Image forming apparatus

Abstract

To improve workability in replacing an exposure head.SOLUTION: An image forming apparatus comprises: a photoreceptor; an exposure head that has a connector, has a shape longer in an axial direction of the photoreceptor, and exposes the photoreceptor; a cable that electrically connects a control board and the connector; and a guide member that is provided extending in a short direction orthogonal to a longitudinal direction of the exposure head, and supports the cable along the short direction. The guide member has a storage part storing a bent part of the cable that is an extra length part longer than the distance between the control board and the connector and is bent in the short direction, and a first opening through which the cable stored in the storage part penetrates toward the exposure head. The first opening is arranged overlapping the connector in the longitudinal direction of the exposure head, and is arranged not overlapping the storage part in the short direction of the exposure head.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus that exposes a photoconductor with an exposure head. [Background technology]

[0002] In electrophotographic image forming devices, an LED exposure head is one of the exposure devices that exposes the photoconductor. An LED exposure head is a device that exposes the image width all at once by arranging a certain number of LEDs in a roughly linear manner. This is advantageous for miniaturizing the device and reducing noise because it is smaller in volume and has no drive unit compared to laser scanner units that use polygon mirrors.

[0003] As a means for operating the LED exposure head, a technique is known in which a signal is sent from a control unit of the image forming apparatus to the LED exposure head via a flexible flat cable (hereinafter abbreviated as FFC).

[0004] Patent Document 1 describes a method for removing an LED exposure head connected to an FFC from inside an image forming apparatus. First, an operator pulls out the LED exposure head slightly toward the front of the image forming apparatus. After that, the operator accesses the inside of the image forming apparatus from the side and removes the FFC from the LED exposure head. After that, the operator returns to the front of the image forming apparatus and pulls out the LED exposure head toward the front of the image forming apparatus. In this way, the LED exposure head is removed from inside the image forming apparatus. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2015-205497 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the configuration of Patent Document 1 provides an excess length of the FFC in the longitudinal direction of the exposure head. In order to simplify the replacement work of the LED exposure head, it is necessary to increase the excess length of the FFC. However, in the configuration of Patent Document 1, if the excess length of the FFC is increased, the excess length of the FFC will occupy a large amount of space below the LED exposure head. Because a moving mechanism for moving the LED exposure head in the optical axis direction, a duct for cooling the LED exposure head, and the like are arranged below the LED exposure head, it is not possible to ensure a large space. Therefore, it is not possible to provide a large excess length of the FFC, and as a result, the configuration makes it difficult to replace the LED exposure head.

[0007] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to improve the ease of replacing an exposure head. [Means for solving the problem]

[0008] A typical configuration of the present invention for achieving the above-mentioned object includes a photosensitive body, an exposure head having a connector and elongated in the axial direction of the photosensitive body, exposing the photosensitive body, a cable electrically connecting a control board and the connector, and a guide member extending in a short direction perpendicular to the longitudinal direction of the exposure head and supporting the cable along the short direction, wherein the guide member has a storage section that stores a bent portion of the cable bent in the short direction by an excess length that is longer than the distance between the control board and the connector, and a first opening through which the cable stored in the storage section passes toward the exposure head, and the first opening is positioned so as to overlap with the connector in the longitudinal direction of the exposure head, and is positioned so as not to overlap with the storage section in the short direction of the exposure head. Effect of the Invention

[0009] According to the present invention, the workability of replacing the exposure head is improved. [Brief description of the drawings]

[0010] [Figure 1]1A and 1B are diagrams showing the arrangement of an exposure head and a guide member according to a first embodiment; [Diagram 2] FIG. 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus. [Diagram 3] FIG. 1 is a perspective view of an image forming apparatus; [Figure 4] 1A and 1B are perspective views showing the configuration of the drum unit and the developing unit and its surroundings. [Diagram 5] Schematic perspective view of an exposure unit [Figure 6] (a), (b), and (c) are diagrams showing a substrate in an optical print head, and (d) and (e) are diagrams showing a lens array. [Figure 7] FIG. 1 is a perspective view showing the arrangement of an FFC according to a first embodiment; [Figure 8] Cross-sectional view showing the arrangement of the FFC according to the first embodiment. [Figure 9] An enlarged cross-sectional view of the vicinity of the frontage in FIG. [Figure 10] FIG. 1 is a cross-sectional view showing the arrangement of an FFC when the moving mechanism according to the first embodiment is in operation; [Figure 11] FIG. 1 is a perspective view showing an operation of removing an exposure head according to a first embodiment; [Figure 12] FIG. 1 is a cross-sectional view showing a state of an FFC when an exposure head according to a first embodiment is taken out. [Figure 13] FIG. 1 is a cross-sectional view showing a state of an FFC when an exposure head according to a first embodiment is attached. [Figure 14] FIG. 1 is a cross-sectional view showing the FFC storage operation after replacing the exposure head according to the first embodiment; [Figure 15] FIG. 11 is a perspective view showing the arrangement of the FFC according to the second embodiment; [Figure 16] Cross-sectional view showing the arrangement of the FFC according to Example 2. [Figure 17] FIG. 11 is a cross-sectional view showing the state of the FFC when the exposure head according to the second embodiment is removed. [Figure 18] FIG. 11 is a cross-sectional view showing the state of the FFC when the exposure head according to the second embodiment is attached. [Figure 19] FIG. 11 is a cross-sectional view showing the FFC storage operation after replacing the exposure head according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. However, the components described in this description are merely examples, and the present invention is not limited to the embodiments described in this description.

[0012] Example 1 (Image forming device) First, a schematic configuration of the image forming apparatus 1 will be described. FIG. 2 is a cross-sectional view showing a schematic configuration of the image forming apparatus 1. FIG. 3 is an external perspective view of the image forming apparatus 1. The image forming apparatus 1 shown in FIG. 2 and FIG. 3 illustrates an image forming apparatus equipped with a reading device 2, but the image forming apparatus may not be equipped with a reading device. Furthermore, the embodiment is not limited to a so-called tandem type color image forming apparatus equipped with a plurality of photosensitive drums 103 as shown in FIG. 2, but may be a color image forming apparatus equipped with one photosensitive drum 103 or an image forming apparatus that forms a monochrome image.

[0013] The image forming apparatus 1 shown in Fig. 2 includes four image forming units 102Y, 102M, 102C, and 102K (hereinafter collectively referred to simply as "image forming unit 102") that form toner images of the respective colors of yellow, magenta, cyan, and black. The image forming units 102Y, 102M, 102C, and 102K include photosensitive drums 103Y, 103M, 103C, and 103K (hereinafter collectively referred to simply as "photosensitive drum 103") as photosensitive bodies (image carriers). These photosensitive drums are arranged at a distance from each other. The image forming units 102Y, 102M, 102C, and 102K are equipped with chargers 104Y, 104M, 104C, and 104K (hereinafter collectively referred to as "charger 104") as charging means for charging the photosensitive drums 103Y, 103M, 103C, and 103K, respectively. The image forming units 102Y, 102M, 102C, and 102K are equipped with LED (Light Emitting Diode, hereinafter referred to as LED) exposure units 500Y, 500M, 500C, and 500K (hereinafter collectively referred to as "exposure unit 500") as exposure light sources for emitting light for exposing the photosensitive drums 103Y, 103M, 103C, and 103K. Furthermore, the image forming units 102Y, 102M, 102C, and 102K each include 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 a toner image of each color on the photosensitive drum 103. The letters Y, M, C, and K attached to the reference characters indicate the colors of the toner.

[0014] The image forming apparatus 1 shown in Fig. 2 is a so-called "bottom exposure type" image forming apparatus in which the photosensitive drum 103 is exposed from below. The following description will be given on the premise that the image forming apparatus employs the bottom exposure type. Note that, although not shown in the drawings, the embodiment may also be an image forming apparatus that employs an "top exposure type" in which the photosensitive drum is exposed from above.

[0015] 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) which 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 which 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 which fixes the secondarily transferred image onto the recording material S.

[0016] After the primary transfer, toner remains on the surfaces of the photosensitive drums 103Y, 103M, 103C, and 103K. The remaining 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 a collected toner container 5.

[0017] After the secondary transfer, toner remains on the surface of the intermediate transfer belt 107. This residual toner is removed by a belt cleaning device (second cleaning device) 7 and collected in a collected toner container 5.

[0018] (Image formation process) Next, the image forming process of the image forming apparatus will be briefly described. 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. As a result, an electrostatic latent image is formed 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. The magenta, cyan, and black toner images are also transferred onto the intermediate transfer belt 107 in a similar image forming process.

[0019] The toner images of each color transferred onto the intermediate transfer belt 107 are transported to a secondary transfer portion T2 by the intermediate transfer belt 107. A transfer bias is applied to a secondary transfer roller 109 disposed at the secondary transfer portion T2 to transfer the toner images onto a recording material S. The toner images transported to the secondary transfer portion T2 are transferred onto the recording material S transported from a paper feed portion (paper feed cassette) 101 by the transfer bias of the secondary transfer roller 109.

[0020] 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 feed method is as follows: first, the leading edge of the recording material S is flipped up by the friction of the paper feed roller 80, and only one sheet of the recording material S is conveyed to the conveying path 20 by a pair of paper separating conveying rollers 9a, 9b for preventing double feeding of the recording material S. Thereafter, the recording material S is 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. Incidentally, the pair of registration rollers 11a, 11b perform skew correction and timing correction, and then conveys the recording material to the secondary transfer unit T2.

[0021] The recording material S onto which the toner image has been transferred at the secondary transfer portion T2 is conveyed to the fixing device 100. The fixing device 100 fixes the toner image onto the recording material S by heat and pressure. The recording material S which has been subjected to the fixing process by the fixing device 100 is discharged to a paper discharge portion 111.

[0022] As shown in FIG. 2, the image forming apparatus 1 includes toner containers 4Y, 4M, 4C, and 4K (hereinafter, collectively referred to simply as "toner containers 4"). When an image is formed, the amount of toner in a developing unit 641 (described later) decreases. At that time, the toner is supplied to the developing unit 641 (described later) from the toner containers 4Y, 4M, 4C, and 4K provided corresponding to the image forming sections 102Y, 102M, 102C, and 102K through pipes (not shown). That is, in the developing unit 641 (described later) provided in the image forming apparatus 1 described in this embodiment, new toner is replenished from the toner container 4, while a part of the excess toner is transported to the collected toner container 5 as residual toner.

[0023] (Drum unit and developing unit) A drum unit 518, which is an example of a replaceable unit, is attached to the image forming apparatus 1 of this embodiment. The drum unit 518 is a cartridge that is replaced by an operator such as a user or a maintenance technician. The drum unit 518 (Y, M, C, K) of this embodiment includes photosensitive drums 103 (Y, M, C, K) rotatably supported on a frame of the drum unit 518.

[0024] In addition, the image forming apparatus 1 of this embodiment is provided with a developing unit 641 separate from the drum unit 518. The developing unit 641 of this embodiment is a cartridge in which the developing device 106 and the toner storage unit shown in FIG. 2 are integrated. The developing device 106 is provided with a developing sleeve, which is a developer carrier that carries a developer. The developing unit 641 is provided with a plurality of gears for rotating a screw for stirring the toner and carrier. When these gears deteriorate over time, an operator removes the developing unit 641 from the main body of the image forming apparatus 1 and replaces it. In addition, a certain amount of toner is removed from the developing unit 641 as residual toner and transported to the collected toner container 5. The embodiment of the drum unit 518 and the developing unit 641 may be a process cartridge in which the drum unit 518 and the developing unit 641 are integrated.

[0025] As shown in FIG. 4(a), the image forming apparatus 1 includes a front plate 642 made of sheet metal and a rear plate 643 made of sheet metal. The front plate 642 is a side wall provided on the front side of the image forming apparatus 1. The front plate 642 forms a part of the housing (frame) of the main body of the image forming apparatus 1 at the front side of the main body of the image forming apparatus 1. The rear plate 643 is a side wall provided on the rear side of the image forming apparatus 1. The rear plate 643 forms a part of the housing (frame) of the main body of the image forming apparatus 1 at the rear side of the main body of the image forming apparatus 1. As shown in FIG. 4(a), the front plate 642 and the rear plate 643 are disposed facing each other, and a metal beam (not shown) is provided between them. The front plate 642, the rear plate 643, and the beam (not shown) each form a part of the frame of the image forming apparatus 1. Here, with respect to the image forming apparatus 1 of this embodiment or its constituent members, the front side or near side is the side where the drum unit 518 is inserted into and removed from the apparatus main body.

[0026] An opening 644 is formed in front side plate 642 so that drum unit 518 and developing unit 641 can be inserted and removed from the front side of image forming apparatus 1. Drum unit 518 and developing unit 641 are mounted in a predetermined position (mounting position) of the main body of image forming apparatus 1 through opening 644.

[0027] In the following description, the front plate 642 side is defined as the front side (near side or front side) and the rear plate 643 side is defined as the rear side (rear side or back side) with respect to the device body. In addition, when the photosensitive drum 103K on which the electrostatic latent image of the black toner image is formed is taken as a reference, the side on which the photosensitive drum 103Y on which the electrostatic latent image of the yellow toner image is formed is defined as the left side. When the photosensitive drum 103Y on which the electrostatic latent image of the yellow toner image is formed is taken as a reference, the side on which the photosensitive drum 103K on which the electrostatic latent image of the black toner image is formed is defined as the right side. Furthermore, the direction perpendicular to the front-rear direction and the left-right direction defined here and vertically upward is defined as the up direction, and the direction perpendicular to the front-rear direction and the left-right direction defined here and vertically downward is defined as the down direction. The defined front direction F, rear direction B, left direction L, right direction R, up direction U, and down direction D are shown in FIG. 3, FIG. 4(a), and FIG. 4(b).

[0028] The rotation axis direction of the photosensitive drum 103 described in the following text is the same as the front-rear direction shown in FIG. 4(a) and FIG. 4(b). The longitudinal direction of the exposure head 105 is also the same as the front-rear direction shown in FIG. 4(a) and FIG. 4(b). That is, the rotation axis direction of the photosensitive drum 103 and the longitudinal direction of the exposure head 105 are the same as each other. One end side in the rotation axis direction of the photosensitive drum 103 means the front side as defined here, and the other end side means the rear side as defined here. One end side and the other end side in the front-rear direction also correspond to the front side and the rear side as defined here. One end side in the left-right direction means the left side as defined here, and the other end side means the right side as defined here. The longitudinal direction of the exposure head 105 described in the following text means the front-rear direction as defined here, and the short side direction of the exposure head 105 means the left-right direction as defined here.

[0029] (Exposure unit) Next, a description will be given of the exposure unit 500 including the exposure head 105. The exposure unit 500 shown in Fig. 2 includes the exposure head 105 (see Fig. 5) that exposes the photosensitive drum 103.

[0030] Although not shown, the image forming apparatus 1 according to this embodiment includes a movement mechanism that moves the exposure head 105 to an exposure position or a retracted position (separated position) relative to the photosensitive drum 103. The movement mechanism is provided in the image forming apparatus 1, and engages with both sides of the exposure head 105 in the longitudinal direction to move the exposure head 105 to the exposure position or to a retracted position retracted from the exposure position.

[0031] (Exposure head configuration) Next, the exposure head (optical print head) 105 provided in the exposure unit 500 will be described. Here, as an example of an exposure method adopted in an electrophotographic image forming apparatus, there 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 a photosensitive drum is exposed via an f-θ lens or the like. The "exposure head 105" described in this embodiment is used for an LED exposure method in which the photosensitive drum 103 is exposed to light using light emitting elements such as LEDs arranged along the rotation axis direction of the photosensitive drum 103, and is not used for the laser beam scanning exposure method mentioned above.

[0032] The exposure head 105 described in this embodiment is provided vertically below the rotation axis of the photosensitive drum 103, and an LED 503 included in the exposure head 105 exposes the photosensitive drum 103 from below. Fig. 5 is a schematic perspective view of the exposure head 105 included in the image forming apparatus 1 of this embodiment.

[0033] The exposure head 105 has an elongated shape (longitudinal shape) extending in the direction of the rotation axis of the photosensitive drum 103. The exposure head 105 also includes a holding member 505, a lens array 506, and a substrate 502 (see FIG. 6(a)).

[0034] The holding member 505 holds the substrate 502 and the lens array 506. The holding member 505 has an opening 701 as a lens attachment portion for attaching the lens array 506. The holding member 505 is made of metal. For example, the holding member 505 is formed into a U-shape by pressing a metal plate such as a thin iron plate.

[0035] Furthermore, the holding member 505 is provided with front pins 507 and rear pins 508 at both ends in the front-rear direction of the exposure head 105. When the exposure head 105 is moved to the exposure position, the front pins 507 and rear pins 508 provided at both ends in the front-rear direction each come into contact with a predetermined location of a drum unit 518 that supports the photosensitive drum 103. This keeps the distance between the exposure head 105 and the surface of the photosensitive drum 103 constant at the exposure position.

[0036] Next, the substrate 502 will be described. Fig. 6(a) is a schematic perspective view of the substrate 502 in the exposure head 105. Fig. 6(b) is a diagram showing an arrangement of a plurality of LEDs 503 provided on the substrate 502, and Fig. 6(c) is an enlarged view of Fig. 6(b).

[0037] An LED chip 639 is mounted on the substrate 502. As shown in Fig. 6(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. The substrate 502 is provided with wiring for supplying signals to each LED chip 639. One end of a flexible flat cable (hereinafter abbreviated as FFC) 160 (see Fig. 12), which is an example of a cable, is connected to the FFC connector 504.

[0038] The image forming apparatus 1 is provided with a control board 162 (see FIG. 12) that includes a control unit and a connector. The other end of the FFC 160 is connected to the connector. That is, the FFC 160 electrically connects the control board 162 that includes the control unit and the board 502. A control signal (drive signal) is input to the board 502 from the control unit of the image forming apparatus 1 via the FFC 160 and the FFC connector 504. The LED chip 639 is driven by the control signal input to the board 502.

[0039] The LED chip 639 mounted on the substrate 502 will be described in more detail. As shown in FIG. 6(b) and FIG. 6(c), a plurality of LED chips 639-1 to 639-29 (29 chips) each having a plurality of LEDs 503 (one 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. Since the resolution of the image forming apparatus 1 of this embodiment is 1200 dpi, the LEDs 503 are arranged in a row in the longitudinal direction of the LED chips 639-1 to 639-29 such that the center-to-center distance between adjacent LEDs 503 is 21.16 μm. Therefore, the exposure range of the exposure head 105 of this embodiment is about 314 mm. The photosensitive layer of the photosensitive drum 103 is formed with a width of 314 mm or more. Since the length of the long side of an A4 size recording paper and the length of the short side of an A3 size recording paper are 297 mm, the exposure head 105 of this embodiment has an exposure range capable of forming images on the A4 size recording paper and the A3 size recording paper.

[0040] 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. 6B, the odd-numbered LED chips 639-1, 639-3, . . . 639-29 counting from the left side are mounted in a row in the longitudinal direction of the substrate 502. Also, the even-numbered LED chips 639-2, 639-4, . . . 639-28 counting from the left side 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. 6C, in the longitudinal direction of the LED chips 639, the center-to-center distance k1 between the LEDs 503 arranged at one end of one LED chip 639 and the other end of the other LED chip 639 in different adjacent LED chips 639 can be made equal to the center-to-center distance k2 between the adjacent LEDs 503 on one LED chip 639.

[0041] In this embodiment, the light-emitting element is a semiconductor LED, which is a light-emitting diode, but it may be, for example, an OLED (Organic Light Emitting Diode). This OLED is also called an organic EL (Organic Electro-Luminescence), and is a current-driven light-emitting element. For example, the OLEDs are arranged in a line along the main scanning direction (the direction of the rotation axis of the photosensitive drum 103) on a TFT (Thin Film Transistor) substrate, and are electrically connected in parallel by power supply wiring also provided along the main scanning direction.

[0042] Next, the lens array 506 will be described. FIG. 6(d) is a schematic diagram of the lens array 506 when viewed from the photosensitive drum 103 side. FIG. 6(e) is a schematic perspective view of the lens array 506. As shown in FIG. 6(d), the lens array 506 has a plurality of lenses arranged in two rows along the arrangement direction of the plurality of LEDs 503. Each lens is arranged so 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, and this arrangement is repeated alternately. Each lens is a cylindrical glass rod lens. The material of the lens is not limited to glass, and may be plastic. The shape of the lens is not limited to cylindrical, and may be a polygonal column such as a hexagonal column.

[0043] The dotted line Z in FIG. 6(e) indicates the optical axis of the lens. The exposure head 105 can be moved in a direction (up and down) generally along the optical axis of the lens indicated by the dotted line Z by a moving mechanism (not shown). The optical axis of the lens here means a line connecting the center of the light emission surface of the lens and the focal point of the lens. The radiation light emitted from the LED 503 is incident on the lens of the lens array 506. The lens has a function of focusing the incident radiation light on the surface of the photosensitive drum 103. The attachment position of the lens array 506 with respect to the opening 701 (see FIG. 5), which is the lens attachment portion, is adjusted when assembling the exposure head 105 so that the distance between the light emitting surface of the LED 503 and the light incidence surface of the lens is approximately equal to the distance between the light emission surface of the lens and the surface of the photosensitive drum 103.

[0044] (FFC and guide material configuration) Next, the configuration and FFC path around the FFC 160 that connects the FFC connector 504 of the exposure head 105 and the control board 162 having a control unit of the image forming apparatus 1 will be described with reference to Figs. 1(a), 1(b) and 7 to 9. Fig. 1(a) is a side cross-sectional view of the exposure head and the guide member, and is a cross-sectional view taken along line AA in Fig. 8. Fig. 1(b) is a top view of the exposure head and the guide member. Fig. 7 is a perspective view showing the arrangement of the FFC and the guide member relative to the exposure head. Fig. 8 is a cross-sectional view showing the arrangement of the FFC and the guide member relative to the exposure head. Fig. 9 is an enlarged cross-sectional view of the vicinity of the opening 180a in Fig. 8.

[0045] The image forming apparatus 1 has a plurality of exposure heads 105 (Y, M, C, K). An exposure head 105 (Y, M, C, K) is provided for each image forming unit 102 (Y, M, C, K). Each exposure head 105 (Y, M, C, K) is provided facing each photosensitive drum 103 (Y, M, C, K) and exposes the photosensitive drum 103 to light. The multiple exposure heads 105 (Y, M, C, K) are arranged side by side in a short direction (left-right direction) perpendicular to the long direction (front-rear direction) of the exposure head 105.

[0046] The image forming apparatus 1 includes an FFC 160 and a guide member 180, which will be described below.

[0047] The FFC 160 is a flexible flat cable that electrically connects the FFC connector 504 of each exposure head 105 and the control board 162. The image forming apparatus 1 has a plurality of FFCs 160. Each FFC 160 (Y, M, C, K) connects the FFC connector 504 (Y, M, C, K) of each exposure head 105 (Y, M, C, K) and the control board 162. The FFCs 160 (Y, M, C, K) are arranged in a stacked manner, with the FFC 160Y of the image forming unit 102Y, the FFC 160M of the image forming unit 102M, the FFC 160C of the image forming unit C, and the FFC 160K of the image forming unit 102K.

[0048] Each of the FFCs 160 (Y, M, C, K) has a straight portion 160a extending in the short-side direction of the exposure head 105 between the control board 162 and the FFC connector 504 of each exposure head 105, and a bent portion (flexed portion) 160b bent into a U-shape in the short-side direction of the exposure head 105. The straight portions 160a of each of the FFCs 160 (Y, M, C, K) are arranged in a stacked manner and fixed to each other by double-sided tape 161 as a fixing member. That is, the double-sided tape 161 is arranged so as to overlap the straight portion 160a of the FFC 160 in the short-side direction of the exposure head 105. The fixing member is not limited to the double-sided tape 161, and may be any member capable of fixing the relative positions of the FFCs 160Y, 160M, 160C, and 160K, and may be an adhesive or the like.

[0049] The guide member 180 is provided in the image forming apparatus 1 and is a guide member that regulates the position of the FFC 160. The guide member 180 is disposed directly below the exposure head 105 and extends linearly in the left-right direction. The guide member 180 supports the FFC 160 along a short-side direction perpendicular to the long-side direction of the exposure head 105. The FFC 160 is stored inside the guide member 180 and its position is regulated.

[0050] The guide member 180 has an opening 180a and an opening 180b through which the FFC 160 passes, and a storage section 180c that stores the bent section 160b of the FFC 160. The guide member 180 has an opening 180a (Y, M, C, K), an opening 180b (Y, M, C, K), and a storage section 180c (Y, M, C, K) for each exposure head 105 (Y, M, C, K). Note that, although a configuration in which the guide member 180 has an opening 180a (Y, M, C, K) for each exposure head is illustrated here, the present invention is not limited to this, and a configuration in which only one opening is provided on the control board 162 side may also be used.

[0051] The storage section 180c is a storage section that stores the bent portion 160b obtained by bending the excess length of the FFC 160 in the short-side direction by an amount longer than the distance between the control board 162 and the FFC connector 504. The opening 180b is a first opening through which the FFC 160 stored in the storage section 180c penetrates toward the exposure head 105. The opening 180a is a second opening through which the FFC 160 penetrates in the short-side direction toward the inside of the storage section 180c. The opening 180b is provided at a position closer to the exposure head 105 than the opening 180a in the up-down direction. In other words, the opening 180a is provided at a position farther from the exposure head 105 than the opening 180b in the up-down direction.

[0052] The FFC connector 504 of the exposure head 105 is longer in the longitudinal direction than in the lateral direction of the exposure head 105. The opening 180b of the guide member 180 is longer in the longitudinal direction than in the lateral direction of the exposure head. The storage section 180c of the guide member 180 is longer in the lateral direction than in the longitudinal direction of the exposure head 105. The storage section 180c is provided elongated in the left-right direction in the guide member 180 which is elongated in the left-right direction.

[0053] The opening 180b is arranged so as to overlap the FFC connector 504 in the longitudinal direction (front-rear direction) of the exposure head 105 (see FIG. 1(a)). The storage section 180c is also arranged so as to overlap the FFC connector 504 in the longitudinal direction (front-rear direction) of the exposure head 105 (see FIG. 1(a)). Furthermore, the opening 180b is arranged so as not to overlap the storage section 180c in the lateral direction (left-right direction) of the exposure head 105 (see FIG. 1(b)). In addition, the opening 180b and the storage section 180c of the guide member 180 in each image forming section 102 are all arranged so as to be shifted in the same direction in the lateral direction of the exposure head 105. In this embodiment, the opening 180b and the storage section 180c are arranged in this order as viewed from the straight section 160a of the FFC 160.

[0054] The exposure head 105 is provided so as to be removable from one side (front side) in the longitudinal direction of the exposure head 105 relative to the image forming apparatus 1 (see FIG. 11). The FFC connector 504 and the guide member 180 of the exposure head 105 are arranged biased toward one end side (front side) in the longitudinal direction of the exposure head (see FIG. 1(a)).

[0055] The guide member 180 also includes a biasing member 181 that biases the FFC 160. The biasing member 181 is disposed so as to overlap the stacked straight portions 160a of the FFC 160 in the short-side direction of the exposure head 105. The biasing member 181 is a member that restricts the FFC 160 from moving relative to the guide member 180, and is a member such as a cable clamp. The biasing member 181 biases the stacked straight portions 160a of the FFC 160 against the guide member 180.

[0056] Also, a cover member 182 that prevents the FFC 160 from dropping downward is attached to the guide member 180. However, the cover member 182 is a member for simplifying the mold for molding the guide member 180, and the guide member 180 may be configured to have a lower surface (wall) that has the same function as the cover member 182. In the guide member 180, the cover member 182 forms the opening 180a and a part (lower surface) of the storage section 180c.

[0057] The guide member 180 also has side surfaces 180f, 180g extending in the left-right direction. The side surfaces 180f, 180g are provided on the front and rear sides, respectively, and regulate the position of the FFC 160 in the longitudinal direction of the exposure head 105. The side surfaces 180f, 180g form part (side surfaces) of the opening 180a, the opening 180b, and the storage section 180c in the guide member 180.

[0058] Here, the storage section 180c has two surfaces, an upper surface 180d and a lower surface 180e, which hold the bent portion 160b. The lower surface 180e is a first plane extending linearly along the left-right direction. The upper surface 180d is a second plane extending linearly along the left-right direction, which is provided at a position closer to the exposure head 105 than the lower surface 180e via a space for storing the FFC 160. The storage section 180c allows the excess length of the FFC 160 guided from the opening 180a into the storage section 180c to bend in the left-right direction in the space between the lower surface 180e and the upper surface 180d.

[0059] Since the bent portion 160b of the FFC 160 is formed to abut against the upper surface 180d and the lower surface 180e of the storage portion 180c, the relationship H≧2R is established between the interval H between the upper surface 180d and the lower surface 180e and the bending radius R of the bent portion 160b. If the bending radius R of the bent portion 160b is smaller, the stress applied to the FFC 160 increases. If the stress increases, the FFC 160 may be damaged when moving the FFC 160 during the replacement work of the exposure head 105 described later. Therefore, it is necessary to maintain the bending radius R of the bent portion 160b at a predetermined value or more. In general, it is considered that the bending radius R is preferably 6 times or more the outer diameter of the cable, and in the present invention, it is preferably 6 times or more the thickness t of the FFC 160. From the above, since H≧2R≧12t, it is preferable that the interval H between the upper surface 180d and the lower surface 180e is 12 times or more the thickness t of the FFC 160. In this embodiment, the lower surface 180e is formed by the cover member 182, but it may be formed by the guide member 180 as described above.

[0060] Next, the path of the FFC 160 will be described.

[0061] The FFC 160 connected to the control board 162 arranged on the left side of the main body is first laminated on the left side of the main body with FFC 160Y, FFC 160M, FFC 160C, and FFC 160K, and fixed together with double-sided tape 161 so as to be integrated. The integrated FFC 160 is bent from the left side of the main body to the right side near the opening 180a of the guide member 180, and a straight section 160a is formed. The FFC 160 penetrates the opening 180a of the guide member 180 in the region of the straight section 160a and enters the inside of the guide member 180. At this time, the FFC 160 is urged from the upper side of the main body to the lower side by the urging member 181 provided on the guide member 180 at the straight section 160a. The FFC 160 is held so as not to move in the left-right direction of the main body by the frictional force generated by being sandwiched between the urging member 181 and the guide member 180.

[0062] The FFC 160 that has entered the inside of the guide member 180 passes under the opening 180bY of the guide member 180 and enters the storage section 180cY. Here, only the FFC 160Y of the image forming unit 102Y forms a U-shaped bent section 160bY along the storage section 180cY, and is then arranged so as to face from the right side of the main body to the left side of the main body. The FFC 160Y is further folded back when it reaches the bottom side of the opening 180bY, and is arranged so as to face the FFC connector 504Y of the exposure head 105Y. The FFC 160Y is directly connected to the FFC connector 504Y of the exposure head 105Y, and electrically connects the control board 162 and the exposure head 105Y.

[0063] The FFC 160M of the image forming unit 102M, the FFC 160C of the image forming unit 102C, and the FFC 160K of the image forming unit 102K are arranged so as to branch off from the FFC 160Y in the storage unit 180cY and then head from the left side of the main body to the right side of the main body. The subsequent path passes under the opening 180b in each of the image forming units 102M, 102C, and 102K in the same manner as the image forming unit 102Y, and only the FFC of the target image forming unit is arranged so as to form a U-shape in the storage unit 180c and head from the right side of the main body to the left side of the main body. In addition, when it reaches the bottom side of the opening 180b, it turns back again and heads toward the FFC connector 504 of the exposure head 105, and electrically connects the control board 162 and the FFC connector 504.

[0064] As described above, the control board 162 and the exposure head 105 are connected by the FFC 160. Note that, in this embodiment, the FFC 160 is connected from the control board 162 provided on the left side of the main body and arranged toward the right side of the main body, but it may be arranged from the control board 162 provided on the right side of the main body toward the left side of the main body. Also, in this embodiment, the configuration is assumed to be a color image forming device and has four image forming units of YMCK, but it may also be a configuration with only one image forming unit of K. In that case, the double-sided tape 161 that relatively fixes the FFC will not be necessary.

[0065] Next, the behavior of the FFC 160 during operation of the exposure head movement mechanism (not shown) will be described with reference to Fig. 10. Fig. 10 is a cross-sectional view showing the arrangement of the FFC 160 and the guide member 180 when only the exposure head 105K of the image forming unit 102K is moved by the movement mechanism.

[0066] As described above, the exposure head 105 can be displaced in the optical axis direction (Z direction) by a moving mechanism (not shown) and transition between a position close to the photosensitive drum 103 (exposure position) and a position away from the photosensitive drum 103 (retracted position). At this time, the FFC 160 displaces in the optical axis direction while remaining connected to the exposure head 105, so the position of the FFC 160 also changes together with the exposure head 105. FIG. 8 shows the path of the FFC 160 when the exposure head 105 is in the exposure position, and FIG. 10 shows the path of the FFC 160 when the exposure head 105 is in the retracted position. As shown in FIG. 10, the FFC 160 bends in region E, and the path changes inside the guide member 180. With this configuration, an unexpected load is not applied to the FFC 160 or the exposure head 105.

[0067] (Exposure head replacement flow) The flow of replacing the exposure head 105 will be described with reference to Figures 11 to 14. The flow of replacing the exposure head 105K of the image forming unit 102K will be described as an example. Figure 11 is a perspective view of the operation of removing the exposure head 105K. Figure 12 is a cross-sectional view showing the state of the FFC 160K when the exposure head 105K is removed. Figure 13 is a cross-sectional view showing the state of the FFC 160K when a new exposure head 105K is attached. Figure 14 is a cross-sectional view showing the operation of storing the FFC 160K after replacing the exposure head 105K. The procedure for replacing the exposure head 105K is shown below.

[0068] Step 1: Open the front cover 6 and the cartridge cover 558 (Figure 11).

[0069] Step 2: Remove the drum unit 518 and the developing unit 641 from the image forming apparatus 1 (FIG. 4(b)).

[0070] Step 3: The exposure head 105 is removed from the moving mechanism 510 and pulled out towards the front (FIG. 11).

[0071] Step 4: Remove the FFC 160 from the FFC connector 504 of the exposure head 105.

[0072] Step 5: The exposure head 105 is removed from the image forming apparatus.

[0073] Step 6: Install the new exposure head 105 in the image forming apparatus in the order of steps 5, 4, and 3 (FIG. 13).

[0074] Step 7: Open the left cover 1001 (FIG. 3) provided on the left side of the image forming apparatus 1.

[0075] Step 8: Remove the biasing member 181 of the guide member 180, and pull out the straight portion 160a of the FFC 160 to the left side of the main body (FIG. 14).

[0076] Step 9: Pull out the straight portion 160a of the FFC 160 to the designated position, and then push it back to the right side of the main body (Figure 14).

[0077] Step 10: In the order of steps 2 and 1, attach the drum unit 518 and the developing unit 641, close the cartridge cover 558 and the front cover 6, and return to the original state.

[0078] In step 3, as shown in FIG. 11, the exposure head 105 is removed from the moving mechanism and pulled out to the front side of the image forming apparatus 1. Then, as shown in FIG. 12, the bent portion 160bK of the FFC 160K stored in the storage portion 180cK is pulled out, and the exposure head 105K can be pulled out to the front side by the length L. At this time, the length L of the FFC 160K pulled out is more than twice the length M of the storage portion 180c of the guide member 180. Therefore, the longer the length M of the storage portion 180c, the longer the length L of the FFC 160 pulled out can be. Therefore, by increasing the dimension of the guide member 180, the ease of removing the FFC 160 in step 4 and the ease of attaching the FFC 160 in step 6 are improved, and the workability of replacing the exposure head 105 can be improved. In addition, the guide member 180 is arranged extending in the short direction of the exposure head 105, and even if the length M is extended, the area overlapping with the exposure head 105 does not change, and the space of the moving mechanism, etc. is not affected. Therefore, the space around the exposure head 105 can be secured while improving the ease of replacing the exposure head.

[0079] In step 6, after the new exposure head 105 is installed in the image forming apparatus, the bent portion 160b of the FFC 160 is disposed outside the storage portion 180c as shown in Fig. 13. Here, when the straight portion 160a of the FFC 160 is pulled out to the left side of the main body in step 8, the bent portions 160b of all the FFCs 160, including the FFC 160 of the image forming unit 102K, are pulled out to the left side of the main body. Therefore, as shown in Fig. 14, the bent portion 160b of the FFC 160 disappears, and an excess length of the FFC 160 is provided on the left side of the main body. This operation changes the FFC 160K of the replaced image forming unit 102K from a state in which it is disposed outside the guide member 180 to a state in which it is disposed inside the guide member 180. Then, when the straight portion 160a of the FFC 160 is pushed back in step 9, all of the YMCK FFCs 160 enter the guide member 180, and the bent portions 160b of the FFC 160 are formed in each storage portion 180c as shown in FIG.

[0080] As described above, by performing the simple task of pulling out the FFC 160 from the left side of the main body and pushing it back, the excess length of the FFC 160 returns to its original stored state in the storage section 180c as the bent section 160b. This eliminates the need for a complicated storage procedure for the FFC 160, improving the ease of replacing the exposure head.

[0081] In this embodiment, the replacement flow of the exposure head 105 of the image forming unit 102K has been exemplified, but the exposure head 105 (Y, M, C) of the other image forming units 102 (Y, M, C) can also be replaced using a similar procedure. When replacing the exposure heads of multiple image forming units at the same time, the FFC storage work of multiple image forming units can be performed simultaneously by performing steps 1 to 6 for each image forming unit and then performing steps 7 to 9 together at the end. In this embodiment, the left cover 1001 is removed in step 7, but it may be removed first.

[0082] Example 2 An image forming apparatus according to Example 2 will be described. Since the schematic configuration of the image forming apparatus is the same as that of the above-described example, except for the configuration of the guide member, members having equivalent functions are given the same reference numerals and descriptions thereof will be omitted. Only the characteristic parts of Example 2 will be described below with reference to Figs. 15 to 19.

[0083] (FFC and guide material configuration) 15 and 16, a description will be given of the configuration and FFC path around the FFC 260 that connects the FFC connector 504 of the exposure head 105 and the control board 162 including the control unit of the image forming apparatus 1. Fig. 15 is a perspective view showing the arrangement of the FFC and guide members relative to the exposure head, and Fig. 16 is a cross-sectional view showing the arrangement of the FFC and guide members relative to the exposure head.

[0084] The image forming apparatus 1 includes an FFC 260 and a guide member 280, which will be described below.

[0085] The FFC 260 is a flexible flat cable that electrically connects the FFC connector 504 of each exposure head 105 and the control board 162. The image forming apparatus 1 has a plurality of FFCs 260. Each FFC 260 (Y, M, C, K) connects the FFC connector 504 (Y, M, C, K) of each exposure head 105 (Y, M, C, K) and the control board 162. The FFCs 260 (Y, M, C, K) are arranged in a stacked manner, with the FFC 260Y of the image forming unit 102Y, the FFC 260M of the image forming unit 102M, the FFC 260C of the image forming unit C, and the FFC 260K of the image forming unit 102K.

[0086] Each of the FFCs 260 (Y, M, C, K) has, between the control board 162 and the FFC connector 504 of each exposure head 105, a straight portion 260a extending in the short-side direction of the exposure head 105, and a bent portion (flexed portion) 260b bent into an S-shape in the short-side direction of the exposure head 105. In addition, the straight portions 260a of each of the FFCs 260 (Y, M, C, K) are arranged in a stacked manner, and are fixed to each other with double-sided tape 161 as a fixing member, similar to the embodiment described above.

[0087] The guide member 280 is provided in the image forming apparatus 1 and is a guide member that regulates the position of the FFC 260. The guide member 280 is disposed directly below the exposure head 105 and extends linearly in the left-right direction. The guide member 280 supports the FFC 260 along a short-side direction perpendicular to the long-side direction of the exposure head 105. The FFC 260 is stored inside the guide member 280 and its position is regulated.

[0088] The guide member 280 has an opening 280a and an opening 280b through which the FFC 260 passes, and a storage section 280c that stores the bent section 260b of the FFC 260. The guide member 280 has an opening 280a (Y, M, C, K), an opening 280b (Y, M, C, K), and a storage section 280c (Y, M, C, K) for each exposure head 105 (Y, M, C, K). Note that, although a configuration in which the guide member 280 has an opening 280a (Y, M, C, K) for each exposure head is illustrated here, the present invention is not limited to this, and a configuration in which only one opening is provided on the control board 162 side may also be used.

[0089] The storage section 280c is a storage section that stores the bent portion 260b in which the excess length of the FFC 260 that is longer than the distance between the control board 162 and the FFC connector 504 is bent in the short-side direction. The opening 280b is a first opening through which the FFC 260 stored in the storage section 280c penetrates toward the exposure head 105. The opening 280a is a second opening through which the FFC 260 penetrates in the short-side direction toward the inside of the storage section 280c. The opening 280b is provided at a position closer to the exposure head 105 than the opening 280a in the up-down direction. In other words, the opening 280a is provided at a position farther from the exposure head 105 than the opening 280b in the up-down direction.

[0090] The FFC connector 504 of the exposure head 105 is longer in the longitudinal direction than in the lateral direction of the exposure head 105. The opening 280b of the guide member 280 is longer in the longitudinal direction than in the lateral direction of the exposure head 105. The storage section 280c of the guide member 280 is longer in the lateral direction than in the longitudinal direction of the exposure head 105. The storage section 280c is provided elongated in the left-right direction in the guide member 180 that is elongated in the left-right direction.

[0091] The opening 280b is arranged so as to overlap the FFC connector 504 in the longitudinal direction (front-rear direction) of the exposure head 105. The storage section 280c is also arranged so as to overlap the FFC connector 504 in the longitudinal direction (front-rear direction) of the exposure head 105. Furthermore, the opening 280b is arranged so as not to overlap the storage section 280c in the lateral direction (left-right direction) of the exposure head 105. In addition, the opening 280b and the storage section 280c of the guide member 280 in each image forming section 102 are all arranged so as to be shifted in the same direction in the lateral direction of the exposure head 105. In this embodiment, as viewed from the straight portion 260a of the FFC 260, the storage section 280c and the opening 280b are arranged in this order.

[0092] The guide member 280 also has side surfaces 280f, 280g extending in the left-right direction. The side surfaces 280f, 280g are provided on the front and rear sides, respectively, and regulate the position of the FFC 260 in the longitudinal direction of the exposure head 105. The side surfaces 280f, 280g form part (side surfaces) of the opening 280a, the opening 280b, and the storage section 280c in the guide member 280.

[0093] Here, the storage section 280c has two surfaces, an upper surface 280d and a lower surface 280e, which hold the bent portion 260b. The lower surface 280e is a first plane extending linearly along the left-right direction. The upper surface 280d is a second plane extending linearly along the left-right direction, which is provided at a position closer to the exposure head 105 than the lower surface 280e via a space for storing the FFC 260. The storage section 280c allows the excess length of the FFC 260 guided from the opening 280a into the storage section 280c to bend in the left-right direction in the space between the lower surface 280e and the upper surface 280d.

[0094] Next, the path of the FFC 260 will be described.

[0095] The FFC 260 connected to the control board 162 arranged on the left side of the main body is first stacked on the left side of the main body with FFC260Y, FFC260M, FFC260C, and FFC260K, and fixed together so as to be integrated with double-sided tape 161. The integrated FFC 260 is bent from the left side of the main body to the right side near the opening 280a of the guide member 280, forming a straight portion 260a. The FFC 260 penetrates the opening 280a of the guide member 280 in the region of the straight portion 260a and enters the inside of the guide member 280.

[0096] The FFC 260 that has entered the inside of the guide member 280 enters the storage section 280cY before passing under the opening 280bY of the guide member 280. Here, only the FFC 260Y of the image forming unit 102Y forms an S-shaped bent section 260bY along the storage section 280cY, and is arranged so that it moves from the right side of the main body to the left side of the main body, then turns back again and moves from the left side of the main body to the right side of the main body. When the FFC 260Y reaches the bottom of the opening 280bY, it is arranged so that it moves toward the FFC connector 504Y of the exposure head 105Y. The FFC 260Y is directly connected to the FFC connector 504Y of the exposure head 105, and electrically connects the control board 162 and the exposure head 105Y.

[0097] The FFC 260M of the image forming unit 102M, the FFC 260C of the image forming unit 102C, and the FFC 260K of the image forming unit 102K are arranged so as to branch from the FFC 260Y in the storage unit 280cY and then head from the left side of the main body to the right side of the main body. After that, each FFC is arranged in each image forming unit 102M, 102C, and 102K in the same manner as the image forming unit 102Y. That is, the FFC of the target image forming unit passes under the opening 280b, forms an S-shape in the storage unit 280c, heads from the right side of the main body to the left side of the main body once, turns back again, and heads from the left side of the main body to the right side of the main body. Also, when it reaches the bottom of the opening 180b, it is arranged so as to head toward the FFC connector 504 of the exposure head 105, and electrically connects the control board 162 and the FFC connector 504.

[0098] As described above, the control board 162 and the exposure head 105 are connected by the FFC 260. Note that, although in this embodiment, the FFC 260 is connected from the control board 162 provided on the left side of the main body and arranged toward the right side of the main body, it may be arranged from the control board 162 provided on the right side of the main body toward the left side of the main body.

[0099] (Exposure head replacement flow) The flow of replacing the exposure head 105 will be described with reference to Figures 16 to 19. For the sake of explanation, an example of replacing the exposure head 105 of the K station is shown. Figure 17 is a cross-sectional view showing the state of the FFC 260 when the exposure head 105 is removed. Figure 18 is a cross-sectional view showing the state of the FFC 260 when a new exposure head 105 is installed. Figure 19 is a cross-sectional view showing the operation of storing the FFC 260 after replacing the exposure head 105. The procedure for replacing the exposure head 105 is shown below.

[0100] Steps 1 to 7: These are the same as in Example 1, and so a description thereof will be omitted here.

[0101] Step 8: Remove the biasing member 181 of the guide member 280, and pull out the straight portion 260a of the FFC 260 to the left side of the main body (FIG. 19).

[0102] Step 9: After pulling out the straight portion 260a of the FFC 260 to a predetermined position, the straight portion 260a of the FFC 260 is pushed back to a predetermined position to the right side of the main body while holding the FFC 260 near the opening 280b of the guide member 280 (FIG. 19).

[0103] Step 10: This is the same as in the first embodiment, and so a detailed explanation is omitted here.

[0104] In step 3, when the exposure head 105 is pulled out toward the front, the bent portion 260b of the FFC 260 stored in the storage portion 280c is pulled out as shown in FIG. 17, and the exposure head 105K can be pulled out toward the front by the length L. At this time, the length L by which the FFC 260K is pulled out is three times or more the length N of the storage portion 280c of the guide member 280. Therefore, the longer the length N of the storage portion 280c, the longer the length L by which the FFC 260 is pulled out can be. Therefore, by increasing the dimension of the guide member 280, the ease of removing the FFC 260 in step 4 and the ease of attaching the FFC 260 in step 6 are improved, and the workability of replacing the exposure head can be improved.

[0105] In step 6, after the new exposure head 105 is installed in the image forming apparatus, the bent portion 260b of the FFC 260 is disposed outside the storage portion 280c as shown in Fig. 18. Here, when the straight portion 260a of the FFC 260 is pulled out to the left side of the main body in step 8, the bent portions 260b of all the FFCs 260, including the FFC 260 of the image forming unit 102K, are pulled out to the left side of the main body. Therefore, as shown in Fig. 19, the bent portion 260b of the FFC 260 disappears, and an excess length of the FFC 260 is provided on the left side of the main body. This operation changes the state in which the FFC 260K of the replaced image forming unit 102K is disposed inside the guide member 280 instead of being disposed outside the guide member 280. Then, when the straight portion 260a of the FFC 260 is pushed back in step 9, all of the YMCK FFCs 260 enter the guide member 280, and the bent portions 260b of the FFC 260 are formed in each storage portion 280c as shown in FIG.

[0106] However, at this time, the worker needs to work while regulating the position of the FFC 260 near the opening 280b of the guide member 280. Also, the guide member 280 is arranged extending in the short direction of the exposure head 105, and even if the length N of the storage section 280c is extended, the area overlapping with the exposure head 105 does not change, and there is no effect on the space for the moving mechanism, etc. Therefore, it is possible to improve the workability of replacing the exposure head while ensuring space near the exposure head 105.

[0107] As described above, in the second embodiment, although it is necessary to perform the work while restricting the FFC in step 9, the extra length of the FFC can be made longer than in the first embodiment, and the workability of replacing the exposure head can be further improved. [Explanation of symbols]

[0108] 1. Image forming device 102 ... Image forming section 103 ... Photosensitive drum 105 ... exposure head 160,260 ... FFC (flexible flat cable) 160a,260a...Straight section 160b,260b...bending part 161 ... Double-sided tape (fixing material) 162 ... Control board 180,280 ... Guide member 180a, 280a ... Frontage (second opening) 180b, 280b ... opening (first opening) 180c, 280c … Storage area 180d, 280d ... Top surface (second plane) 180e, 280e ... bottom surface (first plane) 180f,180g,280f,280g…Side 181 ... Urging member 182 ...Cover member 500 ... exposure unit 502 ... Substrate 504...FFC connector 505 ... Retaining member 506 ... Lens array 518 ... Drum unit 641 ...Developing unit 642 ... Front side panel 643…Rear side plate

Claims

1. A photoconductor; an exposure head having a connector, elongated in an axial direction of the photoconductor, and configured to expose the photoconductor; a cable that electrically connects a control board and the connector; a guide member extending in a short side direction perpendicular to a longitudinal direction of the exposure head and supporting the cable along the short side direction, The guide member is a storage section for storing a bent portion of the cable, the bent portion being formed by bending the cable in the short direction by an amount longer than the distance between the control board and the connector; a first opening through which the cable stored in the storage section passes toward the exposure head, an exposure head that is provided with a storage section that stores a first opening portion and a second opening portion that stores a second opening portion, the first opening portion being disposed so as to overlap with the connector in a longitudinal direction of the exposure head and not to overlap with the storage section in a lateral direction of the exposure head;

2. 2. The image forming apparatus according to claim 1, wherein the storage section is disposed at a position overlapping with the connector in the longitudinal direction of the exposure head.

3. the connector is longer in a longitudinal direction than in a lateral direction of the exposure head, the first opening has a shape longer in a longitudinal direction than in a lateral direction of the exposure head, 2. The image forming apparatus according to claim 1, wherein the storage section has a shape longer in a lateral direction than in a longitudinal direction of the exposure head.

4. the exposure head is provided so as to be withdrawable from the image forming apparatus to one side in a longitudinal direction of the exposure head, 2. The image forming apparatus according to claim 1, wherein the connector and the guide member are arranged offset toward one end of the exposure head in the longitudinal direction.

5. 2. The image forming apparatus according to claim 1, wherein the guide member is provided at a position farther from the exposure head than the first opening, and has a second opening through which the cable passes in the short direction toward the inside of the storage section.

6. the storage section includes a first plane extending along the short side direction, and a second plane extending along the short side direction and disposed at a position closer to the exposure head than the first plane via a space for storing the cable, 2. The image forming apparatus according to claim 1, wherein the distance between the first plane and the second plane is equal to or greater than 12 times the thickness of the cable.

7. The cable has a straight portion extending in the short direction, 2. The image forming apparatus according to claim 1, further comprising a biasing member that biases the straight portion of the cable against the guide member.

8. The cable has a straight portion extending in the short direction, 2 . The image forming apparatus according to claim 1 , wherein the guide member is arranged in the short-side direction in the order of the first opening and the storage portion when viewed from the straight portion.

9. The cable has a straight portion extending in the short direction, 2 . The image forming apparatus according to claim 1 , wherein the guide member is arranged in the short-side direction in the order of the storage portion and the first opening portion when viewed from the straight portion.

10. A plurality of photoconductors; a plurality of exposure heads each having a connector and elongated in an axial direction of the photoconductor, the exposure heads exposing each of the photoconductors, the exposure heads being arranged side by side in a short side direction perpendicular to a long side direction of the exposure heads; a plurality of cables electrically connecting a control board and the connectors of each exposure head; a guide member extending in the short direction and supporting the cable along the short direction, The guide member is configured to: a storage section for storing a bent portion of the cable, the bent portion being formed by bending the cable in the short direction by an amount longer than the distance between the control board and the connector; a first opening through which the cable stored in the storage section passes toward the exposure head, an exposure head that is provided with a storage section that stores a first opening portion and a second opening portion that stores a second opening portion, the first opening portion being disposed so as to overlap with the connector in a longitudinal direction of the exposure head and not to overlap with the storage section in a lateral direction of the exposure head;

11. The plurality of cables have straight portions extending in the short direction, 11. The image forming apparatus according to claim 10, wherein the straight portions of the plurality of cables are arranged in a stacked manner, and the straight portions are fixed to one another by a fixing member.

12. The plurality of cables have straight portions extending in the short direction, 11. The image forming apparatus according to claim 10, wherein the straight portions of the plurality of cables are arranged in a stacked manner, and a biasing member is provided that biases the straight portions of the cables against the guide member.

Images