Image forming apparatus and exposure apparatus

Abstract

To provide an image forming apparatus having a smaller size in a direction perpendicular to a direction in which an image carrier extends, compared to a structure where a positioner and an adjuster are spaced apart when viewed in a direction in which the image carrier extends.SOLUTION: An image forming apparatus includes: an image carrier that extends in a first direction; a light emitter that includes a substrate that extends in the first direction, and multiple light-emitting devices that are disposed on the substrate and emit light to the image carrier; a positioner that is disposed between the substrate and the image carrier and determines a position of the light emitter with respect to the image carrier in a direction perpendicular to the light emission direction; and an adjuster that is located to overlap the positioner when viewed in the first direction and adjusts a position of the light emitter in the light emission direction.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus and an exposure apparatus. [Background technology]

[0002] Patent Document 1 listed below discloses a focus adjustment device for an optical writing device that aligns the focal position of light irradiated from a plurality of light-emitting elements arranged in a row corresponding to each pixel in the main scanning direction in an image formation area with the surface of an image carrier, the focus adjustment device comprising: a storage means for storing a pattern image; an image forming means for forming an electrostatic latent image pattern on the surface of the image carrier corresponding to the pattern image stored in the storage means; a surface potential measuring means for measuring the surface potential of the electrostatic latent image pattern area on the surface of the image carrier formed by the image forming means; and a displacement mechanism for displacing the position of the optical writing device relative to the surface of the image carrier based on the surface potential measured by the surface potential measuring means so that the focal point of the light from the light-emitting elements aligns with the surface of the image carrier. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-22259 Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the present invention is to obtain an image forming apparatus and an exposure apparatus that can reduce the size in a direction perpendicular to the extension direction of the image carrier, compared to a configuration in which the positioning section and the adjustment section are separated when viewed from the extension direction of the image carrier. [Means for solving the problem]

[0005] The image forming apparatus of the first embodiment includes an image carrier extending in one direction, a base extending in the one direction, a light-emitting unit having a plurality of light-emitting elements disposed on the base and irradiating light onto the image carrier, a positioning unit disposed between the base and the image carrier and determining the position of the light-emitting unit in a direction perpendicular to the light irradiation direction of the image carrier, and an adjustment unit disposed at a position overlapping with the positioning unit when viewed from the one direction and adjusting the position of the light-emitting unit in the light irradiation direction.

[0006] The image forming apparatus of the second embodiment is the image forming apparatus of the first embodiment, and has a support member attached to the apparatus main body and rotatably supporting the image carrier, and the positioning portion is positioned in the direction perpendicular to the image carrier by contacting the support member, and the adjustment portion is positioned in a position overlapping with the positioning portion when viewed from the axial direction of the image carrier parallel to the one direction by contacting the support member.

[0007] An image forming apparatus of a third aspect is the image forming apparatus of the first or second aspect, wherein the adjustment unit is positioned further outward in the axial direction of the image carrier than the positioning unit.

[0008] In a fourth aspect of the image forming apparatus, in the third aspect of the image forming apparatus, the adjustment unit has a drive source that moves the light-emitting unit, and the drive source is arranged on the opposite side of the adjustment unit from the positioning unit in the axial direction of the image carrier.

[0009] An image forming apparatus of a fifth aspect is an image forming apparatus of any one of the second aspect, the third aspect which cites the second aspect, or the fourth aspect which cites the second aspect, wherein the positioning portion is a protrusion which protrudes from the base toward the support member and fits into a recess provided in the support member, the adjustment portion has a contact member which contacts the base and moves the base in the light irradiation direction, and the length of the contact surface of the contact member in the perpendicular direction is shorter than the length of the protrusion in the perpendicular direction.

[0010] The image forming apparatus of the sixth aspect is the image forming apparatus of the fifth aspect, and has a pressing member that is arranged on the opposite side of the base from the adjustment unit and presses the base toward the contact member, and the pressing member, the contact member, and the protrusion are each arranged on the same straight line extending in the light irradiation direction when viewed from the one direction.

[0011] An image forming apparatus of a seventh aspect is the image forming apparatus of the first aspect, wherein the positioning portion has a first positioning portion provided at one end side in the extension direction of the base and a second positioning portion provided at the other end side in the extension direction of the base, and the first positioning portion is constrained by a first restraining portion possessed by the image carrier to determine the position of the base in the width direction in the orthogonal direction, and the second positioning portion is constrained by a second restraining portion possessed by the image carrier to determine the position of the base in the extension direction and the width direction of the base in the orthogonal direction.

[0012] An eighth aspect of the image forming apparatus is the seventh aspect of the image forming apparatus, wherein the second positioning portion is a protrusion provided on the base, the second restraint portion is a recess into which the protrusion fits, and the portion of the recess that comes into contact with the protrusion in the extension direction of the image carrier is arc-shaped.

[0013] An image forming apparatus of a ninth aspect is an image forming apparatus of any one of the first to eighth aspects, further comprising a measuring device that is arranged adjacent to the light emitting element in the width direction of the base and measures the distance from the light emitting element to the outer peripheral surface of the image carrier, the measuring device being rectangular when viewed from the light irradiation direction, with its long side aligned with the extension direction of the base.

[0014] An image forming apparatus of a tenth aspect is the image forming apparatus of the ninth aspect, wherein the measuring device is disposed in the vicinity of a portion of the base with which the adjustment section comes into contact.

[0015] The exposure device of the eleventh embodiment includes a base extending in the same direction as an image carrier extending in one direction, a light-emitting unit having a plurality of light-emitting elements arranged on the base and irradiating light onto the image carrier, a positioning unit arranged between the base and the image carrier and determining the position of the light-emitting unit in a direction perpendicular to the light irradiation direction of the image carrier, and an adjustment unit arranged at a position overlapping with the positioning unit when viewed from the one direction and adjusting the position of the light-emitting unit in the light irradiation direction. [Effects of the Invention]

[0016] According to the image forming apparatus of the first aspect, the size in the direction perpendicular to the extension direction of the image carrier can be reduced compared to a configuration in which the positioning unit and the adjustment unit are separated when viewed in the extension direction of the image carrier.

[0017] According to the image forming apparatus of the second aspect, the positioning accuracy of the light emitting unit relative to the image carrier is improved compared to a configuration in which the positioning unit and the adjustment unit have different positioning standards.

[0018] According to the third embodiment of the image forming apparatus, it is easier to fine-tune the distance between the light-emitting unit and the image carrier, compared to a configuration in which the adjustment unit is located axially inward of the positioning unit (toward the center of the image carrier in the axial direction) in the image carrier.

[0019] According to the image forming apparatus of the fourth aspect, the drive source is easier to access than in a configuration in which the drive source is disposed on the positioning unit side of the adjustment unit in the axial direction of the image carrier.

[0020] According to the fifth embodiment of the image forming apparatus, the shift in the focal position of the light-emitting unit due to the tilt of the adjustment unit can be suppressed compared to a configuration in which the length of the contact surface of the contact member in a direction perpendicular to the light irradiation direction is longer than the length of the protrusion in a direction perpendicular to the light irradiation direction.

[0021] According to the sixth embodiment of the image forming apparatus, the size of the image forming unit in the direction perpendicular to the extension direction of the image carrier can be reduced compared to a configuration in which the pressing member, contact member, and protrusion are each arranged on different straight lines when viewed from one direction of the image carrier.

[0022] According to the seventh aspect of the image forming apparatus, distortion of the base due to the constraint can be suppressed compared to a configuration in which the first positioning section and the second positioning section restrict movement of the base in the extension direction and width direction of the base.

[0023] According to the image forming apparatus of the eighth aspect, the shape of the recessed portion that contacts the protrusion in the extension direction of the image carrier is angular, so that it is possible to suppress scuffing when the protrusion is tilted.

[0024] According to the image forming apparatus of the ninth aspect, the measuring device can be arranged at the center of the width of the base, compared to a configuration in which the long side of the measuring device is aligned along the width direction of the base.

[0025] According to the image forming apparatus of the tenth aspect, it is easier to fine-tune the distance between the light-emitting element and the outer peripheral surface of the image carrier, compared to a configuration in which the measuring device is positioned away from the part of the base where the adjustment unit contacts.

[0026] According to the exposure device of the eleventh aspect, the size in the direction perpendicular to the extension direction of the image carrier can be reduced compared to a configuration in which the positioning unit and the adjustment unit are separated when viewed in the extension direction of the image carrier. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a schematic view showing an image forming apparatus equipped with an exposure device according to a first embodiment. [Figure 2] FIG. 2 is a perspective view showing an exposure device used in the image forming apparatus. [Figure 3] FIG. 2 is a configuration diagram showing the exposure device as viewed from above and below. [Figure 4] FIG. 2 is a perspective view showing a plurality of light irradiation units of the exposure device. [Figure 5] FIG. 2 is an enlarged perspective view of a part of the exposure apparatus. [Figure 6] 2 is a cross-sectional view showing a state in which a plurality of light irradiation units of the exposure device are cut in the short side direction. FIG. [Figure 7]FIG. 2 is a cross-sectional view showing the exposure device cut in the short direction. [Figure 8] FIG. 2 is a perspective view showing a light irradiation unit of the exposure device. [Figure 9] FIG. 2 is a perspective view showing a state in which a part of the light irradiation unit is cut in the short side direction. [Figure 10] FIG. 2 is a side view showing a positioning unit and an adjustment unit on one side in the depth direction of the exposure apparatus. [Figure 11] FIG. 2 is a side view, with a portion of the adjustment unit of the exposure device in cross section. [Figure 12] FIG. 2 is a front view, with a portion of the adjustment unit of the exposure device in cross section. [Figure 13] FIG. 10 is a side view showing the positioning unit and the adjustment unit on the other side in the depth direction of the exposure apparatus. [Figure 14] 14X-14X cross-sectional view of FIG. 10. [Figure 15] 11 is a view showing the relationship between the positioning unit, the adjustment unit, and the pressing unit shown in FIG. 10, as viewed in the depth direction of the device. [Figure 16] 16 is an enlarged cross-sectional view of a portion indicated by an arrow 16X in FIG. 10. [Figure 17] FIG. 14 is an enlarged cross-sectional view of a portion indicated by an arrow 17X in FIG. [Figure 18] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, an embodiment of the present invention (hereinafter referred to as the present embodiment) will be described.

[0029] [First embodiment] <Image forming apparatus 10> 1 is a schematic diagram showing the configuration of an image forming apparatus 10 equipped with an exposure device 40 according to a first embodiment. First, the configuration of the image forming apparatus 10 will be described. Next, the exposure device 40 used in the image forming apparatus 10 will be described. The image forming apparatus 10 is, as an example, an image forming apparatus that forms images in multiple colors, such as a full-color printer for commercial printing that requires particularly high image quality.

[0030] Furthermore, the image forming apparatus 10 is a wide-width image forming apparatus that supports widths exceeding the width of the recording medium P when B3 is fed vertically (i.e., widths exceeding 364 mm). As an example, it supports recording media P with sizes of 420 mm or more for A2 vertical feeding and 1456 mm or less for B0 horizontal feeding. For example, the image forming apparatus 10 supports 728 mm for B2 horizontal feeding.

[0031] The image forming apparatus 10 shown in FIG. 1 is an example of an image forming apparatus that forms an image on a recording medium. Specifically, the image forming apparatus 10 is an electrophotographic image forming apparatus that forms a toner image (an example of an image) on a recording medium P. Toner is an example of powder. More specifically, the image forming apparatus 10 includes an image forming unit 14 and a fixing device 16. Each unit of the image forming apparatus 10 (the image forming unit 14 and the fixing device 16) will be described below.

[0032] (Image forming unit 14) The image forming unit 14 has a function of forming a toner image on the recording medium P. Specifically, the image forming unit 14 has a toner image forming unit 22 and a transfer device 17.

[0033] <Toner image forming unit 22> 1 is provided so as to form a toner image for each color. In this embodiment, toner image forming units 22 for a total of four colors, yellow (Y), magenta (M), cyan (C), and black (K), are provided. (Y), (M), (C), and (K) shown in FIG. 1 indicate components corresponding to the above colors.

[0034] Since the toner image forming units 22 for each color are configured in the same manner except for the toner used, the respective parts of the toner image forming unit 22(K) are denoted by reference numerals in FIG. 1 as a representative of the toner image forming units 22 for each color.

[0035] Specifically, each toner image forming unit 22 for each color has a photosensitive drum 32 that rotates in one direction (for example, counterclockwise in FIG. 1). Here, the photosensitive drum 32 is an example of an image carrier. Furthermore, each toner image forming unit 22 for each color has a charger 23, an exposure device 40, and a developing device 38.

[0036] In the toner image forming unit 22 for each color, the charger 23 charges the photosensitive drum 32. Furthermore, the exposure device 40 exposes the photosensitive drum 32 charged by the charger 23 to light, thereby forming an electrostatic latent image on the photosensitive drum 32. Furthermore, the developing device 38 develops the electrostatic latent image formed on the photosensitive drum 32 by the exposure device 40, thereby forming a toner image.

[0037] The photosensitive drum 32 rotates while holding the electrostatic latent image formed as described above on its outer periphery, and the electrostatic latent image is transported to the developing device 38. The specific configuration of the exposure device 40 will be described later.

[0038] -Transfer device 17- 1 is a device that transfers the toner image formed in the toner image forming unit 22 onto a recording medium P. Specifically, the transfer device 17 performs primary transfer of the toner image of each color on the photosensitive drum 32 onto a transfer belt 24 serving as an intermediate transfer body, superimposing the toner image, and then performs secondary transfer of the superimposed toner image onto the recording medium P. Specifically, as shown in FIG. 1, the transfer device 17 includes the transfer belt 24, a primary transfer roll 26, and a secondary transfer roll 28.

[0039] The primary transfer roll 26 is a roll that transfers the toner image of each color on the photosensitive drum 32 to the transfer belt 24 at a primary transfer position T1 between the photosensitive drum 32 and the primary transfer roll 26. In this embodiment, a primary transfer electric field is applied between the primary transfer roll 26 and the photosensitive drum 32, so that the toner image formed on the photosensitive drum 32 is transferred to the transfer belt 24 at the primary transfer position T1.

[0040] The toner image is transferred from the photosensitive drum 32 of each color onto the outer peripheral surface of the transfer belt 24. Specifically, the transfer belt 24 is configured as follows: As shown in Fig. 1, the transfer belt 24 is annular and is wound around multiple rolls 39 to determine its position.

[0041] The transfer belt 24 rotates in the direction of arrow A, for example, when a drive roll 39D among the plurality of rolls 39 is rotationally driven by a drive unit (not shown). Of the plurality of rolls 39, a roll 39B shown in FIG. 1 is an opposing roll 39B that faces the secondary transfer roll 28.

[0042] The secondary transfer roll 28 is a roll that transfers the toner image transferred to the transfer belt 24 to the recording medium P at a secondary transfer position T2 between the opposing roll 39B and the secondary transfer roll 28. In this embodiment, a secondary transfer electric field is applied between the opposing roll 39B and the secondary transfer roll 28, so that the toner image transferred to the transfer belt 24 is transferred to the recording medium P at the secondary transfer position T2.

[0043] -Fuser 16- The fixing device 16 shown in Fig. 1 is a device that fixes a toner image transferred to a recording medium P by a secondary transfer roll 28 to the recording medium P. Specifically, as shown in Fig. 1, the fixing device 16 has a heating roll 16A as a heating member and a pressure roll 16B as a pressure member. In the fixing device 16, the toner image formed on the recording medium P is fixed to the recording medium P by heating and pressurizing the recording medium P with the heating roll 16A and the pressure roll 16B.

[0044] <Exposure device 40> Next, the configuration of the exposure apparatus 40, which is a main part of this embodiment, will be described. FIG. 2 is a perspective view showing the configuration of the exposure apparatus 40. FIG. 3 is a plan view showing the exposure apparatus 40 as viewed from above and below. In the following description, the arrow Y direction shown in the figure will be described as the width direction of the exposure apparatus 40, and the arrow Z direction will be described as the height direction of the exposure apparatus 40. Furthermore, the arrow X direction, which is perpendicular to both the apparatus width direction and the apparatus height direction, will be described as the depth direction of the exposure apparatus 40. Note that the width direction and height direction described above are directions defined for the convenience of explanation, and the configuration of the exposure apparatus 40 is not limited to these directions.

[0045] First, the overall configuration of the exposure apparatus 40 will be described, and then each component of the exposure apparatus 40 will be described.

[0046] As shown in FIG. 10, the exposure device 40 includes a light emitting unit 41, a positioning unit 160, and a position adjusting unit .

[0047] (Light emitting part 41) As shown in Figures 2 and 3, the light-emitting unit 41 includes a base 42 extending in one direction (the direction of arrow X in this embodiment) and a plurality of light irradiation units 44 provided on one side of the base 42 in the direction of arrow Z (the upper side in the up-down direction in Figures 2 and 3). In this embodiment, three light irradiation units 44 extending in one direction of the base 42 are provided. The base 42 is an elongated member that is rectangular in plan view as shown in Figure 3. The light irradiation units 44 each have the same configuration and are elongated members that are rectangular in plan view as shown in Figure 3.

[0048] As an example, the three light irradiation units 44 are arranged offset in one direction of the base 42, i.e., in the extension direction of the base 42 (arrow X direction), and are also arranged offset in a width direction perpendicular to the one direction of the base 42, i.e., in the short side direction of the base 42 (arrow Y direction). The light emitting unit 41 is arranged along the axial direction of the photosensitive drum 32 (see FIG. 1). The length of the light emitting unit 41 in one direction is equal to or greater than the length of the photosensitive drum 32 in the axial direction. One or more of the three light irradiation units 44 faces the surface (outer peripheral surface) of the photosensitive drum 32. This allows the light emitted from the light emitting unit 41 to be irradiated onto the surface of the photosensitive drum 32.

[0049] 2 and 3, the side of the base 42 on which the light irradiation unit 44 is provided is illustrated as being the upper side in the vertical direction, and light is irradiated from the light irradiation unit 44 toward the upper side, but in the image forming apparatus 10 shown in Fig. 1, the up-down direction of the exposure device 40 is reversed. That is, in Fig. 1, the exposure device 40 is disposed so that the side of the base 42 on which the light irradiation unit 44 is provided is the lower side in the vertical direction, and light is irradiated from the light irradiation unit 44 toward the photosensitive drum 32 below.

[0050] In this embodiment, the three light irradiation units 44 are arranged in a staggered pattern when viewed from the top, bottom, and upper sides of the exposure device 40 (see FIG. 3). More specifically, two light irradiation units 44 are arranged on one side of the short side of the base 42 at both end sides in one direction of the base 42. One light irradiation unit 44 is arranged on the other side of the short side of the base 42 at the center in one direction of the base 42. The ends of the two light irradiation units 44 arranged on one side of the short side of the base 42 and the end of the one light irradiation unit 44 arranged on the other side of the short side of the base 42 overlap with each other when viewed in the short side of the base 42. In other words, in one direction of the base 42, part of the irradiation ranges of light from the three light irradiation units 44 overlap.

[0051] 4 and 5, the exposure device 40 includes a harness 46 electrically connected to each of the three light irradiation units 44, a plurality of brackets 48 for holding the harness 46, and a lower cover 50 for externally covering the harness 46 and the brackets 48. The harness 46 is an assembly of a plurality of wires used for power supply. The brackets 48 are attached to the base 42 and extend from the base 42 to the other side in the direction of arrow Z (the lower side in the vertical direction in FIG. 2). The lower cover 50 is attached to the other side of the base 42 in the direction of arrow Z (the lower side in the vertical direction in FIG. 2).

[0052] 2 and 3, the exposure device 40 is provided with side covers 52 that cover the sides of the three light irradiation units 44. The side covers 52 are plate-shaped, and their lower end sides are attached to both sides in the short direction of the base 42. The exposure device 40 is also provided with a cleaning device 54 that cleans the lens units 68 of the light irradiation units 44, which will be described later.

[0053] 5 and 6, the exposure device 40 also includes a plurality of spacers 56 sandwiched between the base 42 and the light irradiation unit 44, and a fastening member 58 that fixes the light irradiation unit 44 to the base 42 with the plurality of spacers 56 interposed therebetween. The fastening member 58 is, for example, a member that has a spiral groove and fastens using this groove. In other words, it is a member that has a screw mechanism, such as a screw, bolt, or screw.

[0054] Although not shown, positioning portions 160 that protrude upward in the vertical direction are provided on both ends of the base 42 in one direction. The positioning portions 160 are constrained by constraining portions 34 that are provided on drum flanges 33, which are an example of support members that rotatably support both ends of the photosensitive drum 32, and determine the position of the light emitting portion 41 in a direction perpendicular to the light irradiation direction with respect to the photosensitive drum 32. Specifically, the position of the light emitting portion 41 in the short side direction (Y direction) with respect to the photosensitive drum 32 is determined.

[0055] 5 to 8, the base 42 is made up of a rectangular parallelepiped elongated member. The base 42 is disposed in a position facing the entire axial length of the photosensitive drum 32 (FIG. 1).

[0056] A recess 80 into which the spacers 56 are inserted is provided on the surface 42A on the upper side in the vertical direction (arrow Z direction) of the base 42 (see FIG. 6). As an example, three spacers 56 are arranged at intervals in one direction for one light irradiation unit 44. In this embodiment, three spacers 56 are arranged for each of the three light irradiation units 44.

[0057] The recess 80 includes an inclined surface 80A that forms the bottom surface and is inclined relative to the surface 42A of the base 42, a vertical wall 80B disposed at the downward end of the inclined surface 80A, and two vertical walls (not shown) disposed opposite each other on both sides of the inclined surface 80A (see FIG. 5). As an example, the inclined surface 80A facing the two light irradiators 44 disposed on one side of the base 42 in the short direction and the inclined surface 80A facing the one light irradiator 44 disposed on the other side of the base 42 in the short direction are inversely inclined. In the light-emitting unit 41, the inclined surface 80A with an inverse inclination is adjusted so that light is irradiated toward the center of the photosensitive drum 32 (see FIG. 1) from the two light irradiators 44 disposed on one side of the base 42 in the short direction and the one light irradiator 44 disposed on the other side of the base 42 in the short direction. When there is one light irradiator 44, the light irradiating direction of the light emitting unit 41 onto the photosensitive drum 32 is the optical axis direction of the light irradiator 44. On the other hand, when there are multiple light irradiators 44 as in this embodiment, the light irradiating direction is the direction from the midpoint in the lateral direction (Y direction) of the base 42 between the principal points of each light irradiator 44 toward the focal point when viewed from one direction (X direction) of the base 42. In this embodiment, the position and angle of each light emitting unit 41 are adjusted so that the light irradiating direction is the direction toward the center of the photosensitive drum 32.

[0058] In this embodiment, the base 42 is made of a metal block. The metal block in this embodiment does not include general sheet metal that is formed into a shape by bending, but refers to a metal block that is thick enough that it cannot be bent into a shape used as the base of the exposure device 40. As an example, the base 42 is a metal block whose thickness is 10% or more of the width of the base 42. Furthermore, the base 42 may be made of a metal block whose thickness is 20% or more and 100% or less of the width of the base 42.

[0059] Conventional wide-format image forming devices are used for outputting black-and-white drawings, which do not require high image quality compared to full-color printers for commercial printing, and use sheet metal as the base. On the other hand, the image forming device 10 of this embodiment is a full-color printer for commercial printing, which requires high image quality. Therefore, to prevent the bending of the base 42 from affecting image quality, a metal block with higher rigidity than sheet metal is used.

[0060] The base 42 is made of, for example, steel or stainless steel. However, the base 42 may be made of a metal block other than steel or stainless steel. For example, aluminum, which has higher thermal conductivity and is lighter than steel or stainless steel, may be used. However, in this embodiment, heat generated by the light source 64 is mainly dissipated by the support 60. Therefore, steel or stainless steel is used for the base 42, as rigidity takes priority over thermal conductivity and weight.

[0061] Furthermore, the thickness of the base 42 in the vertical direction (arrow Z direction) is preferably greater than the thickness of the support 60 that constitutes the light irradiation unit 44. This makes the rigidity (bending rigidity in the arrow Z direction) of the base 42 greater than the rigidity of the light irradiation unit 44. The thickness of the base 42 in the vertical direction is preferably 5 mm or more, more preferably 10 mm or more, and even more preferably 20 mm or more.

[0062] As shown in FIG. 6 , a recessed portion 82 is formed on the back surface 42B of the base 42 opposite the front surface 42A, the recessed portion 82 being cut out toward the spacer 56, i.e., toward the recessed portion 80. The recessed portions 82 are provided at positions corresponding to the recessed portions 80 of the base 42. The recessed portions 82 are formed obliquely from the back surface 42B of the base 42 toward the center of the base 42 in the short direction (Y direction). For example, the recessed portion 82 has a circular shape when viewed from the back surface 42B of the base 42. The inner diameter of the recessed portion 82 is larger than the outer shape of the head 58A of the fastening member 58. A through-hole 84 is provided in the bottom surface 82A of the recessed portion 82, through which the shank 58B of the fastening member 58 penetrates the base 42. The through-hole 84 opens into the inclined surface 80A of the recessed portion 80.

[0063] 2 to 7, the three light irradiation units 44 have the same configuration as described above. As an example, the two light irradiation units 44 on one side in the short side direction of the base 42 and the one light irradiation unit 44 on the other side in the short side direction of the base 42 are arranged symmetrically in the short side direction of the base 42.

[0064] As shown in FIG. 6 , the light irradiation unit 44 includes a support 60 extending in one direction (the direction of the arrow X) and a light-emitting element substrate 62 supported on the surface of the support 60 opposite the base 42 in the vertical direction (the direction of the arrow Z) (in this embodiment, the upper surface in the vertical direction). The light-emitting element substrate 62 is provided with a plurality of light sources 64 arranged along one direction. In this embodiment, the light source 64 includes, for example, a plurality of light-emitting elements. As an example, the light source 64 is a light-emitting element array having a semiconductor substrate and a plurality of light-emitting elements formed on the semiconductor substrate along one direction. In this embodiment, the light source 64, i.e., the light-emitting element array, is arranged in a staggered pattern along one direction on the light-emitting element substrate 62. Note that the light source 64 may not be a light-emitting element array, but may be a single light-emitting element. Furthermore, each light-emitting element is composed of a light-emitting diode, a light-emitting thyristor, a laser element, or the like, and has, for example, a resolution of 2400 dpi when arranged along one direction. The light-emitting element substrate 62 is a substrate for causing one or more of the plurality of light sources 64 to emit light. In FIG. 6, only one light source 64 provided in the light irradiation unit 44 is shown, and the other light sources are not shown.

[0065] The light irradiation section 44 also includes a pair of mounting sections 66 provided on the surface of the light-emitting element substrate 62 opposite the support body 60, and a lens section 68 held in a sandwiched state between the upper ends of the pair of mounting sections 66.

[0066] The pair of mounting portions 66 and the lens portion 68 extend in one direction of the support body 60 (see FIG. 4, etc.). The lens portion 68 is disposed in a position facing the plurality of light sources 64, and a space is provided between the lens portion 68 and the plurality of light sources 64. In the exposure device 40, light emitted from the plurality of light sources 64 passes through the lens portion 68 and is irradiated onto the surface of the photosensitive drum 32 (see FIG. 1), which is an object to be irradiated.

[0067] The support 60 is made of a rectangular parallelepiped member. In this embodiment, the support 60 is made of a metal block, similar to the base 42. For example, the support 60 is made of steel or stainless steel. Here, the base 42 may be made of a metal block other than steel or stainless steel. For example, it may be made of aluminum, which has a higher thermal conductivity than steel or stainless steel and is lighter. However, if the thermal expansion coefficients of the base 42 and the support 60 differ, distortion or bending may occur. Therefore, from the viewpoint of suppressing distortion or bending, it is preferable that the base 42 and the support 60 are made of the same material.

[0068] A screw hole 74 into which the shaft portion 58B of the fastening member 58 is fastened is formed in the surface of the support body 60 facing the base body 42 (see FIG. 6). The screw hole 74 is provided in a position facing the through hole 84 of the base body 42.

[0069] The fastening member 58 is inserted into the recessed portion 82 of the base 42, and the shaft portion 58B of the fastening member 58 is fastened to the screw hole 74 of the support body 60 via the spacer 56, with the shaft portion 58B of the fastening member 58 passing through the through-hole 84 of the base 42. In this way, the light irradiation unit 44 is fixed to the base 42 from inside the recessed portion 82 of the base 42 by the fastening member 58. With the light irradiation unit 44 fixed to the base 42 by the fastening member 58, the spacer 56 is interposed between the base 42 and the support body 60.

[0070] Here, a method can be considered in which the fastening member 58 is used to fasten the support 60 from the front side (the light output surface side) to the front side of the base 42. However, unlike supports made of resin material or supports made of sheet metal, the support 60 of this embodiment is made of a heavy metal block. Therefore, the fastening member 58 must be sized to match the mass. In this case, space for the large fastening member 58 is required on the front side of the support 60, which increases the size of the support 60. Therefore, in this embodiment, the support 60 is fastened from the back side.

[0071] Furthermore, in a configuration in which fastening members 58 are provided not only on both end sides of support body 60 but also on the central side, the presence of light source 64 on the central side makes it difficult to configure the fastening from the front side of support body 60. Therefore, by configuring the fastening from the back side of base 42, it becomes possible to fasten both end sides and the central side of support body 60 only from the back side of base 42.

[0072] The screw hole 74 and the recessed portion 82 of the base 42 are provided at a position that overlaps with the light source 64 when viewed from the optical axis direction of the light source 64. With this configuration, heat generated by the light source 64 is more easily dissipated toward the base 42 via the fastening member 58 compared to when the screw hole 74 and the recessed portion 82 are provided at a position that does not overlap with the light source 64.

[0073] As shown in Figures 6, 7, 8, and 9, the light irradiation unit 44 has a drive substrate 72 attached to the support body 60 via a fixture 70. Here, the drive substrate 72 is an example of a substrate. The drive substrate 72 extends in one direction (the direction of arrow X). The length of the drive substrate 72 in one direction is shorter than the length of the support body 60 in one direction (see Figure 8). The drive substrate 72 is a substrate for driving the light irradiation unit 44, and for example, an ASIC substrate (application specific integrated circuit) or the like is used.

[0074] The mounting fixture 70 includes a fastening bolt 70A and a tube 70B disposed between the support body 60 and the drive substrate 72 (see FIG. 9). As an example, the tube 70B is made of metal and is joined to the drive substrate 72 by soldering or the like. Although not shown, the drive substrate 72 has an opening formed therein that communicates with the through-hole of the tube 70B. The shaft of the fastening bolt 70A is configured to pass through the tube 70B. The shaft of the fastening bolt 70A passes through the tube 70B from the drive substrate 72 side and is fastened to the support body 60, thereby mounting the drive substrate 72 to the support body 60. The drive substrate 72 is mounted to the support body 60 by two mounting fixtures 70 disposed at both ends of the drive substrate 72 in one direction.

[0075] The surface of the drive substrate 72 (i.e., the plate surface) is arranged along the inner side portion 60A of the support 60 in the short-side direction of the base 42 (see FIG. 7). Here, the inner side portion 60A of the support 60 refers to the side closer to the center of the base 42 in the short-side direction.

[0076] A gap is formed between the inner side portion 60A of the support body 60 and the surface (plate surface) of the drive substrate 72 by the tubular body 70B of the mounting fixture 70. In other words, the drive substrate 72 is attached by the mounting fixture 70 without directly contacting the inner side portion 60A of the support body 60 in the light irradiation unit 44.

[0077] The inner side portion 60A of the support 60 is an inclined surface that is inclined inward with respect to the surface 42A of the base 42. Like the inner side portion 60A, the plate surface of the drive substrate 72 is also inclined inward with respect to the surface 42A of the base 42.

[0078] The three light emitting units 44 each have a drive substrate 72 provided on the inner side portion 60A of the support 60.

[0079] 3 and 4, the drive substrate 72 provided in one light irradiation unit 44 in a side view is provided at a position that does not overlap with another light irradiation unit 44 adjacent to the one light irradiation unit 44. The lengths in one direction (the direction of arrow X) of the drive substrates 72 arranged in each of the three light irradiation units 44 on the base 42 are the same, and are shorter than the length of the light irradiation unit 44 arranged in the center in one direction that does not overlap with the light irradiation units 44 on both sides in one direction.

[0080] 7, 8, and 9, three flexible cables 100 are connected to the light-emitting element substrate 62 on the upper side of the support 60, and the three flexible cables 100 extend from the upper part of the inner side portion 60A of the support 60 to the outside of the support 60. The three flexible cables 100 extending to the outside of the support 60 are electrically connected to three drive elements 73 provided on the drive substrate 72, respectively. The drive elements 73 may be, for example, integrated circuits.

[0081] Furthermore, a connector 104 is provided at the middle of one direction of the drive substrate 72 to which a flat cable 102 from outside the light irradiation unit 44 is electrically connected. The connection port of the connector 104 is arranged in a direction intersecting the surface (plate surface) of the drive substrate 72. The connection portion of the flat cable 102 can be inserted into and removed from the connector 104 in a direction intersecting the surface (plate surface) of the drive substrate 72. Here, the flat cable 102 is an example of wiring.

[0082] As shown in FIG. 7 , the flat cable 102 connected to the connector 104 extends from the drive substrate 72 to the opposite side from the support 60. A through-hole 106 that penetrates the base 42 in the up-down direction (the direction of the arrow Z) is formed in the base 42 at a position corresponding to the position where the flat cable 102 is connected to the drive substrate 72. The through-hole 106 is provided on the lateral side of the drive substrate 72 in the base 42, on the opposite side from the light irradiation unit 44 that includes the drive substrate 72 (i.e., a position where the light irradiation unit 44 is not disposed). The flat cable 102 is inserted through the through-hole 106 of the base 42, and is routed inside the lower cover 50 on the rear surface 42B side of the base 42. In other words, the flat cable 102 is disposed inside the lower cover 50.

[0083] 4 and 5, a flat cable 102 is connected to the drive substrate 72 provided in each of the three light irradiation units 44 via a connector 104. A through-hole 106 is provided in the base 42 on the lateral side of the drive substrate 72 of each of the three light irradiation units 44. The flat cable 102 of each of the three light irradiation units 44 is inserted into the through-hole 106 of the base 42, and extends inside the lower cover 50 on the rear surface 42B side of the base 42 (see FIG. 7).

[0084] As an example, the light irradiating unit 44 has a height longer than a width longer than a length perpendicular to one direction (arrow X direction). That is, the light irradiating unit 44 has a length longer in the up-down direction (arrow Z direction) than a length in the short side direction. Therefore, the center of gravity of the light irradiating unit 44 is higher than when the light emitting unit has a height shorter than a width longer than a length perpendicular to one direction.

[0085] 6, the spacer 56 is sandwiched between the base 42 and the light irradiation unit 44 in the optical axis direction of the light source 64. As an example, the spacer 56 is plate-shaped and made of one member (i.e., a single member). In this embodiment, the spacer 56 is U-shaped when viewed in the optical axis direction of the light source 64. The spacer 56 includes a main body 56A and a recessed portion 56B cut out from one side of the main body 56A.

[0086] The spacer 56 is disposed on the inclined surface 80A of the recess 80 of the base 42. At the position where the spacer 56 is disposed on the inclined surface 80A, the thickness of the spacer 56 is equal to or greater than the depth of the recess 80. The fastening member 58 fixes the light irradiation unit 44 to the base 42 in a manner that a compressive load is applied to the spacer 56.

[0087] As shown in FIG. 7 , the bracket 48 has a function of holding the flat cable 102. Here, the bracket 48 is an example of a holding member. More specifically, the bracket 48 includes a U-shaped support portion 48A that protrudes from the back surface 42B of the base 42 toward the opposite side from the light irradiation portion 44, and a pair of attachment portions 48B that are bent inward from the upper end of the support portion 48A (i.e., toward the inside in the short direction of the base 42). The support portion 48A includes a flat portion 49 that faces the back surface 42B of the base 42, at a middle portion on the lower side of the U-shape. The support portion 48A has a shape such that the side opposite the flat portion 49 opens toward the base 42. The pair of attachment portions 48B are attached to the base 42 by fastening members 110 while in surface contact with the back surface 42B of the base 42.

[0088] A plurality of brackets 48 are provided at intervals in one direction of the base body 42 (see FIG. 5). A flat cable 102 is held on a flat surface 49 of the support portion 48A. The flat cable 102 is supported by the plurality of brackets 48, and is arranged inside the lower cover 50 along one direction of the base body 42.

[0089] 4 and 7, the lower cover 50 covers the harnesses 46 and flat cables 102 electrically connected to the three light irradiators 44, respectively. The lower cover 50 is attached to the lower side of the base 42 in the vertical direction (i.e., the side of the back surface 42B of the base 42 shown in FIG. 5), protrudes from the base 42 on the side opposite the light irradiators 44, and covers part of the back surface 42B of the base 42. In this embodiment, the lower cover 50 has a U-shaped cross section, and the upper end of the lower cover 50 is attached to both sides of the base 42 in the short direction by a plurality of fastening members 86. The lower cover 50 can be attached to and detached from the base 42 by fastening and removing the plurality of fastening members 86.

[0090] The lower cover 50 is configured to raise the position of the base 42 when the lower surface is placed flat. Because the base 42 is made of a metal block, raising the position of the base 42 raises the center of gravity of the exposure device 40.

[0091] 2, 6, and 7, the side covers 52 are provided at both ends in the short direction of the base 42. The side covers 52 are arranged in one direction on the sides of the three light irradiating units 44. As a result, the side covers 52 have the function of protecting the three light irradiating units 44 from the outside.

[0092] The side cover 52 is provided at a position overlapping with the three light irradiation units 44 in a side view (viewed from the direction of arrow Y) of the exposure device 40. The length of the side cover 52 in one direction (the direction of arrow X) is longer than the length region of the base 42 in which the three light irradiation units 44 are arranged (see FIGS. 2 and 3).

[0093] As shown in Fig. 7, support portions 122 that support the side covers 52 are provided on the inside of the side covers 52. Mounting portions 120 are provided on the surface 42A of the base 42 at the ends in the shorter direction, and the support portions 122 are supported by the mounting portions 120. The support portions 122 come into contact with the side covers 52, thereby supporting the side covers 52 so that they do not fall toward the light irradiation unit 44. The support portions 122 are provided on the side covers 52 on both sides in the shorter direction of the base 42. Although not shown, a plurality of support portions 122 are provided at intervals in one direction of the side covers 52.

[0094] (positioning part 160) 10 and 13, the positioning portion 160 is disposed between the base 42 and the photosensitive drum 32 and determines the position of the light-emitting portion 41 relative to the photosensitive drum 32 in a direction perpendicular to the light emission direction of the light-emitting portion 41. Specifically, the positioning portion 160 determines the position of the light-emitting portion 41 in the Y direction, which is a direction perpendicular to the light emission direction of the light-emitting portion 41. In this embodiment, the positioning portion 160 includes a first positioning portion 160A provided at one end side (the left side in FIG. 10, i.e., the front side in the device depth direction) in the direction in which the base 42 extends (the X direction), and a second positioning portion 160B provided at the other end side (the right side in FIG. 13, i.e., the back side in the device depth direction) in the direction in which the base 42 extends (the X direction). Note that the first positioning portion 160A and the second positioning portion 160B are made of the same components, and therefore the same components will be described as the positioning portion 160.

[0095] The positioning portion 160 is positioned in the Y direction relative to the photosensitive drum 32 by contacting the drum flange 33. Specifically, the positioning portion 160 is a cylindrical protrusion that protrudes from the surface 42A of the base 42 toward the drum flange 33. The shape of the positioning portion 160 is not limited to this configuration. The shape of the positioning portion 160 may be a polygonal pillar, an elliptical pillar, or any other shape. The positioning portion 160, which is a cylindrical protrusion, is adapted to fit into the restraining portion 34 of the drum flange 33. Here, in this embodiment, as described above, both axial ends of the photosensitive drum 32 are rotatably supported by the pair of drum flanges 33. The pair of drum flanges 33 are attached to the device main body (not shown) (here, the frame of the image forming unit 12). Of the pair of drum flanges 33, the drum flange 33 on the front side in the device depth direction (left side in FIG. 10) is provided with a first restraining portion 34A, and the drum flange 33 on the rear side in the device depth direction (right side in FIG. 13) is provided with a second restraining portion 34B. A first positioning portion 160A fits into the first restraining portion 34A, and a second positioning portion 160B fits into the second restraining portion 34B.

[0096] As shown in FIG. 16 , the first restraining portion 34A is a recess extending in the X direction. In other words, the first restraining portion 34A is a groove extending in the X direction with both ends open. When the first positioning portion 160A fits into the first restraining portion 34A, movement of the first positioning portion 160A in the Y direction is restricted by a pair of wall surfaces 35A of the first restraining portion 34A that face each other in the Y direction. That is, the first positioning portion 160A determines the position of the light-emitting unit 41 in the Y direction by being restrained by the first restraining portion 34A. On the other hand, because the first restraining portion 34A is a groove extending in the X direction, movement of the first positioning portion 160A in the X direction is not restricted.

[0097] As shown in FIG. 17, the second restraint portion 34B is a recess extending in the X direction. In other words, the second restraint portion 34B is a groove extending in the X direction and having one end in the X direction (the right end in FIG. 17) closed by a wall surface 35A. The other end in the X direction of the second restraint portion 34B (the left end in FIG. 17) is closed by a cylindrical portion 35B. This cylindrical portion 35B is provided across a pair of wall surfaces 35C of the second restraint portion 34B that face each other in the Y direction. Here, when the second positioning portion 160B fits into the second restraint portion 34B, movement of the second positioning portion 160B in the Y direction is restricted by the pair of wall surfaces 35C of the second restraint portion 34B that face each other in the Y direction. On the other hand, because the wall surface 35A and the cylindrical portion 35B are provided with a gap in the X direction, the second restraint portion 34B also restricts movement of the second positioning portion 160B in the X direction. That is, the second positioning portion 160B determines the position of the light-emitting unit 41 in the X direction and the Y direction by being restrained by the second restraint portion 34B. Note that the portion of the second restraint portion 34B that comes into contact with the first positioning portion 160A in the X direction is the outer periphery of the cylindrical portion 53B. That is, the portion of the second restraint portion 34B that comes into contact with the first positioning portion 160A in the X direction is arc-shaped.

[0098] (Position adjustment section 130) 10 to 12, the position adjustment unit 130, which is an example of an adjustment unit, is a mechanism that adjusts the distance between the light emitting unit 41 and the photosensitive drum 32. Specifically, the position adjustment unit 130 adjusts the position of the light emitting unit 41 in the light irradiation direction relative to the photosensitive drum 32. More specifically, the position adjustment unit 130 moves the light emitting unit 41 in the light irradiation direction to adjust the position of the light emitting unit 41 in the light irradiation direction relative to the photosensitive drum 32. In this embodiment, the light irradiation direction of the light emitting unit 41 is substantially the same as the Z direction.

[0099] As shown in FIG. 10, the position adjustment unit 130 includes a contact member 132, a shaft member 134, and a moving member 136.

[0100] -Contact member 132- 10, the contact member 132 is a member whose outer circumferential surface 132A contacts the surface 42A of the base 42. The contact member 132 is disk-shaped and rotatably supported by a shaft member 134. Specifically, the contact member 132 is supported by the shaft member 134 so as to rotate relative to the shaft member 134. As an example, the contact member 132 of this embodiment is a ball bearing.

[0101] The shaft member 134 is a member that rotatably supports the contact member 132. The shaft member 134 supports the contact member 132 so that it can rotate relative to the shaft member 132. As shown in FIGS. 10 and 12 , the shaft member 134 is a substantially cylindrical member, and both axial ends thereof are received by a pair of receiving portions 138. Specifically, the pair of receiving portions 138 are arranged opposite each other in the X direction, which is the short-side direction of the base 42. The pair of receiving portions 138 are portions that receive the shaft member 134 so that it can rotate with the X direction as its axial direction and move in the light irradiation direction. In other words, the contact member 132 is disposed between the pair of receiving portions 138 of the shaft member 134.

[0102] 12, the pair of receiving portions 138 are hole walls of elongated holes formed in a pair of support plates 140 arranged opposite each other in the X direction with the contact member 132 sandwiched between them. The longitudinal direction of these elongated holes is in the Z direction. Therefore, both axial ends of the shaft member 134 can be supported rotatably and movably in the light irradiation direction. In addition, stoppers (not shown) are attached to both axial ends of the shaft member 134 to prevent it from coming off.

[0103] As shown in FIG. 11, the outer diameter D1 of the contact member 132 is larger than the outer diameter D2 of the shaft member 134.

[0104] As shown in FIG. 11, the moving member 136 is a member that comes into contact with the shaft member 134 and moves the shaft member 134 in the light emission direction of the light emitting section 41.

[0105] The moving member 136 is movable in the X direction. Specifically, the position adjustment unit 130 has a feed member 142 and a drive source 144, and the feed member 142 moves the moving member 136 in the X direction. In this embodiment, the feed member 142 is a feed screw, which is an example of a screw member. The feed member 142 penetrates a connecting plate 146 that connects the X-direction ends of the pair of support plates 140. The drive source 144 is connected to one axial end of the feed member 142. The drive source 144 drives and rotates the feed member 142. In this embodiment, the drive source 144 is an electric motor, for example, but the present invention is not limited to this configuration. The drive source 144 is attached to a mounting plate 148 that protrudes from the connecting plate 146 to one side in the X direction (the left side in FIG. 11 , or the front side in the device depth direction). In this embodiment, a housing 131 of the position adjustment unit 130 is configured by the pair of support plates 140, the connecting plate 146, and the mounting plate 148. The housing 131 is attached to a frame (not shown) of the image forming unit 14.

[0106] The moving member 136 is provided with a conversion section 150 that converts the moving force in the X direction applied by the feed member 142 into a moving force for moving the shaft member 134 in the light irradiation direction. Specifically, the conversion section 150 is provided at a portion of the moving member 136 that contacts the shaft member 134, and is an inclined surface that is inclined with respect to the X direction. More specifically, as shown in FIG. 12 , the moving member 136 has a pair of conversion sections 150 (a pair of inclined surfaces), and the pair of conversion sections 150 contact both axial sides of the shaft member 134, sandwiching the contact member 132 therebetween. As an example, the moving member 136 of this embodiment is formed in a rectangular parallelepiped shape, and a groove 136A extending in the X direction is formed in a portion corresponding to the contact member 132, into which part of the outer periphery of the contact member 132 fits. The pair of conversion sections 150 are formed on both sides of the shaft member 134, sandwiching the groove 136A therebetween.

[0107] 10 , the base 42 is pressed toward the position adjustment unit 130 by a pressing unit 129 disposed on the opposite side from the position adjustment unit 130. That is, the base 42 is clamped and pressed in the Z direction between the position adjustment unit 130 and the pressing unit 129. When the moving member 136 moves in the X direction, a moving force in the Z direction is applied to the shaft member 134 via the outer peripheral surface of the shaft member 134 by the inclined surface of the converting unit 150. When this moving force in the Z direction is applied to the shaft member 134, it is transmitted from the shaft member 134 via the contact member 132 to the base 42, pushing back the pressing unit 129, and the base 42 moves in the Z direction, i.e., the position is adjusted.

[0108] 12, the feed member 142 that penetrates the movable member 136 and the contact member 132 overlap in the light irradiation direction. Furthermore, as shown in Fig. 11, in this embodiment, as an example, a straight line SL that passes through the contact point between the contact member 132 and the base 42 and the contact point between the movable member 136 and the shaft member 134 is aligned along the light irradiation direction of the light-emitting unit 41.

[0109] Furthermore, the coefficient of friction between the contact member 132 and the base 42 is smaller than the coefficient of friction between the shaft member 134 and the contact member 132. Specifically, in this embodiment, the contact member 132 is a ball bearing, and therefore the contact member 132 rotates relative to the shaft member 134 before friction occurs between the contact member 132 and the base 42.

[0110] Furthermore, the ends of the pair of support plates 140 in the Z direction are connected to each other by a connecting plate 147. An opening 147A is formed in this connecting plate 147, and part of the outer periphery of the contact member 132 protrudes from this opening 147A. Part of the protruding part of the contact member 132 is in contact with the surface 42A of the base 42.

[0111] 15, the position adjustment unit 130 is disposed at a position overlapping the positioning unit 160 when viewed from the X direction. The position adjustment unit 130 is positioned at a position overlapping the positioning unit 160 when viewed from the X direction by contacting the drum flange 33. Specifically, the moving member 136 contacts a block 36 provided on the drum flange 33. In this embodiment, the position adjustment unit 130 is positioned outward in the X direction from the positioning unit 160 (see FIGS. 10 and 13).

[0112] The driving source 144 is disposed on the opposite side of the position adjusting unit 130 in the X direction from the positioning unit 160 side (on the front side in the device depth direction).

[0113] 15, the length L1 in the Y direction of the outer circumferential surface 132A, which is the contact surface of the contact member 132, is shorter than the length L2 in the Y direction of the positioning portion 160. In this embodiment, the pressing portion 129, the contact member 132, and the positioning portion 160 are arranged on the same straight line (straight line SL2 in FIG. 15) that extends along the light irradiation direction when viewed from the X direction. Note that FIG. 15 only illustrates the configuration related to the base 42, the pressing portion 129, the contact member 132, the shaft member 134, the positioning portion 160A, and the restraining portion 34.

[0114] 18, in the light-emitting unit 41 of this embodiment, a measuring device 162 is provided adjacent to the light irradiation unit 44 in the width direction (Y direction) of the base 42. This measuring device 162 is a device that measures the distance from the light-emitting unit 41 to the surface of the photosensitive drum 32. The measuring device 162 is rectangular when viewed from the Z direction, and its long side 162A is aligned with the direction in which the base 42 extends (X direction). The measuring device 162 is disposed near the portion of the base 42 with which the contact member 132 of the adjustment unit 130 comes into contact.

[0115] In the image forming apparatus 10 of this embodiment, measuring devices 162 provided on both ends of the base 42 measure the distance from the light-emitting unit 41 to the surface of the photosensitive drum 32, and the measurement information is sent to a control device (not shown). The control device operates each position adjustment unit 130 based on the measurement information. Specifically, the drive amount of the drive source 144 is adjusted based on the measurement information. When the value measured by the measuring device 162 falls within a preset range, the control device stops the operation of the drive source 144. The position adjustment of the light-emitting unit 41 using the position adjustment unit 130 may be performed when the light-emitting unit 41 is attached to the photosensitive drum 32, or may be performed after a predetermined time (period) has elapsed.

[0116] Next, the operation and effects of this embodiment will be described.

[0117] In the image forming apparatus 10 using the exposure device 40 of this embodiment, the positioning unit 160 and the adjustment unit 130 overlap when viewed from the X direction. Therefore, for example, compared to a configuration in which the positioning unit 160 and the adjustment unit 130 are spaced apart when viewed from the X direction, the size of the photosensitive drum 32 in the direction perpendicular to the axial direction can be reduced.

[0118] In the image forming apparatus 10, the position in the Y direction is determined by the positioning unit 160 coming into contact with the drum flange 33, and the position adjustment unit 130 is positioned so as to overlap with the positioning unit 160 as viewed from the X direction by coming into contact with a block 36 provided on the drum flange 33. Therefore, the positional accuracy of the light emitting unit 41 relative to the photosensitive drum 32 is improved compared to a configuration in which, for example, the positioning unit 160 and the position adjustment unit 130 have different positioning standards.

[0119] In the image forming apparatus 10, the position adjustment unit 130 is located further outward in the X direction than the positioning unit 160, i.e., closer to the front in the device depth direction. Therefore, it is easier to finely adjust the distance between the light-emitting unit 41 and the photosensitive drum 32, for example, compared to a configuration in which the position adjustment unit 130 is located further inward in the X direction than the positioning unit 160 (toward the center in the axial direction of the photosensitive drum 32).

[0120] In the image forming apparatus 10, the driving source 144 is disposed on the opposite side of the position adjustment unit 130 from the positioning unit 160 in the X direction. Therefore, compared to a configuration in which the driving source 144 is disposed on the position adjustment unit 130 side of the positioning unit 160 in the X direction, for example, the driving source 144 is easier to access.

[0121] In the image forming apparatus 10, the length L1 in the Y direction of the outer circumferential surface 132A, which is the contact surface of the contact member 132, is shorter than the length L2 in the Y direction of the positioning portion 160. Therefore, compared to a configuration in which the length L1 of the contact member 132 is longer than the length L2 of the positioning portion 160, for example, it is possible to suppress misalignment of the focus of the light-emitting portion 42 due to the tilt of the position adjustment portion 130.

[0122] In the image forming apparatus 10, the pressing unit 129, the contact member 132, and the positioning unit 160 are all arranged on the same straight line SL2 that extends in the light irradiation direction when viewed from the X direction. Therefore, for example, compared to a configuration in which the pressing unit 129, the contact member 132, and the positioning unit 160 are all arranged on different straight lines when viewed from the X direction, the size of the image forming unit 12 in the direction perpendicular to the X direction can be made smaller.

[0123] In the image forming apparatus 10, the first positioning unit 160A is constrained by the first constraining unit 34A to determine its position in the Y direction, and the second positioning unit 160B is constrained by the second constraining unit 34B to determine its position in the X and Y directions. Therefore, compared to a configuration in which the first positioning unit 160A and the second positioning unit 160B constrain movement in the X and Y directions, for example, distortion of the base body due to the constraints can be suppressed.

[0124] In image forming apparatus 10, second positioning portion 160B is a protrusion, and second constraint portion is a recessed portion into which the protrusion fits, and the portion of the recessed portion that comes into contact with the protrusion in the X direction has an arc shape. Therefore, for example, in image forming apparatus 10, the portion of the recessed portion that comes into contact with the protrusion in the X direction can be more effectively prevented from seizing when the protrusion is tilted than when the portion of the recessed portion that comes into contact with the protrusion in the X direction has an angular shape.

[0125] In the image forming apparatus 10, the measuring device 162 is provided adjacent to the light emitting element in the width direction of the base and with its long side aligned along the extension direction of the base 42. Therefore, for example, compared to a configuration in which the long side of the measuring device 162 is aligned along the width direction of the base 42, the measuring device can be positioned at the center of the width direction (Y direction) of the base 42.

[0126] In the image forming apparatus 10, the measuring device 162 is disposed at a position within the Y-direction width of the base 42 that is closer to the Y-direction position of the portion where the position adjustment unit 130 contacts the base 42 than to the Y-direction end portion of the base 42. In other words, the measuring device 162 is disposed near the portion where the position adjustment unit 130 contacts the base 42. Therefore, for example, it is easier to fine-tune the distance between the light-emitting unit 41 and the photosensitive drum 32 compared to a configuration in which the measuring device 162 is disposed at a position away from the portion where the contact member 132 of the position adjustment unit 130 contacts the base 42.

[0127] In the image forming apparatus of the above-described embodiment, three light-emitting units are arranged on the base, but the present invention is not limited to this configuration. For example, one light-emitting unit, two light-emitting units, or four or more light-emitting units may be arranged on the base. Furthermore, the positions of the multiple light-emitting units arranged on the base can be set appropriately.

[0128] Furthermore, in the image forming apparatus of the above-described embodiment, the base is configured as a metal block, but the present invention is not limited to this. The material or shape of the base can be changed. For example, the base may be configured as a resin or as another metal material such as sheet metal. Furthermore, the components of the light-emitting unit or the shape of the components of the light-emitting unit can be changed. Although the support of the light-emitting unit is configured as a metal block, the present invention is not limited to this. The material or shape of the support can be changed. For example, the support may be configured as a resin or as another metal material such as sheet metal.

[0129] Furthermore, the image forming apparatus of the above-described embodiment can be used for applications involving components to which photolithography is applied, such as forming color filters in the manufacturing process of liquid crystal displays (LCDs), exposing dry film resist (DFR) in the manufacturing process of thin film transistors (TFTs), exposing dry film resist (DFR) in the manufacturing process of plasma display panels (PDPs), exposing photosensitive materials such as photoresist in the manufacturing process of semiconductor elements, exposing photosensitive materials such as photoresist in the platemaking process of printing other than offset printing, such as gravure printing, or exposing photosensitive materials in the manufacturing process of watch parts. Here, photolithography refers to a technique for generating a pattern consisting of exposed and unexposed areas by exposing the surface of a material on which a photosensitive material is disposed in a pattern.

[0130] The image forming device can use either a photon mode photosensitive material, in which information is recorded directly by exposure, or a heat mode photosensitive material, in which information is recorded by heat generated by exposure. The light source of the image forming device can be an LED element or a laser element, depending on the object to be exposed.

[0131] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that the present invention is not limited to such embodiments, and that various other embodiments are possible within the scope of the present invention. [Explanation of symbols]

[0132] 10 Image forming device 32 Photosensitive drum (an example of an image-holding member) 34 Restraint part 40 Exposure equipment 41 Light-emitting part 42 Base 129 Pressing part (an example of a pressing member) 130 Position adjustment unit (an example of an adjustment unit) 132 Contact member 33 Support member (drum flange) 160 Positioning part 162 Measuring Instruments SL2 straight line

Claims

1. an image carrier extending in one direction; a light-emitting section including a substrate extending in one direction and a plurality of light-emitting elements disposed on the substrate and configured to irradiate the image carrier with light; a positioning unit disposed between the substrate and the image carrier, the positioning unit determining a position relative to the image carrier in a direction perpendicular to the light irradiation direction of the light emitting unit; an adjustment unit that is arranged at a position overlapping with the positioning unit when viewed from the one direction and adjusts the position of the light emitting unit in the light irradiation direction; Equipped with the positioning portion has a first positioning portion provided on one end side in the extension direction of the base body and a second positioning portion provided on the other end side in the extension direction of the base body, the first positioning unit is constrained by a first constraining unit of the image carrier to determine a position in a width direction of the substrate among the orthogonal directions; The second positioning section is constrained by a second constraining section of the image carrier to determine a position in the extending direction of the substrate and in a width direction of the substrate, among the orthogonal directions.

2. a support member attached to the apparatus body and rotatably supporting the image carrier; the positioning portion is positioned in the orthogonal direction relative to the image carrier by contacting the support member, The image forming apparatus according to claim 1 , wherein the adjustment portion is positioned at a position where it comes into contact with the support member and overlaps with the positioning portion when viewed from an axial direction of the image carrier that is parallel to the one direction.

3. 3. The image forming apparatus according to claim 1, wherein the adjustment unit is positioned further outward in the axial direction of the image carrier than the positioning unit.

4. the adjustment unit has a drive source that moves the light-emitting unit, The image forming apparatus according to claim 3 , wherein the drive source is disposed on the side of the adjustment unit opposite to the positioning unit in the axial direction of the image carrier.

5. the positioning portion is a protrusion that protrudes from the base toward the support member and is fitted into a recessed portion provided in the support member, the adjustment unit has a contact member that comes into contact with the base and moves the base in the light irradiation direction, The image forming apparatus according to claim 2, claim 3 that relies on claim 2, or claim 4 that relies on claim 2, wherein the length of the contact surface of the contact member in the perpendicular direction is shorter than the length of the protrusion in the perpendicular direction.

6. a pressing member disposed on the opposite side of the base from the adjustment unit and configured to press the base toward the contact member; 6. The image forming apparatus according to claim 5, wherein the pressing member, the contact member, and the protrusion are arranged on the same straight line extending in the light irradiation direction when viewed from the one direction.

7. the second positioning portion is a protrusion provided on the base, the second restraint portion is a recessed portion into which the protrusion fits, 2. The image forming apparatus according to claim 1, wherein the recessed portion has an arc-shaped portion that contacts the protrusion in the extending direction of the image carrier.

8. a measuring device provided adjacent to the light-emitting element in the width direction of the base, the measuring device measuring the distance from the light-emitting unit to the outer peripheral surface of the image carrier; 8. The image forming apparatus according to claim 1, wherein the measuring device is rectangular when viewed from the light irradiation direction, and a long side of the measuring device is aligned with the extending direction of the base.

9. 9. The image forming apparatus according to claim 8, wherein the measuring device is disposed in the vicinity of a portion of the base with which the adjustment section comes into contact.

10. a light-emitting section including a substrate extending in the same direction as an image carrier extending in one direction, and a plurality of light-emitting elements disposed on the substrate and irradiating the image carrier with light; a positioning unit disposed between the substrate and the image carrier, the positioning unit determining a position relative to the image carrier in a direction perpendicular to the light irradiation direction of the light emitting unit; an adjustment unit that is arranged at a position overlapping with the positioning unit when viewed from the one direction and adjusts the position of the light emitting unit in the light irradiation direction; Equipped with the positioning portion has a first positioning portion provided on one end side in the extension direction of the base body and a second positioning portion provided on the other end side in the extension direction of the base body, the first positioning unit is constrained by a first constraining unit of the image carrier to determine a position in a width direction of the substrate among the orthogonal directions; an exposure device in which the second positioning section is constrained by a second constraining section of the image carrier to determine a position in the extending direction of the substrate and in a width direction of the substrate, among the orthogonal directions;

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