wall portion 55, the wall portion 55 is preferably provided at a portion near the fixing portion 512.

  The wall portion 55 has been described as a part of a partition wall for partitioning the first region 501, but is not limited to this. For example, it may be a rib provided to increase the strength, or may be a wall provided for other reasons. Note that the wall portion 55 preferably has the same or substantially the same height as the side wall 51. Moreover, although the case where an external force acts as a deformation | transformation of the side wall 51 is mentioned, it is not limited to this, For example, the deformation | transformation by a thermal stress, etc. are the same.

(Second Embodiment)
Another example of the scanning optical device according to the present invention will be described with reference to the drawings. FIG. 8 is an enlarged sectional view of a mounting portion of another example of the light receiving portion of the scanning optical device according to the present invention. As shown in FIG. 8, the casing 50B used in the scanning optical device 40 has the same configuration as the casing 50 of the first embodiment except that the position of the wall portion 55b is different. Therefore, substantially the same parts are denoted by the same reference numerals, and detailed description of the same parts is omitted.

  As shown in FIG. 8, in the housing 50B, the wall portion 55b is provided on the opposite side across the fixed portion 512 and the side wall 51b. That is, in the housing 50B, the position of the wall portion 55b and the fixed portion 512 in the direction along the side wall 51b from the detection opening 511 is the same position. Since the fixing portion 512 is formed in the portion reinforced by the wall portion 55b of the side wall 51b, the sensor substrate 482 can be fixed to the reinforced portion of the side wall 51b. Thereby, even if the side wall 51b is deformed by an external force, the sensor substrate 482, that is, the light receiving sensor 481 is not displaced or not substantially displaced, so that the scanning start position can be accurately detected. This makes it possible to accurately detect the scanning start position and form an electrostatic latent image with high accuracy.

(Third embodiment)
Another example of the scanning optical device according to the present invention will be described with reference to the drawings. FIG. 9 is an enlarged cross-sectional view of a mounting portion of a light receiving portion of still another example of the scanning optical device according to the present invention. As shown in FIG. 9, the casing 50C used in the scanning optical device 40 has the same configuration as the casing 50 of the first embodiment except that the angle of the wall portion 55c with respect to the side wall 51c is different. Therefore, substantially the same parts are denoted by the same reference numerals, and detailed description of the same parts is omitted.

  When the wall portion 55 is formed as a reinforcing member for the side wall 51, the wall portion 55 is preferably formed so as to be orthogonal to the side wall 51. However, there are cases where it is difficult to form the orthogonal wall portion 55 due to a problem with a member arranged in the housing or another device at the time of attachment. Therefore, as shown in FIG. 9, the housing 50 </ b> C includes a wall portion 55 c that is connected to the side wall 51 c at an angle other than a right angle.

  In the scanning optical device, the scanned light beam is incident on the light receiving sensor 481 depending on the size and angle of the detection mirror group 47 and the shape and size of the detection opening 511. The wall 55c has an angle with respect to the side wall 51c and a length from the side wall 51c so as not to block the scanned light beam so that the scanned light beam can be accurately incident on the light receiving sensor 481. Is adjusted. By adjusting the wall 55c, the light sensor 481 can reliably receive the scanned light beam. This makes it possible to accurately detect the scanning start position and form an electrostatic latent image with high accuracy.

(Fourth embodiment)
Another example of the scanning optical device according to the present invention will be described with reference to the drawings. FIG. 10 is an enlarged cross-sectional view of a mounting portion of a light receiving portion of still another example of the scanning optical apparatus according to the present invention. As shown in FIG. 10, the housing 50 </ b> D used in the scanning optical device 40 has the same configuration as that of the housing 50 of the first embodiment except that the fixing portion 514 is different.

  As shown in FIG. 10, the side wall 51d of the housing 50D includes a fixing portion 514 that protrudes from the outer surface. The fixed portion 514 has a flat surface on the upper surface, and the sensor substrate 482 is brought into contact with the upper surface of the fixed portion 514 to hold the light receiving surface of the light receiving sensor 481 at a position shifted outward from the outer surface of the side wall 51d. be able to.

  The effect of the housing 50D of the present embodiment will be described with reference to the drawings. FIG. 11 is a view showing a state in which the side wall of the housing of the scanning optical device shown in FIG. 10 is deformed by an external force. The scanned light beam is incident on the light receiving sensor 481, and when the side wall 51d is deformed, a part of the scanned light beam is irradiated on the inner surface of the detection opening 511 and reflected by the inner surface of the detection opening 511. The light beam thus irradiated is irradiated to the light receiving sensor 481 side. As indicated by a broken line in FIG. 11, when the sensor substrate 481 is attached so as to be in contact with the outer surface of the side wall 51d, the light beam reflected by the inner surface of the detection opening 511 may enter the light receiving sensor 481. When such a light beam reflected by the inner surface of the detection opening 511 is incident on the light receiving sensor 481, it may cause erroneous detection.

  Therefore, in the configuration in which the scanned light beam is incident on the light receiving sensor 481, the inner surface of the detection opening 511 is fixed by fixing the sensor substrate 482 so that the distance from the detection opening 511 to the light receiving surface of the light receiving sensor 481 is increased. It is possible to suppress the light beam reflected by the light incident on the light receiving sensor 481. This makes it possible to accurately detect the scanning start position and form an electrostatic latent image with high accuracy. The distance between the side surface 51d and the sensor substrate 482 can be, for example, about 1 mm to 2 mm, but is not limited thereto.

(Fourth embodiment)
Another example of the scanning optical device according to the present invention will be described with reference to the drawings. FIG. 12 is an enlarged cross-sectional view of a mounting portion of still another example of the light receiving portion of the scanning optical apparatus according to the present invention. As shown in FIG. 12, the housing 50E used in the scanning optical device 40 has the same configuration as that of the housing 50 of the first embodiment except that a structure 56 is provided instead of the wall portion 55. . Therefore, substantially the same parts are denoted by the same reference numerals, and detailed description of the same parts is omitted.

  As shown in FIG. 12, the housing 50E includes a wall body portion 561 having a surface facing the inner surface of the side wall 51e, and a connection portion 562 that is a wall body that connects the wall body portion 561 and the side wall 51e. Yes. The housing 50E reinforces the side wall 51e with a structure 56 including a wall body portion 561 and a connection portion 562. Since the wall portion 561 and the connection portion 562 intersect with each other, and the connection portion 562 and the side wall 51e also intersect, the reinforcing effect is higher than the case where reinforcement is performed with one wall portion. That is, the side wall 51e is not easily deformed by an external force.

  In FIG. 12, the side wall 51e, the wall body part 561, and the connection part 562 are connected so as to have an H cross section, but the present invention is not limited to this, and the wall body part 561 is connected to the side wall 51e. If it is formed so that it may be arranged, it is not limited to the H section.

  In each of the embodiments described above, the light receiving sensor receives the light beam at the scanning start position, but is not limited thereto, and may receive the light beam at the scanning end position. Alternatively, the light beam at both the scanning start position and the scanning end position may be received. The detection position of the light beam can be adjusted according to the position of the detection mirror group.

  Note that, as an image forming apparatus in which the scanning optical device 40 according to the present invention is used, a color digital multifunction peripheral is taken as an example, but the present invention is not limited to this. For example, a printer that forms an image based on image data from an external device such as a PC, and a facsimile that transmits image data using a telephone line can also be used.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this content. The embodiments of the present invention can be variously modified without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 10 Printer part 11Y, 11M, 11C, 11K Photoconductor drum 111 Charger 112 Developing device 113 Transfer roller 114 Cleaning part 12Y, 12M, 12C, 12K Toner hopper 13Y, 13M, 13C, 13K Toner bottle 14 Intermediate transfer belt 141 Drive roller 142 driven roller 143 tension roller 15 secondary transfer roller 16 fixing unit 17 cleaning blade 20 image reader unit 30 sheet feeding unit 31 sheet feeding tray 32 sheet feeding roller 33 registration roller 40 scanning optical device 41Y, 41M, 41C, 41K light source 42 Meter lens 43Y, 43M, 43C, 43K Reflective member 43R Adjustment mirror 44 Deflector 441 Polygon mirror 442 Deflection motor 45 Optical elements 46Y, 46M, 46C, 46K Scanning reflection units 50, 50B 50C, 50D, 50E Housing 51, 51b, 51c, 51d, 51e Side wall 511 Detection opening 512 Fixing part 513 Screw hole 514 Fixing part 52 Holding part 53 Reflection fixing part 54 Partition part 55, 55b, 55c, 55d Wall part 56 Structure 561 Wall part 562 Connection part

Claims (8)

A scanning optical device that scans a light beam applied to an irradiation target surface,
A scanning optical system that scans the light beam and a light receiving unit that receives the light beam on a light receiving surface are disposed,
The housing is
Side walls provided on at least a part of the outer periphery;
A light passage portion formed on the side wall so that at least one light beam at the start or end of scanning passes;
A fixing portion that is provided outside the side wall and that fixes the light receiving portion so that a light beam that has passed through the light passing portion is incident on the light receiving surface;
A structure connected to the side wall,
The scanning optical device in which the structure is provided on the opposite side across the fixed part and the side wall or between the fixed part and the light passing part.   2. The scanning optical device according to claim 1, wherein the light passing portion is an aperture hole formed so that a projected shape in the light beam passing direction is larger than a projected shape of the light receiving surface of the light receiving portion in the light beam passing direction. . A scanned light beam is incident on the light receiving surface,
The scanning optical device according to claim 2, wherein the structure is provided so as to intersect a scanning plane of a light beam incident on the light receiving surface.   The scanning optical device according to claim 1, wherein the structure is formed so as not to cross an optical path of a light beam incident on the light receiving surface.   5. The scanning optical device according to claim 1, wherein the fixing unit fixes the light receiving unit so that the light receiving surface is shifted outward from the outer surface of the side wall in the traveling direction of the light beam. 6.   The scanning optical device according to claim 1, wherein the structure is a wall.   The scanning optical device according to claim 6, wherein the structure is a rib.   The scanning according to any one of claims 1 to 5, wherein the structure includes a wall body portion having a surface facing the side wall, and a connection portion connecting the side wall and the wall body portion. Optical device.