JP2010066431A - Optical scanner and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control the repulsive force of a seal member without modifying the shapes of a housing and a cover member to enhance the airtightness of the whole optical scanner without causing local deformations of the housing and the cover member. <P>SOLUTION: The optical scanner includes: an optical housing 10 which houses an optical system; a single or a plurality of cover members 11; and the seal member 17a which is disposed in the gap between the optical housing 10 and the cover member 11 to keep the airtightness, wherein the seal member 17a is disposed at the whole circumference of the cover member 11, and a variant shape part 18 of which the thickness dimension d1 is smaller than the thickness dimension d2 of other parts of the seal member is formed at least one part of the seal member 17 located at the substantially central position 35 of fastening positions 24, 25 at which the cover member 11 is fastened on the optical housing 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical operation device and an image forming apparatus, and in particular, a light source, a scanning unit that irradiates a light irradiation target with light from the light source and scans the light irradiation target, and an optical path from the light source to the light irradiation target. An optical element, a housing that houses the optical element, one or more cover members for covering the housing, and a seal member that is disposed in a gap between the cover member and the housing to ensure the sealing performance of the entire apparatus. The present invention relates to an optical scanning device and an image forming apparatus including the optical scanning device.

  An image forming apparatus such as a laser printer, a digital copying machine, or a laser fax machine has a polygon mirror formed in a regular polygon that deflects and scans a light beam from a light source, and the light beam scanned by the polygon mirror is placed on a photosensitive surface. In addition to an optical element (scanning lens) for forming an image, an optical scanning device provided with a photodetector on the scanning start side outside the effective exposure region is mounted in order to determine the writing start position. .

  The optical scanning device irradiates light to a photoconductor using an optical element such as a lens or a mirror. When a minute foreign matter such as dust adheres to the optical element, a scanning line formed on the surface of the photoconductor is formed. It will be affected, and abnormal images such as white lines and missing images will occur. For this reason, the optical scanning apparatus often takes a sealed structure by providing a cover member on a housing in which each optical element is mounted.

  On the other hand, since the polygon mirror deflects the beam from the light source and rotates at high speed, the change in the airflow in the vicinity of the polygon mirror is large, especially the centrifugal force causes the air pressure to drop at the center of the polygon, and the surrounding air is sucked in. It becomes.

  For this reason, even the staying thing in the air is sucked, and the reflective surface of the polygon mirror may become cloudy after a long operation. Therefore, there is a method of providing a space for storing the polygon mirror separately in the housing and sealing it there. However, an optical scanning apparatus that employs the counter scanning method often has a configuration in which the optical path and arrangement of optical elements are very complicated, and in some cases, a space for storing polygons cannot be secured.

  Normally, the housing is sealed by using a cover member and screws to make a sealed structure, but there is a minute gap between the cover member and the housing. For this reason, foreign matter having a certain size such as dust can be prevented from entering the apparatus by sealing with a cover member. However, for very small stays of 1 μm or less, for example, there is a relation of polygonal airflow and the cover member It will be sucked from the gap. Although this stagnant material does not adhere to an optical element such as a lens / mirror and lead to an abnormal image, it may adhere to the polygon mirror surface and become cloudy when its density increases.

  Therefore, in order to fill a minute gap between the mating surfaces of the housing and the cover member, a structure may be employed in which a sponge seal is arranged around the entire cover member to improve the sealing performance of the entire optical scanning device. In this structure, by adjusting the thickness of the seal, the amount of crushing when the cover member and the housing are screwed can be changed, and the sealing performance can be controlled by a certain amount. However, since the cover is crushed between the cover member and the cover member, a repulsive force generated when the seal is crushed acts on the cover member and the housing. Therefore, there is a risk of deforming the housing and the cover member. When the cover member and the housing are fastened by the screw member, the deformation due to the repulsive force is determined by the fastening position of the screw member, the rigidity of the housing and the cover member, and the outer shape of the housing, so that the deformation of the housing becomes complicated.

  Moreover, the housing of the optical element has a complicated shape due to its function, such as the arrangement of the optical element, the securing of the optical path, and the rib for strength improvement. May deform and affect its optical characteristics.

  In Patent Document 1, a light beam emitted from a light source device is incident on a deflecting reflection surface of a rotary polygon mirror and deflected, and then the deflected light beam is passed through two fθ lenses, a folding mirror, and a BLT lens. A light beam scanning apparatus that condenses light spots on the light source, accommodates the light source device, the rotary polygon mirror, and the fθ lens in the housing, and the opening of the housing is closed by a cover member. A device is described in which a partition wall is provided so that the device, the rotary polygon mirror, and the fθ lens are hermetically stored in independent spaces.

  Patent Document 2 discloses an optical scanning device including a polygon scanner having a rotating polygon mirror that deflects laser light emitted from a light source, and an optical housing that supports the polygon scanner. A side wall provided in an optical housing so as to surround and a transmission type optical element that constitutes a part of the side wall and transmits laser light deflected by a rotary polygon mirror to the outside of the side wall is described. ing.

Further, Patent Document 3 discloses a polygon scanner having a rotating polygon mirror that deflects laser light emitted from a light source, an optical housing that supports the polygon scanner, and an optical housing that surrounds the polygon scanner. Side wall, a transmissive optical element that constitutes a part of the side wall and transmits laser light deflected by the rotary polygon mirror to the outside of the side wall, and is fixed to the upper edge of the side wall to close the space in the side wall. An optical scanning device comprising: a plate-like cover member, and an elastic seal member that is interposed between the upper edge of the side wall and the plate-like cover member and seals the gap. What provided the hole for exposing a part of member is described.
JP 2006-078903 A Japanese Patent Laid-Open No. 2004-192010 JP 2000-098287 A

  However, those described in Patent Document 1 and Patent Document 2 are designed to confine and take measures against heat and noise generated from the polygon mirror by making the periphery of the polygon motor a sealed structure. In other words, the sealing property is not secured against very small foreign matter.

  In addition, the one described in Patent Document 3 uses a seal member between the cover member and the housing to improve the sealing performance. However, the seal member is provided as a countermeasure against heat and noise of the polygon motor. It does not apply when the space for storing cannot be provided separately in the housing.

  Therefore, the present invention controls the repulsive force of the seal member without changing the shape of the housing or cover member, and improves the sealing performance of the entire optical scanning apparatus without causing local deformation of the housing or cover member. An object of the present invention is to provide an optical scanning device that can be used, and an image forming apparatus equipped with the optical scanning device.

  According to a first aspect of the present invention, there is provided a light source, a scanning unit that irradiates the light irradiation target with light from the light source and scans the light, an optical element provided on an optical path from the light source to the light irradiation target, and the scanning. A housing for housing the optical system including the means and the optical element, one or a plurality of cover members for covering the housing, and a seal member that is disposed in a gap between the housing and the cover member to ensure hermeticity. In the optical scanning device, the seal member is arranged on the entire circumference of the cover member, and the thickness dimension is set at least at one position of the seal member located at the approximate center of the fastening position where each cover member is fastened to the housing. It is an optical scanning device characterized in that a deformed portion different from other portions of the seal member is formed.

  According to a second aspect of the present invention, in the optical scanning device according to the first aspect, the thickness of the deformed portion is smaller than the thickness of the other portion of the seal member.

  According to a third aspect of the present invention, in the optical scanning device according to the first aspect, a thickness dimension of the deformed portion is larger than a thickness dimension of other portions of the seal member.

  According to a fourth aspect of the present invention, there is provided a light source, a scanning unit that irradiates the light irradiation target with light from the light source and scans it, an optical element provided on an optical path from the light source to the light irradiation target, and the scanning. And an optical system including the optical element, an upper cover member covering the upper side of the housing, a lower cover member covering the lower side of the housing, and a gap between the upper cover member and the lower cover member and the housing The seal member is disposed on the entire periphery of the upper cover member and the lower cover member, and is perpendicular to the fastening direction of the cover member and the housing. When the seal position of the upper cover member and the seal position of the lower cover member on the plane are shifted in the radial direction from the center of the housing, the seal member is disposed at the location. Optical scanning device characterized by the thickness dimension to form a different profile portion and other portions of the sealing member.

  According to a fifth aspect of the present invention, in the optical scanning device according to the fourth aspect, the sealing position of the upper cover member and the sealing position of the lower cover member in a plane perpendicular to the fastening direction of each cover member and the housing are from the center of the housing. When shifted in the radial direction, a deformed portion whose thickness dimension is smaller than the thickness dimension of the other part is formed on the seal member having a longer distance from the center of the housing out of the two seal members, or The seal member on the short distance side is formed with a deformed portion whose thickness dimension is larger than that of other portions, or a deformed portion is formed on each seal member.

  According to a sixth aspect of the present invention, there is provided a light source, a scanning unit that irradiates a light irradiation target with light from the light source and scans the light, an optical element provided on an optical path from the light source to the light irradiation target, and the scanning. And an optical system including the optical element, an upper cover member covering the upper side of the housing, a lower cover member covering the lower side of the housing, and a gap between the upper cover member and the lower cover member and the housing And a sealing member that secures hermeticity. The sealing member is disposed on the entire periphery of the upper cover member and the lower cover member, and is a plane perpendicular to the fastening direction of the cover member and the housing. When the seal position of the upper cover member and the seal position of the lower cover member are shifted radially from the center of the housing, the upper cover Gap size between the member or the lower cover member and the housing is a light scanning device characterized by the formation of the different dimensions portions different from other parts.

  According to a seventh aspect of the present invention, in the optical scanning device according to the sixth aspect, the sealing position of the upper cover member and the sealing position of the lower cover member in a plane perpendicular to the fastening direction of each cover member and the housing are from the center of the housing. When they are displaced in the radial direction, a different dimension portion is formed at a joint portion where the distance from the center of the housing is longer than that of the other portion, or the joint size is shorter at the joint portion where the distance is shorter. It is characterized in that a different dimension part smaller than the interval dimension of the other part is formed, or a different shape part is formed in each joint portion.

  According to an eighth aspect of the present invention, in the optical scanning device according to any one of the first to fifth aspects, the deformed portion is a separate part from the other portion of the seal member.

  A ninth aspect of the invention is an image forming apparatus comprising the optical scanning device according to any one of the first to ninth aspects.

  According to the optical scanning device and the image forming apparatus according to the present invention, the deformed portion having a different thickness is formed in the seal member located at the substantially central portion between the fastening positions that are easily deformed, or the housing and the cover of this portion Since different dimension portions having different distances at the joining positions of the members are arranged, the repulsive force of the seal member loaded on the housing and the cover member can be controlled, and deformation of the housing and the cover member can be prevented easily and at low cost. be able to.

  Embodiments as the best mode for carrying out the present invention will be described below with reference to the drawings.

  Hereinafter, an image forming apparatus according to the present embodiment will be described with reference to the drawings. In this example, it is assumed that a digital color writing device is provided as an image forming apparatus. FIG. 1 is a schematic cross-sectional view illustrating a digital color writing device of an image forming apparatus according to an embodiment. This writing apparatus has two polygon mirrors 1a and 1b having a reflection mirror on the side of a regular polygon and deflecting and scanning laser light by high-speed rotation, and a hot air flow generated from the polygon mirrors 1a and 1b. Soundproof glass 2a, 2b that is not transmitted to the lens, fθ lenses 3a, 3b that change the equiangular motion of the scanning beam by the polygon mirror 1a to constant velocity linear motion, yellow (Y), magenta (M), Mirrors 4a, 4b, 4c, 4d, 6a, 6b, 6c, 6d, 7a, 7b, 7c, 7d for guiding laser light to cyan (C) and black (Bk) photosensitive drums 9a, 9b, 9c, 9d And an L2 lens 5a, 5b, 5c, 5d for constricting in the sub-scanning direction, and dust-proof glass 8a, 8b, 8c, 8d for preventing dust from falling into the optical housing, and forming an image Wherein comprising photosensitive drum 9a, 9b, 9c, and 9d. The image forming apparatus includes the polygon mirrors 1a and 1b, the fθ lenses 3a and 3b, the mirrors 4a, 4b, 4c, 4d, 6a, 6b, 6c, 6d, 7a and 7b, and the L2 lenses 5a, 5b, 5c and 5d. It comprises an optical housing 10 in which the provided optical system is arranged, an upper cover member 11 and a lower cover member 12 for sealing the optical housing. In addition, each optical path is shown as 13a, 13b, 13c, 13d in the figure.

  Next, the image forming apparatus 15 provided with this digital color writing apparatus will be described. FIG. 2 is a schematic cross-sectional view showing a schematic configuration of the image forming apparatus. The image forming apparatus 15 according to this example includes the optical housing 10 of the digital color writing apparatus, and the photosensitive drums 9a, 9b, and 9c that form latent images by writing laser beams 13a, 13b, 13c, and 13d. , 9d, an intermediate transfer belt 14, a paper feed tray 16, and a fixing device 19. In the figure, an arrow A indicates the driving direction of the intermediate transfer belt 14.

  In such an image forming apparatus 15, the latent images formed on the photosensitive drums 9a, 9b, 9c, and 9d are developed by developing devices of various colors (not shown) to form toner images. The toner images of the respective colors are superimposed and transferred onto the intermediate transfer belt 14 to form a full color toner image, and this full color toner image feed is transferred to the printing paper conveyed from the paper feed tray 16. Then, the printing paper is conveyed to the fixing device 19, and the full color toner image is fixed on the printing paper and discharged outside the apparatus.

  Next, the optical scanning device according to the embodiment will be described. FIG. 3 is a perspective view showing an optical housing of the optical scanning device. In this example, the optical housing 10 that is a housing is fastened by a screw member 27 at fastening portions 21 to 26 of the lower cover member 12 that is a lower lid. The fastening portions 21 to 26 are disposed at a total of six locations, ie, two locations (fastening portions 21 and 22) in the center of the optical housing 10 and two locations (fastening portions 23, 24, 25, and 25) on the left and right and up and down. .

  Next, the seal member will be described. 4 is a plan view showing the lower cover member on which the seal member is disposed, FIG. 5 is a side perspective view showing a joined state of the optical housing and the lower cover member, and FIG. 6 is a joined state of the optical housing and the lower cover member. It is a perspective view from the lower part which shows.

  In such a lower cover member 12, a gap is provided between the lower cover member 12 and the optical housing 10 at a portion between the fastening portions 21 to 26 only by being fixed to the optical housing 10 by the six fastening portions 21 to 26. Will exist. The size of the gap depends on the amount of warpage of the lower cover member 12 and the state of the contact surface of the optical housing 10.

  Therefore, in this example, the seal member 17 is attached to the entire peripheral portion of the lower cover member 12 that contacts the mating surface of the optical housing 10 and the lower cover member 12 with a double-sided tape or the like, and is sealed by fastening with a screw member at the fastening portions 21 to 26. Sealing is improved by crushing the member 17.

  As shown in the drawing, since the shape of the lower cover member 12 is complicated and there are stepped portions, the seal member is not a single continuous member, but in this example, there are 10 divided seal members 17a to 17j as the lower cover member. I'm trying to put it on the entire circumference of 12 well. The seal member 17 may be attached to the optical housing 10 side.

  The seal member 17 is crushed by the optical housing 10 and the lower cover member 12 to generate a repulsive force. 7A and 7B show an optical scanning device, in which FIG. 7A is a schematic diagram showing an attachment state of an optical housing, a lower cover member, and a seal member, and FIG. 7B is a schematic diagram showing deformation of the optical housing and the lower cover member. FIG. 8 is a perspective view of the lower cover member showing a portion where the deformation of the seal member is large. As shown in FIG. 7, the optical housing 10 and the lower cover member 12 are not deformed in the vicinity of the fastening portion by the screw member 27 due to the fastening force by the screw member 27, but as the seal member 17 moves away from the fastening portion by the screw member 27. Since the repulsive force is supported only by the rigidity of the lower cover member 12 and the optical housing 10, deformation easily occurs. Here, as shown in FIG. 8, the portion where the deformation is likely to occur is often the center positions 31 to 36 of the adjacent fastening portions among the fastening portions 21 to 26.

  Therefore, in the present example, the deformed portion 18 whose thickness dimension is thinner than other portions is provided on the seal member 17 located in the central portions 31 to 36 that are easily deformed. 9A and 9B show an optical scanning device according to the embodiment. FIG. 9A is a schematic diagram of the optical scanning device, and FIG. 9B is a schematic diagram showing deformation of the optical housing and the lower cover member.

  In this example, the deformed portion 18 is formed at a portion corresponding to the central positions 31 to 36 of the seal member 17, for example, at the central position 35. The deformed portion 18 is configured so that the thickness dimension d2 is smaller than the thickness dimension d2 of the other part of the seal member 17. In this example, with this configuration, the repulsive force of the seal member 17 applied to the optical housing 10 can be reduced, and deformation of the optical housing 10 and the lower cover member 12 can be prevented. In this example, it is not necessary to change the shapes of the optical housing 10 and the lower cover member 12, and it is only necessary to change the shape of the seal member 17, so that it can be realized at low cost.

  In the above description, the case where the thickness dimension of a part of the seal member 17 is partially changed has been described. However, the deformed portion 18 can be a separate member from other portions. When the seal member 17 is disposed between the cover member and the optical housing 10, it may be disposed by being fixed with a double-sided tape or the like as described above. In this case, since the double-sided tape is disposed in the thickness direction of the seal member, the cost increases if the deformed portion 18 is integrally provided on the seal member when the seal member is manufactured. Therefore, cost reduction is achieved by using the deformed portion 18 as a separate member.

  Next, an optical scanning device according to a second embodiment will be described. 10A and 10B show an optical scanning device according to the second embodiment. FIG. 10A is a schematic side view of the optical scanning device, and FIG. 10B is a schematic diagram showing deformation amounts of the optical housing and the lower cover member. In this example, a concave portion 41 is formed on the upper surface of the optical housing 10 with which the seal member 17 abuts as a different dimension portion in which the distance between the optical housing 10 and the lower cover member 12 is larger than the distance between other portions. Yes. In this example, with this configuration, the crushing amount of the seal member 17 in the concave portion 41 can be reduced, and as a result, the repulsive force of the seal member 17 can be reduced, and deformation of the optical housing 10 and the lower cover member 12 can be prevented.

  Next, a third embodiment will be described. In this example, not only the lower cover member 12 but also the upper cover member 11 is disposed in the optical housing 10. FIG. 11 is a schematic diagram showing an optical housing in which an upper cover member and a lower cover member are arranged, and FIG. 12 is a schematic diagram showing a case where deformation occurs in the optical housing in which an upper cover member and a lower cover member are arranged. In this example, a seal member 17 a is disposed between the optical housing 10 and the upper cover member 11, and a seal member 17 b is disposed between the optical housing 10 and the lower cover member 12.

  First, as shown in FIG. 11, when viewed from a plane perpendicular to the fastening direction of the upper cover member 11 and the lower cover member 12 and the optical housing 10, the end positions of the upper cover member 11 and the lower cover member 12 coincide. (The upper cover member 11 and the lower cover member 12 overlap in the plan view), the seal member 17a is provided between the upper cover member 11 and the optical housing 10, and the lower cover member 12 and the optical housing 10 are provided. Even if the sealing member 17b is disposed on the entire circumference of the optical housing 10, the repulsive force of the sealing members 17a and 17b to the optical housing 10 is offset up and down, so that the optical housing 10 is not easily deformed. However, as shown in FIG. 12, when the end positions of the upper cover member 11 and the lower cover member 12 are displaced, that is, the arrangement positions of the seal member 17a and the seal member 17b are radial from the center of the housing (see FIG. In the case of a shift in the middle left direction), the larger the shift amount, the larger the difference in the repulsive force to the optical housing 10, and the optical housing 10 will be deformed.

  FIG. 13 is a schematic diagram showing the configuration of the optical scanning device according to the third embodiment. In FIG. 12, the distance in the radial direction from the central portion of the optical housing 10 of the seal member 17a is longer in the upper cover member. For this reason, among the sealing members 17a arranged on the upper cover member 11, the thickness dimension d4 of the protruding portion 17c protruding from the lower cover member 12 is made smaller than the thickness dimension d3 of the other part of the sealing member 17a, The deformation of the optical housing 10 is reduced.

  Further, in this example, the same effect can be obtained by making the thickness dimension of the seal member 17b on the lower cover member 12 side, which is short from the center of the optical housing 10 of the seal member 17a, larger than the thickness dimension of other portions. And changing the thickness of both the sealing members a and 17b has an effect more than changing one of the thicknesses.

  In the second embodiment, by changing the thickness dimension of the seal members a and 17b, the joining position of the upper cover member 11 and the lower cover member 12 to the optical housing 10 is radial from the central portion of the optical housing 10. The optical housing 10 is prevented from being deformed when it is shifted to the upper cover member 11, the lower cover member 12 and the optical housing 10 so that the distance between the upper cover member 11, the lower cover member 12 and the optical housing 10 is changed. By forming the recess, the deformation amount of the seal members 17a and 17b can be controlled to prevent the optical housing 10 from being deformed. Thus, in order to change the space | interval dimension of both the cover members 11 and 12 and the optical housing 10, in addition to providing another member, the shape of the optical housing 10 or the cover members 11 and 12 can be changed.

  Note that it is preferable to use a method of changing the shape of the cover members 11 and 12 at the initial stage of the design of the optical scanning device, and when it becomes costly to change the shape of the cover members 11 and 12. It is preferable to change the seal thickness because it is low cost.

1 is a schematic cross-sectional view illustrating a digital color writing device of an image forming apparatus according to an embodiment. 1 is a schematic cross-sectional view illustrating a schematic configuration of an image forming apparatus according to an embodiment. It is a perspective view which shows the optical housing of an optical scanning device. It is a top view which shows the lower cover member by which the sealing member is arrange | positioned. It is a perspective view from the side which shows the joining state of an optical housing and a lower cover member. It is a perspective view from the lower part which shows the joining state of an optical housing and a lower cover member. FIGS. 2A and 2B show an optical scanning device, in which FIG. 1A is a schematic diagram illustrating an attachment state of an optical housing, a lower cover member, and a seal member, and FIG. 2B is a schematic diagram illustrating deformation of the optical housing and the lower cover member. It is a perspective view of the lower cover member which shows a part with a big deformation | transformation of a sealing member. The optical scanning device which concerns on an Example is shown, (a) is a schematic diagram of an optical scanning device, (b) is a schematic diagram which shows a deformation | transformation of an optical housing and a lower cover member. The optical scanning device which concerns on 2nd Example is shown, (a) A schematic side view of an optical scanning device, (b) is a schematic diagram which shows the deformation amount of an optical housing and a lower cover member. It is a schematic diagram which shows the optical housing by which the upper cover member and the lower cover member are arrange | positioned. It is a schematic diagram which shows the case where a deformation | transformation arises in the optical housing by which the upper cover member and the lower cover member are arrange | positioned. It is a schematic diagram which shows the structure of the optical scanning device based on 3rd Example.

Explanation of symbols

1a, 1b Polygon mirrors 2a, 2b Soundproof glass 3a, 3b fθ lenses 4a, 4b, 4c, 4d, 6a, 6b, 6c, 6d, 7a, 7b, 7c, 7d Mirrors 8a, 8b, 8c, 8d Dustproof glass 9a, 9b, 9c, 9d Photosensitive drum 10 Optical housing 11 Upper cover member 12 Lower cover members 13a, 13b, 13c, 13d Writing laser beam 14 Intermediate transfer belt 15 Image forming apparatus 16 Paper feed trays 17a to 17j Split seal member 17 Seal Member 17a Seal member 17b Seal member 17c Protruding portion 18 Deformed portion 19 Fixing devices 21 to 26 Fastening portion 27 Screw members 31 to 36 Center portion 41 Concave portion

Claims (9)

A light source, and scanning means for irradiating the light irradiation target with light from the light source and scanning the light irradiation target;
An optical element provided on an optical path from the light source to the light irradiation target;
A housing for housing an optical system including the scanning unit and the optical element;
One or more cover members for covering the housing;
In an optical scanning device comprising a seal member that is disposed in a gap between the housing and the cover member to ensure hermeticity,
The seal member is disposed on the entire circumference of the cover member,
An optical device characterized in that a deformed portion having a thickness dimension different from that of other portions of the seal member is formed in at least one portion of the seal member positioned substantially in the center of the fastening position where each cover member is fastened to the housing. Scanning device.   2. The optical scanning device according to claim 1, wherein a thickness dimension of the deformed portion is smaller than a thickness dimension of other portions of the seal member.   2. The optical scanning device according to claim 1, wherein a thickness dimension of the deformed portion is larger than a thickness dimension of other portions of the seal member. A light source, and scanning means for irradiating the light irradiation target with the light from the light source and scanning it,
An optical element provided on an optical path from the light source to the light irradiation target;
A housing for housing an optical system including the scanning unit and the optical element;
An upper cover member covering the upper side of the housing;
A lower cover member covering the lower side of the housing;
In the optical scanning device comprising the upper cover member, the lower cover member, and a seal member that is disposed in a gap between the housing and ensures sealing performance,
The seal member is disposed on the entire circumference of the upper cover member and the lower cover member,
When the sealing position of the upper cover member and the arrangement position of the seal of the lower cover member in a plane perpendicular to the fastening direction of each cover member and the housing are shifted in the radial direction from the center of the housing, the sealing member is arranged at the position. An optical scanning device characterized in that a deformed portion having a thickness dimension different from that of other portions of the seal member is formed. When the sealing position of the upper cover member and the sealing position of the lower cover member in the plane perpendicular to the fastening direction of each cover member and the housing are shifted in the radial direction from the center of the housing, the center of the housing of the two seal members A deformed portion having a thickness dimension smaller than the thickness dimension of the other portion is formed on the seal member having a longer distance from the other, or the thickness dimension of the seal member having a shorter distance from the other portion. Forming a deformed part larger than the thickness dimension,
Or
5. The optical scanning device according to claim 4, wherein each sealing member is formed with a deformed portion. A light source, and scanning means for irradiating the light irradiation target with light from the light source and scanning the light irradiation target;
An optical element provided on an optical path from the light source to the light irradiation target;
A housing for housing an optical system including the scanning unit and the optical element;
An upper cover member covering the upper side of the housing;
A lower cover member covering the lower side of the housing;
In the optical scanning device comprising the upper cover member, the lower cover member, and a seal member that is disposed in a gap between the housing and ensures sealing performance,
The seal member is disposed on the entire circumference of the upper cover member and the lower cover member,
When the sealing position of the upper cover member and the sealing position of the lower cover member in a plane perpendicular to the fastening direction of each cover member and the housing are shifted in the radial direction from the center of the housing, the position where the shift is generated An optical scanning device characterized in that the upper cover member or the gap between the lower cover member and the housing is formed with a different size portion different from other portions. When the sealing position of the upper cover member and the sealing position of the lower cover member in the plane perpendicular to the fastening direction of each cover member and the housing are displaced in the radial direction from the center of the housing, the joint location where the distance from the center of the housing is long Forming a different dimension part whose spacing dimension is larger than the spacing dimension of the other part, or forming a different dimension part whose spacing dimension is smaller than the spacing dimension of the other part at the joint portion where the distance is short,
Or
7. The optical scanning device according to claim 6, wherein a deformed portion is formed at each junction. 6. The optical scanning device according to claim 1, wherein the deformed portion is a separate part from other portions of the seal member. An image forming apparatus comprising the optical scanning device according to claim 1.