JP5220521B2 - Image forming apparatus - Google Patents

Description

The present invention is a copying machine, a printer, relates to an image forming equipment of a facsimile apparatus or the like, and more particularly to an image forming apparatus which enables position adjustment of the optical housing.

  With reference to FIGS. 13 and 14, an example of a conventional optical scanning device 500 (this will be referred to as Conventional Technology 1) will be described. However, FIG. 13 is a plan view showing the arrangement of the main optical components and the optical path of the light beam of the optical scanning device, and FIG. 14 is a schematic sectional view showing the arrangement of the main optical components of the optical scanning device and the optical path of the light beam. .

  First, the configuration of the optical system of the optical scanning device 500 will be described.

  As shown in FIG. 13, the optical scanning device 500 basically includes a semiconductor drum 521, and a photosensitive drum, which is a scanned object, by a polygon mirror 520 that receives and reflects the laser light emitted from the semiconductor laser 521. An apparatus for scanning a light beam on 700.

  Various optical components are arranged on the optical path from the semiconductor laser 521 to the polygon mirror 520 (hereinafter referred to as the first optical path) and the optical path from the polygon mirror 520 to the photosensitive drum 700 (hereinafter referred to as the second optical path). ing. Here, the optical component disposed in the first optical path is referred to as an emission optical system, and the optical component disposed in the second optical path is referred to as a scanning optical system.

  The emission optical system includes a semiconductor laser 521 that emits laser light, a collimator lens 522 that converts the emitted laser light into parallel light, and the width direction of the parallel laser light that has passed through the collimator lens 522 (ie, the scanning direction). A concave lens 522 (in FIG. 13, the collimator lens and the concave lens are denoted by the same reference number), an aperture plate 526 for narrowing the laser light transmitted through the concave lens 522 into a rectangular beam, and an aperture plate 526 The cylindrical lens 527 is configured to focus on the polygon mirror 520 in the vertical direction of the laser light that has passed through the opening. The semiconductor laser 521, the collimator / concave lens 522, and the aperture plate 526 are incorporated in the same lens barrel so as to be movable and adjustable.

  As shown in FIG. 14, the scanning optical system has a plurality of reflecting surfaces around the rotation axis, and rotates around the rotation axis, so that the laser light incident from the emission optical system is changed in the main scanning direction ( A polygon mirror 520 that scans in the direction along the axis of the photosensitive drum 700), and two fθ lenses 523a that shape a laser beam to eliminate spherical aberration on the scanning surface of the photosensitive drum 700, 523b and a folding mirror 524 that reflects the laser light transmitted through the fθ lenses 523a and 523b onto the photosensitive drum 700.

  The exit optical system and the scanning optical system are fixed to a predetermined position of an integrally formed optical casing 531, and the optical casing 531 is positioned and adjusted with respect to an apparatus frame (not shown) of the image forming apparatus. And it is positioned and fixed by the holding member.

  This positioning adjustment and holding member is constituted by one reference hole 601 and four mounting holes 602 to 605. In other words, a reference hole 601 is formed at the tip (photosensitive drum 700 side) of one side surface 533 (the lower side surface in FIG. 13) of the outer peripheral surface 532 of the optical casing 531, and the rear of the reference hole 601. Mounting holes 602 to 605 are respectively formed at a total of four locations, two on the front side (polygon mirror 520 side) and two on the opposite side surface 534. The reference hole 601 is inserted and supported by a support pin (not shown) provided in the apparatus frame of the image forming apparatus, and each mounting hole 602 to 605 is inserted into a bolt screw rod (not shown) provided in the apparatus frame of the image forming apparatus. The optical casing 531 is supported and fixed to the apparatus frame of the image forming apparatus by attaching a nut (not shown) to the bolt screw rod.

  In this case, each of the mounting holes 602 to 605 is formed in a long hole along the irradiation direction of the laser light (the direction indicated by the symbol X1 in FIG. 13). Therefore, after inserting the mounting holes 602 to 605 through the bolt screw rods, the attitude of the optical casing 531 can be adjusted by slightly rotating the optical casing 513 around the reference hole 601 in the Y direction in FIG. It has become.

  That is, when the laser light is irradiated in a state where the reference hole 601 is inserted and supported by the support pin and each of the mounting holes 602 to 605 is inserted into the bolt screw rod and fixed by the nut, the irradiated light is applied to the photosensitive drum 700. In FIG. 13, when the reference scanning line indicated by reference numeral L1 is scanned, it is attached correctly. However, if it is scanned slightly tilted as indicated by reference numeral L2 in FIG. Once loosened, the entire optical housing 531 is parallel to the surface of the spatial region through which the laser beam deflected by the polygon mirror 520 passes in the Y1 direction in FIG. By slightly shifting (rotating) in the horizontal direction, the scanning line L2 can coincide with the reference scanning line L1. That is, the attitude of the optical housing 531 can be finely adjusted. After this fine adjustment, the optical casing 231 can be fixed in an appropriate posture by tightening the nut again.

  On the other hand, in addition to such adjustment by one reference hole and four mounting holes, an optical scanning apparatus that can appropriately adjust the attitude of the optical scanning apparatus with respect to the scanning target (photosensitive drum) is proposed. (For example, refer to Patent Document 1).

As shown in FIG. 15, this optical scanning device is provided with swinging fulcrums P11 and P12 of the optical scanning device 822 at two points on a straight line K81 obliquely intersecting the axis 800a of the rotatable object 800 to be scanned. At one point S81 (adjustment point) on another straight line L81 orthogonal to the straight line K81, an attitude adjusting unit of the optical scanning device 822 is provided, and the optical scanning device 822 is moved with respect to the scanned object 800 by the attitude adjusting unit. The posture can be adjusted in the twist direction.
JP 2002-258198 A

  In the above prior art 1, when the optical scanning device in which the inclination of the optical axis is adjusted with respect to the irradiation surface of the scanned object alone is attached to the image forming apparatus, the photosensitive drum as the irradiation surface is inclined. The optical scanning device must be tilted and adjusted in accordance with the photosensitive drum. However, in the optical scanning device of the prior art 1, when the horizontal rotation is performed with reference to the end of one side surface of the optical housing in the adjustment, the conjugate length to the photosensitive drum is increased at the end of the other side surface. There is a problem that the resolution is deteriorated and the difference in resolution from the end portion having the reference hole is increased. Further, in the optical scanning device of the above-described prior art 1, the scanning optical system is provided with the folding mirror 524, and the laser beam irradiated from the polygon mirror 520 is folded (reflected) to be a photosensitive drum as a scanning target. It has a structure to irradiate. Therefore, the posture adjustment of the optical scanning device 500 is parallel to the surface of the spatial region that passes when the laser light deflected by the polygon mirror 520 is scanned (hereinafter referred to as a laser light irradiation surface or a laser irradiation surface). Although it is possible to rotate in the horizontal direction, when the laser beam emitted from the polygon mirror 520 is irradiated to the scanning object in a straight line without being folded halfway, the scanning line in the rotation in the horizontal direction is possible. There was a problem that it was not possible to adjust the deviation. Further, since the folding mirror is provided, there is a problem that the manufacturing cost increases.

  Further, in the optical scanning device of the above-mentioned Patent Document 1, adjustment is not easy because it is adjusted so as to be swingable in the torsional direction with respect to the photosensitive drum around two swing support points P11 and P12 provided on the casing. There was a problem.

The present invention has been devised to solve such problems, and its purpose is to provide a positioning axis as a fulcrum for adjustment at the center of the tip of the optical housing, and center the positioning axis with respect to the laser irradiation direction. Te be to slightly rotate in the vertical direction is to provide a picture image forming apparatus that can be easily performed posture adjustment of the optical scanning device.

In order to solve the above problems, an image forming apparatus of the present invention forms an image of a light source that emits laser light, a rotating polygon mirror that deflects and scans laser light from the light source, and laser light deflected by the rotating polygon mirror. An image forming apparatus provided with an optical scanning device in which an imaging lens for irradiating a scanning surface of a scanned object is provided in an optical housing, wherein the optical housing is rotatable relative to the image forming device main body. One positioning shaft to be mounted and two mounting holes to be positionally adjustable with respect to the image forming apparatus main body are formed, and the positioning shaft is an irradiation surface of a laser beam deflected and scanned by the rotary polygon mirror. provided in the irradiation direction central portion, said two attachment holes, said respective provided other two points the position of the triangle whose vertices positioning shaft Rutotomoni, shape drawing a rotation locus around the positioning shaft In the long hole Made is, the two by adjusting the mounting position relative to the image forming apparatus main body of the mounting hole the optical housing by rotating about said positioning axis, the scanning target attached to the image forming apparatus main body The optical housing is provided so as to be adjustable in posture. In this case, the positional relationship between the center of the positioning shaft and the centers of the two mounting holes is preferably an isosceles triangular relationship with the center of the positioning shaft as a vertex. Further, the optical casing is provided so as to be rotatable (rotatable) about the positioning axis .

According to the image forming apparatus of the present invention, a positioning shaft serving as a fulcrum for adjustment is provided at the center of the tip of the optical casing, and the position can be adjusted at the other two points of the triangle having the positioning shaft as a vertex. By providing each hole, the posture adjustment of the optical scanning device is facilitated. That is, when the irradiation direction (scanning line) of the light beam to the scanning surface of the photosensitive drum as the scanning object is deviated from the reference scanning line, the attachment position of the attachment hole may be shifted according to the deviation direction. . That is, the direction in which the mounting hole is displaced is the direction in which the irradiation direction (scanning line) of the light beam is rotated so as to coincide with the reference scanning line. Since it is sufficient to shift the mounting hole with a sense, it is possible to intuitively grasp the direction of shifting. This facilitates the posture adjustment of the optical scanning device.

  In this case, it is preferable that the two attachment holes are arranged so that a line connecting the centers thereof is parallel to the laser light irradiation surface. More preferably, when the centers of the two mounting holes and the center of the positioning shaft are projected in a direction perpendicular to the irradiation direction of the laser light, the centers are positioned on a straight line. Thus, by providing so that it may be located on a straight line, the thickness of an optical housing | casing can be made thin and the arrangement space of an optical scanning device can be reduced. That is, it can contribute to downsizing of the image forming apparatus. The center of the positioning axis is preferably located on a vertical plane passing through the center of the optical axis of the laser irradiation surface.

In the image forming apparatus of the present invention, in the optical housing, the positioning shaft is provided on the imaging lens side, and the attachment hole is provided on the rotary polygon mirror side. That is, the positioning shaft is disposed so as to face the scanning surface of the photosensitive drum that is the body to be scanned, and the two mounting holes are disposed on the rear side as viewed from the scanning surface of the photosensitive drum. As a result, the side closer to the scanning surface of the photosensitive drum serves as a support point for rotation, so that blurring when the optical casing is rotated can be reduced.

In the image forming apparatus of the present invention, the laser beam deflected by the rotary polygon mirror passes through the imaging lens and is then irradiated to the scanned object without being reflected. In other words, the scanning optical system from the rotary polygon mirror to the scanning object is configured to irradiate the laser beam in a straight line without reflecting it halfway. With such an arrangement, it is possible to save the arrangement space of the optical scanning device, and thus contribute to the downsizing of the image forming apparatus.

The image forming apparatus of the present invention, prior to SL and one of the scale indicating a mark or position adjustment amount to the mounting portion of the optical housing mounting hole is formed is provided, opposite to the mounting portion The apparatus frame may be configured such that the mark or the other scale indicating the position adjustment amount is provided. Or the scale which shows a position adjustment amount is provided in the attachment part of the said optical housing | casing in which the said attachment hole was formed, and it is good also as a structure by which the mark was provided in the said apparatus frame facing this attachment part. By adopting such a configuration, when adjusting the attitude of the optical housing, it is possible to visually read how much adjustment should be made from the mark and scale, so that it is possible to easily adjust the attitude. Become.

  According to the present invention, a positioning shaft serving as a fulcrum for adjustment is provided at the center of the tip of the optical housing, and mounting holes capable of position adjustment are provided at two other points of the triangle having the positioning shaft as a vertex. Thus, the posture adjustment of the optical scanning device can be easily performed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

11 and FIG. 12 is an overall configuration diagram of images forming apparatus of the present invention, FIG. 11 is cross-sectional view, FIG. 12 is a detailed view of the surrounding photosensitive drum.

  The image forming apparatus 1 according to the present embodiment is connected to a scanner 2, an automatic document conveying device 4, a sheet post-processing device 5, a multistage sheet feeding unit 6, and a relay conveying unit 8, with a printer 2 as a center. Expansion has been done.

  The scanner 3 is disposed above the printer 2 and the sheet post-processing device 5 by being supported on the system rack 7 together with the automatic document feeder 4 disposed on the scanner 3.

  Hereinafter, each device will be outlined briefly.

  The printer 2 records and outputs an image read by the scanner 3 and records and outputs image data from the externally connected device when an image processing apparatus (externally connected device) such as a personal computer is connected. It is. In the printer 2, an electrophotographic process unit 20 having a drum-shaped photosensitive drum 200 as the center is disposed on the substantially central right side of the image forming apparatus main body.

  As shown in FIG. 12, around the photosensitive drum 200, a charging roller 201 for uniformly charging the surface of the photosensitive drum 200, and a light image is scanned on the uniformly charged photosensitive drum 200 for electrostatic charging. An optical scanning device 22 that writes a latent image, a developing unit 202 that visualizes the electrostatic latent image written by the optical scanning device 22 with a developer, and an image that is stored and reproduced on the photosensitive drum 200 is printed on paper. The transfer unit 203 for transferring the image onto the photosensitive drum 200, the developer remaining on the photosensitive drum 200 is removed, and a new image can be recorded on the photosensitive drum 200, and the photosensitive drum 200. A static elimination lamp unit (not shown) for removing surface charges is sequentially arranged.

  The optical scanning device 22 includes a semiconductor laser 221 (see FIG. 12), a polygon mirror 220 that reflects laser light from the semiconductor laser 221, and laser light reflected by the polygon mirror 220 on the photosensitive drum 200 at constant speed. Two fθ lenses 223 (223a, 223b) and the like that function as described above are incorporated.

  The semiconductor laser 221 irradiates a laser beam in accordance with image data read by the scanner 3 described later and stored in an image memory, or image data transferred from an externally connected device such as a personal computer or a facsimile terminal. An electrostatic latent image corresponding to the image data is formed on the drum 200.

  Below the printer 2 main body, a paper supply unit 21 is disposed inside the printer 2 main body. The sheet supply unit 21 includes a sheet storage tray 210 that stores sheets, and a separation supply unit 211 that separates and supplies the sheets stored in the sheet storage tray 210 one by one. The sheets supplied separately one by one from the sheet supply unit 21 are sequentially supplied between the photosensitive drum 200 and the transfer unit 203 of the electrophotographic process unit 20, and an image recorded and reproduced on the photosensitive drum 200 is transferred. Is done. The paper supply to the paper supply unit 21 is performed by pulling out the paper storage tray 210 to the front side of the printer 2 main body.

  On the lower surface of the printer 2 main body, paper fed from a multi-stage paper feeding unit 6 or the like prepared as a peripheral device is received, and sequentially between the photosensitive drum 200 and the transfer unit 203 of the electrophotographic process unit 20. A paper receiving opening 27 for supplying is provided.

  A fixing device 23 is disposed above the electrophotographic process unit 20, and sequentially receives the paper on which the image has been transferred, heats and fixes the developer transferred onto the paper, and loads the paper out of the fixing device 23. Send it out.

  The sheet on which the image is recorded is transferred from the discharge roller 28 of the printer 2 to the relay conveyance unit 8 on the upper surface of the printer 2 body.

  In the upper and lower space of the optical scanning device 22, a process control unit (PCU) substrate that controls the electrophotographic process, a printer control unit 24 that accommodates an interface substrate that receives image data from an external connection device, and an interface substrate are received. An image control unit 25 having an image control unit (ICU) substrate for performing predetermined image processing on the obtained image data and causing the optical scanning device 22 to scan and record as an image, and various substrates and units A power supply unit 26 for supplying power is disposed.

  The multi-stage paper feeding unit 6 is an external paper feeding device, and separates the paper stored in the paper storage tray 610 one by one by the separating and feeding means 611, and the paper of the printer 2 provided on the upper surface of the unit. The paper is supplied toward the paper discharge port 62 communicating with the receiving port 27. In the image forming apparatus of this example, the three sheet supply units 61, 61, 61 are arranged in a three-tiered state, and the sheet supply unit 61 that stores a desired sheet is selectively operated during operation. To do. The paper supply to the paper supply unit 61 is performed by pulling out the paper storage tray 610 to the front side of the unit main body.

  The multi-stage sheet feeding unit 6 is configured to place the printer 2 and the sheet post-processing apparatus 5 on the upper part thereof. However, the multi-stage sheet feeding unit 6 can be moved and fixedly placed between the system racks 7 in this state. The moving roller 63 and the fixed part 64 are provided at the lower part. At the time of movement, the fixing portion 64 is rotated and raised to separate the fixing portion 64 from the floor surface, and at the time of fixing, the fixing portion 64 is rotated and lowered to bring the fixing portion 64 into contact with the floor surface, so The paper feed unit 6 is fixed. The image forming apparatus according to the present embodiment is described as an apparatus in which three paper supply units 61 are stacked. However, there are various types such as a multi-stage paper feed unit including at least one or more paper supply units 61. There are things.

  The sheet post-processing device 5 performs post-processing on the paper by feeding the paper on which the image discharged from the relay conveyance unit 8 or the printer 2 is recorded at the upper part of the device with a pair of carry-in rollers 50. is there.

  As post-processing, there are stapling processing, sorting processing, and the like. The image forming apparatus of this example includes three paper discharge trays 51 (51a to 51c), and switches the gates 52 and 53 as necessary. Then, the paper discharge tray 51 for discharging the paper is selected. For example, the upper discharge tray 51a is used for discharging sheets in the copy mode, the middle discharge tray 51b is used for discharging sheets in the print mode, and the lower discharge tray 51c is used in the facsimile print mode. For example, it can be used for paper discharge, and can be discharged according to usage.

  The scanner 3 automatically supplies a sheet document by the automatic document feeder 4, and automatically reads and scans the documents one by one to read the document image, and the book document or the automatic document feeder 4. A manual reading mode in which a sheet document that cannot be automatically supplied is set by manual operation and a document image is read. Then, the image of the document set on the transparent document placing table 30 is exposed and scanned by the first scanning unit 31 and the second scanning unit 32 that move along the document placing table 30 with a predetermined speed relationship with each other. The original image is converted into an electrical signal and output by being guided by an optical component such as a mirror or an imaging lens 33 and forming an image on the photoelectric conversion element 34.

  The automatic document conveying device 4 includes a document conveying means 41 that conveys a document placed on the document setting tray 40 toward the document placing table 30 and discharges the scanned document onto a document discharge tray 42. Yes. Further, the automatic document feeder 4 can be rotated upward with the back side of the image forming apparatus as a fulcrum so that a sheet document that cannot be automatically fed can be placed on the document table 30 and scanned. As described above, the front side of the image forming apparatus is configured to be opened.

  The relay conveyance unit 8 is mounted on an upper portion of a paper discharge tray 9 provided on the top of the printer 2, and a sheet post-processing device 5 positioned on the downstream side of the printer 2 is used for recording a sheet on which an image discharged from the printer 2 is recorded. It is the conveyance unit for introducing toward. Further, another sheet for guiding the sheet from the middle of the sheet conveyance path 84 of the relay conveyance unit 8 to the sheet discharge tray 9 formed by the upper surface 82 of the relay conveyance unit 8 and the upper surface 54 of the sheet post-processing apparatus 5. The conveyance path 83 is branched. The two paper transport paths 83 and 84 can be selected by switching a gate 81 arranged at a branch portion of the paper transport path.

  Next, an embodiment of the optical scanning device 22 of the present invention will be described in detail with reference to FIG. However, FIG. 1A is a schematic plan view showing the arrangement of main optical components of the optical scanning device 22 and the optical path of the light beam, and FIG. 1B shows the optical device 22 viewed from the photosensitive drum 200 side. FIG. 2C is a schematic side view of the optical scanning device 22 as viewed from the side.

  First, the configuration of the optical system of the optical scanning device 22 will be described.

  As shown in FIG. 1, an optical scanning device 22 basically includes a semiconductor drum 221 and a polygon drum 220 that receives and reflects the laser beam emitted from the semiconductor laser 221 and is a photosensitive drum as a scanning target. 200 is a device that scans a light beam on 200. The polygon mirror 220 is a rotating polygon mirror having a plurality of reflecting surfaces in the rotation direction, and is a seven-sided body in this embodiment.

  Various optical components are arranged in the emission optical system from the semiconductor laser 221 to the polygon mirror 220 and the scanning optical system from the polygon mirror 220 to the photosensitive drum 200.

  The emission optical system includes a semiconductor laser 221 that emits laser light, a collimator lens 222 that converts the emitted laser light into parallel light, and a width direction of the parallel laser light that has passed through the collimator lens 222 (ie, the scanning direction). A concave lens 222 (in FIG. 1A, the collimator lens and the concave lens are indicated by the same reference number), an aperture plate 226 that narrows the laser light transmitted through the concave lens 222 into a rectangular beam, A cylindrical lens 227 for focusing the vertical direction of the laser beam that has passed through the opening of the aperture plate 226 on the polygon mirror 220 is configured.

  On the other hand, the scanning optical system has a plurality of reflecting surfaces around the rotation axis, and the polygon mirror 220 scans the laser light incident from the emission optical system in the main scanning direction by rotating around the rotation axis. And two fθ lenses 223a and 223b for shaping a laser beam to eliminate spherical aberration on the photosensitive drum 200 (that is, the image plane). That is, in the optical scanning device 22 of the present embodiment, the laser beam deflected by the polygon mirror 220 passes through the two fθ lenses 223a and 223b, and is then directly irradiated to the photosensitive drum 200 without being reflected. It is like that. That is, the scanning optical system from the polygon mirror 220 to the scanning surface of the photosensitive drum 200 is configured to irradiate the laser beam in a straight line in the horizontal direction without reflecting the laser beam halfway. With such an arrangement configuration, it is possible to save the arrangement space of the optical scanning device 22 and thus contribute to the downsizing of the image forming apparatus.

  The emission optical system and the scanning optical system are fixed to a predetermined position of an integrally formed optical casing 231. In other words, the exit optical system has one end side of the polygon mirror 220 arranged at the rear center of the rectangular optical casing 231 (in this embodiment, the lower end in FIG. 1A). Part). In addition, the scanning optical system is disposed at the center in the left-right direction (vertical direction in FIG. 1A) of the optical housing 231 formed in a rectangular shape.

The optical housing 231 in which the emission optical system and the scanning optical system are arranged in this way is positioned and adjusted and held with respect to an apparatus frame (not shown in FIG. 1) that is the main body of the image forming apparatus. It is positioned and fixed by a member.

  This positioning adjustment and holding member is composed of a positioning shaft 301 formed in the optical casing 231 and two mounting holes 302 and 303. That is, the positioning shaft 301 is positioned in the horizontal direction (more specifically, FIG. 1A) at the center in the width direction of the front end side surface (side surface facing the photosensitive drum 200) 232a of the outer peripheral surface 232 of the optical housing 231. ) Are provided so as to project in the direction of the center optical axis of the laser light indicated by the reference symbol A1 in FIG. It is provided in the form. That is, the mounting holes 302 and 303 are perpendicular to the left side surface (the lower side surface in FIG. 1A) 232b and the right side surface (the upper side surface in FIG. 1A) 232c (see FIG. 1 (A)). A mounting plate 311 fixed in a direction perpendicular to the paper surface in a) is formed so as to open in the horizontal direction. Here, the central optical axis A1 is an optical axis when the laser beam deflected and irradiated by the polygon mirror 220 is scanning the central portion in the width direction of the photosensitive drum 200. 1 is a light beam passage window formed on the distal side surface 232a of the outer peripheral surface 232 of the optical casing 231. The horizontal opening portion denoted by reference numeral 233 in FIG.

As described above, in this embodiment, the positioning shaft 301 is provided at the center of the irradiation direction A of the laser light irradiation surface A that is deflected and scanned by the polygon mirror 220, and the two mounting holes 302 and 303 have the positioning shaft 301. It is provided at each of the other two points of the triangle as the apex, and the attachment positions of the two attachment holes 302 and 33 are adjustable (adjustable) with the positioning shaft 301 as the center. Specifically, the entire optical casing 231 is provided so as to be rotatable (rotatable) about the positioning shaft 301, and the mounting holes 302 and 303 are optically arranged from the scanning surface side of the photosensitive drum 200. When the housing 231 is viewed in the horizontal direction (when viewed from the right side in FIG. 1 to the left), as shown in FIG. 2, it becomes an arcuate slot that draws a rotation locus centering on the positioning shaft 301. ing.

  Here, an example of a mounting structure between the positioning shaft 301 and the apparatus frame of the image forming apparatus and an example of a mounting structure between the mounting holes 302 and 303 and the apparatus frame of the image forming apparatus will be described with reference to FIG.

  FIG. 3A shows an example of a mounting structure between the positioning shaft 301 and the apparatus frame 390 of the image forming apparatus. That is, the distal end portion of the positioning shaft 301 is formed in a taper shape, and the device frame 390 that inserts and holds the distal end portion of the positioning shaft 301 is rotatably fitted to the distal end portion of the positioning shaft 301. A fitting hole 391 is formed. That is, the positioning shaft 301 is rotatable about the center axis of the fitting hole 391 by fitting the tip end portion of the positioning shaft 301 to the fitting hole 391 of the apparatus frame 390 in a rotatable manner.

  FIG. 3B shows an example of a mounting structure between the mounting holes 302 and 303 and the apparatus frame of the image forming apparatus. However, in FIG. 3B, the attachment structure of the mounting hole 303 formed on the right side surface 232c of the optical housing 231 and the apparatus frame is illustrated, but the structure is formed on the left side surface 232b of the optical housing 231. The mounting structure between the mounting hole 302 and the apparatus frame is the same. That is, the device frame 395 disposed in the vicinity of the side surface of the optical casing 231 is formed with a bolt screw rod 396 that protrudes in parallel with the central optical axis A1 of the laser irradiation surface A toward the photosensitive drum 200 side. The bolt screw rod 396 is fastened and fixed by a nut 398 while the mounting hole 303 of the mounting plate 311 fixed to the right side surface 232c of the optical housing 231 is inserted and supported.

  In the present embodiment, a plane B (see FIG. 1B) formed by the center of the positioning shaft 301 and the centers of the two mounting holes 302 and 303 is an irradiation surface A of the laser beam irradiated from the polygon mirror 220. Are arranged in parallel with each other. That is, when the centers of the two mounting holes 302 and 303 and the center of the positioning shaft 301 are projected onto a plane perpendicular to the central optical axis A1 of the laser irradiation surface A, the centers are positioned on a straight line (FIG. 1 ( b)). Thus, by providing so that it may be located on a straight line, the thickness of the optical housing | casing 231 can be made thin and the arrangement space of the optical scanning device 22 can be decreased.

  In this embodiment, as shown in FIGS. 1A and 1B, when the optical housing 231 is viewed in the horizontal direction from the scanning surface side of the photosensitive drum 200, the formation position of the positioning shaft 301 is Although the position is slightly shifted laterally from the central optical axis A1 of the laser irradiation surface A, this is on a line extending in parallel with the central optical axis A1 from the center of gravity with an emphasis on the weight balance of the entire optical casing 231. This is because the center of the positioning shaft 301 is disposed at the center. However, as shown in FIG. 4, when the optical housing 231 is viewed in the horizontal direction from the scanning surface side of the photosensitive drum 200, the position where the positioning shaft 301 is formed is directly below the central optical axis A1 of the laser irradiation surface A ( That is, the center of the positioning shaft 301 may be arranged on a vertical plane passing through the central optical axis A1.

Further, in the present embodiment, the positional relationship between the centers of two mounting holes 302 and 303 of the positioning shaft 301 is preferably a central isosceles triangle relationship that an apex of the positioning shaft 301. By adopting an isosceles triangle, the center of the positioning shaft 301 is obtained when the centers of the two mounting holes 302 and 303 and the center of the positioning shaft 301 are projected onto a plane perpendicular to the central optical axis A1 of the laser irradiation surface A. Since the distances T to the centers of the two mounting holes 302 and 303 are equal (T1 = T1), the rotational distances of the mounting holes 302 and 303 at the time of posture adjustment can be made equal.

  According to the optical scanning device 22 configured as described above, the positioning shaft 301 serving as a fulcrum for adjustment is provided at the center of the tip of the optical casing 231, and the position is adjusted to the other two points of the triangle with the positioning shaft 301 as a vertex. By providing the mounting holes 302 and 303 that can be adjusted, the posture adjustment of the optical scanning device 22 can be easily performed. That is, when the irradiation direction (scanning line) of the light beam onto the scanning surface of the photosensitive drum 200 that is the object to be scanned deviates from the reference scanning line L1 (for example, between the scanning line L2 and the reference scanning line L1 in FIG. 13). In the case of deviation as in the case of the relationship), the attachment positions of the attachment holes 302 and 303 may be shifted according to the deviation direction. That is, the direction in which the mounting holes 302 and 303 are shifted is a direction in which the light beam irradiation direction (scanning line) is rotated so as to coincide with the reference scanning line. Since it is sufficient to shift the mounting hole as if turning, it is possible to intuitively grasp the direction of shifting. This facilitates the posture adjustment of the optical scanning device.

  Here, another embodiment of the arrangement configuration of the positioning shaft 301 and the two attachment holes 302 and 303 will be described with reference to FIGS. However, FIGS. 5A to 9A are schematic views when the optical casing 231 is viewed in the horizontal direction from the scanning surface side of the photosensitive drum 200, and FIGS. 5B to 9B. These are explanatory drawings schematically showing the arrangement relationship between the positioning shaft 301 and the two attachment holes 302 and 303 corresponding to each arrangement configuration. However, FIG. 5 (b) to FIG. 9 (b) conceptually show the positional relationship between the positioning shaft 301 and the two mounting holes 302 and 303, and the actual positional relationship including the shape and distance is shown. It is not exactly shown.

<Other Example 1>
FIGS. 5A and 5B show an embodiment in which two mounting holes 302 and 303 are arranged on the lower side with respect to the positioning shaft 301. That is, when a straight line L5 is drawn parallel to the laser irradiation surface A through the center of the positioning shaft 301, the mounting holes 302 and 302 are disposed below the straight line L5, and from the center of the positioning shaft 301. In this embodiment, the horizontal distances to the mounting holes 302 and 303 are the same distance (T1).

<Other Example 2>
FIGS. 6A and 6B show an embodiment in which two attachment holes 302 and 303 are arranged on the upper side with respect to the positioning shaft 301. That is, when a straight line L5 is drawn parallel to the laser irradiation surface A through the center of the positioning shaft 301, the mounting holes 302 and 302 are arranged above the straight line L5, and In this embodiment, the horizontal distances to the mounting holes 302 and 303 are the same distance (T1).

<Other Example 3>
FIGS. 7A and 7B show an embodiment in which one mounting hole 302 is disposed on the upper side and the other mounting hole 303 is disposed on the lower side with respect to the positioning shaft 301. That is, when a straight line L5 is drawn parallel to the laser irradiation surface A through the center of the positioning shaft 301, one mounting hole 302 is disposed above the straight line L5, and the other mounting hole 303 is positioned above the straight line L5. Is also arranged on the lower side, and the horizontal distance from the center of the positioning shaft 301 to the mounting holes 302 and 303 is the same distance (T1). In addition, although illustration is abbreviate | omitted, the case where one attachment hole 302 is arrange | positioned below and the other attachment hole 303 is arrange | positioned above is also included in this Example 3.

<Other Example 4>
FIGS. 8A and 8B show an embodiment in which two mounting holes 302 and 303 are arranged on the upper side with respect to the positioning shaft 301. That is, when a straight line L5 is drawn parallel to the laser irradiation surface A through the center of the positioning shaft 301, the mounting holes 302 and 302 are arranged above the straight line L5, and In this embodiment, the horizontal distances to the mounting holes 302 and 303 are different distances (in this embodiment, T2 <T3, but T2> T3 is also included). Although not shown, when the straight line L5 is drawn parallel to the laser irradiation surface A through the center of the positioning shaft 301, the mounting holes 302 and 302 are disposed below the straight line L5. In addition, the fourth embodiment also includes a case where the horizontal distances from the center of the positioning shaft 301 to the mounting holes 302 and 303 are different distances.

<Other Example 5>
9A and 9B, when a straight line L5 is drawn parallel to the laser irradiation surface A through the center of the positioning shaft 301, one mounting hole 302 is disposed above the straight line L5, and the other The mounting holes 303 are arranged below the straight line L5, and the distances in the horizontal direction from the center of the positioning shaft 301 to the mounting holes 302 and 303 are different (in this embodiment, T2 <T3. However, this is an example in which T2> T3 is also included. Although not shown, when a straight line L5 is drawn parallel to the laser irradiation surface A through the center of the positioning shaft 301, one mounting hole 302 is disposed below the straight line L5, and the other This mounting hole 303 is also disposed above the straight line L5, and the horizontal distance from the center of the positioning shaft 301 to the mounting holes 302 and 303 is different. Included in Example 5.

  FIG. 10 is a device for facilitating the adjustment of the attitude of the optical housing 231, and a triangular protrusion or a triangular notch is formed on the lateral edge of the mounting plate 311 in which the mounting hole 303 (302) is formed. A mark 312 made of (a triangular protrusion in FIG. 10) is provided, and a scale 397 is provided on the device frame 395 facing the mark 397 by stamping or printing or sticking a scale seal. However, a mark may be provided on the apparatus frame 395 side and a scale may be provided on the mounting plate 311 side. By attaching the scale in this way, it is possible to read from the mark 312 and the scale 397 how much to adjust when adjusting the attitude of the optical casing 231. Therefore, the attitude can be easily adjusted. It becomes possible. In FIG. 10, a mark is provided on the mounting plate 311 and a scale is provided on the device frame 395. However, a scale may be provided on the mounting plate 311 and a mark may be provided on the device frame 395.

(A) is a schematic plan view showing the arrangement of main optical components and the optical path of a light beam of an optical scanning device according to an embodiment of the present invention, and (b) is an optical scanning device according to an embodiment of the present invention. A side view seen from the photosensitive drum side, (c) is a schematic sectional view of the optical scanning device as seen from the side. It is explanatory drawing which showed typically the arrangement | positioning relationship between a positioning shaft and two attachment holes. (A) is a partially enlarged sectional view showing an example of an attachment structure between the positioning shaft and the apparatus frame of the image forming apparatus, and (b) shows an example of an attachment structure between the attachment hole and the apparatus frame of the image forming apparatus. It is a partially expanded sectional view. (A) is a schematic plan view showing an arrangement of main optical components and an optical path of a light beam of an optical scanning device according to another embodiment of the present invention, and (b) is an optical scanning according to another embodiment of the present invention. The side view which looked at the apparatus from the photoconductive drum side, (c) is the schematic sectional view which looked at the optical scanning device from the side. (A) is the schematic which shows the other Example 1 of the arrangement | positioning relationship between the positioning axis | shaft and two attachment holes at the time of seeing an optical housing | casing in the horizontal direction from the scanning surface side of a photosensitive drum, (b). FIG. 5 is an explanatory view schematically showing the arrangement relationship between a positioning shaft and two attachment holes corresponding to the arrangement configuration. (A) is the schematic which shows the other Example 2 of the arrangement | positioning relationship between the positioning axis | shaft and two attachment holes at the time of seeing an optical housing | casing in the horizontal direction from the scanning surface side of a photosensitive drum, (b). FIG. 5 is an explanatory view schematically showing the arrangement relationship between a positioning shaft and two attachment holes corresponding to the arrangement configuration. (A) is the schematic which shows other Example 3 of the arrangement | positioning relationship between the positioning axis | shaft and two attachment holes at the time of seeing an optical housing | casing in the horizontal direction from the scanning surface side of a photosensitive drum, (b). FIG. 5 is an explanatory view schematically showing the arrangement relationship between a positioning shaft and two attachment holes corresponding to the arrangement configuration. (A) is the schematic which shows the other Example 4 of the arrangement | positioning relationship between the positioning axis | shaft and two attachment holes at the time of seeing an optical housing | casing in the horizontal direction from the scanning surface side of a photosensitive drum, (b). FIG. 5 is an explanatory view schematically showing the arrangement relationship between a positioning shaft and two attachment holes corresponding to the arrangement configuration. (A) is the schematic which shows the other Example 5 of the arrangement | positioning relationship between the positioning axis | shaft and two attachment holes at the time of seeing an optical housing | casing in the horizontal direction from the scanning surface side of a photosensitive drum, (b). FIG. 5 is an explanatory view schematically showing the arrangement relationship between a positioning shaft and two attachment holes corresponding to the arrangement configuration. It is explanatory drawing which shows the example which provided the mark and the scale on the attachment board in which the attachment hole is formed, and the apparatus frame facing this. 1 is a cross-sectional view illustrating an overall configuration of an image forming apparatus including an optical scanning device according to the present invention. FIG. 4 is a cross-sectional view showing details around a photosensitive drum. It is a top view which shows arrangement | positioning of the main optical components of the conventional optical scanning apparatus, and the optical path of a light beam. It is a schematic sectional drawing which shows arrangement | positioning of the main optical components of the conventional optical scanning apparatus, and the optical path of a light beam. It is explanatory drawing which shows the correspondence of the rocking | fluctuation fulcrum and adjustment point in the conventional optical scanning device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Printer 3 Scanner 4 Automatic document conveying apparatus 5 Sheet post-processing apparatus 6 Multi-stage paper feeding unit 7 System rack 8 Relay conveyance unit 9 Paper discharge tray 20 Electrophotographic process section 21 Paper supply section 22 Optical scanning apparatus 26 Power supply unit 200 Photosensitive drum 220 Polygon mirror 221 Semiconductor laser 222 Concave lens / collimator lens 223a, 223b fθ lens 226 Aperture plate 227 Cylindrical lens 231 Housing 232 Outer peripheral surface 232a Front side surface 232b Left side surface 232c Right side surface 301 Positioning shafts 302, 303 Mounting Hole 311 Mounting plate 312 Mark 390 Device frame 391 Fitting hole 395 Device frame 396 Bolt screw rod 397 Scale 398 Nut

Claims (8)

A light source for irradiating laser light, a rotating polygon mirror for deflecting and scanning the laser light from the light source, and an imaging lens for forming an image of the laser light deflected by the rotating polygon mirror and irradiating the scanning surface of the scanned object An image forming apparatus including an optical scanning device provided in an optical housing,
The optical casing is formed with one positioning shaft that is rotatably attached to the image forming apparatus main body and two attachment holes that are attached to the image forming apparatus main body so as to be adjustable in position. provided in the irradiation direction central portion of the irradiation surface of said rotary polygonal mirror in a deflection scanning laser light, said two attachment holes, that provided on each of the other two points the position of a triangle whose vertices are the positioning shaft And formed in a long hole having a shape that draws a rotation locus around the positioning axis,
By adjusting the mounting position of the two mounting holes with respect to the image forming apparatus main body and rotating the optical casing around the positioning axis, the optical with respect to the scanned object attached to the image forming apparatus main body is obtained. An image forming apparatus characterized in that a posture of a housing is adjustable. The image forming apparatus according to claim 1.
An image forming apparatus, wherein a line connecting the centers of the two mounting holes is parallel to an irradiation surface of the laser beam. The image forming apparatus according to claim 1, wherein:
2. An image forming apparatus according to claim 1, wherein the positional relationship between the center of the positioning shaft and the centers of the two mounting holes is an isosceles triangle having the center of the positioning shaft as a vertex. The image forming apparatus according to any one of claims 1 to 3, wherein:
When the centers of the two mounting holes and the center of the positioning shaft are projected in a direction perpendicular to the irradiation direction of the laser beam, the centers are positioned on a straight line. Image forming apparatus. The image forming apparatus according to any one of claims 1 to 4, wherein:
An image forming apparatus, wherein the center of the positioning axis is positioned on a vertical plane passing through the optical axis center of the laser light irradiation surface. The image forming apparatus according to any one of claims 1 to 5 , wherein:
Before Symbol positioning shaft is provided on the imaging lens side of the optical housing, an image forming apparatus, characterized in that the mounting hole is provided on the rotary polygonal mirror side of the optical housing. The image forming apparatus according to any one of claims 1 to 6, wherein:
An image forming apparatus, wherein the laser beam deflected by the rotary polygon mirror is irradiated to a scanned body without being reflected after passing through the imaging lens. The image forming apparatus according to any one of claims 1 to 7,
Either one of a mark or a scale indicating a position adjustment amount is provided on the attachment portion of the optical housing in which the attachment hole is formed, and the mark or the position adjustment amount is provided on the image forming apparatus main body facing the attachment portion. An image forming apparatus, wherein the other of the scales shown is provided.

Images