JP5821195B2 - Adjusting and fixing structure of light emitting element, optical scanning device, and image forming apparatus - Google Patents

Description

  The present invention relates to an optical scanning device used in a writing optical system of an image forming apparatus such as a digital copying machine or a laser printer, and more particularly to a position adjustment and fixing technique of a light emitting element having a plurality of light beams.

  Conventionally, an image forming apparatus using a laser as a light source in electrophotographic image forming is widely known, and a light emitting element is pressed against an optical housing as a technique for adjusting a pitch of a beam irradiated from a plurality of laser diodes. For example, “Patent Document 1” discloses a technique for adjusting and fixing the beam pitch by rotating the beam pitch.

  Further, as a technique for preventing the laser diode from coming off, there is a technique in which a claw is provided in the vicinity of the laser diode mounting hole entrance and the laser diode flange is fixed by the claw when the laser diode is inserted into the mounting hole. 2 ”. In this technique, there is no distortion due to press-fitting, and no separate member is required, so the cost can be reduced.

  In the technique disclosed in “Patent Document 1”, as shown in FIG. 13, as indicated by a broken line in FIG. 13 due to the action of the pressing force A of the rotating jig that holds the light emitting element 9 even if the beam pitch is adjusted. In addition, there is a problem that the side wall 7a of the optical housing 7 falls inward and the beam interval cannot be adjusted accurately (reference numeral 7b indicates a reference surface when the light emitting element 9 is attached). In recent years, optical housings that are relatively easy to deform made of resin are often used for cost reduction and weight reduction in recent years.When the pressing force of the rotating jig is released after adjustment, the optical housing is restored to its original shape. The optical axis and beam pitch change as compared with the adjustment.

  Further, in the technique disclosed in “Patent Document 2”, the fixing claw is disposed toward the inner side than the flange portion of the laser diode. Therefore, in either case of inserting or removing the laser diode. Also, there is a risk that the nail will be overloaded and damaged.

  The present invention solves the above-mentioned problems, simplifies the jig configuration, prevents changes in the optical axis and beam pitch of the light emitting element during adjustment and fixing, and allows the light emitting element to be adjusted for rotational adjustment. It is an object to provide an adjustment fixing structure of a light emitting element that can be held.

According to a first aspect of the present invention, the distance between each light emitting point is adjusted by rotating a light emitting element having a flange portion and a plurality of light emitting points around the optical axis of the light emitting point, so that the light emitting element is installed in the housing. In the adjustment fixing structure of the light emitting element to be fixed,
The housing has a mounting hole having a reference surface to which the light emitting element is attached, the mounting hole has a holding portion that rotatably holds the flange portion in contact with the reference surface, and the light emitting element has the The flange portion has a notch portion that avoids interference with the holding portion when attached to the housing.

According to a second aspect of the invention, the adjustment fixing structure of a light emitting device according to claim 1, further wherein the light emitting element is characterized in Tei Rukoto secured to the housing by adhesives.

According to a third aspect of the invention, the adjustment fixing structure of a light emitting device according to claim 1, further wherein the light emitting element is characterized in Tei Rukoto secured to the housing by fixed members.

According to a fourth aspect of the present invention, there is provided an optical scanning device having the light emitting element adjusting and fixing structure according to any one of the first to third aspects .

A fifth aspect of the present invention is an image forming apparatus having the optical scanning device according to the fourth aspect.

  According to the present invention, there is no need to press the light emitting element or the rotating jig itself that holds the light emitting element by the rotating jig against the housing, and the housing is not elastically deformed because it does not receive unnecessary external force. It is possible to prevent the occurrence of a problem that affects the adjustment of the beam interval.

1 is a schematic front view of an image forming apparatus to which an embodiment of the present invention can be applied. It is the schematic explaining the optical scanning device used for one Embodiment of this invention. It is a schematic block diagram of the optical scanning device used for one Embodiment of this invention. It is the schematic explaining the adjustment fixing structure of the light emitting element used for one Embodiment of this invention. It is the schematic explaining adjustment of the light emitting element in one Embodiment of this invention. It is a flowchart explaining the adjustment fixation procedure of the light emitting element in one Embodiment of this invention. It is the schematic which shows the attachment state of the light emitting element used for one Embodiment of this invention. It is the schematic which shows the attachment state of the light emitting element used for one Embodiment of this invention. It is the schematic which shows the fixed state of the light emitting element used for one Embodiment of this invention. It is the schematic which shows the fixed state of the light emitting element used for one Embodiment of this invention. It is the schematic explaining attachment of the light emitting element used for the modification of one Embodiment of this invention. It is the schematic explaining attachment of the light emitting element used for the other modification of one Embodiment of this invention. It is the schematic which shows the problem of a prior art.

  FIG. 1 shows an image forming apparatus employing one embodiment of the present invention. In the figure, an image forming apparatus 500 includes an optical scanning device 100, four photosensitive drums 30A, 30B, 30C, and 30D, an intermediate transfer belt 40, a paper feed tray 60, a paper feed roller 54, registration roller pairs 52 and 56, The image forming apparatus includes a fixing unit 50, a paper discharge roller pair 58, a control unit (not shown), an apparatus main body 501, and the like. On the upper surface of the apparatus main body 501, a paper discharge tray 501a for discharging printed paper is provided, and the optical scanning device 100 is disposed below the paper discharge tray 501a. Based on image information sent from an image reading device (not shown) or an external device, the optical scanning device 100 emits a black image component laser beam to the photosensitive drum 30A, and a cyan image component laser to the photosensitive drum 30B. The light is scanned with the laser light of the magenta image component on the photosensitive drum 30C, and the laser light of the yellow image component is scanned on the photosensitive drum 30D.

  The photosensitive drums 30A, 30B, 30C, and 30D are juxtaposed below the optical scanning device 100, and are each driven to rotate clockwise in FIG. 1 by driving means (not shown). Around the photosensitive drum 30A, a charging unit 32A for charging the surface of the photosensitive drum 30A with a predetermined voltage, a developing unit 33A having a cartridge filled with black component toner, a developing roller, and the like, and the photosensitive drum 30A A cleaning unit 31A that has a cleaning blade in contact with the surface and cleans the surface of the photosensitive drum 30A is disposed. A similar configuration is also arranged around the other photosensitive drums 30B, 30C, and 30D except for the color of the toner stored in the developing means, and cyan toner is supplied to the developing means 33C in the developing means 33B. Is a magenta component toner, and the developing means 33D stores a yellow component toner.

  The endless belt-shaped intermediate transfer belt 40 is stretched around driven rollers 40a and 40c and a driving roller 40b, and the upper surface thereof is disposed so as to be in contact with each of the photosensitive drums 30A, 30B, 30C and 30D. When 40b is driven to rotate, it is driven to travel in the direction of the arrow in FIG. At a position facing the driven roller 40c via the intermediate transfer belt 40, there is a transfer charger 48 as a transfer means for applying a voltage having a polarity opposite to that of the charging means 32A, 32B, 32C, 32D to the intermediate transfer belt 40. The intermediate transfer belt 40 is disposed close to the intermediate transfer belt 40 at a predetermined distance.

  A sheet feeding tray 60 for storing a plurality of sheets 61 is disposed below the intermediate transfer belt 40, and a sheet feeding unit for separating and feeding the sheets 61 one by one at the upper right side of the sheet feeding tray in FIG. A roller 54 is provided. The sheet 61 fed from the sheet feed tray 60 by the sheet feed roller 54 is fed toward the gap between the transfer belt 40 and the transfer charger 48 via the registration roller pair 56.

  A fixing unit 50 comprising a roller pair of a pressure roller and a heating roller is disposed on the downstream side in the sheet conveyance direction of the proximity portion between the transfer belt 40 and the transfer charger 48. The fixing means 50 fixes the toner image transferred onto the paper 61 by heat and pressure, and the fixed paper 61 is sent to a paper discharge roller pair 58 comprising a pair of rollers via a registration roller pair 52. The paper is sequentially discharged onto the paper discharge tray 501a.

  As shown in FIG. 2, the optical scanning device 100 generates two laser beams P1 and P2 which are a plurality of light emitting points from the light emitting element 9, and parallelizes the beams P1 and P2 by the collimator lens 10, respectively. Then, the light is irradiated onto the reflecting surface 13a of the polygon mirror 13 serving as scanning means via the diaphragm 11 and the cylindrical lens 12, and is imaged on the photosensitive drum 30 via the fθ lens 14. The beams P1 and P2 enter the reflecting surface 13a while being separated in the Z-axis direction, which is the axial direction of the polygon mirror 13, and are scanned in the Y-axis direction, which is the main scanning direction, respectively. An electrostatic latent image is formed on the surface of the photosensitive drum 30 in accordance with the main scanning in the direction and the sub-scanning in the Z-axis direction by the rotation of the photosensitive drum 30.

  The cylindrical lens 12 condenses the beams P1 and P2 linearly with respect to the reflection surface 13a, and prevents the point image formed on the photosensitive drum 30 from being distorted due to the surface tilt of the polygon mirror 13. It has a function. The fθ lens 14 has a function of preventing the distortion of the point image on the photosensitive drum 30 like the cylindrical lens 12 and corrects the point image to be scanned on the photosensitive drum 30 at a constant speed in the main scanning direction. It has a function to do.

  Each beam P1, P2 is separated below the main scanning plane by the detection mirror 16 at the end in the Y-axis direction on the main scanning plane (XY plane) and guided to the optical sensor 17, and writing is started by a controller (not shown). After being converted into a signal, it is transmitted to the light emitting element 9. The light emitting element 9 receives the writing start signal and starts writing modulation of the beams P1 and P2. In this way, the writing start (writing) position of the electrostatic latent image formed on the photosensitive drum 30 is controlled by adjusting the timing of writing modulation of the beams P1 and P2.

  The cylindrical lens 12, the polygon mirror 13, the fθ lens 14, and the like are attached to the bottom wall of the optical housing 7 shown in FIG. 3 attached to the apparatus main body 501, and the light emitting element 9 is attached to the side wall 7 a of the optical housing 7. After each optical component is attached to the optical housing 7, the upper opening of the optical housing 7 is closed by a lid member (not shown). The attachment of the light emitting element 9 to the side wall 7a will be described later.

The operation of the image forming apparatus 500 including the optical scanning device 100 described above will be described below.
When image information is sent from an external device or the like, the laser beams P1 and P2 emitted from the light emitting element 9 are condensed on the reflecting surface 13a of the polygon mirror 13 by the collimator lens 10, the diaphragm 11, and the cylindrical lens 12. The laser beams P1 and P2 deflected by the polygon mirror 13 are condensed on the surface of the photosensitive drum 30A through the fθ lens 14. Similarly, laser beams emitted from other light emitting elements (not shown) are respectively deflected by polygon mirrors and condensed on the surfaces of the other photosensitive drums 30B, 30C, and 30D. At this time, the laser beam from the optical scanning device 100 is incident on the writing area of each of the photosensitive drums 30A to 30D in a state adjusted to a preset intensity.

  The photosensitive layers provided on the respective surfaces of the photosensitive drums 30A, 30B, 30C, and 30D are charged with a predetermined voltage by the charging means 32A, 32B, 32C, and 32D, so that charges are distributed at a constant density. ing. When each of the photoconductive drums 30A, 30B, 30C, and 30D is scanned as described above, the photosensitive layer at the portion where the laser beam is condensed has conductivity, and the potential is almost zero in that portion. It becomes. Thus, when the surface of each of the photoconductive drums 30A, 30B, 30C, and 30D is scanned by the laser beam while rotating in the direction indicated by the arrow in FIG. 1, the surface of each of the photoconductive drums 30A, 30B, 30C, and 30D Each is formed with an electrostatic latent image.

  When electrostatic latent images are formed on the surfaces of the photosensitive drums 30A, 30B, 30C, and 30D, the photosensitive drums 30A, 30B, 30C, and 30D are developed by the developing rollers of the developing units 33A, 33B, 33C, and 33D. Toner is supplied to the surface of 30D. The supplied toner is electrostatically attached to the electrostatic latent images on the photosensitive drums 30A, 30B, 30C, and 30D, and each electrostatic latent image is visualized by each color toner. Each visualized toner image is superimposed and transferred onto the surface of the intermediate transfer belt 40, and a full-color toner image is formed on the intermediate transfer belt 40. The formed full-color toner image is collectively transferred to the surface of the paper 61 fed from the paper feed tray 60 by the operation of the transfer charger 48, and the paper 61 on which the image is transferred is sent to the fixing means 50 and transferred. After the image is fixed, the paper is discharged onto the paper discharge tray 501a by the paper discharge roller pair 58.

  Here, the mounting structure of the light emitting element 9 which is a characteristic part of the present invention will be described. As shown in FIG. 4, a mounting hole 7c for attaching the light emitting element 9 to the side wall 7a, a reference for positioning the light emitting element 9 in the optical axis direction when the light emitting element 9 is integrally formed with the mounting hole 7c. A holding portion 21a formed integrally with the surface 7b and the mounting hole 7c is provided. As shown in FIG. 5, the light emitting element 9 has a flange portion 9a and a laser array for generating the laser beams P1 and P2. 9b are integrally provided. The holding portion 21a is formed at two locations so as to protrude toward the inner diameter side of the mounting hole 7c, and is provided so that a space is generated between the reference surface 7b side surface and the reference surface 7b. The outer diameter of the flange portion 9a is formed such that the light emitting element 9 can rotate when inserted into the mounting hole 7c, and the thickness of the flange portion 9a is between the holding portion 21a and the reference surface 7b. It is formed so as to be slightly smaller than the thickness of the space, and the light emitting element 9 is formed to have a thickness that can rotate smoothly in the space. The flange 9a is provided with a notch 9c at a position corresponding to each holding portion 21a for avoiding interference with each holding portion 21a when the light emitting element 9 is inserted into the mounting hole 7c. In the present embodiment, the cutout portion 9c has a rectangular configuration provided at two locations facing each other. However, the location, the number, and the shape are not limited thereto, and one or a plurality of the cutout portions 9c may be provided anywhere on the outer periphery of the flange portion 9a. Any configuration may be used as long as it corresponds to the shape and location of each holding portion 21a, such as an arc shape or a wedge shape.

  Next, a procedure for adjusting the attachment of the light emitting element 9 to the side wall 7a will be described with reference to FIG. First, the notch portion 9c of the light emitting element 9 is aligned with the holding portion 21a, and the light emitting element 9 is inserted into the mounting hole 7c as shown in FIG. 7A (ST1), and the bottom surface of the flange portion 9a as shown in FIG. Is abutted against the reference surface 7b (ST2). Next, the light emitting element 9 is chucked by a rotation jig (not shown), and rotation adjustment is performed to rotate the light emitting element 9 about the optical axis (ST3). At this time, the arrangement direction of the laser array 9b is adjusted by rotating the light emitting element 9 in the direction indicated by the arrow R in FIG. 5, and the beam interval ΔP between the two laser beams P1 and P2 is designed on the photosensitive drum 30. The beam spacing is adjusted to match the value. When the rotation of the light emitting element 9 is adjusted, the light emitting element 9 can be rotatably held in a state where the bottom surface is in contact with the reference surface 7b by each holding portion 21a (ST4). As a result, it is not necessary to press the light emitting element 9 or the rotating jig itself against the side wall 7a by a rotating jig as in the prior art, and the side wall 7a is not subjected to unnecessary external force, so that it is not elastically deformed, and the side wall 7a is elastically deformed. It is possible to prevent the occurrence of a problem that affects the adjustment of the beam interval. After adjusting each beam interval, as shown in FIG. 9, each notch 9c is filled with an adhesive to fix the light emitting element 9 to the side wall 7a (ST5). Regarding the fixing of the light emitting element 9, instead of fixing with the above-described adhesive, a fixing member 34 for fixing the light emitting element 9 is prepared as shown in FIG. 10, and the fixing member 34 is fixed to the side wall 7a with a screw 35. It is good also as a structure which fixes the light emitting element 9 by.

  With the above-described configuration, it is possible to prevent the position of the scanning light beam from changing due to the tilt of the side wall of the optical housing. Therefore, if the optical writing system is used, the stability of the scanning line can be obtained, so that a good image quality can be obtained. . In addition, since the function of the jig for holding the light emitting element can be limited to only rotation adjustment, the structure of the jig can be simplified and the cost can be reduced. In addition, the cost of parts can be reduced by bonding and fixing the light emitting elements, and the layout around the light emitting elements can be improved because the number of parts is small, and the writing apparatus can be downsized. In addition, since the light emitting element can be fixed with a fixing member and screw with a simple shape, the cost of components can be reduced, and the simple configuration can improve the accuracy of the components and shorten the adjustment time. Equipment can be provided.

  FIG. 11 shows a modification of the above embodiment of the present invention. In this modified example, instead of the flange portion 9a of the light emitting element 9, a circular flange portion 9d obtained by scraping two opposing portions in a straight line is used, and instead of the mounting hole 7c formed in the side wall 7a, light emission is performed. The shape on the side where the element 9 is inserted is similar to the flange portion 9d and is formed to be slightly larger and has a reference surface 7b inside, and the flange portion between the reference surface 7b and the surface where the light emitting element 9 is inserted. This is different from the above-described embodiment in that a mounting hole 7d having a circular space having a thickness slightly larger than 9d is used. According to this modification, the light emitting element 9 is inserted into the mounting hole 7d in such a manner that the flange portion 9d matches the mounting hole 7d, and the light emitting element 9 is rotated with the bottom surface of the flange portion 9d abutting against the reference surface 7b. By doing so, the surface of the side wall 7a on the side where the light emitting element 9 is inserted functions as the holding portion 21b, and the same effect as the above embodiment can be obtained.

  FIG. 12 shows another modification of the above embodiment. In this example, a circular attachment hole 7e having a reference surface 7b having a depth slightly larger than the thickness of the flange portion 9d is provided in the side wall 7a, and the flange portion 9d is provided on the surface of the side wall 7a on the side where the light emitting element 9 is attached. A holding member 41 having a groove portion formed slightly larger than the interval between the scraping portions is fixed by a screw 42. According to this example, the light emitting element 9 is inserted into the mounting hole 7e so that the flange portion 9d matches the groove portion, and the light emitting element 9 is rotated with the bottom surface of the flange portion 9d abutting against the reference surface 7b. The portion of the holding member 41 that forms the groove functions as the holding portion 41a, and the same effects as those of the above embodiment can be obtained. In this configuration, the number of parts increases, but the mounting hole 7e can be easily processed.

  In the above embodiment and each modification, since the thickness of the holding portions 21a, 21b, 41a can be freely set within the thickness of the side wall 7a, the protruding amount of the pin of the light emitting element 9 can be determined by the thickness of the holding portion. The jig can be easily attached. Further, when the light emitting element 9 is attached to the LD board, the pin length of the light emitting element 9 can be secured, and the attachment becomes easy. In the embodiment and each modification, the number of laser beams is 2, but may be 3 or more.

7 Housing (Optical housing)
7b Reference surface 7c, 7d, 7e Mounting hole 9 Light emitting element 9a, 9d Flange 9c Notch 21a, 21b Holding part 34 Fixing member 41a Holding part 100 Optical scanning device 500 Image forming apparatus P1, P2 Light emitting point (laser beam)

JP 2001-296490 A JP 2007-50540 A

Claims (5)

A light emitting element adjusting and fixing structure for fixing a light emitting element to a housing by adjusting a distance between the light emitting points by rotating a light emitting element having a flange portion and a plurality of light emitting points around an optical axis of the light emitting point. In
The housing has a mounting hole having a reference surface to which the light emitting element is attached, and the mounting hole has a holding portion that rotatably holds the flange portion in contact with the reference surface,
The light emitting element adjustment fixing structure, wherein the light emitting element has a notch portion in the flange portion for avoiding interference with the holding portion when the light emitting element is attached to the housing. In the adjustment fixing structure of the light emitting element according to claim 1,
The light emitting device, adjusting the fixed structure of the light emitting element characterized Tei Rukoto secured to the housing by adhesives. In the adjustment fixing structure of the light emitting element according to claim 1,
The light emitting device, adjusting the fixed structure of the light emitting element characterized Tei Rukoto secured to the housing by fixed members.   An optical scanning device comprising the light-emitting element adjustment fixing structure according to claim 1.   An image forming apparatus comprising the optical scanning device according to claim 4.

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