JP2009014983A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an image forming apparatus suppressing banding in an output image. <P>SOLUTION: Coil springs 60 provided in brackets 54 energize an abutting member 62 to a short side surface part 64A in a side plate member 64. Compared with a case in which a long side of a section of the side plate member 64 and the abutting member 62 are abutted, sectional secondary moment in the bending direction is greater. Therefore, the side plate member 64 is not deformed even when the coil springs 60 energize the abutting member 62 to the short side surface parts 64A in the side plate members 64. Thus, since a central part of the LPH20 supported by the both end parts is energized to the side plate members 64, the distance between supporting points is made shorter and natural frequency of LPH20 can be made higher. In addition, the banding in the output image can be suppressed. Furthermore, since the side plate member 64 is to be a plate member, part of the housing supporting the LPH20 can be used and the apparatus is not made large in size. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus including a light emitter in which a plurality of light emitting elements for exposing the surface of a photosensitive drum are arranged.

In the image forming apparatus described in Patent Document 1, a light emitter that extends in the axial direction of the photosensitive drum is disposed along the surface of the photosensitive drum. At both ends of the light emitter, contact pins extending toward the photosensitive drum are provided. Then, by bringing the tip of the contact pin into contact with the bearing member of the photosensitive drum, the focal length of the light emitter can be maintained at a predetermined distance, and a high quality output image can be obtained. ing.
JP 2001-130047 JP

  However, since the abutment pin is not provided at the center of the light emitter, when an external force is applied to the light emitter, the light emitter is deformed at the center of the light emitter and the focal length of the light emitter is set to a predetermined distance. I can't keep it. If a contact pin is provided in the central portion of the light emitter, it must be brought into contact with the exposure area of the photosensitive drum, so that the contact pin cannot be provided in the central portion of the light emitter.

  Therefore, in the light emitter of this image forming apparatus, the central portion of the light emitter is deformed by disturbance due to vibration of a motor or the like that drives each portion, and the light emitter vibrates. It is conceivable that the focal length of the light emitter changes due to the vibration of the light emitter, and streaks (so-called banding) occur in the output image.

  An object of the present invention is to suppress banding of an output image in consideration of the above fact.

  An image forming apparatus according to a first aspect of the present invention includes a photosensitive drum on which a latent image is formed by light irradiation, and extends along the axial direction of the photosensitive drum, and emits light to the surface of the photosensitive drum. A plurality of light emitting elements to be irradiated are arranged, and a detachable light emitter having both ends supported by a frame member, and supported by the frame member and extending in the axial direction of the photosensitive drum, with respect to the axial direction. A side plate member whose cross-sectional shape in the orthogonal direction is a rectangular shape having a short side and a long side; and a contact member that is provided in the light emitter and contacts a short side surface portion that forms a short side of the cross section of the side plate member; And an urging member that urges the abutting member toward the short side surface portion.

  According to the above configuration, the light emitter in which a plurality of light emitting elements for irradiating light on the surface of the photosensitive drum is arranged so as to extend along the axial direction of the photosensitive drum. Both ends of the light emitter are supported by a frame member, and can be detached.

  Further, a side plate member having a rectangular cross section having a short side and a long side extends in the axial direction of the photosensitive drum and is supported by the frame member.

  Further, the abutting member provided in the light emitter abuts on the short side surface portion that forms the short side of the cross section of the side plate member, and the urging member urges the abutting member toward the short side surface portion.

  That is, when the abutting member is brought into contact with the long side surface portion forming the long side of the cross section of the side plate member and the urging member urges the abutting member toward the long side surface portion, the bending direction of the side plate member is increased. Large cross section second moment. For this reason, even if the urging member urges the abutting member to the short side surface portion of the side plate member, the abutting member is urged to the side plate member without greatly deforming the side plate member. Thus, by bringing the light emitters supported at both ends into contact with the side plate members, the distance between the support points is shortened, and the natural frequency of the light emitter can be increased.

  Further, even when the light emitter is vibrated by vibration of a motor or the like that drives each part, the amplitude of the light emitter is reduced, and therefore banding of the output image can be suppressed.

  Further, since the side plate member may be a member having a rectangular cross section extending in the axial direction of the photosensitive drum, a part of the housing that supports the light emitter can be used. For this reason, the natural frequency of the light emitter can be increased without increasing the size of the apparatus.

  An image forming apparatus according to a second aspect of the present invention is the image forming apparatus according to the first aspect, wherein the side plate member is disposed so that the short side surface portion faces a focal direction of the light emitter.

  According to the said structure, the side-plate member is arrange | positioned so that a short side surface part may face the focus direction of a light-emitting device. Thereby, the urging member urges the abutting member that abuts on the short side surface part toward the focal direction of the light emitter.

  Thus, the natural frequency of the light emitter in the focal direction can be increased by biasing the contact member toward the short side surface portion in the focal direction of the light emitter.

  An image forming apparatus according to a third aspect of the present invention is the image forming apparatus according to the first aspect, wherein the side plate member is disposed so that the short side surface portion faces an orthogonal direction orthogonal to a focal direction of the light emitter. Features.

  According to the said structure, the side-plate member is arrange | positioned so that a short side surface part cut may face the orthogonal direction orthogonal to the focus direction of a light-emitting device. Thereby, the urging member urges the abutting member that abuts on the short side surface portion in the orthogonal direction orthogonal to the focal direction of the light emitter.

  In this way, the natural frequency of the light emitter in the orthogonal direction orthogonal to the focal direction is increased by urging the contact member toward the short side surface portion in the orthogonal direction orthogonal to the focal direction. Can do.

  An image forming apparatus according to a fourth aspect of the present invention is the image forming apparatus according to the first aspect, wherein the short side surface portion faces the focal direction of the light emitter, and the short side surface portion is the focal direction of the light emitter. A second side plate member facing in an orthogonal direction perpendicular to the first side plate member, provided on the contact member, a first contact portion contacting the short side surface portion of the first side plate member, and provided on the contact member, A second abutting portion that abuts the short side surface portion of the second side plate member, a first urging member that urges the first abutting portion against the first side plate member, and the second abutting portion And a second urging member for urging the second side plate member.

  According to the above configuration, the short side surface portion of the first side member faces the focal direction of the light emitter, and further, the short side surface portion of the second side plate member faces the orthogonal direction orthogonal to the focal direction of the light emitter. ing.

  The contact member is provided with a first contact portion that contacts the short side surface portion of the first side plate member and a second contact portion that contacts the short side surface portion of the second side plate member.

  Further, the first urging member urges the first abutting portion of the abutting member to the short side surface portion of the first side plate member, and the second urging member urges the second abutting portion of the abutting member to the second side plate. It is biased to the short side surface portion of the member.

  In this way, the natural frequency of the light emitter can be increased in the focal direction of the light emitter and in the orthogonal direction perpendicular to the focal direction.

  An image forming apparatus according to a fifth aspect of the present invention is the image forming apparatus according to any one of the first to fourth aspects, wherein the contact member is provided at a central portion in a longitudinal direction of the light emitter.

  According to the said structure, the contact member is provided in the longitudinal direction center part of the light-emitting device. Thereby, since a light-emitting device is supported by both ends and a center part, compared with the case where it is not supported by a center part, the natural frequency of a light-emitting device can be made low effectively.

  According to the image forming apparatus of the present invention, banding of the output image can be suppressed.

  An image forming apparatus according to a first embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 6, the image forming apparatus 10 is stretched around a plurality of rollers 12 inside a casing 11 constituting the main body, and is conveyed in the direction of arrow A by driving a motor (not shown). An endless belt-like intermediate transfer belt 14 is provided.

  The image forming apparatus 10 corresponds to the formation of a color image, and forms an image forming unit that forms toner images corresponding to four colors of yellow (Y), magenta (M), cyan (C), and black (K). 15Y, 15M, 15C, and 15K are arranged along the longitudinal direction of the intermediate transfer belt 14.

  In addition, about the member provided for each color, it adds and shows the alphabet (Y / M / C / K) which shows each color at the end of a code | symbol, but when it demonstrates without distinguishing especially a color, The description will be made by omitting the alphabet at the end of the code.

  The image forming unit 15 includes a photosensitive drum 16 that is rotated counterclockwise by a driving unit including a motor and a gear (not shown).

  Further, a charging roller 18 for uniformly charging the surface of the photosensitive drum 16 to a predetermined potential is disposed on the peripheral surface of the photosensitive drum 16. The charging roller 18 is a conductive roller, and its peripheral surface is in contact with the peripheral surface of the photosensitive drum 16, and is arranged so that the axial direction of the charging roller 18 coincides with the axial direction of the photosensitive drum 16. Has been.

  Further, an LED (light emitting diode) as a light emitting element for forming an electrostatic latent image on the photosensitive drum 16 is used as a light source on the peripheral surface downstream of the charging roller 18 in the rotation direction of the photosensitive drum 16. An LED print head (LPH) 20 as a light emitter is provided extending in the axial direction of the photosensitive drum 16. Hereinafter, the LED print head 20 is referred to as LPH 20.

  As shown in FIG. 5, the LPH 20 includes a plurality of LEDs arranged in a line shape, an LED array 28 in which LED chips 30 are arranged, and a plurality of LEDs in order to image light output from the LEDs on the surface of the photoreceptor. A selfoc lens array 32 in which rod lenses are arranged and a rectangular parallelepiped support member 38 that supports the selfoc lens array 32 are configured.

  Specifically, the LED array 28 is configured by arranging a plurality of LED chips 30 on a printed board 28A on which a circuit for supplying various signals for controlling the driving of the LED array 28 is formed. The number of LEDs in the entire LED array 28 corresponds to the number of pixels (dots) corresponding to the resolution, for example, paper of A3 size (420 mm × 297 mm), and printing is performed at 600 dpi in the LED arrangement direction (LPH longitudinal direction). In this case, about 7020 are provided.

  In the present embodiment, the direction in which the LPH 20 emits light toward the photosensitive drum 16 is the focal direction (the X direction shown in FIG. 5), and the direction orthogonal to the focal direction and the axial direction of the photosensitive drum 16 is orthogonal. The direction (Y direction shown in FIG. 5).

  Further, the LED chips 30 are arranged in the longitudinal direction of the LPH 20 by making the arrangement direction of the respective LEDs coincide with the longitudinal direction of the LPH 20 and alternately shifting the mounting positions in the orthogonal direction (Y direction) by a predetermined pitch. Arrangement) and attached to the printed circuit board 28A.

  Since the LED chips 30 are arranged in a staggered manner in this way, the LPH longitudinal direction positions of the LED chips 30 adjacent to each other in the longitudinal direction of the LPH 20 can be arranged in an overlapping manner, and the intervals between the LEDs may vary. There is no such thing.

  The LED chips 30 may be arranged in a line regardless of the staggered arrangement as long as the LEDs are arranged at equal intervals in the LPH longitudinal direction. May be arranged only.

  The SELFOC lens array 32 is provided between the LED array 28 and the photosensitive drum 16 as an imaging lens. The SELFOC lens array 32 is composed of, for example, refractive index distribution type rod lenses arranged at a pitch corresponding to each pixel (dot) corresponding to the resolution, and sensitizes the light beam emitted from each LED. An image is formed on the body drum 16. Details of the LPH 20 will be described later.

  The LPH 20 having the above structure forms an electrostatic latent image on the photosensitive drum 16 by irradiating the photosensitive drum 16 with a light beam according to image data.

  Further, as shown in FIG. 6, an electrostatic latent image formed on the photosensitive drum 16 is placed on a peripheral surface downstream of the LPH 20 in the rotation direction of each photosensitive drum 16 with a predetermined color (yellow / magenta). / Cyan / Black) is provided with a developing device 22 for developing the toner image to form a toner image.

  The developing device 22 has a cylindrical developing roller 24 that is disposed in proximity to the photosensitive drum 16 and is rotatably provided. A developing bias is applied to the developing roller 24, and the toner loaded in the developing device 22 is attached to the peripheral surface. As the developing roller 24 rotates, the toner attached to the developing roller 24 is conveyed to the surface of the photosensitive drum 16, and the toner is rubbed against the photosensitive drum 16 to form an electrostatic latent image formed on the photosensitive drum 16. The image is developed.

  Further, a transfer roller 25 for transferring the toner image on each photosensitive drum 16 to the intermediate transfer belt 14 is provided on the peripheral surface downstream of the developing device 22 in the rotation direction of each photosensitive drum 16. . The transfer roller 25 is charged to a predetermined potential and rotates clockwise to convey the intermediate transfer belt 14 at a predetermined speed and sequentially face the photosensitive drum 16. As a result, the transfer roller 25 transfers the toner on the photosensitive drum 16 onto the intermediate transfer belt 14.

  Further, a cleaning blade 26 that collects residual toner such as transfer residual toner and retransfer toner on the photosensitive drum 16 is disposed downstream of the transfer roller 25 on the peripheral surface of the photosensitive drum 16. The cleaning blade 26 is arranged so that one side is in contact with the photosensitive drum 16, and toner remaining on the photosensitive drum 16 without being transferred to the intermediate transfer belt 14, or on the photosensitive drum 16 at the time of transfer. The toner of other colors that have adhered to the toner is scraped off and collected.

  Here, the toner images of different colors formed by the image forming units 15 are transferred on the belt surface of the intermediate transfer belt 14 so as to overlap each other. As a result, a color toner image is formed on the intermediate transfer belt 14. In this embodiment, the toner image in which the four color toner images are transferred in a superimposed manner is referred to as a final toner image.

  On the downstream side of the four image forming units 15 in the transport direction of the intermediate transfer belt 14, a transfer device 34 including two rollers 34A and 34B facing each other is disposed. The final toner image formed on the intermediate transfer body belt 14 is sent between the rollers 34A and 34B, taken out from the paper tray 36 provided at the bottom of the image forming apparatus 10, and is similarly supplied to the rollers 34A and 34B. It is transferred to the sheet material P that has been conveyed in between.

  In addition, a fixing device 40 including a heating roller 40A and a pressure roller 40B is disposed in the conveyance path of the sheet material P to which the final toner image has been transferred. The sheet material P conveyed to the fixing device 40 is nipped and conveyed by the heating roller 40A and the pressure roller 40B, whereby the toner on the sheet material P melts and is pressed against the sheet material P to be fixed. .

  On the other hand, a cleaner 42 that collects toner remaining on the intermediate transfer belt 14 without being transferred to the sheet material P by the transfer device 34 is disposed downstream of the transfer device 34 in the conveyance direction of the intermediate transfer belt 14. Has been. The cleaner 42 is provided with a blade 44 so as to be in contact with the intermediate transfer body belt 14, and collects residual toner by rubbing it.

  In the image forming apparatus 10 configured as described above, an image is formed as follows.

  First, the charging roller 18 uniformly negatively charges the surface of the photosensitive drum 16 with a predetermined charging portion potential. Further, exposure is performed by the LHP 20 so that the charged image portion on the photosensitive drum 16 has a predetermined exposure portion potential, and an electrostatic latent image is formed on the photosensitive drum 16.

  That is, an electrostatic latent image corresponding to an image is formed on each photosensitive drum 16 by turning on and off the laser beam of the LHP 20 based on image data supplied from a control unit (not shown).

  Further, when the electrostatic latent image on the rotating photosensitive drum 16 passes through the developing roller 24 provided in the developing device 22, the toner of the developer G adheres to the electrostatic latent image by electric force, and the electrostatic latent image Is visualized as a toner image.

  The visualized toner images of the respective colors are sequentially transferred to the intermediate transfer body belt 14 by the electric force of the transfer roller 25, and a color final toner image is formed on the intermediate transfer body belt 14.

  This final toner image is fed between rollers 34A and 34B provided in the transfer device 34, taken out from the paper tray 36, and transferred to the sheet material P that is also conveyed between the rollers 34A and 34B. .

  Further, the toner image transferred to the sheet material P is fixed by the fixing device 40, and the sheet material P is discharged outside the device.

  Next, the LPH 20 and the photosensitive drum 16 will be described in detail.

  As shown in FIGS. 1 and 2, the photosensitive drum 16 has a cylindrical shaft portion 50 projecting outward from both end faces. Further, cylindrical bearings 52 are respectively provided at both ends of the photosensitive drum 16 to support the photosensitive drum 16 in a rotatable manner.

  As shown in FIG. 1, LPHs 20 are disposed below the photoconductive drum 16 so as to face the photoconductive drum 16, and contact pins extending toward the bearings 52 at both ends of the LPH 20. 46 are provided. The tip of the contact pin 46 is in contact with the surface of the bearing 52 (see FIG. 4), and the focal direction (X direction) of the LPH 20 with respect to the photosensitive drum 16 is maintained at a predetermined distance.

  Further, brackets 54 having a U-shaped cross section that is fixed to a frame member (not shown) and opened upward are provided at both ends of the LPH 20.

  As shown in FIG. 4, a hemispherical projection 56 is provided on the inner side of the standing plate 54 </ b> A of the bracket 54, and the standing plate 54 </ b> A facing the projection 56 has a square cross section. A leaf spring 58 is provided. The end of the leaf spring 58 is fixed to the standing plate 54A, and the leaf spring 58 urges the side surface portion 38A of the support member 38 of the LPH 20 and presses the support member 38 against the protrusion 56. With this configuration, both end portions of the LPH 20 are supported by the bracket 54.

  On the other hand, as shown in FIG. 1, a plate-like side plate member 64 extending in the axial direction of the photosensitive drum 16 is stretched between the brackets 54 at both ends. Both end portions of the side plate member 64 are fixed to the bracket 54 by plate-like brackets 66 and bolts 68.

  As shown in FIG. 3, the cross section of the side plate member 64 perpendicular to the axial direction of the photosensitive drum has a long side extending in the focal direction (X direction) and a short side extending in the orthogonal direction (Y direction). It is made into the rectangular shape which has. A rectangular parallelepiped contact member 62 that contacts a short side surface portion 64 </ b> A that forms a short side of the cross section of the side plate member 64 is disposed below the side plate member 64.

  As shown in FIGS. 1 and 3, the abutting member 62 is fixed to the central portion of the support member 38 in the longitudinal direction (axial direction of the photosensitive drum 16).

  As shown in FIG. 4, a coil spring 60 extending in the focal direction (X direction) is provided between the bottom plate 54 </ b> B of the bracket 54 and the bottom surface portion 38 </ b> B of the support member 38.

  The coil spring 60 urges the contact member 62 fixed to the side surface portion 38A of the support member 38 to the short side surface portion 64A of the side plate member 64, and further urges the tip end portion of the contact pin 46 to the bearing 52. To do.

  Here, when the LPH 20 is vibrated by the vibration of a motor or the like that drives each part, the LPH 20 vibrates, the focal length of the LPH 20 with respect to the photosensitive drum 16 changes, and a streak (so-called banding) occurs in the output image. There is.

  However, in this embodiment, as described above, the contact member 62 provided on the LPH 20 contacts the short side surface portion 64A that forms the short side of the cross section of the side plate member 64, and the coil spring 60 is the contact member. 62 is urged toward the short side surface portion 64A.

  That is, as compared with the case where the long side surface portion 64B (see FIG. 3) that forms the long side of the cross section of the side plate member 64 is brought into contact with the contact member, the sectional moment in the bending direction of the side plate member 64 is large. For this reason, even if the coil spring 60 urges the contact member 62 against the short side surface portion 64 </ b> A of the side plate member 64, the side plate member 64 is not deformed.

  Thus, since the center part of LPH20 supported by both ends is urged by the side plate member 64, the distance between the support points is shortened and the natural frequency of LPH20 in the focal direction (X direction shown in the figure) is increased. be able to.

  Furthermore, even if the LPH 20 is vibrated in the focal direction (X direction shown in the figure) by vibration of a motor or the like that drives each part, the amplitude of the LPH 20 becomes small, and therefore banding of the output image can be suppressed.

  Further, since the side plate member 64 may be a plate member having a rectangular cross section extending in the axial direction of the photosensitive drum 16, a part of the housing that supports the LPH 20 can be used. In addition, the natural frequency of the LPH 20 can be increased.

  Further, since the LPH 20 supported at both ends is supported by the side plate member 64 at the longitudinal center portion, the natural frequency of the LPH 20 can be effectively lowered as compared with the case where the LPH 20 is not supported at the center portion.

  Next, the image forming apparatus 10 according to the second embodiment will be described with reference to FIGS.

  In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In this embodiment, as shown in FIGS. 7 and 8, as in the first embodiment, the short side surface portion 70 </ b> A of the side plate member 70 does not face the focal direction (X direction) and is orthogonal (Y Direction).

  Further, on the side of the side plate member 70, a rectangular parallelepiped contact member 78 that contacts the short side surface portion 70A that forms the short side of the cross section of the side plate member 70 is the longitudinal direction of the support member 38 of the LPH 20 (photosensitive drum). (16 axial direction) It is being fixed to the center part.

  On the other hand, as shown in FIG. 7, both ends of the LPH 20 are provided with brackets 72 that are fixed to a frame member (not shown) and have a U-shaped cross-section with the upper part opened.

  As shown in FIG. 9, a hemispherical projection 74 is provided inside the standing plate 72 </ b> A of the bracket 72, and the standing wall 72 </ b> A facing the projection 74 is orthogonal (Y direction). An extending coil spring 76 is provided.

  The coil spring 76 urges the side surface portion 38 </ b> A of the support member 38 and presses the support member 38 against the protrusion 74. With this configuration, both end portions of the LPH 20 are supported by the bracket 72.

  Further, the coil spring 76 biases the contact member 78 fixed to the support member 38 toward the short side surface portion 70 </ b> A of the side plate member 70.

  For this reason, the distance between the support points is shortened, and the natural frequency of the LPH 20 in the orthogonal direction (Y direction shown in the figure) can be increased.

  Next, the image forming apparatus 10 according to the third embodiment will be described with reference to FIGS.

  In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In this embodiment, as shown in FIGS. 10 and 11, in addition to the side plate member 64 in which the short side surface portion 64 shown in the first embodiment is directed in the focal direction (X direction), the short side surface portion 80A is orthogonal. A side plate member 80 facing in the direction (Y direction) is provided.

  Also, below the side plate member 64, a short side surface portion 64 </ b> A that forms a short side of the cross section of the side plate member 64 and a rectangular parallelepiped contact member 82 that contacts at the first contact portion 82 </ b> A are provided. Is fixed to the center of the support member 38 in the longitudinal direction (axial direction of the photosensitive drum 16). Further, the second contact portion 82 </ b> B of the contact member 82 is in contact with the short side surface portion 80 </ b> A that forms the short side of the cross section of the side plate member 80.

  On the other hand, as shown in FIG. 10, brackets 84 having a U-shaped cross section that is fixed to a frame member (not shown) and opened upward are provided at both ends of the LPH 20.

  As shown in FIG. 12, a hemispherical projection 86 is provided on the inside of the standing plate 84 </ b> A of the bracket 84, and the standing plate 84 </ b> A facing the projection 86 has an orthogonal direction (Y direction). A coil spring 88 extending to) is provided.

  The coil spring 88 biases the side surface portion 38A of the support member 38 and presses the support member 38 against the protrusion 86. With this configuration, both end portions of the LPH 20 are supported by the bracket 84.

  Further, as shown in FIG. 11, the coil spring 88 biases the contact member 82 fixed to the support member 38 toward the short side surface portion 80 </ b> A of the side plate member 80.

  Further, as shown in FIG. 12, a coil spring 90 extending in the focal direction (X direction) is provided between the bottom plate 84B of the bracket 84 and the bottom surface portion 38B of the support member 38.

  The coil spring 90 urges the tip of the contact pin 46 toward the bearing 52, and further, the contact member 82 fixed to the support member 38 is connected to the short side surface portion of the side plate member 64 as shown in FIG. Energize to 64A.

  In this manner, the distance between the support points can be shortened, and the natural frequency of the LPH 20 in the focal direction (X direction) and the orthogonal direction (Y direction) can be increased.

  Next, an image forming apparatus 10 according to a fourth embodiment will be described with reference to FIGS.

  In addition, about the same member as 3rd Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In this embodiment, as shown in FIGS. 13 and 14, the shape of the contact member 94 is not a rectangular parallelepiped as in the third embodiment, and the contact member 94 is a cross section inclined by 90 degrees. It is T-shaped.

  Specifically, the abutting member 94 is fixed to the support member 38 and extends in the orthogonal direction (Y direction). The distal end member is fixed to the distal end of the fixing member 96 and extends in the focal direction (X direction). 98 is provided.

  The portion of the fixing member 96 that faces the short side surface portion 64A of the side plate member 64 is the first contact portion 96A, and the portion of the tip member 98 that faces the short side surface portion 80A of the side plate member 80 is the second contact portion. The contact portion is 98A.

  Next, an image forming apparatus 10 according to a fifth embodiment will be described with reference to FIGS.

  In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In this embodiment, as shown in FIG. 15, unlike the first embodiment, an exposure position (see FIG. 16) at which the surface of the photosensitive drum 16 can be exposed and a retracted position (see FIG. 16) away from the photosensitive drum 16. 17), a retract mechanism 100 for moving the LPH 20 is provided.

  Specifically, a flat side plate member 102 is spanned between the bottom plates 54B of the brackets 54 provided at both ends of the LPH 20. In the side plate member 102, two rectangular holes 103 penetrating from the upper surface to the lower surface are formed with a predetermined distance therebetween.

  A rectangular parallelepiped support wall 104 is provided below the side plate member 102 and is fixed to a bracket (not shown) or the like and extends in the axial direction of the photosensitive drum 16. The support wall 104 is provided with a cylindrical pin 106 protruding from the side surface of the support wall 104 in the orthogonal direction. The pins 106 are provided at two locations separated by a predetermined distance.

  Further, on the lower side of the side plate member 102, plate-shaped cams 108 having an elliptical outer shape are arranged at two locations. In the central portion of the cam 108, a long hole 110 having a predetermined size and penetrating from one surface of the cam 108 to the other surface is formed. In addition, a cylindrical pin 112 protrudes from one end of the long axis direction of the cam 108 in the orthogonal direction (Y direction).

  Further, a plate-like link member 114 extending in the axial direction of the photosensitive drum 16 is disposed adjacent to the cam 108. Two holes (not shown) larger than the outer diameter of the pin 112 are formed in the link member 114.

  Here, the upper end portion of the cam 108 is inserted into the hole portion 103 of the side plate member 102 and comes into contact with the bottom surface of the LPH 20, and the pin 106 is inserted into the long hole 110 of the cam 108. The E-ring is engaged. Then, the pin 112 is inserted through the hole of the link member 114, and an E ring (not shown) is engaged with the tip of the pin 112.

  The left end portion of the link member 114 is connected to a driving means including a motor or a cam mechanism (not shown). The driving means enables the link member 114 to slide back and forth in the axial direction of the photosensitive drum 16. Yes.

  Further, the LPH 20 is provided with a slide mechanism (not shown) and can move in the focal direction (X direction).

  With this configuration, as shown in FIG. 17, when the LPH 20 does not expose the surface of the photosensitive drum 16, the elliptical plate-like cam 108 is tilted by the driving means via the link member 114, and the LPH 20 is exposed to light. It is arranged at a retracted position away from the body drum 16.

  When the LPH 20 exposes the surface of the photosensitive drum 16, the link member 114 is pushed in the direction of arrow A by the driving means. Thereby, as shown in FIG. 16, the pin 112 inserted into the hole of the link member 114 moves in the arrow A direction. When the pin 112 moves, the cam 108 rotates while being regulated by the pin 106 and stops at a position extending in the focal direction (X direction).

  As the cam 108 rotates, the LPH 20 in contact with the upper end of the cam 108 also slides in the focal direction (X direction), and the LPH 20 stops at an exposure position where the surface of the photosensitive drum 16 can be exposed.

  On the other hand, as shown in FIG. 15, a plate-like contact member 116 is fixed to the center portion in the longitudinal direction of the support member 38 of the LPH 20. As shown in FIG. 19, a protrusion 118 protruding inward is provided at the lower end of the plate surface of the contact member 116, and the protrusion 118 is located below the side plate member 102 at the retracted position of the LPH 20. Protruding to

  As described above, when the LHP 20 moves to the exposure position, as shown in FIG. 18, the protrusion 118 moves upward and comes into contact with the short side surface portion 102 </ b> A of the side plate member 102.

  As shown in FIGS. 20 and 21, as described in the first embodiment, a hemispherical projection 56 is provided inside the upright plate 54 </ b> A of the bracket 54. A plate spring 58 having a square cross-sectional shape is provided on the upright plate 54 </ b> A facing the plate.

  The leaf spring 58 urges the side surface portion 38 </ b> A of the support member 38 of the LPH 20 to press the support member 38 against the protrusion 56.

  Further, at the exposure position of the LPH 20, as shown in FIGS. 18 and 20, the leaf spring 58 urges the protrusion 118 of the abutting member 116 fixed to the LPH 20 to the short side surface portion 102A of the side plate member 102. ing.

  Thus, the distance between the support points is shortened, and the natural frequency of the LPH 20 in the orthogonal direction (Y direction shown in the figure) can be increased.

FIG. 2 is a perspective view showing a photosensitive drum, LPH, and the like employed in the image forming apparatus according to the first embodiment of the present invention. 1 is a front view showing a photosensitive drum, LPH, and the like employed in an image forming apparatus according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of the central portion in the LPH longitudinal direction, showing the photosensitive drum, the LPH, and the side plate member employed in the image forming apparatus according to the first embodiment of the present invention. 1 is a cross-sectional view of an end portion in the LPH longitudinal direction, showing a photosensitive drum, an LPH, and a side plate member employed in an image forming apparatus according to a first embodiment of the present invention. 1 is a perspective view showing an LPH employed in an image forming apparatus according to a first embodiment of the present invention. 1 is a schematic configuration diagram illustrating an image forming apparatus according to a first embodiment of the present invention. FIG. 5 is a perspective view showing a photosensitive drum, LPH, and the like employed in an image forming apparatus according to a second embodiment of the present invention. FIG. 6 is a cross-sectional view of a central portion in the LPH longitudinal direction, showing a photosensitive drum, an LPH, and a side plate member employed in an image forming apparatus according to a second embodiment of the present invention. FIG. 7 is a cross-sectional view of an end portion in the LPH longitudinal direction, showing a photosensitive drum, an LPH, and a side plate member employed in an image forming apparatus according to a second embodiment of the present invention. FIG. 6 is a perspective view showing a photosensitive drum, LPH, and the like employed in an image forming apparatus according to a third embodiment of the present invention. FIG. 5 is a cross-sectional view of a central portion in the LPH longitudinal direction, showing a photosensitive drum, an LPH, and a side plate member employed in an image forming apparatus according to a third embodiment of the present invention. FIG. 6 is a cross-sectional view of an end portion in the LPH longitudinal direction, showing a photosensitive drum, an LPH, and a side plate member employed in an image forming apparatus according to a third embodiment of the present invention. FIG. 7 is a cross-sectional view of a central portion in the LPH longitudinal direction, showing a photosensitive drum, an LPH, and a side plate member employed in an image forming apparatus according to a fourth embodiment of the present invention. FIG. 6 is a cross-sectional view of an end portion in the LPH longitudinal direction, showing a photosensitive drum, an LPH, and a side plate member employed in an image forming apparatus according to a fourth embodiment of the present invention. FIG. 10 is a perspective view showing a photosensitive drum, LPH, and the like employed in an image forming apparatus according to a fifth embodiment of the present invention. FIG. 10 is a front view showing a photosensitive drum, LPH, and the like employed in an image forming apparatus according to a fifth embodiment of the present invention, with the LPH moved to an exposure position. FIG. 10 is a front view showing a photosensitive drum, LPH, and the like employed in an image forming apparatus according to a fifth embodiment of the present invention, with the LPH moved to a retracted position. FIG. 10 is a cross-sectional view of a central portion in the LPH longitudinal direction showing a state where the LPH is moved to an exposure position, such as a photosensitive drum and LPH, which are employed in an image forming apparatus according to a fifth embodiment of the present invention. FIG. 10 is a cross-sectional view of a central portion in the longitudinal direction of LPH showing a state where LPH is moved to a retracted position, such as a photosensitive drum and LPH, employed in an image forming apparatus according to a fifth embodiment of the present invention. FIG. 10 is a cross-sectional view of an end portion in the LPH longitudinal direction showing a state where the LPH is moved to an exposure position, such as a photosensitive drum and LPH, which are employed in an image forming apparatus according to a fifth embodiment of the present invention. FIG. 10 is a cross-sectional view of an end portion in the LPH longitudinal direction showing a state where the LPH is moved to a retracted position, such as a photosensitive drum and LPH, which are employed in an image forming apparatus according to a fifth embodiment of the present invention.

Explanation of symbols

10 Image forming apparatus 16 Photosensitive drum 54 Bracket (frame member)
60 Coil spring (biasing member)
62 Contact member 64 Side plate member 64A Short side surface portion 70 Side plate member 70A Short side surface portion 72 Bracket (frame member)
76 Coil spring (biasing member)
78 Contact member 80 Side plate member 80A Short side surface portion 82 Contact member 82A First contact portion 82B Second contact portion 84 Bracket (frame member)
88 Coil spring (second biasing member)
90 Coil spring (first biasing member)
94 Contact member 96A Contact part (first contact part)
98A Contact part (second contact part)
102 Side plate member 102A Short side surface portion 116 Contact member

Claims (5)

A photosensitive drum on which a latent image is formed by light irradiation;
A detachable light emitting device that extends along the axial direction of the photoconductive drum and that is arranged with a plurality of light emitting elements that irradiate light onto the surface of the photoconductive drum and whose both ends are supported by a frame member;
A side plate member that is supported by the frame member, extends in the axial direction of the photosensitive drum, and has a rectangular cross-sectional shape having a short side and a long side in a direction perpendicular to the axial direction;
An abutting member provided in the light emitter and abutting against a short side surface portion forming a short side of a cross section of the side plate member;
A biasing member that biases the abutting member toward the short side surface portion;
An image forming apparatus comprising:   The image forming apparatus according to claim 1, wherein the side plate member is disposed so that the short side surface portion faces a focal direction of the light emitter.   The image forming apparatus according to claim 1, wherein the side plate member is disposed so that the short side surface portion is oriented in an orthogonal direction orthogonal to a focal direction of the light emitter. A first side plate member in which the short side surface portion faces the focal direction of the light emitter;
A second side plate member in which the short side surface portion is oriented in an orthogonal direction orthogonal to the focal direction of the light emitter;
A first abutting portion provided on the abutting member and abutting with a short side surface portion of the first side plate member;
A second abutting portion provided on the abutting member and abutting on a short side surface portion of the second side plate member;
A first urging member that urges the first abutting portion against the first side plate member;
A second urging member that urges the second abutting portion against the second side plate member;
The image forming apparatus according to claim 1, further comprising:   5. The image forming apparatus according to claim 1, wherein the contact member is provided in a central portion in a longitudinal direction of the light emitting device.

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