Lighting device and drawing device

Abstract

The light emitting device (40) comprises: a base (42) extending in one direction; a light emitting portion (44) in which a plurality of light sources (64) arranged along one direction are supported on a support (60), the support (60) being composed of a metal block extending in one direction; a spacer (56) sandwiched between the base (42) and the light emitting portion (44) in the direction of the optical axis of the light source (64); and a fastening member (58) fixing the light emitting portion (44) to the base (42) in such a manner that a compressive load is applied to the spacer (56).

Description

Technical Field

[0001] The present invention relates to a light emitting device and a drawing device. Background Art

[0002] The following patent document 1 discloses an exposure device, which has a first exposure head and a second exposure head, the first exposure head having: a plurality of first light-emitting elements, which are arranged in a first direction and emit first lights respectively; a first optical system, which is arranged opposite to the plurality of first light-emitting elements in a second direction intersecting the first direction, so that the plurality of first lights respectively emitted from the plurality of first light-emitting elements are imaged respectively; a first joint; and a first substrate, which supports the plurality of first light-emitting elements, the first optical system and the first joint, the second exposure head having: a plurality of second light-emitting elements, which are arranged in the first direction and emit second lights respectively; a second optical system, which is arranged opposite to the plurality of second light-emitting elements in the second direction, so that the plurality of second lights respectively emitted from the plurality of second light-emitting elements are imaged respectively; a second joint, which is engaged with the first joint; and a second substrate, which supports the plurality of second light-emitting elements, the second optical system and the second joint. In the exposure device, the first joint is arranged at a first position in the first base corresponding to an imaging position of the first optical system, and the second joint is arranged at a second position in the second base corresponding to an imaging position of the second optical system.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-177664 Summary of the invention

[0006] Problems to be solved by the invention

[0007] An object of the present invention is to obtain a light emitting device and a drawing device in which focus deviation caused by the position of the light emitting portion in one direction is suppressed compared with a case where the light emitting portion is fixed to a base in a manner that the light emitting portion is in direct contact with the base.

[0008] Means for solving problems

[0009] The light-emitting device of the first mode comprises: a base extending in one direction; a light-emitting portion in which a plurality of light sources arranged along the one direction are supported on a support, the support being composed of a metal block extending in the one direction; a spacer sandwiched between the base and the light-emitting portion in the direction of the optical axis of the light source; and a fixing portion fixing the light-emitting portion to the base in such a manner that a compressive load is applied to the spacer.

[0010] A light emitting device according to a second aspect is the light emitting device according to the first aspect, wherein at least two of the spacers are arranged at intervals in the one direction.

[0011] A light emitting device according to a third aspect is the light emitting device according to the second aspect, wherein the spacers are arranged at both ends of the support body in the one direction.

[0012] Regarding a light emitting device according to a fourth aspect, in the light emitting device according to the second aspect or the third aspect, at least three of the spacers are arranged at intervals in the one direction.

[0013] Regarding the light emitting device of the fifth aspect, in the light emitting device described in any one of the second to fourth aspects, the plurality of light emitting parts are fixed to the base by the fixing part in a state where the spacer is sandwiched between the plurality of light emitting parts and the base.

[0014] Regarding a light emitting device according to a sixth aspect, in the light emitting device according to the fifth aspect, the plurality of light emitting portions are arranged to be staggered in the one direction.

[0015] Regarding a light emitting device according to a seventh aspect, in the light emitting device according to any one of the first to sixth aspects, the fixing portion includes a fastening member that penetrates the spacer.

[0016] Regarding the light emitting device of an eighth aspect, in the light emitting device described in the seventh aspect, the spacer can be inserted and removed between the base and the support body in a state where the fastening member is loosened.

[0017] Regarding a light emitting device according to a ninth aspect, in the light emitting device described in the eighth aspect, the spacer is in a plate shape.

[0018] Regarding a light emitting device according to a tenth aspect, in the light emitting device according to the ninth aspect, the spacer has a U-shape when viewed from the optical axis direction.

[0019] Regarding the light emitting device of the eleventh aspect, in the light emitting device described in any one of the first aspect to the tenth aspect, the base is provided with a recessed portion into which the spacer enters, and the bottom surface of the recessed portion is a cut surface.

[0020] Regarding the light emitting device of aspect 12, in the light emitting device described in any one of aspects 8 to 10, a recess into which the spacer enters is provided in the base, and the recess has no wall on at least one side in the short side direction of the base.

[0021] Regarding the light emitting device of aspect 13, in the light emitting device described in any one of aspects 1 to 12, a recess for the spacer to enter is provided in the base, and the bottom surface of the recess is an inclined surface inclined relative to the front surface of the base.

[0022] Regarding the light-emitting device of the 14th embodiment, in the light-emitting device described in the 13th embodiment, the plurality of light-emitting portions are staggered in the short side direction of the substrate, and the inclined surface corresponding to the light-emitting portion arranged on one side in the short side direction and the inclined surface corresponding to the light-emitting portion arranged on the other side in the short side direction are inclined in the opposite directions.

[0023] Regarding the light emitting device of aspect 15, in the light emitting device described in aspect 13 or 14, the spacer having a thickness equal to or greater than a depth of the recess is arranged on the inclined surface.

[0024] Regarding a light emitting device according to a sixteenth aspect, in the light emitting device according to any one of the first to fifteenth aspects, the base is made of a metal block, and the spacer is made of a material having a higher thermal conductivity than polyacetal resin.

[0025] Regarding a light emitting device according to a seventeenth aspect, in the light emitting device according to the sixteenth aspect, the spacer forms a heat dissipation path for dissipating heat from the support body to the base body.

[0026] Regarding the light-emitting device of the 18th aspect, in the light-emitting device described in any one of the 1st aspect to the 17th aspect, there is a concave portion cut toward the spacer side on the surface of the base opposite to the spacer, and the light-emitting portion is fixed to the base from the inside of the concave portion by using a fastening part constituting the fixing portion.

[0027] Regarding the drawing device of the 19th mode, it comprises: a light-emitting device as described in any one of the 1st to 18th modes; and an area where a photosensitive material is configured, which moves relative to the light-emitting device in a direction intersecting the one direction and is irradiated by light from the light-emitting device.

[0028] Regarding the drawing device of the 20th aspect, in the drawing device described in the 19th aspect, the region is provided on the surface of a cylindrical member rotating in the circumferential direction.

[0029] Effects of the Invention

[0030] According to the light emitting device of the first aspect, compared with the case where the light emitting unit is fixed to the base body so that the light emitting unit is in direct contact with the base body, focus deviation caused by the position of the light emitting unit in one direction is suppressed.

[0031] According to the light emitting device of the second aspect, compared with the case where the spacer is arranged at one location of the light emitting portion, the inclination of the light emitting portion can be adjusted.

[0032] According to the light emitting device of the third aspect, the accuracy of adjusting the inclination of the light emitting portion is improved compared to the case where the spacer is arranged on the central portion side of the support body.

[0033] According to the light emitting device of the fourth aspect, the light emitting portion can be adjusted to a curved shape, compared to a case where two spacers are arranged at intervals in one direction of the light emitting portion.

[0034] According to the light emitting device of the fifth aspect, in the structure in which the plurality of light emitting parts are provided on the base, focus deviation among the plurality of light emitting parts is suppressed.

[0035] According to the light emitting device of the sixth aspect, compared with a case where a plurality of light emitting units are arranged in parallel on a base, light can be irradiated over a longer range in one direction.

[0036] According to the light emitting device of the seventh aspect, compared with a case where the spacer is arranged at a position different from the fastening member, the mounting portion of the spacer can be made more compact.

[0037] According to the light emitting device of the eighth aspect, the focus deviation adjustment operation is easier to perform compared to the case where the light emitting unit is removed from the base body when inserting and removing the spacer.

[0038] According to the light emitting device of the ninth aspect, heat dissipation from the light emitting portion to the base is facilitated compared to a case where the spacer is a coil spring.

[0039] According to the light emitting device of the tenth aspect, the structure of the spacer becomes simpler compared to the case where the spacer is a divided type.

[0040] According to the light emitting device of the eleventh aspect, the adjustment accuracy of the focus deviation is improved compared to the case where the spacer is arranged on the front surface of the outer side of the base.

[0041] According to the light emitting device of the twelfth aspect, compared with a case where a wall is provided around the recessed portion, insertion and removal of the spacer are facilitated.

[0042] According to the light emitting device of the thirteenth aspect, compared with a case where the bottom surface of the recessed portion is parallel to the front surface of the base, the irradiated light is irradiated perpendicularly to the circular irradiation target surface.

[0043] According to the light emitting device of the fourteenth aspect, compared with a case where the inclined directions of the inclined surfaces of the plurality of light emitting portions are the same, the irradiated light is irradiated perpendicularly to the circular irradiation target surface.

[0044] According to the light emitting device of the fifteenth aspect, compared with a case where a spacer having a thickness smaller than the depth of the recessed portion is arranged, interference between the front surface of the base and the light emitting portion is suppressed.

[0045] According to the light emitting device of the sixteenth aspect, heat dissipation from the light emitting portion is improved compared to a case where the base or the spacer is made of polyacetal resin.

[0046] According to the light emitting device of the seventeenth aspect, heat dissipation from the light emitting portion is improved compared to a case where the spacer is formed of a heat insulating portion.

[0047] According to the light emitting device of the eighteenth aspect, compared with the case where the light emitting portion is fixed to the plate-shaped portion of the base body by a fastening member, it is possible to fix the light emitting portion by a fastening member having a shorter length without reducing the thickness of the entire base body.

[0048] According to the drawing device of the nineteenth aspect, compared with a case where the light emitting section is fixed to the base body in such a manner that the light emitting section is in direct contact with the base body, a decrease in image quality during drawing is suppressed.

[0049] According to the drawing device of the twentieth aspect, in the configuration in which light is irradiated to the surface area of ​​the cylindrical member, degradation of image quality during drawing is suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a schematic diagram showing an image forming apparatus including an exposure device according to a first embodiment.

[0051] Figure 2 It is a perspective view showing an exposure device used in the image forming apparatus.

[0052] Figure 3 It is a structural diagram showing the exposure device in a state viewed from the top and bottom.

[0053] Figure 4 This is a perspective view in which a part of the exposure device is enlarged.

[0054] Figure 5 It is a perspective view showing a spacer of the exposure device.

[0055] Figure 6 It is an enlarged perspective view showing a spacer of the exposure device.

[0056] Figure 7 It is a figure which shows a part of an exposure apparatus, and is a cross-sectional view which shows a spacer.

[0057] Figure 8 This is a perspective view showing the exposure device in a state where the exposure device is cut along a direction perpendicular to the longitudinal direction.

[0058] Fig. 9It is a perspective view showing a concave portion in which a spacer is arranged in a base body of an exposure device.

[0059] Fig.10 This is a perspective view showing a state where a spacer is arranged in a partial recessed portion of a base body of the exposure device.

[0060] Fig.11 This is a perspective view showing a state where a fastening member is inserted through a spacer of an exposure device.

[0061] Fig.12 This is a diagram showing the structure of a drawing device having a light emitting device according to a second embodiment.

[0062] Fig.13 It is a side view showing a part of the light emitting device of the first comparative example.

[0063] Fig.14 It is a cross-sectional view showing a part of the light emitting device of the second comparative example. DETAILED DESCRIPTION

[0064] Next, a mode for carrying out the present invention (hereinafter referred to as the present embodiment) will be described.

[0065] [First embodiment]

[0066] <Image Forming Apparatus 10>

[0067] Figure 1 1 is a schematic diagram showing the structure of an image forming apparatus 10 having an exposure device 40 according to a first embodiment. First, the structure of the image forming apparatus 10 is described. Next, the exposure device 40 used in the image forming apparatus 10 is described. Here, the image forming apparatus 10 is an example of a drawing apparatus, and the exposure device 40 is an example of a light emitting device. As an example, the image forming apparatus 10 is an image forming apparatus that forms an image using multiple colors, such as a full-color printer for commercial printing that particularly requires high image quality.

[0068] The image forming apparatus 10 is a wide-format image forming apparatus that supports a width exceeding the width of the recording medium P when B3 is longitudinally fed (i.e., a width exceeding 364 mm). As an example, the image forming apparatus 10 supports a recording medium P having a size of 420 mm or more when A2 is longitudinally fed and 1456 mm or less when B0 is transversely fed. For example, the image forming apparatus 10 supports a size of 728 mm when B2 is transversely fed.

[0069] Figure 1The image forming device 10 shown is an example of an image forming device that forms an image on a recording medium. Specifically, the image forming device 10 is an electronic photographic image forming device that forms a toner image (an example of an image) on a recording medium P. Toner is an example of a powder. More specifically, the image forming device 10 includes an image forming unit 14 and a fixing device 16. Next, each unit (the image forming unit 14 and the fixing device 16) of the image forming device 10 will be described.

[0070] <Image Forming Unit 14>

[0071] The image forming section 14 has a function of forming a toner image on the recording medium P. Specifically, the image forming section 14 includes a toner image forming section 22 and a transfer device 17 .

[0072] <Toner Image Forming Section 22>

[0073] Figure 1 The toner image forming units 22 shown are provided in plurality so as to form toner images for each color. In the present embodiment, toner image forming units 22 for a total of four colors, namely yellow (Y), magenta (M), cyan (C), and black (K) are provided. Figure 1 The (Y), (M), (C), and (K) shown represent the structural parts corresponding to the above-mentioned colors.

[0074] The toner image forming units 22 of each color are configured in the same manner except for the toner used. Therefore, the toner image forming units 22 of each color are represented by Figure 1 In FIG. 1 , each component of the toner image forming section 22 (K) is denoted by a reference numeral.

[0075] Specifically, the toner image forming section 22 of each color has a toner image forming section 22 extending in one direction (for example, Figure 1 The photosensitive drum 32 rotates in the counterclockwise direction (in the direction of rotation). Here, the photosensitive drum 32 is an example of a cylindrical member, and the photosensitive body on the surface of the photosensitive drum 32 is an example of a region where a photosensitive material is arranged. In addition, the toner image forming unit 22 of each color includes a charger 23, an exposure device 40, and a developing device 38.

[0076] In the toner image forming section 22 of each color, the charger 23 charges the photosensitive drum 32. Then, the exposure device 40 exposes the photosensitive drum 32 charged by the charger 23 to form an electrostatic latent image on the photosensitive drum 32. The developing device 38 develops the electrostatic latent image formed on the photosensitive drum 32 by the exposure device 40 to form a toner image.

[0077] The photosensitive drum 32 rotates while holding the electrostatic latent image formed as described above on its outer circumference, and the electrostatic latent image is transported to the developing device 38. The specific structure of the exposure device 40 will be described later.

[0078] <Transfer Device 17>

[0079] Figure 1 The transfer device 17 shown in the figure is a device for transferring the toner image formed by the toner image forming unit 22 onto the recording medium P. Specifically, the transfer device 17 transfers the toner image of each color of the photosensitive drum 32 to the transfer belt 24 as an intermediate transfer body, and transfers the overlapped toner image to the recording medium P for the second time. Specifically, as shown in FIG. Figure 1 As shown, the transfer device 17 has a transfer belt 24 , a primary transfer roller 26 , and a secondary transfer roller 28 .

[0080] The primary transfer roller 26 is a roller that transfers the toner image of each color of the photosensitive drum 32 onto the transfer belt 24 at the primary transfer position T1 between the photosensitive drum 32 and the primary transfer roller 26. In the present embodiment, a primary transfer electric field is applied between the primary transfer roller 26 and the photosensitive drum 32, whereby the toner image formed on the photosensitive drum 32 is transferred onto the transfer belt 24 at the primary transfer position T1.

[0081] The toner image is transferred from the photosensitive drum 32 of each color to the outer peripheral surface of the transfer belt 24. Specifically, the transfer belt 24 is constructed as follows. Figure 1 As shown, the transfer belt 24 is in an endless shape and is wound around a plurality of rollers 39 so that its posture is determined.

[0082] For example, the driving roller 39D among the plurality of rollers 39 is driven to rotate by a driving unit (not shown), whereby the transfer belt 24 is looped in the direction of arrow A. Figure 1 The roller 39B shown is an opposing roller 39B that opposes the secondary transfer roller 28 .

[0083] The secondary transfer roller 28 is a roller that transfers the toner image transferred onto the transfer belt 24 onto the recording medium P at the secondary transfer position T2 between the opposing roller 39B and the secondary transfer roller 28. In the present embodiment, a secondary transfer electric field is applied between the opposing roller 39B and the secondary transfer roller 28, whereby the toner image transferred onto the transfer belt 24 is transferred onto the recording medium P at the secondary transfer position T2.

[0084] <Fixing Device 16>

[0085] Figure 1 The fixing device 16 shown in the figure is a device that fixes the toner image transferred onto the recording medium P by the secondary transfer roller 28 to the recording medium P. Specifically, Figure 1As shown, the fixing device 16 includes a heating roller 16A as a heating member and a pressure roller 16B as a pressure member. In the fixing device 16, the recording medium P is heated and pressed by the heating roller 16A and the pressure roller 16B, thereby fixing the toner image formed on the recording medium P to the recording medium P.

[0086] <Exposure Device 40>

[0087] Next, the structure of the exposure device 40 which is the main part of this embodiment is demonstrated. Figure 2 It is a perspective view showing the structure of the exposure device 40. Figure 3 1 is a top view showing the exposure device 40 when viewed from the top and bottom. In the following description, the arrow X direction shown in the figure is set as the width direction of the exposure device 40, and the arrow Y direction is set as the height direction of the exposure device 40. The arrow Z direction orthogonal to the device width direction and the device height direction is set as the depth direction of the exposure device 40. The above-mentioned width direction and height direction are directions set for convenience of description, and therefore the structure of the exposure device 40 is not limited to these directions.

[0088] First, the overall structure of the exposure device 40 will be described, and then each component of the exposure device 40 will be described.

[0089] (Overall Structure of Exposure Device 40)

[0090] like Figure 2 and Figure 3 As shown, the exposure device 40 includes a base 42 extending in one direction (in the arrow Z direction in this embodiment) and a substrate 42 disposed on one side of the base 42 in the arrow Y direction (in the arrow Y direction). Figure 2 and Figure 3 In the present embodiment, three light emitting portions 44 extending in one direction of the base 42 are provided. Figure 3 The light emitting parts 44 have the same structure. Figure 3 The light emitting portion 44 is a long rectangular member in a plan view. The length of the light emitting portion 44 in one direction (ie, the longitudinal direction) is shorter than the length of the base 42 in one direction (ie, the longitudinal direction).

[0091] As an example, the three light emitting units 44 are arranged staggered in one direction (arrow Z direction) of the base 42, and are arranged staggered in the width direction orthogonal to the one direction of the base 42, that is, the short side direction (arrow X direction) of the base 42. The exposure device 40 is arranged along the photosensitive drum 32 (refer to Figure 1), and the length of the exposure device 40 in one direction (arrow Z direction) is greater than the axial length of the photosensitive drum 32. Any one or more of the three light emitting portions 44 are opposite to the area on the surface of the photosensitive drum 32 where the photosensitive body is provided. Thus, the light emitted from the exposure device 40 is irradiated to the surface of the photosensitive drum 32.

[0092] exist Figure 2 and Figure 3 In the exposure device 40 shown in FIG. 1 , the side of the base 42 provided with the light emitting section 44 is shown as the upper side in the vertical direction, and light is irradiated from the light emitting section 44 toward the upper side, but in FIG. Figure 1 In the image forming apparatus 10 shown in FIG. 1 , the exposure device 40 is arranged in the opposite vertical direction. Figure 1 In the figure, the exposure device 40 is arranged such that the side of the base 42 provided with the light emitting section 44 is on the lower side in the vertical direction, and light is irradiated from the light emitting section 44 toward the photosensitive drum 32 on the lower side.

[0093] In the present embodiment, the three light emitting units 44 are arranged in a staggered manner when viewed from the upper side in the vertical direction of the exposure device 40 (see FIG. Figure 3 ). More specifically, two light emitting portions 44 are arranged on one side in the short side direction (arrow X direction) of the substrate 42 at both end sides in one direction (arrow Z direction) of the substrate 42. One light emitting portion 44 is arranged on the other side in the short side direction (arrow X direction) of the substrate 42 at the central portion in one direction (arrow Z direction) of the substrate 42. When viewed from the short side direction (arrow X direction) of the substrate 42, the ends of the two light emitting portions 44 arranged on one side in the short side direction (arrow X direction) of the substrate 42 overlap with the end of the one light emitting portion 44 arranged on the other side in the short side direction (arrow X direction) of the substrate 42. That is, in one direction (arrow Z direction) of the substrate 42, a portion of the irradiation range of light from the three light emitting portions 44 overlaps.

[0094] When viewed from one direction of the base 42 (arrow Z direction), the two light emitting portions 44 arranged on one side of the short side direction of the base 42 (arrow X direction) do not overlap with the one light emitting portion 44 arranged on the other side of the short side direction of the base 42 (arrow X direction).

[0095] like Figure 2 and Figure 4 As shown in FIG. 1 , the exposure device 40 includes a harness 46 electrically connected to each of the three light emitting units 44, a plurality of brackets 48 supporting the harness 46, and a lower cover 50 covering the harness 46 and the brackets 48 from the outside. The brackets 48 are mounted on the base 42 and extend from the base 42 to the other side in the direction of arrow Y (at the bottom of the base 42). Figure 2 The lower cover 50 is attached to the other side of the base 42 in the direction of arrow Y (in the vertical direction). Figure 2 The middle is the lower side in the up-down direction).

[0096] like Figure 2 and Figure 3 As shown, the exposure device 40 has a side cover 52 covering the sides of the three light emitting units 44. The side cover 52 is plate-shaped, and its lower end side is attached to both sides of the short side direction (arrow X direction) of the base 42. The exposure device 40 has a cleaning device 54 for cleaning the lens unit 68 described later of the light emitting unit 44.

[0097] And, if Figures 5 to 8 As shown, the exposure device 40 includes a plurality of spacers 56 and a fastening member 58, wherein the plurality of spacers 56 are sandwiched between the base 42 and the light emitting unit 44, and the fastening member 58 is an example of a fixing member, and fixes the light emitting unit 44 to the base 42 in a state where the plurality of spacers 56 are sandwiched. The fastening member 58 is, for example, a member having a spiral groove and fastening through the groove. In other words, the fastening member 58 is a member having a threaded mechanism, such as a screw, a bolt, a screw, etc.

[0098] Although not shown in the figure, positioning shafts extending upward and downward are provided at both ends of the base 42 in one direction (arrow Z direction). The positioning shafts contact the bearing members provided at both ends of the photosensitive drum 32, thereby positioning the exposure device 40 relative to the photosensitive drum 32 in the irradiation direction.

[0099] (Base 42)

[0100] like Figures 5 to 8 As shown in FIG. 1 , the base 42 is composed of a rectangular elongated member. The base 42 is arranged on the photosensitive drum 32 ( Figure 1 ) is located at a position opposite to the entire axial length of the substrate 42. A recess 80 for the spacer 56 to enter is provided on the front face 42A on the upper side in the up-down direction (arrow Y direction) of the substrate 42. As an example, for one light emitting portion 44, three spacers 56 are arranged at intervals in one direction (arrow Z direction). That is, three spacers 56 are arranged for each of the three light emitting portions 44 (a total of nine spacers 56). Therefore, nine recesses 80 for the nine spacers 56 to enter are provided on the substrate 42.

[0101] In this embodiment, if Figure 5 As shown, three recesses 80 are arranged at a position located in the center of the base 42 in one direction (arrow Z direction) and opposite to a light emitting portion 44 on the other side of the short side direction (arrow X direction) of the base 42. Figure 5Although not shown in the figure, three recesses 80 are also arranged at the positions opposite to the two light emitting portions 44 on one side of the substrate 42 in the short side direction (arrow X direction) at both end sides of the substrate 42 in one direction (arrow Z direction). Fig. 9 As shown, the shapes of the six recesses 80 arranged on one side of the short side direction (arrow X direction) of the base 42 and the shapes of the three recesses 80 arranged on the other side of the short side direction (arrow X direction) of the base 42 are symmetrical in the short side direction (arrow X direction) of the base 42.

[0102] The recessed portion 80 includes an inclined surface 80A constituting a bottom surface and inclined relative to the front surface 42A of the base 42, a vertical wall 80B disposed at an end portion of the inclined surface 80A in the downward direction, and two vertical walls 80C formed along the inclined surface 80A and disposed opposite to each other (see Fig. 9 ).exist Fig. 9 In the figure, only one vertical wall 80C is observed. The inclined surface 80A is inclined in the short-side direction (arrow X direction) of the base 42. The end of the inclined surface 80A in the downward direction is connected to the vertical wall 80B, and the end of the inclined surface 80A in the upward direction is connected to the front surface 42A of the base 42. That is, the recessed portion 80 has no wall on the end side in the short-side direction of the base 42.

[0103] As an example, the inclined surface 80A corresponding to the two light emitting portions 44 arranged on one side in the short side direction of the base 42 and the inclined surface 80A corresponding to the one light emitting portion 44 arranged on the other side in the short side direction of the base 42 are inclined in opposite directions. In the present embodiment, the inclined surface 80A is inclined downward from the end side in the short side direction (X direction) of the base 42 toward the central part side. The inclined surface 80A on one side in the short side direction of the base 42 and the inclined surface 80A on the other side in the short side direction of the base 42 are symmetrical in the short side direction of the base 42, that is, they are at the same angle relative to the front side 42A of the base 42. In the exposure device 40, the inclined surface 80A is used to adjust from the two light emitting portions 44 arranged on one side in the short side direction of the base 42 and the one light emitting portion 44 arranged on the other side in the short side direction of the base 42 toward the photosensitive drum 32 (refer to Figure 1 In other words, when the exposure device 40 is positioned relative to the photosensitive drum 32, the inclined surface 80A is inclined so that the optical axis of the light emitting portion 44 arranged on one side in the short side direction of the base 42 and the optical axis of the light emitting portion 44 arranged on the other side in the short side direction of the base 42 intersect at the rotation center of the photosensitive drum 32.

[0104] In the present embodiment, the base 42 is composed of a metal block. The metal block in the present embodiment does not include a general sheet metal formed into a shape by bending, but refers to a block of metal having a thickness that is substantially impossible to be bent in the shape of the base used as the exposure device 40. As an example, the metal block is a block of metal having a thickness of 10% or more relative to the width of the base 42. Furthermore, the metal block may be composed of a block of metal having a thickness of 20% or more and 100% or less relative to the width of the base 42.

[0105] Conventional wide-format image forming apparatuses are used to output black-and-white images that do not require high image quality compared to full-color printers for commercial printing, and use sheet metal as a base. On the other hand, the image forming apparatus 10 of this embodiment is a full-color printer for commercial printing, which requires high image quality. Therefore, in order to suppress the influence of the deflection of the base 42 on the image quality, a metal block with higher rigidity than sheet metal is used.

[0106] The base 42 is made of, for example, steel or stainless steel. Here, the base 42 may also be made of a metal block other than steel or stainless steel. For example, aluminum, which has a higher thermal conductivity than steel or stainless steel and is lightweight, may also be used. However, in this embodiment, the heat generated by the light source 64 is mainly dissipated by the support 60. Therefore, in the base 42, rigidity is given priority over thermal conductivity and weight, and steel or stainless steel is used.

[0107] The recessed portion 80 is formed by cutting the base 42, and the inclined surface 80A is a cut surface. In the conventional base made of sheet metal, the inclined surface is formed by bending, but in the metal block of the present embodiment, the inclined surface 80A is formed by cutting. Since the inclined surface 80A is formed by cutting, a higher surface accuracy is ensured compared with the case of sheet metal, thereby becoming a structure that is easy to achieve high image quality compared with the case of sheet metal. The surface accuracy of the inclined surface 80A is higher than the surface accuracy of the front surface 42A of the base 42. Here, the surface accuracy refers to the shape error of the processed surface relative to the ideal surface.

[0108] The thickness of the base 42 in the vertical direction (arrow Y direction) is preferably greater than the thickness of the support body 60 constituting the light emitting portion 44. Thus, the rigidity of the base 42 (bending rigidity in the arrow Y direction) is greater than the rigidity of the light emitting portion 44. The thickness of the base 42 in the vertical direction (arrow Y direction) is preferably 5 mm or more, more preferably 10 mm or more, and further preferably 20 mm or more.

[0109] like Figure 7 and Figure 8As shown, a concave portion 82 is formed on the back surface 42B on the opposite side of the front surface 42A of the base 42 by cutting toward the spacer 56 side, that is, the concave portion 80 side. Here, the back surface 42B of the base 42 is an example of a surface on the opposite side of the spacer 56. The concave portions 82 are respectively provided at positions of the base 42 corresponding to the concave portions 80.

[0110] The concave portion 82 is formed along an inclined direction from the back side 42B of the base 42 toward the central portion side in the short side direction (X direction) of the base 42. As an example, the bottom surface 82A of the concave portion 82 and the inclined surface 80A are consistent in inclination angle relative to the front side 42A of the base 42. That is, at the bottom surface 82A, the thickness of the base 42 in the up and down direction is the same. For example, the concave portion 82 is elliptical when observed from the back side 42B of the base 42. The inner diameter of the concave portion 82 is larger than the outer shape of the head 58A of the fastening member 58. A through hole 84 is provided on the bottom surface 82A of the concave portion 82 for the shaft portion 58B of the fastening member 58 to penetrate the base 42. The through hole 84 opens on the inclined surface 80A of the concave portion 80.

[0111] (Light emitting unit 44)

[0112] The structures of the three light emitting parts 44 are the same. As an example, the two light emitting parts 44 on one side of the short side direction (arrow X direction) of the base 42 and the one light emitting part 44 on the other side of the short side direction (arrow X direction) of the base 42 are arranged symmetrically in the short side direction (arrow X direction) of the base 42.

[0113] like Figure 7 and Figure 8 As shown, the light emitting portion 44 has a support body 60 extending in one direction (arrow Z direction), and a light emitting element substrate 62 supported on a surface (the upper surface in this embodiment) on the opposite side of the base body 42 in the up-down direction (arrow Y direction) of the support body 60. A plurality of light sources 64 arranged along one direction are provided on the light emitting element substrate 62. In this embodiment, the light source 64 is configured to include a plurality of light emitting elements, for example. 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 emitting element array as the light source 64 is arranged in a staggered manner along one direction on the light emitting element substrate 62. The light source 64 may not be a light emitting element array, but a single light emitting element. Each light emitting element is composed of a light emitting diode, a light emitting thyristor, a laser element, etc., and has a resolution of 2400dpi, for example, when arranged in one direction. The light emitting element substrate 62 is a substrate for making any one or more of the plurality of light sources 64 emit light. In Figure 7 In FIG. 1 , only one light source 64 provided in the light emitting unit 44 is shown, and illustration of other light sources is omitted.

[0114] The light emitting portion 44 includes a pair of mounting portions 66 provided on the surface of the light emitting element substrate 62 on the opposite side to the support body 60 , and a lens portion 68 held in a state of being sandwiched between upper ends of the pair of mounting portions 66 .

[0115] The pair of mounting portions 66 and the lens portion 68 extend along one direction (arrow Z direction) of the support body 60 (see Figure 4 The lens portion 68 is disposed at a position opposite to the plurality of light sources 64, and a space is formed between the lens portion 68 and the plurality of light sources 64. In the exposure device 40, the light emitted from the plurality of light sources 64 is irradiated to the photosensitive drum 32 (see Figure 1 ) surface.

[0116] The light emitting unit 44 has a driving substrate 72 mounted on the support body 60 via a mounting member 70. In other words, a gap is formed between the support body 60 and the driving substrate 72 by the mounting member 70. The driving substrate 72 is a substrate for driving the light emitting unit 44, and an ASIC (application specific integrated circuit) substrate is used, for example.

[0117] The support body 60 is composed of a rectangular parallelepiped component. In the present embodiment, the support body 60 is composed of a metal block like the base body 42. For example, the support body 60 is composed of steel or stainless steel. Here, the base body 42 may also be composed of a metal block other than steel or stainless steel. For example, it may be a metal block of aluminum having a higher thermal conductivity than steel or stainless steel and being lighter. However, if the thermal expansion coefficients of the base body 42 and the support body 60 are different, deformation and deflection may occur. Therefore, from the viewpoint of suppressing deformation and deflection, it is preferred that the base body 42 and the support body 60 are composed of the same material.

[0118] The surface of the support body 60 on the side close to the base body 42 is formed with a screw hole 74 to which the shaft portion 58B of the fastening member 58 is fastened. The screw hole 74 is provided at a position facing the through hole 84 of the base body 42.

[0119] The fastening member 58 is inserted into the concave 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 60 via the spacer 56 while the shaft portion 58B of the fastening member 58 passes through the through hole 84 of the base 42. Thus, the light emitting unit 44 is fixed to the base 42 from the inside of the concave portion 82 of the base 42 by the fastening member 58. In the state where the light emitting unit 44 is fixed to the base 42 by the fastening member 58, the spacer 56 is interposed between the base 42 and the support 60.

[0120] Here, a method of fixing the support body 60 from the front side (the exit surface side) relative to the front side of the base 42 using a fastening member 58 is considered. However, the support body 60 of the present embodiment is different from the support body made of a resin material and the support body made of sheet metal, and is made of a heavy metal block. Therefore, the size of the fastening member 58 also needs to be a size commensurate with the mass. In this case, a space for a fastening member 58 of a larger size is required on the front side of the support body 60, and the size of the support body 60 will increase. Therefore, in the present embodiment, it is configured to be fastened from the back side of the support body 60.

[0121] In the structure in which the fastening member 58 is provided not only on the both ends but also on the central part of the support body 60, it is difficult to adopt a structure in which fastening is performed from the front side of the support body 60 because the light source 64 is present on the central part. Therefore, by adopting a structure in which fastening is performed from the back side of the base 42, in the structure in which fastening is performed on both ends and the central part of the support body 60, fastening is performed only from the back side of the base 42.

[0122] When viewed from the optical axis direction of the light source 64, the screw hole 74 and the concave portion 82 of the base 42 are arranged at a position overlapping with the light source 64. With this structure, the heat generated by the light source 64 is easily released to the base 42 side via the fastening member 58 compared to the case where the screw hole 74 and the concave portion 82 of the base 42 are arranged at a position not overlapping with the light source 64.

[0123] (Spacer 56)

[0124] like Figures 5 to 8 As shown in FIG. 1 , the spacer 56 is sandwiched between the base 42 and the light emitting portion 44 in the direction of the optical axis of the light source 64. As an example, the spacer 56 is plate-shaped and is composed of one component (i.e., a single component). The spacer 56 is arranged on the inclined surface 80A (refer to FIG. 1 ) of the recessed portion 80 of the base 42. Fig.10 ). At the position where the spacer 56 is arranged on the inclined surface 80A, the thickness of the spacer 56 is greater than or equal to the depth of the recessed portion 80 (see Figure 7 The fastening member 58 fixes the light emitting portion 44 to the base 42 in such a manner that a compressive load is applied to the spacer 56 .

[0125] The spacer 56 is made of a material having a higher thermal conductivity than polyacetal resin (POM). As a material having a higher thermal conductivity than polyacetal resin, for example, metal or ceramic can be cited. The thermal conductivity of polyacetal resin is 0.25 W / m·K. The thermal conductivity of silicon carbide (SiC) as an example of ceramic is 60 W / m·K, and the thermal conductivity of carbon steel as an example of metal is 41 W / m·K. Here, the thermal conductivity is a value measured according to JIS R1611-1997. In the present embodiment, the spacer 56 is made of steel or stainless steel. Thus, the spacer 56 forms a heat dissipation path for dissipating heat from the support body 60 of the light emitting portion 44 to the base 42. In the exposure device 40, the heat from the light emitting element substrate 62 and the drive substrate 72 of the light emitting portion 44 is dissipated from the support body 60 to the base 42 via the spacer 56. Therefore, the spacer 56 becomes a part of the heat dissipation path when the heat is dissipated from the support body 60 to the base 42 via the spacer 56.

[0126] As an example, the spacer 56 is U-shaped when viewed from the optical axis direction of the light source 64. In the present embodiment, the spacer 56 includes a rectangular plate-shaped portion 56A and a recessed portion 56B cut from one side of the plate-shaped portion 56A. When the spacer 56 is disposed on the inclined surface 80A of the recessed portion 80 of the base 42, the recessed portion 56B surrounds a portion of the periphery of the through hole 84 (for example, a semicircular portion of the through hole 84) (see Fig.10 As an example, the spacer 56 is arranged in a direction from the opening side of the recessed portion 56B toward the downward slope of the inclined surface 80A, that is, the spacer 56 is arranged in a direction from the opening side of the recessed portion 56B toward the inner side of the short side direction (arrow X direction) of the base 42.

[0127] The inner diameter of the recessed portion 56B of the spacer 56 is larger than the outer diameter of the shaft portion 58B of the fastening member 58. Thus, the shaft portion 58B of the fastening member 58 passes through the recessed portion 56B ( Fig.11 In the threaded hole 74 (refer to Figure 7 ) When the fastening member 58 is loosened, the spacer 56 can be inserted and removed between the base 42 and the support body 60. In this embodiment, the recessed portion 56B of the spacer 56 opens toward the inner side in the short side direction (arrow X direction) of the base 42 (refer to Figure 6 ), so the spacer 56 can be inserted and removed from the outside of the short side direction (arrow X direction) of the base 42.

[0128] For example, in the initial assembly, the spacer 56 is arranged from the upper side of the recessed portion 80 of the base 42. When the spacer 56 is replaced when adjusting the imaging position of the light of the light emitting unit 44, the spacer 56 is replaced in the screw hole 74 (see Figure 7) With the fastening member 58 loosened, the spacer 56 is inserted and pulled out from between the base 42 and the support body 60 in the inclination direction of the inclined surface 80A.

[0129] As described above, three spacers 56 are arranged at intervals in one direction (arrow Z direction) of the base 42 for one light emitting portion 44. In the present embodiment, the spacers 56 are arranged at both ends of the support 60 in one direction, and at the center of the support 60 in one direction (see FIG. Figure 5 ). Here, the central portion of the support body 60 in one direction refers to the central portion of 1 / 3 of the support body 60 in the length direction. The two end portions of the support body 60 in one direction refer to the two side portions of 1 / 3 of the length direction of the support body 60. The thickness of the three spacers 56 configured for one light-emitting portion 44 can also be adjusted according to their positions in one direction (arrow Z direction) of the substrate 42. By adjusting the thickness of the three spacers 56, the imaging position of the light of the light-emitting portion 44 can be adjusted according to the position of the spacers 56 in one direction (arrow Z direction) of the substrate 42.

[0130] For example, in a structure where one spacer 56 is arranged in one direction (arrow Z direction) of the substrate 42 for one light-emitting section 44, the imaging position of the light from the light-emitting section 44 is adjusted in the one-dimensional up-down direction (arrow Y direction). For example, in a structure where two spacers 56 are arranged at intervals in one direction (arrow Z direction) of the substrate 42 for one light-emitting section 44, the imaging position of the light from the light-emitting section 44 is adjusted using a straight line on a two-dimensional YZ plane. In other words, the inclination of the support body 60 is adjusted using the difference in thickness between the two spacers 56, thereby adjusting the imaging position of the light. As in the exposure device 40 of the present embodiment, in a structure where three spacers 56 are arranged in one direction (arrow Z direction) of the substrate 42 for one light-emitting section 44, the imaging position of the light from the light-emitting section 44 is adjusted using a curve on a two-dimensional YZ plane. In other words, the shape of the support body 60 is adjusted to a curved shape using the difference in thickness between the three spacers 56, thereby adjusting the imaging position of the light.

[0131] Here, assuming that the support body 60 is made of a resin material, it has lower rigidity than metal, so it is easy to adjust the shape of the support body 60 into a curved shape. On the other hand, in the case where the support body 60 is a metal block as in the present embodiment, the rigidity is very high compared to the resin material, so the support body 60 is difficult to bend and difficult to adjust the shape into a curved shape. However, in a full-color printer for commercial printing, a slight difference in imaging position may cause problems in image quality. Therefore, even if it is a metal block that is difficult to adjust the shape into a curved shape, it is preferred to adjust it using the difference in thickness of the three spacers 56. The number of spacers 56 may also be 4 or more.

[0132] When viewed from the optical axis direction of the light source 64, the spacer 56 is disposed at a position overlapping the light source 64. With this structure, the heat generated by the light source 64 is easily released to the base 42 side via the spacer 56, compared with the case where the spacer 56 is disposed at a position not overlapping the light source 64. Although all the spacers 56 do not need to be disposed at a position overlapping the light source 64, if all the spacers 56 are disposed at an overlapping position, the heat dissipation effect is higher than the structure in which only one spacer 56 is disposed at an overlapping position.

[0133] <Function and Effect>

[0134] Next, the operation and effects of this embodiment will be described.

[0135] The exposure device 40 includes a base 42 extending in one direction (arrow Z direction) and a light emitting unit 44, wherein a plurality of light sources 64 (see FIG. 1 ) arranged in one direction are provided. Figure 7 ) is supported by a support body 60, which is extended in one direction and is composed of a metal block. The exposure device 40 is provided with a spacer 56, which is sandwiched between the base 42 and the light emitting portion 44 in the direction of the optical axis of the light source 64 (refer to Figure 7 ). In the exposure device 40 , the light emitting section 44 is fixed to the base 42 by the fastening member 58 in such a manner that a compressive load is applied to the spacer 56 .

[0136] In the above-mentioned exposure device 40, the base 42 is arranged over the entire length of the axial direction of the photosensitive drum 32. Three light emitting units 44 are arranged staggered in one direction of the base 42, and any one or more of the three light emitting units 44 are opposite to the region where the photosensitive body is provided in the axial direction of the photosensitive drum 32. In the exposure device 40, light from the light emitting unit 44 is irradiated to the photosensitive drum 32, thereby forming an electrostatic latent image in the region where the photosensitive body is provided on the photosensitive drum 32.

[0137] Here, use Fig.13A light emitting device 200 according to a first comparative example will be described.

[0138] like Fig.13 As shown, in the light emitting device 200, the light emitting unit 204 is fixed to the base 202 in a state where the light emitting unit 204 is in direct contact with the base 202. The light emitting unit 204 may be fixed to the base 202 by bonding or by using a fastening member (not shown).

[0139] In the light emitting device 200, the light emitting unit 204 is in direct contact with the base 202, so even if the driving substrate (not shown) or the like generates heat when the light emitting unit 204 is driven, heat dissipation from the light emitting unit 204 to the base 202 is good. However, in the light emitting device 200, since the light emitting unit 204 is in direct contact with the base 202, there is a case where the focus of the light emitting unit 204 is deviated at different positions in the long side direction (arrow Z direction) of the base 202 due to the surface accuracy of the bottom surface of the light emitting unit 204 or the front surface of the base 202. Here, the focus deviation refers to the deviation of the focus of the light emitting unit in the long side direction of the light emitting device, and refers to the focus deviation caused by the deviation of mechanical parts such as the base or the deviation of functional parts such as the lens part, and the focus deviation caused by deformation due to self-weight or heat over time.

[0140] In contrast, in the exposure device 40 of the present embodiment, a spacer 56 is provided between the base 42 and the light emitting portion 44 in the direction of the optical axis of the light source 64, and the light emitting portion 44 is fixed to the base 42 by a fastening component 58 in such a manner that a compressive load is applied to the spacer 56.

[0141] Thus, in the exposure device 40, the position of the light emitting unit 44 (i.e., the plurality of light sources 64) in one direction (Z direction) of the base 42 can be adjusted by the spacer 56, and the imaging position based on the plurality of light sources 64 can be adjusted. Therefore, in the exposure device 40, compared with the case where the light emitting unit is fixed to the base in a manner that the light emitting unit is in direct contact with the base, the focus deviation caused by the position of the light emitting unit 44 in one direction is suppressed.

[0142] In the exposure device 40, three spacers 56 are arranged at intervals in one direction (Z direction) of the light emitting section 44. In the exposure device 40, the inclination of the light emitting section 44 with respect to the base 42 can be adjusted compared to the case where the spacer is arranged at one position of the light emitting section.

[0143] In the exposure device 40 , the adjustment accuracy of the inclination of the light emitting section 44 is improved compared to the case where the spacer is arranged on the central portion side of the support body.

[0144] In the exposure device 40 , compared with a case where two spacers are arranged at intervals in one direction of the light emitting portion, the light emitting portion 44 can be adjusted into a curved shape, that is, three-dimensional adjustment is possible.

[0145] In the exposure device 40, the plurality of light emitting units 44 are fixed to the base 42 by the fastening member 58 with the spacer 56 interposed therebetween. Therefore, in the exposure device 40, in the structure in which the plurality of light emitting units are provided on the base, focus deviation between the plurality of light emitting units 44 is suppressed.

[0146] In the exposure device 40, the plurality of light emitters 44 are arranged staggered in one direction of the substrate 42. Therefore, in the exposure device 40, light can be irradiated over a longer range in one direction of the substrate 42 than when the plurality of light emitters are arranged in parallel on the substrate.

[0147] Here, use Fig.14 A light emitting device 210 according to a second comparative example will be described.

[0148] like Fig.14 As shown, in the light emitting device 210, the light emitting portion 214 is fixed to the upper side of the base 212 in the vertical direction by a fastening bolt 216, and a coil spring 218 is sandwiched between the base 212 and the light emitting portion 214, and the coil spring 218 is arranged around the shaft 216B of the fastening bolt 216. The base 212 is composed of a block component 212A, and a through hole 212B is formed in the block component 212A along the vertical direction (arrow Y direction) for the shaft 216B of the fastening bolt 216 to pass through. A threaded hole 214B is formed on the bottom surface 214A of the light emitting portion 214 for fastening the shaft 216B of the fastening bolt 216.

[0149] In the light emitting device 210, the shaft portion 216B of the fastening bolt 216 is inserted into the through hole 212B from the lower side in the vertical direction of the base 212. A coil spring 218 having an axial length longer than the protruding length of the shaft portion 216B is arranged around the shaft portion 216B protruding upward in the vertical direction of the base 212. Then, the shaft portion 216B of the fastening bolt 216 is fastened to the threaded hole 214B of the light emitting portion 214 so that the head portion 216B contacts the lower surface of the base 212. At this time, the coil spring 218 is in a compressed state. The structure of the light emitting device 210 is included in the scope of the present invention.

[0150] In the above-mentioned light emitting device 210, by adjusting the compression force of the coil spring 218, the imaging position of the light of the light emitting portion 214 in the long side direction (Z direction) of the base 212 can be adjusted. However, in the light emitting device 210, the heat dissipation path from the light emitting portion 214 to the base 212 is only the fastening bolt 216 and the coil spring 218, so the heat dissipation effect from the light emitting portion 214 to the base 212 is reduced.

[0151] In contrast, in the exposure device 40 of the present embodiment, a plate-shaped spacer 56 is interposed between the base 42 and the light emitting section 44. The plate-shaped spacer 56 increases the contact area between the spacer 56 and the base 42, and the contact area between the spacer 56 and the light emitting section 44. Therefore, in the exposure device 40, heat dissipation from the light emitting section 44 to the base 42 becomes easier than in the case where the spacer is a coil spring.

[0152] The exposure device 40 is provided with the fastening member 58 penetrating the spacer 56. Therefore, in the exposure device 40, the mounting portion of the spacer 56 can be made compact compared to the case where the spacer is provided at a position different from the fastening member.

[0153] In the exposure device 40, the spacer 56 can be inserted and removed between the base 42 and the support 60 in a state where the fastening member 58 is loosened. Therefore, in the exposure device 40, the focus deviation adjustment operation is easier than when the light emitting unit is removed from the base when inserting and removing the spacer.

[0154] In the exposure device 40, the spacer 56 is U-shaped when viewed from the optical axis direction of the light source 64. Therefore, in the exposure device 40, the structure of the spacer 56 is simpler than when the spacer is a split type. Since the spacer 56 is composed of one component, it is easier to handle than when the spacer is a split type.

[0155] In the exposure device 40, the base 42 is provided with a recessed portion 80 into which the spacer 56 enters, and the inclined surface 80A constituting the bottom surface of the recessed portion 80 is a cut surface. Therefore, compared with the case where the spacer is arranged on the front surface of the outer side of the base in the exposure device 40, the adjustment accuracy of the focus deviation of the light emitting unit 44 is improved. In the exposure device 40, compared with the case where the recessed portion of the base 42 is formed by a mold or the like, it is easy to form the recessed portion 80 in the base 42.

[0156] In the exposure device 40, the base 42 is provided with a recess 80 into which the spacer 56 enters, and the recess 80 has no wall on at least one side in the short side direction of the base 42. Therefore, in the exposure device 40, the spacer 56 can be easily inserted and removed compared with the case where the recess has a wall around it.

[0157] In the exposure device 40, a recessed portion into which the spacer 56 enters is provided on the base 42, and the bottom surface of the recessed portion 80 is an inclined surface 80A inclined with respect to the front surface 42A of the base 42. The inclination angle of the inclined surface 80A is an angle at which the optical axis is directed toward the rotation center of the photosensitive drum 32 when the exposure device 40 is positioned relative to the photosensitive drum 32. Therefore, compared with the case where the bottom surface of the recessed portion is parallel to the front surface of the base, the light from the light emitting portion 44 is irradiated perpendicularly to the surface of the photosensitive drum 32. As a result, for example, the irradiation shape of the light on the surface of the photosensitive drum 32 is less likely to be deformed. Even when the base 42 is offset in the short-side direction of the base 42, the variation of the distance to the surface of the photosensitive drum 32 is suppressed. In addition, when the light source 64 is composed of light emitting element arrays arranged in a staggered manner, the distance from each of the light emitting element arrays arranged staggered in the short-side direction of the light emitting portion 44 to the surface of the photosensitive drum 32 is less likely to differ.

[0158] In the exposure device 40, the plurality of light emitting units 44 are arranged staggered in the short-side direction (X direction) of the substrate 42, and the inclined surface 80A corresponding to the light emitting unit 44 arranged on one side in the short-side direction and the inclined surface 80A corresponding to the light emitting unit 44 arranged on the other side in the short-side direction are inclined in opposite directions. Therefore, in the exposure device 40, even when the plurality of light emitting units are arranged staggered in the short-side direction of the substrate 42, light from the plurality of light emitting units 44 is irradiated perpendicularly to the surface of the photosensitive drum 32, compared with the case where the inclined surfaces of the plurality of light emitting units have the same inclination direction. Thus, for example, the irradiation shape of the light on the surface of the photosensitive drum 32 is less likely to be deformed. Even when the substrate 42 is offset in the short-side direction of the substrate 42, the variation of the distance to the surface of the photosensitive drum 32 is suppressed. Furthermore, when the light source 64 is composed of light emitting element arrays arranged in a staggered manner, the distance from each of the light emitting element arrays arranged staggered in the short-side direction of the light emitting unit 44 to the surface of the photosensitive drum 32 is less likely to be different.

[0159] In the exposure device 40, the spacer 56 having a thickness greater than or equal to the depth of the recessed portion 80 is disposed on the inclined surface 80A of the base 42. Therefore, in the exposure device 40, the interference between the front surface 42A of the base 42 and the light emitting portion 44 is suppressed compared to the case where a spacer having a thickness less than the depth of the recessed portion is disposed.

[0160] In the exposure device 40, the base 42 is made of a metal block, and the spacer 56 is made of a material having a higher thermal conductivity than resin. Therefore, in the exposure device 40, heat dissipation from the light emitting section 44 to the spacer 56 and the base 42 is improved compared to the case where the base or the spacer is made of resin.

[0161] In the exposure device 40, the spacer 56 forms a heat dissipation path from the support body 60 to the base 42. Therefore, in the exposure device 40, compared with the case where the spacer is composed of a heat insulating portion, heat dissipation from the light emitting portion 44 to the spacer 56 and the base 42 becomes better.

[0162] In the exposure device 40, the back surface 42B of the base 42 opposite to the spacer 56 has a concave portion 82 cut toward the spacer 56 side, and the light emitting unit 44 is fixed to the base 42 from the inside of the concave portion 82 by the fastening member 58. Therefore, in the exposure device 40, compared with the case where the light emitting unit is fixed to the plate-like portion of the base by the fastening member, it is possible to fix the base 42 by the fastening member 58 having a shorter length without reducing the thickness of the entire base 42.

[0163] In the image forming apparatus 10 having the exposure device 40, the exposure device 40 and the photosensitive drum 32 are provided, the photosensitive drum 32 moves relative to the exposure device 40 in a direction intersecting one direction (Z direction), and the light from the exposure device 40 is irradiated to the photosensitive drum 32. An area where a photosensitive material is arranged is provided on the surface of the photosensitive drum 32. Therefore, in the image forming apparatus 10, compared with the case where the light emitting portion is fixed to the substrate in a manner that the light emitting portion is in direct contact with the substrate, the image quality reduction when the image light is irradiated to the photosensitive drum 32 is suppressed.

[0164] In the image forming apparatus 10 having the exposure device 40, the area where the photosensitive material is arranged is provided on the surface of the photosensitive drum 32, which is a cylindrical member and rotates in the circumferential direction. Therefore, in the image forming apparatus 10, in the structure in which light is irradiated to the area on the surface of the cylindrical member, the image quality is suppressed from being degraded when the image light is irradiated.

[0165] [Second embodiment]

[0166] Fig.12 A drawing device 150 including a light emitting device 152 according to a second embodiment is shown. The same components as those in the first embodiment are denoted by the same reference numerals and their description is omitted.

[0167] like Fig.12 As shown, the drawing device 150 includes a light emitting device 152 and a cylindrical member 154 which is arranged along the longitudinal direction of the light emitting device 152 and rotates in the circumferential direction.

[0168] The light emitting device 152 has the same structure as the exposure device 40 of the first embodiment. More specifically, the light emitting device 152 includes a base 42 extending in one direction (arrow Z direction), three light emitting units 44, and a spacer 56 sandwiched between the base 42 and the light emitting units 44. As with the exposure device 40 of the first embodiment, the light emitting device 152 is provided with a fastening member (not shown) for fixing the light emitting unit 44 to the base 42 in such a manner that a compressive load is applied to the spacer 56.

[0169] The cylindrical member 154 has a cylindrical portion 154A and shaft portions 154B extending on both sides of the cylindrical portion 154A. The shaft portion 154B is rotatably supported by a frame (not shown), and the cylindrical portion 154A rotates in the circumferential direction by the rotation of the shaft portion 154B.

[0170] A substrate 156 is mounted on the surface of the cylindrical portion 154A. An area 156A where a photosensitive material is arranged is provided on the surface of the substrate 156. As an example, the substrate 156 is a plate for computer-to-plate (CTP) used in a platemaking process of offset printing. As an example, the area 156A where a photosensitive material is arranged is an area where a photosensitive material such as a photoresist is applied.

[0171] In the drawing device 150, while rotating the cylindrical member 154, the light emitting device 152 irradiates a predetermined pattern of light to the region 156A of the substrate 156 where the photosensitive material is arranged. As a result, a predetermined pattern is drawn in the region 156A of the substrate 156 where the photosensitive material is arranged. Then, by developing the substrate 156, a printing plate used in an offset printing device is produced. As an example, a laser element can be used as a light source of the drawing device 150 in this case.

[0172] The above-described light emitting device 152 has the following functions and effects in addition to the functions and effects of the same configuration as the exposure device 40 of the first embodiment.

[0173] In the above-mentioned light emitting device 152, similarly to the exposure device 40 of the first embodiment, a base 42, three light emitting units 44, a spacer 56 sandwiched between the base 42 and the light emitting units 44, and a fastening member (not shown) for fixing the light emitting units 44 to the base 42 are provided. Therefore, in the drawing device 150 having the light emitting device 152, the image quality degradation during drawing is suppressed compared with the case where the light emitting unit is fixed to the base in a manner that the light emitting unit is in direct contact with the base.

[0174] In the drawing device 150 having the light emitting device 152 described above, in the configuration in which light is irradiated to the region 156A of the substrate 156 on the surface of the cylindrical member 154 where the photosensitive material is arranged, degradation of image quality during drawing is suppressed.

[0175] [Supplementary explanation]

[0176] In the exposure device 40 of the first embodiment and the light emitting device 152 of the second embodiment, three light emitting units 44 are arranged on the base 42, but the present invention is not limited to this structure. For example, a structure in which one light emitting unit is arranged on the base, a structure in which two light emitting units are arranged on the base, or a structure in which four or more light emitting units are arranged on the base may also be adopted. The positions of the plurality of light emitting units arranged on the base can also be appropriately set.

[0177] In the exposure device 40 of the first embodiment and the light emitting device 152 of the second embodiment, the shape of the base 42 can be changed. The components of the light emitting section 44 or the shapes of the components of the light emitting section 44 can be changed.

[0178] In the exposure device 40 of the first embodiment and the light emitting device 152 of the second embodiment, the number, shape, etc. of the spacers 56 can be changed. For example, it can be a structure in which one spacer is arranged for one light emitting portion, or it can be a structure in which at least two spacers are arranged at intervals in one direction of the substrate. For example, in the case where two spacers are arranged for one light emitting portion, it is preferred to arrange the spacers at both ends in one direction of the support body of the light emitting portion. The spacer is not limited to a plate shape, and can be, for example, a block shape. The spacer may not be a single component, and may be divided into two or more.

[0179] In the exposure device 40 of the first embodiment and the light emitting device 152 of the second embodiment, the recess 80 of the substrate 42 may be not provided, and a spacer may be arranged on the front surface of the substrate. The spacer may be arranged on the flat bottom surface of the recess without providing an inclined surface. In the case where an inclined surface is provided in the recess, the inclined surfaces on both sides may be inclined in the same direction instead of being inclined in opposite directions in the short side direction of the substrate. In the case where an inclined surface is provided in the recess, a wall may be provided around the inclined surface. The fixing portion such as a fastening member and the spacer may be provided at separate positions.

[0180] In the drawing device 150 of the second embodiment, the substrate 156 attached to the cylindrical portion 154A of the cylindrical member 154 is irradiated with light from the light emitting device 152, but the present invention is not limited to this structure. For example, the substrate may be arranged on a flat table, the light emitting device 152 and the table may be relatively moved in a direction intersecting one direction of the light emitting device 152, and the light emitting device 152 may be irradiated with light to the substrate.

[0181] In the drawing device 150 of the second embodiment, the substrate 156 is a CTP plate used in the platemaking process of offset printing, and light is irradiated from the light emitting device 152 to the area 156A of the substrate 156 where the photosensitive material is arranged, but the present invention is not limited to this structure. For example, the above-mentioned light emitting device and drawing device can be used for exposure when manufacturing a printed wiring board (PWB: printed wiring board). For example, a substrate coated with a photosensitive material such as a photoresist can also be directly drawn without using a photomask, thereby manufacturing a printed wiring board. The substrate to be used can be a rigid substrate or a flexible substrate. In the case of a flexible substrate, it can be fixed to Fig.12 The cylindrical member 154 is rotated while being drawn.

[0182] Furthermore, the above-mentioned light emitting device and drawing device can be used for the following parts to which photolithography is applied: formation of color filters in the manufacturing process of liquid crystal display devices (LCD), exposure of dry film resist (DFR) in the manufacturing process of thin film transistors (TFT), exposure of dry film resist (DFR) in the manufacturing process of plasma display panels (PDP), exposure of photosensitive materials such as photoresists in the manufacturing process of semiconductor elements, exposure of photosensitive materials such as photoresists in the platemaking process of printing other than offset printing such as gravure printing, or exposure of photosensitive materials in the manufacturing process of watch parts. Here, photolithography refers to the following technology: by exposing the surface of a substance provided with a photosensitive material in a pattern, a pattern consisting of exposed parts and unexposed parts is generated.

[0183] The above-mentioned light emitting device and drawing device can also use any of photon mode photosensitive materials that directly record information by exposure and thermal mode photosensitive materials that record information using heat generated by exposure. As the light source of the drawing device 150, LED elements and laser elements can be used according to the exposure object.

[0184] Although specific embodiments of the present invention have been described in detail, the present invention is not limited to these embodiments, and it is obvious to those skilled in the art that various other embodiments can be implemented within the scope of the present invention.

[0185] This application claims priority based on Japanese patent application No. 2020-054927 filed on March 25, 2020.

Claims

1. A light emitting device, comprising: a base extending in one direction; a light emitting section in which a plurality of light sources arranged along the one direction are supported by a support body, the support body being composed of a metal block extending in the one direction; A spacer sandwiched between the base and the light emitting portion in the optical axis direction of the light source; and a fixing portion that fixes the light emitting portion to the base in such a manner that a compressive load is applied to the spacer, The base body is provided with a recessed portion for the spacer to enter, and the bottom surface of the recessed portion is an inclined surface inclined relative to the front surface of the base body. The plurality of light emitting portions are staggeredly arranged in the short side direction of the substrate, and the inclined surface corresponding to the light emitting portion arranged on one side in the short side direction and the inclined surface corresponding to the light emitting portion arranged on the other side in the short side direction are inclined in opposite directions.

2. The light emitting device according to claim 1, wherein: At least two of the spacers are arranged at intervals in the one direction.

3. The light emitting device according to claim 2, wherein: The spacer is disposed at least at both ends of the support body in the one direction.

4. The light emitting device according to claim 2 or 3, wherein: At least three of the spacers are arranged at intervals in the one direction.

5. The light emitting device according to claim 2 or 3, wherein: The plurality of light emitting parts are fixed to the base body by the fixing part in a state where the spacer is sandwiched between the plurality of light emitting parts and the base body.

6. The light emitting device according to claim 5, wherein: The plurality of light emitting units are arranged to be staggered in the one direction.

7. The light emitting device according to any one of claims 1 to 3, wherein: The fixing portion has a fastening member that passes through the spacer.

8. The light emitting device according to claim 7, wherein: The spacer can be inserted and removed between the base body and the support body in a state where the fastening member is loosened.

9. The light emitting device according to claim 8, wherein: The spacer is in a plate shape.

10. The light emitting device according to claim 9, wherein: The spacer has a U-shape when viewed from the optical axis direction.

11. The light emitting device according to any one of claims 1 to 3, wherein: The base body is provided with a recessed portion for the spacer to enter, and the bottom surface of the recessed portion is a cutting surface.

12. The light emitting device according to claim 8, wherein: The base body is provided with a recessed portion into which the spacer enters, and the recessed portion has no wall on at least one side in a short side direction of the base body.

13. The light emitting device according to claim 1, wherein: The spacer having a thickness equal to or greater than the depth of the recessed portion is disposed on the inclined surface.

14. The light emitting device according to any one of claims 1 to 3, wherein: The base is made of a metal block, and the spacer is made of a material having a higher thermal conductivity than polyacetal resin.

15. The light emitting device according to claim 14, wherein: The spacer forms a heat dissipation path for dissipating heat from the support body to the base body.

16. The light emitting device according to any one of claims 1 to 3, wherein: The surface of the base body opposite to the spacer has a concave portion cut out toward the spacer side. The light emitting portion is fixed to the base from inside the concave portion by a fastening member constituting the fixing portion.

17. A drawing device, comprising: The light emitting device according to any one of claims 1 to 16; and A region where a photosensitive material is disposed moves relative to the light emitting device in a direction intersecting the one direction and is irradiated with light from the light emitting device.

18. The drawing device according to claim 17, wherein: The region is provided on the surface of a cylindrical member that rotates in the circumferential direction.

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