JP2015000549A - Light irradiation device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress vibration of an irradiation part in a secondary scanning direction and an irradiation direction.SOLUTION: A light irradiation device includes: an irradiation part that irradiates an irradiated surface with light, primary-scans the light in a primary scanning direction, and has a rigidity higher in the light irradiation direction than in a secondary scanning direction; a first support part for supporting one end portion and the another end portion of the irradiation part in the primary scanning direction, in the irradiation direction; and a second support part for supporting the irradiation part in the secondary scanning direction, between the first support part at the one end portion and the first support part at the another end portion.

Description

  The present invention relates to a light irradiation device and an image forming apparatus.

  In Patent Document 1, an electrostatic latent image carrier 21 having a positioning base member 21b in a non-image region at both axial ends, and a substantially box body having a contact member 23p that contacts each of the positioning base member 21b. The write head 23L formed in a shape, the movable support member 23M formed to be movable with respect to the write head 23L, the write head 23L, and the movable support member 23M And a vibration suppressing means for suppressing the vibration of the writing head 23L by changing the natural frequency fn of the structure formed by the above-described method so as to avoid resonance with the excitation frequency due to disturbance. .

JP 2006-195129 A

  An object of the present invention is to suppress vibration in the sub-scanning direction and the irradiation direction of the irradiation unit.

  The invention according to claim 1 irradiates the irradiated surface with light and main-scans the light in the main scanning direction, and has a higher rigidity in the irradiation direction of the light than in the sub-scanning direction, and the irradiation unit The sub-scanning between the first support part that supports the one end part and the other end part in the main scanning direction in the irradiation direction, and the first support part in the one end part and the first support part in the other end part. A second support part that supports the irradiation part in a direction.

  According to a second aspect of the present invention, the irradiation unit includes a plurality of elements that irradiate light to the irradiated surface along the main scanning direction, and the second support unit includes the elements in the main scanning direction. The irradiation unit is supported in the region.

  A third aspect of the invention includes an image holding body and the light irradiation device according to the first or second aspect, wherein a light is applied to the surface of the image holding body as the irradiated surface to form a latent image. .

  According to the configuration of the first aspect of the present invention, the vibration in the sub-scanning direction and the irradiation direction of the irradiation unit can be suppressed as compared with the case where the irradiation unit and the second support unit in the present configuration are not provided.

  According to the configuration of the second aspect of the present invention, it is possible to suppress vibration of the irradiation unit in the sub-scanning direction, compared to the case where the second support unit is disposed outside the region where the elements are disposed in the main scanning direction.

  According to the configuration of the third aspect of the present invention, it is possible to suppress image defects caused by vibration in the sub-scanning direction and the irradiation direction of the irradiation unit.

1 is a schematic diagram illustrating a configuration of an image forming apparatus according to an exemplary embodiment. It is a schematic sectional drawing which shows the structure of the print head which concerns on this embodiment. It is a sectional side view which shows the support structure of the print head which concerns on this embodiment. It is a front sectional view showing a support structure of a print head according to the present embodiment. FIG. 4 is a diagram illustrating a state where the photoconductor module is detached from the image forming apparatus main body in FIG. 3. FIG. 5 is a diagram illustrating a state where the photoconductor module is detached from the image forming apparatus main body. It is a sectional side view which shows the support structure of the print head which concerns on a modification. It is a sectional side view which shows the support structure of the print head which concerns on a modification.

  Below, an example of an embodiment concerning the present invention is described based on a drawing.

(Configuration of image forming apparatus 10)
First, the configuration of the image forming apparatus 10 according to the present embodiment will be described. FIG. 1 is a schematic diagram illustrating a configuration of an image forming apparatus 10 according to the present embodiment.

  As shown in FIG. 1, the image forming apparatus 10 includes an image forming apparatus main body (apparatus housing) 11 in which each component is housed. Inside the image forming apparatus main body 11, a recording medium accommodating unit 12 that accommodates a recording medium P such as paper, an image forming unit 14 that forms an image on the recording medium P, and the recording medium accommodating unit 12 to the image forming unit. 14, a transport unit 16 that transports the recording medium P to 14, and a control unit 20 that controls the operation of each unit of the image forming apparatus 10. In addition, a recording medium discharge unit 18 for discharging the recording medium P on which an image is formed by the image forming unit 14 is provided on the upper portion of the image forming apparatus main body 11.

  The image forming unit 14 includes image forming units 22Y, 22M, 22C, and 22K (hereinafter referred to as 22Y to 22K) that form toner images of colors of yellow (Y), magenta (M), cyan (C), and black (K). An intermediate transfer belt 24 to which the toner images formed by the image forming units 22Y to 22K are transferred, and a first transfer member for transferring the toner images formed by the image forming units 22Y to 22K to the intermediate transfer belt 24 And a second transfer roll 28 as a second transfer member for transferring the toner image transferred to the intermediate transfer belt 24 by the first transfer roll 26 from the intermediate transfer belt 24 to the recording medium P. A fixing device 30 for fixing the toner image transferred from the intermediate transfer belt 24 to the recording medium P by the second transfer roll 28 to the recording medium P; It is equipped with a.

  The image forming units 22Y to 22K are arranged side by side along a substantially horizontal direction. Each of the image forming units 22Y to 22K has a photoreceptor 32 (an example of an image carrier) that rotates in one direction (the direction of arrow A in FIG. 1).

  Around each photoconductor 32, the charging device 34 for charging the photoconductor 32 and the photoconductor 32 charged by the charging device 34 are exposed in order from the upstream side in the rotation direction of the photoconductor 32, and the photoconductor 32 is electrostatically charged. An exposure device 59 (an example of a light irradiation device) that forms a latent image, a developing device 38 that develops the electrostatic latent image formed on the photoreceptor 32 by the exposure device 59, and a transfer of the toner image to the intermediate transfer belt 24 And a removal device 40 for removing the developer remaining on the photoreceptor 32 later.

  The exposure device 59 is disposed below the photoconductor 32 and includes a print head 60 (an example of an irradiation unit) and a support structure 70 (see FIG. 3) that supports the print head 60. The print head 60 irradiates the surface of the photosensitive member 32 (an example of the irradiated surface) from below with exposure light based on the image information sent from the control unit 20 to form an electrostatic latent image on the photosensitive member 32. It comes to form. Examples of the image information sent from the control unit 20 include image information generated by an external device and acquired by the control unit 20 from the external device, and image information generated by reading an image such as a document in the image forming apparatus 10. and so on. The specific configuration of the print head 60 and the support structure 70 of the print head 60 will be described later. In FIG. 2, the exposure light from the print head 60 is indicated by a symbol L.

  In the present embodiment, in each of the image forming units 22Y to 22K, the photoconductor 32, the charging device 34, and the removal device 40 are configured as an integrated photoconductor module 21 (see FIG. 3). As shown in FIG. 3, the housing 23 of the photoconductor module 21 includes support frames 23 </ b> A and 23 </ b> B that respectively support one axial end and the other axial end of the photoconductor 32, and an axial direction of the photoconductor 32. And a long frame 23C (see FIG. 4) provided on the support frame 23B from the support frame 23A.

  Further, the photoconductor module 21 is configured to be detachable in the axial direction of the photoconductor 32 with respect to the image forming apparatus main body 11 and is exchanged according to the life of the photoconductor 32 or the like. Note that the photoconductor module 21 may be configured to include only the photoconductor 32 without including the charging device 34 and the removal device 40, and the developing device 38 is further integrated in addition to the charging device 34 and the removal device 40. The configuration described above may be adopted. That is, the photoreceptor module 21 only needs to include at least the photoreceptor 32. However, in the present embodiment, it is assumed that the photoreceptor module 21 and the print head 60 are configured separately.

  As shown in FIG. 1, the intermediate transfer belt 24 is formed in an annular shape and is disposed above the image forming units 22 </ b> Y to 22 </ b> K. Winding rolls 42, 43, 44, 45 around which the intermediate transfer belt 24 is wound are provided on the inner peripheral side of the intermediate transfer belt 24. For example, when the winding roll 45 is driven to rotate, the intermediate transfer belt 24 is circulated (rotated) in one direction (in the direction of arrow B in FIG. 1) while being in contact with the photoreceptor 32. The winding roll 42 is an opposing roll that faces the second transfer roll 28 with the intermediate transfer belt 24 interposed therebetween.

  Further, on the outer peripheral side of the intermediate transfer belt 24, a removing device 25 that contacts the outer peripheral surface of the intermediate transfer belt 24 and removes the developer remaining on the intermediate transfer belt 24 after the transfer of the toner image onto the recording medium P. Is provided opposite to the winding roll 45 with the intermediate transfer belt 24 interposed therebetween.

  The first transfer roll 26 faces the photoconductor 32 with the intermediate transfer belt 24 interposed therebetween. A space between the first transfer roll 26 and the photoconductor 32 is a first transfer position where the toner image formed on the photoconductor 32 is transferred to the intermediate transfer belt 24.

  The second transfer roll 28 faces the winding roll 42 with the intermediate transfer belt 24 interposed therebetween. A space between the second transfer roll 28 and the winding roll 42 is a second transfer position T2 where the toner image transferred to the intermediate transfer belt 24 is transferred to the recording medium P.

  The transport unit 16 is disposed along the transport path 48, a feed roll 46 that feeds the recording medium P accommodated in the recording medium container 12, a transport path 48 that transports the recording medium P sent to the transport roll 46, and the transport path 48. And a plurality of transport rolls 50 for transporting the recording medium P sent out by the feed roll 46 to the second transfer position T2.

  The fixing device 30 fixes the toner image transferred at the second transfer position T2 to the recording medium P conveyed from the second transfer position T2. A discharge roll 52 that discharges the recording medium P on which the toner image is fixed to the recording medium discharge unit 18 is provided downstream of the fixing device 30 in the transport direction.

  Next, an image forming operation for forming an image on the recording medium P in the image forming apparatus 10 will be described.

  In the image forming apparatus 10, the recording medium P sent out from the recording medium container 12 by the sending roll 46 is sent to the second transfer position T <b> 2 by the plurality of transport rolls 50.

  On the other hand, in the image forming units 22 </ b> Y to 22 </ b> K, the photoconductor 32 charged by the charging device 34 is exposed by the print head 60 to form an electrostatic latent image on the photoconductor 32. The electrostatic latent image is developed by the developing device 38 to form a toner image on the photoreceptor 32. The color toner images formed by the image forming units 22Y to 22K are superimposed on the intermediate transfer belt 24 at the first transfer position to form a color image. Then, the color image formed on the intermediate transfer belt 24 is transferred to the recording medium P at the second transfer position T2.

  The recording medium P to which the toner image has been transferred is conveyed to the fixing device 30, and the transferred toner image is fixed by the fixing device 30. The recording medium P on which the toner image is fixed is discharged to the recording medium discharge unit 18 by the discharge roll 52. As described above, a series of image forming operations are performed.

(Configuration of print head 60)
Next, the configuration of the print head 60 will be described. FIG. 2 is a schematic cross-sectional view showing the configuration of the print head 60. The arrow Z direction in the figure indicates the light irradiation direction in the print head 60, the arrow X direction in the figure indicates the main scanning direction (the axial direction of the photoconductor 32), and the arrow Y direction in the figure indicates The sub-scanning direction is shown.

  As shown in FIG. 2, the print head 60 includes an LED array 62, a circuit board 64 on which the LED array 62 is mounted on one surface (upper surface in FIG. 2) 64A, a lens array 66, and a circuit board 64. A housing 63 as a support for supporting the other surface (the lower surface in FIG. 2) and a holder 68 for supporting the lens array 66 are provided.

  The LED array 62 is configured by arranging a plurality of LED elements 62A (light emitting diodes) as light emitting elements along the X direction. Specifically, the plurality of LED elements 62A are arranged in a zigzag pattern along the X direction, for example.

  The circuit board 64 has a drive circuit (not shown) for driving the LED array 62. This drive circuit (not shown) and the LED array 62 are electrically connected, and the LED array 62 emits light by a drive signal from the drive circuit (not shown).

  The lens array 66 includes a plurality of rod lenses 66A that form an image of light emitted from the LED array 62 on the photoconductor 32 along the X direction. Specifically, the rod lenses 66A are arranged in a staggered manner along the X direction, for example, corresponding to the arrangement of the LED elements 62A.

  The housing 63 has a length along the X direction, and is configured by a block (or a plate-like member) formed of a resin material or a metal material. Further, the housing 63 has, for example, a rectangular shape in which the Z direction is long and the Y direction is short as viewed in the X direction.

  The holder 68 supports the lens array 66 so that the LED array 62 and the lens array 66 face each other. Specifically, the holder 68 has a lower part joined to the housing 63 and an upper part joined to the lens array 66. The holder 68 forms a sealed space surrounded by the inner wall, the circuit board 64, and the lens array 66, and dust is prevented from entering the space from the outside. Further, guide grooves 69 for guiding a cleaning member 67 (see FIG. 1) for cleaning the surface of the lens array 66 are formed on both side surfaces of the holder 68.

  In the print head 60 of the present embodiment, the plurality of LED elements 62A arranged along the X direction emit light, and the light emitted from the LED array 62 is imaged on the photoreceptor 32 by the rod lens 66A. Thus, the light is main scanned in the X direction (main scanning direction).

  Here, in the present embodiment, the print head 60 has higher rigidity (bending rigidity) in the Z direction (light irradiation direction) than in the Y direction (sub-scanning direction). That is, the primary natural frequency in the print head 60 is higher in the Z direction than the Y direction (high frequency).

  Here, the rigidity is the rigidity of the print head 60 alone, for example, the rigidity measured in a state where the print head 60 is constrained at both ends in the longitudinal direction of the print head 60 (for example, support positions A1 and A2 described later). . That is, at least the rigidity in a state where the support by the Y-direction datum portion 76 and the coil spring 86 described later is not made.

  The print head 60 has a shape having a length in the Z direction as viewed in the X direction, but is not limited thereto. The rigidity of the print head 60 varies depending on the material and the like, and is not limited only by the shape (cross-sectional shape).

(Support structure 70 of print head 60)
Next, the support structure 70 that supports the print head 60 will be described.

  As shown in FIG. 3, the support structure 70 includes a support mechanism 71 provided in the photoreceptor module 21 and a support mechanism 80 configured separately from the photoreceptor module 21. The support mechanism 71 includes a Z-direction datum unit 72 that serves as a reference for positioning (positioning) in the Z direction with respect to the print head 60, and an X-direction datum unit 74 that serves as a reference for positioning (positioning) in the X direction with respect to the print head 60. And a Y-direction datum unit 76 (see FIG. 4) that serves as a reference for positioning (positioning) in the Y-direction with respect to the print head 60.

  Specifically, the Z-direction datum unit 72, the X-direction datum unit 74, and the Y-direction datum unit 76 are provided in the housing 23 of the photoreceptor module 21. Accordingly, the Z-direction datum unit 72, the X-direction datum unit 74, and the Y-direction datum unit 76 are attached to and detached from the image forming apparatus main body 11 along the X direction integrally with the photoreceptor module 21. Yes. The direction of arrow C in the figure indicates the direction in which the photoreceptor module 21 is removed from the image forming apparatus main body 11.

  The Z-direction datum unit 72, the X-direction datum unit 74, and the Y-direction datum unit 76 have reference planes (datum planes) 72M, 74M, and 76M that serve as references for positioning (positioning), respectively.

  The Z-direction datum unit 72 is composed of two Z-direction datum units 72A and 72B. Specifically, the Z-direction datum portions 72A and 72B are provided on the support frames 23A and 23B so as to extend from the support frames 23A and 23B of the photoreceptor module 21 to the print head 60 side (lower side in FIG. 3). ing. The reference surfaces 72M of the Z-direction datum portions 72A and 72B are opposed to the upper surfaces of one end portion and the other end portion in the longitudinal direction of the print head 60, respectively, in the mounted state of the photoconductor module 21 with respect to the image forming apparatus main body 11. (To contact).

  One X-direction datum unit 74 is configured. The X-direction datum unit 74 is provided on the support frame 23A so as to extend from the support frame 23A of the photoreceptor module 21 to the print head 60 side (lower side in FIG. 3). Then, the reference surface 74M of the X-direction datum unit 74 faces the end surface in the X direction (the end surface on the right side in FIG. 3A) of the print head 60 when the photosensitive module 21 is mounted on the image forming apparatus main body 11. (Contact).

  Although only one Y-direction datum unit 76 is illustrated in FIG. 4, for example, there are two Y-direction datum units 76. The two Y-direction datum portions 76 are provided at both ends in the longitudinal direction of the long frame 23C so as to extend from the long frame 23C of the photoreceptor module 21 to the print head 60 side (lower side in FIG. 4). Yes. The reference surfaces 76M of the two Y-direction datum portions 76 are respectively at both ends in the longitudinal direction of the print head 60 and on the Y-direction side of the print head 60 when the photosensitive module 21 is mounted on the image forming apparatus main body 11. It faces (contacts) the side surface (the left side surface in FIG. 4).

  As shown in FIG. 3, the support mechanism 80 includes a support frame 90, a coil spring 82 (an example of a first support portion) as a biasing member that biases the print head 60 toward the Z-direction datum portion 72, and A coil spring 84 as an urging member that urges the print head 60 toward the X direction datum part 74 and a coil spring 86 (second support) as an urging member that urges the print head 60 toward the Y direction datum part 76. An example).

  The support frame 90 includes a bottom wall 92 disposed below the print head 60, side walls 94 and 96 disposed on both sides in the longitudinal direction (X direction) of the print head 60, and the short side of the print head 60. And side walls 97 and 99 (see FIG. 4) arranged on both sides in the direction (Y direction). That is, the support frame 90 is configured in a box shape with a bottom that is open at the top.

  The bottom wall 92 is formed in a plate shape having a length along the longitudinal direction of the print head 60. On one end side and the other end side in the longitudinal direction (X direction) of the bottom wall 92, as shown in FIGS. 5 and 6, a stopper 93 as a restricting portion that restricts the upward movement of the print head 60 is provided. It is provided so as to extend upward. As shown in FIG. 6, the stopper 93 is formed in an inverted L shape when viewed in the X direction. The stopper 93 hits the upper surface on one end side and the other end side in the longitudinal direction of the print head 60 in a state where the photoconductor module 21 is removed from the image forming apparatus main body 11 (the state shown in FIGS. 5 and 6). As a result, the upward movement of the print head 60 is restricted.

  As shown in FIG. 3, the side wall 94 has one end in the longitudinal direction of the bottom wall 92 (in FIG. 3) so as to have a gap with respect to the side of the print head 60 in the one end in the longitudinal direction (the right side in FIG. 3). It stands up from the right end side). The side wall 96 extends upward from the other end in the longitudinal direction of the bottom wall 92 (the left end in FIG. 3) so as to have a gap with respect to the side surface on the other end in the longitudinal direction of the print head 60 (the left side in FIG. 3). It is erected.

  Further, the side wall 94 is lower than the side wall 96, and the side surface (right side surface in FIG. 3) on one end side in the longitudinal direction of the print head 60 is exposed (covered) on the outside (right side in FIG. 3). Not) In the space above the side wall 94, the X-direction datum unit 74 is in contact with the end surface of the print head 60 in the X direction. That is, the space above the side wall 94 is a space in which the X-direction datum unit 74 in a state of being in contact with the end surface of the print head 60 in the X direction is arranged.

  Further, as shown in FIG. 5, the side wall 94 functions as a restricting portion that restricts the movement of the print head 60 in the X direction (the right side in FIG. 5). That is, the side wall 94 is a side surface on the one end side in the longitudinal direction of the print head 60 (the right side surface in FIG. 5) in a state where the photoconductor module 21 is removed from the image forming apparatus main body 11 (the state shown in FIGS. 5 and 6). In this way, the movement of the print head 60 in the X direction is restricted.

  As shown in FIG. 4, the side wall 97 has one end side in the short direction of the bottom wall 92 so as to have a gap with respect to the side surface on the one end side in the short direction of the print head 60 (the right side surface in FIG. 4). It is erected upward from the right end side in FIG.

  The side wall 99 has the other end side in the short direction of the bottom wall 92 (the left end side in FIG. 4) so as to have a gap with respect to the side surface on the other side in the short side direction of the print head 60 (the left side surface in FIG. 4). It stands up from the top.

  As shown in FIG. 6, the side wall 99 is provided with a stopper 98 as a restricting portion that restricts the movement of the print head 60 to the side (left side in FIG. 6). The stopper 98 protrudes from the side wall 99 to the print head 60 side (right side in FIG. 6). The stopper 98 is a side surface on the one end side in the short side direction of the print head 60 (the left side in FIG. 6) when the photosensitive module 21 is removed from the image forming apparatus main body 11 (the state shown in FIGS. 5 and 6). The movement of the print head 60 in the lateral direction is restricted.

  As shown in FIG. 4, the coil spring 82 includes three coil springs 82A, 82B, and 82C. As shown in FIG. 3, the coil spring 82 </ b> B has one axial end fixed to the upper surface of one end in the longitudinal direction of the bottom wall 92 (the right end in FIG. 3) so as to expand and contract in the vertical direction. The other axial end of the coil spring 82B is in contact with the lower surface of the longitudinal one end of the print head 60.

  As shown in FIG. 3, the coil springs 82 </ b> A and 82 </ b> C have one axial end fixed to the upper surface on the other end in the longitudinal direction of the bottom wall 92 (left end in FIG. 3). Yes. Further, as shown in FIG. 4, the coil springs 82 </ b> A and 82 </ b> C are arranged along the short direction (Y direction) of the bottom wall 92 so as to sandwich the coil spring 82 </ b> B when viewed in the X direction. . The other axial ends of the coil springs 82A and 82C are in contact with the lower surface of the other longitudinal end of the print head 60.

  As described above, when the coil springs 82A, 82B, and 82C are in contact with the lower surface of the print head 60, the coil springs 82A, 82B, and 82C push the lower surface of the print head 60 upward, thereby causing the print head 60 to move in the Z-direction datum portion. It is energizing towards 72. The urging force causes the upper surface of the print head 60 to contact the reference surface 72M of the Z-direction datum unit 72, so that the print head 60 is positioned in the Z direction.

  As shown in FIG. 3, the coil spring 84 includes two coil springs 84 </ b> A and 84 </ b> B. The coil springs 84A and 84B have one end in the axial direction fixed to the side surface (the right side surface in FIG. 3) of the side wall 96 facing the print head 60 so as to expand and contract in the X direction. Specifically, as shown in FIG. 4, the coil spring 84 </ b> B is arranged on the upper side of the coil spring 84 </ b> A and on the side wall 99 side (left side in FIG. 4). Further, the other axial end portions of the coil springs 84A and 84B are in contact with the side surface (the left side surface in FIG. 3) on the other end side in the longitudinal direction of the print head 60, as shown in FIG.

  Accordingly, the coil springs 84A and 84B push the left side surface of the print head 60 in FIG. 3 to the right side to urge the print head 60 toward the X direction datum part 74. The urging force causes the right side surface of the print head 60 to come into contact with the reference surface 74M of the X-direction datum unit 74, so that the print head 60 is positioned in the X direction.

  As shown in FIG. 3, the coil spring 86 is composed of one. As shown in FIG. 4, the coil spring 86 has one end in the axial direction fixed to the side surface (the left side surface in FIG. 4) of the side wall 97 facing the print head 60 so as to expand and contract in the Y direction. . The other end of the coil spring 86 in the axial direction is in contact with the side surface of the print head 60 on the one end side in the short side direction (the right side surface in FIG. 4).

  Accordingly, the coil spring 86 pushes the right side surface of the print head 60 in FIG. 4 to the left side and biases the print head 60 toward the Y direction datum unit 76. The urging force causes the left side surface of the print head 60 to come into contact with the reference surface 76M of the Y-direction datum unit 76, so that the print head 60 is positioned in the Y direction.

  Here, in the present embodiment, the coil spring 86 is in contact with the center in the longitudinal direction of the print head 60 as shown in FIG. That is, when viewed in the Y direction, the coil spring 86 is located between the support position A1 by the coil spring 82B and the Z direction datum part 72A and the support position A2 by the coil springs 82A and 82C and the Z direction datum part 72B. Is supported in the Y direction. More specifically, the coil spring 86 supports the print head 60 in the arrangement region R in which the LED array 62 (LED element 62A) in the X direction is arranged in the Y direction view.

  In the state where the support is provided by the Y-direction datum part 76 and the coil spring 86, the difference between the rigidity in the Y direction (sub-scanning direction) and the rigidity in the Z direction (light irradiation direction) of the print head 60 is It is smaller than the case of the head 60 alone, or the rigidity is higher in the Y direction than in the Z direction. The primary natural frequency in a vibration system constituted by the print head 60 and the support structure 70 (coil springs 82, 84, 86) is the difference between the frequency in the Y-direction vibration and the frequency in the Z-direction vibration. It is smaller than that in the case of the head 60 alone or higher in the Y direction than the Z direction (high frequency).

  Thus, in this embodiment, three coil springs 82, 84, and 86 are provided in the Z direction, two in the X direction, and one in the Y direction. That is, the number of coil springs 82, 84, 86 is different in the Z direction, the X direction, and the Y direction. Further, the number of coil springs 82 and 86 is larger in the Z direction where the rigidity of the print head 60 itself is higher than in the Y direction where the rigidity is low. The configuration in which the number of coil springs is larger in the Z direction where the rigidity of the print head 60 itself is higher than in the Y direction where the rigidity is low, for example, is four coil springs 82 in the Z direction and two coil springs 86 in the Y direction. It may be one.

(Operation according to this embodiment)
Next, the operation according to this embodiment will be described.

  In the configuration of the present embodiment, the print head 60 is pressed upward against the stopper 93 by the coil spring 82 in a state where the photosensitive module 21 is removed from the image forming apparatus main body 11 (the state shown in FIGS. 5 and 6). It has been. The print head 60 is pressed against the side wall 94 in the X direction by a coil spring 84. Further, the print head 60 is pressed against the stopper 98 by the coil spring 86 in the Y direction.

  When the photoreceptor module 21 is mounted on the image forming apparatus main body 11 (see FIGS. 3 and 4), the Z-direction datum unit 72 pushes the print head 60 downward against the urging force of the coil spring 82. Further, the X-direction datum unit 74 pushes the print head 60 in the X direction (left side in FIG. 3) against the urging force of the coil spring 84. Further, the Y-direction datum unit 76 pushes the print head 60 in the Y direction (right side in FIG. 4) against the urging force of the coil spring 86.

  When the photoconductor module 21 is mounted on the image forming apparatus main body 11, the reference surface 72M of the Z direction datum unit 72, the reference surface 74M of the X direction datum unit 74, and the reference surface 76M of the Y direction datum unit 76, respectively. However, it is in a state where it hits the print head 60. Thereby, the print head 60 is positioned in the Z direction, the X direction, and the Y direction.

  Here, the rigidity of the print head 60 alone is higher in the Z direction than in the Y direction. Therefore, when vibration in the Z direction is input to the print head 60 positioned in the Z direction, X direction, and Y direction, the rigidity of the print head 60 alone is higher in the Y direction than in the Z direction. Compared to the comparative example, the vibration in the Z direction is suppressed to a small level. That is, since the vibration in the Z direction becomes a high frequency, the pitch of banding (stripe density unevenness) is small, and image quality defects are suppressed.

  Further, the print head 60 is supported at the center in the longitudinal direction (X direction) by a Y direction datum part 76 and a coil spring 86. For this reason, even when vibration in the Y direction is input to the print head 60 positioned in the Z direction, the X direction, and the Y direction, in the case of the comparative example that supports outside the support position A1 and the support position A2. In comparison, the vibration in the Y direction is suppressed to a small level. That is, since the vibration in the Y direction becomes a high frequency, the pitch of banding (stripe density unevenness) is small, and image quality defects are suppressed.

  As described above, in the present embodiment, vibration in the Z direction is suppressed by the rigidity of the print head 60 itself, and the print head 60 and the support structure 70 (coil springs 82 and 84 are supported by the Y direction datum unit 76 and the coil spring 86. 86), the vibration in the Y direction is suppressed.

  Here, since the Y direction is the sub-scanning direction along the image plane, the vibration in the Y direction is more sensitive to the occurrence of banding than the vibration in the Z direction. That is, the vibration in the Y direction is more likely to appear in the image as banding than the vibration in the Z direction.

  As described above, the vibration in the Y direction is not the rigidity of the print head 60 itself, but the vibration in the Y direction is suppressed by the support by the Y direction datum unit 76 and the coil spring 86. Therefore, the Y direction datum unit 76 and the coil spring 86 are suppressed. Thus, even after the image forming apparatus 10 is operated, the natural frequency in the Y direction can be finely adjusted. Therefore, in the configuration of the present embodiment, it is easy to finely adjust the natural frequency in the Y direction, and the effect of suppressing the vibration in the Y direction with high sensitivity to banding is high.

  On the other hand, since the lens array 66 is above the print head 60, it is difficult to install the Z-direction datum portion 72 and the coil spring 82 in the arrangement region R of the print head 60, and vibration in the Z direction is more likely in the Y direction. In view of the fact that the sensitivity to the occurrence of banding is lower than the vibration of, vibration in the Z direction is suppressed by the rigidity of the print head 60 itself.

  In the present exemplary embodiment, a configuration in which adjustment is easily performed even after the image forming apparatus 10 is operated is adopted in a vibration direction (Y direction) that is highly sensitive to banding, and aims to suppress vibration. It is.

  Furthermore, when the coil spring 86 supports the print head 60 in the arrangement region R in which the LED array 62 in the X direction is arranged as in the present embodiment, there is a possibility that the print head 60 is bent in the Y direction. In this embodiment, since one point is supported by one coil spring 86, it is difficult to bend, and the accumulated tolerance is also reduced.

(Modification)
In the present embodiment, the Z-direction datum unit 72, the X-direction datum unit 74, and the Y-direction datum unit 76 are attached to and detached from the image forming apparatus main body 11 along the X direction integrally with the photoconductor module 21. However, the present invention is not limited to this. For example, the Z-direction datum unit 72, the X-direction datum unit 74, and the Y-direction datum unit 76 may be fixed to the image forming apparatus main body 11. In this configuration, for example, the photosensitive member 32 is not attached to or detached from the image forming apparatus main body 11, and the housing 23 of the photosensitive member 32 is fixed to the image forming apparatus main body 11. A configuration in which the X-direction datum unit 74 and the Y-direction datum unit 76 are fixed is conceivable.

  In this embodiment, the support frame 90 is provided. However, the present invention is not limited to this, and the print head 60 may be directly supported by the image forming apparatus main body 11.

  In the present embodiment, three coil springs 82, 84, 86 are provided in the Z direction, two in the X direction, and one in the Y direction. However, the present invention is not limited to this. Further, the number of the coil springs 82 and 86 is larger in the Z direction where the rigidity of the print head 60 itself is higher than in the Y direction where the rigidity is low, but the number is not limited to this, and the number may be small.

  Further, in the present embodiment, the coil spring 86 is configured by one, but may be configured by two (see FIG. 7) or three (see FIG. 8), or by four or more. May be.

  For example, when the coil spring 86 is composed of two as shown in FIG. 7, the distance between the coil spring 86A and the support position A1 and the distance between the coil spring 86B and the support position A2 are the same as the support position A1 and the support position A1. It is desirable that the distance to the position A2 is equal to a distance that is ¼. As a result, the natural frequency of the vibration system constituted by the print head 60 and the support structure 70 (coil springs 82, 84, 86) can be set high (high frequency).

  Further, when the coil spring 86 is composed of three as shown in FIG. 8, the distance between the coil spring 86A and the support position A1 and the distance between the coil spring 86C and the support position A2 are the same as the support position A1 and the support position A1. It is desirable that the distance to the position A2 is equal to 1/6. In addition, the coil spring 86 </ b> B is desirably disposed at the center in the longitudinal direction of the print head 60. As a result, the natural frequency of the vibration system constituted by the print head 60 and the support structure 70 (coil springs 82, 84, 86) can be set high (high frequency). In addition, the coil springs 86A and 86B86C are arranged in the Z direction so that the coil springs 86A and 86C are arranged on the upper side of the print head 60 and the coil spring 86B is arranged on the lower side of the print head 60. desirable.

  As described above, when there are a plurality of coil springs 86, the natural frequency can be easily adjusted by adjusting the interval, and the degree of freedom in design is improved. If there are a plurality of coil springs 86, there is a concern that the print head 60 may be bent in the Y direction. However, in a system that can correct the influence of the print head 60 on the image by image processing, the influence on the image may be reduced. Can be suppressed.

  The present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements can be made. For example, the modification examples described above may be appropriately combined.

10 Image Forming Device 32 Photoconductor (Example of Image Holding Body)
59 Exposure device (an example of a light irradiation device)
60 Print head (an example of an irradiation unit)
62A LED element (an example of an element)
82 Coil spring (an example of a first support)
86 Coil spring (an example of the second support part)

Claims (3)

Irradiating the irradiated surface with light and main-scanning the light in the main scanning direction, and an irradiating part having higher rigidity in the light irradiation direction than in the sub-scanning direction;
A first support portion that supports one end and the other end of the irradiation unit in the main scanning direction in the irradiation direction;
A second support part that supports the irradiation part in the sub-scanning direction between the first support part of the one end part and the first support part of the other end part;
A light irradiation apparatus comprising: The irradiation unit includes a plurality of elements that irradiate light to the irradiated surface along the main scanning direction.
The light irradiation apparatus according to claim 1, wherein the second support unit supports the irradiation unit in a region where the element is arranged in the main scanning direction. An image carrier,
The light irradiation device according to claim 1 or 2, wherein a light is applied to the surface of the image carrier as the irradiated surface to form a latent image.
An image forming apparatus comprising:

Images