JP2009015060A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an image forming apparatus capable of suppressing vibration conducted to a light emitting unit. <P>SOLUTION: By bringing a positioning pin 31 into contact with a contact part (P2) between a bearing 50 or 52 and a supporting plate 90, an LPH 20 is positioned. When image formation is started, a developing device 22 is vibrated by vibration of a motor for driving a developing roller 24. The vibration generated in the developing device 22 is propagated to the bearings 50 and 52. When the positioning pin 31 comes into contact at a position (P1) separated from the contact part P2, deformation amount (amplitude) of the bearings 50 and 52 at the position P1 is large, so that the vibration is propagated to the positioning pin 31, and the LPH 20 is vibrated. However, in this invention, since the positioning pin 31 comes into contact with the contact part P2, the deformation amount (amplitude) of the bearings 50 and 52 at the position P2 becomes the smallest, and the vibration propagated to the positioning pin 31 is suppressed, and then the vibration of the LPH 20 is suppressed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus.

  In image forming apparatuses such as printers, copiers, and facsimiles, an LED print head (LPH) using LEDs as recording elements is used as a recording head for forming a latent image on a photoreceptor. The LPH is replaced according to the use frequency (for example, specified by the number of prints).

  In the image forming apparatus, each LED of the LPH is driven based on the image data to output light toward the photoconductor, and the light output by the Selfoc lens is imaged on the surface of the photoconductor to thereby form a photoconductor. In addition to performing exposure based on the image data, the photosensitive member is rotated (this rotational direction is referred to as “process direction”) to move the exposure position and form an image on the photosensitive member.

  In such an image forming apparatus using LPH, variations in the amount of output energy may cause uneven exposure energy distribution, which may appear on the image as a streak in the process direction. This is called banding and causes a reduction in image quality. Banding occurs when the LPH resonates due to vibration of a motor or the like that drives each part of the image forming apparatus.

  Here, as an example of the LPH positioning configuration, the LPH positioning pins are abutted against the recesses of brackets (including bearings) provided on the outer periphery of both ends of the photoconductor, thereby performing relative positioning of the LPH and the photoconductor surface. There are some (for example, patent documents 1 to 3).

Another example of the LPH positioning configuration is one in which a positioning member is provided between the photosensitive member, the LPH, and the developing device (see, for example, Patent Document 4).
Japanese Patent Laid-Open No. 11-065400 JP 2005-014357 A JP 2001-080156 A JP 2005-242119 A

  An object of the present invention is to obtain an image forming apparatus capable of suppressing vibration transmitted to a light emitter.

  According to a first aspect of the present invention, there is provided an image forming apparatus comprising: a photoconductor on which a latent image is formed by irradiation of light emitted from a light emitter; and a photoconductor that is attached to both end portions of the photoconductor to freely rotate the photoconductor. A bearing; a support member that supports the bearing; and a positioning portion that contacts the contact portion of the bearing supported by the support member through a hole formed in the support member and positions the light emitter. It is characterized by that.

  The image forming apparatus according to claim 2 of the present invention is characterized in that the support member supports a plurality of locations on the outer periphery of the bearing.

  In the image forming apparatus according to a third aspect of the present invention, a concave portion along the outer peripheral surface of the bearing is formed in the support portion of the support member that supports the bearing, and the hole penetrates the concave portion. It is characterized by that.

  The invention according to claim 1 can suppress the vibration transmitted to the light emitter as compared with the case where the present configuration is not provided.

  The invention of claim 2 can further suppress vibration transmitted to the light emitter.

  According to the invention of claim 3, the displacement of the contact portion between the bearing and the support member is suppressed, and the vibration transmitted to the light emitter can be suppressed.

  A first embodiment of an image forming apparatus of the present invention will be described with reference to the drawings.

  FIG. 1 shows a printer 10 as an image forming apparatus.

  The printer 10 is an endless belt-like intermediate transfer belt 14 that is stretched around a plurality of winding rollers 12 inside a casing 11 that constitutes a main body and conveyed in the direction of arrow A by driving a motor (not shown). Is arranged.

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

  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 photoconductor 16 that rotates counterclockwise by a driving unit including a motor and a gear (not shown).

  On the peripheral surface of each photoconductor 16, a charging roller 18 for uniformly charging the surface of the photoconductor 16 to a predetermined potential is disposed. The charging roller 18 is a conductive roller, and the circumferential surface thereof is in contact with the circumferential surface of the photoconductor 16, and is arranged so that the axial direction of the charging roller 18 coincides with the axial direction of the photoconductor 16. Yes.

  Further, an LED print head (LED light emitting diode) that uses an LED (light emitting diode) for forming an electrostatic latent image on the photoreceptor 16 as a light source on the peripheral surface downstream of the charging roller 18 in the rotation direction of each photoreceptor 16. LPH) 20 is provided. Hereinafter, the LED print head 20 is referred to as LPH 20.

  As shown in FIG. 2a, the LPH 20 includes a plurality of LEDs arrayed with LED chips 30 arranged in a line, and a plurality of LEDs for imaging the light output from the LEDs on the surface of the photoreceptor. And a SELFOC lens array 32 in which rod lenses are arranged.

  The LED array 28 is configured by arranging a plurality of LED chips 30 on a printed circuit board 28A on which a circuit for supplying various signals for controlling 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 this embodiment, the rotation axis direction of the photoconductor 16 is defined as the LPH longitudinal direction (X direction), and the direction intersecting the LPH longitudinal direction is defined as the process direction (Y direction). Here, the process direction corresponds to the rotation direction of the photoconductor 16 as described above.

  The LED chips 30 are arranged in the LPH longitudinal direction with the arrangement direction of each LED aligned with the LPH longitudinal direction, and the mounting positions in the process direction are alternately shifted by a predetermined pitch (staggered arrangement), and are attached to the printed circuit board 28A. It has been. By adopting the staggered arrangement as described above, the positions of the LED chips 30 adjacent to each other in the LPH longitudinal direction can be overlapped with each other in the LPH longitudinal direction, so that the interval between the LEDs does not vary.

  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 photoconductor 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 16.

  As shown in FIG. 2b, the LPH 20 has a pair of positioning pins 31 erected on the same side as the SELFOC lens array 32 from the upper surface of both end portions upward. The positioning pin 31 has a hemispherical upper end.

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

  On the other hand, as shown in FIG. 1, an electrostatic latent image formed on the photoconductor 16 is placed on a peripheral surface downstream of the LPH 20 in the rotation direction of each photoconductor 16 with a predetermined color (yellow / magenta / cyan / cyan). A developing device 22 is provided for developing with a black toner to form a toner image.

  The developing device 22 is attached inside the image forming unit 15.

  The developing unit 22 includes a cylindrical developing roller 24 that is disposed in proximity to the photosensitive member 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 transported to the surface of the photoconductor 16, and the toner is rubbed against the photoconductor 16 to develop the electrostatic latent image formed on the photoconductor 16. Is done.

  A transfer roller 25 for transferring the toner image on each photoconductor 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 photoconductor 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 photoreceptor 16. As a result, the transfer roller 25 transfers the toner on the photoconductor 16 onto the intermediate transfer belt 14.

  Here, the toner images of different colors formed by the image forming units 15 are respectively transferred to the intermediate transfer belt 14 so as to overlap each other on the belt surface of the intermediate transfer belt 14. 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 belt 14 is sent between the rollers 34A and 34B, taken out from the paper tray 36 provided at the bottom of the printer 10, and similarly between the rollers 34A and 34B. The image is transferred onto the conveyed paper 38.

  In addition, a fixing device 40 including a heating roller 40A and a pressure roller 40B is disposed on the conveyance path of the paper 38 to which the final toner image has been transferred. The sheet 38 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 38 is melted and pressed against the sheet 38 to be fixed. As a result, a desired image (color image) is formed on the paper 38. The paper 38 on which the image is formed is discharged out of the apparatus.

  On the other hand, a cleaner 42 that collects toner remaining on the intermediate transfer belt 14 without being transferred to the paper 38 by the transfer device 34 is disposed downstream of the transfer device 34 in the transport direction of the intermediate transfer belt 14. ing. 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.

  Next, the configuration of the image forming unit 15 will be described.

  As shown in FIGS. 3 and 5a, the photosensitive member 16 has a cylindrical shaft portion 46 protruding outward from both end faces. Bearings 48 and 50 are extrapolated from the end on one side, and bearings 52 and 54 and a drive gear 56 for rotational driving are extrapolated from the other end on the shaft 46.

  The bearings 48 and 54 and the drive gear 56 are restricted from moving in the axial direction by engaging a C-ring 58 with a groove (not shown) formed along the outer peripheral surface of the shaft 46.

  In addition, the bearings 50 and 52 are fitted into holes formed in the side wall of the resin casing 17 of the image forming unit 15, so that the photosensitive member 16 is rotatably supported. The driving gear 56 is meshed with a gear of a motor (not shown), and the photosensitive member 16 is rotated by driving the motor.

  The housing 17 is formed with an opening 76 for arranging the photosensitive member 16 and the above-described intermediate transfer belt 14 to face each other.

  Further, an opening 62 for attaching the LPH 20 from the outside is formed on the side wall of the housing 17. Further, a plate-like support wall 66 is erected upward from the upper surface of the bottom plate 64 of the housing 17. A spring 70 is attached to one side surface of the support wall 66 in a substantially horizontal direction, and a plate material 72 is fixed to the tip of the spring 70.

  A rectangular opening 68 is formed in the bottom plate 64 along the axial direction of the photoconductor 16 so as to correspond to the opening 62. A rectangular bottom cover 74 having a size substantially equal to that of the opening 68 is fitted into the opening 68 from the lower side of the housing 17.

  A spring 78 is attached to the upper surface of the bottom lid 74 in a substantially vertical direction, and a plate member 80 is fixed to the tip of the spring 78. A plate-like support wall 82 is erected from the upper surface of the bottom lid 74 upward. A hemispherical protrusion 82 </ b> A is formed on the upper side surface of the support wall 82.

  On the other hand, as shown in FIGS. 3a and 3b, the developing device 22 includes a housing 27 in which the developing roller 24 and a supply roller 25 for supplying toner to the developing roller 24 can be rotated by a bearing (not shown). Is provided. A driving gear and a motor (not shown) are attached to the end of the developing roller 24 so as to be driven to rotate.

  A rectangular opening 94 is formed in the side wall 93 of the housing 27 facing the photoconductor 16. A part of the outer peripheral surface of the developing roller 24 is exposed from the opening 94. Further, on both sides of the opening 94, substantially cylindrical positioning pins 96 project from the side wall 93 toward the photoconductor 16. The tip of the positioning pin 96 has a hemispherical shape.

  Here, before the LPH 20 is attached, the developing device 22 is placed on the support plate 19 provided inside the housing 17 of the image forming unit 15. At this time, both end portions of the developing device 22 in the longitudinal direction are in contact with side walls (not shown) arranged on the front side and the back side of the paper surface, so that the developing device 22 is positioned in the longitudinal direction. Further, the positioning pins 96 come into contact with the outer peripheral surfaces of the bearings 50 and 52, so that the developing device 22 is positioned with respect to the photosensitive member 16. The developing device 22 vibrates in the arrow X direction when the developing roller is driven by a motor.

  Next, the positioning mechanism of the LPH 20 will be described.

  As shown in FIGS. 4 and 5, a pair of high-rigidity side plates 84 (84 </ b> A and 84 </ b> B) are erected in the printer 10 so as to sandwich the image forming unit 15.

  In the side plates 84A and 84B, guide grooves 86 (86A and 86B) having a width larger than the outer diameter of the bearings 48 and 54 are formed. Engagement portions 88 (88A, 88B) are formed on the front end sides of the guide grooves 86A, 86B. Yes.

  Further, on the inner side surfaces of the side plates 84A and 84B, on the lower side of the engaging portion 88, high-rigidity support plates 90 (90A and 90B) are provided so as to project along the axial direction of the photoreceptor 16. The support plates 90A and 90B are formed with through holes 92 (92A and 92B) of a size that allows the positioning pins 31 of the LPH 20 to be inserted in the vertical direction.

  As shown in FIG. 4, in the image forming unit 15, the bottom cover 74 is removed, and the openings 62 and 68 are open. In this state, the bearings 48 and 54 are pushed inward along the guide grooves 86A and 86B.

  When the bearings 48 and 54 reach the tips of the guide grooves 86A and 86B, they are dropped and engaged with the engaging portions 88A and 88B. At this time, the bearings 50 and 52 are in contact with the upper surfaces of the support plates 90A and 90B.

  Subsequently, as shown in FIGS. 3 a and 4, the LPH 20 is inserted upward from the lower side of the opening 68 while being placed on the plate member 80. The plate material 72 is retracted to a position where it does not come into contact with the LPH 20.

  Subsequently, the LPH 20 is biased upward by the elastic force of the spring 78. Then, the tip of the positioning pin 31 of the LPH 20 is inserted into the through hole 92 of the support plate 90 and contacts the outer peripheral surface of the bearings 50 and 52, thereby positioning the LPH 20 in the focal direction.

  Subsequently, the plate member 72 contacts the side surface of the LPH 20 and urges the LPH 20 toward the support wall 82. The LPH 20 is positioned with respect to the process direction of the photoconductor 16 when the side surface comes into contact with the protrusion 82 </ b> A of the support wall 82.

  In this way, the distance between the peripheral surface of the photoconductor 16 and the LPH 20 becomes a predetermined distance. Along with the positioning of the LPH 20, the bottom lid 74 is fitted into the opening 68, and the bottom lid 74 is fixed to the image forming unit 15 by an engagement member or a slide member (not shown).

  Next, the operation of the first embodiment of the present invention will be described.

  As shown in FIG. 5 a, the LPH 20 and the developing device 22 are positioned with respect to the photoreceptor 16. When the main power supply of the printer 10 (see FIG. 1) is turned on and image formation is started, the developing roller 24 of the developing device 22 is driven by a motor. The developing unit 22 vibrates in the direction of the arrow X by driving the motor, and becomes a vibration source.

  The vibration generated in the developing device 22 propagates to the bearings 50 and 52 with which the positioning pins 96 of the developing device 22 are in contact.

  Here, as shown in FIG. 5b, the positioning pin 31 of the LPH 20 contacts the outer peripheral surface of the bearing 50, 52 at a position P1 away from the contact portion (on the contact line) between the bearing 50, 52 and the support plate 90. If so, the amount of deformation of the bearings 50 and 52 at the position P1, that is, the amplitude is large, so that the vibration propagates to the positioning pin 31 and the LPH 20 vibrates.

  However, in the present invention, the positioning pin 31 is in contact with the outer peripheral surface of the bearings 50 and 52 at a position P2 that is a contact portion between the bearings 50 and 52 and the support plate 90. For this reason, the deformation amount (amplitude) of the bearings 50 and 52 at the position P2 is the smallest, the vibration propagating to the positioning pin 31 is suppressed, and the vibration of the LPH 20 can be suppressed.

  By suppressing the vibration of the LPH 20, it is possible to irradiate light to a predetermined position on the surface of the photoconductor 16, and the density of the latent image becomes an appropriate state, thereby suppressing image banding.

  Next, a second embodiment of the image forming apparatus of the present invention will be described with reference to the drawings.

  Note that components that are basically the same as those in the first embodiment described above are given the same reference numerals as those in the first embodiment, and descriptions thereof are omitted.

  FIG. 6a shows a peripheral portion of the photoreceptor 16 in the printer 100 as the image forming apparatus. In this embodiment, the photoconductor 16 has a columnar shaft portion 110 that protrudes outward from both end surfaces.

  A bearing 50 is extrapolated to the shaft portion 110 from one end portion, and bearings 52 and 54 and a drive gear 56 for rotational driving are extrapolated from the other end portion. The bearings 50, 52, 54 and the drive gear 56 are fixed by a C ring 58.

  Further, side plates 102 </ b> A and 102 </ b> B to which the photosensitive member 16 is attached are erected inside the printer 100.

  A hole 108 into which the bearing 54 is fitted is formed in the side plate 102B. Further, support portions 104 (104A, 104B) are formed along the axial direction of the photoconductor 16 on the inner side surfaces of the side plates 102A, 102B and below the hole portion 108, respectively.

  As shown in FIG. 7, the support portions 104 </ b> A and 104 </ b> B have a concave cross-sectional shape in the axial direction of the photoconductor 16, and the interval between the inner walls is substantially equal to the diameter of the bearings 50 and 52. Yes. The bearings 50 and 52 are supported in contact with the support portions 104A and 104B at a plurality of locations by being fitted into the support portions 104A and 104B.

  The support portions 104A and 104B are formed with through holes 106 (106A and 106B) having a size that allows the positioning pins 31 of the LPH 20 to be inserted in the vertical direction. The through hole 106 is in a contact portion (on the contact line) between the bearings 50 and 52 and the support portion 104, and the positioning pin 31 of the LPH 20 is positioned on the contact line.

  On the other hand, a developing device 112 having the developing roller 24 described above is disposed above the photosensitive member 16. The developing device 112 has an opening (not shown), and a part of the outer peripheral surface of the developing roller 24 is exposed from the opening. Also, a substantially cylindrical positioning pin 113 for positioning the developing device 112 is provided on both sides of the opening.

  The developing device 112 is supported by being engaged with an engaging portion (not shown) provided in the printer 100, and the positioning pin 113 is fixed in the printer 100 by contacting the outer peripheral surface of the bearings 50 and 52. . The bearings 50 and 52 are also fixed to the support unit 104 by fixing the developing device 112.

  A bottom plate 114 is provided below the photoconductor 16 and the support portion 104. A spring 78 is attached to the upper surface of the bottom plate 114 in a substantially vertical direction, and a plate member 80 is fixed to the tip of the spring 78.

  A plate-like support plate 118 is provided in the vicinity of the plate member 80. A hemispherical protrusion 118 </ b> A is formed on the upper side surface of the support plate 118.

  A support plate 116 is provided on the side opposite to the support plate 118. A spring 70 is attached to one side surface of the support plate 116 in a substantially horizontal direction, and a plate material 72 is fixed to the tip of the spring 70.

  Here, the LPH 20 is placed on the plate member 80 in a state where the plate member 72 is retracted to a position where it does not come into contact with the LPH 20. The LPH 20 moves upward by the elastic force of the spring 78. Then, the tip of the positioning pin 31 of the LPH 20 is inserted into the through hole 106 of the support plate 104 and contacts the outer peripheral surface of the bearings 50 and 52, thereby positioning the LPH 20 in the focal direction.

  Subsequently, the plate member 72 contacts the side surface of the LPH 20 and urges the LPH 20 toward the support plate 118. The LPH 20 is positioned with respect to the process direction of the photoconductor 16 when the side surface comes into contact with the protrusion 118A of the support plate 118. In this way, the distance between the peripheral surface of the photoconductor 16 and the LPH 20 is a predetermined distance.

  Next, the operation of the second embodiment of the present invention will be described.

  As shown in FIGS. 6 and 7, the LPH 20 and the developing device 112 are positioned with respect to the photoreceptor 16. When the main power supply of the printer 100 is turned on and image formation is started, the developing roller 24 of the developing device 112 is driven by a motor. The developing device 112 vibrates in the direction of the arrow Z by driving the motor and becomes a vibration source.

  The vibration generated in the developing device 112 propagates to the bearings 50 and 52 with which the positioning pins 113 of the developing device 112 are in contact.

  Here, the positioning pin 31 of the LPH 20 is in contact with the outer peripheral surface of the bearings 50 and 52 at the contact portion (on the contact line) between the bearings 50 and 52 and the support portion 104. Since the deformation amount (amplitude) of the bearings 50 and 52 at the contact portion is the smallest, the vibration propagating to the positioning pin 31 is suppressed, and the vibration of the LPH 20 can be suppressed.

  In addition, since there are a plurality of contact points (three locations) between the bearings 50 and 52 and the support portion 104 where the deformation amount of the bearings 50 and 52 becomes the smallest, vibrations are further less likely to be transmitted to the positioning pins 31 of the LPH 20. .

  By suppressing the vibration of the LPH 20, it is possible to irradiate light to a predetermined position on the surface of the photoconductor 16, and the density of the latent image becomes an appropriate state, thereby suppressing image banding.

  As another embodiment, as shown in FIG. 8, an L-shaped support portion 120 in which a through hole 122 is formed may be used. Here, the positioning pin 113 of the developing device 112 is in contact with the bearings 50 and 52 at an angle of approximately 45 degrees and is biased toward the support portion 120, and the photosensitive member 16 is fixed. There are two contact points between the bearings 50 and 52 and the support part 120.

  By positioning the positioning pin 31 of the LPH 20 on the contact line between the support portion 120 and the bearings 50 and 52, the same effect as that obtained when the support portion 104 is used can be obtained.

  As another embodiment, as shown in FIG. 9, an annular bearing cover 123 in which a through hole 125 is formed may be used as a support portion. Here, the bearing cover 123 is attached to the side wall of the photoreceptor unit 121 having the photoreceptor 16, and the inner peripheral surface 124 of the bearing cover 123 and the outer peripheral surfaces of the bearings 50 and 52 are in contact (fitted). Thus, the bearings 50 and 52 are supported. The contact location between the bearings 50 and 52 and the bearing cover 123 is the entire outer periphery of the bearings 50 and 52 except the through hole 125.

  Since the positioning pin 31 of the LPH 20 is positioned on the contact line between the bearing cover 123 and the bearings 50 and 52, the same effect as that obtained when the support portion 104 is used can be obtained.

  Next, a third embodiment of the image forming apparatus of the present invention will be described with reference to the drawings.

  Note that components that are basically the same as those in the first embodiment described above are given the same reference numerals as those in the first embodiment, and descriptions thereof are omitted.

  10a and 10b show support plates 126 and 132 obtained by modifying a part of the support plate 90 (see FIG. 5) described in the first embodiment.

  The support plate 126 has a through hole 128, and an inclined surface 130 is formed below the through hole 128.

  On the other hand, the support plate 132 has a recess 138 formed above the through hole 134 along the axial direction of the photoreceptor 16 (see FIG. 5). The recess 138 has a shape along the outer peripheral surface of the bearings 50 and 52 (see FIG. 5). An inclined surface 136 is formed below the through hole 134. In the present embodiment, an example using the support plate 132 will be described.

  FIG. 10c shows the periphery of the photoreceptor 16 in the printer 10 described above.

  The photoconductor 16 is supported by the bearings 50 and 52 engaging with the recesses 138 of the support plate 132. Further, the positioning pin 31 of the LPH 20 is inserted into the through hole 134 and is in contact with the outer peripheral surfaces of the bearings 50 and 52 to position the LPH 20. Since the positioning pin 31 is guided to the through hole 134 by contacting the inclined surface 136, the positioning pin 31 can be easily inserted into the through hole 134.

  Next, the operation of the third embodiment of the present invention will be described.

  When the main power supply of the printer 10 is turned on and image formation is started, a developing device (not shown) vibrates. The vibration generated in the developing device propagates to the bearings 50 and 52.

  Here, the positioning pin 31 of the LPH 20 is in contact with the outer peripheral surface of the bearings 50 and 52 at the contact portion (on the contact line) between the bearings 50 and 52 and the support plate 132. Since the deformation amount (amplitude) of the bearings 50 and 52 at the contact portion is the smallest, the vibration propagating to the positioning pin 31 is suppressed, and the vibration of the LPH 20 can be suppressed.

  By suppressing the vibration of the LPH 20, it is possible to irradiate light to a predetermined position on the surface of the photoconductor 16, and the density of the latent image becomes an appropriate state, thereby suppressing image banding.

  Further, since the bearings 50 and 52 are engaged with the recesses 138 of the support plate 132, the displacement of the contact portion (contact line) between the bearings 50 and 52 and the support plate 132 is suppressed, so that the positioning pin 31 of the LPH 20 It is possible to prevent the contact position from deviating from the contact line and increase in vibration.

  In addition, this invention is not limited to said embodiment.

  The printer 10 may use a liquid developer as well as a dry electrophotographic system using a solid developer.

  The positioning pin 31 is not limited to a hemispherical tip, but may be an acute angle or flat.

  The bearings 48, 50, 52, and 54 may have different outer diameters as long as the inner diameter is the same.

  A concave portion may be formed in the support plate 90, the support portion 104, and the support portion 120 to be engaged with the bearing.

1 is an overall view of a printer according to a first embodiment of the present invention. It is the schematic which shows the structure of the LED print head which concerns on 1st Embodiment of this invention. (A) It is sectional drawing of the image forming unit which concerns on 1st Embodiment of this invention. (B) It is a perspective view of the developing device concerning a 1st embodiment of the present invention. It is explanatory drawing which shows the attachment state of the photoconductor which concerns on 1st Embodiment of this invention. (A) It is sectional drawing of the image forming unit which concerns on 1st Embodiment of this invention. (B) It is the schematic diagram which showed the propagation state of the vibration in the bearing which concerns on 1st Embodiment of this invention. It is sectional drawing of the image forming unit which concerns on 2nd Embodiment of this invention. (A) It is sectional drawing of the image forming unit which concerns on 2nd Embodiment of this invention. (B) It is a perspective view of the support part which concerns on 2nd Embodiment of this invention. It is sectional drawing of the other Example of the image forming unit which concerns on 2nd Embodiment of this invention. (B) It is a perspective view of the support part in the other Example of 2nd Embodiment of this invention. It is sectional drawing of the other Example of the image forming unit which concerns on 2nd Embodiment of this invention. It is the perspective view of the support plate which concerns on 3rd Embodiment of this invention, and sectional drawing of an image forming unit.

Explanation of symbols

10 Printer (image forming device)
16 Photoconductor (Photoconductor)
20 LPH (light emitter)
31 Positioning pin (positioning part)
32 SELFOC lens array (light emitting part)
50 Bearing (Bearing)
52 Bearing
90 Support plate (support member)
92 Through hole (hole)
100 printer (image forming apparatus)
104 Support (support member)
106 Through hole (hole)
120 Supporting part (supporting member)
122 Through hole (hole)
123 Bearing cover (support member)
125 Through hole (hole)
126 Support plate (support member)
128 Through hole (hole)
132 Support plate (support member)
134 Through hole (hole)
138 Concavity (concave)

Claims (3)

A photoreceptor on which a latent image is formed by irradiation of light emitted from a light emitter;
Bearings attached to both ends of the photoconductor to make the photoconductor rotatable,
A support member for supporting the bearing;
A positioning part for contacting the contact part of the bearing supported by the support member through a hole formed in the support member and positioning the light emitter;
An image forming apparatus comprising:   The image forming apparatus according to claim 1, wherein the support member supports a plurality of locations on an outer periphery of the bearing. The support portion of the support member that supports the bearing is formed with a recess along the outer peripheral surface of the bearing, and the hole penetrates the recess. The image forming apparatus described.

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