JP4518064B2 - Optical member holding means and optical scanning device provided with the same - Google Patents

Description

The present invention relates to the first optical member and the optical member holding device capable of adjusting the position of the second optical member, and the optical scanning equipment having the same.

  In a conventional electrophotographic image forming apparatus such as a laser printer or a copying machine, a photosensitive member is charged in an image forming unit, and an electrostatic latent image is formed on the photosensitive member by exposure with a laser beam emitted from an optical scanning device. An image is formed by forming an image, transferring the image made visible with a developer such as toner, onto a recording medium such as paper, and fixing the image by heating with a fixing device or the like. In the optical scanning device, laser light emitted from a point light source such as a laser diode (hereinafter referred to as “LD”) is collimated into parallel light by a collimating lens, and the spread of the light flux is regulated through a slit, and only in one direction. Are focused by a cylindrical lens that refracts the light and imaged on a rotating polygon mirror. The light beam reflected by the polygon mirror is scanned in one direction and emitted from the optical scanning device toward the photosensitive member via various lenses and mirrors. In such an optical scanning apparatus, unless the alignment of the starting point of the light beam, that is, the LD and the collimating lens, is performed with high accuracy, the degree of defocus in the optical path thereafter increases.

For example, in Patent Document 1, a lens holder (lens cell) that supports a collimating lens and an LD holder that supports an LD are fixed to a support member (support portion). Is moved in the optical axis direction to adjust the focus in that direction, and the LD holder is shifted in parallel with the surface facing the support member to move in the plane direction perpendicular to the optical axis direction of the laser beam. The focus is adjusted. During the position adjustment of the lens holder, the lens holder is temporarily fixed to the support member with a pressing spring, and finally fixed with an adhesive. The LD holder is fixed by tightening a screw after adjusting the position.
JP 2000-284203 A

  However, the LD holder and the support member are in surface contact, and the contact surfaces are fixed in a twisted state by tightening the screws, and distortion in the rotational direction of the screws occurs between the contact surfaces. Due to this distortion, there is a problem that a deviation occurs between the LD and the collimating lens, and the formed image is disturbed.

The present invention has been made to solve the above-described problems, and includes an optical member holding unit capable of aligning the first optical member and the second optical member in a non-contact state, and the same. and an object thereof is to provide an optical scanning equipment.

  In order to achieve the above object, the optical member holding means according to the first aspect of the present invention includes a first support plate that supports a lens holder that holds a lens, and a light source that faces the first support plate. In order to fix the first support plate with an adhesive while placing the first support plate between the second support plate and the first support plate, the second support plate is disposed vertically and parallel to each other. A first fixing plate and a second fixing plate, an adjustment plate arranged vertically connected to the second fixing plate, and a first connection between the first fixing plate and the second support plate The second support plate is moved with respect to the first support plate, with the connection portion serving as a fulcrum and the portion of the second support plate facing the adjustment plate as a force point. Adjustment means for adjusting the position of the lens and the light source is provided.

Further, the optical member holding device of the invention according to claim 2, in addition to the configuration of the invention according to claim 1, wherein the lens holder has a linear expansion coefficient and equal correct linear expansion coefficient of the first support plate It is comprised from the member, It is characterized by the above-mentioned.

  In addition to the configuration of the invention according to claim 1 or 2, the optical member holding means according to a third aspect of the invention includes the first support plate of the first support plate from the lens center of the lens held by the lens holder. The distance to the end portion on the first fixed plate side is equal to the distance to the end portion on the second fixed plate side of the first support plate.

  According to a fourth aspect of the present invention, there is provided an optical member holding means for connecting the first fixing plate and the second fixing plate in addition to the configuration of the invention according to any one of the first to third aspects. 3, and the third fixing plate is provided with a slit member that stops the light beam emitted from the light source and passing through the lens.

  In addition to the configuration of the invention according to any one of claims 1 to 3, the optical member holding means according to the invention according to claim 5 includes a light beam that is emitted from the light source and passes through the lens. A slit member for performing a diaphragm is provided.

According to a sixth aspect of the present invention, there is provided an optical scanning device according to any one of the first to third and fifth aspects, wherein the optical member holding means and the reflection direction of the light beam emitted from the optical member holding means are changed. A rotating polygon mirror that performs scanning, a driving unit that rotates the rotating polygon mirror, an imaging unit that forms an image of a light beam scanned by the rotating polygon mirror on an imaging medium, and the optical member holding unit; The rotating polygon mirror, the driving means, and a frame for accommodating the imaging means are provided.

According to a seventh aspect of the present invention, there is provided an optical scanning device according to the fourth aspect of the present invention, and a rotary polygon mirror that performs scanning by changing a reflection direction of a light beam emitted from the optical member holding unit. Driving means for rotating the rotary polygon mirror, image forming means for forming an image of a light beam scanned by the rotary polygon mirror on an image forming medium, the optical member holding means, the rotary polygon mirror, A driving unit and a frame for accommodating the imaging unit are provided.
According to an eighth aspect of the invention, in addition to the configuration of the seventh aspect of the invention, the third fixing plate is fixed to the frame.

An optical scanning device according to a ninth aspect of the invention is characterized in that, in addition to the configuration of the invention according to any one of the sixth to eighth aspects , the frame is formed of a resin mixed with a reinforcing agent. To do.

  In the optical member holding means according to the first aspect of the invention, the first support plate that supports the first optical member is fixed to the first fixing plate and the second fixing plate, and supports the second optical member. The second support plate is connected to the first fixed plate via the connecting portion, and the first support plate and the second support plate are not in direct contact with each other. When adjusting the position with the second optical member, it is possible to maintain the adjusted position by being released from the distortion between the contact parts that occurs when there is a contact part. Further, since the lens is supported by the lens holder and then fixed to the first support plate, the lens can be easily handled and the position can be easily adjusted when the lens is fixed.

  Further, in the optical member holding means of the invention according to claim 2, in addition to the effect of the invention according to claim 1, the linear expansion coefficient of the lens holder and the linear expansion coefficient of the first support plate are equal, so that the ambient temperature Even if it changes, the distortion | strain between both does not generate | occur | produce and the position of a lens can be maintained stably.

  Further, in the optical member holding means of the invention according to claim 3, in addition to the effect of the invention according to claim 1 or 2, by designing in advance so that the lens center comes to the center position of the first support plate, Even when the first support plate fixed between the first fixed plate and the second fixed plate is thermally expanded, the lens center is the center with respect to the direction of the first fixed plate and the second fixed plate. Since the respective thermal expansion amounts are the same, the lens position can be stably maintained.

  Further, in the optical member holding means of the invention according to claim 4, in addition to the effect of the invention according to any one of claims 1 to 3, the spread and limitation of the luminous flux emitted from the optical member holding means by the slit member are made uniform. Can be achieved.

  Further, in the optical member holding means of the invention according to claim 5, in addition to the effect of the invention according to any one of claims 1 to 3, the spread and limitation of the luminous flux emitted from the optical member holding means by the slit member are made uniform. Can be achieved. Further, by providing directly to the lens holder, it is possible to reduce the portion that becomes a tolerance at the time of manufacturing, so that it is possible to refine the product.

According to a sixth aspect of the present invention, in the optical scanning device of the invention, the optical scanning device includes the optical member holding means according to any one of the first to third and fifth aspects. Since it is easy to adjust the emitted light beam, the production cost can be reduced.

According to a seventh aspect of the present invention, the optical scanning device includes the optical member holding means according to the fourth aspect, and adjusts the light beam emitted toward the rotary polygon mirror during production. Since it is easy, the production cost can be reduced.
Further, in the optical scanning device of the invention according to claim 8, in addition to the effect of the invention according to claim 7, since the third fixing plate is fixed to the inner wall surface of the frame, the first support is provided if the frame is fixed. The plate can be fixed, the luminous flux emitted from the optical member holding means can be adjusted efficiently, and the production cost can be reduced.

Further, in the optical scanning device according to the ninth aspect of the invention, in addition to the effect of the invention according to any of the sixth to eighth aspects , the frame is made of resin mixed with a reinforcing agent, thereby increasing the rigidity of the frame. The production cost can be reduced as it is.

Hereinafter, an embodiment of an optical scanning device embodying the present invention will be described with reference to the drawings. First, the overall configuration of a laser printer 1 as an example of an image forming apparatus including an optical scanning device according to the present invention will be described with reference to FIG. FIG. 1 is a central sectional view of the laser printer 1.

  As shown in FIG. 1, the laser printer 1 includes a feeder unit 4 for feeding a sheet 3 as a recording medium in a main body case 2 in a cross-sectional view, and a printer for printing on a fed sheet 3. A scanner unit 200, a process cartridge 17, and a fixing device 18 constituting an image forming unit are provided. In the laser printer 1, the right hand direction in the figure is the front surface.

  The paper discharge tray 46 is formed with a recess at a position from the upper center to the front side of the main body case 2 so that the printed sheets 3 can be stacked and held so that the inclination becomes smaller toward the front side of the main body case 2. In addition, an upper portion of the front surface of the main body case 2 has a partially open space for inserting the process cartridge 17. The process cartridge 17 is a cover on the front surface side (right hand side in the figure) of the main body case 2. It is attached / detached in a state where it is widely opened by turning 54 downward.

  In the rear part (left hand side in the figure) in the main body case 2, the paper 3 discharged from the fixing device 18 provided on the lower rear end side in the main body case 2 is guided to a paper discharge tray 46 provided in the upper part. As described above, a paper discharge path 44 is provided so as to draw a semi-arc in the vertical direction along the back surface of the main body case 2, and a paper discharge roller 45 for conveying the paper 3 is provided in the paper discharge path 44. .

  The feeder unit 4 is provided in the paper feed cassette 6, which is mounted on the bottom of the main body case 2, a paper feed cassette 6 that is detachably mounted in the front-rear direction from the front surface of the laser printer 1. A sheet pressing plate 7 that holds the sheet 3 in a stacked manner and presses the sheet 3 against the sheet feeding roller 8, and is provided above one end of the sheet feeding cassette 6 and is pressed toward the sheet feeding roller 8 for feeding. A separation pad 9 that separates the sheets 3 one by one in cooperation with the sheet feeding roller 8 at the time of sheeting, and is provided on the downstream side of the sheet feeding roller 8 in the sheet 3 conveying direction, and conveys the sheet 3. A conveyance roller 11, a paper dust removing roller 10 that contacts the conveyance roller 11 via the sheet 3 to remove the paper dust and conveys the sheet 3 in cooperation with the conveyance roller 11, and the conveyance roller 11 It is provided on the downstream side in the transport direction of the paper 3 and is used for printing. And a registration roller 12 for adjusting the timing of delivery of 3.

  The sheet pressing plate 7 can stack the sheets 3 in a stacked manner, and a support shaft 7 a provided at the end far from the sheet feeding roller 8 is supported on the bottom surface of the sheet feeding cassette 6. With the support shaft 7a as the center of rotation, the near end is movable in the vertical direction, and is biased toward the paper feed roller 8 by the spring 7b from the back side. Therefore, as the amount of stacked sheets 3 increases, the sheet pressing plate 7 is swung downward against the urging force of the spring 7b with the support shaft 7a as a fulcrum. The paper feed roller 8 and the separation pad 9 are disposed so as to face each other, and the separation pad 9 is pressed toward the paper feed roller 8 by a spring 13 disposed on the back side of the separation pad 9.

  Note that the paper dust generated by the friction between the paper 3 and the separation pad 9 during paper feeding is a paper dust removing roller 14 disposed so as to cooperate with the paper feeding roller 8 downstream of the separation pad 9. It is electrostatically attracted to the surface and is entangled and removed by the sponge 14a. The paper dust that cannot be completely removed by the paper dust removing roller 14 is removed by the paper dust removing roller 10 so as not to enter the image forming unit.

  A duplex printing unit 26 is disposed above the paper feed cassette 6. The duplex printing unit 26 is provided with reverse conveying rollers 50a, 50b, and 50c in a substantially horizontal direction, and reverse conveying paths 47a and 47b are connected to both ends thereof. The reverse conveyance path 47a is provided on the inner surface side of the back cover 48 and is branched from the paper discharge path 44 when the paper 3 is conveyed in the reverse direction at the end position of the paper discharge path 44 in the paper 3 conveyance direction. The paper discharge roller 45 and the reverse conveyance roller 50a are connected via the reverse conveyance path 47a so as to be guided to the printing unit 26. The reverse conveyance path 47b connects the reverse conveyance roller 50c and the registration roller 12 so as to guide the sheet 3 to the image forming unit.

  When double-sided printing is performed, first, the paper 3 on which image formation has been performed on one side is conveyed, and a part of the paper 3 is temporarily discharged to the paper discharge tray 46. When the rear end of the paper 3 is sandwiched between the paper discharge rollers 45, the paper discharge rollers 45 stop rotating in the normal direction and perform the reverse rotation. Then, the rear end of the sheet 3 comes into contact with the arc surface of the paper discharge path 44 and is guided to the reverse conveyance path 47a along the arc surface without returning to the fixing unit 18 direction. The sheet 3 is transported from the reverse transport path 47a to the reverse transport rollers 50a, 50b, and 50c, sent to the reverse transport path 47b, and guided to the registration roller 12 along the reverse transport path 47b. By following such a conveyance path, when the sheet 3 is conveyed from the paper discharge roller 45 to the registration roller 12, the sheet 3 is conveyed in the reverse direction, and the surface on which printing has already been performed faces downward. Inverted and sent to the image forming unit. In the image forming unit, an image is also formed on the other side of the sheet 3.

  Further, a low voltage power supply substrate 90, a high voltage power supply substrate 95, and an engine substrate 85 are provided at a position between the double-sided printing unit 26 and the image forming unit. In order to isolate it from other devices, a chute 80 is provided between each substrate and the image forming unit, and a guide plate 81 provided on the chute 80 constitutes a part of the conveyance path of the sheet 3. . In addition, the chute 80 is installed and supported between left and right main body frames (not shown) that are supported by sandwiching each component device of the laser printer 1.

  The low-voltage power supply board 90 is a circuit board for dropping, for example, a single-phase voltage of 100 V supplied from the outside of the laser printer 1 to a voltage of, for example, 24 V in order to supply each part inside the laser printer 1. . The high-voltage power supply board 95 is a circuit board that generates a high-voltage bias applied to each part of the process cartridge 17 described later. The engine board 85 is a DC motor (not shown), which is a drive source of components that involve mechanical operations such as the rollers of the laser printer 1, and a solenoid (not shown) for switching the operation direction of the drive system. It is a circuit board for driving etc.

  Next, the process cartridge 17 of the image forming unit includes a drum cartridge 23 and a developing cartridge 24 that can be attached to and detached from the drum cartridge 23. The drum cartridge 23 includes a photosensitive drum 27, a scorotron charger 29, a transfer roller 30, and the like. The developing cartridge 24 includes a developing roller 31, a supply roller 33, a toner hopper 34, and the like.

  The photosensitive drum 27 of the drum cartridge 23 is disposed so as to be rotatable in the direction of the arrow (clockwise in the figure) while being in contact with the developing roller 31. The photoreceptor drum 27 is a positively charged organic photoreceptor in which a positively charged organic photoreceptor is coated on a conductive substrate, and a charge generating material is dispersed in a charge transport layer. When the photosensitive drum 27 is irradiated with a laser beam or the like, charges are generated by the charge generation material by light absorption, and the charges are transported to the surface of the photosensitive drum 27 and the conductive base material by the charge transport layer. Further, by eliminating the surface potential charged in the scorotron charger 29, a potential difference can be provided between the potential of the irradiated portion and the potential of the unreceived portion. An electrostatic latent image is formed on the photosensitive drum 27 by performing exposure scanning with laser light based on the print data.

  The scorotron charger 29 as charging means is disposed above the photosensitive drum 27 at a predetermined interval so as not to contact the photosensitive drum 27. The scorotron charger 29 is a scorotron charger that generates corona discharge from a discharge wire such as tungsten. The scorotron charger 29 is turned on by a charging bias circuit (not shown) of the high-voltage power supply board 95 to It is configured to uniformly charge the surface to positive polarity.

  When the developing cartridge 24 is mounted on the drum cartridge 23, the developing roller 31 is disposed downstream from the position of the scorotron charger 29 in the rotation direction of the photosensitive drum 27 (clockwise in the figure). It is arranged to be rotatable in the direction of the arrow (counterclockwise in the figure). The developing roller 31 has a metal roller shaft covered with a roller made of a conductive rubber material, and a developing bias is applied from a developing bias circuit portion (not shown) of the high-voltage power supply substrate 95.

  Next, the supply roller 33 is rotatably disposed at a position on the side of the developing roller 31 and on the opposite side of the photosensitive drum 27 with the developing roller 31 interposed therebetween, and compresses the developing roller 31. The contact is made in such a state. The supply roller 33 has a metal roller shaft covered with a roller made of a conductive foam material, and frictionally charges the toner supplied to the developing roller 31. Therefore, the supply roller 33 is disposed so as to be rotatable in the arrow direction (counterclockwise in the figure) which is the same direction as the developing roller 31.

  Further, the toner hopper 34 is provided at a side position of the supply roller 33, and the developer supplied to the developing roller 31 via the supply roller 33 is filled therein. In the present embodiment, a positively chargeable non-magnetic one-component toner is used as a developer, and this toner is a polymerizable monomer, for example, a styrene monomer such as styrene, acrylic acid, alkyl ( It is a polymerized toner obtained by copolymerizing acrylic monomers such as C1-C4) acrylate and alkyl (C1-C4) methacrylate by a known polymerization method such as suspension polymerization. In such a polymerized toner, a colorant such as carbon black, wax, and the like are blended, and an external additive such as silica is added in order to improve fluidity. The particle diameter is about 6 to 10 μm.

  The agitator 36 is a rough mesh-like plate body having a substantially U-shape in a cross-sectional view and extending in the axial direction (the front and back direction in the figure), and is provided with a rotating shaft 35 at one end, Film members 36a configured to rub against the inner wall of the toner hopper 34 are provided at two locations, the middle part of the letter-shaped shape. Then, the toner stored in the toner hopper 34 is agitated by rotating the agitator 36 with the shaft 35 supported at the center positions of both ends in the longitudinal direction of the toner hopper 34 in the arrow direction (clockwise in the figure).

  A transfer roller 30 is disposed downstream of the developing roller 31 in the rotational direction of the photosensitive drum 27 and below the photosensitive drum 27, and is rotatable in the direction of the arrow (counterclockwise in the figure). It is supported. The transfer roller 30 has a metal roller shaft covered with a roller made of an ion conductive rubber material. During transfer, a transfer bias is applied from a transfer bias circuit portion (not shown) of the high-voltage power supply board 95. It is comprised so that. The transfer bias is a bias applied to the transfer roller 30 so that a potential difference is generated in a direction in which the toner electrostatically adhered onto the surface of the photosensitive drum 27 is electrically attracted onto the surface of the transfer roller 30.

  In this laser printer 1, a so-called cleaner-less developing system in which the toner remaining on the surface of the photosensitive drum 27 is collected by the developing roller 31 after the toner is transferred from the photosensitive drum 27 to the paper 3 by the transfer roller 30. Is adopted.

  Next, the fixing device 18 of the image forming unit is disposed on the downstream side of the process cartridge 17, and includes a fixing roller 41, a pressure roller 42 that presses the fixing roller 41, and the fixing roller 41 and the pressure roller. A pair of transport rollers 43 provided on the downstream side of 42 are provided. The fixing roller 41 is a roller in which a hollow aluminum shaft is coated with a fluororesin and baked, and includes a halogen lamp 41a for heating inside a cylindrical roller. The pressure roller 42 is a roller in which a fluororesin tube is coated on a shaft made of low hardness silicon rubber. The shaft is urged upward by a spring (not shown), so that the fixing roller 41 is pressed. It is pressed. In the fixing device 18, the toner transferred onto the paper 3 in the process cartridge 17 is pressed and heated and fixed while the paper 3 passes between the fixing roller 41 and the pressure roller 42. The paper is transported to the paper discharge path 44 by the transport roller 43.

  Next, the scanner unit 200 will be described with reference to FIGS. FIG. 2 is a perspective view of the scanner unit 200 as viewed from above with the upper lid member 201 removed. FIG. 3 is a perspective view of the scanner unit 200 viewed from an angle different from that of FIG. 2 with the upper cover member 201 and the tray 203 removed.

  As shown in FIG. 1, the housing of the scanner unit 200 includes a resin scanner frame 202 mixed with a reinforcing agent such as glass fiber, an iron upper lid member 201 that covers and covers the upper portion, and a lower portion of the scanner frame 202. , And a tray 203 made of a steel plate that is fixed by screws between the left and right main body frames (not shown) of the laser printer 1. The scanner frame 202 is a “frame” in the present invention.

  As shown in FIG. 2, the tray 203 is formed in a shallow box shape in which four sides of a substantially rectangular plate material are bent in the same direction. Two screwing holes are formed in each of the bent portions at both ends in the longitudinal direction so as to be bridged and fixed between the main body frames (not shown). An opening 203a (see FIG. 1) that is elongated in the longitudinal direction is provided at a substantially central position of the tray 203. The scanner frame 202 has an outer wall 202a standing in a direction substantially perpendicular to the bottom surface of the tray 203, and an inner side surrounded by the outer wall 202a. Thus, a partition 202b that divides the scanner frame 202 into two upper and lower layers near the middle of the outer wall 202a.

An upper layer above the partition wall 202b of the scanner frame 202 is disposed at one end in the longitudinal direction of the scanner frame 202 and emits laser light to be described later, and laser light emitted from the laser unit 300 in the vertical direction. A cylindrical lens 210 that is refracted to form an image on the polygon mirror 220, and is disposed at one end in the short-side direction. Six mirror surfaces are provided around a hexagonal rotating body, and an image is formed on the mirror surface. A polygon mirror 220 that scans the laser beam in the horizontal direction, an fθ lens 230 that converts the laser beam reflected by the polygon mirror 220 and scanned at a constant angular velocity into a constant velocity scan, and the other end in the short direction, fθ A mirror 240 that reflects and relays the laser light that has passed through the lens 230 to the lower layer side of the scanner frame 202 is provided. That.

  As shown in FIG. 1, on the lower layer side of the scanner frame 202, the laser beam relayed to the mirror 240 is folded back in the internal direction of the scanner frame 202, and the laser beam is corrected for correction of surface tilt in the polygon mirror 220. A cylindrical lens 260 that refracts the light beam in the vertical direction, and laser light that has passed through the cylindrical lens 260 are emitted from the scanner unit 200 through the opening 203a of the tray 203 and imaged on the surface of the photosensitive drum 27. A mirror 270 that reflects the light is disposed. The fθ lens 230, the mirrors 240, 250, and 270, and the cylindrical lens 260 are “imaging means” in the present invention.

  As shown in FIGS. 2 and 3, the laser emitted from the motor 221 that drives the polygon mirror 220 to rotate and the laser unit 300 along the outer wall surface on the short side of the scanner frame 202 on which the laser unit 300 is arranged. A circuit board 204 is provided for adjusting the light output and the like. An adjustment hole 205 is formed in the circuit board 204, and a through-hole 202d is also formed in the outer wall of the scanner frame 202 corresponding to the adjustment hole 205, so that the optical axis of the laser unit 300 described later is adjusted. Sometimes a driver can be inserted. Further, an inspection hole 202c for optical axis inspection is provided on the wall surface of the scanner frame 202 that is an extension of the optical axis (indicated by a two-dot chain line in the figure) of the laser light emitted from the LD 350 emitted to the polygon mirror 220. Is provided. The motor 221 is the “driving means” in the present invention.

  By the way, the polygon mirror 220 is rotationally driven by the motor 221, which causes an air flow in the scanner unit 200. Then, dust or toner powder may be sucked into the scanner unit 200, and if such dust adheres to the lens or mirror surface and decreases the transmittance or reflectance of the laser beam, The light intensity of the laser light that exposes the body drum 27 is lowered, resulting in insufficient exposure, and adverse effects such as a decrease in the amount of toner attached to the paper 3 and a thin print result. In order to prevent this, in the scanner unit 200, an elastic member such as urethane foam is sandwiched between the outer wall 202a of the scanner frame 202, the upper lid member 201, and the tray 203, and the scanner unit 200 is almost sealed. It has become a state. This urethane foam also functions as a cushioning material for making it difficult for vibration generated with the rotation of the motor 221 to be transmitted to the tray 203.

  Next, the configuration of the laser unit 300 will be described with reference to FIGS. FIG. 4 is a development view of the laser unit 300. FIG. 5 is a perspective view showing the laser unit 300. FIG. 6 is a perspective view showing the laser unit 300 viewed from an angle different from that in FIG. In the following drawings, the optical axis direction of the laser light in the laser unit 300 is the Z-axis direction, and the vertical direction and the left-right direction when the laser unit 300 is attached to the scanner frame 202 are the Y-axis direction and the X-axis direction, respectively.

  As shown in FIG. 4, the laser unit 300 is formed by bending a single aluminum plate, and includes an LD support portion 310 that supports the LD 350 and a substantially rectangular aluminum plate. And a slit plate 330 provided with elongated slits in the horizontal direction. In addition, it is desirable that the surface of the aluminum plate is subjected to a lustrous process for increasing the reflectance of light from the viewpoint of fixing a lens support 320 described later.

The LD support unit 310 includes a fixing unit 311 that fixes the lens support unit 320 and the slit plate 330, a holding unit 312 that fixes the LD 350, and an adjustment unit 313 that adjusts the position of the LD 350 in the optical axis direction. Is done. The fixing portion 311 has a substantially rectangular bottom plate 311a and a side plate extending from one end side (−X direction side) in the short side direction to have a width substantially the same as the bottom plate 311a and slightly shorter than the length in the short side direction of the bottom plate 311a. 311b and an edge on the other end side (+ X direction side) of the bottom plate 311a, extending from a substantially central portion in the longitudinal direction of the bottom plate 311a to an end portion on the −Z direction side by substantially the same length as the side plate 311b. It is comprised from the made side plate 311c. As shown in FIGS. 5 and 6, the side plates 311b and 311c are bent in the same direction (+ Y direction) substantially orthogonal to the bottom plate 311a. At this time, the surface directions of the side plates 311b and 311c are substantially the same. It arrange | positions facing so that it may become parallel. Further, a positioning projection 311d for positioning the slit plate 330 and a screw hole 311e for fastening the slit plate 330 with screws are provided at the end of the bottom plate 311a on the + Z direction side .

  As shown in FIG. 4, the holding portion 312 extends in a direction longer than the edge of the side plate 311 b on the −Z direction side than the short side direction of the bottom plate 311 a. A connection portion 314 between the side plate 311b and the holding portion 312 is perforated at a substantially central position, and the connection portion 314 is divided into two in the extending width direction to reduce the connection width. This is to reduce the rigidity of the connection portion 314 and make it easier to bend when the connection portion 314 is bent, which will be described later. As shown in FIGS. 5 and 6, when the side plate 311b is bent with respect to the bottom plate 311a, the holding portion 312 is connected to the side plate 311b so that the extended end portion 312a faces the side plate 311c. It is bent at a portion 314. That is, the surface of the holding portion 312 is substantially orthogonal to each surface of the plate surface of the fixed portion 311, but the bending position is about the thickness of the aluminum plate from the edge of the side plate 311 b, and is closer to the holding portion 312. The holding part 312 does not contact the bottom plate 311a. A support hole 312b for press-fitting and supporting the LD 350 is formed in a portion of the bottom portion 311a which is substantially centered in the vertical direction (Y-axis direction) of the bent holding portion 312 and corresponding to the center of the bottom plate 311a. Two screw holes 312c for screwing the LD substrate 206 (see FIG. 2) for fixing the terminals of the press-fitted LD 350 are provided around the periphery. The extended end portion 312a is provided with an oval adjustment hole 312d having a long axis in the extending direction of the holding portion 312. The LD substrate 206 is connected to the circuit substrate 204 (see FIG. 2) with a flat cable (not shown). The holding portion 312 is the “second support plate” in the present invention. The connection portion 314 is a “connection portion” in the present invention, and the LD 350 is a “light source” in the present invention.

  As shown in FIG. 4, the adjusting portion 313 includes a side plate 313 a extended from the edge of the side plate 311 c on the −Z direction side by the same length of the side plate 311 c and a bottom plate 311 a of the side plate 313 a. It is comprised from the edge (edge side of the -X direction) and the baseplate 313b extended by the same magnitude | size as the sideplate 313a. As shown in FIGS. 5 and 6, when the side plate 311b is bent with respect to the bottom plate 311a, the side plate 313a is bent from the side plate 311c in the opposite direction (+ X direction) to the bottom plate 311a. Then, the surface of the side plate 313a is orthogonal to the surfaces of the bottom plate 311a and the side plate 311c. The bottom plate 313b is bent to the surface of the side plate 311c and becomes parallel to the bottom plate 311a. The bottom plate 313b has a screw hole d for fixing to the scanner frame 202. In this state, the side plate 313a is opposed to the extended end 312a of the holding portion 312 and a circular screw hole 313c is formed at a position corresponding to the approximate center of the adjustment hole 312d. The extended end 312a and the side plate 313a are opposed so that the distance between the surfaces does not open beyond the length of the screw 370, and the holding portion 312 is bent so as not to come into contact with each other. Is called. And the position adjustment mentioned later is performed by the tightening degree when the screw 370 is inserted from the adjustment hole 312d side and fastened by the screw hole 313c. The adjusting portion 313, the extended end portion 312a of the holding portion 312 and the screw 370 are the “adjusting means” in the present invention.

  As shown in FIG. 4, the lens support part 320 is a substantially rectangular plate, and the width B in the short side direction is the inner dimension width A after the bottom plate 311a is bent in the short direction, that is, the side plate arranged in parallel. It is designed to be narrower by 100 μm or more than the length between 311b and 311c (see FIG. 5). A support hole 320a for supporting the collimator lens 360 is formed in the center. The support hole 320a is formed so that the lens center of the collimator lens 360 is located at the center position of the lens support portion 320 in the X-axis direction. In addition, a corner portion on one end side in the longitudinal direction is omitted, and a holding hole 320b is formed near the other end for holding with a holding device (not shown) when adjusting the position of the lens support portion 320. Has been. As shown in FIGS. 5 and 6, when the lens support 320 is fixed to the fixing portion 311 of the LD support 310, the surface of the lens support 320 is orthogonal to the surfaces of the bottom plate 311a and the side plates 311b and 311c. To do. That is, the surface of the lens support part 320 is arranged in a direction substantially parallel to the surface of the holding part 312. At this time, the position of the support hole 320a of the lens support part 320 is substantially overlapped with the position of the support hole 312b of the holding part 312 in the Z-axis direction.

  As shown in FIG. 4, the slit plate 330 includes a bottom plate 330a having a length in the longitudinal direction substantially the same as the length in the short direction of the bottom plate 311a, and a length slightly shorter than the length in the short direction from one end in the short direction. It is comprised from the side plate 330b protrudingly provided by short width. The bottom plate 330a has a positioning hole 330c and a screw hole 330d corresponding to the positioning protrusion 311d and the screw hole 311e of the bottom plate 311a, respectively. Further, a slit hole 330e elongated in the X-axis direction is provided at a position corresponding to about half the length of the side plate 311b of the fixing portion 311 in the short direction from the edge of the side plate 330b on the bottom plate 330a side. Is provided. As shown in FIGS. 5 and 6, in the slit plate 330, the side plate 330b is bent in a substantially orthogonal direction with respect to the bottom plate 330a, positioned on the bottom plate 311a by positioning protrusions 311d, and the LD support unit 310 and the scanner together with screws 380. It is fixed to the frame 202. The LD support unit 310 is fixed to the scanner frame 202 by inserting a screw 380 into the screw hole 313 d of the bottom plate 313 b of the adjustment unit 313. Although not shown, the bottom plates 311a and 313b are provided with notches for positioning when the LD support portion 310 is fixed to the scanner frame 202. The slit plate 330 is a “slit member” in the present invention.

  Next, the attachment and adjustment of the laser unit 300 will be described with reference to FIGS. As shown in FIGS. 5 and 6, the laser unit 300 is bent into a valley fold with a broken line and a mountain fold with a one-dot chain line as shown in FIG. The LD 350 is press-fitted with the laser light emission direction aligned with the direction of the slit plate 330. The LD support unit 310 is fixed to the scanner frame 202 together with the slit plate 330 with screws 380. A screw 370 inserted from the adjustment hole 312d side of the holding portion 312 is tightened and temporarily fixed by the screw hole 313c.

  On the other hand, the collimator lens 360 is fitted and supported in the support hole 320a of the lens support part 320. The collimator lens 360 is supported by the lens support unit 320 such that the optical axis direction of the collimator lens 360 is orthogonal to the plate surface of the lens support unit 320. The collimating lens 360 corresponds to a “lens” in the present invention.

  And the lens support part 320 is hold | maintained by the holding | maintenance tool (not shown) by the holding hole 320b, the state which orient | assigned the plate | board surface in parallel with the opposing direction of the side plates 311b and 311c, ie, the optical axis direction of the collimating lens 360, The fixed portion 311 is positioned in a state substantially parallel to the Z-axis direction. Prior to this step, an adhesive is applied in advance to the opposing positions of the side plates 311b and 311c of the fixing portion 311 that face the cross section in the plate thickness direction when the lens support portion 320 is positioned. This adhesive is a known UV adhesive that cures when irradiated with UV light.

  By the way, in the production process of the scanner unit 200, it is better that the UV adhesive is applied to a vertical surface with a thickness of 1 to 2 mm before the lens support 320 is disposed at a predetermined position. Even when applied at this thickness, it is desirable that the UV adhesive has a viscosity that does not sag. For this reason, it is preferable that the thixo ratio of UV adhesive is 1.9-10. The thixo ratio is an index of so-called sag resistance. If the thixo ratio is 1.9 or more, the UV adhesive does not sag at a coating thickness of about 2 mm. It is known that the shape of the applied state is maintained within a time (for example, about 20 minutes) that may be left after application including the time required for the position adjustment operation. If the thixo ratio is 10 or less, when the lens support 320 is inserted into the UV adhesive application position, the UV adhesive is bonded to the lens support 320 (the lens support 320 facing the side plates 311b and 311c). In the vicinity including the cross section in the plate thickness direction, the UV adhesive is freely deformed even when the position of the lens support 320 is adjusted, and the force applied to the holding device is weak. Position adjustment can be easily performed. In addition, after the UV adhesive is cured, a sufficient adhesive force is obtained between the lens support portion 320 and the side plates 311b and 311c in the X, Y, and Z axis directions.

  Next, the optical axes of the LD 350 and the collimator lens 360 are aligned. This step is performed before the polygon mirror 220 is fixed to the scanner frame 202. In the optical axis alignment step, a predetermined voltage is applied to the LD 350 via the circuit board 204 (see FIG. 2), and laser light is emitted from the LD 350. Since the laser beam passes through the collimating lens 360 and the slit hole 330e and there is no polygon mirror 220 on the optical path, the laser beam is emitted to the outside through the inspection hole 202c of the scanner frame 202, and a measuring instrument (not shown) installed there Is incident. And it is measured by the measuring device whether the optical axis of LD350 and the collimating lens 360 is adjusted correctly. Based on the measurement result, the position of the lens support 320 is moved in the X-axis direction and the Y-axis direction by a holding tool (not shown), and the optical axis is adjusted. Although the uncured UV adhesive is in contact with the lens support portion 320, as described above, the force applied to the holding device by the UV adhesive is weak and does not hinder its operation. Position adjustment of the part 320 is not hindered. Therefore, the position of the lens support 320 can be adjusted from the target adjustment position to a level within several μm, for example, with a sufficient margin with respect to the allowable adjustment deviation range (for example, less than 10 μm). As described above, the width B in the short direction of the lens support portion 320 is 100 μm or more narrower than the width A in the short direction of the bottom plate 311a, and the position of the lens support portion 320 in the X-axis direction. Can be adjusted. When this optical axis alignment is performed, the lens support 320 is arranged so that the distance in the optical axis direction between the LD 350 and the collimating lens 360 is within a predetermined range that can be adjusted by the movement of the holding unit 312 described later. The

  When the optical axes of the LD 350 and the collimating lens 360 are adjusted within a few μm, the UV adhesive is irradiated with UV light and cured. At this time, since the material of the laser unit 300 is bright aluminum, the irradiated UV light is reflected on each surface of the laser unit 300. As a result, the amount of UV light that hits the UV adhesive increases, so that the UV curing speed increases, and in this embodiment, it is sufficiently cured in about 10 seconds. In this way, the lens support part 320 is fixed to the fixing part 311 of the LD support part 310.

  In addition, glass beads are mixed in the UV adhesive as an anti-shrinkage agent. Note that the shrinkage inhibitor may be glass powder or mica. As a result, the rate of reduction of the volume when the UV adhesive is cured is reduced, so that deviation after the optical axis adjustment of the LD 350 and the collimating lens 360 is less likely to occur, and it is well within the allowable range of adjustment deviation. Can do.

  Next, a screwdriver or the like is inserted through the circuit board 204 and the through hole 202d (see FIG. 3) of the scanner frame 202, and the screw 370 is turned. As a result, the holding portion 312 makes use of the lever property with the connection portion 314 to the side plate 311b as a fulcrum, the position of the adjustment hole 312d as the force point, and the position of the support hole 312b of the LD350 as the action point, The relative position of the lens 360 in the optical axis direction is adjusted. Since the amount of movement at the force point and the amount of movement at the action point are proportional to the ratio of the distance from the fulcrum, the force point position is greatly moved at the force point set so that the distance from the fulcrum is farther than the action point. Even if it makes it, the movement of an action point can be made small. Therefore, by adjusting the distance between the extended end 312a of the holding portion 312 and the side plate 313a by the rotation of the screw 370, the distance between the LD 350 and the collimating lens 360 that requires final adjustment at a sufficient level of 1 μm or less can be obtained. Fine adjustments can be made. The position of the LD 350 is adjusted in the + Z direction by tightening the screw 370. When the screw 370 is loosened, the distance between the extended end portion 312a of the holding portion 312 and the side plate 313a that are opposed to each other so as not to come into contact with each other is increased. Since the aluminum plate is elastically restored, the position of the LD 350 is adjusted in the −Z direction. In addition, since the adjustment hole 312d is an oval having a long axis in the X-axis direction, a large movement in the vertical direction (Y-axis direction) of the holding portion 312 is restricted by the screw 370, and even if a deviation occurs. The deviation is prevented so as to be within the allowable range of the adjustment deviation.

  After the relative position adjustment between the LD 350 of the laser unit 300 and the collimating lens 360 is completed in this way, the polygon mirror 220 is disposed on the scanner frame 202 and is fixed to the tray 203, and then is almost sealed by the upper lid member 201. And fixed between the left and right body frames (not shown) of the laser printer 1. In addition, since the LD support part 310 and the lens support part 320 of the laser unit 300 are made of the same material, they have the same linear expansion coefficient, and are affected by temperature changes from the surrounding environment (for example, due to heat generation of the LD 350). In addition, since the LD support portion 310 and the lens support portion 320 expand at the same ratio, the adjusted position can be stably maintained.

  Next, the operation at the time of printing of the laser printer 1 will be described with reference to FIGS. The uppermost sheet 3 stacked on the sheet pressing plate 7 of the sheet feeding cassette 6 is pressed toward the sheet feeding roller 8 by a spring 7 b from the back side of the sheet pressing plate 7. When printing is started based on reception of print data from a host computer (not shown), the paper 3 is fed by the frictional force between the paper feed roller 8 and the paper feed roller 8 and the separation pad 9. It is sandwiched between. The sheet 3 separated into single sheets is sent to a registration roller 12.

  On the other hand, in the scanner unit 200, the laser light emitted from the LD 350 of the laser unit 300 based on the laser drive signal generated by the engine board 85 is collimated into substantially parallel light by the collimating lens 360, and the light flux is emitted from the slit hole 330e. The spread is restricted, the image is refracted in the vertical direction by the cylindrical lens 210 and imaged on the polygon mirror 220. The polygon mirror 220 scans the laser beam in the horizontal direction and reflects the laser beam to the fθ lens 230. The laser beam scanned at a constant angular velocity is converted into a constant linear velocity scan when passing through the fθ lens 230, and the vertical surface tilt caused by the polygon mirror 220 is corrected by the cylindrical lens 260 via the mirrors 240 and 250. Further, an image is formed on the surface of the photosensitive drum 27 via the mirror 270.

  Further, the surface potential of the photosensitive drum 27 is charged to, for example, about 1000 V by the scorotron charger 29. Next, the photosensitive drum 27 rotating in the direction of the arrow (clockwise in the figure) is irradiated with laser light. The laser beam is emitted on the main scanning line of the paper 3 so that the portion to be developed is irradiated and the portion not to be irradiated is not irradiated, and the surface potential of the portion irradiated with the laser beam (bright portion) is For example, it drops to about 200V. Then, the rotation of the photosensitive drum 27 irradiates the laser beam in the sub-scanning direction (the conveyance direction of the paper 3), and the surface of the photosensitive drum 27 is divided into a portion where the laser beam is not irradiated (dark portion) and a bright portion. An electrically invisible image, that is, an electrostatic latent image is formed thereon.

  The toner in the toner hopper 34 is supplied to the supply roller 33 by the rotation of the agitator 36, and then supplied to the developing roller 31 by the rotation of the supply roller 33. At this time, the toner is positively frictionally charged between the supply roller 33 and the developing roller 31, and further, is adjusted so as to be a thin layer having a constant thickness and is carried on the developing roller 31. A positive bias of about 400 V is applied to the developing roller 31. By the rotation of the developing roller 31, the positively charged toner carried on the developing roller 31 is statically formed on the surface of the photosensitive drum 27 when coming into contact with the photosensitive drum 27. Transition to an electrostatic latent image. That is, since the potential of the developing roller 31 is lower than the dark portion potential (+1000 V) and higher than the light portion potential (+200 V), the toner selectively transfers to the light portion having a low potential. In this way, a visible image as a developer image is formed on the surface of the photosensitive drum 27, and development is performed.

  The registration roller 12 registers the sheet 3 and feeds out the sheet 3 at a timing when the leading edge of the visible image formed on the surface of the rotating photosensitive drum 27 coincides with the leading edge of the sheet 3. Then, when the sheet 3 passes between the photosensitive drum 27 and the transfer roller 30, the transfer roller 30 is set so that the potential of the transfer roller 30 becomes lower (for example, about −1000 V) than the potential of the bright portion (+200 V). By applying a negative constant current to 30, the visible image formed on the surface of the photosensitive drum 27 is transferred onto the paper 3.

  Then, the sheet 3 on which the toner has been transferred is conveyed to the fixing device 18. The fixing device 18 applies heat of about 200 ° C. by the fixing roller 41 and pressure by the pressure roller 42 to the paper 3 on which the toner is placed, and fuses the toner onto the paper 3 to form a permanent image. The fixing roller 41 and the pressure roller 42 are grounded via diodes, respectively, so that the surface potential of the pressure roller 42 is lower than the surface potential of the fixing roller 41. Therefore, the positively charged toner placed on the fixing roller 41 side of the sheet 3 is electrically attracted to the pressure roller 42 via the sheet 3, so that the toner is attracted to the fixing roller 41 during fixing. This prevents the image from being disturbed.

  The sheet 3 on which the toner is fixed by heating and heating is discharged from the fixing unit 18 by the transport roller 43, transported on the paper discharge path 44, and discharged to the paper discharge tray 46 with the print surface facing downward by the paper discharge roller 45. Is done. Similarly, the sheet 3 to be printed next is stacked on the sheet discharge tray 46 with the printing surface facing down on the previously discharged sheet 3. Thus, the user can obtain the sheets 3 arranged in the printing order.

  As described above, the laser unit 300 according to the present embodiment supports the LD 350 on the LD support part 310 formed from one bright aluminum plate, and holds the lens support part 320 that supports the collimating lens 360. It hold | maintains with an instrument and it inserts between the side plates 311b and 311c of LD support part 310 to which UV adhesive agent was previously applied. Before the lens support 320 is fixed, the optical axes of the LD 350 and the collimator lens 360 are adjusted in the X and Y directions, and UV light is irradiated and fixed while maintaining the adjustment position. Next, in a state where the collimator lens 360 is fixed, the holding portion 312 uses the connection portion 314 with the side plate 311b as a fulcrum, the position of the adjustment hole 312d as a power point, and the position of the support hole 312b of the LD350 as an action point. By utilizing the property, the LD 350 can be finely moved in the optical axis direction to adjust the relative position of the LD 350 and the collimating lens 360 in the optical axis direction. Since the extended end 312a and the side plate 313a, which are tightened with screws when adjusting the relative position in the optical axis direction, are not in surface contact, they are freed from distortion that easily occurs between the contact surfaces during fastening. Therefore, the optical axis is not displaced due to distortion, and the adjusted position can be stably maintained.

Further, since the LD support unit 310 and the lens support unit 320 are made of the same material, they have the same linear expansion coefficient, and the lens center of the collimator lens 360 is configured to be at the center of the lens support unit 320. Even if the laser unit 300 is thermally expanded due to the influence of heat generated by the LD 350, the adjusted optical axis direction can be stably maintained because there is no difference in expansion between components. Further, since the LD support part 310 and the lens support part 320 are made of aluminum, the linear expansion coefficients of the resin scanner frame 202 mixed with the reinforcing agent and the LD support part 310 and the lens support part 320 are substantially equal. Therefore, even if thermal expansion occurs, there is no difference in expansion between components, and the adjusted optical axis direction can be stably maintained. In addition, the linear expansion coefficient of the LD support part 310 and the lens support part 320 formed of aluminum is 2.3 × 10 ⁻⁵ / K. Further, for example, the linear expansion coefficient of a resin such as PC (polycarbonate) or modified PPE (resin in which polyphenylene ether is modified with polystyrene) is 6 to 8 × 10 ⁻⁵ / K, and this is mixed with a reinforcing agent such as glass fiber. The linear expansion coefficient of the scanner frame 202 formed in this way is 1.8 to 3.5 × 10 ⁻⁵ / K.

  Needless to say, the present invention can be modified in various ways. For example, the side plate 311c of the fixing portion 311 of the LD support portion 310 of the laser unit 300 is preferably the same size as the side plate 311b, and the side plates 311c and 311b only need to be substantially parallel. Further, a slit may be provided in the lens support part 320 without providing the slit plate 330. Further, the adjustment hole 312d of the holding portion 312 of the LD support portion 310 is oval, but may be circular. Further, the collimating lens 360 may be directly bonded and fixed to the side plates 311c and 311b without using the lens support portion 320.

  In addition, the collimator lens 360 is fixed in a cylindrical lens barrel formed of a resin mixed with a compound having a high thermal conductivity so as to be approximately equal to the linear expansion coefficient of aluminum, and it is difficult to touch the lens during production. However, the handling may be easy. In this case, since the linear expansion coefficients of the lens barrel and the lens support portion 320 are substantially equal, even when the lens support portion 320 supporting the lens barrel is affected by heat due to, for example, the heat generated by the LD 350, the collimating lens. The portion around 360 is thermally expanded almost uniformly, and it is possible to make it difficult to affect the lens center. In this case, the lens barrel to which the collimating lens 360 is fixed corresponds to the “lens holder” in the present invention. The slit may be provided in the lens barrel.

  Further, as shown in FIG. 7, the force point of the holding portion 312 may be provided on the side opposite to the action point with respect to the fulcrum. That is, with the connecting portion 314 between the side plate 311b of the fixing portion 311 and the holding portion 312 as a fulcrum, the side plates 390 and 391 are spaced apart from each other by a predetermined distance in the direction opposite to the extending direction of the holding portion 312. Extend approximately parallel. Then, by using the vicinity of the projecting ends of the side plates 390 and 391 as a power point and moving them closer or away by a screw 370, the holding portion 312 in the same plane as the side plate 390 is interlocked with the connection portion 314 as a fulcrum, The LD 350 can be separated or close to the collimating lens 360. Further, as shown in FIG. 8, a slit plate 330 is separately provided in the configuration of the laser unit 300, the LD support 350 is supported by the lens support portion 320, and the collimator lens 360 is supported by the holding portion 312 of the LD support portion 310. May be. In this case, the optical axis alignment and the relative position adjustment method in the optical axis direction are the same as in this embodiment, and the laser light is emitted in the + Z direction.

  Also, the surface of the laser unit 300 has been subjected to a brilliant process, but it may be a high-gloss process. You may form from a board or another metal plate.

  Further, the LD support part 310 and the lens support part 320 may be molded from resin or the like. Or you may comprise from the mixed components of a metal and resin. Or you may comprise from other materials. In this case, among the parts constituting the laser unit 300, in particular, the holding part 312, the fixing part 311, and the lens support part 320 may be molded from a material having a thermal conductivity of 0.9 W / (m · K) or more. desirable. In general, the thermal conductivity of metals is high, and that of resins is low. However, when some parts are molded from resin, distortion between parts due to the difference in linear expansion coefficient can be reduced by using a material that is as close to the thermal conductivity of the metal as possible. A general resin has a thermal expansion coefficient of 0.2 to 0.3 W / (m · K), but an epoxy resin having a thermal conductivity of 0.96 W / (m · K) was developed by Hitachi, Ltd. ing. By using such a resin, heat generated from the LD 350 can be efficiently dissipated, the LD 350 can be operated in a thermally stable manner, and uneven emission of the LD 350 can be reduced.

FIG. 1 is a central sectional view of the laser printer 1. FIG. 2 is a perspective view of the scanner unit 200 as viewed from above with the upper lid member 201 removed. FIG. 3 is a perspective view of the scanner unit 200 viewed from an angle different from that of FIG. 2 with the upper cover member 201 removed. FIG. 4 is a development view of the laser unit 300. FIG. 5 is a perspective view showing the laser unit 300. FIG. 6 is a perspective view showing the laser unit 300 viewed from an angle different from that in FIG. FIG. 7 is a view showing a modification of the laser unit 300. FIG. 8 is a view showing a modification of the laser unit 300.

DESCRIPTION OF SYMBOLS 1 Laser printer 200 Scanner unit 202 Scanner frame 220 Polygon mirror 221 Motor 230 f (theta) lens 240,250,270 Mirror 260 Cylindrical lens 300 Laser unit 310 LD support part 311 Fixing part 311b, 311c Side plate 312 Holding part 312a Extension end part 313 Adjustment Part 314 Connection part 320 Lens support part 330 Slit plate 350 Laser diode (LD)
360 collimating lens 370 screw

Claims (9)

A first support plate for supporting a lens holder for holding a lens;
A second support plate that supports the light source so as to face the first support plate;
In order to fix the first support plate with an adhesive while being disposed in between, a first fixing plate and a second fixing which are arranged perpendicular to the first support plate and parallel to each other The board,
An adjustment plate arranged vertically connected to the second fixed plate;
A connecting portion for vertically connecting the first fixing plate and the second support plate;
The second support plate is moved relative to the first support plate with the connecting portion as a fulcrum and the portion of the second support plate facing the adjustment plate as a power point, and the lens, the light source, An optical member holding means comprising: an adjusting means for adjusting the position of the optical member. The lens holder, the optical member holding device according to claim 1, characterized in that it is composed of a member having a linear expansion coefficient and equal correct linear expansion coefficient of the first support plate.   The distance from the lens center of the lens held by the lens holder to the end of the first support plate on the first fixed plate side, and the second fixed plate side of the first support plate 3. The optical member holding means according to claim 1, wherein the distance to the end is equal. A third fixing plate for connecting the first fixing plate and the second fixing plate;
The optical member holding device according to any one of claims 1 to 3, wherein the third fixing plate is provided with a slit member configured to stop a light beam emitted from the light source and passing through the lens. means.   The optical member holding means according to any one of claims 1 to 3, wherein the lens holder is provided with a slit member that stops a light beam emitted from the light source and passing through the lens. Optical member holding means according to any one of claims 1 to 3 and 5,
A rotating polygon mirror that performs scanning by changing the reflection direction of the light beam emitted from the optical member holding means;
Driving means for rotating the rotary polygon mirror;
Imaging means for forming an image of the light beam scanned by the rotary polygon mirror on the imaging medium;
An optical scanning device comprising: the optical member holding unit; the rotary polygon mirror; the driving unit; and a frame that houses the imaging unit. The optical member holding means according to claim 4,
A rotating polygon mirror that performs scanning by changing the reflection direction of the light beam emitted from the optical member holding means;
Driving means for rotating the rotary polygon mirror;
Imaging means for forming an image of the light beam scanned by the rotary polygon mirror on the imaging medium;
A frame for housing the optical member holding means, the rotary polygon mirror, the driving means, and the imaging means;
An optical scanning device comprising: Before Symbol third fixing plate includes an optical scanning apparatus according to claim 7, characterized in that fixed to the frame. The optical scanning device according to any one of claims 6-8 wherein the frame is characterized in that it is molded from resin toughener was mixed.

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