Exposure device and image formation device

Abstract

To perform adjustment of a position of a substrate, a quantity of light or the like while minimizing deflection of a part on which light emitters of the substrate are mounted.SOLUTION: An exposure device which has a long shape extending in the axial direction of a photoreceptor, and exposes the photoreceptor includes: a substrate on which a plurality of light emitters emitting light for exposing the photoreceptor are aligned along the axial direction; a lens array for condensing light emitted from the light emitters to the photoreceptor; a holding body for holding the substrate and the lens array; a first contact point electrically connected with the light emitters, and inputting a signal of controlling light emission of the light emitters through a contact terminal contacted in connectable and separable states; and a second connection point disposed in a position different from that of the first connection point in the longitudinal direction of the substrate, electrically connected with the light emitters and inputting a signal of controlling light emission of the light emitters through the contact terminal contacted in connectable and separable states.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an exposure device that exposes a photosensitive member to light and an image forming apparatus that includes the exposure device. [Background technology]

[0002] Conventionally, electrophotographic image forming devices have been widely used, which use an exposure device equipped with an LED array and a lens array to form an electrostatic latent image on the surface of a photosensitive member, and then develop the toner image by attaching toner to the electrostatic latent image (Patent Document 1).

[0003] In conventional exposure devices, a substrate on which an LED array is mounted is adhered to a holder with an adhesive, and the gap between the substrate and the holder is sealed with a sealant. Furthermore, the substrate on which the LED array is mounted is electrically connected to the main body control unit of the image forming apparatus using a flexible flat cable (hereinafter also referred to as FFC). A connector is mounted on the substrate on which the LED array is mounted, and the FFC is removably connected to the connector mounted on this substrate, thereby electrically connecting the substrate to the main body control unit of the image forming apparatus.

[0004] Furthermore, in conventional exposure devices, the position of the substrate, the amount of light, etc. are adjusted using tools as part of the assembly process before bonding with adhesive or after sealing with sealant. In this process, FFC is used to electrically connect the substrate and the tools, just like in image forming devices, and the position of the substrate, the amount of light, etc. are adjusted. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-62853 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when adjusting the exposure equipment during the assembly process, the force applied to the board when inserting and removing the FFC could cause bending in the part of the board where the LED array is mounted.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to make it possible to adjust the position and light intensity of the board while minimizing the bending of the portion of the board on which the LED array is mounted. [Means for solving the problem]

[0008] A typical configuration of the present invention is an exposure device that has an elongated shape extending in the axial direction of a photosensitive body and exposes the photosensitive body, and is characterized by comprising: a substrate on which a plurality of light-emitting elements that emit light to expose the photosensitive body are arranged along the axial direction; a lens array that focuses the light emitted from the light-emitting elements onto the photosensitive body; a holder that holds the substrate and the lens array; a first contact that is electrically connected to the light-emitting elements and inputs a signal that controls the light emission of the light-emitting elements through a contact terminal that is releasably contacted; and a second contact that is provided at a position different from the first contact in the longitudinal direction of the substrate, is electrically connected to the light-emitting elements and inputs a signal that controls the light emission of the light-emitting elements through a contact terminal that is releasably contacted. [Effects of the Invention]

[0009] According to the present invention, it is possible to adjust the position of the board, the amount of light, etc., while minimizing the bending of the portion of the board on which the light emitting element is mounted. [Brief explanation of the drawings]

[0010] [Figure 1] (a), (b), (c), and (d) are explanatory diagrams of a substrate according to an embodiment. [Figure 2] Schematic cross-sectional view of an image forming apparatus [Figure 3] FIG. 1 is a perspective view of an optical print head provided in an image forming apparatus, seen from above; [Figure 4] (a), (b), and (c) are diagrams showing the substrate, and (d) and (e) are diagrams showing the lens array. [Figure 5] FIG. 1 is an enlarged view of the connector and check pad portions of the board according to the embodiment. [Figure 6] Cross-sectional view showing the configuration of an optical print head [Figure 7] Perspective view of the optical print head from below [Figure 8] Enlarged view of the connector side of the optical print head [Figure 9] 1A and 1B are diagrams showing the relationship between the check pad and the sealant according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail by way of example with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in the following embodiments may be changed as appropriate depending on the configuration of the device to which the present invention is applied and various conditions, and are not intended to limit the scope of the present invention to those alone.

[0012] (Image forming device) First, a schematic configuration of the image forming apparatus 1 will be described. Fig. 2 is a schematic cross-sectional view of the image forming apparatus 1. The image forming apparatus 1 shown in Fig. 2 is a color printer (MFP: Multi Function Printer) equipped with a reading device, but the embodiment may also be a copier that does not have a reading device. Furthermore, the embodiment is not limited to a so-called tandem color image forming apparatus equipped with multiple photosensitive drums 103 as shown in Fig. 2, but may also be a color image forming apparatus equipped with one photosensitive drum 103 or an image forming apparatus that forms monochrome images.

[0013] The image forming apparatus 1 shown in FIG. 2 includes four image forming units 102Y, 102M, 102C, and 102K (hereinafter also collectively referred to simply as "image forming units 102") that form toner images of yellow, magenta, cyan, and black, respectively.

[0014] The image forming units 102Y, 102M, 102C, and 102K are provided with photosensitive drums 103Y, 103M, 103C, and 103K (hereinafter also collectively referred to simply as "photosensitive drums 103"), respectively. These photosensitive drums are arranged at a distance from each other.

[0015] The image forming units 102Y, 102M, 102C, and 102K are also provided with chargers 104Y, 104M, 104C, and 104K (hereinafter also collectively referred to simply as "charger 104") that charge the photosensitive drums 103Y, 103M, 103C, and 103K, respectively.

[0016] The image forming units 102Y, 102M, 102C, and 102K are also provided with exposure units 500Y, 500M, 500C, and 500K (hereinafter collectively referred to as "exposure units 500") that expose the photosensitive drums 103Y, 103M, 103C, and 103K to light. The image forming apparatus 1 shown in Fig. 2 is a so-called "bottom exposure type" image forming apparatus that exposes the photosensitive drum 103 from below.

[0017] Furthermore, the image forming units 102Y, 102M, 102C, and 102K are equipped with developing units 106Y, 106M, 106C, and 106K (hereinafter collectively referred to as "developing units 106") that develop the electrostatic latent image on the photosensitive drum 103 with toner and develop toner images of the respective colors on the photosensitive drum 103. The letters Y, M, C, and K attached to the reference characters indicate the colors of the toner (yellow, magenta, cyan, and black).

[0018] The image forming apparatus 1 includes an intermediate transfer belt 107 onto which a toner image formed on a photosensitive drum 103 is transferred, and primary transfer rollers 108 (Y, M, C, K) that sequentially transfer the toner images formed on the photosensitive drum 103 onto the intermediate transfer belt. The image forming apparatus 1 also includes a secondary transfer roller 109 that transfers the toner image on the intermediate transfer belt 107 onto a recording material S conveyed from a paper feed unit 101, and a fixing device 100 that fixes the secondarily transferred image onto the recording material S.

[0019] After the primary transfer, toner remains on the surfaces of the photosensitive drums 103Y, 103M, 103C, and 103K. This residual toner is removed by drum cleaning devices (first cleaning devices) 8Y, 8M, 8C, and 8K (hereinafter, also collectively referred to as "drum cleaning devices 8") and collected in the collected toner container 5.

[0020] After the secondary transfer, toner remains on the surface of the intermediate transfer belt 107. This remaining toner is removed by a belt cleaning device (second cleaning device) 7 and collected in a collected toner container 5.

[0021] (Image formation process) Next, a brief description will be given of the image formation process of the image forming apparatus. The charger 104Y charges the surface of the photosensitive drum 103Y. The exposure unit 500Y exposes the surface of the photosensitive drum 103Y charged by the charger 104Y. This forms an electrostatic latent image on the photosensitive drum 103Y. Next, the developer 106Y develops the electrostatic latent image formed on the photosensitive drum 103Y with yellow toner. The yellow toner image developed on the surface of the photosensitive drum 103Y is transferred onto the intermediate transfer belt 107 by the primary transfer roller 108Y. Magenta, cyan, and black toner images are formed in a similar image formation process and transferred to the intermediate transfer belt 107 so as to be superimposed on top of each other.

[0022] The toner images of each color transferred onto the intermediate transfer belt 107 are transported to a secondary transfer section T2 by the intermediate transfer belt 107. A transfer bias is applied to a secondary transfer roller 109 disposed at the secondary transfer section T2 to transfer the toner images onto the recording material S. The toner images transported to the secondary transfer section T2 are transferred onto the recording material S transported from a paper feed section (paper feed cassette) 101 by the transfer bias of the secondary transfer roller 109.

[0023] The recording material S is stored in a stacked form in the paper feed unit 101 and is fed to the conveying path 20 in accordance with the image formation timing. The paper feeding method involves first flipping up the leading edge of the recording material S due to friction of the paper feed roller 80, and then conveying only one sheet of recording material S to the conveying path 20 by a pair of paper separating conveying rollers 9a, 9b to prevent double feeding of the recording material S. The recording material S is then pulled out by the pair of conveying rollers 10a, 10b, and conveyed through the conveying path 20 to the pair of registration rollers 11a, 11b, where it is temporarily stopped. Note that the pair of registration rollers 11a, 11b perform skew correction and timing correction before conveying the recording material to the secondary transfer unit T2.

[0024] The recording material S onto which the toner image has been transferred at the secondary transfer unit T2 is conveyed to the fixing unit 100. The fixing unit 100 fixes the toner image onto the recording material S by heat and pressure. The recording material S that has been subjected to the fixing process by the fixing unit 100 is discharged to the paper discharge unit 111.

[0025] 2, the image forming apparatus 1 is also provided with toner containers 4Y, 4M, 4C, and 4K (hereinafter, collectively referred to as "toner containers 4"). When an image is formed, the amount of toner in the developing device 106 decreases. When this occurs, toner is supplied to the developing device 106 from the toner containers 4Y, 4M, 4C, and 4K provided corresponding to the image forming units 102Y, 102M, 102C, and 102K via pipes (not shown).

[0026] (Basic configuration of optical print head) Next, the optical print head (exposure head, exposure device) 105 provided in the exposure unit 500 will be described. Here, one example of an exposure method adopted in an electrophotographic image forming apparatus is a laser beam scanning exposure method in which a semiconductor laser irradiation beam is scanned by a rotating polygon mirror or the like and the photosensitive drum is exposed via an f-θ lens or the like. The "optical print head 105" described in this embodiment is used in an LED exposure method in which the photosensitive drum 103 is exposed to light emitting elements such as LEDs arranged along the rotation axis direction of the photosensitive drum 103, but is not used in the laser beam scanning exposure method mentioned above.

[0027] The optical print head 105 described in this embodiment is provided vertically below the rotation axis of the photosensitive drum 103, and the LEDs 503 included in the optical print head 105 expose the photosensitive drum 103 from below. Figure 3 is a perspective view of the optical print head 105 included in the image forming apparatus 1 of this embodiment, viewed from above.

[0028] The optical print head (exposure head) 105 has an elongated shape (longitudinal shape) extending in the direction of the rotation axis of the photosensitive drum 103. The optical print head 105 includes a substrate 502, a light-emitting element mounted on the substrate 502, a lens array 506, and a holder 54 that holds the substrate 502 and the lens array 506. Here, the optical print head 105 includes an LED 503 (Light Emitting Diode, hereinafter referred to as LED) as a light-emitting element that emits light (see FIG. 4(c)). The substrate 502 is installed inside the holder 54. The holder 54 is provided with a lens attachment portion (first opening 54a in FIG. 6) for attaching the lens array 506.

[0029] The holder 54 is a thin metal plate about 1 mm thick, and is a part made by pressing an electro-galvanized steel plate.

[0030] The lens attachment portion of the holder 54 (first opening 54a in FIG. 6) is an opening slightly larger than the lens array 506, and the lens array 506 is fixed to the holder 54 with an adhesive (not shown). The substrate 502 is formed slightly smaller than the holder 54, and the position of the substrate 502 is adjusted so that the optical axis of the LEDs 503 is aligned with the center of the lens array 506. Thereafter, the substrate 502 is fixed to the holder 54 with an adhesive (not shown) between the wall surfaces on both sides of the substrate 502 in the short direction of the holder 54 (the direction perpendicular to the long direction). This adhesive is, for example, an ultraviolet-curing adhesive, and is applied to the bonding location in a liquid or gel state and then cured by irradiation with ultraviolet light.

[0031] The substrate 502 held by the holder 54 will now be described. Fig. 4(a) is a schematic perspective view of the substrate 502. Fig. 4(b) shows the arrangement of a plurality of LEDs 503 provided on the substrate 502. Fig. 4(c) is an enlarged view of Fig. 4(b).

[0032] An LED chip 639 is mounted on the substrate 502. As shown in FIG. 4(a), the LED chip 639 is provided on one surface of the substrate 502, and a long FFC connector 504 is provided on the other surface (the surface opposite to the side on which the light-emitting elements are arranged). The FFC connector 504 is attached to the lower surface of the substrate 502 so that its longitudinal direction is along the longitudinal direction of the substrate 502. Wiring is provided on the substrate 502 for supplying signals to each LED chip 639. One end of a flexible flat cable (hereinafter also referred to as FFC) 160, which is an example of a cable, is removably connected to the connector 504.

[0033] The main body of the image forming apparatus 1 is provided with a control board (not shown) that includes a control unit and a connector. The other end of the FFC 160 is connected to the connector provided on the control board. That is, the FFC 160 electrically connects the control board (control unit) of the main body of the image forming apparatus 1 to the board 502 of the optical print head 105. A control signal (drive signal) is input to the board 502 from the control unit of the main body of the image forming apparatus 1 via the FFC 160 and the connector 504. The LED chip 639 is driven by the control signal input to the board 502.

[0034] The LED chip 639 mounted on the substrate 502 will now be described. As shown in FIGS. 4(b) and 4(c), a plurality of LED chips 639-1 to 639-29 (29 chips) each having a plurality of LEDs 503 (an example of a light-emitting element) arranged thereon are arranged on one surface of the substrate 502. Each of the LED chips 639-1 to 639-29 has 516 LEDs 503 arranged in a row in its longitudinal direction. In the longitudinal direction of the LED chip 639, the center-to-center distance k2 between adjacent LEDs 503 corresponds to the resolution of the image forming apparatus 1.

[0035] The LED chips 639-1 to 639-29 are alternately arranged in two rows along the rotation axis direction of the photosensitive drum 103. That is, as shown in FIG. 4(b), the odd-numbered LED chips 639-1, 639-3, ..., 639-29 counting from the left are mounted in a row in the longitudinal direction of the substrate 502, and the even-numbered LED chips 639-2, 639-4, ..., 639-28 are mounted in a row in the longitudinal direction of the substrate 502. By arranging the LED chips 639 in this manner, as shown in FIG. 4(c), the center-to-center distance k1 between the LEDs arranged between one end of one LED chip 639 and the other end of the other LED chip 639 in adjacent different LED chips 639 in the longitudinal direction of the LED chips 639 can be made equal to the center-to-center distance k2 between adjacent LEDs 503 on one LED chip 639.

[0036] In this embodiment, the light-emitting elements (light-emitting portions) are semiconductor LEDs, which are light-emitting diodes, but they may also be, for example, OLEDs (Organic Light Emitting Diodes). OLEDs are also called organic ELs (Organic Electro-Luminescence) and are current-driven light-emitting elements. The OLEDs are arranged in a line along the main scanning direction (the axial direction of the photosensitive drum 2) on a TFT (Thin Film Transistor) substrate, for example, and are electrically connected in parallel by power supply wiring that is also provided along the main scanning direction.

[0037] Next, the lens array 506, which is a lens assembly, will be described. FIG. 4(d) is a schematic diagram of the lens array 506 as viewed from the photosensitive drum 103 side. FIG. 4(e) is a schematic perspective view of the lens array 506. As shown in FIG. 4(d), the lens array 506 focuses light emitted from the light-emitting elements onto the photosensitive drum 103. The lens array 506 is a lens assembly having a plurality of lenses. These lenses are arranged in two rows along the arrangement direction of the plurality of LEDs 503. The lenses are alternately arranged such that one lens in one row is in contact with both of the lenses adjacent to the other row in the arrangement direction of the lenses in the other row. Each lens is a cylindrical glass rod lens. Note that the material of the lenses is not limited to glass and may be plastic. The shape of the lenses is also not limited to cylindrical and may be a polygonal prism, such as a hexagonal prism.

[0038] The dotted line Z in Figure 4(e) indicates the optical axis of the lens. The optical print head 105 can be moved in a direction generally along the optical axis of the lens indicated by the dotted line Z (hereinafter also referred to as the optical axis direction) by a movement mechanism (not shown). The optical axis of the lens here refers to the line connecting the center of the light-emitting surface of the lens to the focal point of the lens. The lens array 506 is a lens assembly having multiple lenses, and the aforementioned "optical axis" refers to the optical axis of any of these lenses. Strictly speaking, the multiple lenses in the lens array 506 may be slightly tilted relative to each other. This is due to assembly tolerances. However, deviations within the tolerance range mentioned here will not be taken into account when defining the direction of the optical axis. Therefore, the optical axes of the multiple lenses are considered to be in the same direction. The lens array 506 serves to focus light emitted from the LED 503 onto the surface of the photosensitive drum 103. That is, the light emitted from the LED 503 is incident on the lenses in the lens array 506. The lens has a function of converging the incident radiation onto the surface of the photosensitive drum 103 .

[0039] The attachment position of the lens array 506 relative to the lens attachment portion (first opening 54a in FIG. 6) is adjusted when assembling the optical print head 105. Specifically, the attachment position of the lens array 506 relative to the lens attachment portion (first opening 54a in FIG. 6) is adjusted so that the distance between the light-emitting surface of the LED 503 and the light-incident surface of the lens is approximately equal to the distance between the light-exiting surface of the lens and the surface of the photosensitive drum 103.

[0040] (Board configuration) Next, the configuration of the substrate 502 will be described in more detail with reference to FIGS. 1(a), 1(b), 1(c), 3, and 5. FIG.

[0041] Fig. 1(a) is a view of the substrate 502 seen from the connector 504 side. Fig. 1(b) is a view of the substrate 502 seen from the LED chip 639 side. Fig. 1(c) is a view of the substrate 502 seen from the thickness direction. Fig. 5 is an enlarged view of the connector 504 and check pad 601 portions of the substrate 502.

[0042] As shown in FIGS. 1(a) to 1(c), the substrate 502 has a longitudinal shape extending in the axial direction of the photosensitive drum 103.

[0043] As shown in Figures 1(b) and 1(c), the substrate 502 is provided with a plurality of LED chips 639 on which a plurality of LEDs 503 are arranged, and the LED chips 639 are mounted on one surface of the substrate 502.

[0044] 1(a), the substrate 502 includes an IC 600 that controls the light emission of the LED chip 639. The IC 600 is mounted on the surface of the substrate 502 opposite to the surface on which the LED chip 639 is mounted. The IC 600 is electrically connected to the LED chip 639.

[0045] As described above, the substrate 502 is provided with wiring (not shown) for supplying signals to the LED chips 639. Among the wiring provided on the substrate 502, a plurality of wirings (not shown) for supplying control signals for controlling the light emission of each LED chip 639 are connected to the IC 600. The plurality of wirings connected to the IC 600 are connected to each LED chip 639. In this way, the IC 600 is electrically connected to the LED chips 639 by the wiring provided on the substrate 502.

[0046] 1(a) and 1(c), the substrate 502 is provided with an FFC connector 504 to which the FFC 160 is removably connected. The FFC connector 504 is mounted on the surface of the substrate 502 opposite to the surface on which the LED chip 639 is mounted. The FFC connector 504 is electrically connected to the LED chip 639.

[0047] Among the wirings of the substrate 502 described above, wiring (not shown) that supplies a control signal for controlling the light emission of the LED chip 639 is connected to the FFC connector 504. The wiring that supplies the control signal, connected to the FFC connector 504, is connected to the IC 600. That is, the FFC connector 504 is electrically connected to the LED chip 639 via the IC 600.

[0048] Furthermore, among the wirings of the aforementioned substrate 502, wiring (not shown) that supplies power to control the light emission of the LED chips 639 is connected to the FFC connector 504. The wiring that supplies power, connected to this FFC connector 504, is connected in parallel to each LED chip 639. The wiring that supplies power, connected to this FFC connector 504, is connected directly to the LED chips 639 without going through the IC 600.

[0049] (contacts on the board) 1(a), the substrate 502 further includes a first check pad 601 as a first contact point and a second check pad 701 as a second contact point, in addition to the FFC connector 504. The second check pad 701 is provided at a different position from the first check pad 601 in the longitudinal direction of the substrate 502.

[0050] (First check pad) A plurality of first check pads 601 are provided. In other words, the first check pads 601 include a plurality of contact points. The first check pads 601 are provided on the surface of the substrate 502 opposite to the surface on which the LED chip 639 is mounted. The first check pads 601 are copper foil portions provided on the substrate 502, and are contact points with which a contact probe (not shown) serving as a contact terminal connected to an adjustment tool, which will be described later, comes into detachable contact. A signal for controlling the light emission of the LED chip 639 is input to the first check pad 601 through the contact probe (not shown) serving as a contact terminal that comes into detachable contact with the first check pad 601.

[0051] 5, the multiple first check pads 601 are electrically connected to the LED chip 639. As shown in FIG. 5, the multiple first check pads 601 are each electrically connected to the FFC connector 504 by wiring 603 provided on the substrate 502. The multiple wiring 603 connecting the first check pads 601 and the FFC connector 504 includes wiring that supplies a control signal that controls the light emission of the LED chip 639, and wiring that supplies power that controls the light emission of the LED chip 639.

[0052] In other words, the plurality of first check pads 601 include contacts connected to wiring that is connected to the FFC connector 504 and supplies a control signal that controls the light emission of the LED chip 639. The plurality of first check pads 601 also include contacts connected to wiring that is connected to the FFC connector 504 and supplies a power source that controls the light emission of the LED chip 639.

[0053] As shown in FIG. 1(a), the first check pad 601 is disposed at one end of the substrate 502 in the longitudinal direction.

[0054] The first check pad 601 is disposed closer to the end than the FFC connector 504 in the longitudinal direction of the substrate 502. In this embodiment, the FFC connector 504 is disposed closer to one end than the center in the longitudinal direction of the substrate 502, as shown in FIG. 1(a), and the first check pad 601 is disposed closer to the end than the FFC connector 504.

[0055] In addition, since the substrate 502 shown in FIG. 1(a) is configured such that the FFC connector 504 is positioned closer to the end of the substrate 502 in the longitudinal direction than the IC 600, it can also be said that the first check pad 601 is positioned closer to the end of the substrate 502 in the longitudinal direction than the IC 600.

[0056] 1(b), the first check pad 601 is disposed on the front and back surfaces of the substrate 502 at a position that does not overlap the area where the LED chip 639 of the substrate 502 is mounted. In other words, the first check pad 601 is disposed at a position that does not overlap the LED chip 639 in the longitudinal direction of the substrate 502. Furthermore, the first check pad 601 is disposed outside the area where the LED chip 639 of the substrate 502 is mounted in the longitudinal direction of the substrate 502.

[0057] At least some of the multiple first check pads 601 are arranged side by side in the short direction perpendicular to the long direction of the substrate 502. Here, as shown in Figure 1(a), a configuration in which four first check pads 601 are arranged is shown as an example. The four first check pads 601 are arranged in two rows (multiple rows) in the short direction.

[0058] (Second check pad) Like the first check pads 601, a plurality of second check pads 701 are provided. In other words, the second check pads 701 include a plurality of contact points. The second check pads 701 are provided on the surface of the substrate 502 opposite to the surface on which the LED chip 639 is mounted. The second check pads 701 also have the same function as the first check pads 601. That is, the second check pads 701 are copper foil portions provided on the substrate 502, and are contact points with which a contact probe (not shown) serving as a contact terminal connected to an adjustment tool (described later) can be brought into detachable contact. The second check pads 701 are contact points provided separately from the first check pads 601. A signal for controlling the light emission of the LED chip 639 is input to the second check pad 701 through the contact probe (not shown) serving as a contact terminal that can be brought into detachable contact with the second check pad 701.

[0059] Similar to the above-described first check pads 601, the multiple second check pads 701 are also electrically connected to the LED chip 639. The electrical connection of the multiple second check pads 701 is similar to the electrical connection of the above-described first check pads 601, and therefore a description thereof will be omitted here.

[0060] The second check pad 701 is arranged further inward than the first check pad 601 in the longitudinal direction of the substrate 502. Here, as shown in FIG. 1(a), the second check pad 701 is arranged in the center of the substrate 502 in the longitudinal direction.

[0061] All of the multiple second check pads 701 are arranged in a row in the longitudinal direction of the substrate 502. Here, as shown in Figure 1(a), a configuration in which four second check pads 701 are arranged is shown as an example. The four second check pads 701 are arranged in a row in the longitudinal direction.

[0062] As described above, the FFC connector 504 is electrically connected to the IC 600 by wiring that supplies a control signal, and is electrically connected to the LED chip 639 by wiring that supplies power. The IC 600 is further electrically connected to the LED chip 639 by wiring that supplies a control signal. In this way, the first check pad 601 and the second check pad 701 are electrically connected to the LED chip via the FFC connector 504 by wiring that the substrate 502 has.

[0063] (Adjusting the position of the board and the amount of light) As described above, the substrate 502 is adhesively fixed to the holder 54 with an adhesive when assembling the optical print head 105. Before the substrate 502 is adhesively fixed to the holder 54, the substrate 502 is electrically connected to a tool (not shown) and the position of the substrate 502, the amount of light, etc. are adjusted. The first check pad 601 provided on the substrate 502 is used when adjusting the position of the substrate 502, the amount of light, etc.

[0064] Of the multiple contacts that the substrate 502 according to this embodiment has, the first check pad 601 as the first contact is, as described above, disposed at one end in the longitudinal direction of the substrate 502. The first check pad 601 is also disposed at a position on the front and back surfaces of the substrate 502 that does not overlap with the area where the LED chip 639 of the substrate 502 is mounted.

[0065] During the above-mentioned adjustment when assembling the optical print head 105, as shown in Fig. 1(c), the substrate 502 is first sucked by suction pads 602 at multiple locations in the longitudinal direction of the substrate 502 to correct any warping or bending of the substrate 502. Then, a contact probe (not shown) electrically connected to a tool is brought into contact with a first check pad 601 provided on the substrate 502.

[0066] Although not shown, for example, contact probes are used in which the same number of probes as the first check pads 601 are fixed to a support member in accordance with the positions of the first check pads 601. Each probe has a contact rod (plunger) that comes into contact with the check pad supported slidably in a hollow cylindrical member (barrel, pipe), and is biased in the direction of movement by a biasing member (spring) provided inside the cylindrical member. With this configuration, even if the substrate 502 is moved to adjust the position, the contact rod of the probe strokes in accordance with the movement of the substrate 502, so that the probe and first check pad 601 do not separate and the contact state is maintained.

[0067] To maintain this contact state, a pressing force F of the probe acts on the substrate 502. In this embodiment, as shown in FIG. 1(a), the first check pad 601 is arranged at one end in the longitudinal direction of the substrate 502. Therefore, the pressing force F of the probe (FIG. 1(c)) is generated at the end in the longitudinal direction of the substrate 502 where the first check pad 601 is arranged, and portions of the substrate 502 other than this end are less susceptible to the pressing force F of the probe. As a result, according to this embodiment, it is possible to suppress the effects of bending of the portion of the substrate 502 on which the LED chip 639 is mounted, which is caused by the pressing force F being applied to the substrate 502.

[0068] Furthermore, in this embodiment, the first check pad 601 is arranged outside the mounting area of ​​the LED chip 639 on the substrate 502. Therefore, the influence of the bending of the portion of the substrate 502 on which the LED chip 639 is mounted, which is caused by the application of the pressure force F to the substrate 502, can be minimized.

[0069] During the above-described adjustment, it is also possible to use the FFC 160 instead of the first check pad 601. However, if the FFC 160 is used during the adjustment, the FFC 160 must be inserted into and removed from the FFC connector 504. Because the board 502 on which the LED chip 639 is mounted is long, the force applied to the board 502 when inserting or removing the FFC 160 may cause bending in the portion of the board 502 on which the LED chip 639 is mounted. In particular, if the FFC connector 504 overlaps the mounting area of ​​the LED chip 639 on the front and back surfaces of the board 502, excessive force may be applied to the mounting area of ​​the LED chip 639 on the board 502, potentially causing greater bending in the portion of the board on which the LED array is mounted.

[0070] The substrate 502 according to this embodiment is provided with a first check pad 601 separate from the FFC connector 504. The pressing force F of the contact probe (not shown) acting on the substrate 502 is within a range that maintains contact when adjusting the position of the substrate, and is therefore much smaller than the force required to insert or remove the FFC 160 from the FFC connector 504, which has the force to hold the FFC 160. That is, the pressing force F of the contact probe (not shown) acting on the substrate 502 is much smaller than the force applied to the substrate 502 when inserting or removing the FFC connector 504. Furthermore, in a configuration in which the contact probe (not shown) is separated from the first check pad 601 as in this embodiment, no force is applied to the substrate 502 when the FFC 160 is removed. Therefore, it is possible to minimize the effect of bending of the portion of the substrate on which the LED chip is mounted, which would be caused by excessive force being applied to the substrate.

[0071] In this way, a signal that controls the light emission of LED chip 639 is input to substrate 502 through the electrical connection between the contact probe and first check pad 601, and the position of substrate 502 is adjusted while LED chip 639 of substrate 502 is emitting light. Once the position has been determined, substrate 502 is adhered and fixed to holder 54 with an adhesive.

[0072] (sealing optical print head) When assembling the optical print head, the substrate 502 is adhesively fixed to the holder 54, and the gap between the substrate 502 and the holder 54 is further sealed with a sealant.

[0073] As described above, the lens array 506 is also adhered and fixed to the holder 54 with an adhesive, just like the substrate 502. The gap between this lens array 506 and the holder 54 is also sealed with a sealant.

[0074] Sealing of optical print head 105 with a sealant will be described using Figures 3 and 6 to 8. Figure 6 is a cross-sectional view showing the configuration of optical print head 105. Figure 7 is a perspective view of optical print head 105 from below, with substrate 502 attached to holder 54. Figure 8 is an enlarged view of the connector side (front side) of optical print head 105 shown in Figure 7.

[0075] As shown in Fig. 6, the holder 54 holds the lens array 506 and the substrate 502. In this embodiment, the holder 54 is a metal member formed by bending a plated material such as a zinc-plated steel plate or a cold-rolled steel plate. For example, the holder 54 is formed by pressing a metal plate such as a thin iron plate into a U-shape. The shape of the holder 54 will be described below.

[0076] 6, the holder 54 has a flat portion (facing surface) 54U in which a first opening 54a into which the lens array 506 is inserted is formed. The flat portion 54U faces the photosensitive drum 103 in the optical axis direction of the lenses of the lens array 506. Note that this flat portion 54U is not limited to a flat surface, and may be a slightly curved surface. The holder 54 also has an extension portion 54R that extends from one side of the flat portion 54U in the widthwise direction in a direction away from the photosensitive drum 103. The holder 54 also has an extension portion 54L that extends from the other side of the flat portion 54U in the widthwise direction in a direction away from the photosensitive drum 103.

[0077] The extending portions 54R and 54L form a substrate support portion of the holder 54 for supporting the substrate 502 inserted through the second opening 54b. The flat portion 54U and the substrate support portions (extending portions 54R, 54L) are integral and form the holder 54 that holds the lens array 506 and the substrate 502, and its cross section is formed in a substantially U-shape. By forming the holder 54 in a substantially U-shape, a second opening 54b is formed on the opposite side to the flat portion 54U. The second opening 54b is formed between the substrate support portions (extending portions 54L, 54R) that extend from the flat portion 54U to the side away from the photosensitive drum.

[0078] Substrate 50 is inserted from second opening 54b, i.e., from the lower side of U-shaped holder 54, and is adhered with adhesive to the inside of each substrate support portion (the inside of extension portion 54L and the inside of extension portion 54R). Note that, because the position of substrate 502 in the focal direction is determined by a jig (not shown), optical print head 105 does not include a positioning means for substrate 50 in the focal direction.

[0079] The lens array 506 is also inserted into the first opening 54a formed in the flat portion 54U and bonded to the flat portion 54U with an adhesive. The lens array 506 is fixed to the flat portion 54U (holding body 54) after its position and inclination in the focusing direction are adjusted using a jig so that the distance in the focusing direction between all of the LED chips 639 mounted on the substrate 50 and the lens array 506 is a predetermined value. The lens array 506 is also fixed to the flat portion 54U with an adhesive at multiple locations in the longitudinal direction. That is, the optical print head 105 of this embodiment has multiple bonding locations in the longitudinal direction of the flat portion 54U where the lens array 506 inserted into the first opening 54a is adhesively fixed to the flat portion 54U.

[0080] After the substrate 502 and lens array 506 are positioned and fixed relative to the holder 54, the gap between the substrate 502 inserted into the second opening 54b and the holder 54 (extensions 54L and 54R) is sealed in the longitudinal direction with a sealant 59, as shown in FIGS. 7 and 8. The gap between the substrate 502 and the holder 54 is also sealed in the lateral direction with the sealant, and the gap between the periphery of the substrate 502 and the holder 54 is also sealed with the sealant. This prevents the LED 503 from being contaminated by external toner or dust. Here, the sealant 59 only seals the gap (boundary) between the substrate 502 and the holder 54, leaving most of the FFC connector 504 and the substrate 502 exposed.

[0081] Similarly, a sealant 59 is applied to the gap between the lens array 506 inserted into the first opening 54a and the holder 54 (flat portion 54U), and the gap is sealed in the longitudinal direction by the sealant 59, as shown in FIG. 3. More specifically, as shown in FIG. 3, the sealant 59 seals the gap between the side wall of the lens array 506 along the longitudinal direction of the holder 54 and the edge of the first opening 54a. This reduces the possibility that dust such as toner will enter through the gap between the side wall of the lens array 506 and the edge of the first opening 54a and block the light emitted from the LED 503. Naturally, the gap sealed by the sealant 59 not only seals the gap between the side wall on one side of the lens array 506 and the edge of the first opening 54a, but also seals the gap between the side wall on the other side of the lens array 506 and the edge of the first opening 54a. The other side wall of the lens array 506 refers to the side wall opposite to the one side side wall of the lens array 506. Here too, the gap (boundary) between the holder 54 and the lens array 506 is sealed with a sealant 59. This prevents the LEDs 503 from being contaminated by toner or dust from the outside.

[0082] (Optical print head inspection) As described above, optical print head 105, which has been completed up to the stage of sealing with sealant 59, is electrically connected to substrate 502 with a tool (not shown) and inspected for imaging conditions and other issues before being assembled into image forming apparatus 1. This is an inspection process in which the completed optical print head 105 is inspected for functional defects that may occur during bonding and sealing after adjusting the position of substrate 502 and lens array 506, as well as in subsequent processes, and the final light intensity adjustment is also performed. Second check pad 701 provided on substrate 502 is used when inspecting optical print head 105 before assembly.

[0083] Of the multiple contacts that the substrate 502 according to this embodiment has, the second check pad 701 serving as the second contact is, as described above, arranged more inward than the first check pad 601 in the longitudinal direction of the substrate 502. Here, the second check pad 701 is arranged in the center of the substrate 502.

[0084] On the other hand, as described above, the first check pad 601 is disposed at the longitudinal end of the substrate 502. This minimizes the effect of the pressure of the contact probe (not shown) on the portion of the substrate 502 on which the LED chip 639 is mounted or on the entire optical print head 105 that is deflected. However, the gap between the substrate 502 and the holder 54 around its periphery is sealed with the sealant 59. During sealing with the sealant 59, there is a possibility that the sealant 59 will be applied to one of the multiple first check pads 601. In particular, if multiple first check pads 601 are arranged side by side in the lateral direction of the substrate 502, the distance between the sealant 59 and the first check pads 601 cannot be ensured, increasing the possibility that the sealant 59 will be applied unintentionally to the first check pads 601. Therefore, there is a risk that the first check pads 601 will not be usable during pre-shipment inspection, which is performed after sealing with the sealant 59 to check the imaging state.

[0085] Therefore, in this embodiment, a second check pad 701 is provided on the substrate 502 in addition to the first check pad 601. The second check pad 701 is also provided further inward in the longitudinal direction of the substrate 502 than the first check pad 601. When inspecting the optical print head 105, the second check pad 701 can be used even if the first check pad 601 cannot be used. This makes it possible to make final adjustments to the amount of light, etc., while minimizing bending of the substrate 502.

[0086] When inspecting optical print head 105 before assembly into an image forming apparatus, substrate 502 is sucked by suction pads 602 at multiple locations along the length of substrate 502, as shown in Fig. 1(d). Then, a contact probe (not shown) electrically connected to a tool is brought into contact with second check pad 701 provided on substrate 502.

[0087] To maintain this contact state, a pressing force F of the probe acts on the substrate 502. In this embodiment, as shown in Figure 1(a), the second check pad 701 is placed in the center in the longitudinal direction of the substrate 502. Therefore, the pressing force F of the probe (Figure 1(d)) is generated in the center in the longitudinal direction of the substrate 502 where the second check pad 701 is placed.

[0088] However, when inspecting the optical print head 105, unlike when adjusting it, the substrate 502 is adhesively fixed to the holder 54 and further sealed. Therefore, even if the second check pad 701 is positioned on the front and back surfaces of the substrate 502 so as to overlap the area where the LED chip 639 of the substrate 502 is mounted, the effect of bending on the entire optical print head 105 can be suppressed.

[0089] Furthermore, the first check pad 601 and second check pad 701 described above both have the function of emitting light from the LED chip 639. In other words, check pads with the same function are provided at different positions on the substrate 502.

[0090] (Check pad after applying the sealant) Here, the first check pad 601 after applying the sealant 59 is shown in Fig. 9(a). The distance L1 shown in Fig. 9(a) is the lateral distance between the first check pad 601 and the sealant 59 after applying the sealant 59. Here, at least some of the plurality of first check pads 601 are arranged side by side in the lateral direction of the substrate 502. Therefore, by applying the sealant 59 to the four sides of the substrate 502, the sealant 59 may get close to the first check pad 601, and the distance L1 may become narrow. In Fig. 9(a), the distance L1 is clearly shown, but during manufacturing, due to variations in the application of the sealant 59, variations in component dimensions, variations in positions, etc., for example, one of the plurality of first check pads 601 may be buried in the sealant 59, and there may be no distance L1. As a result, after applying the sealant 59, the first check pad 601 may become unusable.

[0091] On the other hand, the second check pad 701 after applying the sealant 59 is shown in Fig. 9(b). The distance L2 shown in Fig. 9(b) is the lateral distance between the second check pad 701 and the sealant 59 after applying the sealant 59. Here, all of the plurality of second check pads 701 are arranged side by side in the longitudinal direction of the substrate 502. That is, the plurality of second check pads 701 are arranged in a row in the longitudinal direction. Thereby, the relationship between the distance L1 and the distance L2 is L1 < L2. By taking a larger distance from the sealant 59 compared to the first check pad 601, the second check pad 701 enables the light emission and adjustment actions of the LED chip 639 by the check pad even after applying the sealant 59.

[0092] 1(d), if the second check pad 701 is provided in the center of the substrate 502, the pressing force F from the contact probe (not shown) serving as a contact terminal connected to the adjustment tool described above will also be applied to the center of the substrate 502. However, after the substrate 502 and the lens array 506 are adhesively fixed, the rigidity of the substrate 502 and the entire optical print head 105 is high, and even if the pressing force F from the contact probe (not shown) is applied to the center of the substrate 502, the impact of partial bending of the substrate 502 and bending of the entire optical print head 105 will be minor. Therefore, the second check pad 701 can be positioned more inward than the first check pad 601. Furthermore, the second check pad 701 can be positioned so as to overlap the area of ​​the substrate 502 where the LED chip 639 is mounted.

[0093] According to this embodiment, by providing multiple check pads with the same function, it is possible to use the check pads in the most appropriate locations for each manufacturing process. Specifically, the first check pad 601 can be used in the adjustment process before bonding with adhesive, and the second check pad 701 can be used in the inspection process after sealing with sealant. This makes it possible to perform adjustments and inspections using the contact points (check pads) while minimizing the effects of bending of the portion of the substrate where the LED chip is mounted, whether before bonding the substrate with adhesive or after applying sealant to the substrate.

[0094] In the above-described embodiment, the positions and numbers of the first check pads 601 and second check pads 701 are exemplified, but the present invention is not limited to this. In the present invention, it is sufficient to have a configuration with multiple check pads having the same function.

[0095] In the above-described embodiment, the first check pad 601 is disposed at one end of the substrate 502 in the longitudinal direction, but the present invention is not limited to this. The first check pad 601 may be disposed at both ends of the substrate in the longitudinal direction.

[0096] In the above-described embodiment, two first check pads 601 and one first check pad 701 are arranged in the short side direction of the substrate 502, but the present invention is not limited to this. Any configuration may be used as long as at least one first check pad 601 is arranged in the short side direction of the substrate, and changes can be made depending on the size of the edge region and substrate 502, and the distance from the sealant 59.

[0097] In addition, in the above-described embodiment, a configuration including an FFC connector 504 to which a cable is removably connected has been illustrated, but the present invention is not limited to this. For example, the above-described first check pad 601 may be provided as a substitute for the connector 504. In this case, too, the first check pad 601 may be arranged in a position that does not overlap the mounting area of ​​the LED chip 639 on the substrate 502.

[0098] In the above-described embodiment, the first check pad 601 and the second check pad 701 are electrically connected to the light-emitting element via a connector, but this is not limiting. The check pads may have other configurations as long as they are electrically connected to the light-emitting element.

[0099] In the above-described embodiment, the first check pad 601 and the second check pad 701 are exemplified as having a circular shape, but this is not limiting. The contact points (check pads) only need to be able to come into contact with the contact probes, and the contact points may have a shape such as a rectangle or oval in which the width direction of the substrate 502 is longer than the length direction of the substrate 502.

[0100] In the above embodiment, the holder 54 is made of metal, but it is not limited to this and may be made of resin or other materials. [Explanation of symbols]

[0101] 1...Image forming device 102 ...Image forming unit 103...Photosensitive drum (photoconductor) 105...Optical print head (exposure head, exposure device) 160...FFC (flexible flat cable) 500...Exposure unit 502... Substrate 503...LED (light-emitting element, light-emitting part) 504...FFC connector 505...Holding body 506...Lens array 600...IC 601...First check pad (first contact) 639...LED chip 701...Second check pad (second contact)

Claims

1. An exposure device having an elongated shape extending in an axial direction of a photosensitive member, for exposing the photosensitive member, a substrate on which a plurality of light emitting elements that emit light to expose the photosensitive member are arranged along the axial direction; a lens array that focuses the light emitted from the light-emitting element onto the photosensitive member; a holder that holds the substrate and the lens array; a first contact point electrically connected to the light emitting element and configured to input a signal for controlling light emission of the light emitting element through a contact terminal that is in detachable contact with the light emitting element; a second contact provided at a position different from the first contact in the longitudinal direction of the substrate, electrically connected to the light emitting element, and configured to input a signal for controlling light emission of the light emitting element through a contact terminal that is detachably contacted with the light emitting element; An exposure apparatus characterized by:

2. At least one of the first contact and the second contact does not overlap with the light emitting element in the longitudinal direction of the substrate.

2. An exposure apparatus according to claim 1.

3. The first contacts include a plurality of contacts, and at least some of the plurality of first contacts are arranged side by side in a lateral direction perpendicular to a longitudinal direction of the substrate.

2. An exposure apparatus according to claim 1.

4. the second contacts include a plurality of contacts, and all of the plurality of second contacts are arranged in parallel in the longitudinal direction of the substrate; 2. An exposure apparatus according to claim 1.

5. the second contact has a contact shape that is larger in a lateral direction perpendicular to the longitudinal direction of the substrate than in a longitudinal direction of the substrate; 2. An exposure apparatus according to claim 1.

6. the first contact is disposed at one end of the substrate in a longitudinal direction; the second contact is disposed more inward than the first contact in the longitudinal direction of the substrate; 2. An exposure apparatus according to claim 1.

7. a connector electrically connected to the light emitting element and to which a cable is removably connected; The first contact is disposed closer to an end of the board than the connector in the longitudinal direction of the board.

2. An exposure apparatus according to claim 1.

8. the substrate has a plurality of wirings for supplying signals to the light-emitting elements; The first contact and the second contact each include a contact connected to a wiring that supplies a control signal that controls light emission of the light-emitting element, and a contact connected to a wiring that supplies power that controls light emission of the light-emitting element.

2. An exposure apparatus according to claim 1.

9. the first contact and the second contact are provided on a surface of the substrate opposite to a surface on which the light emitting element is mounted; 2. An exposure apparatus according to claim 1.

10. The light-emitting element is an organic electroluminescent element.

2. An exposure apparatus according to claim 1.

11. An exposure device comprising: a photoreceptor; and an exposure device according to any one of claims 1 to 10. An image forming apparatus characterized by:

Images