JP2004287292A - Light scanning device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light scanning device in which the position of a light source is not deviated even when a harness is mounted or removed and to provide an image forming device equipped with the light scanning device. <P>SOLUTION: The light scanning device 10 has a first substrate 80 on which a light emitting element 60 and its driving circuit 58 are mounted and is fitted to a casing 90 which is fixed on the main body of an image forming device 200, a second substrate 120 on which a connector 124 which connects the harness 190 from the main body of the image forming device 200 is mounted and fitted on the casing 90 separately from the first substrate 80, and an elastically deformable connecting member 110 which electrically connects a terminal 116 of the first substrate 80 and a terminal 122 of the second substrate 120. The light scanning device 10 is disposed in the housing 192 of the image forming device 200 and the connector 124 is exposed from an opening part 194 provided on the housing 192. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical scanning device mounted on a laser copying machine, a laser beam printer, or the like, and an image forming apparatus including the same, and more particularly, to a light source mounting structure in the optical scanning device.
[0002]
[Prior art]
In recent years, image forming apparatuses that use laser light for an image forming process, such as a laser printer, have become widespread. In this type of image forming apparatus, a laser beam is applied to an image carrier such as a photosensitive material or a photosensitive member. An optical scanning device that forms an image (latent image) on an image carrier by scanning is often used.
[0003]
Further, in such an image forming apparatus, there is a strong demand for speeding up image formation. As a means for realizing this, for example, an image carrier is simultaneously scanned by a plurality of laser beams to form an image. Multi-beam is adopted. As means for achieving the multi-beam formation, a laser scanning device using a VCSEL (Vertical Cavity Surface Emitting Laser-Diode) as a light source, in which a plurality of light emitting units can be easily arranged on one semiconductor laser chip. (For example, see Patent Document 1).
[0004]
In such a laser scanning device, a semiconductor laser device on which a semiconductor laser chip is mounted is attached to a support structure on which an imaging optical system and a deflector are mounted, and laser light emitted from the semiconductor laser device forms an image. An image is formed as a beam spot on the image carrier by the optical system and the deflector, and the image carrier is scanned. In this laser scanning device, the direction (optical axis direction) of the light beam emitted from the semiconductor laser chip affects the optical characteristics of the imaging optical system, so that the relative position adjustment of the semiconductor laser chip with respect to the imaging optical system can be performed. Performed with micron accuracy.
[0005]
Further, as a conventional semiconductor laser used as a light source in the above-described laser scanning device, for example, there is one shown in FIG. A block-shaped support 304 is fixed to the semiconductor laser 300 at the center of the surface of a disk-shaped stem 302. One end of the support 304 has an edge-emitting type via a heat sink 306. A semiconductor laser chip (hereinafter, sometimes referred to as “LD”) 308 is attached. Further, a photodiode (hereinafter, referred to as “MPD”) 310 for monitoring the amount of light is fixed to the surface of the stem 302 so as to face the LD 308.
[0006]
The semiconductor laser 300 is provided with a cap 312 so as to cover the surface of the stem 302, and a window 314 through which laser light B passes is opened at the center of the top surface of the cap 312. Further, the semiconductor laser 300 is provided with a plurality of electrode terminals 316 so as to penetrate the stem 302, and these electrode terminals 316 are connected to the electronic devices such as the LD 308 and the MPD 310 on the stem 302 by bonding wires 318. Parts are connected. Thereby, electronic components such as the LD 308 and the MPD 310 are connected to a drive control circuit (not shown) via the bonding wires 318 and the electrode terminals 316 (for example, see Patent Document 2).
[0007]
When mounting the semiconductor laser 300 thus configured on a laser scanning device, first, the semiconductor laser 300 is fixed on a circuit board (not shown) using the back surface of the stem 302 as a reference surface, and then the semiconductor laser 300 is fixed. Is press-fitted and fixed in a holder member (not shown) for attaching to the laser scanning device. The holder member is provided with an abutment surface serving as a reference at the time of attachment to the laser scanning device, and a reference light source attachment portion of the laser scanning device to which the semiconductor laser 300 is attached is also provided with a reference attachment surface. The holder member holding the semiconductor laser 300 is fixed to the light source mounting portion with screws or the like in a state where the abutting surface is in contact with the mounting surface.
[0008]
The mounting structure of the semiconductor laser for mounting the semiconductor laser on the light source mounting portion of the optical scanning device includes, for example, a reference surface of a holder member holding the semiconductor laser (perpendicular to the optical axis of laser light emitted from the semiconductor laser). The light source side reference surface processed so as to be a flat surface to be processed is referred to as the reference surface of the light source mounting portion (the mounting reference surface processed so as to be a plane orthogonal to the optical axis of laser light emitted from the semiconductor laser). After adjusting the optical axis position of the laser emitted from the semiconductor laser along the optical axis direction and the direction perpendicular to the optical axis in a state in which the semiconductor laser is brought into contact with the semiconductor laser, the fixing screw inserted into the through hole of the holder member is attached to the light source mounting portion. There is one that fixes a semiconductor laser to a light source mounting portion via a holder member by screwing into a screw hole formed in the device (for example, Patent Literature 3, Patent Literature 3). Reference).
[0009]
[Patent Document 1]
JP-A-5-294005 (FIG. 1)
[Patent Document 2]
JP-A-9-102650 (FIG. 23)
[Patent Document 3]
JP-A-5-297303 (FIG. 4)
[Patent Document 4]
JP-A-7-168109 (FIG. 2)
[0010]
[Problems to be solved by the invention]
However, in the above laser scanning device, when the emission position of the laser light from the laser light source is before or after a predetermined position along the optical axis direction (depth direction), the error increases several hundred times on the photoconductor. It is magnified and appears as an error in the focal position of the laser beam with respect to the photoconductor surface (hereinafter, referred to as “focus difference”). That is, a focus difference enlarged according to the vertical magnification of the imaging optical system occurs.
[0011]
Specifically, for example, when the beam diameter on the photoreceptor is 50 μm, the depth of focus is 4 mm, and the field curvature is 2 mm, the allowable focus difference in the depth direction is 2 mm. At this time, assuming that the longitudinal magnification in the laser scanning device is 200 times, an allowable difference in the optical axis direction of the emission position of the laser light source is 10 μm or less.
[0012]
If this relationship is applied to a semiconductor laser device using a two-beam laser array having a light emitting point interval of 14 μm as a light source, the inclination of the light source corresponding to the positional difference (10 μm or less) along the depth direction between the two light emitting points. Is allowed up to 35.5 ° (= ATAN (10/14)). On the other hand, in a semiconductor laser device using a multi-beam array as a light source in which the number of light emitting points becomes several to several tens, for example, if the distance between the light emitting points at both ends of the laser array is 200 μm, In order to make the error along the depth direction of 10 μm or less, the inclination of the light source must be 2.9 ° (= ATAN (10/200)) or less.
[0013]
However, the semiconductor laser 300 shown in FIG. 21 has a structure in which the LD 308 is fixed to one side surface (mounting surface) of the support base 304 via the heat sink 306, so that the direction orthogonal to the mounting surface is the Y direction. When the optical axis direction of the imaging optical system is the Z direction, and the direction orthogonal to the Y direction and the Z direction is the X direction, the inclination error of the LD 308 along the YZ plane is determined by using the LD 308 with respect to the mounting surface. When the LD 308 is attached to the support 304, the inclination error of the LD 308 along the ZX plane does not exist as a reference surface. Easy to grow. Such a problem can similarly occur when a surface-emitting type LD is used as a light source in the semiconductor laser device shown in FIG.
[0014]
On the other hand, in the mounting structure of the semiconductor laser as described above (hereinafter sometimes simply referred to as “mounting structure”), the semiconductor laser as the light source is fixed after the positioning adjustment, but the flatness of the light source side reference surface of the holder member is adjusted. There is a difference in the flatness of the mounting reference surface of the light source mounting part, so that one reference surface follows the other reference surface at the time of fixing, and even if the position of the semiconductor laser is accurately adjusted, the position of the semiconductor laser at the time of fixing is And the like fluctuates.
[0015]
That is, as shown in the side sectional view of FIG. 22, for example, the conventional mounting structure 320 is provided with a plate-shaped laser driving substrate 322 for holding the semiconductor laser 300, and the semiconductor laser is connected via the laser driving substrate 322. A light source mounting part 330 to which the light source 300 is mounted is provided on a housing (not shown) of the optical scanning device. Here, the laser driving substrate 322 has one surface serving as a light source-side reference surface 324, and the light source mounting portion 330 abuts on the light source-side reference surface 324 of the laser driving substrate 322 to contact the semiconductor laser 300. The mounting reference surfaces 326 and 328 for positioning are formed in a planar shape, and the window 332 through which the laser light B emitted from the semiconductor laser 300 passes is penetrated.
[0016]
In such a mounting structure 320, as shown in FIG. 22D, the laser is driven while the light source side reference surface 324 of the laser driving substrate 322 and the mounting reference surfaces 326, 328 of the light source mounting portion 330 are respectively kept flat. Ideally, the semiconductor laser 300 is fixed via the drive substrate 322. However, the light source side reference surface 324 of the laser drive board 322 and the mounting reference surfaces 326, 328 of the light source mounting portion 330 have respective shape errors due to manufacturing errors of each component.
[0017]
Therefore, as shown in FIG. 22A, for example, when a shape error (inclination) occurs on one side (right side) of the mounting reference surface 328, the position adjustment of the semiconductor laser 300 is performed as shown in FIG. As shown in the figure, the operation is performed in a state where the light source side reference surface 324 is in contact with the high point portion of the mounting reference surface 328. That is, in this state, the position adjustment of the semiconductor laser 300 is performed while the light source side reference surface 324 is pressed against the mounting reference surfaces 326 and 328 by an assembling jig (not shown) or the like.
[0018]
However, after the position adjustment of the semiconductor laser 300 is completed, as shown in FIG. 22C, the laser driving substrate 322 is fixed by the screw 334 serving as a fastening member. The laser drive board 322 and the light source mounting part 330 are deformed in one or both of them (mainly the laser drive board 322 in this case) because they are fastened so as to completely coincide with the surface 328. That is, there is a problem that the semiconductor laser 300 held by the laser drive substrate 322 is in a different posture from that at the time of adjustment.
[0019]
In particular, the relative positional relationship between the semiconductor laser 300 and the collimator lens (not shown) arranged in the housing of the optical scanning device requires extremely strict accuracy, and the positional deviation is caused by a shock after manufacturing or the like. If this occurs, the desired performance cannot be obtained, so the laser drive substrate 322 needs to be firmly fixed to the light source mounting part 330. Therefore, in such a conventional mounting structure 320, problems such as difficulty in position adjustment at the time of assembling, deterioration of adjustment accuracy, and an increase in adjustment man-hours are likely to occur.
[0020]
In order to solve such a problem, a mounting structure as shown in an exploded view of FIG. 23 has been considered. That is, the laser package 338 in which the laser array 336 is incorporated is attached to the laser drive substrate 322, and the laser package 338 is applied to the projecting attachment reference surface 342 of the housing 340 to perform positioning in the optical axis direction. The laser driving substrate 322 is pressed and held by the protruding mounting reference surface 342 of the housing 340 by the elastic connecting member 344. With such a configuration, the package member (laser package) 338 and the semiconductor laser chip (laser array) 336 can be attached to a predetermined position of the light source attachment portion without causing a tilt error.
[0021]
However, in recent years, a high-speed and high-resolution optical scanning device has been demanded, and in order to satisfy this demand, an optical scanning device having a large number of laser light emitting sources has been required. Accordingly, the number of harnesses from a control unit (not shown) of the image forming apparatus for sending image data to the optical scanning device has been increasing.
[0022]
Therefore, even if the above-described configuration in which the package member 338 and the semiconductor laser chip 336 are attached to the predetermined position of the light source attachment portion without tilt error is adopted, when the optical scanning device is provided in the image forming device, When attaching or detaching the harness from the control unit to the laser driving substrate 322, there is a problem that an external force is applied to the laser driving substrate 322, and the package member 338 and the semiconductor laser chip 336 are shifted and tilted from an ideal position. When such a tilt error occurs, as shown in FIG. 20, a jagged edge occurs in the main scanning direction, a white streak (hereinafter, referred to as “Banding”) occurs in the main scanning direction, and the image quality is reduced. Lower it.
[0023]
In view of the above problems, the present invention provides an optical scanning device in which a package member and a semiconductor laser chip are not displaced even when a harness is attached and detached, and an image forming apparatus including the same. With the goal.
[0024]
[Means for Solving the Problems]
In order to achieve the above object, an optical scanning device according to claim 1 of the present invention includes a first light emitting element and a driving circuit for the light emitting element, the first light emitting element being mounted on a housing fixed to a main body of the image forming apparatus. A board and a connector for connecting a harness from the image forming apparatus main body are mounted, the second board is separated from the first board, and is attached to the housing, and a terminal of the first board is provided. An elastically deformable connection member that electrically connects the terminal of the second substrate to the terminal.
[0025]
According to the first aspect of the present invention, the first substrate on which the light emitting element and its driving circuit are mounted is separated from the second substrate on which the connector for connecting the harness is mounted, and both are elastically deformable connecting members. Even if the harness is attached to and detached from the connector of the second substrate, the external force at the time of attachment and detachment is absorbed by the connecting member and does not act on the first substrate. . Therefore, the first substrate does not deviate from the ideal position, and the light emitting element does not change in tilt.
[0026]
Conventionally, a configuration in which a light emitting element and a driving circuit thereof are mounted on separate substrates and alignment is adjusted by moving the light emitting element side has been known. Since it is formed on a separate substrate, there is a problem that it is weak against noise, and the quality for high-speed and high-resolution image quality is reduced. However, in the present invention, since a driving circuit for a light emitting element is also provided on a substrate on which the light emitting element is mounted, and the substrate is configured to be adjustable in alignment, it is strong against noise and provides high quality image quality. Can be.
[0027]
The optical scanning device according to claim 2, wherein the first substrate is provided with a light emitting element and a driving circuit thereof, and is mounted on a housing fixed to the image forming apparatus main body, and a harness from the image forming apparatus main body. And a second board that is separated from the first board and is attached to the housing and that is elastically deformable. The second board is provided on the second board. And a fixed terminal electrically connected to the terminal.
[0028]
According to the second aspect of the present invention, the first substrate on which the light emitting element and its driving circuit are mounted is separated from the second substrate on which the connector for connecting the harness is mounted, and the second substrate is elastically deformed. It is configured so that both are electrically connected, so even if the harness is attached to or detached from the connector of the second board, the external force at the time of attachment / detachment is absorbed by the second board, It does not act on one substrate. Therefore, the first substrate does not deviate from the ideal position, and the light emitting element does not change in tilt.
[0029]
In addition, since the connecting member as described in claim 1 (an additional member for connecting the both) is not required, the number of terminals mounted on the first substrate and the second substrate can be reduced. Therefore, assemblability can be improved, and an optical scanning device that is more resistant to noise than the configuration described in claim 1 can be provided.
[0030]
Furthermore, an optical scanning device according to a third aspect is characterized in that, in the optical scanning device according to the first aspect, the connecting member is bent and formed twice or more.
[0031]
According to the third aspect of the present invention, since the elastically deformable connecting member is formed by being bent twice or more, the movable allowable amount (degree of freedom) can be improved, and the first substrate and the second substrate can be improved. In the position adjustment, independent adjustment can be further simplified. Therefore, it is possible to provide an optical scanning device with good workability and maintainability.
[0032]
An optical scanning device according to a fourth aspect is the optical scanning device according to the second aspect, wherein the second substrate is bent and formed twice or more.
[0033]
According to the fourth aspect of the present invention, since the elastically deformable second substrate is formed by being bent at least twice, the movable allowable amount (degree of freedom) can be improved, and the first substrate and the second substrate can be formed. In the position adjustment of the substrate, independent adjustment can be further simplified. Therefore, it is possible to provide an optical scanning device with good workability and maintainability.
[0034]
According to a fifth aspect of the present invention, in the optical scanning device according to any one of the first to fourth aspects, the first substrate is attached to the housing so as to be adjustable in position. Features.
[0035]
According to the fifth aspect of the present invention, since the first substrate is attached to the housing so as to be position-adjustable, the light-emitting element can be easily fixed at an ideal position.
[0036]
An optical scanning device according to a sixth aspect is characterized in that, in the optical scanning device according to any one of the first to fifth aspects, the light emitting elements are arranged in an array.
[0037]
According to the sixth aspect of the present invention, since the light emitting elements are arranged in an array, it is possible to provide a higher quality image.
[0038]
According to a seventh aspect of the present invention, in the optical scanning device according to the sixth aspect, a sensor for detecting an inclination angle of the light emitting elements arranged in the array with respect to a sub-scanning direction, and a detection by the sensor are provided. A rotation adjusting unit configured to adjust the rotation of the first substrate based on the result.
[0039]
According to the seventh aspect of the present invention, the inclination angle of the light emitting elements (light sources) arranged in an array with respect to the sub-scanning direction is detected by a sensor, and the first substrate is rotationally adjusted based on the detection result. It is possible to provide a high-quality optical scanning device with as little unevenness as possible.
[0040]
On the other hand, an image forming apparatus according to an eighth aspect of the present invention includes a housing in which the optical scanning device according to any one of the first to seventh aspects can be disposed, and a second hole formed in the housing, and And an opening for exposing the connector mounted on the substrate.
[0041]
According to the eighth aspect of the present invention, since the opening for exposing the connector is formed in the housing in which the optical scanning device is disposed, the harness can be connected to the connector from outside the housing. Therefore, it is possible to provide an image forming apparatus that can be reduced in size by at least the amount of the harness and has good workability. In other words, in order to meet the demand for high-speed and high-resolution, the number of light-emitting elements has increased, which has led to an increase in the number of harnesses to be connected and an increase in the number of connectors for connecting harnesses. Was housed in the housing. For this reason, since the harness was also housed in the housing, the size of the image forming apparatus was increased, and the workability was deteriorated. According to the invention of claim 8, this can be solved.
[0042]
In the image forming apparatus according to a ninth aspect, in the image forming apparatus according to the eighth aspect, the second substrate is attached to the housing of the optical scanning device so as to be position-adjustable. And
[0043]
According to the ninth aspect of the present invention, since the position of the second substrate can be adjusted, even if the optical scanning device is disposed slightly shifted from the opening of the housing, the connector mounted thereon is exposed from the opening. be able to. That is, even when the configuration in which the height of the housing is reduced is adopted, the connector can be exposed from the opening, so that the size of the image forming apparatus can be reduced.
[0044]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, an outline of an optical scanning device provided in an image forming apparatus will be described. The optical scanning device described in the present embodiment is a laser scanning device to which a semiconductor laser device is applied as a light source device.
[0045]
[Overview of laser scanning device]
As shown in FIG. 1, a laser scanning device 10 scans a drum-shaped photoconductor 12 with a laser beam B modulated by an image signal, and forms an electrostatic latent image on the photoconductor 12. Yes, it is applied to an image forming apparatus such as a laser printer, a copying machine, etc., on which an image is formed by an electrophotographic process.
[0046]
The laser scanning device 10 includes a semiconductor laser 16 as a light source device of the laser beam B. The semiconductor laser 16 has a built-in surface emitting laser array 60 (see FIG. 3) as a multi-beam light source. When driven, the laser array 60 emits a plurality of laser beams B having a substantially Gaussian distribution (however, only one laser beam B is shown in FIG. 1). The laser light B emitted from the laser array 60 becomes a light beam having a substantially uniform divergence angle in each of the main scanning direction M and the sub-scanning direction S.
[0047]
Further, the laser scanning device 10 includes a collimator lens 18, a slit member 20 for shaping a light beam, a cylindrical lens 22, and a half mirror 24 along the optical path of the laser light B emitted from the semiconductor laser 16. It is arranged in order from. Here, the collimator lens 18 is arranged such that the distance between the collimator lens 18 and the laser array 60 along the optical axis of the laser beam B matches the focal length of the collimator lens 18, and thereby the collimator lens 18 is The transmitted light beam becomes substantially parallel light. Then, the laser light B is shaped into a predetermined cross-sectional shape by passing through the slit of the slit member 20, and is incident on the cylindrical lens 22 having a curvature along the sub-scanning direction S.
[0048]
The half mirror 24 transmits about 30% of the total light amount of the laser light B transmitted through the cylindrical lens 22 and reflects the remaining laser light B toward the rotary polygon mirror 26. The back side of the half mirror 24 is configured as a cylindrical lens having a curvature along the main scanning direction M, and the laser light B transmitted through the cylindrical lens 22 and the half mirror 24 is transmitted to the sub scanning direction S and the main scanning direction M. The light is condensed to form a light spot on a light receiving portion of a photodiode (MPD) 28 for monitoring the amount of light.
[0049]
The rotary polygon mirror 26 is formed in the shape of a regular polygonal prism, and a plurality of planes on the outer peripheral side thereof are each a reflection / deflection surface 30. Further, a deflection driving means (not shown) composed of a stepping motor or the like is connected coaxially to the rotary polygon mirror 26, and the rotary polygon mirror 26 is rotated about the axis by the torque transmitted from the deflection drive means. It rotates at a constant angular velocity in one direction. The laser beam B reflected by the half mirror 24 is converged along the sub-scanning direction S on the reflection deflection surface 30 by the lens power of the cylindrical lens 22. Then, the rotary polygon mirror 26 reflects the laser beam B by the reflection / deflection surface 30, and deflects the laser beam B so that the laser beam B moves at a constant angular velocity along the main scanning direction M.
[0050]
Further, the laser scanning device 10 is provided with a pair of Fθ lenses 32 and 34 along the direction in which the laser beam B is deflected by the rotary polygon mirror 26. Lenses 32 and 34 are formed in elongated rod shapes along the main scanning direction M, respectively. The Fθ lenses 32 and 34 converge the laser light B reflected by the rotary polygon mirror 26 along the main scanning direction M and generate the laser light. The movement of B in the main scanning direction M is converted from a constant angular velocity to a constant linear velocity.
[0051]
The laser beam B transmitted through the Fθ lenses 32 and 34 has its optical path bent in a substantially “U” shape by the first cylindrical mirror 36 and the plane mirror 38, and is further reflected by the second cylindrical mirror 40 toward the photoconductor 12. You. The laser beam B reflected by the second cylindrical mirror 40 passes through the dust-proof window glass 42 and reaches the outer peripheral surface of the photoconductor 12. Note that the first cylindrical mirror 36 and the second cylindrical mirror 40 have optical power for converging the laser beam B along the sub-scanning direction S.
[0052]
Further, in the laser scanning device 10, the reflection / deflection surface 30 of the rotary polygon mirror 26 and the outer peripheral surface of the photoreceptor 12 have a substantially conjugate relationship, whereby the deflection direction of the rotary polygon mirror 26 varies (surface tilt). The displacement of the light spot along the sub-scanning direction S on the photoconductor 12 caused by the above is corrected. The curvature of the collimator lens 18, the cylindrical lens 22, the first cylindrical mirror 36, and the second cylindrical mirror 40 in the sub-scanning direction S is determined by the beam interval along the sub-scanning direction S on the photoconductor 12, The beam spacing at a position several millimeters away from 12 is set to have a telecentric relationship equal to each other.
[0053]
The photoreceptor 12 is formed in a substantially columnar shape elongated in the axial direction, and has an outer peripheral surface serving as a photosensitive surface 14 responsive to the laser beam B. The photoconductor 12 is supported so that its axial direction coincides with the main scanning direction M of the laser scanning device 10. That is, in the laser scanning device 10, the laser beam B emitted from the semiconductor laser 16 converges as a light spot on the photoconductor 12, and this light spot moves on the photoconductor 12 in the main scanning direction M and is mainly moved. A latent image is recorded along the scanning line.
[0054]
Further, a sub-scanning driving unit (not shown) is connected to the photoconductor 12, and the sub-scanning driving unit rotates the photoconductor 12 by a predetermined amount in synchronization with completion of one main scan on the photoconductor 12. Let it. As a result, the portions of the photoconductor 12 that differ by a distance corresponding to the pixel density along the sub-scanning direction (circumferential direction) S are sequentially main-scanned by the laser light B, and a two-dimensional latent image is formed on the photoconductor 12. It is a configuration that is being formed.
[0055]
In the laser scanning device 10, a plane mirror 44 is disposed on the optical path of the laser beam B reflected by one end of the plane mirror 38 to the outside of the photoconductor 12, and the laser beam reflected by the plane mirror 44 is disposed. On the optical path B, a cylindrical lens 46 and a synchronization sensor 48 are arranged in order from the plane mirror 44 side. Therefore, the laser beam B reflected by one end of the plane mirror 38 is further reflected by the plane mirror 44 and enters the cylindrical lens 46, and forms an image on the light receiving section of the synchronous sensor 48 by the cylindrical lens 46.
[0056]
Simultaneously with the incidence of the laser beam B, the synchronous sensor 48 outputs an SOS signal to a video controller 52 (see FIG. 2) described later, and based on the SOS signal, the video controller 52 The writing timing along M and the movement (rotation) timing of the photoconductor 12 in the sub-scanning direction S are determined.
[0057]
FIG. 2 shows a configuration of a drive / control circuit in the laser scanning device 10 to which the semiconductor laser 16 is applied. The drive / control circuit 50 includes a video controller 52, a laser array control unit 54, and a laser array drive circuit 58. The video controller 52 is connected to the synchronization sensor 48, and the laser array controller 54 is connected to the MPD 28. Further, the laser array drive circuit 58 outputs a drive signal to the laser array 60 and controls the emission of the laser beam B by the laser array 60. The laser array controller 54 and the laser array drive circuit 58 are provided on a printed wiring board 80 (see FIG. 5) described later.
[0058]
[Configuration of semiconductor laser]
Next, the configuration of the semiconductor laser 16 will be described. As shown in FIGS. 3 and 4, the semiconductor laser 16 uses a VCSEL (Vertical Cavity Surface Emitting Laser-Diode) 60 as a semiconductor laser chip that emits laser light B. The laser array 60 is fixed on a package member 68, and 32 laser light emitting portions 64 are arranged in a matrix on a surface portion 62. The laser light B is emitted from each of the laser light emitting portions 64 perpendicularly to the surface portion 62.
[0059]
As shown in FIG. 3, in the laser array 60, 32 laser light emitting units 64 are arranged so as to be shifted from each other by a predetermined pitch along the sub-scanning direction (the direction of arrow S). The pitch of 64 is set corresponding to the interval between scanning lines on the photoconductor 12 (see FIG. 1), that is, the resolution along the sub-scanning direction S. By the way, in the present embodiment, the magnification of the imaging optical system is set so that the pitch between the laser light emitting portions 64 in the laser array 60 is 7 μm and the scanning line interval on the photoconductor 12 is 10.6 μm. As a result, an image of 2400 dpi can be formed on the photoconductor 12. Further, in the laser scanning device 10, the delay time of the image signal is adjusted according to the position of each laser light emitting unit 64 in the main scanning direction (the direction of the arrow M), so that the laser light is emitted along the main scanning direction M on the photoconductor 12. The deviation of the writing timing is corrected.
[0060]
As shown in FIG. 4, the semiconductor laser 16 includes a plate-shaped laser array 60 and a package member 68 that holds the laser array 60. In the laser array 60, a front surface portion 62 and a rear surface portion 66 along the thickness direction are each formed in a planar shape. Since the laser array 60 is configured as a surface emitting laser (VCSEL), the laser emitted from the laser emitting section 64 is formed so that the front surface portion 62 and the back surface portion 66 are accurately parallel to each other. It has the characteristic that the optical axis of the light B is accurately maintained perpendicular to the surface portion 62.
[0061]
The package member 68 is formed in a flat block shape along the optical axis direction of the laser beam B, and has a storage chamber 70 that is concavely recessed at the center of the surface. The bottom surface of the storage chamber 70 is precisely processed so as to have a sufficiently smooth flat surface, and serves as a first reference surface 72 on which the laser array 60 is mounted. The laser array 60 is placed and fixed on the central portion of the first reference surface 72 with its back surface portion 66 abutting on the first reference surface 72. Even when an intermediate layer made of an adhesive or the like is interposed between the back surface portion 66 of the laser array 60 and the first reference surface 72, the thickness of such an intermediate layer is sufficiently small and uniform. It is formed so that
[0062]
On the surface of the package member 68, a second reference surface 74 is provided on the outer peripheral side of the storage chamber 70, and the second reference surface 74 is a sufficiently smooth plane like the first reference surface 72. And is processed with high accuracy so as to be parallel to the first reference surface 72. Accordingly, in a state where the laser array 60 is fixed to the package member 68, the surface portion 62 of the laser array 60, the first reference surface 72, and the second reference surface 74 of the package member 68 are accurately parallel to each other. The optical axis of the laser beam B emitted from the laser emitting section 64 is accurately perpendicular to the first reference plane 72 and the second reference plane 74.
[0063]
Here, the package member 68 is made of Al ₂ O ₃ , SiO ₂ , TiO ₂ Is formed by, for example, grinding using a ceramic such as Package member 68 is Al ₂ O ₃ , SiO ₂ , TiO ₂ By using such ceramics, when used as a light source device of the laser scanning device 10, good characteristics such as strong resistance to dew condensation, low conductivity, and strong electrostatic noise can be obtained. In general, ceramics are suitable as a material of the package member 68 because accuracy can be easily obtained on the order of submicron due to the characteristics of the material.
[0064]
As shown in FIG. 4, the laser array 60 fixed (mounted) on the package member 68 includes a connection circuit including printed wiring (not shown) provided on the package member 68 side by a plurality of bonding wires 76. Is connected to Further, a dustproof glass 78 made of a transparent material is fitted into an opening on the top surface side of the storage room 70, thereby forming a space sealed from the outside in the storage room 70.
[0065]
As shown in FIG. 5, the semiconductor laser 16 is mounted on a predetermined mounting portion 82 of a printed wiring board 80 formed in a plate shape, and a terminal portion of a connection circuit of the package member 68 is placed on the printed wiring board 80. The terminal of the formed printed wiring is connected via a cable, solder, or the like. A laser array drive circuit 58 is mounted on the printed wiring board 80. Thereby, the laser array 60 of the semiconductor laser 16 and the laser array drive circuit 58 are electrically connected to each other via the printed wiring board 80. Further, the semiconductor laser 16 is fastened and fixed to the printed wiring board 80 by a plurality of screws (not shown), so that the semiconductor laser 16 It is connected and fixed to the substrate 80 with sufficient strength.
[0066]
[Semiconductor laser mounting structure]
Next, the mounting structure of the semiconductor laser 16 will be described. As shown in FIG. 5, the semiconductor laser 16 as a light source device is attached to a housing (optical box) 90 on which the imaging optical system of the laser scanning device 10 is mounted. The image forming optical system referred to here is a set of optical components such as a lens and a mirror for forming an image on the photoconductor 12 using the laser beam B emitted from the semiconductor laser 16 as a light spot. 1 includes the collimator lens 18, the slit member 20, the cylindrical lens 22, the half mirror 24, and the Fθ lenses 32 and 34 shown in FIG. In addition, the rotating polygon mirror 26, the synchronization sensor 48, the MPD 28, and the like are mounted on the housing 90. The housing 90 accommodates and supports optical components constituting the imaging optical system, and also controls the optical components. And a dustproof space for preventing foreign matter such as dust from adhering thereto.
[0067]
As shown in FIG. 5, the housing 90 is provided with a light source mounting portion 92 for mounting the semiconductor laser 16 on the outer surface thereof. In the light source mounting portion 92, a laser inlet 94 for passing the laser light B into the housing 90 is formed at the center portion, and protrudes from the side surface of the housing 90 at a peripheral portion of the laser inlet 94. Support base 96 is provided as described above. In addition, two non-penetrating (or penetrating) screw holes 98 are provided on the outer peripheral side of the support base 96 at evenly upper and lower positions around the optical axis. Two holes 108 are provided at equal positions in the vertical direction. Therefore, the elastic connection member 100 is fixed to the housing 90 by inserting the screw 88 into the screw hole 108 and screwing it into the screw hole 98.
[0068]
The elastic connecting member 100 is formed of a synthetic resin, and in order to enhance the elasticity effect, a slit 102 is provided at an equal position on the left and right with respect to the optical axis center. Screw holes 104 are provided at equal positions on the left and right sides of the optical axis. A rectangular opening 106 for allowing the semiconductor laser 16 is formed in the center. Further, the support base 96 of the light source mounting portion 92 is processed so that the front end surface thereof is a sufficiently smooth plane, and the front end surface of the support base 96 is formed by a laser beam B emitted from the semiconductor laser 16. Is a reference mounting surface for determining the direction of the optical axis. The light source mounting portion 92 has a surface direction determined with reference to the optical axis of the imaging optical system mounted on the housing 90. Specifically, the incidence portion of the laser beam B of the imaging optical system It is formed with high precision so as to be orthogonal to the optical axis extended from.
[0069]
Here, if the flatness of the light source mounting portion 92 can be made sufficiently high and the inclination error in the plane direction can be made sufficiently small, the support base 96 may be integrally formed with the housing 90 with resin or the like. However, when sufficient accuracy cannot be obtained by such a molding method, for example, molding is performed using a material such as ceramic which can achieve high processing accuracy, and the inclination of the side surface of the housing 90 with respect to the optical axis is adjusted. It is provided by fixing.
[0070]
<How to mount the printed wiring board>
Next, a method of attaching the printed wiring board 80 to the housing 90 will be described. When mounting the semiconductor laser 16 on the light source mounting portion 92, first, the package member 68 facing the opening 106 was perforated on the left and right sides of the semiconductor laser 16 of the printed wiring board 80 while making contact with the support base 96. A screw 86 is inserted into each of the insertion holes 84, and the distal end of the screw 86 is screwed into the screw hole 104 of the elastic connecting member 100 by a substantially equal amount.
[0071]
Thus, the printed circuit board 80 restrained by the light source mounting portion 92 restrains the semiconductor laser 16 to the light source mounting portion 92 with the package member 68 in contact with the support base 96 (light source mounting portion 92). At this time, the two screws 86 are screwed substantially evenly into the screw holes 98 until the outer portion of the elastic connecting member 100 is slightly bent and deformed. Therefore, the package member 68 is maintained in a state where a weak frictional force is generated between the package member 68 and the light source mounting portion 92.
[0072]
Further, the laser array 60 is arranged along a plane substantially perpendicular to the optical axis of the laser array 60 mounted on the package member 68, that is, the optical axis direction with respect to the imaging optical system as the Z axis. When the scanning direction is represented by the X axis and the sub-scanning direction is represented by the Y axis, adjustment is performed along the ZX plane and the XY plane so that there is no inclination (tilt adjustment). Then, the position adjustment along the X-axis direction and the Y-axis direction (along the XY plane) of the semiconductor laser 16 and the adjustment (phase adjustment) in the rotation direction around the Z-axis are performed simultaneously.
[0073]
That is, the position adjustment along the XY plane is performed by sliding the printed wiring board 80 against the frictional force between the package member 68 and the light source mounting portion 92 while keeping the package member 68 in contact with the light source mounting portion 92. (Parallel movement). Thereby, the semiconductor laser 16 is positioned along the XY plane such that the optical axis of the laser array 60 coincides with the optical axis of the imaging optical system.
[0074]
Further, the phase adjustment about the Z axis is performed by rotating the printed wiring board 80 about the Z axis while bringing the package member 68 into contact with the light source mounting portion 92. As a result, in the semiconductor laser 16, the plurality of laser light emitting portions 64 in the laser array 60 are arranged in a predetermined direction with respect to the X axis and the Y axis. The permissible amount of the position adjustment along the XY plane and the permissible amount of the phase adjustment around the Z axis are determined by the difference between the inner diameter of the insertion hole 84 in the printed wiring board 80 and the outer diameter of the screw 86. From this, it is determined how much the inside diameter of the insertion hole 84 is enlarged with respect to the outside diameter of the screw 86.
[0075]
When the position adjustment along the XY plane and the phase adjustment about the Z axis are completed, the two screws 86 are screwed into the screw holes 104 until a predetermined fastening torque is generated, and the elastic connecting member 100 is Increase the amount of outward deflection sufficiently. As the amount of flexure increases, the frictional force between the package member 68 and the light source mounting portion 92 increases. By sufficiently increasing the frictional force, the semiconductor laser 16 moves and rotates along the XY plane. Is bound.
[0076]
As described above, the frictional force between the package member 68 and the light source mounting portion 92 has a magnitude corresponding to the fastening torque of the screw 86. Therefore, the fastening torque when the screw 86 is screwed into the screw hole 104 is appropriately adjusted. By setting, the frictional force between the package member 68 and the light source mounting portion 92 can be made sufficiently large. Thus, the semiconductor laser 16 can be easily attached to the light source attachment portion 92 of the housing 90 on which the imaging optical system is mounted, and the inclination error of the laser array 60 in the semiconductor laser 16 with respect to the optical axis of the imaging optical system. That is, the positioning error along the XY plane and the phase error around the Z axis can be sufficiently reduced.
[0077]
<How to attach the connector board>
Next, a method for attaching the connector boards 120, 130, and 140 to the housing 90 and a method for connecting the connector boards 120, 130, and 140 to the printed wiring board 80 described in Examples 1 to 3 below will be described. The connector boards 120, 130, and 140 are provided separately from the printed wiring board 80, and are connected to an image data transmission harness 190 from a control unit (not shown) of the image forming apparatus 200. I have.
[0078]
(First embodiment)
First, a first embodiment will be described. As shown in FIG. 5, a connector 124 to which the harness 190 is connected is mounted on the connector board 120. A threaded hole 126 is formed on both upper and lower sides of the connector 124, and a non-penetrated (or may be threaded) threaded hole 118 is provided in the housing 90. Therefore, the connector board 120 is fastened to the housing 90 by inserting the screw 128 into the screw hole 126 and screwing it into the screw hole 118. Another connector 122 is mounted on the connector board 120, and is used for connection with the printed wiring board 80.
[0079]
That is, a connector 116 for connection to the connector board 120 is also mounted on the printed wiring board 80, and a connector 112 connected to the connector 116 and a connection 114 mounted with the connector 114 connected to the connector 122 of the connector board 120. A member 110 is separately provided. The connecting member 110 is a cable (hereinafter, referred to as FPC) to which a rolled copper foil is adhered using a polyimide resin as a base material (heat 25 μm), and is formed of an elastic material having low rigidity.
[0080]
Therefore, when the harness 190 is attached to and detached from the connector 124, the external force acting on the connector board 120 is absorbed by the connection member (FPC) 110 and does not reach the printed wiring board 80, so that the package member 68 and the semiconductor laser 16 There is no misalignment due to the attachment / detachment of the harness 190 (the adjusted positions are not disturbed), so that the image quality does not deteriorate. Further, since the connection member (FPC) 110 is an elastic body, the position (posture) of the printed wiring board 80 can be moved to some extent even when the connector board 120 is fixed with the screws 128. I have. Therefore, the position adjustment of the printed wiring board 80 described later can be easily performed regardless of the harness 190, and the adjusted state is suitably maintained.
[0081]
(Second embodiment)
Next, a second embodiment will be described. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In the configuration of the first embodiment, the printed wiring board 80, the connector board 120, and the connecting member (FPC) 110 for connecting between the printed wiring board 80 and the connector board 120 are required. In the second embodiment, as shown in FIG. 130 itself is made of an elastic FPC, and the connecting member (FPC) 110 in the first embodiment is omitted.
[0082]
That is, the connectors 132 and 134 are mounted on the connector board (FPC) 130, one connector 134 is used for connection of the harness 190, and the other connector 132 is used for connection with the connector 116 of the printed wiring board 80. It is to be noted that the through holes 136 are formed on both upper and lower sides of the connector 134, and the connector board 130 is fastened to the housing 90 by screws 128 as in the first embodiment.
[0083]
As described above, when the connector board 130 is formed of the FPC and is directly connected to the printed wiring board 80, the same effect as that of the first embodiment can be naturally obtained, and the number of connectors can be reduced as compared with the first embodiment. Therefore, it is possible to make the configuration resistant to noise and to reduce the number of parts, so that the assemblability can be improved. Note that it is preferable that a plate-like reinforcing member 138 wider than the connector 134 be attached to the base of the connector 134 attached to the connector board (FPC) 130 to reinforce that portion. It is needless to say that the same effect can be obtained even if the printed wiring board 80 is formed of an elastic FPC instead of the connector board 130, and furthermore, both boards are formed of FPCs.
[0084]
(Third embodiment)
Next, a third embodiment will be described. Also in the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The connector board 140 of the third embodiment is made of an FPC, as in the second embodiment. As shown in FIG. 7, a connector 144 for connecting the harness 190 and a connector 142 for connecting to the connector 116 of the printed wiring board 80 are mounted. The connector 142 side of the connector board (FPC) 140 that is connected to the printed wiring board 80 is bent twice in directions opposite to each other (to have a substantially “N” shape in plan view).
[0085]
It should be noted that through holes 146 are formed on both upper and lower sides of the connector 144 so that the connector board (FPC) 140 is fastened to the housing 90 by screws 128. It is preferable that a plate-like reinforcing member 148 wider than the connector 144 is attached to the base of the connector 144 to be attached to reinforce the portion, similarly to the first and second embodiments. .
[0086]
With such a configuration, the same effects as those of the first embodiment and the second embodiment can be obtained, and further, the displacement of the package member 68 and the semiconductor laser 16 can be further prevented. That is, for example, in a state where the connector board (FPC) 140 is fastened to the housing 90, the printed wiring board 80 is moved for position adjustment, and then fixed (to be held by the housing 90), Since a part of the (FPC) 140 (on the side of the connector 142) is formed by bending, it is possible to increase a movable allowable amount (degree of freedom) for adjusting the printed wiring board 80. The effect of the restraining force of 140) (the restraining force generated by the connection of the connector 116 and the connector 142) on the printed wiring board 80 (the effect of displacing the holding state) can be reduced as much as possible.
[0087]
Note that the connection member (FPC) 110 of the first embodiment is bent similarly, and as described in the second embodiment, not the connector board 140 but the printed wiring board 80 (or both) is made of an elastic material. It is needless to say that the same effect can be obtained by forming the printed wiring board 80 by bending the connector 116 side twice.
[0088]
In any case, by providing the connector boards 120, 130, and 140 separately from the printed wiring board 80, the printed wiring board 80 can be maintained at an ideal position at all times. The work of connecting the harness 190 can be performed without affecting the printed wiring board 80 when the apparatus 10 is attached to the housing 192 of the image forming apparatus 200 described later, so that the workability can be improved.
[0089]
<How to adjust the position of the printed wiring board>
Next, a method of adjusting the position of the printed wiring board 80 in the rotation direction about the optical axis will be described. In the embodiments shown in FIGS. 8 and 9, the same components as those shown in FIGS. 5 to 7 are denoted by the same reference numerals, and description thereof will be omitted. As shown in FIGS. 8 and 9, a hollow rotary shaft 156 is attached to the printed wiring board 80 at a position where the hollow rotary shaft 156 can rotate around the optical axis. While being inserted into the hole 154, it is held by the wave washer 158 in the housing 90 in a reduced pressure state.
[0090]
Further, a stepping motor 160 is attached to the housing 90 (the illustrated one is shown as if the stepping motor 160 is arranged on the printed wiring board 80), and a shaft portion 162 at the tip thereof is attached. It is in contact with the end face 80A of the printed wiring board 80. An urging member such as a leaf spring 164 having a substantially “U” shape in side view is in contact with the end surface 80B opposite to the stepping motor 160 with the printed wiring board 80 interposed therebetween. 80 is pressed against the stepping motor 160 by the urging force of the leaf spring 164.
[0091]
Therefore, when the stepping motor 160 is driven to rotate, the amount of protrusion of the shaft portion 162 at the tip is changed while the constraint in the rotational direction (the direction of the double arrow in the drawing) of the printed wiring board 80 is maintained, and the printed wiring board 80 In this configuration, the printed wiring board 80 is rotated around the optical axis, thereby adjusting the positional deviation of the printed wiring board 80 with respect to the optical axis in the rotation direction (appearing as a color deviation in the case of an image forming apparatus of color image quality).
[0092]
Here, the detection of the position shift and the position correction (position adjustment) will be described. In FIG. 10, one vertical column (eight pieces (1, a) to (8, a)) of the laser array 60 (see FIG. 3) is turned on, and the light beam is made incident on the synchronous sensor 48. The relationship between the inclination angle of the printed wiring board 80 and the output waveform of the synchronous sensor 48 in the case of FIG. From FIG. 10, it can be seen that the longer the time T during which the light beam is detected by the synchronous sensor 48, the greater the displacement of the laser array 60 in one vertical column, that is, the more the printed wiring board 80 is inclined. Therefore, by rotating the stepping motor 160 so that the time T becomes the shortest state, it is possible to correct the inclination shift (position shift in the rotation direction).
[0093]
[Configuration of Image Forming Apparatus]
Next, an image forming apparatus 200 having a tandem configuration to which the laser scanning device 10 according to the present invention is applied will be described. First, an outline of a color image forming apparatus 200 that forms a plurality of color images in one cycle will be briefly described, and then, a configuration of a main part will be described. In the following description, the same type of equipment provided for each color is distinguished by adding an alphabetic character representing the color after the code.
[0094]
As shown in FIGS. 11 and 12, the image forming apparatus 200 includes electrophotographic units 170Y for forming four color toner images of Y (yellow), M (magenta), C (cyan), and K (black). 170M, 170C, and 170K (hereinafter also referred to as 170Y to 170K; other reference numerals are also the same), and the transfer unit 176Y to 176K transfers the color toner image in which each toner image is accumulated to the sheet 188 supplied from the tray 186. And a fixing device 182 for fusing and fixing the color toner image transferred onto the paper 188. The electrophotographic units 170Y to 170K are provided around the photoconductors 12Y to 12K, respectively, around charging devices 172Y to 172K, laser scanning devices 10Y to 10K, developing devices 174Y to 174K, transfer devices 176Y to 176K, and cleaning devices 178Y to 178K. Are arranged and configured.
[0095]
In the image forming apparatus 200 having such a tandem configuration, a pattern for detecting a shift of a scanning line is formed on the transfer belt 184 so that a color shift does not occur in each color. Is measured for each color. Then, based on the detection result, control such as writing timing is performed to correct the color misregistration.
[0096]
That is, as shown in FIG. 3, FIG. 11, and FIG. 20, dot marks are positioned at the upper (1, a) in the vertical scanning direction M (the starting point) and the rear (the end point) in one vertical column (eight). The dot marks are formed below (8, a) at the front (starting point) and the rear (ending point) in the main scanning direction M at an interval that can be detected by the detection sensor 168. Then, the dot mark patterns (1, a) and (8, a) are repeated, and the interval (length) of the pattern in the main scanning direction M formed above and below is detected by the detection sensor 168. The difference between the detection result and the ideal interval is calculated. Further, the amount of color misregistration (the amount of misalignment in the rotation direction of the laser array 60) is calculated from the calculated value, and based on the result, the stepping motor 160 is rotationally driven by the corresponding number of steps, and Is rotated by a predetermined angle to correct the color misregistration.
[0097]
FIG. 13 shows the configuration of the drive / control circuit. The data measured by the detection sensor 168 is transmitted to the control unit 56, and the difference from the ideal value is calculated. Then, based on the result, a pulse signal is transmitted to the stepping motor drive circuit 166, and the stepping motor 160 is rotationally driven by the number of steps. Thereby, a light beam is irradiated to an ideal position. The dot mark may be visualized by irradiating and developing with the laser scanning device 10, but may be configured to be visualized by light in the laser scanning device 10.
[0098]
In addition, especially in the tandem-type image forming apparatus 200, there is a problem that the apparatus itself becomes large. In other words, the number of light sources increases as the speed of the image forming apparatus 200 increases, and accordingly, a harness 190 for transferring image data from a control unit (not shown) of the image forming apparatus 200 to the laser scanning apparatus 10. And the size of the connectors 124, 134 and 144 for connecting the harness 190 increases. Normally, when the connectors 124, 134, and 144 are to be housed in the housing 192 of the image forming apparatus 200, the size of the housing 192 naturally increases. That is, the image forming apparatus 200 becomes large.
[0099]
In order to reduce the size of the image forming apparatus 200, the following configuration is adopted. That is, as shown in FIGS. 14 to 16, a substantially rectangular opening for exposing the connectors 124, 134, 144 is provided at a predetermined position (between the square pipes 196, 198) of the housing 192 in which the laser scanning device 10 is disposed. A portion 194 is provided, and a harness 190 can be connected to the connectors 124, 134, 144 exposed from the opening 194 from the outside. With such a configuration, the size of the housing 192 can be reduced, and the connection of the harness 190 to the connectors 124, 134, 144 can be facilitated.
[0100]
In the tandem image forming apparatus 200, a retraction mechanism is provided on the transfer belt 184 in order to extend the life of the photoconductors 12Y to 12K, and the transfer belt 184 and the photoconductor 12 are brought into contact only when necessary. The configuration is increasing. That is, as shown in FIG. 17, retractable bars 202 to 210 that can be moved up and down are provided inside the transfer belt 184 and on the left and right of each of the photoconductors 12 </ b> Y to 12 </ b> K so that the contact surface of the transfer belt 184 with the photoconductor 12 is formed. 17, the laser scanning devices 10Y to 10K are arranged on a virtual circumference substantially along the transfer belt 184.
[0101]
Therefore, for example, when it is desired to form an image of only K color, the transfer devices 176Y, 176M, and 176C are moved downward (by retreating) by the retract bars (202 to 208), so that only the transfer device 176K is transferred. The belt 184 can be brought into contact with the photoconductor 12K.
[0102]
Further, in the image forming apparatus 200 having the retract mechanism, the same laser scanning device 10 is provided for each color, but each of the laser scanning devices 10Y to 10K has a predetermined virtual circumference when viewed from the front in FIG. Since the connector boards 120Y to 124K in the first embodiment, for example, the uppermost ends of the connectors 124M and 124C arranged at the highest positions among the connectors 124Y to 124K, The distance L from the lowermost end of the connector 124Y arranged at a lower position is longer (larger) than the height (width) W of the connectors 124Y to 124K themselves.
[0103]
Therefore, these laser scanning devices 10Y to 10K are arranged in a housing 192 shown in FIGS. 14 to 16 and connectors 124Y for four colors are provided through openings 194 formed between the square pipes 196 and 198 of the housing 192. To expose ~ 124K, the opening 194 must be provided on the imaginary circumference, so that the distance D between the square pipes 196 and 198 (see FIG. 15) needs to be widened to be equal to the distance L. Comes out. In this case, the height of the housing 192 is naturally increased.
[0104]
On the other hand, the square pipes 196 and 198 are provided at predetermined positions in order to increase the rigidity of the housing 192 and make the image forming apparatus 200 resistant to vibration and impact. A square pipe 196 is provided at the uppermost edge of the housing 192, and a square pipe 198 is provided near the lower portion of the laser scanning device 10 (between the laser scanning device 10 and the photoconductor 12). In other words, if the square pipes 196 and 198 are not provided at the above-described positions, and furthermore, if one of the square pipes 196 and 198 is not provided, the rigidity of the housing 192 naturally increases. Therefore, the image forming apparatus 200 is less susceptible to vibration and impact. For this reason, the arrangement positions of the square pipes 196 and 198 cannot be changed or removed to a position completely different from the above position.
[0105]
Therefore, in order to arrange the connectors 124Y to 124K (harness 190) between the square pipes 196 and 198 without increasing the height of the housing 192, the mounting position of the connector 124 to the housing 90 is externally adjusted. It is made possible (the position is moved and held from the outside). That is, as shown in FIGS. 18 and 19, for example, a bracket 150 of a predetermined size is integrally connected to the upper right and lower left (or upper left and lower right) of the connector board 120, and A vertically elongated long hole 152 is formed, and a screw 128 is inserted into the long hole 152 to attach the connector board 120 to the housing 90.
[0106]
With such a configuration, the connector board 120 can be moved up and down along the long hole 152. For example, in the case of the laser scanning devices 10Y to 10K shown in FIG. 17, the positions of the connector boards 120M and 120C are changed. The value of the distance L can be minimized by moving the connector boards 120Y and 120K upward and adjusting them by moving them downward. As a result, the distance D between the square pipes 196 and 198 can be made closer to the width W of the connectors 124Y to 124K, so that, for example, the square pipe 196 can be provided as low as possible (a position close to the square pipe 198). , The height of the housing 192 can be reduced. That is, since the height of the image forming apparatus 200 can be reduced, the size of the image forming apparatus 200 can be reduced. At this time, since the opening 194 is formed in the housing 192, the position adjustment using the screw 128 can be easily performed from outside the housing 192.
[0107]
In addition, if the laser scanning device 10 arranged so as to be compatible with the retracting mechanism (on the virtual circumference substantially along the transfer belt 184) has a different shape for each color, that is, the positions of the connectors 124Y to 124K are changed. If different laser scanning devices 10Y to 10K are prepared for each color, the height of the housing 192 can be reduced, but this makes the management of the laser scanning devices 10Y to 10K having different shapes complicated. Failure occurs. Therefore, it is preferable that the connector board 120 (the same applies to the connector boards 130 and 140) has the above-described configuration in which the position can be adjusted. In this embodiment, the configuration of the VCSEL has been described. However, it goes without saying that the same effect can be obtained with a single LD.
[0108]
【The invention's effect】
In any case, according to the present invention, even if the harness is attached to or detached from the optical scanning device, the light emitting element attached to the substrate does not change in tilt, so that a high quality image can be provided. In addition, since the harness can be connected from the outside of the image forming apparatus, the harness can be easily attached to and detached from the optical scanning device, and the size of the image forming apparatus can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a laser scanning device.
FIG. 2 is a block diagram showing a drive / control circuit in the laser scanning device.
FIG. 3 is a schematic plan view showing a configuration of a surface emitting semiconductor laser (VCSEL).
FIG. 4 is a schematic cross-sectional view illustrating a configuration of a surface emitting semiconductor laser (VCSEL).
FIG. 5 is a schematic exploded perspective view showing a first embodiment of a connector board mounting structure.
FIG. 6 is a schematic exploded perspective view showing a second embodiment of the connector substrate mounting structure.
FIG. 7 is a schematic exploded perspective view showing a third embodiment of the connector substrate mounting structure.
FIG. 8 is a schematic exploded perspective view showing a mounting structure of a printed wiring board.
FIG. 9 is a schematic front view showing a mounting structure of a printed wiring board.
FIG. 10 is a diagram showing the relationship between the waveform of the SOS detector and the dot arrangement.
FIG. 11 is a schematic perspective view showing a main part of the image forming apparatus.
FIG. 12 is a schematic configuration diagram illustrating a main part of the image forming apparatus.
FIG. 13 is a block diagram showing a drive / control circuit in the laser scanning device.
FIG. 14 is a schematic front view showing a housing of the image forming apparatus.
FIG. 15 is a schematic perspective view of a housing to which a laser scanning device is attached.
FIG. 16 is a schematic side view of a housing to which a laser scanning device is attached.
FIG. 17 is a schematic configuration diagram illustrating a main part of an image forming apparatus having a retract mechanism.
FIG. 18 is a schematic perspective view of a laser scanning device.
FIG. 19 is a schematic front view of a laser scanning device.
FIG. 20 is a diagram showing the relationship between a surface emitting semiconductor laser (VCSEL) and image quality.
FIG. 21 is a schematic perspective view of a conventional laser scanning device.
FIG. 22 is a schematic sectional view of a conventional laser scanning device.
FIG. 23 is an exploded perspective view of a conventional semiconductor laser mounting structure.
[Explanation of symbols]
10 Laser scanning device (optical scanning device)
16 Semiconductor laser
58 Laser Array Drive Circuit
60 laser array (light emitting element)
80 Printed Wiring Board
90 case
100 elastic connecting member
110 connecting member
120 Connector board
130 Connector board
140 Connector board
160 stepper motor
190 harness
192 housing
194 opening
200 Image forming apparatus

Claims (9)

A first substrate on which a light emitting element and a driving circuit thereof are mounted and which is attached to a housing fixed to the image forming apparatus main body;
A second board mounted with a connector for connecting a harness from the image forming apparatus main body, separated from the first board, and attached to the housing;
An elastically deformable connection member for electrically connecting the terminal of the first substrate and the terminal of the second substrate;
An optical scanning device comprising: A first substrate on which a light emitting element and a driving circuit thereof are mounted and which is attached to a housing fixed to the image forming apparatus main body;
An elastically deformable second substrate mounted with a connector for connecting a harness from the image forming apparatus main body and separated from the first substrate and attached to the housing;
A fixed terminal provided on the second substrate and electrically connected to a terminal of the first substrate;
An optical scanning device comprising: The optical scanning device according to claim 1, wherein the connection member is bent and formed twice or more. The optical scanning device according to claim 2, wherein the second substrate is bent and formed twice or more. The optical scanning device according to claim 1, wherein the first substrate is attached to the housing so as to be position-adjustable. The optical scanning device according to claim 1, wherein the light emitting elements are configured in an array. A sensor for detecting an inclination angle of the light emitting elements configured in the array with respect to the sub-scanning direction,
Rotation adjustment means for adjusting the rotation of the first substrate based on a detection result by the sensor;
The optical scanning device according to claim 6, further comprising: A housing in which the optical scanning device according to claim 1 can be arranged,
An opening formed in the housing to expose a connector mounted on the second board;
An image forming apparatus comprising: The image forming apparatus according to claim 8, wherein the second substrate is attached to a housing of the optical scanning device such that the position of the second substrate can be adjusted.

Images