JP2019209586A - Exposure device and image formation device - Google Patents

Abstract

To reduce variation in relative position among multiple light sources.SOLUTION: An exposure device includes multiple light source substrates 201, 202, 203 including multiple light sources 220 each arranged along a main scanning direction. The light source substrates 201, 202, 203 are disposed so that optical axes of the light sources 220 included in respective light source substrates 201, 202, 203 are deviated in a sub-scanning direction crossing with the main scanning direction.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an exposure apparatus and an image forming apparatus, and more particularly to an exposure apparatus in which a plurality of light sources are arranged along a main scanning direction and an image forming apparatus including the exposure apparatus.

  In recent years, a print head using an OLED (Organic Light-Emitting Diode) as a light source is known. In this print head, it is necessary to appropriately set the relative positions of the plurality of light sources and the photosensitive drum irradiated with light.

  For example, in Japanese Patent Laid-Open No. 2015-157446, a plurality of light emitting units are arranged in order to appropriately correct the straightness of an imaging optical element in which an incident surface and an output surface are inclined. The imaging optical element, comprising: a provided substrate; an imaging optical element that uses light from each of the light emitting portions as a light spot on an image plane; and a correction member that corrects deflection in the imaging optical element. Has an incident surface on which light from each of the light emitting units is incident and an output surface that emits light incident from the incident surface, and the incident surface and the output surface are inclined. The imaging optical element is pressed against the correction member in the incident orthogonal direction orthogonal to the incident surface, and is pressed against the correction member in the emission orthogonal direction orthogonal to the emission surface. The print head is listed as .

Since the print head has a plurality of light sources arranged on the glass substrate along the main scanning direction, the print head often has a long shape in the main scanning direction. And since the some light source generate | occur | produces heat | fever, when the temperature of a glass substrate rises partially, there exists a problem that a glass substrate deform | transforms.
JP-A-2015-157446

  The present invention has been made to solve the above-mentioned problems, and one of the objects of the present invention is to provide an exposure apparatus in which the change in the relative positions of a plurality of light sources is reduced.

  Another object of the present invention is to provide an image forming apparatus capable of forming an image with stable image quality.

  The present invention has been made to solve the above-described problems. According to one aspect of the present invention, an exposure apparatus includes a plurality of light source substrates each including a plurality of light sources arranged along the main scanning direction. The plurality of light source substrates are arranged so that the optical axes of the plurality of light sources included in each of the plurality of light source substrates are shifted in the sub-scanning direction intersecting with the main scanning direction.

  According to this aspect, since each of the plurality of light source substrates includes a plurality of light sources, heat generated from the plurality of light sources can be distributed among the plurality of light source substrates. In addition, since the plurality of light source substrates are arranged so that the optical axes of the plurality of light sources are shifted in the sub-scanning direction, it is possible to secure a certain distance as the interval in the main scanning direction of the plurality of light sources on each of the plurality of light source substrates. it can. For this reason, since a heat source is disperse | distributed to a some light source board | substrate, a deformation | transformation of each of a some light source board | substrate can be made small. As a result, it is possible to provide an exposure apparatus in which changes in the relative positions of a plurality of light sources are reduced.

  Preferably, the plurality of light source substrates are arranged so as to be shifted in an overlapping direction intersecting with each of the main scanning direction and the sub-scanning direction.

  According to this aspect, since a plurality of light source substrates can be stacked in the overlapping direction, the size in the sub-scanning direction can be reduced.

  Preferably, each of the plurality of light source substrates is coupled to another light source substrate adjacent in the overlapping direction in a state where heat can be conducted in the contact region.

  According to this aspect, since heat is transferred between the plurality of light source substrates, heat generated from the plurality of light sources can be efficiently transferred.

  Preferably, a contact member that couples each of the plurality of light source substrates with another light source substrate in a contact region is further provided.

  According to this aspect, since the plurality of light source substrates are coupled by the contact member, heat can be transferred efficiently.

  Preferably, each of the plurality of light source substrates is physically coupled to another light source substrate adjacent in the overlapping direction in a coupling region.

  According to this aspect, each of the plurality of light source substrates is physically coupled to another light source substrate adjacent in the overlapping direction in the coupling region, and therefore, the plurality of light sources included in each of the two light source substrates in the sub-scanning direction. The distance can be determined based on the position where the two light source substrates are physically coupled.

  Preferably, each of the plurality of light source substrates is coupled with a first coupling region coupled with an adjacent light source substrate with an overlapping direction in the first direction, and with an adjacent light source substrate with a second direction opposite to the first direction in the overlapping direction. And each of the plurality of light source substrates includes the second coupling region, and the second coupling region is disposed between the first coupling region and the plurality of light sources in the sub-scanning direction.

  According to this aspect, in the light source substrate, the second coupling region is arranged between the first coupling region and the plurality of light sources in the sub-scanning direction. The distances in the scanning direction can be made equal.

  Preferably, in each of the plurality of light source substrates, the distance between the plurality of light sources on the light source substrate and the plurality of light sources on the light source substrate adjacent to each other in the first direction is the first direction. The positions of the first coupling region and the second coupling region are set so that the distances between the plurality of light sources adjacent to each other in the two directions are the same at a predetermined temperature.

  According to this aspect, the distance in the sub-scanning direction between the plurality of light sources included in each of the plurality of light source substrates can be made equal at a predetermined temperature.

  Preferably, each of the plurality of light source substrates further includes positioning means for determining a position in the sub-scanning direction at the same position in the sub-scanning direction as the plurality of light sources included in the light source substrate.

  According to this aspect, the relative position in the sub-scanning direction between the plurality of light sources included in each of the plurality of light source substrates can be set to a predetermined position.

  Preferably, the apparatus further includes a plurality of optical elements that respectively correspond to the plurality of light source substrates and collect the light emitted from the plurality of light sources on the subject.

  Preferably, the image forming apparatus includes the above exposure apparatus.

  According to this aspect, since the change in the relative position of the plurality of light sources is reduced by the exposure apparatus, the image quality is stabilized. As a result, an image forming apparatus capable of forming an image with stable image quality can be provided.

1 is a perspective view showing an external appearance of an MFP in one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing an internal configuration of the MFP. It is a perspective view which shows an example of an internal structure of exposure apparatus. It is a side view of a light source substrate. It is AA sectional view taken on the line of FIG. 3 of an exposure apparatus. It is a side view of the 1st-3rd light source board in the state where it was positioned. It is a top view of the 1st-3rd light source board | substrate in the positioned state.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  FIG. 1 is a perspective view showing an appearance of an MFP according to one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing the internal configuration of the MFP. Referring to FIGS. 1 and 2, MFP (Multi Function Peripheral) 100 includes a document reading unit 130 for reading a document, an automatic document conveyance device 120 for conveying a document to document reading unit 130, and a document reading An image forming unit 140 for forming a still image output by the unit 130 by reading a document on a sheet, a paper feeding unit 150 for supplying the image forming unit 140 with a sheet, a post-processing unit 155, a user interface As an operation panel 160.

  The automatic document feeder 120 handles one or more documents placed on the document tray 125 and conveys them one by one to the document reading unit 130. The document reading unit 130 exposes the image of the document set on the document glass 11 by the automatic document feeder 120 with the exposure lamp 13 attached to the slider 12 that moves below the document image. Reflected light from the document is guided to the lens 16 by the mirror 14 and the two reflecting mirrors 15 and 15A, and forms an image on a CCD (Charge Coupled Devices) sensor 18. The exposure lamp 13 and the mirror 14 are attached to a slider 12, and the slider 12 is moved by a scanner motor 17 in the arrow direction (sub-scanning direction) shown in FIG. Thereby, the document set on the document glass 11 can be scanned over the entire surface. As the exposure lamp 13 and the mirror 14 move, the two reflecting mirrors 15 and 15A move in the direction of the arrow in FIG. 2 at a speed V / 2. As a result, the optical path length from when the light applied to the document by the exposure lamp 13 is reflected by the document until it is imaged on the CCD sensor 18 is always constant. When the operation mode is switched from the power saving mode to the normal mode, the document reading unit 130 performs shading correction as an initialization process, and moves the slider 12 to a predetermined position.

  The reflected light imaged on the CCD sensor 18 is converted into image data as an electrical signal in the CCD sensor 18 and sent to the main circuit 110. The main circuit 110 performs A / D conversion processing, digital image processing, and the like on the received analog image data, and outputs the analog image data to the image forming unit 140. The main circuit 110 converts the image data into print data for cyan (C), magenta (M), yellow (Y), and black (K) and outputs the data to the image forming unit 140.

  The image forming unit 140 includes yellow, magenta, cyan, and black image forming units 20Y, 20M, 20C, and 20K. Here, “Y”, “M”, “C”, and “K” represent yellow, magenta, cyan, and black, respectively. An image is formed by driving at least one of the image forming units 20Y, 20M, 20C, and 20K. When all of the image forming units 20Y, 20M, 20C, and 20K are driven, a full color image is formed. Printing data for yellow, magenta, cyan, and black are input to the image forming units 20Y, 20M, 20C, and 20K, respectively. Since the image forming units 20Y, 20M, 20C, and 20K differ only in the color of the toner to be handled, the image forming unit 20Y for forming a yellow image will be described here.

  The image forming unit 20Y includes an exposure device 21Y to which yellow printing data is input, a photosensitive drum (image carrier) 23Y of the exposure device 21Y, a charging charger 22Y, a developing device 24Y, a transfer charger 25Y, Toner bottle 41Y. The toner bottle 41Y stores yellow toner. The toner bottle 41Y is held by a holding mechanism driven by a motor. The toner bottle 41Y has a spiral projection formed therein, and when rotated by the holding mechanism, the toner in the toner bottle 41Y is supplied to the developing device 24Y. The developing device 24Y includes a screw shaft for stirring the toner supplied from the toner bottle 41Y, a motor for rotating the screw shaft, and a gear for transmitting the power of the motor to the screw.

  The exposure device 21Y emits light according to the printing data (electrical signal) received from the main circuit 110, and exposes the photosensitive drum 23Y that is a subject. The photoconductive drum 23Y rotates when the power of the motor is transmitted through a gear. The photosensitive drum 23Y is charged by the charger 22Y and then irradiated with laser light emitted from the exposure device 21Y. Thereby, an electrostatic latent image is formed on the photosensitive drum 23Y. Subsequently, the developer 24Y places toner on the electrostatic latent image to form a toner image. The toner image formed on the photosensitive drum 23Y is transferred onto the intermediate transfer belt 30 by the transfer charger 25Y.

  On the other hand, the intermediate transfer belt 30 is suspended by the driving roller 33C and the roller 33A so as not to be loosened. When the drive roller 33C rotates counterclockwise in FIG. 2, the intermediate transfer belt 30 rotates counterclockwise in the drawing at a predetermined speed. As the intermediate transfer belt 30 rotates, the roller 33A rotates counterclockwise.

  As a result, the image forming units 20Y, 20M, 20C, and 20K sequentially transfer the toner images onto the intermediate transfer belt 30. The timing at which each of the image forming units 20Y, 20M, 20C, and 20K transfers the toner image onto the intermediate transfer belt 30 is adjusted by detecting a reference mark attached to the intermediate transfer belt 30. As a result, yellow, magenta, cyan, and black toner images are superimposed on the intermediate transfer belt 30.

  The toner image formed on the intermediate transfer belt 30 is transferred to a sheet by the transfer roller 26. The sheet on which the toner image has been transferred is conveyed to the fixing roller pair 32 and heated by the fixing roller pair 32. As a result, the toner is melted and fixed on the paper. Thereafter, the sheet is conveyed to the post-processing unit 155.

  In the paper feed cassettes 35, 35A, and 35B, sheets of different sizes are set. The paper stored in each of the paper feed cassettes 35, 35 A, and 35 B is supplied to the conveyance path by take-out rollers 36, 36 A, and 36 B attached to the paper feed cassettes 35, 35 A, and 35 B, respectively, and is fed by the paper feed roller 37. It is sent to the timing roller 31.

  The MFP 100 drives all of the image forming units 20Y, 20M, 20C, and 20K when forming a full-color image, but any one of the image forming units 20Y, 20M, 20C, and 20K when forming a monochrome image. Drive one. Further, an image can be formed by combining two or more of the image forming units 20Y, 20M, 20C, and 20K. Here, the tandem MFP 100 including the image forming units 20Y, 20M, 20C, and 20K that form the four color toners on the paper will be described, but the four color toners are sequentially supplied to the paper on one photosensitive drum. It may be a four-cycle MFP that transfers to the printer.

  The post-processing unit 155 includes a plurality of paper discharge trays. The post-processing unit 155 receives the paper on which the image is formed by the image forming unit 140, and executes post-processing on the paper. The post-processing is not limited, but a process of sorting a plurality of sheets by transporting a plurality of sheets to one of a plurality of discharge trays, a process of punching holes in the sheets, and driving staples into the sheets Includes processing.

  Next, the exposure apparatuses 21Y, 21M, 21C, and 21K will be described. Since exposure apparatuses 21Y, 21M, 21C, and 21K are all the same, here, exposure apparatus 21Y will be described as an example.

  FIG. 3 is a perspective view showing an example of the internal configuration of the exposure apparatus. Referring to FIG. 3, exposure apparatus 21Y includes three first light source substrates 201, second light source substrate 202 and third light source substrate 203, and three first light source substrates 201, second light source substrate 202 and third light source. Three rod lens arrays 221, 222, and 223 respectively corresponding to the substrate 203 are provided. Each of the three first light source substrates 201, the second light source substrate 202, and the third light source substrate 203 has a plurality of light sources 220 arranged along the main scanning direction. The light source 220 is an OLED (Organic Light-Emitting Diode). The light source 220 is not limited to an OLED, but may be an LED. The rod lens array 221 condenses the light emitted from the plurality of light sources 220 formed on the first light source substrate 201 on the photosensitive drum 23Y. For this reason, the relative positions of the first light source substrate 201 and the rod lens array 221 are determined by the positions of the plurality of light sources 220 formed on the first light source substrate 201. Similarly, the relative positions of the second light source substrate 202 and the corresponding rod lens array 222 are determined by the positions of the plurality of light sources 220 formed on the second light source substrate 202. The relative positions of the third light source substrate 203 and the corresponding rod lens array 223 are determined by the positions of the plurality of light sources 220 formed on the third light source substrate 203.

  The first light source substrate 201, the second light source substrate 202, and the third light source substrate 203 are arranged so that the distances in the sub-scanning direction of the optical axes of the plurality of light sources 220 included in each of them are a predetermined interval. Further, in each of the first light source substrate 201, the second light source substrate 202, and the third light source substrate 203, a plurality of light sources are arranged at equal intervals, and the first light source substrate 201, the second light source substrate 202, and the third light source substrate 203 are The optical axes of the plurality of light sources 220 included in each of the light sources 220 are shifted from each other without overlapping in the main scanning direction.

  FIG. 4 is a side view of the light source substrate. Here, a side view of the first light source substrate 201 is shown. The first light source substrate 201 includes a contact region 231 including a plurality of light sources 220 and a circuit region 233 in which an electric circuit for driving the plurality of light sources 220 is formed. In the circuit region 233, a plurality of electric circuits respectively corresponding to the plurality of light sources 220 are formed.

  5 is a cross-sectional view of the exposure apparatus taken along line AA in FIG. Here, three first light source substrates 201, a second light source substrate 202, a third light source substrate 203, and a part of the main body case 291 of the exposure apparatus 21Y are shown. Referring to FIG. 5, three first light source substrates 201, second light source substrate 202, and third light source substrate 203 are arranged so that main scanning directions in which a plurality of light sources 220 included therein are arranged are parallel to each other. Is done. Further, the three first light source substrates 201, the second light source substrate 202, and the third light source substrate 203 are arranged such that the optical axes of the plurality of light sources 220 included in each of them are shifted in the sub-scanning direction. Further, the three first light source substrates 201, the second light source substrate 202, and the third light source substrate 203 are arranged so that the plurality of light sources 220 included in each of them are shifted in the overlapping direction orthogonal to the main scanning direction and the sub scanning direction. The

  Specifically, the second light source substrate 202 is disposed above the first light source substrate 201, a portion of the first light source substrate 201 other than the region where the plurality of light sources 220 are formed, and a part of the second light source substrate 202. And overlap. The third light source substrate 203 is disposed below the first light source substrate 201, and a portion of the third light source substrate 203 other than the region where the plurality of light sources 220 are formed overlaps with a part of the second light source substrate 202. The region of the third light source substrate 203 where the plurality of light sources 220 are formed does not overlap with either the first light source substrate 201 or the second light source substrate 202.

  The second light source substrate 202 is in contact with the first light source substrate 201 via the contact member 241 in a contact region 231 including a plurality of light sources 220. The contact member 241 is not limited to a material, but is preferably a member having high thermal conductivity. The contact member 241 is attached to the second light source substrate 202 with an adhesive or the like. The contact member 241 is slidable with respect to the first light source substrate 201 without being bonded to the first light source substrate 201. Since the second light source substrate 202 is in contact with the first light source substrate 201 in the contact region 231 where the distance from the plurality of light sources 220 is the shortest, the heat generated by the plurality of light sources 220 of the second light source substrate 202 is contact members 241. And conducted to the first light source substrate 201. For this reason, in the 2nd light source board | substrate 202, the temperature rise in the some light source 220 can be made as small as possible, and the temperature which the 2nd light source board | substrate 202 raises partially can be made as low as possible.

  The first light source substrate 201 is in contact with the third light source substrate 203 via the contact member 241 in a contact region 231 including a plurality of light sources 220. The contact member 241 is attached to the first light source substrate 201 with an adhesive or the like. The contact member 241 is slidable with respect to the third light source substrate 203 without being bonded to the third light source substrate 203. Since the first light source substrate 201 is in contact with the third light source substrate 203 in the contact region 231 where the distance from the plurality of light sources 220 is the shortest, the heat generated by the plurality of light sources 220 of the first light source substrate 201 is contact members 241. And conducted to the third light source substrate 203. For this reason, in the 1st light source substrate 201, the temperature rise in the some light source 220 can be made as small as possible, and the temperature which the 1st light source substrate 201 raises partially can be made as low as possible.

  Thus, the first light source substrate 201 is in contact with the second light source substrate 202 through the contact member 241 and is in contact with the third light source substrate 203 through the contact member 241. In each of the light source substrate 202 and the third light source substrate 203, a partial temperature rise can be minimized. For this reason, in each of the 1st light source substrate 201, the 2nd light source substrate 202, and the 3rd light source substrate 203, the deformation | transformation by thermal expansion can be minimized. In particular, warpage in the main scanning direction, which is the longitudinal direction, can be reduced in each of the first light source substrate 201, the second light source substrate 202, and the third light source substrate 203.

  The first light source substrate 201 is coupled to the second coupling region 262 of the second light source substrate 202 via the first coupling member 281 in a first coupling region 251 different from the contact region 231. The material of the first coupling member 281 is not limited, but is preferably a member having high thermal conductivity. The first coupling member 281 is attached to the first light source substrate 201 and the second light source substrate 202 with an adhesive or the like. For this reason, the relative positions in the sub-scanning direction of the plurality of light sources 220 of the first light source substrate 201 and the plurality of light sources 220 of the second light source substrate 202 are determined based on the position of the first coupling member 281.

  The first light source substrate 201 is coupled to the first coupling region 253 of the third light source substrate 203 via the second coupling member 282 in a second coupling region 261 different from the contact region 231 including the plurality of light sources 220. . The second coupling member 282 is made of the same material as the first coupling member 281. The second coupling member 282 is attached to the first light source substrate 201 and the third light source substrate 203 with an adhesive or the like. For this reason, the relative positions in the sub-scanning direction of the plurality of light sources 220 of the first light source substrate 201 and the plurality of light sources of the third light source substrate 203 are determined based on the position of the second coupling member 282.

  The third light source substrate 203 is coupled to the main body case 291 via the third coupling member 283 in the contact region 231 including the plurality of light sources 220. The third coupling member 283 is not limited to a material, but is preferably a member having high thermal conductivity.

  In the first light source substrate 201, the first coupling region 251 and the second coupling region 261 are located upstream in the sub-scanning direction with respect to the plurality of light sources 220. In the first light source substrate 201, the second coupling region 261 is located between the first coupling region 251 and the plurality of light sources 220. In the second light source substrate 202, the second coupling region 262 is located upstream in the sub-scanning direction with respect to the plurality of light sources 220. In the third light source substrate 203, the first coupling region 253 is located upstream in the sub-scanning direction with respect to the plurality of light sources 220.

  Here, with reference to the second coupling member 282, the plurality of light sources 220 of the first light source substrate 201, the plurality of light sources 220 of the second light source substrate 202, and the plurality of light sources 220 of the third light source substrate 203 A change in the relative position will be described. Here, it is assumed that the first light source substrate 201, the second light source substrate 202, and the third light source substrate 203 have the same thermal expansion coefficient, and the temperatures of the first light source substrate 201, the second light source substrate 202, and the third light source substrate 203 are the same. Assuming that the temperature is uniform, a case where the temperature rises by ΔT will be described as an example.

  The distance between the second coupling region 262 and the plurality of light sources 220 in the second light source substrate 202 is L1, the distance between the second coupling region 261 and the plurality of light sources 220 in the first light source substrate 201 is L2, and the first. The distance between the first coupling region 251 and the second coupling region 261 in the light source substrate 201 is L3, and the distance between the first coupling region 253 and the plurality of light sources 220 in the third light source substrate 203 is L4.

  The plurality of light sources 220 on the third light source substrate 203 move to the downstream side in the sub-scanning direction by ΔL4. Further, the plurality of light sources 220 of the first light source substrate 201 move to the downstream side in the sub-scanning direction by ΔL2. Further, the second coupling region 262 of the second light source substrate 202 moves upstream in the sub-scanning direction by ΔL3, and the plurality of light sources 220 of the second light source substrate 202 perform sub-scanning by ΔL1 with respect to the second coupling region 262. Move downstream in the direction. For this reason, the plurality of light sources 220 of the first light source substrate 201 move to the upstream side in the sub-scanning direction by ΔL3−ΔL1 with respect to the second coupling member 282. The distance BT1 between the plurality of light sources 220 of the first light source substrate 201 and the plurality of light sources 220 of the second light source substrate 202, and the plurality of light sources 220 of the first light source substrate 201 and the plurality of light sources 220 of the third light source substrate 203. The interval BT2 is preferably the same before and after the temperature changes. Therefore, it is preferable to determine L1 to L4 so that the following expression (1) is satisfied.

(ΔL3−ΔL1) + ΔL2 = ΔL4−ΔL2 (1)
The distances L1 to L4 are preferably as small as possible. Further, when the values at which the temperatures of the first light source substrate 201, the second light source substrate 202, and the third light source substrate 203 converge are known in advance, using these values, the equation (1) is used. L1 to L4 may be determined.

<Modification>
In the embodiment described above, the first light source substrate 201 and the second light source substrate 202 are coupled by the first coupling member 281, and the first light source substrate 201 and the third light source substrate 203 are coupled by the second coupling member 282. I tried to do it. The exposure apparatus 21Y according to the modification is configured such that the first light source substrate 201 and the second light source substrate 202 are not coupled, and the first light source substrate 201 and the third light source substrate 203 are not coupled.

  FIG. 6 is a side view of the first to third light source substrates in a positioned state. FIG. 7 is a plan view of the first to third light source substrates in a positioned state. Referring to FIGS. 6 and 7, the first light source substrate 201 has protrusions 301 </ b> A and 301 </ b> B that are parallel to the main scanning direction at the same position in the sub scanning direction as the plurality of light sources 220. The second light source substrate 202 has protrusions 302A and 302B parallel to the main scanning direction at the same position in the sub-scanning direction as the plurality of light sources 220. The third light source substrate 203 has protrusions 303A and 303B parallel to the main scanning direction at the same position in the sub scanning direction as the plurality of light sources 220.

  The first positioning member 310A has a protrusion 301A, a protrusion 302A, and holes 311A, 312A, 313A into which the protrusion 303A is inserted, and is fixed to the main body case 291 of the exposure apparatus 21Y. The second positioning member 310B has holes 311B, 312B, and 313B into which the protrusion 301B, the protrusion 302B, and the protrusion 303B are inserted, and is fixed to the main body case 291 of the exposure apparatus 21Y.

  For this reason, even when the first light source substrate 201, the second light source substrate 202, and the third light source substrate 203 are thermally expanded due to a change in temperature, the plurality of light sources 220 of the first light source substrate 201, the second light source substrate. The relative positions in the sub-scanning direction of the main body case 291 and the plurality of light sources 220 of 202 and the plurality of light sources 220 of the third light source substrate 203 can be prevented from changing.

  As described above, MFP 100 according to the present embodiment functions as an image forming apparatus and includes exposure apparatuses 21Y, 21M, 21C, and 21K. Each of the exposure apparatuses 21Y, 21M, 21C, and 21K includes a first light source substrate 201, a second light source substrate 202, and a third light source substrate 203 in which a plurality of light sources 200 are arranged in the main scanning direction. Heat generated from 220 can be distributed among the first light source substrate 201, the second light source substrate 202, and the third light source substrate 203. In addition, since the first light source substrate 201, the second light source substrate 202, and the third light source substrate 203 are arranged so that the optical axes of the plurality of light sources 220 are shifted in the sub-scanning direction, the first light source substrate 201, the second light source substrate A certain distance can be secured as the interval in the main scanning direction of the plurality of light sources 220 in each of the 202 and the third light source substrate 203. For this reason, since the heat source is dispersed in the first light source substrate 201, the second light source substrate 202, and the third light source substrate 203, the first light source substrate 201, the second light source substrate 202, and the third light source substrate 203 are deformed respectively. And the change in the relative position of the plurality of light sources 220 can be reduced.

  Further, the first light source substrate 201, the second light source substrate 202, and the third light source substrate 203 are arranged so as to be shifted in the overlapping direction intersecting with the main scanning direction and the sub scanning direction, respectively. The size can be reduced.

  In addition, the first light source substrate 201 is coupled to the second light source substrate 202 adjacent in the overlapping direction and the third light source substrate 203 adjacent to each other in the overlapping direction in a state where heat conduction can be performed in the contact region 231 of the second light source substrate 202. And the contact region 231 of the first light source substrate 201 are coupled in a state where heat conduction is possible. For this reason, since it transfers between the 1st light source board | substrate 201, the 2nd light source board | substrate 202, and the 3rd light source board | substrate 203, the heat | fever emitted from the several light source 220 can be transferred efficiently.

  Further, since the first light source substrate 201 and the second light source substrate 202 are coupled via the contact member 241, and the first light source substrate 201 and the third light source substrate 203 are coupled via the contact member 241, it is efficient. Can transfer heat.

  In addition, the first light source substrate 201 is adjacent to the first coupling region 251 coupled to the second light source substrate 202 adjacent on the upper side where the overlapping direction is the first direction, and on the lower side where the overlapping direction is the second direction. A second coupling region 261 coupled to the three light source substrate 203, and the second light source substrate 202 includes a second coupling region 262 coupled to the first light source substrate 201 adjacent on the lower side where the overlapping direction is the second direction. The third light source substrate 203 includes a first coupling region 253 coupled to the first light source substrate 201 adjacent on the upper side where the overlapping direction is the first direction. In the first light source substrate 201, the second coupling region 261 is disposed between the first coupling region 251 and the plurality of light sources 220 in the sub-scanning direction. Since the first coupling region 251 of the first light source substrate 201 and the second coupling region 262 of the second light source substrate 202 are physically coupled by the first coupling member 281, the first light source substrate 201 and the second light source substrate 202 are combined. The distances in the sub-scanning direction of the plurality of light sources 220 included in each can be determined based on the position of the first coupling member 281. Similarly, since the second coupling region 261 of the first light source substrate 201 and the first coupling region 253 of the third light source substrate 203 are physically coupled by the second coupling member 282, the first light source substrate 201 and the third light source substrate 201 are coupled to each other. The distance in the sub-scanning direction of the plurality of light sources 220 included in each of the light source substrates 203 can be determined based on the position of the second coupling member 282. As a result, the distance in the sub-scanning direction between the plurality of light sources 220 of the first light source substrate 201 and the plurality of light sources 220 of the second light source substrate 202, the plurality of light sources 220 of the first light source substrate 201, and the third The distance in the sub-scanning direction between the light source substrate 203 and the plurality of light sources 220 can be made equal.

  Further, the distance in the sub-scanning direction between the plurality of light sources 220 of the first light source substrate 201 and the plurality of light sources 220 of the second light source substrate 202, the plurality of light sources 220 of the first light source substrate 201, and the third light source. The positions of the first coupling region 251 and the second coupling region 261 are set so that the distance in the sub-scanning direction between the substrate 203 and the plurality of light sources 220 is the same at a predetermined temperature. The relative positions of the plurality of light sources 220 of the second light source substrate 202 and the plurality of light sources 220 of the first light source substrate 201 are the distance L1 between the first coupling region 251 and the plurality of light sources 220 of the second light source substrate 202. The distance L3 between the first coupling region 251 and the second coupling region 261 and the distance L2 between the second coupling region 261 and the plurality of light sources 220 of the first light source substrate 201 are determined. The relative positions of the plurality of light sources 220 of the first light source substrate 201 and the plurality of light sources 220 of the third light source substrate 203 are the distance L2 between the second coupling region 261 and the plurality of light sources 220 of the first light source substrate 201. The distance L4 between the second coupling region 261 and the plurality of light sources 220 of the third light source substrate 203 is determined. For this reason, the intervals in the sub-scanning direction of the plurality of light sources 220 included in each of the first light source substrate 201, the second light source substrate 202, and the third light source substrate 203 can be made the same at a predetermined temperature.

  In addition, since the exposure apparatus 21Y in the modification includes the first positioning member 310A and the second positioning member 310B, the first light source substrate 201, the second light source substrate 202, and the third light source substrate 203 are thermally expanded due to temperature changes. Even in this case, the plurality of light sources 220 of the first light source substrate 201, the plurality of light sources 220 of the second light source substrate 202, and the plurality of light sources 220 of the third light source substrate 203 are respectively sub-scanned with the main body case 291. The relative position in the direction can be prevented from changing.

  Since the MFP 100 includes the exposure devices 21Y, 21M, 21C, and 21K, the change in the relative position of each of the light sources 220 of the exposure devices 21Y, 21M, 21C, and 21K is small, so that the image quality is stabilized. Therefore, MFP 100 can form an image with stable image quality.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

<Appendix>
(1) The exposure apparatus according to claim 1, wherein the distances in the sub-scanning direction of the optical axes of the plurality of light sources included in the plurality of light source substrates are arranged at a predetermined interval.
(2) In each of the plurality of light source substrates, the plurality of light sources are arranged at equal intervals,
The exposure apparatus according to claim 1, wherein the plurality of light source substrates are arranged such that optical axes of the plurality of light sources included in the plurality of light source substrates are shifted in the main scanning direction. Thereby, the resolution can be increased.

  100 MFP, 20Y, 20M, 20C, 20K Image forming unit, 21Y, 21M, 21C, 21K Exposure device, 23Y, 23M, 23C, 23K Photosensitive drum, 24Y, 24M, 24C, 24K Developer, 30 Intermediate transfer belt, 32 Fixing roller pair, 41Y, 41M, 41C, 41K Toner bottle, 110 main circuit, 120 automatic document feeder, 130 document reading unit, 140 image forming unit, 150 paper feeding unit, 155 post-processing unit, 160 operation panel, 201 First light source substrate, 202 Second light source substrate, 203 Third light source substrate, 220 Light source, 221, 222, 223 Rod lens array, 233 Circuit region, 231 Contact region, 232 Contact region, 241 Contact member, 251, 253 First Bonding region, 261, 262 Second bonding region, 28 DESCRIPTION OF SYMBOLS 1 1st coupling member, 282 2nd coupling member, 283 3rd coupling member, 291 Main body case, 301A, 301B, 302A, 302B, 303A, 303B Projection part, 310A 1st positioning member, 310B 2nd positioning member.

Claims (10)

A plurality of light source substrates each including a plurality of light sources arranged along the main scanning direction;
The plurality of light source substrates are arranged such that the optical axes of the plurality of light sources included in each of the plurality of light source substrates are shifted in a sub-scanning direction intersecting with the main scanning direction.   The exposure apparatus according to claim 1, wherein the plurality of light source substrates are arranged so as to be shifted in an overlapping direction intersecting with the main scanning direction and the sub-scanning direction, respectively.   3. The exposure apparatus according to claim 2, wherein each of the plurality of light source substrates is coupled to another light source substrate adjacent in the overlapping direction in a state where heat conduction is possible in a contact region.   The exposure apparatus according to claim 3, further comprising a contact member that couples each of the plurality of light source substrates to another light source substrate in the contact area.   5. The exposure apparatus according to claim 2, wherein each of the plurality of light source substrates is physically coupled to another light source substrate adjacent in the overlapping direction in a coupling region. Each of the plurality of light source substrates includes a first coupling region coupled with the light source substrate adjacent in the overlapping direction in the first direction, and the light source substrate adjacent in the second direction opposite to the first direction in the overlapping direction. A second binding region to be joined,
6. The exposure apparatus according to claim 5, wherein in each of the plurality of light source substrates, the second coupling region is disposed between the first coupling region and the plurality of light sources in the sub-scanning direction.   In each of the plurality of light source substrates, the distance between the plurality of light sources of the light source substrate and the plurality of light sources of the light source substrate adjacent in the overlapping direction in the first direction, and the plurality of the light source substrates The distance between the light source and the plurality of light sources of the light source substrate that are adjacent in the second direction in the overlapping direction is the same at a predetermined temperature, and the first coupling region and the second The exposure apparatus according to claim 6, wherein a position of the combined area is set.   5. The positioning device according to claim 1, further comprising a positioning unit that positions each of the plurality of light source substrates in the sub-scanning direction at the same position in the sub-scanning direction as the plurality of light sources included in the light source substrate. The exposure apparatus described in 1.   The exposure apparatus according to claim 1, further comprising a plurality of optical elements that respectively correspond to the plurality of light source substrates and condense light emitted from the plurality of light sources onto a subject.   An image forming apparatus comprising the exposure apparatus according to claim 1.

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