Exchange jig and image formation device

Abstract

To improve workability in exchange of a flexible flat cable.SOLUTION: An image formation device includes: a photoreceptor; an exposure head which has a connector, forms a shape elongated in an axial direction of the photoreceptor, and exposes the photoreceptor; a control board; a flexible flat cable configured to electrically connect the connector with the control board; and a guide member which is provided extending in a lateral direction of the image formation device and holds the flexible flat cable along the lateral direction. An exchange tool is used to exchange the flexible flat cable in the image formation device. The exchange tool has a sheet member forming an elongated shape. The sheet member has, at one end side in a longitudinal direction, a cable holding part which holds the flexible flat cable. A length from the cable holding part to the other end in the longitudinal direction is, through the guide member, a length such that the other end is exposed from a first through hole disposed at one side in the lateral direction, and the cable holding part is exposed from a second through hole disposed at the other side in the lateral direction.SELECTED DRAWING: Figure 48

Description

Technical Field

[0001] The present invention relates to an exchange tool used for exchanging a flexible flat cable connected to an exposure head and an image forming apparatus including an exposure head that exposes a photoreceptor.

Background Art

[0002] In electrophotographic image forming apparatuses such as laser beam printers and digital copiers, there is an LED exposure head as an example of an exposure unit that exposes a photoreceptor. The LED exposure head arranges a predetermined number of LEDs in a substantially linear manner and exposes the image width all at once. This is advantageous for downsizing and reducing noise of the apparatus because it has a smaller volume and no driving unit compared to a laser scanner unit using a polygon mirror.

[0003] The LED exposure head is disposed inside the image forming apparatus, and a flexible flat cable (hereinafter abbreviated as FFC) is connected thereto, and a signal from the control unit of the image forming apparatus is sent to the LED exposure head via the FFC.

[0004] Patent Document 1 describes a working method for removing an LED exposure head to which an FFC is connected from inside the image forming apparatus. First, the operator disconnects the FFC connecting the relay board and the control board from the relay board, and pulls out the support member that supports the LED exposure head and the relay board to the front side of the image forming apparatus. Then, the operator disconnects the FFC connecting the relay board and the LED exposure head from the LED exposure head, and removes the LED exposure head from the support member.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the configuration described in Patent Document 1, the FFC connecting the relay substrate and the LED exposure head is provided below the support member. Therefore, when replacing the FFC, it is necessary to remove the FFC from the LED exposure head, take it out from the inside of the image forming apparatus, and further place a new FFC inside the image forming apparatus and attach it to the exposure head, and this work is difficult.

[0007] Therefore, an object of the present invention is to improve the workability of replacing the FFC.

Means for Solving the Problems

[0008] A typical configuration of the present invention includes a photoreceptor, an exposure head having a connector, having a longitudinal shape in the axial direction of the photoreceptor, for exposing the photoreceptor, a control board, a flexible flat cable for electrically connecting the connector and the control board, and a guide member provided to extend in the left - right direction of the image forming apparatus orthogonal to the axial direction and the vertical direction, for holding the flexible flat cable along the left - right direction. The replacement tool is used for replacing the flexible flat cable in the image forming apparatus. The replacement tool has a sheet member having a longitudinal shape. The sheet member has a cable holding portion for holding the flexible flat cable at one end side in the longitudinal direction. The length from the cable holding portion to the other end in the longitudinal direction is such that the other end is exposed from a first through - hole arranged on one side in the left - right direction via the guide member, and the cable holding portion is exposed from a second through - hole arranged on the other side in the left - right direction.

Effects of the Invention

[0009] According to the present invention, the FFC connected to the exposure head can be easily replaced, and the workability of replacing the FFC can be improved.

Brief Description of the Drawings

[0010]

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Mode for Carrying Out the Invention

[0011] 〔Example 1〕 Hereinafter, the mode for carrying out the present invention will be described with reference to the drawings. Note that the dimensions, materials, shapes, relative arrangements, etc. of the components described below are not intended to limit the scope of the present invention only to these, unless otherwise specifically described.

[0012] (Image forming apparatus) First, the schematic configuration of the image forming apparatus 100 will be described with reference to FIGS. 1, 2, and 3. FIG. 1 is a perspective view of the image forming apparatus 100. FIGS. 2 and 3 are schematic cross-sectional views of the image forming apparatus in FIG. 1. The image forming apparatus 100 shown in FIGS. 1 to 3 is a copying machine including a reading device, but the embodiment may be other image forming apparatuses such as a printer not including a reading device. Further, the embodiment is not limited to a color image forming apparatus including a plurality of photosensitive drums 2 as shown in FIGS. 2 and 3, and may be a color image forming apparatus including one photosensitive drum 2 or an image forming apparatus for forming a monochrome image.

[0013]

[0014] The image forming apparatus 100 shown in FIGS. 2 and 3 includes four image forming units 1Y, 1M, 1C, and 1K (hereinafter, also collectively referred to simply as "image forming unit 1") for forming toner images of yellow, magenta, cyan, and black colors.The image forming units 1Y, 1M, 1C, and 1K each include a photosensitive drum 2Y, 2M, 2C, 2K (hereinafter, also collectively referred to simply as "photosensitive drum 2"), which is an example of a photoreceptor. The photosensitive drum 2 may be a photosensitive belt.

[0015] The image forming units 1Y, 1M, 1C, and 1K each include a charging roller 3Y, 3M, 3C, 3K (hereinafter, also collectively referred to simply as "charging roller 3") as charging means for charging the photosensitive drums 2Y, 2M, 2C, and 2K.

[0016] The image forming units 1Y, 1M, 1C, and 1K each include an LED (Light Emitting Diode, hereinafter referred to as LED) exposure head 4Y, 4M, 4C, 4K (hereinafter, also collectively referred to simply as "exposure head 4") as exposure means for exposing the photosensitive drums 2Y, 2M, 2C, and 2K.

[0017] Furthermore, the image forming units 1Y, 1M, 1C, and 1K each include a developing unit 24Y, 24M, 24C, 24K (hereinafter, also collectively referred to simply as "developing unit 24") as developing means for developing the electrostatic latent image on the photosensitive drum 2 with toner and forming toner images of each color on the photosensitive drum 2. Note that Y, M, C, and K attached to the reference numerals indicate the colors of the toner.

[0018] The image forming apparatus 100 shown in FIGS. 2 and 3 is an image forming apparatus that employs a so-called "bottom surface exposure method" in which the photosensitive drum 2 is exposed from below, that is, the exposure head 4 is disposed below the photosensitive drum 2. Hereinafter, the description will proceed on the premise of an image forming apparatus that employs the bottom surface exposure method. Although not shown, as an embodiment, an image forming apparatus that employs a "top surface exposure method" in which the photosensitive drum is exposed from above may also be used.

[0019] The image forming apparatus 100 includes an intermediate transfer belt 9 onto which a toner image formed on a photosensitive drum 2 is transferred, and primary transfer rollers 6 (Y, M, C, K) that sequentially transfer the toner image formed on the photosensitive drum 2 onto the intermediate transfer belt 9. The intermediate transfer belt 9 is disposed above the image forming unit 1. Note that, in addition to the intermediate transfer method using the intermediate transfer belt 9, a direct transfer method in which the image is directly transferred from the photosensitive drum 2 to the paper may be used.

[0020] Further, the image forming apparatus 100 includes a secondary transfer roller 16 as transfer means for transferring the toner image on the intermediate transfer belt 9 onto the recording paper P conveyed from the feeding unit 11, and a fixing device 19 as fixing means for fixing the secondarily transferred image onto the recording paper P.

[0021] Also, toner bottles 22Y, 22M, 22C, 22K (hereinafter, also collectively referred to simply as "toner bottle 22") for storing replenishing toner of each color are units that can be detachably replaced with respect to the image forming apparatus 100. The toner bottle 22 is disposed above the intermediate transfer belt 9. The toner bottle 22 supplies an appropriate amount of toner to each developing unit provided in the four image forming units from the corresponding toner bottle by a toner supply mechanism (not shown) at appropriate times.

[0022] The image forming apparatus 100 also includes a feeding unit 11 for feeding the recording paper P. The feeding unit 11 includes sheet cassettes 12a, 12b, feeding rollers 13a, 13b, and a registration roller 15. The sheet cassettes 12a, 12b are disposed below the image forming unit 1. The recording paper P stored in the sheet cassettes 12a, 12b is fed one by one by the feeding rollers 13a, 13b and conveyed to the secondary transfer unit T2 at a predetermined timing by the registration roller 15.

[0023] (Image forming process) Next, the image forming process of the above image forming apparatus 100 will be briefly described. The charging roller 3Y charges the surface of the photosensitive drum 2Y. The exposure head 4Y exposes the surface of the photosensitive drum 2Y charged by the charging roller 3Y. Thereby, an electrostatic latent image is formed on the photosensitive drum 2Y. Next, the developing unit 24Y develops the electrostatic latent image formed on the photosensitive drum 2Y with yellow toner. The yellow toner image developed on the surface of the photosensitive drum 2Y is transferred onto the intermediate transfer belt 9 by the primary transfer roller 6Y. The magenta, cyan, and black toner images are also formed by the same image forming process and transferred so as to be superimposed on the intermediate transfer belt 9.

[0024] The toner images of each color transferred onto the intermediate transfer belt 9 are conveyed to the secondary transfer section T2 by the intermediate transfer belt 9. The toner images conveyed to the secondary transfer section T2 are collectively transferred onto the recording paper P conveyed from the feeding section 11 by the secondary transfer roller 16. The recording paper P onto which the toner image has been transferred is conveyed to the fixing device 19. The fixing device 19 fixes the toner image onto the recording paper P by heat and pressure. The recording paper P on which the fixing process has been performed by the fixing device 19 is discharged to the discharge tray 21 disposed above the toner bottle 22 by the discharge roller 20.

[0025] (Drum Unit and Developing Unit) The replaceable drum unit 23 and developing unit 24 in the image forming apparatus 100 of this embodiment will be exemplified and described.

[0026] The above-described photosensitive drum 2 and charging roller 3 are unitized (drum unit, drum cartridge) together with a cleaning device (not shown). An example of its configuration will be described with reference to FIGS. 4, 5, 6, and 7. FIGS. 4 and 5 are perspective views showing the schematic structures around the drum units 23 (Y, M, C, K) and the developing units 24 (Y, M, C, K) provided in the image forming apparatus 100. FIG. 6 is a view showing the state in which the drum unit 23 is inserted into and removed from the image forming apparatus 100 from the outside of the apparatus main body. FIG. 7 is a view showing the state in which the developing unit 24 is inserted into and removed from the image forming apparatus 100 from the outside of the apparatus main body.

[0027] The image forming apparatus 100 is attached with drum units 23Y, 23M, 23C, 23K (hereinafter, also simply referred to as "drum unit 23" in general) each including a photosensitive drum 2. The drum unit 23 is a cartridge that is replaced by an operator such as a user or a maintenance person. The drum unit 23 rotatably supports the photosensitive drum 2. Specifically, the photosensitive drum 2 is rotatably supported by the frame of the drum unit 23. Note that the drum unit 23 may be configured not to include the charging roller 3 or the cleaning device.

[0028] In addition, the image forming apparatus 100 is attached with developing units 24Y, 24M, 24C, 24K (hereinafter, also simply referred to as "developing unit 24" in general), which are separate from the drum unit 23 that is a photoreceptor unit. The developing unit 24 includes developing sleeves 5Y, 5M, 5C, 5K (hereinafter, also simply referred to as "developing sleeve 5" in general) as developer carriers for carrying a developer, and screws 7Y, 7M, 7C, 7K (hereinafter, also simply referred to as "screw 7" in general) for supplying the developer to the developing sleeve 5 and stirring the developer. The developing unit 24 is a cartridge in which the developing sleeve 5 and the screw 7 are integrated, and is removed from and replaced with the apparatus main body of the image forming apparatus 100 by an operator as shown in FIGS. 5 and 7.

[0029] Here, inside the developing unit 24, the toner is circulated and conveyed at high speed by the screw 7. The rotation speed of the screw 7 is relatively very high with respect to the rotation speeds of the developing sleeve 5 and the photosensitive drum 2, enabling uniform coating on the developing sleeve 5 without unevenness.

[0030] Further, the image forming apparatus 100 includes cartridge trays 30 (30Y, 30M, 30C, 30K) for each image forming section (see FIGS. 8 and 9). The drum unit 23 and the developing unit 24 are supported by the cartridge trays 30 for each image forming section, guided in the axial direction of the photosensitive drum, and inserted into and removed from the apparatus main body of the image forming apparatus 100.

[0031] Also, the image forming apparatus 100 includes a front plate 100F formed of sheet metal and a rear plate 100B also formed of sheet metal (see FIG. 22). The front plate 100F is a side wall provided on the front side of the image forming apparatus 100. The front plate 100F forms a part of the housing of the apparatus main body on the front side of the image forming apparatus 100. The rear plate 100B is a side wall provided on the rear side of the image forming apparatus 100. The rear plate 100B forms a part of the housing of the apparatus main body on the back side of the image forming apparatus 100. The front plate 100F and the rear plate 100B are arranged facing each other on one side and the other side in the axial direction of the photosensitive drum, and a sheet metal (not shown) as a beam is bridged between them. The front plate 100F, the rear plate 100B, and the beam (not shown) each constitute a part of the frame (housing) of the image forming apparatus. Here, with respect to the image forming apparatus or its constituent members of this embodiment, the front side or the front side refers to the side where the drum unit 23 and the developing unit 24 are inserted into and removed from (inserted and removed) the apparatus main body of the image forming apparatus 100.

[0032] Note that one side of the cartridge tray 30 is attached to the front plate 100F (see FIG. 22) and the other side is attached to the rear plate 100B (see FIG. 22) in the axial direction of the photosensitive drum. The cartridge tray 30 will be described later.

[0033] Since the drum unit 23 and the developing unit 24 deteriorate due to repeated image forming processes, they are in the form of units (cartridges) that can be maintained by replacement or attachment / detachment.

[0034] Fig. 3 shows the arrangement of the drum unit 23, the developing unit 24, and the exposure head 4 when performing replacement or attachment / detachment. In the image forming apparatus shown in Fig. 3, unlike the image forming apparatus shown in Fig. 2, it can be seen that the developing unit 24 and the exposure head 4 are retracted from the photosensitive drum 2 and are separated.

[0035] This is because if the state where the developing unit 24 and the exposure head 4 are arranged close to the photosensitive drum 2 is maintained as shown in Fig. 2, there is a risk that each unit may be damaged due to dynamic interference during unit attachment / detachment, or further, the unit may become impossible to remove.

[0036] Therefore, when attaching / detaching the unit, the developing unit 24 and the exposure head 4 are retracted from the photosensitive drum 2 and separated as shown in Fig. 3 by a retraction mechanism including the developing stay 31, the rotating arm 65, the elevating duct 69, etc., which will be described later.

[0037] The drum unit 23 and the developing unit 24 are respectively inserted and removed from the front side of the image forming apparatus 100 and are mounted at predetermined positions (mounting positions) of the apparatus main body of the image forming apparatus 100.

[0038] The image forming apparatus 100 includes inner doors 102Y, 102M, 102C, 102K (hereinafter, also simply referred to as "inner door 102" in general) that cover the front sides of both the drum unit 23 and the developing unit 24 mounted at the mounting positions. As shown in Figs. 8 and 9, one end of the inner door 102 is fixed to the front side of the cartridge tray 30 by a hinge and is rotatable with respect to the cartridge tray 30 by the hinge.

[0039] The inner door 102 is a member necessary for protecting each unit and making it difficult for the photosensitive drum 2 to be exposed except during the image forming process, and is arranged at a position facing the front in the detachment direction of each color unit.

[0040] Furthermore, on the front side of the image forming apparatus 100, a front cover 101 forming the exterior of the apparatus is provided. One end of the front cover 101 is fixed to the front side of the apparatus main body of the image forming apparatus 100 by a hinge, and it can be rotated with respect to the apparatus main body of the image forming apparatus 100 by the hinge. The front cover 101 is provided on the front side of the inner door 102 in the axial direction of the photosensitive drum. In the closed state shown in FIG. 1, the front cover 101 covers the entire plurality of inner doors 102 arranged in the left - right direction and forms the exterior on the front side of the apparatus.

[0041] Therefore, the replacement work of the drum unit 23 and the developing unit 24 is carried out by an operator according to the following procedure. As shown in FIG. 4, the operator opens the front cover 101, and then as shown in FIG. 5, opens the inner door 102 and takes out the drum unit 23 (FIG. 6) or the developing unit 24 (FIG. 7) inside the apparatus main body. Then, a new drum unit 23 or developing unit 24 is inserted, the inner door 102 is closed, and further the front cover 101 is closed, thereby completing the replacement work.

[0042] Note that the retracting mechanism of the developing unit 24 and the exposure head 4 is interlocked with the operation of opening this inner door 102, and retracts the developing unit 24 and the exposure head 4 from the photosensitive drum 2. This retracting mechanism (developing stay 31, rotating arm 65, elevating duct) will be described later.

[0043] Here, in the following description, the front plate side of the apparatus main body is defined as the front side (the near side or the front side), and the rear plate side is defined as the rear side (the far side or the back side). Also, when taking the photosensitive drum 2K on which an electrostatic latent image regarding the black toner image is formed as a reference, the side on which the photosensitive drum 2Y on which an electrostatic latent image regarding the yellow toner image is formed is arranged is defined as the left side. When taking the photosensitive drum 2Y on which an electrostatic latent image regarding the yellow toner image is formed as a reference, the side on which the photosensitive drum 2K on which an electrostatic latent image regarding the black toner image is formed is arranged is defined as the right side. Further, the direction perpendicular to the front-rear direction and the left-right direction defined here and vertically upward is defined as the upward direction, and the direction perpendicular to the front-rear direction and the left-right direction defined here and vertically downward is defined as the downward direction. The defined front direction F, rear direction B, right direction R, left direction L, upward direction U, and downward direction D are shown in FIG. 1.

[0044] Also, the axial direction of the photosensitive drum 2 described in the following description is the direction that coincides with the front-rear direction (the near-far direction) shown in FIG. 1. Also, the longitudinal direction of the exposure head 4 also coincides with the front-rear direction shown in FIG. 1. That is, the axial direction of the photosensitive drum 2 and the longitudinal direction of the exposure head 4 are the same direction. Also, one end side in the axial direction of the photosensitive drum 2 means the front side defined here, and the other end side means the rear side defined here. The one end side and the other end side in the front-rear direction also correspond to the front side and the rear side defined here. One end side in the left-right direction means the left side defined here, and the other end side means the right side defined here.

[0045] (Exposure head) Next, the exposure head 4 will be described with reference to FIGS. 10 to 18. FIG. 10 is a schematic cross-sectional view of the exposure head 4 included in the image forming apparatus of the present embodiment. FIG. 11 is a perspective view of the exposure head 4 as seen from above. FIG. 12 is a perspective view of the exposure head 4 as seen from below.

[0046] The exposure head 4 has an elongated shape (longitudinal shape) extending in the axial direction of the photosensitive drum 2. The exposure head 4 includes a substrate 50, a light-emitting element mounted on the substrate 50, a lens array 52, and a holding member that holds the substrate 50 and the lens array 52. The holding member has a housing 54, which will be described later, and a housing support member 55 that supports the housing 54. Here, the exposure head 4 includes an LED 51 (Light Emitting Diode) as a light-emitting element that emits light.

[0047] (Substrate and lens array) Here, with reference to FIG. 13, the substrate 50 and the lens array 52 of the exposure head 4 will be described. First, the substrate 50 will be described. FIG. 13(a) is a schematic perspective view of the substrate 50. FIG. 13(b) shows the arrangement of a plurality of LEDs 51 provided on the substrate 50, and FIG. 13(c) shows an enlarged view of FIG. 13(b).

[0048] An LED chip 53 is mounted on the substrate 50. As shown in FIG. 13(a), the LED chip 53 is provided on one surface of the substrate 50, and a long FFC connector 57 is provided on the other surface. Here, one surface of the substrate 50 referred to here is the surface (upper surface, front surface) on which the LED chip 53 is provided. The other surface of the substrate 50 is the surface (lower surface, back surface) opposite to the side on which the LED chip 53 is provided.

[0049] The FFC connector 57 is attached to the other surface (lower surface, back surface) of the substrate 50 so that its longitudinal direction is along the longitudinal direction of the substrate 50. The long FFC connector 57 is provided on the front side (one side in the longitudinal direction of the substrate 50) of the image forming apparatus 100. Wiring for supplying signals to each LED chip 53 is provided on the substrate 502. One end of a flexible flat cable 58 (see FIG. 18, hereinafter FFC), which is an example of a cable, is connected to the FFC connector 57.

[0050] Note that a substrate 502 (see FIG. 28) including a control unit (not shown) and a connector 501 is provided in the control circuit unit of the image forming apparatus 100. In the present embodiment, the substrate 502 is arranged on the left side of the image forming apparatus 100, and the exposure head 4 is arranged on the right side of the substrate 502. The other ends of the FFCs 58 (58Y, 58M, 58C, 58K) connected to each exposure head 4 are connected to the respective connectors 501 (501Y, 501M, 501C, 501K) of the substrate 502 (see FIG. 28). That is, the FFC 58 electrically connects the substrate 502 and the substrate 50 of the exposure head 4. A control signal (drive signal) is input from the control circuit unit of the apparatus main body of the image forming apparatus 100 to the substrate 50 of the exposure head 4 via the FFC 58 and the FFC connector 57. The control signal is transferred to each LED chip 53. The LED chip 53 is driven (lit and extinguished) by the control signal input to the substrate 50.

[0051] As will be described later, the region between one end and the other end of the FFC 58 is held inside the image forming apparatus 100 by the FFC guide 503.

[0052] The LED chip 53 mounted on the substrate 50 will be described in more detail. As shown in FIGS. 13(b) and 13(c), on one surface of the substrate 50, LED chips 53-1 to 53-29 (29 in number), on which a plurality of LEDs 51 (an example of a light-emitting element) are arranged, are arrayed. In each of the LED chips 53-1 to 53-29, 516 LEDs 51 are arrayed in the longitudinal direction thereof. In the longitudinal direction of the LED chip 53, the center-to-center distance k2 between adjacent LEDs 51 corresponds to the recording resolution of the image forming apparatus 100. Since the recording resolution of the image forming apparatus 100 in this embodiment is 1200 dpi, in the longitudinal direction of the LED chips 53-1 to 53-29, the LEDs 51 are arrayed such that the center-to-center distance k2 between adjacent LEDs 51 is 21.16 μm. Therefore, the exposure range of the exposure head 4 in this embodiment is about 314 mm. The length of the photosensitive layer in the axial direction of the photosensitive drum 2 is formed to be 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 4 in this embodiment has an exposure range capable of forming an image on an A4-size recording paper and an A3-size recording paper.

[0053] A plurality of the LED chips 53-1 to 53-29 are arrayed in a staggered pattern in the axial direction of the photosensitive drum 2. Specifically, the LED chips 53-1 to 53-29 are alternately arranged so as to form two rows along the axial direction of the photosensitive drum 2. That is, as shown in FIG. 13(b), the odd-numbered LED chips 53-1, 53-3, ··· 53-29, counted from the left, are mounted in a row in the longitudinal direction of the substrate 50. Also, the even-numbered LED chips 53-2, 53-4, ··· 53-28, counted from the left, are mounted in a row in the longitudinal direction of the substrate 50. The LED chips 53 are arranged in this way. Thereby, as shown in FIG. 13(c), in the longitudinal direction of the LED chip 53, the center-to-center distance k1 between the LEDs 51 arranged at one end of one LED chip 53 and the other end of the other LED chip 53 in adjacent different LED chips 53 can be made equal to the center-to-center distance k2 between adjacent LEDs 51 on one LED chip 53.

[0054] In this embodiment, the light-emitting element is a semiconductor LED which is a light-emitting diode. However, for example, an OLED (Organic Light Emitting Diode) may also be used. This OLED is also called organic EL (Organic Electro-Luminescence) and is a current-driven light-emitting element. The OLEDs are arranged in a line along the main scanning direction (the axial direction of the photosensitive drum 2) on, for example, a TFT (Thin Film Transister) substrate, and are electrically connected in parallel by power supply wirings provided along the main scanning direction as well.

[0055] Next, the lens array 52 which is a lens assembly will be described. FIG. 13(d) is a schematic view when the lens array 52 is viewed from the photosensitive drum 2 side. Further, FIG. 13(e) is a schematic perspective view of the lens array 52. As shown in FIG. 13(d), the lens array 52 condenses the light emitted from the light-emitting element onto the photosensitive drum 2. The lens array 52 is a lens assembly having a plurality of lenses. These plurality of lenses are arranged in two rows along the arrangement direction of the plurality of LEDs 51. Each lens is alternately arranged such that one lens of the other row is arranged so as to be in contact with both of the adjacent lenses in the arrangement direction of the lenses in one row. Each lens is a rod lens made of cylindrical glass and has an incident surface 52b on which the light emitted from the LED 51 is incident and an emission surface 52a from which the light incident from the light incident surface is emitted (see FIG. 10). Note that the material of the lens is not limited to glass and may be made of plastic. The shape of the lens is not limited to a cylindrical shape and may be, for example, a polygonal prism such as a hexagonal prism.

[0056] The dotted line Z shown in Fig. 13(e) indicates the optical axis of the lens. The exposure head 4 is 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 retracting mechanism (the rotating arm 65 and the elevating duct 69 shown in Fig. 17) described later. Here, the optical axis of the lens means a line connecting the center of the light-emitting surface of the lens and the focal point of the lens. The lens array 52 is a lens assembly having a plurality of lenses, and the above-mentioned "optical axis" is the optical axis of any one of these plurality of lenses. Here, strictly speaking, the plurality of lenses included in the lens array 52 may be slightly inclined with respect to each other. This is due to the tolerance during assembly. However, the deviation within the tolerance range mentioned here is not considered when defining the direction of the optical axis. Therefore, it is considered that the optical axes of the plurality of lenses are all in the same direction. The lens array 52 serves to condense the light emitted from the LED 51 onto the surface of the photosensitive drum 2.

[0057] When assembling the exposure head 4, the mounting position of the lens array 52 with respect to the housing 54 is adjusted so that the distance between the light-emitting surface of the LED 51 and the light-incident surface of the lens and the distance between the light-emitting surface of the lens and the surface of the photosensitive drum 2 are substantially equal.

[0058] (Housing) As shown in Fig. 10, the housing 54 holds the lens array 52 and the substrate 50. In this embodiment, the housing 54 is a metal member formed by bending a plate material plated on a zinc-plated steel sheet or a cold-rolled steel sheet.

[0059] As described above, the housing 54 is made of metal. For example, the housing 54 is formed in a U-shape by press-working a sheet metal such as a thin iron plate. Hereinafter, the shape of the housing 54 will be described.

[0060] As shown in FIG. 10, the housing 54 has a flat portion (opposing surface) 54U in which a first opening 54a into which the lens array 52 is inserted is formed. The flat portion 54U faces the photosensitive drum 2 in the optical axis direction of the lenses of the lens array 52. Note that this flat portion 54U is not limited to a flat surface and may be a slightly curved surface. Further, the housing 54 has an extending portion 54R extending in a direction away from the photosensitive drum 2 from one side in the short side direction of the flat portion 54U. Further, the housing 54 has an extending portion 54L extending in a direction away from the photosensitive drum 2 from the other side in the short side direction of the flat portion 54U.

[0061] The extending portion 54R and the extending portion 54L form a substrate support portion for supporting the substrate 50 inserted through the second opening 54b in the housing 54. The flat portion 54U and the substrate support portion (extending portions 54R, 54L) are integrally formed, forming the housing 54 that holds the lens array 52 and the substrate 50, and its cross section is formed in a substantially U shape. By forming the housing 54 in a substantially U shape, a second opening 54b is formed on the side opposite to the flat portion 54U. The second opening 54b is formed between the substrate support portions (extending portions 54L, 54R) extending from the flat portion 54U to the side away from the photosensitive drum.

[0062] The substrate 50 is inserted through the second opening 54b, that is, from the lower side of the U-shaped housing 54, and is adhered to the inside of each substrate support portion (the inside of the extending portion 54L and the inside of the extending portion 54R) with an adhesive. Note that since the position of the substrate 50 in the focusing direction is determined by a jig (not shown), the exposure head 4 does not include a means for positioning the substrate 50 in the focusing direction.

[0063] Further, the lens array 52 is also adhered to the flat portion 54U with an adhesive in a state of being inserted into the first opening 54a formed in the flat portion 54U. Note that the lens array 52 is fixed to the flat portion 54U (housing 54) after the position and inclination in the focus direction are adjusted by a jig so that the distance in the focus direction between all the LED chips 53 mounted on the substrate 50 and the lens array 52 becomes a predetermined value. Also, the lens array 52 is fixed to the flat portion 54U with an adhesive at a plurality of locations in the longitudinal direction. That is, the exposure head 4 of the present embodiment has a plurality of adhesive portions in the longitudinal direction of the flat portion 54U for adhesively fixing the lens array 52 inserted into the first opening 54a to the flat portion 54U.

[0064] After the positions of the substrate 50 and the lens array 52 are adjusted and fixed with respect to the housing 54, the gap between the substrate 50 inserted into the second opening 54b and the housing 54 (extension portions 54L and 54R) is sealed in the longitudinal direction with a sealant 59. Thereby, it is prevented that the LED 51 is contaminated by toner or dust from the outside. Here, the sealant 59 only seals the gap (boundary portion) between the substrate 50 and the housing 54, and most of the FFC connector 57 and the substrate 50 are exposed.

[0065] Similarly, a sealing agent 59 is applied to the gap between the lens array 52 inserted into the first opening 54a and the housing 54 (flat portion 54U), and the gap is sealed longitudinally by the sealing agent 59. More specifically, as shown in FIG. 10, the sealing agent 59 seals the gap between the side wall of the lens array 52 along the longitudinal direction of the housing 54 and the edge of the first opening 54a. Thereby, it is possible to reduce the possibility that dust such as toner flows into the gap between the side wall of the lens array 52 and the first opening 54a and the light emitted from the LED 51 is blocked by the dust. Of course, the gap sealed by the sealing agent 59 seals not only the gap between one side wall of the lens array 52 and the edge of the first opening 54a but also the gap between the other side wall of the lens array 52 and the edge of the first opening 54a. The other side wall of the lens array 52 refers to the side wall opposite to one side wall of the lens array 52. Here too, the gap (boundary portion) between the housing 54 and the lens array 52 is sealed by the sealing agent 59. Thereby, it is prevented that the LED 51 is contaminated by toner or dust from the outside.

[0066] As described above, the substrate 50 and the lens array 52 are held by the housing 54, so that the LED 51 and the incident surface 52b of the lens face each other. Thereby, the light emitted from the LED 51 is incident on the incident surface 52b of the lens and is emitted from the emission surface 52a of the lens toward the photosensitive drum 2. Here, in this embodiment, the light emitted from the three LEDs 51 (a plurality of LEDs 51) can pass through the same one lens. Also, even the light emitted from one LED 51 can pass through a plurality of lenses because the light travels radially. That is, the light emitted from the plurality of LEDs 51 passes through the lens array 52 (some of the plurality of lenses included in the lens array 52) and exposes the photosensitive drum 2.

[0067] (Housing support member) As shown in FIGS. 11 and 12, the housing support member 55 supports the housing 54 holding the substrate 50 and the lens array 52 over the longitudinal direction, and is provided integrally with the housing 54. The housing support member 55 is a longitudinally shaped member extending in the axial direction of the photosensitive drum 2. The housing support member 55 is formed in a U-shape as shown in FIG. 10. The housing support member 55 has a left side wall 55L which is a first side wall, a right side wall 55R which is a second side wall facing the left side wall 55L, and a bottom face portion 55D facing the flat face portion 54U of the housing 54 between the left side wall 55L and the right side wall 55R. A plurality of openings 55a are provided in the bottom face portion 55D of the housing support member 55 in the longitudinal direction which is the axial direction of the photosensitive drum 2.

[0068] The opening 55a of the housing support member 55 is provided at a position facing the surface (the back surface of the substrate 50) opposite to the mounting surface (the front surface of the substrate 50) on which the LED 51 of the substrate 50 is mounted. The opening 55a is provided between the left side wall 55L and the right side wall 55R in the short direction orthogonal to the longitudinal direction.

[0069] The left side wall 55L which is the first side wall is provided between the housing 54 holding the substrate 50 and the developing unit 24 which is a developing means on one side in the short direction orthogonal to the axial direction of the photosensitive drum 2 as shown in FIG. 16. The left side wall 55L is provided over the axial direction of the photosensitive drum 2 so as to separate the housing 54 and the developing unit 24 as shown in FIG. 16.

[0070] The right side wall 55R which is the second side wall is provided between the housing 54 and the drum unit 23 which is an adjacent portion adjacent to the housing 54 on the other side in the short direction as shown in FIG. 16. The right side wall 55R is also provided over the axial direction of the photosensitive drum 2 so as to separate the housing 54 and the drum unit 23 in the same manner as the left side wall.

[0071] By integrally providing this housing support member 55 to the housing 54, the airflow sent from the duct unit 60 is blown onto the back surface of the substrate 50 through the opening 55a between the left side wall 55L and the right side wall 55R of the housing support member 55. Moreover, the airflow blown onto the back surface of the substrate 50 is blown in a direction orthogonal to the back surface of the substrate 50.

[0072] In this way, the airflow blown from the opening 55a of the housing support member 55 onto the back surface of the substrate 50 is separated from the developing unit 24 adjacent to the exposure head 4 by the left side wall 55L and from the drum unit 23 by the right side wall 55R. For this reason, the airflow for cooling the exposure head 4 introduced to the back surface of the substrate 50 does not leak to the side of the developing unit 24 adjacent to the exposure head 4, and it is possible to suppress the toner of the developing unit 24 from scattering inside the image forming apparatus.

[0073] Also, as described above, the housing support member 55 is provided over the longitudinal direction which is the axial direction of the photosensitive drum 2, and has an opening 55a at a position facing the back surface of the substrate 50. Thereby, the housing support member 55 of the exposure head 4 forms a duct (closed space) that blows the airflow from the duct unit 60 onto the back surface of the substrate 50 through the opening 55a and allows it to flow in the longitudinal direction of the substrate 50, that is, a part of the duct for cooling the exposure head 4.

[0074] As described above, the exposure head 4 is configured as an integrated head unit by the substrate 50 having LEDs, the lens array 52 composed of a plurality of lenses, the housing 54, and the housing support member 55.

[0075] (Engaging claw) As shown in FIGS. 11 and 12, the exposure head 4 has engaging claws 55b and 55c which are the first engaging portions. The engaging claws 55b and 55c are provided on the housing support member 55 of the exposure head 4 and engage with the elevating duct 69 by snap fit (see FIG. 18).

[0076] In the housing support member 55 of the exposure head 4, the bottom surface portion 55D between the opening 55a at one end (front side) in the longitudinal direction and the adjacent opening 55a is defined as the first bottom surface portion 55D1. Similarly, the bottom surface portion 55D between the opening 55a at the other end (rear side) in the longitudinal direction and the adjacent opening 55a is defined as the second bottom surface portion 55D2. An engaging claw 55b that engages with the elevating duct 69 is provided on the lower surface of the first bottom surface portion 55D1. An engaging claw 55c that engages with the elevating duct 69 is provided on the lower surface of the second bottom surface portion 55D2. The first bottom surface portion 55D1 and the second bottom surface portion 55D2, that is, the bottom surface portion 55D, are opposing portions that face the upper surface portion 69U of the elevating duct 69 (see FIG. 18).

[0077] The engaging claws 55b and 55c, which are the first engaging portions, are formed to project toward the elevating duct 69 on the bottom surface portion 55D in the moving direction of the elevating duct 69 to be described later, and further extend in the axial direction of the photosensitive drum 2 orthogonal to the projecting direction.

[0078] Specifically, the engaging claws 55b and 55c of the exposure head 4 are formed to project toward the elevating duct 69 and have a substantially L-shaped configuration that extends in the axial direction of the photosensitive drum 2 orthogonal to the projecting direction. As will be described later, the exposure head 4 is slid so that the claw tips of the substantially L-shaped engaging claws 55b and 55c engage with the edges of the engaging holes 69b and 69c by snap fit and become integral with the elevating duct 69 (see FIG. 18).

[0079] (Elevating Duct) The image forming apparatus 100 includes an elevating duct 69. The elevating duct 69 will be described with reference to FIGS. 16 and 17. FIG. 16 is a cross-sectional view taken along the line X-X in FIG. 14. FIG. 17 is a cross-sectional view taken along the line Y-Y in FIG. 14.

[0080] The elevating duct 69 is an exposure support member that detachably supports the exposure head 4, and is provided on the apparatus main body of the image forming apparatus 100 together with a cartridge tray 30 to be described later.

[0081] The elevating duct 69 is provided between a developing support member 301 that supports the developing unit 24 of the cartridge tray 30, which will be described later, and a drum support member 302 that supports the drum unit 23. The elevating duct 69 is movably provided between the developing support member 301 and the drum support member 302 of the cartridge tray 30 at an exposure position (see FIG. 16) where the photosensitive drum 2 is exposed and a retracted position (see FIG. 17) retracted from the exposure position. Both longitudinal ends of the elevating duct 69 are supported from below by a rotating arm 65, which will be described later. The elevating duct 69 is moved by the rotating arm 65 in a direction intersecting the axial direction of the photosensitive drum 2 (the direction of arrow G shown in FIG. 16) integrally with the exposure head 4. The elevating duct 69 is moved to the exposure position or the retracted position by the rotation of the rotating arm 65 (see FIGS. 16 and 17).

[0082] The elevating duct 69 has a longitudinal shape extending in the front-rear direction (the axial direction of the photosensitive drum) similar to the exposure head 4 so as to support the entire exposure head 4, and the central portion thereof has a shape with openings at the top and bottom. The elevating duct 69 forms a duct in which one opening 69a (see FIG. 18) communicates with the opening 55a of the exposure head 4 and the other opening 64 communicates with the opening 61 of the duct unit 60. The elevating duct 69 supports the exposure head 4 and at the same time forms a part of a duct for cooling the exposure head 4.

[0083] The elevating duct 69 has an upper surface portion 69U (see FIG. 18) facing the bottom surface portion 55D of the housing support member 55. A plurality of openings 69a are provided in the upper surface portion 69U of the elevating duct 69 in the longitudinal direction which is the axial direction of the photosensitive drum 2. The elevating duct 69 has a duct left wall 69L, a duct right wall 69R facing the duct left wall 69L, a duct front wall 69F, and a duct rear wall 69B facing the duct front wall 69F (see FIG. 15). The duct left wall 69L, the duct right wall 69R, the duct front wall 69F, and the duct rear wall 69B are integrally provided on the upper surface portion 69U so as to surround the periphery of the upper surface portion 69U, that is, so as to surround the opening 69a provided in the upper surface portion 69U. Thereby, the elevating duct 69 is formed in a shape in which the upper surface portion 69U, the duct left wall 69L, the duct right wall 69R, the duct front wall 69F, and the duct rear wall 69B are integrally formed and has openings at the top and bottom. And the elevating duct 69 forms a duct (closed space) through which the air flow by the duct unit 60 described later flows to the exposure head 4 through between the duct walls and the opening 69a of the upper surface portion 69U (see FIG. 18).

[0084] The plurality of openings 69a are respectively provided at positions facing the plurality of openings 55a provided in the bottom surface portion 55D of the housing support member 55. In other words, the openings 69a of the elevating duct 69 are provided at positions facing the back surface of the substrate 50, similarly to the openings 55a of the housing support member 55. In other words, the elevating duct 69 has an opening 69a communicating with the opening 55a of the exposure head 4 (see FIG. 18).

[0085] The elevating duct 69 is formed in a hollow shape having no openings at positions facing the developing unit 24 and the drum unit 23 by these duct walls (duct left wall 69L, duct right wall 69R, duct front wall 69F, and duct rear wall 69B) and having openings at the top and bottom.

[0086] Therefore, the elevating duct 69 allows the airflow generated by the duct unit 60 to flow through the opening 64 described later and the opening 69a between the duct left wall 69L and the duct right wall 69R to the back surface of the substrate 50 of the exposure head 4. Thus, the elevating duct 69 can allow the airflow generated by the duct unit 60 to flow to the back surface of the substrate 50 of the exposure head 4 without leaking to the sides of the adjacent developing unit 24 or drum unit 23, and can reduce the scattering of toner inside the apparatus.

[0087] Furthermore, as shown in FIG. 14, the elevating duct 69 has a first engaging portion 69d and a second engaging portion 69e that engage with the rotating arm 65 at both longitudinal ends. The first engaging portion 69d is provided outside the duct front wall 69F at one longitudinal end. Also, the first engaging portion 69d is provided outside the region where the FFC connector 57 is provided outside the duct front wall 69F at one longitudinal end. The second engaging portion 69e is provided outside the duct rear wall 69B at the other longitudinal end.

[0088] Therefore, the region (front range Lm) where the first engaging portion 69d is provided and the region (rear range Lm) where the second engaging portion 69e is provided are provided outside the duct region (range La) surrounded by the duct walls 69F and 69B of the opening (opening 64, opening 69a) of the elevating duct 69. In other words, the duct region (range La) surrounded by the duct walls 69F and 69B of the opening of the elevating duct 69 is provided between the region (front range Lm) where the first engaging portion 69d is provided and the region (rear range Lm) where the second engaging portion 69e is provided.

[0089] Note that the range Lc shown in FIG. 14 is the region where the FFC connector 57 of the exposure head 4 is provided, is outside the duct region indicated by the range La, and is provided between the duct region and the region where the first engaging portion 69d shown by the front range Lm is provided.

[0090] In addition, the range La forming the duct includes most of the substrate 50 on which the LED 51 is mounted. By blowing an air current onto this range La, sufficient cooling of the exposure head 4 becomes possible. Note that the range Lc is the mounting portion of the FFC connector 57 of the signal line that transmits the drive signal to the substrate 50 on which the LED 51 is mounted. Although no opening for forming a duct is provided in the range Lc, as described above, it is configured such that sufficient cooling is possible in the range La.

[0091] As a result, the air taken in from the outside of the apparatus by the duct unit 60 described later is blown from the opening 55a of the exposure head 4 onto the back surface of the substrate 50 through the elevating duct 69. Further, the air current blown from the opening 55a of the exposure head 4 onto the back surface of the substrate 50 is exhausted to the outside of the apparatus by the duct unit 60 through the elevating duct 69.

[0092] (Engagement hole) As shown in FIG. 18, the elevating duct 69 has engagement holes 69b and 69c which are the second engagement portions. The engagement holes 69b and 69c which are the second engagement portions are engaged with the engagement claws 55b and 55c which are the first engagement portions of the exposure head 4 by snap fit.

[0093] In the elevating duct 69, the upper surface portion 69U between the opening 69a at one end (front side) in the longitudinal direction and the adjacent opening 69a is defined as the first upper surface portion 69U1. Similarly, the upper surface portion 69U between the opening 69a at the other end (rear side) in the longitudinal direction and the adjacent opening 69a is defined as the second upper surface portion 69U2. An engagement hole 69b for engaging with the engagement claw 55b of the exposure head 4 is provided in the first upper surface portion 69U1. An engagement hole 69c for engaging with the engagement claw 55c of the exposure head 4 is provided in the second upper surface portion 69U2. The first upper surface portion 69U1 and the second upper surface portion 69U2, that is, the upper surface portion 69U, faces the bottom surface portion 55D of the exposure head 4 (housing support member 55) and is a support portion for detachably supporting the exposure head 4.

[0094] The engaging holes 69b and 69c, which are the second engaging parts, are formed on the upper surface part 69U facing the exposure head 4 at positions corresponding to the engaging claws 55b and 55c.

[0095] Accordingly, the exposure head 4 is configured to be detachable from the image forming apparatus 100. Move the exposure head 4 so that the engaging claws 55b and 55c of the exposure head 4 are respectively dropped into the inside of the engaging holes 69b and 69c of the elevating duct 69, and bring the bottom surface part 55D of the exposure head 4 into contact with the upper surface part 69U of the elevating duct 69. That is, move the exposure head 4 in a direction perpendicular to the axial direction with respect to the elevating duct 69 to engage the engaging claws 55b and 55c in the protruding direction with respect to the engaging holes 69b and 69c.

[0096] Thereafter, by moving the exposure head 4 along the upper surface part 69U of the elevating duct 69, the engaging claws 55b and 55c of the exposure head 4 are respectively engaged with the engaging holes 69b and 69c of the elevating duct 69 by snap fit.

[0097] That is, move the exposure head 4 in the axial direction with respect to the elevating duct 69 to engage the engaging claws 55b and 55c in the extending direction perpendicular to the protruding direction with respect to the engaging holes 69b and 69c. In this way, the exposure head 4 is connected to the elevating duct 69 in the image forming apparatus 100, and the exposure head 4 is integrated with the elevating duct 69. The procedure for removing the exposure head 4 from the elevating duct 69 is performed in the reverse procedure of the above-described procedure. Note that the replacement and attachment / detachment configuration of the exposure head will be described in detail later.

[0098] (Cartridge Tray) The image forming apparatus 100 also includes a cartridge tray 30. The cartridge tray 30 will be described with reference to FIGS. 8, 9, 14, 15, 16, and 17. FIGS. 8, 9, and 14 are perspective views of the cartridge tray 30. FIG. 15 is a view of the cartridge tray 30 seen from below.

[0099] The cartridge tray 30 is a support member that supports the above-described drum unit 23 and developing unit 24, guides and supports the attachment and detachment operations along the axial direction of the photosensitive drum 2. The cartridge tray 30 pivotally supports the pivot shaft 102a of the inner door 102 so that the inner door 102 can rotate within a predetermined range.

[0100] The cartridge tray 30 is provided for each image forming unit. Each cartridge tray 30 has a developing support member 301 that guides and supports the attachment and detachment operation of the developing unit 24 along the axial direction of the photosensitive drum 2, and a drum support member 302 that guides and supports the attachment and detachment operation of the drum unit 23 along the axial direction of the photosensitive drum 2. The cartridge tray 30 has the developing support member 301 and the drum support member 302 integrally formed. Note that the cartridge tray 30 is not limited to the configuration provided for each image forming unit.

[0101] The elevating duct 69 is movably disposed between the developing support member 301 and the drum support member 302 of the cartridge tray 30. Between the developing support member 301 and the drum support member 302, the first engaging portion 69d and the second engaging portion 69e at both longitudinal ends of the elevating duct 69 are supported by the rotation arm 65 from below. The rotation arm 65 is rotatably provided on the developing support member 301 of the cartridge tray 30. The exposure head 4 is removably attached to the elevating duct 69 movably disposed on the cartridge tray 30. In other words, the cartridge tray 30 is a support member that supports the exposure head 4, guides and supports the attachment and detachment operation along the axial direction of the photosensitive drum 2.

[0102] (Developing support member) The developing support member 301 is a developing support member that guides and supports the developing unit 24 in the axial direction of the photosensitive drum, and is a longitudinally shaped member extending in the axial direction of the photosensitive drum 2. The developing support member 301 includes a first developing guide portion 301a, a second developing guide portion 301b facing the first developing guide portion 301a, and a developing bottom portion 301c provided between the first developing guide portion 301a and the second developing guide portion 301b. Further, the developing support member 301 has a third developing guide portion 301f. The first developing guide portion 301a, the second developing guide portion 301b, the developing bottom portion 301c, and the third developing guide portion 301f of the developing support member 301 are integrally formed.

[0103] The developing bottom portion 301c faces the bottom portion 24D of the frame of the developing unit 24 with a space therebetween, and is provided over the longitudinal direction which is the axial direction of the photosensitive drum 2. The first developing guide portion 301a is provided at one end side in the short direction orthogonal to the longitudinal direction of the developing bottom portion 301c, and is provided between the lifting duct 69 and the developing unit 24 so as to separate the lifting duct 69 from the developing unit 24. The second developing guide portion 301b is provided at the other end side in the short direction of the developing bottom portion 301c, and is provided so as to face the first developing guide portion 301a. The first developing guide portion 301a and the second developing guide portion 301b each contact the frame of the developing unit 24 and guide the developing unit 24 inserted and removed in the longitudinal direction over the longitudinal direction.

[0104] Also, the first developing guide portion 301a and the second developing guide portion 301b engage with the exposure head holding member 506 and guide the exposure head holding member 506 inserted and removed in the longitudinal direction over the longitudinal direction. Further, the third developing guide portion 301f engages with the engaging portion 506a of the exposure head holding member 506 together with the first developing guide portion 301a and the second developing guide portion 301b to guide the exposure head holding member 506.

[0105] The first developing guide portion 301a has an opposing portion 301d that faces the first inclined surface 69L1 of the elevating duct 69. The opposing portion 301d has a first tray inclined surface that is inclined in the same manner as the first inclined surface 69L1 of the elevating duct 69.

[0106] The first developing guide portion 301a has a partition portion 301e on the downstream side in the moving direction from the retracted position of the elevating duct 69 toward the exposure position, relative to the opposing portion 301d. The partition portion 301e is provided between the exposure head 4 and the developing unit 24 so as to separate the exposure head 4 and the developing unit 24 located at the exposure position shown in FIG. 16. The partition portion 301e is the end portion (upper end portion) on the developing sleeve side in the first developing guide portion 301a.

[0107] As shown in FIGS. 2, 8, and 16, the developing support member 301 (cartridge tray 30) is disposed directly below the developing unit 24. The developing support member 301 (cartridge tray 30) forms a duct, which is a closed space, with its upper surface and the bottom surface of the developing unit 24, and functions not only as a guide for the attaching and detaching operation of the developing unit but also as an intermediate path for the developing cooling air flow.

[0108] The duct (closed space) formed by the upper surface of the cartridge tray 30 (developing support member 301) and the upper surface of the developing unit 24 has an opening at one end side (front side) in its longitudinal direction that communicates with the opening 41a of the front duct 41 that takes in air from outside the apparatus through the opening 102c of the inner door 102. The duct between the developing unit 24 and the developing support member 301 forms a single closed space that communicates with the front duct 41 and the rear duct 42 (see FIG. 22).

[0109] (Restricting portion of the cartridge tray) Here, with reference to FIG. 34, the restricting portion 301g of the cartridge tray 30 will be described. FIG. 34 is an enlarged perspective view of the vicinity of the restricting portion 301g of the cartridge tray 30.

[0110] As shown in FIG. 34, the cartridge tray 30 of this embodiment includes a restricting portion 301g. In the exposure head replacement operation, the restricting portion 301g abuts against the hole portion 506c and the restricting portion 506i, which are the engaging portions of the exposure head holding member 506, to restrict the forward and backward movement of the exposure head holding member 506 at predetermined positions (the first position and the second position) (see FIG. 36). When moving the exposure head holding member 506 in the front-rear direction, the restricting portion 301g restricts the movement of the exposure head holding member 506 in both the forward direction F, which is one of the front-rear directions, and the backward direction B, which is the other direction.

[0111] Here, the restricting portion 301g includes two restricting surfaces 301g1 and 301g2. The restricting surface 301g1 is a first restricting surface that restricts the forward movement F of the exposure head holding member 506. The restricting surface 301g2 is a second restricting surface that restricts the backward movement B of the exposure head holding member 506. The restricting surfaces 301g1 and 301g2 engage with the hole portion 506c of the exposure head holding member 506 at the first position where the FFC 58 is inserted into and removed from the exposure head 4, and restrict the forward and backward movement of the exposure head holding member 506. The restricting surface 301g1 engages with the restricting portion 506e of the exposure head holding member 506 at the second position where the exposure head 4 is attached to and detached from the lifting and lowering duct 69, and restricts the forward movement of the exposure head holding member 506.

[0112] In this way, the restricting portion 301g restricts both the forward movement F and the backward movement B of the exposure head holding member 506. However, the restricting portion 301g is disposed at a position in the cartridge tray 30 that does not restrict the forward and backward movement of the developing unit 24. Thereby, the restricting portion 301g does not prevent the forward and backward movement of the developing unit 24.

[0113] In this embodiment, a configuration in which the restricting portion 301g is provided as a member separate from the developing support member 301 is illustrated, but it is not limited thereto. For example, the restricting portion 301g may be directly provided on the developing support member 301. The detailed functions of the restricting portion 301g will be described later.

[0114] (Drum support member) The drum support member 302 is a photoreceptor support member that guides and supports the drum unit 23 in the attachment and detachment operation along the axial direction of the photosensitive drum, and is a longitudinally shaped member extending in the axial direction of the photosensitive drum 2. The drum support member 302 includes a first drum guide portion 302a, a second drum guide portion 302b facing the first drum guide portion 302a, and a drum bottom surface portion 302c provided between the first drum guide portion 302a and the second drum guide portion 302b. The first drum guide portion 302a, the second drum guide portion 302b, and the drum bottom surface portion 302c of the drum support member 302 are integrally formed.

[0115] The drum bottom surface portion 302c faces the bottom surface portion 23D of the frame of the drum unit 23 and is provided over the longitudinal direction which is the axial direction of the photosensitive drum 2. The first drum guide portion 302a is provided at one end side in the short direction orthogonal to the longitudinal direction of the drum bottom surface portion 302c, and is provided between the lifting duct 69 and the drum unit 23 so as to separate the lifting duct 69 and the drum unit 23. The second drum guide portion 302b is provided at the other end side in the short direction of the drum bottom surface portion 302c and is provided so as to face the first drum guide portion 302a. The first drum guide portion 302a and the second drum guide portion 302b each abut against the frame of the drum unit 23 and guide the drum unit 23 inserted and removed in the longitudinal direction over the longitudinal direction.

[0116] The first drum guide portion 302a has a facing portion 302d facing the second inclined surface 69R1 of the lifting duct 69. The facing portion 302d has a second tray inclined surface inclined in the same manner as the second inclined surface 69R1 of the lifting duct 69.

[0117] (Relationship between the cartridge tray and the lifting duct) Here, the relationship between the cartridge tray 30 and the lifting duct 69 will be described.

[0118] The elevating duct 69 is movably disposed between the first developing guide portion 301a and the first drum guide portion 302a in the cartridge tray 30, and is moved between the exposure position shown in FIG. 16 and the retracted position shown in FIG. 17 by the rotation of the rotation arm 65. That is, the first developing guide portion 301a and the first drum guide portion 302a of the cartridge tray 30 function as guide members for guiding the elevating duct 69 in its moving direction.

[0119] Further, the exposure head 4 is detachably attached to the elevating duct 69, so that the opening 55a of the exposure head 4 and the opening 69a of the elevating duct 69 communicate with each other and become integrated with the exposure head 4. The elevating duct 69 is separated from the developing unit 24 by the first developing guide portion 301a of the cartridge tray 30, and is separated from the drum unit 23 by the first drum guide portion 302a of the cartridge tray 30. Further, at the exposure position shown in FIG. 16, the gap between the elevating duct 69 and the first developing guide portion 301a is sealed by a seal 72 which is a sealing member. Similarly, at the exposure position shown in FIG. 16, the gap between the elevating duct 69 and the first drum guide portion 302a is sealed by a seal 71 which is a sealing member.

[0120] Furthermore, at the pressing position shown in FIG. 16 of the developing unit 24, the gap between the developing unit 24 and the cartridge tray 30 is sealed by a seal 70 which is a sealing member.

[0121] In this way, the cartridge tray 30 and the elevating duct 69 disposed between the first developing guide portion 301a and the first drum guide portion 302a of the cartridge tray 30 form a duct which is a closed space communicating with the opening 55a of the exposure head 4.

[0122] (Relationship between the cartridge tray, the elevating duct, and the duct unit) Also, the cartridge tray 30 and the elevating duct 69 form an opening 64 communicating with the opening 61 of the duct unit 60 on the side facing the duct unit 60.

[0123] (Developing Stage) The image forming apparatus 100 includes a developing stage 31 that is slidable along the axial direction of the photosensitive drum 2. The developing stage 31 will be described with reference to FIGS. 19, 20, and 16. FIGS. 19 and 20 are side views of the developing stage 31 as viewed from the right direction. FIG. 16 is a cross-sectional view taken along the line X-X in FIG. 14.

[0124] In FIG. 19, the inner door 102 is in the closed state, the developing unit 24 is in a position close to the photosensitive drum 2, and the exposure head 4 is in an exposure position close to the photosensitive drum 2. In FIG. 20, the inner door 102 is in the open state, the developing unit 24 is in a retracted position from the photosensitive drum 2, and the exposure head 4 is in a retracted position retracted from the exposure position.

[0125] The developing stage 31, which is a slide member, is provided so as to be movable in the axial direction of the photosensitive drum 2. The developing stage 31 moves in one direction in the axial direction in conjunction with the opening operation of the inner door 102, and moves in the other direction in the axial direction in conjunction with the closing operation of the inner door 102. The developing stage 31 is provided so as to be movable with respect to the developing support member 301 of the cartridge tray 30. The developing stage 31 has an elongated shape (longitudinal shape) extending in the axial direction of the photosensitive drum 2, and includes a developing pressure roller 32, a developing pressure roller 33, a developing stage link 34, an arm retracting member 68F, and an arm retracting member 68B.

[0126] The developing stage link 34 is fixed to the front end portion of the developing stage 31 and engages with the inner door 102 pivotally supported by the cartridge tray 30. The developing pressure roller 32 is fixed to one side (front side) in the longitudinal direction of the developing stage 31, and the developing pressure roller 33 is fixed to the other side (rear side) in the longitudinal direction of the developing stage 31. The developing pressure roller 32 and the developing pressure roller 33 are provided at positions facing the developing unit 24.

[0127] The developing pressure members 32 and 33 are developing engagement members that are moved in the same direction when the developing stage 31 is moved and engage with the developing unit 24. The developing pressure members 32 and 33 engage with the developing unit 24 to move the developing unit 24 to a developing position (see FIG. 19) close to the photosensitive drum 2 or a separated position (see FIG. 20) separated from the photosensitive drum 2.

[0128] The inner door 102 has a link engagement portion 102b that engages with the developing stage link 34. In the inner door 102, the link engagement portion 102b is provided on the side opposite to the portion covering the unit via the rotation shaft 102a.

[0129] As shown in FIG. 20, when the inner door 102 is open, the link engagement portion 102b that engages with the developing stage link 34 is located at a position closer to the rear end of the inner door 102 than the rotation shaft 102a. On the other hand, as shown in FIG. 19, when the inner door 102 is closed, the link engagement portion 102b is located at a position closer to the lower end of the inner door 102 than the rotation shaft 102a. Therefore, in accordance with the rotation of the inner door 102, the link engagement portion 102b of the inner door 102 moves in the rotation direction along a circular locus with the distance between the rotation shaft 102a and the link engagement portion 102b as the radius. That is, by opening the inner door 102 as shown in FIG. 20, the link engagement portion 102b also rotates and moves toward the rear of the apparatus.

[0130] As a result, the developing stage link 34 that engages with the link engagement portion 102b of the inner door 102 is slid rearward in the rearward direction B, which is the rear of the apparatus, and the two developing pressure members 32 and 33 integrally formed through the developing stage 31 also slide rearward in the rearward direction B. This means that, as shown in FIG. 20, the two developing pressure members 32 and 33 are disengaged from the holding position for holding the developing unit 24. When the developing pressure members 32 and 33 are disengaged from the holding position, the developing unit 24 moves downward in the downward direction D, which is the direction of retracting from the photosensitive drum 2 due to its own weight.

[0131] From the above description, it can be seen that when the inner door 102 is opened, the developing unit 24 retracts from the photosensitive drum 2. When closing the inner door 102, the developing unit 24 is moved and pressed in the direction of the photosensitive drum 2 by going through the reverse procedure of the opening operation.

[0132] In this way, as shown in FIG. 19, when the inner door 102 is closed, the developing stage 31 is slid forward in the forward direction F. At this time, the developing pressure members 32 and 33 engage with the developing unit 24, and the developing unit 24 is moved upward (in the upward direction U) along the slopes of the developing pressure members 32 and 33 of the developing stage 31. As a result, the developing sleeve 5 of the developing unit 24 is moved in the direction approaching the photosensitive drum 2 of the drum unit 23, and is moved to the developing position (see FIG. 16) where the developing sleeve 5 is close to the photosensitive drum 2.

[0133] Also, as shown in FIG. 20, when the inner door 102 is opened, the developing stage 31 is slid backward in the backward direction B. At this time, the developing pressure members 32 and 33 engage with the developing unit 24, and the developing unit 24 is moved downward (in the downward direction D) along the slopes of the developing pressure members 32 and 33 of the developing stage 31. As a result, the developing sleeve 5 of the developing unit 24 is moved in the direction away from the photosensitive drum 2 of the drum unit 23, and is moved to the separated position (see FIG. 17) where the developing sleeve 5 is separated from the photosensitive drum 2. During non-developing shown in FIG. 20, the developing sleeve 5 is separated from the photosensitive drum 2 as compared with the developing state shown in FIG. 19.

[0134] Further, the developing station 31 includes an arm retracting member 68F for rotating a rotating arm 65 which is a rotating member, and an arm retracting member 68B. The arm retracting member 68F and the arm retracting member 68B are integrally formed with the developing station 31 (see FIG. 17). The arm retracting member 68F is fixed to one side in the longitudinal direction of the developing station 31 (front side of the apparatus), and is provided on a surface opposite to the developing pressure pad 32. The arm retracting member 68B is fixed to the other side in the longitudinal direction of the developing station 31 (rear side of the apparatus), and is provided on a surface opposite to the developing pressure pad 33. The arm retracting member 68F and the arm retracting member 68B are moved in the same direction as the developing station 31 is slid in the front-rear direction in conjunction with the opening and closing operation of the inner door 102, and rotate the rotating arm 65.

[0135] That is, when the developing station 31 moves in one direction (rear direction B) in the axial direction in conjunction with the opening operation of the inner door 102, the arm retracting member 68F and the arm retracting member 68B are moved in the same direction and engage with the rotating arm 65. Thereby, the rotating arm 65 rotates in one direction and moves the exposure head 4 integrated with the lifting duct 69 to the retracted position (see FIG. 17). On the other hand, when the developing station 31 moves in the other direction (front direction F) in the axial direction in conjunction with the closing operation of the inner door 102, the arm retracting member 68F and the arm retracting member 68B are moved in the same direction, and the engagement with the rotating arm 65 is released. Thereby, the rotating arm 65 rotates in the other direction and moves the exposure head 4 integrated with the lifting duct 69 to the exposure position (see FIG. 16).

[0136] (Rotating arm) As shown in FIG. 14, the rotating arm 65 is a rotating member that moves the exposure head 4 between an exposure position close to the photosensitive drum 2 (see FIG. 16) and a retracted position retracted from the exposure position (see FIG. 17).

[0137] The rotating arm 65, which is a rotating member, is rotatably provided on the developing support member 301 of the cartridge tray 30. One end of the rotating arm 65 in the left - right direction perpendicular to the axial direction of the photosensitive drum 2 is rotatably supported about an axis parallel to the axial direction. Also, the other end of the rotating arm 65 in the left - right direction supports both ends of a region (range Lm) outside the openings (opening 69a, opening 64) of the lifting duct 69 in the axial direction.

[0138] The rotating arm 65 presses the bottom surfaces at both longitudinal ends of the lifting duct 69 upward by the force of an arm pressing spring (not shown), which is a biasing member. In FIG. 16, the exposure head 4 is disposed in proximity to the photosensitive drum 2, and this state is maintained by the rotating arm 65 pressing the bottom surfaces at both ends of the lifting duct 69 upward. This pressing is ensured by a predetermined spring pressure of the arm pressing spring.

[0139] In this way, the rotating arm 65 does not directly press the exposure head 4, but presses the lifting duct 69 that supports the exposure head 4.

[0140] Note that the operation of the rotating arm 65 that moves the exposure head 4 to the exposure position or the retracted position obtains its power from the sliding movement of the developing stay 31 that retracts the developing unit 24, but it may also obtain power through another member interlocked with the inner door 102.

[0141] (Positioning pins of the exposure head) Here, the positioning pins 45F, 45B of the exposure head 4 will be described.

[0142] The housing 54 of the exposure head 4 is provided with a positioning pin 45F, which is a positioning shaft, and a positioning pin 45B. Both the positioning pin 45F and the positioning pin 45B are examples of metal pins. The housing 54 is a conductive member having conductivity, and the positioning pins 45F and 45B are also members having conductivity. The positioning pin 45F and the positioning pin 45B are respectively fixed to both ends in the longitudinal direction of the housing 54. The positioning pin 45F is fixed to the housing 54 on one side (front side) of the lens array 52 in the axial direction of the photosensitive drum 2, and protrudes from both sides of the housing 54 in the optical axis direction of the lens array 52. The positioning pin 45B is fixed to the housing 54 on the other side (rear side) of the lens array 52 in the axial direction of the photosensitive drum 2, and protrudes from both sides of the housing 54 in the optical axis direction of the lens array 52.

[0143] In addition, in the positioning pin 45F, the upper end (top) of the portion protruding above the housing 54 is located below the upper surface (light emitting surface) of the lens array 52 fixed to the housing 54. On the other hand, in the positioning pin 45B, the upper end (top) of the portion protruding above the housing 54 is located above the upper surface (light emitting surface) of the lens array 52 fixed to the housing 54.

[0144] The positioning pins 45F and 45B adjust the position of the positioning surface at the tip of the shaft with respect to the housing 54 in order to ensure the distance between the surface of the photosensitive drum 2 and the light emitting surface of the lens array 52 of the exposure head 4 with high precision, and are caulked to the housing 54. Note that the fixing of the positioning pins 45F and 45B to the housing 54 is not limited to this. For example, the metal positioning pin 45F and the positioning pin 45B may be fixed to the metal housing 54 by welding. Thus, in this embodiment, the positioning pins 45F and 45B are integrated with the housing 54.

[0145] Then, when the positioning pins 45F and 45B of the exposure head 4 are moved to the exposure position, they abut against predetermined locations (for example, the engaging portions 26F and 26B of the drum bearing 26 shown in FIGS. 23 and 24) of the drum unit 23 that supports the photosensitive drum 2. Thereby, at the exposure position, the distance between the exposure head 104 and the surface of the photosensitive drum 2 is kept constant. Also, the exposure head 4 is fixed not only in distance from the photosensitive drum 2 but also in angle by the positioning pins 45F and 45B.

[0146] Also, although not shown, the pressing position where the engaging boss 66 of the rotating arm 65 presses the lifting duct 69, the contact position between the positioning pins 45F and 45B and the predetermined location of the drum unit 23, and the center position of the photosensitive drum 2 are arranged substantially in a straight line at the exposure position.

[0147] With this arrangement, since the exposure head 4 is pressed toward the center of the photosensitive drum 2, no extra rotational moment is applied to the lifting duct 69. This means that there is no component in the pressing force that promotes the inclination of the exposure head 4 with respect to the photosensitive drum 2, which leads to the positioning accuracy of distance and angle and the stability of the repeated attachment and detachment operations.

[0148] Furthermore, as shown in FIGS. 23 and 24, the positioning pins 45F and 45B are additionally fitted at their lower end circumferential surfaces to the auxiliary fitting portions 30h and 30i of the cartridge tray 30 in a direction orthogonal to the optical axis direction of the exposure head 4 and in a direction orthogonal to the axis direction of the photosensitive drum 2. Thereby, even when a slight rotational moment is generated due to the weight of the components, surface properties, dimensional errors, etc., stable positioning accuracy of distance and angle and repeated attachment and detachment operations can be achieved.

[0149] (Relationship between the engaging claw and the engaging hole) Here, with reference to FIG. 27, the relationship between the engaging claw of the exposure head 4 and the engaging hole of the lifting duct 69 will be described in more detail. Here, the relationship between the engaging claw 55b of the exposure head 4 and the engaging hole 69b of the lifting duct 69 will be described, but the relationship between the engaging claw 55c of the exposure head 4 and the engaging hole 69c of the lifting duct 69 is the same.

[0150] As shown in FIG. 27, the engaging claw 55b has elasticity, and a recess 55f is provided at the extended tip of the engaging claw 55b. At the edge of the engaging hole 69c corresponding to the recess 55f, a convex portion 69f that engages with the recess 55f is provided. The convex portion 69f provided at the edge of the engaging hole 69c is disposed at a position corresponding to the recess 55f provided at the tip of the engaging claw 55b at the completion position of the sliding operation of the exposure head 4 with respect to the elevating duct 69, that is, the completion position of mounting.

[0151] Immediately before the completion of the sliding operation of the exposure head 4 in the direction of arrow K, the tip of the engaging claw 55b interferes with the convex portion 69f and the engaging claw 55b is elastically deformed, so that the sliding operation force of the exposure head 4 increases once compared with the operation force immediately before the interference. Thereafter, immediately, the recess 55f of the engaging claw 55b reaches the convex portion 69f, and the recess 55f and the convex portion 69f engage with each other, so that the sliding operation force of the exposure head 4 decreases. That is, when the exposure head 4 is moved in the extending direction with respect to the elevating duct 69, the engaging claw 55b is elastically deformed until the recess 55f and the convex portion 69f engage with each other, thereby changing the operation force for moving the exposure head 4 in the extending direction. By this rapid increase and decrease of the sliding operation force of the exposure head 4, a click feeling indicating that the sliding operation of the exposure head 4 has been completed can be provided.

[0152] In this way, by changing the sliding operation force of the exposure head 4 due to the elastic deformation of the engaging claw 55b until the recess 55f of the engaging claw 55b and the convex portion 69f of the engaging hole 69b engage with each other, the completion of mounting of the exposure head 4 can be clearly presented.

[0153] Also, as described above, as shown in FIGS. 23 and 24, the positioning pins 45F and 45B of the exposure head 4 are additionally fitted to the auxiliary fitting portions 30h and 30i of the cartridge tray 30 on the circumferential surface of their lower ends. This fitting is performed simultaneously by the sliding operation of the exposure head 4 in the rearward direction B.

[0154] Furthermore, in this embodiment, the grounding connection between the housing 54 of the exposure head 4 and the image forming apparatus 100 is also performed simultaneously by the backward B sliding operation of the exposure head 4 described above. The housing 54 of the exposure head 4 and the positioning pins 45F and 45B are clamped and fixed to establish electrical continuity. The grounding connection with the image forming apparatus 100 is achieved when the peripheral surface of the positioning pin 45F of the exposure head 4 comes into contact with a conductive member (not shown) provided on the cartridge tray 30 on the apparatus side. The conductive member has conductivity. Specifically, the conductive member is made of a metallic thin plate. Therefore, sufficient contact pressure can be obtained by contact and deformation due to the sliding operation of the exposure head 4. The conductive member is electrically connected to the frame sheet metal of the image forming apparatus 100 after passing through a circuit board on which a harness, a resistance element for noise removal, and a capacitor are mounted.

[0155] In this way, the positioning pin 45F of the exposure head 4 can be electrically connected to the conductive member by a sliding operation, and the exposure head 4 can be connected to the ground. Thereby, the exposure head 4 can be easily connected to the ground or the like to suppress the generation of radiation noise such as electromagnetic waves. That is, stable grounding characteristics can be obtained only by the sliding operation for mounting the exposure head 4 on the lifting duct 69.

[0156] (Configuration of FFC, FFC Guide) Next, the configuration of the FFC 58 and the FFC guide 503 will be described with reference to FIGS. 28 to 30. FIG. 28 is a perspective view showing the configuration of the exposure head 4, the FFC 58, the substrate 502, and the FFC guide 503. FIG. 29(a) is a cross-sectional view taken from the front side of the image forming apparatus 100 in FIG. 28. FIG. 29(b) is an enlarged view of the vicinity of the biasing member 504 in FIG. 29(a). FIG. 30 is an enlarged view of the vicinity of the contact 58a in FIG. 29(a). However, the exposure head 4 is not shown in FIG. 30 for the sake of explanation.

[0157] (Configuration of FFC) The image forming apparatus 100 includes a plurality of FFCs 58 (58Y, 58M, 58C, 58K) that electrically connect each exposure head 4 (4Y, 4M, 4C, 4K) and the substrate 502. As described above, in the present embodiment, the substrate 502 is disposed on the left side of the image forming apparatus 100, and the exposure head 4 is disposed on the right side of the substrate 502. Each FFC 58 electrically connects the exposure head 4 and the substrate 502 by connecting one end thereof to the exposure head 4 and the other end thereof to the substrate 502.

[0158] As shown in FIG. 28, each FFC 58 connects the FFC connector 57 provided in each exposure head 4 and each connector 501 provided in the substrate 502. The FFCs 58 (58Y, 58M, 58C, 58K) are stacked and arranged.

[0159] As shown in FIG. 30, each FFC 58 (58Y, 58M, 58C, 58K) has, at the one end, a contact 58a electrically connected to the FFC connector 57 of the exposure head 4 and a reinforcing plate 58b that is a reinforcing portion for reinforcing the contact 58a. The reinforcing plate 58b is fixed to the surface of the FFC 58 opposite to the contact 58a with a double-sided tape or the like.

[0160] Each FFC 58 (58Y, 58M, 58C, 58K) has a contact (not shown) connected to each connector 501 (501Y, 501M, 501C, 501K) provided in the substrate 502 at the other end.

[0161] Further, the reinforcing plate 58b has a protruding portion 58c protruding from the surface opposite to the contact 58a. The reinforcing plate 58b is provided with the protruding portion 58c, and has a shape that allows it to be pinched with a finger when inserting and removing the FFC 58 from the FFC connector 57.

[0162] Here, as shown in FIGS. 29(a) and 30, in the first posture where the exposure head 4 is in a posture of exposing the photosensitive drum 2, the reinforcing plate 58b and the protruding portion 58c are arranged on the right side of the contact point 58a. In other words, the FFC 58 is connected to the connector of the exposure head 4 held in the first posture such that the reinforcing plate 58b and the protruding portion 58c are arranged on the right side of the contact point 58a in the left - right direction (second direction) of the image forming apparatus 100.

[0163] Also, as shown in FIGS. 40(a) and 40(b), in the second posture which is a holding posture for replacing the exposure head 4, the reinforcing plate 58b and the protruding portion 58c are arranged above the contact point 58a. In other words, the FFC 58 is connected to the connector of the exposure head 4 held in a second posture different from the first posture such that the reinforcing plate 58b and the protruding portion 58c are arranged above the contact point 58a in the up - down direction (third direction) of the image forming apparatus 100.

[0164] (Configuration of the FFC guide) The image forming apparatus 100 further includes an FFC guide 503 as a guide member for holding each FFC 58 (58Y, 58M, 58C, 58K) along the left - right direction. The FFC guide 503 is provided so as to extend in the left - right direction (second direction). The FFC guide 503 is arranged directly below the exposure head 4 inside the image forming apparatus 100. Here, the FFC guide 503 is linearly arranged in the left - right direction directly below the FFC connector 57 (57Y, 57M, 57C, 57K) of the exposure head 4.

[0165] The FFC guide 503 is a guide member provided in the image forming apparatus 100 for regulating the position of the FFC 58. The region between one end and the other end of the FFC 58 is held inside the image forming apparatus 100 by this FFC guide 503. As shown in Fig. 29(a), the FFC guide 503 has a first opening 503a and a second opening 503b (503bY, 503bM, 503bC, 503bB) through which the FFC 58 passes. The first opening 503a is disposed on the left side with respect to the second opening 503b. The first opening 503a is a first through-hole disposed on one side (left side) in the left-right direction in the FFC guide 503, and is provided on the substrate 502 side with respect to the four exposure heads 4. The second opening 503b is a second through-hole disposed on the other side (right side) in the left-right direction in the FFC guide 503, and is provided for each exposure head 4. The first opening 503a and the second opening 503b are provided in the FFC guide 503 and are linearly arranged in the left-right direction.

[0166] Here, a configuration in which the first opening (first through-hole) 503a and the second opening (second through-hole) 503b are provided in the FFC guide 503 has been illustrated, but the present invention is not limited thereto. For example, a configuration in which the first through-hole is provided in a member other than the FFC guide 503 may be employed. Also, a configuration in which the second through-hole is provided in a member other than the FFC guide 503, such as the elevating duct 69 or the cartridge tray 30, may be employed. In this case, the second through-hole is preferably provided on the side where the FFC holding member 507 is disposed.

[0167] Further, as shown in Figs. 28 and 29(a), a biasing member 504 for biasing the FFC 58 is attached to the FFC guide 503. The biasing member 504 is a member that regulates the FFC 58 from moving with respect to the FFC guide 503 by biasing the FFC 58 in the vertical direction with respect to the FFC guide 503, and is a member such as a bundling clamp. The FFC 58 can move with respect to the FFC guide 503 by removing the biasing member 504. Therefore, the FFC 58 is configured to be held movably with respect to the FFC guide 503 under predetermined conditions.

[0168] Also, as shown in FIG. 29(b), a cover member 505 for restricting the FFC 58 from falling downward is attached to the FFC guide 503. However, the cover member 505 is a member for simplifying the mold for molding the FFC guide 503, and a configuration may be adopted in which a wall having a similar function is provided on the FFC guide 503 itself.

[0169] Next, the path of the FFC 58 from the substrate 502 to the exposure head 4 will be described.

[0170] As shown in FIG. 28, the other end of each FFC 58 is connected to each connector 501 provided on the substrate 502 disposed on the left side of the main body of the image forming apparatus 100. The FFCs 58 connected to the connectors 501 of the substrate 502 on the left side of the main body of the image forming apparatus 100 are laminated with the FFC 58Y, FFC 58M, FFC 58C, and FFC 58K on the left side of the main body and are bent so as to go from the left side to the right side of the main body. The laminated FFC 58 penetrates through the first opening 503a of the FFC guide 503 and enters the inside of the FFC guide 503 as shown in FIG. 29(a). At this time, the laminated FFC 58 is biased from above to below by a biasing member 504 provided on the FFC guide 503. The FFC 58 is held so as not to move in the left-right direction by the frictional force generated by being sandwiched between the biasing member 504 and the FFC guide 503.

[0171] Note that the vertically laminated order of the FFCs 58 sandwiched between the biasing member 504 and the FFC guide 503 is yellow (Y), magenta (M), cyan (C), and black (B) from above. That is, the FFCs 58 sandwiched between the biasing member 504 and the FFC guide 503 are laminated in order from above to below in the vertical direction so as to be in the same order as the arrangement order of the exposure heads 4 arranged from the left side to the right side.

[0172] The FFC 58 that enters the interior of the FFC guide 503 is arranged to extend in the left - right direction along the FFC guide 503. When it enters below the second opening 503bY of the FFC guide 503, only the FFC 58Y separates upward and is bent, and is arranged to face the FFC connector 57Y of the exposure head 4Y. The FFC 58Y is connected to the FFC connector 57Y of the exposure head 4Y, electrically connecting the substrate 502 and the exposure head 4Y. After separating from the FFC 58Y, the stacked FFCs 58 (58M, 58C, 58B) are arranged to extend in the left - right direction from the left side to the right side of the main body along the FFC guide 503. The subsequent path of the FFC 58 is the same as that of the yellow image forming unit 1Y. In each of the image forming units 1M, 1C, 1K, when it enters below each second opening 503b, the uppermost FFC 58 separates upward and is bent, and is arranged to face the FFC connector 57 of the exposure head 4. The FFC 58 arranged to face the exposure head 4 is connected to the FFC connector 57 of the exposure head 4, electrically connecting the substrate 502 and the FFC connector 57.

[0173] As described above, the substrate 502 and each exposure head 4 are connected by each FFC 58. In this embodiment, a configuration with four image forming units 1Y, 1M, 1C, 1K assuming a color multifunction machine is used, but a configuration with one image forming unit 1K of a monochrome multifunction machine may also be used.

[0174] (Replacement tool) Next, with reference to FIGS. 31 to 33, a replacement tool used for replacing the exposure head 4 and the FFC 58 in the image forming apparatus 100 will be described. FIG. 31 is a diagram showing an exposure head holding member 506 which is one of the exposure head - FFC replacement tools, (a) is a perspective view, (b) is a top view, (c) is a cross - sectional view taken along line A - A in (b) seen from the right side, and (d) is a front view. FIG. 32 is a diagram showing an FFC holding member 507 which is one of the exposure head - FFC replacement tools, (a) is a perspective view, (b) is a top view, (c) is a right side view, and (d) is a rear view. FIG. 32 is a front view showing a sheet member 508 which is one of the exposure head - FFC replacement tools.

[0175] The replacement tool for the exposure head 4 and the FFC 58 is, for example, a replacement tool for removing the exposure head 4 or the FFC 58 from inside the image forming apparatus 100 and attaching a new exposure head 4 or FFC 58 when the exposure head 4 or the FFC 58 malfunctions. This replacement tool is a member used by a service technician in the market.

[0176] The replacement tool for the exposure head 4 and the FFC 58 is composed of three members: an exposure head holding member 506, an FFC holding member 507, and a sheet member 508, and any one or all of them can be attached to the housing, cover, etc. of the image forming apparatus 100 (not shown). Here, a configuration in which the image forming apparatus 100 includes a replacement tool for the exposure head 4 and the FFC 58 is illustrated, but it is not limited thereto. For example, the replacement tool for the exposure head 4 and the FFC 58 may not be included in the image forming apparatus 100 but may be included with a new exposure head 4 or FFC 58 for replacement, or may be a configuration held by a service technician as a tool. Further, the replacement tool for the exposure head 4 and the FFC 58 is not limited to a configuration of three members, i.e., the exposure head holding member 506, the FFC holding member 507, and the sheet member 508, and may be any one member or two members. Also, for the replacement tool for the exposure head 4 and the FFC 58, any one of the three members, i.e., the exposure head holding member 506, the FFC holding member 507, and the sheet member 508, may be included in the image forming apparatus, and the other members may be included with a new exposure head 4 or FFC 58 for replacement, or may be a configuration held by a service technician as a tool.

[0177] Next, the directions of the exposure head holding member 506 and the FFC holding member 507 are defined as follows. When replacing the exposure head 4 and the FFC 58, with the exposure head holding member 506 and the FFC holding member 507 held by the cartridge tray 30, the front side plate side with respect to the apparatus main body is defined as the front side (front side or front face side), and the rear side plate side is defined as the rear side (rear side or back side). Also, when taking the photosensitive drum 2K on which an electrostatic latent image for the black toner image is formed as a reference, the side on which the photosensitive drum 2Y on which an electrostatic latent image for the yellow toner image is formed is arranged is defined as the left side. When taking the photosensitive drum 2Y on which an electrostatic latent image for the yellow toner image is formed as a reference, the side on which the photosensitive drum 2K on which an electrostatic latent image for the black toner image is formed is arranged is defined as the right side. Further, the direction perpendicular to the front-rear direction and the left-right direction defined here and vertically upward is defined as the upward direction, and the direction perpendicular to the front-rear direction and the left-right direction defined here and vertically downward is defined as the downward direction. Similar to the above, the defined front direction F, rear direction B, right direction R, left direction L, upward direction U, and downward direction D are shown in FIGS. 31 and 32.

[0178] (Exposure head holding member) The exposure head holding member 506 is one of the replacement tools used for replacing the exposure head 4 and the FFC 58. The exposure head holding member 506 is a movable member that engages with the cartridge tray 30 and is movable in the longitudinal direction (front-rear direction) of the exposure head 4 during the replacement operation of the exposure head 4 and the FFC 58, and has a function of temporarily holding the exposure head 4. In other words, the exposure head holding member 506 is not limited to the replacement tool used for replacing the exposure head 4, and may be at least a holder that holds the exposure head 4.

[0179] In this embodiment, the exposure head holding member 506 is arranged on the left side (developer unit side) in the left-right direction via the exposure head 4 held at the exposure position. That is, the exposure head holding member 506 is arranged on the developer support member 301 of the cartridge tray 30 on the developer unit side in the left-right direction via the exposure head 4 mounted on the image forming apparatus 100.

[0180] The exposure head holding member 506 includes an engaging portion 506a that is movably engaged with the developing support member 301 in the front-rear direction (the first direction). As shown in FIG. 31(a), the exposure head holding member 506 includes a plurality of engaging portions 506a at different positions in the front-rear direction. In the replacement operation of the exposure head 4, the engaging portion 506a engages with the developing support member 301 provided on the cartridge tray 30 and is guided in the front-rear direction (see FIGS. 35(a) and (b)). In this embodiment, a configuration in which three engaging portions 506a are provided at different positions in the front-rear direction is illustrated, but the present invention is not limited thereto. For example, a configuration in which two or less engaging portions 506a are provided, or a configuration in which four or more engaging portions 506a are provided may be adopted.

[0181] Further, as shown in FIG. 31(c), the exposure head holding member 506 includes an inclined portion 506b and a hole portion 506c, and a flat portion 506d and a restricting portion 506e. These are the shapes for the developing support member 301 to hold the exposure head holding member 506 at the FFC insertion / removal position, which is the first position, and the exposure head attachment / detachment position, which is the second position, respectively, during the replacement operation of the exposure head 4 (see FIGS. 36(a) to 36(d)).

[0182] The first position is the FFC insertion / removal position where the FFC 58 is inserted into and removed from the exposure head 4. The second position is the exposure head attachment / detachment position where the exposure head 4 is attached to and detached from the image forming apparatus 100.

[0183] The hole portion 506c is a first movement restricting portion that restricts the movement of the exposure head holding member 506 in the front-rear direction at the first position (FFC insertion / removal position) where a part of the exposure head 4 is exposed outside the image forming apparatus 100 in the front-rear direction.

[0184] The inclined portion 506b slopes upward from below as it goes in the rearward direction B, and is provided immediately before the hole portion 506c in the rearward direction B. When the exposure head holding member 506 is inserted into the development support member 301 of the cartridge tray 30 in the rearward direction B, the inclined portion 506b abuts against the regulating portion 301g of the cartridge tray 30. When the exposure head holding member 506 is further inserted in the rearward direction B, as shown in FIG. 36(a), it is pushed up by the regulating portion 301g, and the exposure head holding member 506 is lifted. As shown in FIG. 36(b), the inclined portion 506b gets out of contact with the regulating portion 301g beyond the regulating portion 301g. Then, due to the self-weight of the exposure head holding member 506, the hole portion 506c engages with the regulating portion 301g. At this time, a clicking feeling is generated due to the drop caused by the self-weight of the exposure head holding member 506, and the operator can know that the exposure head holding member 506 has engaged with the first position. In a state where the hole portion 506c and the regulating portion 301g are engaged, the exposure head holding member 506 cannot be inserted into or removed from the cartridge tray 30, and the movement in the front-rear direction is restricted at the first position. The position where the hole portion 506c and the regulating portion 301g engage is the FFC insertion / removal position (the first position) for inserting and removing the FFC 58 with respect to the FFC connector 57 of the exposure head 4. By restricting the movement of the exposure head holding member 506 in the front-rear direction in this way, it becomes possible to stabilize and simplify the FFC insertion / removal operation.

[0185] The regulating portion 506e is a second movement regulating portion that restricts the movement of the exposure head holding member 506 in the front-rear direction at a second position (exposure head attachment / detachment position) where the exposure head 4 is located inside the image forming apparatus 100 more than the first position in the front-rear direction.

[0186] The flat portion 506d is provided immediately after the hole portion 506c in the rearward direction B and immediately before the restricting portion 506e. After lifting the exposure head holding member 506 to release the engagement between the hole portion 506c and the restricting portion 301g, the flat portion 506d further inserts the exposure head holding member 506 in the rearward direction B, so that, as shown in FIG. 36(c), it is in a state of riding on the restricting portion 301g. When the flat portion 506d further inserts the exposure head holding member 506 in the rearward direction B, as shown in FIG. 36(d), the contact with the restricting portion 301g is released beyond the restricting portion 301g. Then, due to the self-weight of the exposure head holding member 506, the restricting portion 506e engages with the restricting portion 301g. In a state where the restricting portion 506e and the restricting portion 301g are engaged, the exposure head holding member 506 cannot be inserted into or removed from the cartridge tray 30, and the movement in the front-rear direction is restricted at the second position. The position where the restricting portion 506e and the restricting portion 301g engage is the exposure head attachment / detachment position (second position) where the exposure head 4 is attached to and detached from the elevating duct 69. By restricting the movement of the exposure head holding member 506 in the front-rear direction in this way, it becomes possible to stabilize and simplify the exposure head attachment / detachment operation.

[0187] Further, as shown in FIG. 31(b), the exposure head holding member 506 includes a restricting portion 506f, a restricting portion 506g, a protruding portion 506j, and a guide portion 506m. These are parts for assisting the operator in operating the exposure head 4 during the replacement operation of the exposure head 4 (see FIGS. 38(a) to 38(c)).

[0188] The exposure head holding member 506 includes a restricting portion 506f on the rear side in the front-rear direction in a state of being engaged with the developing support member 301. The restricting portion 506f is a first restricting portion that restricts the position of the exposure head 4 in the front-rear direction (first direction). As shown in FIG. 37(a), the restricting portion 506f is located behind the lens array 52 of the exposure head 4 held by the elevating duct 69 and in front of the positioning pin 45B in a state where the exposure head holding member 506 is engaged with the developing support member 301. Further, the restricting portion 506f is located below the upper end of the positioning pin 45B in a state where the exposure head holding member 506 is engaged with the developing support member 301. Thereby, after the engagement with the elevating duct 69 is released, the restricting portion 506f abuts against the positioning pin 45B of the exposure head 4 further pulled forward in the forward direction F, and restricts the position of the exposure head 4 in the front-rear direction.

[0189] The exposure head holding member 506 includes a restricting portion 506g on the rear side in the front-rear direction in a state of being engaged with the developing support member 301. The restricting portion 506g is a third restricting portion that restricts the position of the exposure head 4 in the vertical direction (third direction). As shown in FIG. 37(b), the restricting portion 506g is located behind the lens array 52 of the exposure head 4 held by the elevating duct 69 and in front of the positioning pin 45B in a state where the exposure head holding member 506 is engaged with the developing support member 301. Further, the restricting portion 506g is located above the upper surface (upper surface of the housing 54) of the exposure head 4 held by the elevating duct 69 in a state where the exposure head holding member 506 is engaged with the developing support member 301. Thereby, even when the exposure head 4 whose engagement with the elevating duct 69 is released is lifted upward in the upward direction U, the restricting portion 506g abuts against the exposure head 4 and restricts the position of the exposure head 4 in the vertical direction.

[0190] The guide portion 506m is a restricting portion that restricts the locus of the positioning pin 45B of the exposure head 4 when rotating the exposure head 4 whose position is restricted by the restricting portion 506f and the restricting portion 506g counterclockwise (CCW direction) toward the seating surface 506h of the exposure head holding member 506. By restricting the rotation locus of the exposure head 4 by the guide portion 506m, the rotation operation of the exposure head 4 can be stably performed.

[0191] The protruding portion 506j engages with the opening 55a of the housing support member 55 of the exposure head 4, and is an engaging portion that serves as a fulcrum when rotating the exposure head 4 counterclockwise as described above. By engaging the exposure head 4 with the protruding portion 506j, the rotational operation of the exposure head 4 can be stably performed.

[0192] Further, as shown in FIGS. 31(b) and 31(d), the exposure head holding member 506 includes a seating surface 506h, a regulating portion 506i, a regulating portion 506k, and a regulating portion 506l. These are holding portions that stably hold the exposure head 4 during the replacement operation of the exposure head 4 (see FIG. 39).

[0193] The exposure head holding member 506 includes a seating surface 506h that is a holding portion for temporarily holding the exposure head 4 removed from the elevating duct 69. As shown in FIG. 31(c), the seating surface 506h has a height difference that decreases as it progresses from one side to the other in the front-rear direction (rearward direction B). That is, among the plurality of seating surfaces 506h provided in the front-rear direction, the height in the vertical direction of the rear seating surface 506h is lower than that of the front seating surface 506h. In addition, as shown in FIG. 31(d), the seating surface 506h has a height difference that decreases as it progresses from one side to the other in the left-right direction (leftward direction L). In other words, with respect to the exposure head 4 held by the elevating duct 69, the height in the vertical direction decreases as it progresses from the side closer to the exposure head 4 in the left-right direction to the side farther away. Here, for each seating surface 506h, the height in the vertical direction decreases from the right side to the left side in the left-right direction of the seating surface 506h. Therefore, the seating surface 506h is composed of a surface having height differences in the front-rear direction and the left-right direction in a state where the engaging portion 506a is engaged with the developing support member 301. In this embodiment, the seating surface 506h for holding the exposure head 4 is configured by the surfaces at the tips of a plurality of ribs provided at multiple locations in the front-rear direction, but it is not limited to this. For example, it may be configured by a single flat surface, and the number and position of the seating surfaces 506h may be appropriately provided as needed.

[0194] The restricting portion 506i is provided on the front side in the front-rear direction, abuts against the housing 54 of the exposure head 4 after rotating counterclockwise as described above, and is a holding portion that holds the exposure head 4. The restricting portion 506i is provided on one of the ribs provided at a plurality of locations in the front-rear direction. Here, an example is given of a configuration provided on the rib provided with the frontmost seating surface 506h among the ribs in the front-rear direction. The restricting portion 506i abuts against one side surface of the exposure head 4 at the seating surface 506h, and abuts against the upper surface intersecting the said side surface. That is, in the said rib, the restricting portion 506i is a surface intersecting the seating surface 506h. Note that, although an example is given of a configuration in which the restricting portion 506i is provided on one of the ribs provided at a plurality of locations in the front-rear direction, the present invention is not limited thereto.

[0195] The restricting portion 506k is provided on the rear side in the front-rear direction, abuts against the positioning pin 45B of the exposure head 4 after rotating counterclockwise as described above, and is a holding portion that holds the exposure head 4. The restricting portion 506k is a surface intersecting the rearmost seating surface 506h among the ribs provided at a plurality of locations in the front-rear direction. The restricting portion 506k abuts against the seating surface 506h at one side surface of the exposure head 4, and abuts against the tip of the positioning pin 45B protruding from the upper surface intersecting the said side surface.

[0196] The exposure head holding member 506 includes a restricting portion 506l on the front side in the front-rear direction in a state of being engaged with the development support member 301. The restricting portion 506l is a second restricting portion that restricts the position of the exposure head 4 in the left-right direction (second direction). As shown in FIG. 39, the restricting portion 506l abuts against the right end portion, which is the bottom surface portion of the exposure head 4 held by the seating surface 506h of the exposure head holding member 506, on the front side in the front-rear direction, and restricts the position of the exposure head 4 in the left-right direction.

[0197] Details of the usage procedure of the exposure head holding member 506 during the replacement operation will be described later.

[0198] (FFC Holding Member) The FFC holding member 507 is one of the replacement tools used for replacing the exposure head 4 and the FFC 58. The FFC holding member 507 has a function of engaging with the cartridge tray 30 during the replacement operation of the exposure head 4 and the FFC 58, guiding the FFC 58, and temporarily holding the FFC 58.

[0199] In this embodiment, the FFC holding member 507 is disposed on the right side in the left - right direction, which is on the opposite side of the exposure head holding member 506, via the exposure head 4 held at the exposure position. That is, the FFC holding member 507 is disposed on the drum support member 302 of the cartridge tray 30 on the drum unit side in the left - right direction via the exposure head 4 mounted on the image forming apparatus 100.

[0200] As shown in FIG. 32(b), the FFC holding member 507 includes an FFC holding portion 507a and an FFC holding portion 507b that temporarily hold the FFC 58 removed from the exposure head 4. The two FFC holding portions 507b are provided to hold one surface side of the FFC 58. The FFC holding portion 507a is provided between the two FFC holding portions 507b and is provided to hold the other surface side of the FFC 58. During the replacement operation of the exposure head 4 and the FFC 58, as shown in FIG. 44, the FFC holding member 507 sandwiches and temporarily holds the FFC 58 between the FFC holding portion 507a and the FFC holding portion 507b.

[0201] Further, the FFC holding member 507 includes a guide portion 507c that guides the FFC 58 from the left - right direction and the up - down direction to the front - back direction. As shown in FIGS. 32(b) to 32(d), the guide portion 507c forms a surface inclined with respect to the left - right direction, up - down direction, and front - back direction of the image forming apparatus 100. The inclined directions are the direction from left to right, the direction from top to bottom, and the direction from back to front of the image forming apparatus. That is, as shown in FIGS. 32(b) to 32(d), the guide portion 507c is substantially parallel to the straight line connecting the upper - left - rear and lower - right - front of the main body. Therefore, the guide portion 507c guides the moving direction of the FFC 58 to be converted from the left - right direction and the up - down direction to the front - back direction.

[0202] This enables a function of guiding the FFC 58 and the sheet member 508 to be converted from the left-right direction, which is the first moving direction, to the front-back direction, which is the second moving direction, during the exposure head - FFC replacement operation (Fig. 46).

[0203] Also, as shown in Figs. 32(c) and 32(d), the FFC holding member 507 includes a restricting portion 507d, a restricting portion 507e, and a restricting portion 507f. The restricting portion 507d, the restricting portion 507e, and the restricting portion 507f each have a surface orthogonal to the front-back direction, the left-right direction, and the up-down direction, respectively. During the exposure head - FFC replacement operation, the restricting portion 507d, the restricting portion 507e, and the restricting portion 507f engage with the drum support member 302 of the cartridge tray 30 to restrict the position of the FFC holding member 507 in their respective directions. In particular, the position of the FFC holding member 507 in the front-back direction is restricted by the restricting portion 507d engaging with the drum support member 302 of the cartridge tray 30. The restricting portion 507d is provided on a part of an elastically deformable shape such as a patching claw, and by displacing it by pushing with a finger or the like, the engagement with the cartridge tray 30 is released, and it becomes possible to move in the front-back direction (see Figs. 42(a) and 42(b)).

[0204] Further, the bottom surface 507g of the FFC holding member 507 is arranged to overlap with the recovery toner duct 302f, which is a part of the toner conveyance path provided on the drum support member 302 of the cartridge tray 30. At the position where the restricting portion 507d of the FFC holding member 507 described above engages with the drum support member 302 of the cartridge tray 30, the bottom surface 507g of the FFC holding member 507 is arranged to overlap with the recovery toner duct 302f of the cartridge tray 30.

[0205] Details of the usage procedure of the FFC holding member 507 during the replacement operation will be described later.

[0206] (Sheet member) The sheet member 508 is one of the replacement tools used for replacing the exposure head 4 and the FFC 58. As shown in FIG. 33, the sheet member 508 has a longitudinal shape. The sheet member 508 has an FFC holding portion 508a and a protruding portion 508b.

[0207] The sheet member 508 has an FFC holding portion 508a, which is a cable holding portion that holds the contact 58a of the FFC 58 at one end. Here, the FFC holding portion 508a is composed of three arm portions 508aa, 508ab, and 508ac. The arm portions 508aa, 508ab, and 508ac are integrally provided on the base portion 508c of the sheet member 508. The arm portions 508aa, 508ab, and 508ac are provided by cutting out a part of the base portion 508c of the sheet member 508 and are provided within a region in the short direction orthogonal to the longitudinal direction of the base portion 508c. The arm portions 508aa, 508ab, and 508ac are provided in the order of 508aa, 508ab, and 508ac in the longitudinal direction of the sheet member 508. Also, one side in the short direction of the arm portions 508aa and 508ac is integrated with the base portion 508c, and the other side in the short direction is provided as a free end. The arm portion 508ab is provided such that the other side in the short direction is integrated with the base portion 508c and the one side in the short direction is a free end, and is provided between the arm portions 508aa and 508ac. Thereby, the sheet member 508 holds the FFC 58 at the FFC holding portion 508a and can move integrally with the FFC 58, and has a function of passing the FFC 58 through the FFC guide 503. Note that the contact 58a of the FFC 58 is a contact that is electrically connected to the FFC connector 57 of the exposure head 4. Note that although the configuration in which the FFC holding portion 508a is provided at one end in the longitudinal direction of the sheet member 508 is illustrated, the present invention is not limited to this, and any configuration provided on one end side in the longitudinal direction of the sheet member 508 may be used.

[0208] The sheet member 508 has, at the other end, a protruding portion 508b that restricts the position so that the sheet member 508 does not enter the inside of the FFC guide 503 during the exposure head - FFC replacement operation. As shown in Fig. 48(a), the protruding portion 508b has a length (width w1) protruding on both sides in the short - hand direction that is longer than the width w2 of the portion of the sheet member 508 other than the protruding portion 508b. Specifically, the protruding portion 508b protrudes such that the length (width w1) in the short - hand direction is longer than the first opening 503a (first through - hole) and the second opening 503b (second through - hole) of the FFC guide 503. Here, the width of the portion of the sheet member 508 other than the protruding portion 508b refers to the length (width w1) in the short - hand direction orthogonal to the longitudinal direction of the sheet member 508, and is provided slightly wider than the length of the FFC58 in the short - hand direction.

[0209] Also, the sheet member 508 has a longitudinal shape in which the length L1 from one end (the end on the FFC holding portion 508a side) to the other end (the end on the protruding portion 508b side) is longer than the length from the first opening 503a arranged on one side in the left - right direction to the second opening 503b arranged on the other side in the left - right direction via the FFC guide 503. In other words, the sheet member 508 has a length such that, via the FFC guide 503, the other end (protruding portion 508b) is exposed from the first opening 503a arranged on one side in the left - right direction, and the FFC holding portion 508a is exposed from the second opening 503b arranged on the other side in the left - right direction.

[0210] Here, the sheet member 508 is a resin sheet. In this embodiment, it is a PET sheet (resin) with a thickness between 0.15 [mm] and 0.3 [mm] and a tensile elastic modulus between 3500 [MPa] and 4500 [MPa]. Note that these materials, thicknesses, etc. are examples, and the sheet member is not limited to these.

[0211] Details of the usage procedure of the sheet member 508 during the replacement operation will be described later.

[0212] (Replacement of Exposure Head, FFC) Next, with reference to FIGS. 21, 25, 26, 27, and 28 to 49, the replacement of the exposure head 4 and the replacement of the FFC 58 will be described in detail. FIG. 21 is a cross-sectional view taken along the line X-X in FIG. 14, similar to FIG. 16, with the drum unit 23 and the developing unit 24 not shown, and is a cross-sectional view of the exposure head 4, the elevating duct 69, and the cartridge tray 30 as seen from the front.

[0213] The replacement of the exposure head 4 and the FFC 58 is performed using the replacement tool described above. The replacement of the exposure head 4 and the FFC 58 is performed in the state shown in FIG. 21 where the drum unit 23 and the developing unit 24 are removed from the cartridge tray 30. Note that in the state where the photosensitive drum (drum unit) is removed from the cartridge tray 30, the exposure head 4 is configured to be manually movable from the retracted position to the exposure position. Therefore, when replacing and attaching / detaching the exposure head 4 and the FFC 58, as shown in FIG. 21, it is performed with the exposure head 4 manually moved to the exposure position.

[0214] The exposure head 4 and the FFC 58 are configured to be detachable from the image forming apparatus 100. The procedures for replacing the exposure head 4 and the FFC 58 will be described in detail. FIGS. 35 to 49 are diagrams showing the procedures for replacing the exposure head 4 and the FFC 58.

[0215] The operation of replacing the exposure head 4 and the operation of replacing the FFC 58 are composed of the following four procedures. Procedure 1 is to remove the old exposure head 4 from the image forming apparatus 100. Procedure 2 is to remove the old FFC 58 from the image forming apparatus 100. Procedure 3 is to attach the new FFC 58 to the image forming apparatus 100. Procedure 4 is to attach the new exposure head 4 to the image forming apparatus 100.

[0216] However, when only the exposure head 4 is replaced without replacing the FFC, steps 2 and 3 are omitted, and only steps 1 and 4 are performed. Also, when only the FFC 58 is replaced without replacing the exposure head 4, the operations of steps 1 to 4 are performed, but the following operations may not be performed in steps 1 and 4. That is, in step 1, the operation of taking out the exposure head 4 held in the second posture by the exposure head holding member 506 to the outside of the image forming apparatus 100 together with the exposure head holding member 506 may not be performed. Also, in step 4, the operation of holding the exposure head 4 in the second posture on the exposure head holding member 506 pulled out to the outside of the image forming apparatus 100 and attaching it to the image forming apparatus 100 together with the exposure head holding member 506 may not be performed.

[0217] (Step 1) Step 1 will be described. Here, the replacement operation of the exposure head and the FFC in the black image forming unit 1K arranged on the rightmost side in the left - right direction of the image forming apparatus 100 will be exemplified and described.

[0218] First, as shown in FIGS. 35(a) and 35(b), the exposure head holding member 506 is inserted rearward in the B direction into the developing support member 301 of the cartridge tray 30. Then, the first developing guide portion 301a and the second developing guide portion 301b of the developing support member 301 engage with the outer shape of the exposure head holding member 506. Further, the third developing guide portion 301f of the developing support member 301 engages with the engaging portion 506a of the exposure head holding member 506. By engaging in this way, the exposure head holding member 506 is guided rearward in the B direction by the developing support member 301.

[0219] When the exposure head holding member 506 is inserted rearward in the B direction, as shown in FIG. 36(a), the inclined portion 506b of the exposure head holding member 506 abuts against the restricting portion 301g of the cartridge tray 30. When the exposure head holding member 506 is further inserted rearward in the B direction, the inclined portion 506b is pushed up by the restricting portion 301g, and the exposure head holding member 506 is pushed upward.

[0220] Insert the further exposure head holding member 506 backward in the B direction. As shown in Fig. 36(b), when the inclined portion 506b exceeds the restricting portion 301g, due to the self-weight of the exposure head holding member 506, the hole portion 506c of the exposure head holding member 506 enters and engages with the restricting portion 301g. At this time, a clicking sensation is generated due to the fall of the exposure head holding member 506 by its own weight, which can clearly inform the operator that it is engaged. In the state where the hole portion 506c and the restricting portion 301g are engaged, the exposure head holding member 506 cannot be inserted into or removed from the cartridge tray 30. The position where the hole portion 506c and the restricting portion 301g are engaged is the first position for inserting and removing the FFC 58 with respect to the FFC connector 57 of the exposure head 4 held by the exposure head holding member 506. With such a configuration, it becomes possible to stabilize and simplify the operation of inserting and removing the FFC 58 with respect to the exposure head 4.

[0221] Next, as shown in Fig. 36(c), by lifting the exposure head holding member 506 upward, the engagement between the hole portion 506c and the restricting portion 301g can be released, and the exposure head holding member 506 can be further inserted backward in the B direction. When the above-mentioned engagement is released and the exposure head holding member 506 is inserted backward in the B direction, the flat portion 506d of the exposure head holding member 506 is in a state of riding on the restricting portion 301g.

[0222] Insert the exposure head holding member 506 further backward in the B direction. As shown in Fig. 36(d), when the flat portion 506d exceeds the restricting portion 301g, due to the self-weight of the exposure head holding member 506, the restricting portion 506e of the exposure head holding member 506 engages with the restricting portion 301g. In the state where the restricting portion 506e and the restricting portion 301g are engaged, the exposure head holding member 506 cannot be inserted into or removed from the cartridge tray 30. The position where the restricting portion 506e and the restricting portion 301g are engaged is the second position for attaching and detaching the exposure head 4 to and from the lifting duct 69. With such a configuration, the exposure head holding member 506 is held by the developing support member 301 at the first position for inserting and removing the FFC 58 and the second position for attaching and detaching the exposure head 4, and it becomes possible to stabilize and simplify the exposure head attachment operation.

[0223] Next, an operation of placing the exposure head 4 on the exposure head holding member 506 is performed. Here, the engagement configuration between the exposure head 4 and the elevating duct 69 will be described. FIG. 26 is a cross-sectional view taken along the line W-W in FIG. 21, and is a cross-sectional view of the exposure head 4 mounted on the elevating duct 69. FIG. 27 is an enlarged cross-sectional view of the engagement portion shown in FIG. 26.

[0224] Note that the exposure head 4 engaged with the elevating duct 69 is in the first posture shown in FIGS. 16 and 29(a). The first posture is a posture in which the exposure head 4 exposes the photosensitive drum. Further, in the first posture, the LED chip 53 is disposed on the upper side in the vertical direction, and the FFC connector 57 is disposed on the lower side (see FIG. 13(a)). Further, as shown in FIGS. 29(a) and 30, the FFC 58 is connected to the FFC connector 57 of the exposure head 4 held in the first posture such that the contact 58a is disposed on the left side and the reinforcing plate 58b and the protruding portion 58c are disposed on the right side of the contact 58a in the left-right direction.

[0225] As shown in FIGS. 26 and 27, the engaging claws 55b and 55c of the exposure head 4 are formed to protrude toward the elevating duct 69, and have a substantially L-shaped configuration extending in the rearward direction B which is the sliding movement direction of the exposure head 4. Therefore, by the sliding movement in the rearward direction B, the claw tips of the substantially L-shaped engaging claws 55b and 55c engage with the edges of the engaging holes 69b and 69c. By this engagement, the exposure head 4 is mounted on the elevating duct 69 and becomes integral with the elevating duct 69. Further, by sliding the exposure head 4 in the forward direction F, the engagement between the claw tips of the substantially L-shaped engaging claws 55b and 55c and the engaging holes 69b and 69c is released (see FIG. 25). By this release of engagement, the exposure head 4 can be removed from the elevating duct 69.

[0226] Return to the description of Procedure 1. Pull out the exposure head 4 in the forward direction F to disengage it from the lifting duct 69 (see Fig. 25). When the exposure head 4 is further pulled out in the forward direction F, as shown in Fig. 37(a), the positioning pin 45B of the exposure head 4 abuts against the restricting portion 506f of the exposure head holding member 506 held in the second position, and the forward movement of the exposure head 4 is restricted. At this time, as shown in Fig. 37(b), there is a restricting portion 506g of the exposure head holding member 506 above the exposure head 4. Therefore, even if the exposure head 4 is lifted upward in the upward direction U, the housing 54 abuts against the restricting portion 506g, and the upward movement of the exposure head 4 is also restricted, and it remains in a predetermined position.

[0227] Next, as shown in the order of Figs. 38(a), 38(b), and 38(c), while rotating the exposure head 4 counterclockwise (CCW direction) when viewed from the front side, place it on and set it on the seating surface 506h of the exposure head holding member 506. At this time, the guide portion 506m shown in Fig. 37(a) restricts the rotation locus of the positioning pin 45B, and the protruding portion 506j shown in Fig. 39 engages with the opening 55a of the housing support member 55 to become a rotation fulcrum. Thereby, the exposure head 4 can be rotated stably. Further, as shown in Fig. 39, the exposure head 4 after being rotated as described above is stably held by the exposure head holding member 506 when the restricting portion 506i abuts against the housing 54, the restricting portion 506k abuts against the positioning pin 45B, and the restricting portion 506l abuts against the bottom surface portion 55D of the housing support member 55.

[0228] Here, as shown in FIGS. 31(c) and 31(d), the seating surface 506h of the exposure head holding member 506 is a surface having height differences in the left-right direction and the front-rear direction. That is, the seating surface 506h is such that the rear seating surface 506h in the front-rear direction is lower in the vertical direction than the front seating surface 506h in the front-rear direction, and each seating surface 506h is lower from the right side to the left side in the left-right direction. As a result, the exposure head 4 rotated in the counterclockwise direction when viewed from the front side of the apparatus is biased by its own weight against the seating surface 506h of the exposure head holding member 506 and is uniquely held on the exposure head holding member 506 as shown in FIG. 40(a). Further, as shown in FIG. 31(c), in the front-rear direction, the front seating surface 506h on the operator side is higher than the rear seating surface 506h, enabling the operator to easily perform the above-described rotation operation.

[0229] Note that the exposure head 4 rotated in the counterclockwise direction and set on the seating surface 506h of the exposure head holding member 506 is held by the exposure head holding member 506 in the second posture shown in FIGS. 39 and 40(a). The second posture is a posture different from the above-described first posture and is a holding posture for replacing the exposure head 4. Further, in the second posture, the LED chip 53 is disposed on the left side in the left-right direction and the FFC connector 57 is disposed on the right side. Also, as shown in FIGS. 40(a) and 40(b), the FFC 58 is connected to the FFC connector 57 of the exposure head 4 held in the second posture such that the contact point 58a is disposed on the lower side and the reinforcing plate 58b and the protruding portion 58c are disposed above the contact point 58a in the vertical direction.

[0230] Next, in order to remove the exposure head 4 held by the exposure head holding member 506 in the second posture, excess length processing of the FFC 58 connected to the exposure head 4 is performed. One end of the FFC 58 is connected to the FFC connector 57 of the exposure head 4, and the other end is connected to the connector 501 of the substrate 502 disposed on the left side of the main body of the image forming apparatus 100. As shown in FIG. 41(a), in the black image forming unit 1K, first, the other end of the FFC 58K is detached from the connector 501K of the substrate 502, and the biasing member 504 is detached from the FFC guide 503 to make the FFC 58K movable. When the FFC 58K is pushed from the left side to the right side (right direction R) in the left-right direction, as shown in FIG. 41(b), the FFC 58K moves to the right side (right direction R) within the FFC guide 503, and the moved FFC 58K passes through the second opening 503bK of the FFC guide 503. Since one end of the FFC 58K is connected to the FFC connector 57K and its movement is restricted, the FFC 58K that has passed through the second opening 503bK is fed out into the space on the drum support member 302 of the cartridge tray 30, as shown in FIG. 41(c). Then, the FFC 58K fed out into the space on the drum support member 302 forms a bent portion 58d that is more curved than before feeding between the second opening 503bK and the FFC connector 57K. At this time, the total length (excess length) Ld of the bent portion 58d is the length required for the operation of pulling out the exposure head 4 in the forward direction F. The bent portion 58d formed here is the portion from the portion immediately after passing through the second opening 503bK and exposed from the cartridge tray 30 to the end of the FFC 58 connected to the FFC connector 57K.

[0231] Next, as shown in FIG. 42(a), the FFC holding member 507 is inserted backward in the B direction into the drum support member 302 of the cartridge tray 30. At this time, as shown in FIG. 42(b), the guide portion 507c of the FFC holding member 507 is inserted so as to pass through the inside of the bent portion 58d of the FFC 58K. In other words, the guide portion 507c of the FFC holding member 507 is inside the bent portion 58d of the FFC 58K and penetrates between one end and the other end of the bent portion 58d. Here, one end of the bent portion 58d is the end of the FFC 58 connected to the FFC connector 57K. Also, the other end of the bent portion 58d is located below the one end and is the portion immediately after passing through the second opening 503bK and exposing from the cartridge tray 30. Then, the regulating portions 507e and 507f (see FIGS. 32(c) and 32(d)) of the FFC holding member 507 inserted in the backward B direction are engaged with and guided by the drum support member 302, and regulate the positions of the FFC holding member 507 in the left-right direction and the up-down direction, respectively. Further, the regulating portion 507d of the FFC holding member 507 is engaged with the engaging portion 302e provided on the drum support member 302 to regulate the position of the FFC holding member 507 in the front-rear direction. At this time, the bottom surface 507g of the FFC holding member 507 is disposed so as to overlap with the toner recovery duct 302f which is a part of the toner conveyance path. Thereby, the toner recovery duct 302f of the cartridge tray 30 is blocked by the FFC holding member 507.

[0232] Next, perform the operation of removing the FFC 58 from the FFC connector 57 of the exposure head 4. As described above, as shown in FIG. 36(d), the exposure head holding member 506 has the regulating portion 506e engaged with the regulating portion 301g, and the movement in the front-rear direction is regulated at the exposure head attachment / detachment position (second position), and it is in a state where it cannot be inserted or removed. Therefore, as shown in FIG. 36(c), by lifting the exposure head holding member 506 upward, the engagement between the regulating portion 506e and the regulating portion 301g is released, and the exposure head holding member 506 is pulled out in the forward direction F. At this time, the flat portion 506d is in a state of riding on the regulating portion 301g. While pulling out the exposure head holding member 506 from the cartridge tray 30 in the forward direction F as it is, when the flat portion 506d exceeds the regulating portion 301g as shown in FIG. 36(b), the hole portion 506c enters and engages with the regulating portion 301g due to the self-weight of the exposure head holding member 506. As described above, the position where the hole portion 506c engages with the regulating portion 301g is the FFC insertion / removal position (first position) for inserting / removing the FFC 58 with respect to the FFC connector 57 of the exposure head 4, and it is in the state shown in FIGS. 43(a) and 43(b).

[0233] At the FFC insertion / removal position shown in FIGS. 43(a) and 43(b), the exposure head holding member 506 is restricted from moving in the front-rear direction by the engagement between the hole portion 506c and the regulating portion 301g, and a part of the exposure head 4 is in a state of being exposed outside the image forming apparatus 100 in the front-rear direction. More specifically, at the FFC insertion / removal position, the exposure head 4 held by the exposure head holding member 506 is in a state where the FFC connector 57 is exposed outside from the front side plate 100F of the image forming apparatus 100.

[0234] At this FFC insertion / removal position, the operator holds the protruding portion 58c provided on the FFC 58 and pulls out the FFC 58 from the FFC connector 57 in the right direction R. Since the operator often works with the right hand, as described above, the reinforcing plate 58b and the protruding portion 58c are arranged above (in the upward direction U) the contact point 58a, facilitating the operation of pulling out the FFC 58 in the right direction R. Also, as shown in FIG. 43(b), the exposure head 4 held by the exposure head holding member 506 has better visibility and the FFC insertion / removal operation becomes easier because the FFC connector 57 is pulled out in front of the front side plate 100F. The FFC 58 removed from the exposure head 4 is sandwiched and held between the FFC holding portion 507a and the FFC holding portion 507b of the FFC holding member 507 as shown in FIG. 44. With the above configuration, as described above, it becomes possible to stabilize and simplify the FFC insertion / removal operation.

[0235] Next, an operation of removing the exposure head 4 from the image forming apparatus 100 is performed. As shown in FIG. 36(a), by lifting the exposure head holding member 506 upward, the engagement between the hole portion 506c and the restricting portion 301g can be released, and the exposure head holding member 506 can be further pulled out in the forward direction F. At this time, the inclined portion 506b of the exposure head holding member 506 is in a state of being pushed up by the restricting portion 301g. By pulling out the exposure head holding member 506 in the forward direction F as it is, the exposure head 4 can be removed from the image forming apparatus 100 together with the exposure head holding member 506 as shown in FIG. 45. With the above configuration, as described above, it becomes possible to stabilize and simplify the operation of removing the exposure head.

[0236] (Procedure 2) Procedure 2 will be described.

[0237] When Procedure 1 is completed, as shown in FIG. 45, the FFC 58K is held by the FFC holding member 507, and one end thereof is exposed to the outside (front side) from the front side plate 100F of the image forming apparatus 100. Further, the FFC 58K with one end held is folded back along the guide portion 507c in a direction intersecting the rear direction B as shown in FIG. 43(a), and passes through the second opening 503bK and passes through the inside of the FFC guide 503 in the left-right direction as shown in FIG. 41(b). Further, the other end of the FFC 58K passes through the first opening 503a and is exposed outside the FFC guide 503.

[0238] First, remove one end of the FFC 58K from the FFC holding portions 507a and 507b. Attach and hold one end of the removed FFC 58 to the FFC holding portion 508a of the sheet member 508 as shown in FIG. 46. Here, the FFC holding portion 508a is composed of arm portions 508aa, 508ab, and 508ac provided at three locations as shown in FIG. 46(b) in this embodiment. The FFC 58 is sandwiched and held by these three arm portions 508aa, 508ab, 508ac and the base portion 508c. Further, the arm portion 508ac closest to the tip of the FFC 58 is configured to hold the reinforcing plate 58b so that the FFC 58 and the sheet member 508 do not separate as shown in FIG. 46(c). Specifically, the arm portion 508ac closest to the tip of the FFC 58 enters between the protruding portion 58c and the FFC 58, and the arm portion 508ac is caught between the reinforcing plate 58b and the FFC 58, holding the reinforcing plate 58b so that the FFC 58 and the sheet member 508 do not separate. That is, one of the plurality of arm portions 508aa, 508ab, 508ac, the arm portion 508ac, enters between the reinforcing plate 58b and the FFC 58, 58Y, 58M, 58C, 58K, 658, 658Y, 658M, 658C, 658K... FFC and sandwiches the FFC between it and the base portion 508c. With this configuration, the FFC 58 and the sheet member 508 can move integrally.

[0239] Further, as shown in FIG. 46(c), the sheet member 508 holds the FFC 58 in a state where the contact 58a of the FFC 58 abuts against the base 508c of the sheet member 508. Thereby, the sheet member 508 protects the contact 58a so that the contact 58a of the FFC 58 does not slide against other members.

[0240] Here, when the FFC 58K in the state shown in FIG. 41(b) is pulled out in the left direction L, the FFC 58K and the sheet member 508 are pulled in the backward direction B shown in FIG. 46(a). The FFC 58 and the sheet member 508 are folded back by the guide portion 507c, pass through the second opening 503bK of the FFC guide 503, pass through the inside of the FFC guide 503, pass through the first opening 503a, and are pulled out from the left side of the main body as shown in FIG. 47(a). At this time, the FFC 58K is held by the sheet member 508 so as to pass through the inside of the FFC guide 503 as shown in FIG. 47(b). In other words, the FFC holding portion 508a of the sheet member 508 and the end portion of the FFC 58K are in a state of passing through the inside of the FFC guide 503 and being exposed to the outside from the first opening 503a. Further, as shown in FIG. 47(c), the protruding portion 508b of the sheet member 508 is in a state of being exposed to the front side of the image forming apparatus 100. Then, the FFC 58K is removed from the FFC holding portion 508a of the sheet member 508. By the above operations, the FFC 58 before replacement can be removed from the image forming apparatus 100, and at the same time, the sheet member 508 can be disposed inside the image forming apparatus 100.

[0241] Here, as described above, the sheet member 508 is a PET sheet with a thickness between 0.15 and 0.3 [mm] and a tensile elastic modulus between 3500 and 4500 [MPa]. When the thickness is thin or the tensile elastic modulus is low, the strength and stiffness of the sheet member 508 become weak, and the sheet member 508 may be damaged during the above replacement operation, or the sheet member 508 may buckle during the replacement operation, deteriorating the replacement workability. Also, when the thickness is thick, it cannot pass smoothly through the FFC guide 503, deteriorating the replacement workability. Further, when the tensile elastic modulus is high, the stiffness of the sheet member 508 becomes strong, and the resistance when guiding at the guide portion 507c becomes large, deteriorating the replacement workability. From the above, the sheet member 508 has a thickness between 0.15 [mm] and 0.3 [mm] and a tensile elastic modulus between 3500 [MPa] and 4500 [MPa].

[0242] Here, a case where the operator accidentally pulls the FFC 58K and the sheet member 508 too far to the left side (left direction L) in the left-right direction will be described with reference to FIG. 48. A protruding portion 508b is provided at an end of the sheet member 508 opposite to the FFC holding portion 508a that holds the FFC 58. Here, when the width w1 in the region t1 of the protruding portion 508b of the sheet member 508, the width w2 in the region t2 other than the protruding portion 508b, and the width w3 of the second opening 503b of the FFC guide 503 are considered, the relationship w1 > w3 > w2 holds.

[0243] That is, the sheet member 508 has a first region t1 (protruding portion 508b) that is wider than the second opening 503b of the FFC guide 503 and a second region t2 (base portion 508c) that is narrower than the second opening 503b. Thereby, the portion of the region t2 of the sheet member 508 (the base portion 508c including the FFC holding portion 508a) can pass through the second opening 503b of the FFC guide 503, but the portion of the region t1 (protruding portion 508b) cannot pass through. Therefore, when the operator pulls the FFC 58K and the sheet member 508 too far, as shown in FIGS. 48(a) and 48(b), the protruding portion 508b is caught by the second opening 503b and can serve as a stopper to prevent the sheet member 508 from coming out of the FFC guide 503.

[0244] Also, as shown in FIGS. 48(c) and 33, the overall length L1 of the sheet member 508 is longer than a distance 3D which is three times the distance D between the centers of adjacent photosensitive drums 2. That is, the overall length L1 of the sheet member 508 is longer than the distance 3D between the centers of the leftmost photosensitive drum 2Y which is one end side in the left - right direction (arrangement direction) and the rightmost photosensitive drum 2K which is the other end side among the plurality of photosensitive drums 2, 2Y, 2M, 2C, 2K. Further, the sheet member 508 has a longitudinal shape in which its overall length L1 is longer than the length from the first opening 503a which is the first through - hole, through the FFC guide 503, to the second opening 503b which is the second through - hole (here, the second opening 503bK). Here, the second opening 503b which is the second through - hole is the second opening 503bK at the position farthest from the substrate 502 in the left - right direction. Also, the overall length L1 of the sheet member 508 is the length from the FFC holding portion 508a which is one end to the protruding portion 508b which is the other end. By configuring in this way, at least one of the FFC holding portion 508a or the protruding portion 508b is in a state of protruding outside the image forming apparatus 100, and it becomes possible for an operator to work outside the image forming apparatus 100.

[0245] As described above, the configuration in which the first through - hole (the first opening 503a) and the second through - hole (the second opening 503b) through which the sheet member 508 passes are provided in the FFC guide 503 has been exemplified, but it is not limited thereto. For example, the first through - hole may be provided in a member other than the FFC guide 503, or the second opening 503b may be provided in other members such as the elevating duct 69 or the cartridge tray 30 via the FFC guide 503. The overall length L1 of the sheet member 508 may be set to be longer than the length from the first through - hole to the second through - hole via the FFC guide 503.

[0246] (Procedure 3) Procedure 3 will be described.

[0247] When the procedure 2 is completed, the sheet member 508 passes through the first opening 503a, and the FFC holding portion 508a is exposed from the left side of the main body. As shown in Fig. 47(a), a new FFC 58 is attached to the FFC holding portion 508a of the sheet member 508. Thereby, the FFC 58 and the sheet member 508 are integrated and movable. Here, when the sheet member 508 in the state shown in Fig. 47(c) is pulled out to the front side (forward direction F) of the main body, the FFC 58 and the sheet member 508 are pulled into the right direction R shown in Fig. 47(a). The FFC 58 and the sheet member 508 pass through the first opening 503a of the FFC guide 503 and pass through the inside of the FFC guide 503. The contact 58a side is turned inward by the guide portion 507c of the FFC holding member 507 while forming a loop, and is pulled out from the front side of the main body as shown in Fig. 46(a). At this time, the guide portion 507c of the FFC holding member 507 guides the moving direction of the FFC 58 and the sheet member 508 to be converted from the left-right direction (right direction R), which is the first moving direction, to the front-rear direction (forward direction F), which is the second moving direction. Further, the guide portion 507c forms a surface inclined with respect to the left-right direction and the up-down direction of the image forming apparatus 100, and the inclined direction is the direction from the upper left to the lower right of the image forming apparatus and the direction from the upper back to the lower front. Thereby, it is possible to smoothly change the moving direction (Fig. 47(c)).

[0248] The FFC 58K is held so as to pass through the FFC guide 503 as shown in Fig. 29(a). Further, as shown in Fig. 41(b), the other end of the FFC 58K is exposed on the left side of the image forming apparatus 100, and as shown in Fig. 46(a), one end of the FFC 58K is exposed on the front side of the image forming apparatus 100. Then, the FFC 58 is removed from the FFC holding portion 508a of the sheet member 508, and the removed FFC 58 is sandwiched and held between the FFC holding portion 507a and the FFC holding portion 507b of the FFC holding member 507 as shown in Fig. 44. By the above operations, the replaced FFC 58 can be attached to the image forming apparatus 100, and at the same time, the sheet member 508 can be taken out from the image forming apparatus 100.

[0249] (Procedure 4) Procedure 4 will be described.

[0250] First, as shown in FIG. 39, the exposure head 4 is set on the exposure head holding member 506. The exposure head 4 is stably held on the exposure head holding member 506 by the contact of the regulating portion 506i with the housing 54, the contact of the regulating portion 506k with the positioning pin 45B, and the contact of the regulating portion 506l with the bottom surface portion 55D of the housing support member 55.

[0251] Next, in the same manner as in Procedure 1, as shown in FIG. 44, the exposure head holding member 506 is inserted backward in the B direction into the developing support member 301 of the cartridge tray 30. Then, the exposure head holding member 506 engages with the developing support member 301 and is guided backward in the B direction by the developing support member 301.

[0252] When the exposure head holding member 506 is inserted backward in the B direction, as shown in FIG. 36(a), the inclined portion 506b of the exposure head holding member 506 abuts against the regulating portion 301g of the cartridge tray 30, and the exposure head holding member 506 is pushed upward. As shown in FIG. 36(b), when the inclined portion 506b passes over the regulating portion 301g, the regulating portion 301g enters and engages with the hole portion 506c of the exposure head holding member 506 due to the self-weight of the exposure head holding member 506. The position where the hole portion 506c and the regulating portion 301g engage is the first position for inserting and removing the FFC 58 with respect to the FFC connector 57 of the exposure head 4 held by the exposure head holding member 506, and the state shown in FIG. 44 is achieved.

[0253] Here, the operator holds the protrusion 58c provided on the FFC 58, removes the FFC 58 from the FFC holding member 507, and inserts it in the left direction L with respect to the FFC connector 57 of the exposure head 4 held in the second posture as shown in Fig. 43(a). Since the operator often works with the right hand, as described above, the protrusion 58c is arranged on the upper side (upward direction U), facilitating the insertion operation. Also, as shown in Fig. 43(b), the end portions of the FFC connector 57 of the exposure head 4 and the FFC 58 are pulled out in front of the front side plate 100F of the image forming apparatus 100, improving visibility and facilitating the operation. By adopting the above configuration, as described above, it becomes possible to stabilize and simplify the FFC insertion / removal operation.

[0254] Next, as shown in Fig. 36(c), by lifting the exposure head holding member 506 upward, the engagement between the hole portion 506c and the regulating portion 301g can be released, and the exposure head holding member 506 can be further inserted in the rearward direction B. When the above-mentioned engagement is released and the exposure head holding member 506 is inserted in the rearward direction B, the flat portion 506d of the exposure head holding member 506 is in a state of riding on the regulating portion 301g.

[0255] When the exposure head holding member 506 is further inserted in the rearward direction B and, as shown in Fig. 36(d), the flat portion 506d exceeds the regulating portion 301g, the regulating portion 506e of the exposure head holding member 506 and the regulating portion 301g engage with each other due to the self-weight of the exposure head holding member 506. In the state where the regulating portion 506e and the regulating portion 301g are engaged, the exposure head holding member 506 cannot be inserted / removed with respect to the cartridge tray 30. As described above, the position where the regulating portion 506e and the regulating portion 301g engage is the second position for attaching / detaching the exposure head 4 to / from the elevating duct 69. After arranging the exposure head holding member 506 at the second position, the engagement with the cartridge tray 30 is released by elastically deforming the regulating portion 507d of the FFC holding member 507 or the like, and the FFC holding member 507 is pulled out in the forward direction F and removed from the image forming apparatus 100.

[0256] Next, the operation of placing the exposure head 4 on the elevating duct 69 is performed. The exposure head 4 is held on the seating surface 506h of the exposure head holding member 506 in the second posture shown in FIG. 38(c). Next, as shown in the order of FIGS. 38(c), 38(b), and 38(a), while rotating the exposure head 4 in the clockwise direction (CW direction) when viewed from the front side, the bottom surface 55D of the housing support member 55 is set to rest on the upper surface portion 69U of the elevating duct 69. At this time, the guide portion 506m of the exposure head holding member 506 held at the second position restricts the locus of the positioning pin 45B of the exposure head 4, so that the exposure head 4 can be rotated stably. Also, as shown in FIG. 25, the engaging claws 55b, 55c of the exposure head 4 are dropped inside the engaging holes 69b, 69c of the elevating duct 69, respectively. That is, the engaging claws 55b, 55c of the exposure head 4 are engaged with the engaging holes 69b, 69c of the elevating duct 69 in the protruding direction. At the same time here, as shown in FIG. 49(a), the lower end of the positioning pin 45F of the exposure head 4 is dropped into the auxiliary fitting portion 30h of the cartridge tray 30 with a gap therebetween.

[0257] Next, as shown in FIG. 26, the exposure head 4 is slid rearward B with respect to the elevating duct 69 so that the engaging claws 55b, 55c are engaged with the elevating duct 69 in the extending direction orthogonal to the protruding direction with respect to the engaging holes 69b, 69c. The engaging claws 55b, 55c of the exposure head 4 are formed to protrude toward the elevating duct 69 and have a substantially L-shaped configuration extending in the rearward B direction which is the sliding direction of the exposure head 4. Therefore, by the sliding movement in the rearward B direction, the engaging claws 55b, 55c engage with the edges of the engaging holes 69b, 69c with the claw tips of the substantially L-shaped configuration. By this engagement, the exposure head 4 is attached to the elevating duct 69 and becomes integral with the elevating duct 69 at the position shown in FIG. 26. At the same time here, as shown in FIG. 49(b), the lower end of the positioning pin 45F of the exposure head 4 is inserted into the auxiliary fitting portion 30h of the cartridge tray 30.

[0258] In this way, after stabilizing the posture with the engaging claws 55b and 55c of the exposure head 4 penetrating the engaging holes 69b and 69c of the lifting duct 69, the exposure head 4 is slid to complete the mounting. Thereby, easy mountability of the exposure head 4 can be realized with an inexpensive configuration.

[0259] Next, the excess length of the FFC 58 connected to the exposure head 4 is stored. Here, the excess length of the FFC 58 is the length required during the operation of pulling out the exposure head 4 in the forward direction F as described above. Here, the excess length of the FFC 58 is the portion from immediately after passing through the second opening 503bK and being exposed from the cartridge tray 30 to the end of the FFC 58 connected to the FFC connector 57K.

[0260] When the exposure head 4 is attached to the lifting duct 69, the excess length of the FFC 58K is exposed in the space on the drum support member 302 of the cartridge tray 30. At this time, the other end of the FFC 58K is exposed to the outside (left side) from the first opening 503a on the left side of the main body as shown in Fig. 41(b). Therefore, by pulling out the other end of the FFC 58K to the left side (left direction L) of the main body, the FFC 58K moves to the left side (left direction L) of the main body within the FFC guide 503. For this reason, the excess length of the FFC 58K exposed in the space on the drum support member 302 is drawn into the inside of the FFC guide 503 from the second opening 503bK and is stored inside the FFC guide 503 as shown in Fig. 29(a). At this time, since one end of the FFC 58K is connected to the FFC connector 57K of the exposure head 4K, even if the FFC 58K is pulled in too much, its movement is restricted.

[0261] Next, perform the operation of removing the exposure head holding member 506. As described above, as shown in FIG. 36(d), the regulating portion 506e of the exposure head holding member 506 is engaged with the regulating portion 301g, and it is in a state where it cannot be inserted or removed. Therefore, as shown in FIG. 36(c), by lifting the exposure head holding member 506 upward, the engagement between the regulating portion 506e and the regulating portion 301g can be released, and the exposure head holding member 506 can be pulled out forward (in the forward direction F). When the above-mentioned engagement is released and the exposure head holding member 506 is pulled out in the forward direction F, the flat portion 506d of the exposure head holding member 506 is in a state of riding on the regulating portion 301g.

[0262] Furthermore, when the exposure head holding member 506 is pulled out further in the forward direction F and, as shown in FIG. 36(b), the flat portion 506d exceeds the regulating portion 301g, due to the self-weight of the exposure head holding member 506, the hole portion 506c of the exposure head holding member 506 enters and engages with the regulating portion 301g. Furthermore, as shown in FIG. 36(a), by lifting the exposure head holding member 506 upward, the engagement between the hole portion 506c and the regulating portion 301g can be released, and the exposure head holding member 506 can be pulled out further in the forward direction F. When the above-mentioned engagement is released and the exposure head holding member 506 is pulled out in the forward direction F, the inclined portion 506b is in a state of being pushed up by the regulating portion 301g. When the inclined portion 506b exceeds the regulating portion 301g and the exposure head holding member 506 is pulled out further in the forward direction F, the exposure head holding member 506 can be removed from the cartridge tray 30.

[0263] Through the above operations, the replacement operation of the exposure head 4 and the FFC 58 is completed.

[0264] In this embodiment, the exposure head holding member 506 is configured to be inserted and removed with the exposure head 4 held by the exposure head holding member 506, but the configuration is not limited to this. For example, with the exposure head holding member 506 attached to the cartridge tray 30, the exposure head 4 can be removed from the exposure head holding member 506 and a new exposure head can be placed on the exposure head holding member 506 as it is. This enables the replacement of the exposure head 4 without inserting and removing the exposure head holding member 506 in the middle.

[0265] (Effect) The effects of this embodiment will be described.

[0266] In the image forming apparatus 100 according to this embodiment, when replacing the exposure head 4, the exposure head 4 is temporarily held by the exposure head holding member 506, and the insertion and removal operation of the FFC 58 is performed. Also, the exposure head 4 is replaced by inserting and removing the exposure head holding member 506 while holding the exposure head 4. Further, the FFC 58 removed from the exposure head 4 is temporarily held by the FFC holding portions 507a and 507b of the FFC holding member 507. Also, during the replacement operation, the FFC holding member 507 is arranged to overlap with the recovery toner duct 302f which is a part of the toner conveyance path, so that the recovery toner duct 302f is blocked by the FFC holding member 507. With such a configuration, it becomes possible to stably perform the exposure head replacement operation with less burden on the operator without damaging or contaminating the exposure head and the FFC.

[0267] Also, when replacing the FFC 58, the FFC 58 is inserted and removed while covering the contact 58a of the FFC 58 with the sheet member 508, and the FFC 58 and the sheet member 508 are guided by the FFC holding member 507. With such a configuration, it becomes possible to stably perform the FFC replacement operation with less burden on the operator without damaging or contaminating the FFC 58. Further, since the sheet member 508 has a thickness between 0.15 and 0.3 mm and a tensile elastic modulus between 3500 and 4500 MPa, it is possible to stably perform the FFC replacement operation with less burden on the operator.

[0268] Further, the FFC 58 is arranged from the left side (left direction L) to the right side (right direction R) of the main body, and the contact 58a of the FFC 58 is arranged on the left side (left direction L) of the main body at the mounting position of the exposure head 4. With such a configuration, when the FFC 58 is replaced, a loop is formed so that the contact 58a is on the inner side, and thus the possibility of damaging the contact 58a can be reduced. Further, in the replacement operation of the exposure head 4, at the position where the exposure head 4 is held by the exposure head holding member 506, the contact 58a of the FFC 58 is arranged on the lower side (downward direction D) of the main body, and the protruding portion 58c is arranged on the upper side (upward direction U) of the main body. With such a configuration, an operator can insert and remove the FFC 58 with the right hand while visually observing the protruding portion 58c, so that a right-handed person can easily perform the operation.

[0269] As described above, according to the first embodiment, the exposure head 4 and the FFC 58 can be easily replaced.

[0270] 〔Second Embodiment〕 The image forming apparatus 100 in the second embodiment will be described. For the same components as those in the image forming apparatus 100 in the first embodiment, the description will be omitted by assigning the same numbers. In the present embodiment described below, the differences from the first embodiment will be described. Specifically, the configuration of the FFC, the FFC guide, the replacement tool, and the replacement of the exposure head and the FFC will be described in order.

[0271] In the present embodiment, as shown in FIG. 50, the substrate 602 is arranged on the right side of the image forming apparatus 100, and the exposure head is arranged on the left side of the substrate 602.

[0272] (Configuration of FFC and FFC Guide) Here, the configuration of the FFC658 and the FFC guide 603 will be described with reference to FIGS. 50 to 52. FIG. 50 is a perspective view showing the configuration of the exposure head 4, the FFC658, the substrate 602, and the FFC guide 603. FIG. 51(a) is a cross-sectional view taken from the front side of the image forming apparatus 100 in FIG. 50. FIG. 51(b) is an enlarged view of the vicinity of the biasing member 604 in FIG. 51(a). FIG. 52 is an enlarged view of the vicinity of the contact 658a in FIG. 51(a). However, in FIG. 52, the exposure head 4 is not shown for the sake of explanation.

[0273] (Configuration of FFC) The image forming apparatus 100 includes a plurality of FFCs 658 (658Y, 658M, 658C, 658K) that electrically connect each exposure head 4 (4Y, 4M, 4C, 4K) and the substrate 602. As described above, in this embodiment, the substrate 602 is disposed on the right side of the image forming apparatus 100, and the exposure head 4 is disposed on the left side of the substrate 602. Each FFC658 electrically connects the exposure head 4 and the substrate 602 by connecting one end to the exposure head 4 and the other end to the substrate 602.

[0274] Here, the substrate 602 is a replacement for the substrate 502 in the first embodiment and has a connector 601 having the same function as the connector 501 of the substrate 502. The connectors 601 (601Y, 601M, 601C, 601K) of the substrate 602 are connected to the other ends of the FFCs 58 (58Y, 58M, 58C, 58K) connected to each exposure head 4. The other configuration of the substrate 602 is the same as that of the substrate 502 in the first embodiment.

[0275] As shown in FIG. 50, each FFC658 connects the FFC connector 57 provided in each exposure head 4 and each connector 601 provided in the substrate 602. The FFCs 658 (658Y, 658M, 658C, 658K) are stacked and arranged.

[0276] As shown in FIG. 52, each FFC658 (658Y, 658M, 658C, 658K) has, at one end thereof, a contact 658a electrically connected to the FFC connector 57 of the exposure head 4, and a reinforcing plate 658b that is a reinforcing portion for reinforcing the contact 658a. The reinforcing plate 658b is fixed to the surface of the FFC658 opposite to the contact 658a with a double-sided tape or the like.

[0277] Each FFC658 (658Y, 658M, 658C, 658K) has, at the other end thereof, a contact (not shown) connected to each connector 601 (601Y, 601M, 601C, 601K) provided on the substrate 602.

[0278] The reinforcing plate 658b has a protruding portion 658c protruding from the surface opposite to the contact 658a. The reinforcing plate 658b is provided with the protruding portion 658c and has a shape that allows it to be pinched with a finger when inserting and removing the FFC658 from the FFC connector 57.

[0279] Here, as shown in FIGS. 51(a) and 52, in the first posture in which the exposure head 4 exposes the photosensitive drum 2, the reinforcing plate 658b and the protruding portion 658c are arranged on the left side of the contact 658a. In other words, the FFC658 is connected to the connector of the exposure head 4 held in the first posture such that the reinforcing plate 658b and the protruding portion 658c are arranged on the left side of the contact 658a in the left-right direction (second direction) of the image forming apparatus 100.

[0280] Also, as shown in FIGS. 61(a) and 61(b), in the second posture which is a holding posture for replacing the exposure head 4, the reinforcing plate 658b and the protruding portion 658c are arranged above the contact 658a. In other words, the FFC658 is connected to the connector of the exposure head 4 held in a second posture different from the first posture such that the reinforcing plate 658b and the protruding portion 658c are arranged above the contact 658a in the up-down direction (third direction) of the image forming apparatus 100.

[0281] (Configuration of the FFC Guide) The image forming apparatus 100 also includes an FFC guide 603 as a guide member that holds each FFC 658 (658Y, 658M, 658C, 658K) along the left - right direction. The FFC guide 603 is provided so as to extend in the left - right direction (second direction). The FFC guide 603 is disposed directly below the exposure head 4 inside the image forming apparatus 100. Here, the FFC guide 603 is linearly disposed in the left - right direction directly below the FFC connectors 57 (57Y, 57M, 57C, 57K) of the exposure head 4.

[0282] The FFC guide 603 is a guide member provided in the image forming apparatus 100 for regulating the position of the FFC 658. The region between one end and the other end of the FFC 658 is held inside the image forming apparatus 100 by this FFC guide 603. As shown in FIG. 51(a), the FFC guide 603 has a first opening 603a and second openings 603b (603bY, 603bM, 603bC, 603bB) through which the FFC 658 passes. The first opening 603a is disposed on the right side with respect to the second opening 603b. The first opening 603a is a first through - hole provided on the other side (right side) in the left - right direction in the FFC guide 603 and is provided on the substrate 602 side with respect to the four exposure heads 4. The second opening 603b is a second through - hole provided on one side (left side) in the left - right direction in the FFC guide 603 and is provided for each exposure head 4. The first opening 603a and the second openings 603b are provided in the FFC guide 603 and are linearly arranged in the left - right direction.

[0283] Here, although the configuration in which the first opening (first through-hole) 603a and the second opening (second through-hole) 603b are provided in the FFC guide 603 has been exemplified, the present invention is not limited thereto. For example, the first through-hole may be provided in a member other than the FFC guide 603. Further, the second through-hole may be provided in a member other than the FFC guide 603, such as the elevating duct 69 or the cartridge tray 30. In this case, the second through-hole is preferably provided on the side where the FFC holding member 607 is disposed.

[0284] In addition, the description of the biasing member 604 and the cover member 605 shown in FIGS. 51(a) and 51(b) is omitted because it is the same as the biasing member 504 and the cover member 505 shown in the first embodiment.

[0285] Next, the path of the FFC 658 from the substrate 602 to the exposure head 4 will be described.

[0286] As shown in FIG. 50, the other end of each FFC 658 is connected to each connector 601 provided on the substrate 602 disposed on the right side of the main body of the image forming apparatus 100. The FFCs 658 connected to the respective connectors 601 of the substrate 602 on the right side of the main body of the image forming apparatus 100 are laminated with the FFC 658Y, the FFC 658M, the FFC 658C, and the FFC 658K on the right side of the main body and are bent from the right side to the left side of the main body. As shown in FIG. 51(a), the laminated FFC 658 passes through the first opening 603a of the FFC guide 603 and enters the inside of the FFC guide 603. At this time, the laminated FFC 658 is biased from above to below by a biasing member 604 provided in the FFC guide 603. The FFC 658 is held so as not to move in the left-right direction by the frictional force generated by being sandwiched between the biasing member 604 and the FFC guide 603.

[0287] Note that the FFC 658 sandwiched between the biasing member 604 and the FFC guide 603 has the following stacked order in the vertical direction: from the upper side, black (B), cyan (C), magenta (M), and yellow (Y). That is, the FFC 658 sandwiched between the biasing member 604 and the FFC guide 603 is stacked in order from the upper side to the lower side in the vertical direction so as to match the arrangement order of the exposure heads 4 arranged from the right side to the left side.

[0288] The FFC 658 that has entered the interior of the FFC guide 603 is arranged to extend in the left-right direction along the FFC guide 603. When it has entered below the second opening 603bK of the FFC guide 603, only the FFC 658K is separated upward and bent and arranged to face the FFC connector 57K of the exposure head 4K. The FFC 58K is connected to the FFC connector 57K of the exposure head 4K and electrically connects the substrate 602 and the exposure head 4K. After being separated from the FFC 658K, the stacked FFCs 658 (658C, 658M, 658Y) are arranged to extend in the left-right direction from the right side of the main body toward the left side of the main body along the FFC guide 503. The subsequent path of the FFC 658 is the same as that of the black image forming unit 1K. In each of the image forming units 1C, 1M, 1Y, when it has entered below the second opening 603b, the uppermost FFC 658 is separated upward and bent and arranged to face the FFC connector 57 of the exposure head 4. The FFC 658 arranged to face the exposure head 4 is connected to the FFC connector 57 of that exposure head 4 and electrically connects the substrate 602 and the FFC connector 57.

[0289] As described above, the substrate 602 and each exposure head 4 are connected by each FFC 658. Note that in this embodiment, a configuration with four image forming units 1Y, 1M, 1C, 1K assuming a color multifunction machine is used, but a configuration with one image forming unit 1K of a monochrome multifunction machine may also be used.

[0290] (Restricting Portion of Cartridge Tray) Here, the restricting portion 302g of the cartridge tray 30 will be described with reference to FIG. 55. FIG. 55 is an enlarged perspective view of the vicinity of the restricting portion 302g of the cartridge tray 30.

[0291] As shown in FIG. 55, the cartridge tray 30 of this embodiment includes a restricting portion 302g. In the exposure head replacement operation, the restricting portion 302g abuts against a hole portion 606c and a restricting portion 606i, which are engaging portions of the exposure head holding member 606, to restrict the forward and backward movement of the exposure head holding member 606 at predetermined positions (the first position and the second position) (see FIG. 57). When moving the exposure head holding member 606 in the forward and backward directions, the restricting portion 302g restricts the movement of the exposure head holding member 606 in both the forward direction F, which is one of the forward and backward directions, and the backward direction B, which is the other direction.

[0292] Here, the restricting portion 302g includes two restricting surfaces 302g1 and 302g2.

[0293] The restricting surface 302g1 is a first restricting surface that restricts the forward movement of the exposure head holding member 606 in the forward direction F. The restricting surface 302g2 is a second restricting surface that restricts the backward movement of the exposure head holding member 606 in the backward direction B. The restricting surfaces 302g1 and 302g2 engage with the hole portion 606c of the exposure head holding member 606 at the first position where the FFC 58 is inserted into and removed from the exposure head 4, and restrict the forward and backward movement of the exposure head holding member 606. The restricting surface 302g1 engages with the restricting portion 606e of the exposure head holding member 606 at the second position where the exposure head 4 is attached to and detached from the lift duct 69, and restricts the forward movement of the exposure head holding member 606.

[0294] In this way, the restricting portion 302g restricts both the forward movement and the backward movement of the exposure head holding member 606 in the forward direction F. However, the restricting portion 302g is arranged at a position in the cartridge tray 30 where it does not restrict the forward and backward movement of the drum unit 23. Thereby, the restricting portion 302g does not prevent the forward and backward movement of the drum unit 23.

[0295] In this embodiment, a configuration is exemplified in which the regulation unit 302g is provided as a member separate from the drum support member 302. However, this is not the only case. For example, the regulation unit 302g may be directly provided on the drum support member 302. The detailed functions of the regulation unit 302g will be described later.

[0296] (Replacement tool) Next, with reference to FIGS. 53 and 54, a replacement tool used for replacing the exposure head 4 and the FFC 658 in the image forming apparatus 100 will be described. FIG. 53 is a diagram showing an exposure head holding member 606, which is one of the exposure head / FFC replacement tools. (a) is a perspective view, (b) is a top view, (c) is a cross-sectional view taken along line B-B in (b) as viewed from the left side, and (d) is a front view. FIG. 54 is a diagram showing an FFC holding member 607, which is one of the exposure head / FFC replacement tools. (a) is a perspective view, (b) is a top view, (c) is a right side view, and (d) is a rear view.

[0297] The replacement tool for the exposure head 4 and the FFC 658 is, for example, a replacement tool for removing the exposure head 4 or the FFC 658 from inside the image forming apparatus 100 and attaching a new exposure head 4 or FFC 658 when the exposure head 4 or the FFC 658 malfunctions. This replacement tool is a member used by service technicians in the market.

[0298] The replacement tool for the exposure head 4 and the FFC 658 is composed of three members: an exposure head holding member 606, an FFC holding member 607, and a sheet member 508. Any one or all of them can be attached to the housing, cover, etc. of the image forming apparatus 100 (not shown). Here, an example is given of a configuration in which the image forming apparatus 100 includes a replacement tool for the exposure head 4 and the FFC 658, but it is not limited thereto. For example, the replacement tool for the exposure head 4 and the FFC 658 may not be included in the image forming apparatus 100 but may be included with a new exposure head 4 or FFC 658 for replacement, or may be a configuration held by a service technician as a tool. Further, the replacement tool for the exposure head 4 and the FFC 658 is not limited to a configuration of three members, i.e., the exposure head holding member 606, the FFC holding member 607, and the sheet member 508, and may be any one or two members. Also, for the replacement tool for the exposure head 4 and the FFC 658, any one of the three members, i.e., the exposure head holding member 606, the FFC holding member 607, and the sheet member 508, may be included in the image forming apparatus, and the other members may be included with a new exposure head 4 or FFC 658 for replacement, or may be a configuration held by a service technician as a tool.

[0299] Also, regarding each direction of the exposure head holding member 606 and the FFC holding member 607, since it is the same as in the first embodiment, the description is omitted, and the defined forward direction F, backward direction B, right direction R, left direction L, upward direction U, and downward direction D are shown in FIGS. 53 and 54.

[0300] (Exposure head holding member) The exposure head holding member 606 is one of the replacement tools used for replacing the exposure head 4 and the FFC 658. The exposure head holding member 606 is a movable member that engages with the cartridge tray 30 during the replacement operation of the exposure head 4 and the FFC 658 and is movable in the longitudinal direction (front-rear direction) of the exposure head 4, and has a function of temporarily holding the exposure head 4.

[0301] In this embodiment, the exposure head holding member 606 is disposed on the right side in the left-right direction (on the drum unit side) via the exposure head 4 held at the exposure position. That is, the exposure head holding member 606 is disposed on the drum support member 302 of the cartridge tray 30 on the drum unit side in the left-right direction via the exposure head 4 attached to the image forming apparatus 100.

[0302] As shown in FIG. 53(c), the exposure head holding member 506 includes an inclined portion 606b and a hole portion 606c, and a flat portion 606d and a restricting portion 606e. These are in a shape for the drum support member 302 to hold the exposure head holding member 606 at the FFC insertion / removal position which is the first position and the exposure head attachment / detachment position which is the second position during the replacement operation of the exposure head 4 (see FIGS. 57(a) to 57(d)).

[0303] Note that the first position is the FFC insertion / removal position where the FFC 658 is inserted / removed with respect to the exposure head 4. The second position is the exposure head attachment / detachment position where the exposure head 4 is attached to / detached from the image forming apparatus 100.

[0304] The hole portion 606c is a first movement restricting portion that restricts the movement of the exposure head holding member 506 in the front-rear direction at the first position (FFC insertion / removal position) where a part of the exposure head 4 is exposed outside the image forming apparatus 100 in the front-rear direction.

[0305] The inclined portion 606b is inclined upward from below as it goes in the rearward direction B, and is provided immediately before the hole portion 606c in the rearward direction B. When the exposure head holding member 606 is inserted into the drum support member 302 of the cartridge tray 30 in the rearward direction B, the inclined portion 606b abuts against the restricting portion 302g of the cartridge tray 30. When the exposure head holding member 606 is further inserted in the rearward direction B, as shown in Fig. 57(a), the inclined portion 606b is pushed up by the restricting portion 302g, and the exposure head holding member 606 is lifted. As shown in Fig. 57(b), the inclined portion 606b is released from abutting against the restricting portion 302g beyond the restricting portion 302g. Then, due to the self-weight of the exposure head holding member 606, the hole portion 606c engages with the restricting portion 302g. At this time, a click feeling is generated due to the fall of the exposure head holding member 606 by its self-weight, and the operator can know that the exposure head holding member 606 has engaged with the first position. In the state where the hole portion 606c and the restricting portion 302g are engaged, the exposure head holding member 606 cannot be inserted into or removed from the cartridge tray 30, and the movement in the front-rear direction is restricted at the first position. The position where the hole portion 606c and the restricting portion 302g engage is the FFC insertion / removal position (first position) for inserting and removing the FFC 658 with respect to the FFC connector 57 of the exposure head 4. By restricting the movement of the exposure head holding member 606 in the front-rear direction in this way, it becomes possible to stabilize and simplify the FFC insertion / removal operation.

[0306] The restricting portion 606e is a second movement restricting portion that restricts the movement of the exposure head holding member 606 in the front-rear direction at a second position (exposure head attachment / detachment position) where the exposure head 4 is located inside the image forming apparatus 100 more than the first position in the front-rear direction.

[0307] The flat portion 606d is provided immediately behind the hole portion 606c and immediately in front of the restricting portion 606e in the rearward direction B. After lifting the exposure head holding member 606 to release the engagement between the hole portion 606c and the restricting portion 302g, the flat portion 606d further inserts the exposure head holding member 606 in the rearward direction B, so that, as shown in FIG. 57(c), it is in a state of riding on the restricting portion 302g. When the flat portion 606d further inserts the exposure head holding member 606 in the rearward direction B, as shown in FIG. 57(d), the contact with the restricting portion 302g is released beyond the restricting portion 302g. Then, due to the self-weight of the exposure head holding member 606, the restricting portion 606e engages with the restricting portion 302g. In a state where the restricting portion 606e and the restricting portion 302g are engaged, the exposure head holding member 606 cannot be inserted into or removed from the cartridge tray 30, and the movement in the front-rear direction is restricted at the second position. The position where the restricting portion 606e and the restricting portion 302g engage is the exposure head attachment / detachment position (second position) where the exposure head 4 is attached to and detached from the lifting duct 69. By restricting the movement of the exposure head holding member 606 in the front-rear direction in this way, it becomes possible to stabilize and simplify the exposure head attachment / detachment operation.

[0308] Further, as shown in FIG. 53(b), the exposure head holding member 606 includes a restricting portion 606f, a restricting portion 606g, a protruding portion 606j, and a guide portion 606m. These are parts for assisting the operator in operating the exposure head 4 during the replacement operation of the exposure head 4 (see FIGS. 59(a) to 59(c)).

[0309] The exposure head holding member 606 includes a regulating portion 606f on the rear side in the front-rear direction in a state of being engaged with the drum support member 302. The regulating portion 606f is a first regulating portion that regulates the position of the exposure head 4 in the front-rear direction (first direction). As shown in FIG. 58(a), the regulating portion 606f is located behind the lens array 52 of the exposure head 4 held by the elevating duct 69 and in front of the positioning pin 45B in a state where the exposure head holding member 606 is engaged with the drum support member 302. Further, the regulating portion 606f is located below the upper end of the positioning pin 45B in a state where the exposure head holding member 606 is engaged with the drum support member 302. Thereby, the regulating portion 606f abuts against the positioning pin 45B of the exposure head 4 further pulled forward in the forward direction F after the engagement with the elevating duct 69 is released, and regulates the position of the exposure head 4 in the front-rear direction.

[0310] The exposure head holding member 606 includes a regulating portion 606g on the rear side in the front-rear direction in a state of being engaged with the drum support member 302. The regulating portion 606g is a third regulating portion that regulates the position of the exposure head 4 in the vertical direction (third direction). As shown in FIG. 58(b), the regulating portion 606g is located behind the lens array 52 of the exposure head 4 held by the elevating duct 69 and in front of the positioning pin 45B in a state where the exposure head holding member 606 is engaged with the drum support member 302. Further, the regulating portion 606g is located above the upper surface (the upper surface of the housing 54) of the exposure head 4 held by the elevating duct 69 in a state where the exposure head holding member 606 is engaged with the drum support member 302. Thereby, the regulating portion 506g abuts against the exposure head 4 even when the exposure head 4 whose engagement with the elevating duct 69 is released is lifted upward in the upward direction U, and regulates the position of the exposure head 4 in the vertical direction.

[0311] The guide portion 606m is a regulating portion that regulates the locus of the positioning pin 45B of the exposure head 4 when rotating the exposure head 4, whose position is regulated by the regulating portion 606f and the regulating portion 606g, in the clockwise direction (CW direction) toward the seating surface 606h of the exposure head holding member 606. By regulating the rotation locus of the exposure head 4 with the guide portion 606m, the rotation operation of the exposure head 4 can be stably performed.

[0312] The protruding portion 606j is an engaging portion that engages with the opening 55a of the housing support member 55 of the exposure head 4 and serves as a fulcrum when rotating the exposure head 4 in the clockwise direction as described above. By engaging the exposure head 4 with the protruding portion 606j, the rotation operation of the exposure head 4 can be stably performed.

[0313] Further, as shown in FIGS. 53(b) and 53(d), the exposure head holding member 606 includes a seating surface 606h, a regulating portion 606i, a regulating portion 606k, and a regulating portion 606l. These are holding portions that stably hold the exposure head 4 during the replacement operation of the exposure head 4 (see FIG. 60).

[0314] The exposure head holding member 606 includes a seating surface 606h which is a holding part for temporarily holding the exposure head 4 removed from the elevating duct 69. As shown in Fig. 44(c), the seating surface 606h has a height difference such that it becomes lower as it progresses from one side to the other side (backward direction B) in the front-rear direction. That is, among the plurality of seating surfaces 606h provided in the front-rear direction, the height in the vertical direction of the rear seating surface 606h is lower than that of the front seating surface 606h. In addition, as shown in Fig. 44(d), the seating surface 606h has a height difference such that it becomes lower as it progresses from the other side to one side (right direction R) in the left-right direction. In other words, with respect to the exposure head 4 held by the elevating duct 69, the height in the vertical direction becomes lower as it progresses from the side closer to the exposure head 4 in the left-right direction to the side farther away. Here, for each seating surface 606h, the height in the vertical direction becomes lower from the left side to the right side in the left-right direction of the seating surface 606h. Therefore, the seating surface 606h is composed of a surface having a height difference in the front-rear direction and the left-right direction in a state where the exposure head holding member 606 is engaged with the drum support member 302. In the present embodiment, the seating surface 606h for holding the exposure head 4 is constituted by the surfaces at the tips of ribs provided at a plurality of locations in the front-rear direction, but it is not limited thereto. For example, it may be constituted by a single flat surface, and the number and position of the seating surfaces 606h may be appropriately provided as required.

[0315] The restricting portion 606i is provided on the front side in the front-rear direction and abuts against the housing 54 of the exposure head 4 after rotating in the clockwise direction as described above, and is a holding part for holding the exposure head 4. The restricting portion 606i is provided on one of the ribs provided at a plurality of locations in the front-rear direction. Here, an example of the configuration in which it is provided on the rib provided with the foremost seating surface 606h among the ribs in the front-rear direction is illustrated. The restricting portion 606i abuts against the upper surface intersecting the side surface while the seating surface 606h abuts against one side surface of the exposure head 4. That is, in the rib, the restricting portion 606i is a surface intersecting the seating surface 606h. Note that the example of the configuration in which the restricting portion 606i is provided on one of the ribs provided at a plurality of locations in the front-rear direction is illustrated, but it is not limited thereto.

[0316] The restricting portion 606k is provided on the rear side in the front-rear direction, abuts against the positioning pin 45B of the exposure head 4 after rotating in the clockwise direction as described above, and is a holding portion that holds the exposure head 4. The restricting portion 606k is a surface that intersects the seat surface 606h, which is the rearmost one among a plurality of ribs provided in the front-rear direction. The restricting portion 606k abuts against the tip of the positioning pin 45B protruding from the upper surface intersecting the side surface, while the seat surface 606h abuts against one side surface of the exposure head 4.

[0317] The exposure head holding member 606 includes a restricting portion 606l on the front side in the front-rear direction in a state of being engaged with the drum support member 302. The restricting portion 606l is a second restricting portion that restricts the position of the exposure head 4 in the left-right direction (second direction). As shown in FIG. 60, the restricting portion 606l abuts against the left end portion, which is the bottom surface portion of the exposure head 4 held on the seat surface 606h of the exposure head holding member 606, on the front side in the front-rear direction, and restricts the position of the exposure head 4 in the left-right direction.

[0318] Details of the usage procedure of the exposure head holding member 506 during the replacement operation will be described later.

[0319] (FFC Holding Member) The FFC holding member 607 is one of the replacement tools used for replacing the exposure head 4 and the FFC 658. The FFC holding member 607 has a function of engaging with the cartridge tray 30 during the replacement operation of the exposure head 4 and the FFC 658, guiding the FFC 658, and temporarily holding the FFC 658.

[0320] In this embodiment, the FFC holding member 607 is disposed on the left side in the left-right direction, which is the opposite side to the exposure head holding member 606, via the exposure head 4 held at the exposure position. That is, the FFC holding member 607 is disposed on the developing support member 301 of the cartridge tray 30 on the drum unit side in the left-right direction via the exposure head 4 mounted on the image forming apparatus 100.

[0321] As shown in Fig. 54(b), the FFC holding member 607 includes an FFC holding portion 607a and an FFC holding portion 607b that temporarily hold the FFC 658 removed from the exposure head 4. The two FFC holding portions 607b are provided to hold one surface side of the FFC 658. The FFC holding portion 607a is provided between the two FFC holding portions 607b and is provided to hold the other surface side of the FFC 658. When the exposure head 4 and the FFC 658 are being replaced, the FFC holding member 607 temporarily holds the FFC 658 by sandwiching it between the FFC holding portion 607a and the FFC holding portion 607b as shown in Fig. 65.

[0322] Further, the FFC holding member 607 includes a guide portion 607c that guides the FFC 658 from the left - right direction to the front - back direction. As shown in Figs. 54(b) to 54(d), the guide portion 607c forms a surface inclined with respect to the left - right direction and the up - down direction of the image forming apparatus 100. The inclined directions are the direction from the upper - right to the lower - left of the image forming apparatus and the direction from the upper - back to the lower - front. That is, as shown in Figs. 54(b) to 54(d), the guide portion 607c is substantially parallel to the straight line connecting the upper - right - rear to the lower - left - front of the main body. Therefore, the guide portion 607c guides the moving direction of the FFC 658 to be converted from the up - down direction and the left - right direction to the front - back direction.

[0323] Thereby, when the exposure head - FFC replacement operation is performed, it has a function of guiding the FFC 658 and the sheet member 508 to be converted from the left - right direction, which is the first moving direction, to the front - back direction, which is the second moving direction (Fig. 67).

[0324] Further, as shown in FIGS. 54(c) and 54(d), the FFC holding member 607 includes a regulating portion 607d, a regulating portion 607e, and a regulating portion 607f. The regulating portion 607d, the regulating portion 607e, and the regulating portion 607f each have a surface orthogonal to the front-rear direction, the left-right direction, and the up-down direction. The regulating portion 607d, the regulating portion 607e, and the regulating portion 607f regulate the position of the FFC holding member 607 in each direction by engaging with the developing support member 301 of the cartridge tray 30 during the exposure head - FFC replacement operation. In particular, the FFC holding member 507 has its position in the front-rear direction regulated when the regulating portion 607d engages with the developing support member 301 of the cartridge tray 30. The regulating portion 607d is provided on a part of an elastically deformable shape such as a patching claw, and by displacing it by pressing with a finger or the like, the engagement with the cartridge tray 30 is released, and the FFC holding member 607 can move in the front-rear direction (see FIGS. 63(a) and 63(b)).

[0325] Also, the bottom surface 607g of the FFC holding member 607 is disposed so as to overlap with a recovery toner duct 301h which is a part of the toner conveyance path provided in the developing support member 301 of the cartridge tray 30. At the position where the regulating portion 607d of the FFC holding member 607 described above engages with the developing support member 301 of the cartridge tray 30, the bottom surface 607g of the FFC holding member 607 is disposed so as to overlap with the recovery toner duct 301h of the cartridge tray 30.

[0326] Details of the usage procedure of the FFC holding member 607 during the replacement operation will be described later.

[0327] (Sheet member) The sheet member 508 is one of the replacement tools used for replacing the exposure head 4 and the FFC 58. As shown in FIG. 33, the sheet member 508 has a longitudinal shape. The sheet member 508 has an FFC holding portion 508a and a protruding portion 508b. Since the sheet member 508 is the same as the sheet member 508 in the first embodiment, the description thereof is omitted. The sheet member 508 can be used as a replacement tool in any of the configurations of the first embodiment and the second embodiment by inverting the front and back.

[0328] (Configuration for replacing and attaching / detaching the exposure head) With reference to FIGS. 50 to 68, the replacement of the exposure head 4 and the replacement configuration of the FFC 658 will be described in detail. However, the same content as in the first embodiment will be omitted as appropriate.

[0329] The replacement of the exposure head 4 and the FFC 658 is performed using the replacement tool described above. The replacement of the exposure head 4 and the FFC 658 is performed in the state shown in FIG. 21 where the drum unit 23 and the developing unit 24 are removed from the cartridge tray 30. Note that in the state where the photosensitive drum (drum unit) is removed from the cartridge tray 30, the exposure head 4 is configured to be manually movable from the retracted position to the exposure position. Therefore, when replacing and attaching / detaching the exposure head 4 and the FFC 658, as shown in FIG. 21, the operation is performed with the exposure head 4 manually moved to the exposure position.

[0330] The exposure head 4 and the FFC 658 are configured to be detachable from the image forming apparatus 100. The procedure for replacing the exposure head 4 and the FFC 658 will be described in detail. FIGS. 56 to 68 are diagrams showing the procedure for replacing the exposure head 4 and the FFC 658.

[0331] The operation for replacing the exposure head 4 and the operation for replacing the FFC 658 are composed of the following four procedures. Procedure 1 is to remove the old exposure head 4 from the image forming apparatus 100. Procedure 2 is to remove the old FFC 658 from the image forming apparatus 100. Procedure 3 is to attach the new FFC 658 to the image forming apparatus 100. Procedure 4 is to attach the new exposure head 4 to the image forming apparatus 100.

[0332] However, when only the exposure head 4 is replaced without replacing the FFC, steps 2 and 3 are omitted, and only steps 1 and 4 are performed. Also, when only the FFC 58 is replaced without replacing the exposure head 4, the operations of steps 1 to 4 are performed, but the following operations may not be performed in steps 1 and 4. That is, in step 1, the operation of taking out the exposure head 4 held in the second posture by the exposure head holding member 606 to the outside of the image forming apparatus 100 together with the exposure head holding member 606 may not be performed. Also, in step 4, the operation of holding the exposure head 4 in the second posture by the exposure head holding member 606 pulled out to the outside of the image forming apparatus 100 and attaching it to the image forming apparatus 100 together with the exposure head holding member 606 may not be performed.

[0333] (Step 1) Step 1 will be described. Here, an example of the replacement operation of the exposure head and the FFC in the yellow image forming unit 1Y disposed on the leftmost side in the left - right direction of the image forming apparatus 100 will be illustrated and described.

[0334] First, as shown in FIGS. 56(a) and 56(b), the exposure head holding member 606 is inserted rearward B into the drum support member 302 of the cartridge tray 30. Then, the first drum guide portion 302a and the second drum guide portion 302b of the drum support member 302 engage with the outer shape of the exposure head holding member 606. By engaging in this way, the exposure head holding member 606 is guided rearward B by the drum support member 302.

[0335] When the exposure head holding member 606 is inserted rearward B, as shown in FIG. 57(a), the inclined portion 606b of the exposure head holding member 606 abuts against the restricting portion 302g of the cartridge tray 30. When the exposure head holding member 606 is further inserted rearward B, the inclined portion 606b is pushed up by the restricting portion 302g, and the exposure head holding member 606 is pushed upward.

[0336] Insert the further exposure head holding member 606 backward in the B direction. As shown in FIG. 57(b), when the inclined portion 606b exceeds the regulating portion 302g, due to the self-weight of the exposure head holding member 606, the hole portion 606c of the exposure head holding member 606 enters and engages with the regulating portion 302g. At this time, a click feeling is generated due to the fall of the exposure head holding member 606 by its own weight, which can clearly inform the operator that it is engaged. In the state where the hole portion 606c and the regulating portion 302g are engaged, the exposure head holding member 606 cannot be inserted into or removed from the cartridge tray 30. The position where the hole portion 606c and the regulating portion 302g are engaged is the first position for inserting and removing the FFC 658 with respect to the FFC connector 57 of the exposure head 4 held by the exposure head holding member 606. With such a configuration, it becomes possible to stabilize and simplify the operation of inserting and removing the FFC 658 with respect to the exposure head 4.

[0337] Next, as shown in FIG. 57(c), by lifting the exposure head holding member 606 upward, the engagement between the hole portion 606c and the regulating portion 302g can be released, and the exposure head holding member 606 can be further inserted backward in the B direction. When the above-mentioned engagement is released and the exposure head holding member 606 is inserted backward in the B direction, the flat portion 606d of the exposure head holding member 606 is in a state of riding on the regulating portion 302g.

[0338] Insert the further exposure head holding member 606 backward in the B direction. As shown in FIG. 57(d), when the flat portion 606d exceeds the regulating portion 302g, due to the self-weight of the exposure head holding member 606, the regulating portion 606e of the exposure head holding member 606 and the regulating portion 302g are engaged. In the state where the regulating portion 606e and the regulating portion 302g are engaged, the exposure head holding member 606 cannot be inserted into or removed from the cartridge tray 30. The position where the regulating portion 606e and the regulating portion 302g are engaged is the second position for attaching and detaching the exposure head 4 to and from the lifting duct 69. With such a configuration, the exposure head holding member 606 is held by the drum support member 302 at the first position for inserting and removing the FFC 658 and the second position for attaching and detaching the exposure head 4, and it becomes possible to stabilize and simplify the exposure head attachment operation.

[0339] Next, the operation of placing the exposure head 4 on the exposure head holding member 606 is performed. Note that since the engagement configuration between the exposure head 4 and the elevating duct 69 is the same as that in the aforementioned first embodiment, the description thereof is omitted.

[0340] The exposure head 4 is pulled out in the forward direction F to disengage it from the elevating duct 69 (see FIG. 25). When the exposure head 4 is further pulled out in the forward direction F, as shown in FIG. 58(a), the positioning pin 45B of the exposure head 4 abuts against the restricting portion 606f of the exposure head holding member 606 held at the second position, and the movement of the exposure head 4 in the forward direction F is restricted. At this time, as shown in FIG. 58(b), there is a restricting portion 606g of the exposure head holding member 606 above the exposure head 4. Therefore, even if the exposure head 4 is lifted upward in the upward direction U, the housing 54 abuts against the restricting portion 606g, and the movement of the exposure head 4 in the upward direction U is also restricted, and the exposure head 4 remains in a predetermined position.

[0341] Next, as shown in FIGS. 59(a), 59(b), and 59(c) in this order, while rotating the exposure head 4 in the clockwise direction (CW direction) when viewed from the front side, it is placed on and set on the seating surface 606h of the exposure head holding member 606. At this time, the guide portion 606m shown in FIG. 58(a) restricts the rotation locus of the positioning pin 45B, and the protruding portion 606j shown in FIG. 60 engages with the opening 55a of the housing support member 55 to serve as a rotation fulcrum. Thereby, the exposure head 4 can be rotated stably. Further, as shown in FIG. 60, the exposure head 4 after being rotated as described above is stably held by the exposure head holding member 606 when the restricting portion 606i abuts against the housing 54, the restricting portion 606k abuts against the positioning pin 45B, and the restricting portion 606l abuts against the bottom surface portion 55D of the housing support member 55.

[0342] Here, as shown in FIGS. 53(c) and 53(d), the seating surface 606h of the exposure head holding member 606 is a surface having height differences in the left-right direction and the front-rear direction. That is, the rear seating surface 606h in the front-rear direction is lower in the vertical direction than the front seating surface 606h in the front-rear direction, and each seating surface 606h is lower from the right side to the left side in the left-right direction. As a result, the exposure head 4 rotated in the clockwise direction when viewed from the front side of the apparatus is biased by its own weight onto the seating surface 606h of the exposure head holding member 606 and is uniquely held on the exposure head holding member 606 as shown in FIG. 61(a). Further, as shown in FIG. 53(c), in the front-rear direction, the front seating surface 606h on the operator side is higher than the rear seating surface 606h, enabling the operator to easily perform the above-described rotation operation.

[0343] Note that the exposure head 4 rotated in the clockwise direction and set on the seating surface 606h of the exposure head holding member 606 is held by the exposure head holding member 606 in the second posture shown in FIGS. 60 and 61(a). The second posture is a posture different from the above-described first posture and is a holding posture for replacing the exposure head 4. Further, in the second posture, the LED chip 53 is disposed on the right in the left-right direction and the FFC connector 57 is disposed on the left. Further, as shown in FIGS. 61(a) and 61(b), the FFC 658 is connected to the FFC connector 57 of the exposure head 4 held in the second posture such that the contact 658a is disposed on the lower side and the reinforcing plate 658b and the protruding portion 658c are disposed on the upper side of the contact 658a in the vertical direction.

[0344] Next, in order to take out the exposure head 4 held by the exposure head holding member 606 in the second posture, excess length processing of the FFC 658 connected to the exposure head 4 is performed. One end of the FFC 658 is connected to the FFC connector 57 of the exposure head 4, and the other end is connected to the connector 601 of the substrate 602 disposed on the right side of the main body of the image forming apparatus 100. As shown in FIG. 62(a), in the yellow image forming unit 1Y, first, the other end of the FFC 658Y is removed from the connector 601Y of the substrate 602, the biasing member 604 is removed from the FFC guide 603, and the FFC 658Y is made movable. When the FFC 658Y is pushed from the right side to the left side (left direction L) in the left-right direction, as shown in FIG. 62(b), the FFC 658Y moves to the left side (left direction L) within the FFC guide 603, and the moved FFC 658Y passes through the second opening 603bY of the FFC guide 603. Since one end of the FFC 658Y is connected to the FFC connector 57Y and its movement is restricted, the FFC 658Y that has passed through the second opening 603bY is fed out into the space on the developing support member 301 of the cartridge tray 30, as shown in FIG. 62(c). Then, the FFC 658Y fed out into the space on the developing support member 301 forms a bent portion 658d that is more curved than before feeding between the second opening 603bY and the FFC connector 57Y. At this time, the total length (excess length) Ld of the bent portion 658d is the length required for the operation of pulling out the exposure head 4 in the forward direction F. The bent portion 658d formed here is the portion from the portion immediately after passing through the second opening 603bY and exposed from the cartridge tray 30 to the end of the FFC 658 connected to the FFC connector 57Y.

[0345] Next, as shown in FIG. 63(a), the FFC holding member 607 is inserted backward B into the developing support member 301 of the cartridge tray 30. At this time, as shown in FIG. 63(b), the guide portion 607c of the FFC holding member 607 is inserted so as to pass through the inside of the bent portion 658d of the FFC 658Y. In other words, the guide portion 607c of the FFC holding member 607 is inside the bent portion 658d of the FFC 658Y and penetrates between one end and the other end of the bent portion 658d. Here, one end of the bent portion 658d is the end of the FFC 658 connected to the FFC connector 57Y. Further, the other end of the bent portion 658d is located below the one end and is the portion immediately after passing through the second opening 603bY and exposing from the cartridge tray 30. Then, the restricting portions 607e, 607f (see FIGS. 54(c) and 54(d)) of the FFC holding member 607 inserted backward B engage with the developing support member 301 and are guided to restrict the left-right and up-down positions of the FFC holding member 607, respectively. Further, the restricting portion 607d of the FFC holding member 607 engages with an engaging portion (not shown) provided on the developing support member 301 to restrict the front-rear position of the FFC holding member 607. At this time, the bottom surface 607g of the FFC holding member 607 is disposed so as to overlap with the recovered toner duct 301h which is a part of the toner conveyance path. Thereby, the recovered toner duct 301h of the cartridge tray 30 is blocked by the FFC holding member 607.

[0346] Next, perform the operation of removing the FFC658 from the FFC connector 57 of the exposure head 4. As described above, as shown in FIG. 57(d), the exposure head holding member 606 has the regulating portion 606e engaged with the regulating portion 302g, and the movement in the front-rear direction is restricted at the exposure head attachment / detachment position (second position), and it is in a state where it cannot be inserted or removed. Therefore, as shown in FIG. 57(c), by lifting the exposure head holding member 606 upward, the engagement between the regulating portion 606e and the regulating portion 302g is released, and the exposure head holding member 606 is pulled out in the forward direction F. At this time, the flat portion 606d is in a state of riding on the regulating portion 302g. While pulling out the exposure head holding member 606 from the cartridge tray 30 in the forward direction F as it is, when the flat portion 606d exceeds the regulating portion 302g as shown in FIG. 57(b), the hole portion 606c enters and engages with the regulating portion 302g due to the self-weight of the exposure head holding member 606. As described above, the position where the hole portion 606c engages with the regulating portion 302g is the FFC insertion / removal position (first position) for inserting and removing the FFC658 with respect to the FFC connector 57 of the exposure head 4, and it is in the state shown in FIGS. 64(a) and 64(b).

[0347] At the FFC insertion / removal position shown in FIGS. 64(a) and 64(b), the exposure head holding member 606 is restricted from moving in the front-rear direction due to the engagement between the hole portion 606c and the regulating portion 302g, and a part of the exposure head 4 is in a state of being exposed outside the image forming apparatus 100 in the front-rear direction. More specifically, at the FFC insertion / removal position, the exposure head 4 held by the exposure head holding member 606 is in a state where the FFC connector 57 is exposed outside from the front side plate 100F of the image forming apparatus 100.

[0348] At this FFC insertion / removal position, the operator holds the protruding portion 658c provided on the FFC 658 and pulls out the FFC 658 from the FFC connector 57 in the left direction L. As described above, the reinforcing plate 658b and the protruding portion 658c are arranged above (in the upward direction U) the contact point 658a, facilitating the operation of pulling out the FFC 658 in the left direction L. Also, as shown in FIG. 64(b), since the exposure head 4 held by the exposure head holding member 606 has the FFC connector 57 pulled out to the front side of the front side plate 100F, the visibility is improved and the FFC insertion / removal operation becomes easier. The FFC 658 removed from the exposure head 4 is sandwiched and held between the FFC holding portions 607a and 607b of the FFC holding member 607 as shown in FIG. 65. With the above configuration, as described above, it becomes possible to stabilize and simplify the FFC insertion / removal operation.

[0349] Next, an operation of removing the exposure head 4 from the image forming apparatus 100 is performed. As shown in FIG. 57(a), by lifting the exposure head holding member 606 upward, the engagement between the hole portion 606c and the regulating portion 302g can be released, and the exposure head holding member 606 can be further pulled out in the forward direction F. At this time, the inclined portion 606b of the exposure head holding member 606 is in a state of being pushed up by the regulating portion 302g. By pulling out the exposure head holding member 606 in the forward direction F as it is, the exposure head 4 can be removed from the image forming apparatus 100 together with the exposure head holding member 606 as shown in FIG. 66. With the above configuration, as described above, it becomes possible to stabilize and simplify the operation of removing the exposure head.

[0350] (Procedure 2) Procedure 2 will be described.

[0351] When Procedure 1 is completed, as shown in FIG. 62(b), the FFC658Y is held by the FFC holding member 607, and one end thereof is exposed to the outside (front side) from the front side plate 100F of the image forming apparatus 100. Further, the FFC658Y with one end held is folded back along the guide portion 607c in a direction intersecting the rear direction B as shown in FIG. 64(a), passes through the second opening 603bY as shown in FIG. 62(b), and passes through the inside of the FFC guide 603 in the left-right direction. Further, the other end of the FFC658Y penetrates through the first opening 603a and is exposed outside the FFC guide 603.

[0352] Similar to Example 1, remove one end of the FFC658Y from the FFC holders 607a and 607b. Attach and hold one end of the removed FFC658 to the FFC holder 508a of the sheet member 508 as shown in FIG. 67. Here, the FFC658 is sandwiched and held by the three arms 508aa, 508ab, 508ac and the base 508c of the FFC holder 508a. Further, the arm 508ac closest to the tip of the FFC658 is configured to hold the reinforcing plate 658b so that the FFC658 and the sheet member 508 do not separate as shown in FIG. 67(c). Specifically, the arm 508ac closest to the tip of the FFC658 enters between the protruding portion 658c and the FFC658, the arm 508ac is caught between the reinforcing plate 658b and the FFC658, and the reinforcing plate 658b is held so that the FFC658 and the sheet member 508 do not separate. With this configuration, the FFC658 and the sheet member 508 can move integrally.

[0353] Further, as shown in FIG. 67(c), the sheet member 508 holds the FFC658 in a state where the contact 658a of the FFC658 abuts on the base 508c of the sheet member 508. Thereby, the sheet member 508 protects the contact 658a so that the contact 658a of the FFC658 does not slide against other members.

[0354] Here, when the FFC658Y in the state shown in FIG. 62(b) is pulled out in the right direction R, the FFC658Y and the sheet member 508 are pulled into the backward direction B shown in FIG. 67(a). The FFC658 and the sheet member 508 are folded back by the guide portion 607c, pass through the second opening 603bY of the FFC guide 603, pass through the inside of the FFC guide 603, pass through the first opening 603a, and are pulled out from the right side of the main body as shown in FIG. 68(a). At this time, the FFC658Y is held by the sheet member 508 so as to pass through the FFC guide 603 as shown in FIG. 68(b). In other words, the FFC holding portion 508a of the sheet member 508 and the end portion of the FFC58K are in a state of passing through the inside of the FFC guide 603 and being exposed to the outside from the first opening 603a. Further, as shown in FIG. 68(c), the protruding portion 608b of the sheet member 508 is in a state of being exposed to the front side of the image forming apparatus 100. Then, the FFC658Y is removed from the FFC holding portion 508a of the sheet member 508. By the above operations, the FFC658 before replacement can be removed from the image forming apparatus 100, and at the same time, the sheet member 608 can be disposed in the image forming apparatus 100.

[0355] Note that the thickness and tensile elastic modulus of the sheet member 508 are the same as those in the first embodiment, and thus the description thereof is omitted.

[0356] Also, when the operator accidentally pulls the FFC658Y and the sheet member 508 too far in the right direction (right direction R) of the main body, the description is omitted because it is the same as that in the first embodiment except that the pulling direction is reversed.

[0357] (Procedure 3) Procedure 3 will be described.

[0358] When the procedure 2 is completed, the sheet member 608 passes through the first opening 603a, and the FFC holding part 608a is exposed from the left side of the main body. As shown in Fig. 68(a), a new FFC 658 is attached to the FFC holding part 508a of this sheet member 508. Thereby, the FFC 658 and the sheet member 508 are integrated and movable. Here, when the sheet member 508 in the state shown in Fig. 68(c) is pulled out to the front side (forward direction F) of the main body, the FFC 658 and the sheet member 508 are pulled in the left direction L shown in Fig. 68(a). The FFC 658 and the sheet member 508 pass through the first opening 603a of the FFC guide 603 and pass through the inside of the FFC guide 603, and are folded back while forming a loop with the contact 658a side inside by the guide part 607c of the FFC holding member 607, and are pulled out from the front side of the main body as shown in Fig. 67(a). At this time, the guide part 607c of the FFC holding member 607 guides the moving direction of the FFC 658 and the sheet member 508 to be converted from the left-right direction (left direction L), which is the first moving direction, to the front-back direction (forward direction F), which is the second moving direction. Further, the guide part 607c forms a surface inclined with respect to the left-right direction and the up-down direction of the image forming apparatus 100, and the inclined directions are the direction from the upper right to the lower left of the image forming apparatus and the direction from the upper back to the lower front. Thereby, it is possible to smoothly convert the moving direction (Fig. 68(c)).

[0359] The FFC 658Y is held so as to pass through the FFC guide 603 as shown in Fig. 51(a). Further, as shown in Fig. 62(b), the other end of the FFC 658Y is exposed on the right side of the image forming apparatus 100, and as shown in Fig. 67(a), one end of the FFC 658Y is exposed on the front side of the image forming apparatus 100. Then, the FFC 658 is removed from the FFC holding part 508a of the sheet member 508, and the removed FFC 658 is sandwiched and held between the FFC holding part 607a and the FFC holding part 607b of the FFC holding member 607 as shown in Fig. 65. By the above operations, the replaced FFC 658 can be attached to the image forming apparatus 100, and at the same time, the sheet member 508 can be taken out from the image forming apparatus 100.

[0360] (Procedure 4) Procedure 4 will be described.

[0361] First, as shown in FIG. 60, the exposure head 4 is set on the exposure head holding member 606. The exposure head 4 is stably held on the exposure head holding member 606 by the contact of the regulating portion 606i with the housing 54, the contact of the regulating portion 606k with the positioning pin 45B, and the contact of the regulating portion 606l with the bottom surface portion 55D of the housing support member 55.

[0362] Next, in the same manner as in Procedure 1, as shown in FIGS. 56(a) and 56(b), the exposure head holding member 606 is inserted rearward in the B direction into the drum support member 302 of the cartridge tray 30. Then, the exposure head holding member 606 engages with the drum support member 302 and is guided rearward in the B direction by the drum support member 302.

[0363] When the exposure head holding member 606 is inserted rearward in the B direction, as shown in FIG. 57(a), the inclined portion 606b of the exposure head holding member 606 contacts the regulating portion 302g of the cartridge tray 30, and the exposure head holding member 606 is pushed upward. As shown in FIG. 57(b), when the inclined portion 606b passes over the regulating portion 302g, the hole portion 606c of the exposure head holding member 606 engages with the regulating portion 302g entering therein due to the self-weight of the exposure head holding member 606. The position where the hole portion 606c and the regulating portion 302g engage is the first position for inserting and removing the FFC 658 with respect to the FFC connector 57 of the exposure head 4 held by the exposure head holding member 606, and is in the state shown in FIG. 65.

[0364] Here, the operator holds the protrusion 58c provided on the FFC658, removes the FFC658 from the FFC holding member 607, and inserts it in the right direction R with respect to the FFC connector 57 of the exposure head 4 held in the second posture as shown in FIG. 64(a). As described above, the protrusion 658c is arranged upward (in the upward direction U), facilitating the insertion operation. Also, as shown in FIG. 64(b), since the end portions of the FFC connector 57 of the exposure head 4 and the FFC658 are pulled out in front of the front side plate 100F of the image forming apparatus 100, the visibility is improved and the operation becomes easier. By adopting the above configuration, as described above, it becomes possible to stabilize and simplify the FFC insertion / removal operation.

[0365] Next, as shown in FIG. 57(c), by lifting the exposure head holding member 606 upward, the engagement between the hole portion 606c and the regulating portion 302g can be released, and the exposure head holding member 606 can be further inserted in the rearward direction B. When the above engagement is released and the exposure head holding member 606 is inserted in the rearward direction B, the flat portion 606d of the exposure head holding member 606 is in a state of riding on the regulating portion 302g.

[0366] When the exposure head holding member 606 is further inserted in the rearward direction B and the flat portion 606d exceeds the regulating portion 302g as shown in FIG. 57(d), the regulating portion 606e of the exposure head holding member 606 and the regulating portion 302g engage with each other due to the self-weight of the exposure head holding member 606. In the state where the regulating portion 606e and the regulating portion 302g are engaged, the exposure head holding member 606 cannot be inserted / removed with respect to the cartridge tray 30. As described above, the position where the regulating portion 606e and the regulating portion 302g engage is the second position for attaching / detaching the exposure head 4 to / from the elevating duct 69. After arranging the exposure head holding member 606 at the second position, the engagement with the cartridge tray 30 is released by elastically deforming the regulating portion 607d of the FFC holding member 607 or the like, and the FFC holding member 607 is pulled out in the forward direction F and removed from the image forming apparatus 100.

[0367] Next, the operation of placing the exposure head 4 on the lifting duct 69 is performed. Note that the operation of placing the exposure head 4 on the lifting duct 69 is the same as that in the first embodiment, and thus the description thereof is omitted.

[0368] Next, the excess length of the FFC 658 connected to the exposure head 4 is stored. Here, the excess length of the FFC 658 is the length required during the operation of pulling out the exposure head 4 in the forward direction F as described above. Here, the excess length of the FFC 658 is the portion from immediately after passing through the second opening 603bY and being exposed from the cartridge tray 30 to the end of the FFC 658 connected to the FFC connector 57Y.

[0369] With the exposure head 4 attached to the lifting duct 69, the excess length of the FFC 658Y is exposed in the space on the development support member 301 of the cartridge tray 30. At this time, the other end of the FFC 658Y is exposed to the outside (right side) from the first opening 603a on the left side of the main body as shown in FIG. 62(b). Therefore, by pulling out the other end of the FFC 658Y to the right side (right direction R) of the main body, the FFC 658Y moves to the right side (right direction R) of the main body within the FFC guide 603. For this reason, the excess length of the FFC 658Y exposed in the space on the development support member 301 is drawn into the inside of the FFC guide 603 from the second opening 603bY and is stored inside the FFC guide 603 as shown in FIG. 51(a). At this time, since one end of the FFC 658Y is connected to the FFC connector 57Y of the exposure head 4Y, even if the FFC 658Y is pulled in too much, its movement is restricted.

[0370] Next, perform the operation of removing the exposure head holding member 606. As described above, the exposure head holding member 606 is in a state where the restricting portion 606e and the restricting portion 302g are engaged as shown in FIG. 57(d) and cannot be inserted or removed. Therefore, as shown in FIG. 57(c), by lifting the exposure head holding member 606 upward, the engagement between the restricting portion 606e and the restricting portion 302g can be released, and the exposure head holding member 606 can be pulled out forward (in the forward direction F). When the above-described engagement is released and the exposure head holding member 606 is pulled out in the forward direction F, the flat portion 606d of the exposure head holding member 606 is in a state of riding on the restricting portion 302g.

[0371] Furthermore, when the exposure head holding member 606 is pulled out further in the forward direction F and the flat portion 606d exceeds the restricting portion 302g as shown in FIG. 57(b), the hole portion 606c of the exposure head holding member 606 enters and engages with the restricting portion 302g due to the self-weight of the exposure head holding member 606. Furthermore, as shown in FIG. 57(a), by lifting the exposure head holding member 606 upward, the engagement between the hole portion 606c and the restricting portion 302g can be released, and the exposure head holding member 606 can be pulled out further in the forward direction F. When the above-described engagement is released and the exposure head holding member 606 is pulled out in the forward direction F, the inclined portion 606b is in a state of being pushed up by the restricting portion 302g. When the inclined portion 606b exceeds the restricting portion 302g and the exposure head holding member 606 is pulled out further in the forward direction F, the exposure head holding member 606 can be removed from the cartridge tray 30.

[0372] Through the above operations, the replacement work of the exposure head 4 and the FFC 658 is completed.

[0373] In addition, in this embodiment, the exposure head holding member 606 is inserted and removed with the exposure head 4 held by the exposure head holding member 606, but the configuration is not limited to this. For example, with the exposure head holding member 606 attached to the cartridge tray 30, the exposure head 4 can be removed from the exposure head holding member 606 and a new exposure head can be placed on the exposure head holding member 606 as it is. This enables the replacement of the exposure head 4 without inserting and removing the exposure head holding member 606 midway.

[0374] (Effect) The effects of this embodiment will be described.

[0375] In the image forming apparatus 100 according to this embodiment, when replacing the exposure head 4, the exposure head 4 is temporarily held by the exposure head holding member 606, and the insertion and removal operation of the FFC 658 is performed. Further, the exposure head 4 is replaced by inserting and removing the exposure head holding member 606 while holding the exposure head 4. Also, the FFC 658 removed from the exposure head 4 is temporarily held by the FFC holding portions 607a and 607b of the FFC holding member 607. Further, during the replacement operation, the FFC holding member 607 is arranged so as to overlap with the recovered toner duct 301h which is a part of the toner conveyance path, thereby closing the recovered toner duct 301h with the FFC holding member 607. With such a configuration, it is possible to stably perform the exposure head replacement operation with less burden on the operator without damaging or contaminating the exposure head and the FFC.

[0376] Also, when replacing the FFC 658, the FFC 658 is inserted and removed while covering the contact 658a of the FFC 658 with the sheet member 508, and the FFC 658 and the sheet member 508 are guided by the FFC holding member 607. With such a configuration, it is possible to stably perform the FFC replacement operation with less burden on the operator without damaging or contaminating the FFC 658.

[0377] Further, the FFC 658 is arranged from the right side (right direction R) to the left side (left direction L) of the main body, and the contact 658a of the FFC 658 is arranged on the right side (right direction R) of the main body at the mounting position of the exposure head 4. By adopting such a configuration, a loop is formed so that the contact 658a is on the inner side when the FFC 658 is replaced, so that the possibility of damaging the contact 658a can be reduced. Further, in the operation of replacing the exposure head 4, at the position where the exposure head 4 is held by the exposure head holding member 606, the contact 658a of the FFC 658 is arranged on the lower side (downward direction D) of the main body, and the protruding portion 658c is arranged on the upper side (upward direction U) of the main body. By adopting such a configuration, the operator can perform the insertion and removal operation of the FFC 658 while visually observing the protruding portion 658c, so that the configuration is easy to operate.

[0378] Further, the FFC 658 is arranged from the right side (right direction R) to the left side (left direction L) of the main body, and the contact of the FFC 658 is arranged on the right side (right direction R) of the main body at the mounting position of the exposure head 4. By adopting such a configuration, a loop is formed so that the contact is on the inner side when the FFC 658 is replaced, so that the possibility of damaging the contact can be reduced. Further, in the operation of replacing the exposure head, at the position where the exposure head 4 is held by the exposure head holding member 606, the contact of the FFC 658 is arranged on the lower side (downward direction D) of the main body, and the protruding portion is arranged on the upper side (upward direction U) of the main body. By adopting such a configuration, the operator can perform the insertion and removal operation of the FFC 658 while visually observing the protruding portion, so that the configuration is easy to operate.

[0379] As described above, according to the second embodiment, the exposure head 4 and the FFC 658 can be easily replaced.

[0380] 〔Other Embodiments〕 The configuration according to the present invention is not limited to the embodiments described above.

[0381] In the foregoing embodiments, a tandem-type and intermediate transfer-type four-color full-color printer has been exemplified and described. However, for example, a direct transfer method may be used in which the toner image is transferred from the photosensitive drum 2 to the recording paper P without using the intermediate transfer belt 9. Furthermore, a single-color monochrome printer or a full-color printer with five or more colors using special toner may be used. In that case, a configuration in which exposure heads 4 corresponding to the number of colors are provided may be used.

[0382] Furthermore, in the foregoing embodiment, the opening 61 of the duct unit 60 is connected to the opening 64 formed by the cartridge tray 30 and the elevating duct 69, but the present invention is not limited thereto. For example, the opening 64 may be removed, an opening may be provided in the elevating duct 69, and the opening of the duct unit 60 may be directly connected.

[0383] Furthermore, in the foregoing embodiment, a configuration in which the cooling duct 75 (see FIG. 18) is formed between the duct unit 60 and the cartridge tray 30 or the elevating duct 69 has been exemplified, but it is not necessarily formed by the duct unit 60. In that case, the cooling duct 75 may be formed only by the cartridge tray 30 or the elevating duct 69.

[0384] Also, the vertical direction of the units and components has been described according to the arrangement of each unit in the cross-sectional view of the image forming apparatus 100 shown in FIG. 2. However, a unit arrangement may be used in which the photosensitive drum 2 is disposed above the intermediate transfer belt 9 and the exposure head 4 is disposed further above the photosensitive drum 2, such as an upper surface exposure method in which exposure is performed from substantially above the photosensitive drum 2. In that case, the up and down directions in the description of the embodiment are all reversed.

[0385] In the foregoing embodiments, a configuration in which the engaging claws 55b and 55c are provided on the housing support member 55 constituting the exposure head 4 has been exemplified, but engaging claws may be provided on the components on the side of the image forming apparatus 100. In that case, an L-shaped engaging claw may be provided on the elevating duct 69, and an engaging hole that engages with the engaging claw may be provided in the housing support member 55.

[0386] Furthermore, in the above-described embodiment, the configuration in which the housing support member 55 constituting the exposure head 4 is provided with the recess 55f was exemplified. However, a recess may be provided in the component on the image forming apparatus 100 side. In that case, a recess may be provided in the elevating duct 69, and a convex portion engaging with the recess may be provided in the housing support member 55.

[0387] Also, in the above-described embodiment, the sliding operation for mounting the exposure head 4 was performed from the front to the rear of the image forming apparatus 100. However, a configuration in which it is slid from the rear to the front may be employed. In that case, the shapes of the engaging claw and the engaging hole may be reversed in the front-rear direction.

[0388] Also, in the above-described embodiment, the positioning in the axis direction of the photosensitive drum 2 of the exposure head 4 and the grounding connection were performed with the front positioning pin 45F. However, they may be performed with the rear positioning pin 45B. Furthermore, in the grounding connection, they may be performed with both the front and rear positioning pins 45F and 45B.

Explanation of Reference Numerals

[0389] 1, 1Y, 1M, 1C, 1K... Image forming unit 2, 2Y, 2M, 2C, 2K... Photosensitive drum (photoconductor) 4, 4Y, 4M, 4C, 4K... Exposure head 5, 5Y, 5M, 5C, 5K... Developing sleeve (developer carrier) 23, 23Y, 23M, 23C, 23K... Drum unit (photoconductor unit) 24, 24Y, 24M, 24C, 24K... Developing unit 30... Cartridge tray (support member) 45F, 45B... Positioning pin 50... Substrate 51... LED (light emitting element) 52... Lens array 53, 53-1~53-29... LED chip 54... Housing 55... Housing support member 55b, 55c... Engaging claw 57, 57Y, 57M, 57C, 57K … FFC Connector 58, 58Y, 58M, 58C, 58K, 658, 658Y, 658M, 658C, 658K … FFC (Flexible Flat Cable) 58a, 658a … Contact Point 58b, 658b … Reinforcing Plate (Reinforcing Portion) 58c, 658c … Protrusion 58d, 658d … Bend 60 … Duct Unit 69 … Elevating Duct (Exposure Support Member) 69b, 69c … Engaging Hole 70, 71, 72 … Seal 100 … Image Forming Apparatus 100B … Rear Side Plate 100F … Front Side Plate 301 … Developing Support Member 301a, 301b … Developing Guide Portion 301c … Developing Bottom Surface 301d … Opposing Portion 301e … Partition Portion 301f … Developing Guide Portion 301g … Regulation Portion 301g1, 301g2 … Regulation Surface 301h … Toner Recovery Duct 302 … Drum Support Member 302a, 302b … Drum Guide Portion 302c … Drum Bottom Surface 302f … Toner Recovery Duct 302g … Regulation Portion 302g1, 302g2 … Regulation Surface 501 … Connector 501, 501Y, 501M, 501C, 501K, 601, 601Y, 601M, 601C, 601K … Connector 502, 602 … Substrate (Control Substrate) 503, 603 … FFC Guide (Guide Member) 503a, 603a … First Opening (First Through Hole) 503b, 603b … Second Opening (Second Through Hole) 504, 604... Biasing member 505, 605... Cover member 506, 606... Exposure head holding member (replacement tool) 506a... Engaging portion 506b, 606b... Inclined portion 506c, 606c... Hole portion (first movement restricting portion) 506d, 606d... Flat portion 506e, 606e... Restricting portion (second movement restricting portion) 506f, 606f... Restricting portion (first restricting portion) 506g, 606g... Restricting portion (third restricting portion) 506h, 606h... Seat surface (holding portion) 506i, 606i... Restricting portion 506j, 606j... Protruding portion 506k, 606k... Restricting portion 506l, 606l... Restricting portion (second restricting portion) 506m, 606m... Guide portion 507, 607... FFC holding member (replacement tool) 507a, 507b... FFC holding portion 507c... Guide portion 507d, 507e, 507f... Restricting portion 507g, 607g... Bottom surface 508... Sheet member (replacement tool) 508a... FFC holding portion (cable holding portion) 508aa, 508ab, 508ac... Arm portion 508b... Protruding portion 508c... Base portion

Claims

1. A photoreceptor, an exposure head having a connector, having a longitudinal shape in the axial direction of the photoreceptor, and exposing the photoreceptor, a control board, a flexible flat cable electrically connecting the connector and the control board, a guide member provided to extend in the left - right direction of the image forming apparatus orthogonal to the axial direction and the vertical direction, and holding the flexible flat cable along the left - right direction, An exchange tool used for exchanging the flexible flat cable in an image forming apparatus comprising: The exchange tool has a sheet member having a longitudinal shape, The sheet member, has a cable holding portion for holding the flexible flat cable at one end side in the longitudinal direction, The length from the cable holding portion to the other end in the longitudinal direction is such that the other end is exposed from a first through - hole arranged on one side in the left - right direction and the cable holding portion is exposed from a second through - hole arranged on the other side in the left - right direction via the guide member, An exchange tool characterized by the above.

2. The cable holding portion of the sheet member holds a contact electrically connected to the connector of the flexible flat cable. The exchange tool according to claim 1, characterized by the above.

3. The flexible flat cable has a reinforcing portion for reinforcing the contact, The cable holding portion of the sheet member holds the reinforcing portion. The exchange tool according to claim 2, characterized by the above.

4. The cable holding portion of the sheet member is composed of a plurality of arm portions that sandwich the flexible flat cable between the base portion, and one of the plurality of arm portions penetrates between the reinforcing portion and the flexible flat cable to sandwich the flexible flat cable between the base portion. The exchange tool according to claim 3, characterized by the above.

5. The sheet member has a first region wider in the axial direction than the second through - hole and a second region narrower in width. The exchange tool according to claim 1, characterized by the above.

6. The image forming apparatus includes a plurality of photoreceptors, The sheet member is longer than three times the distance between the plurality of photoreceptors. The exchange tool according to claim 1, characterized by the above.

7. The sheet member holds the flexible flat cable in a state of being in contact with the contact of the flexible flat cable. The replacement tool according to claim 2, characterized in that...

8. The sheet member has a thickness of 0.15 to 0.3 [mm], a tensile elastic modulus of 3500 to 4500 [MPa], and is made of resin. The replacement tool according to claim 1, characterized in that...

9. The replacement tool has an FFC holding member for holding the flexible flat cable. The FFC holding member is disposed on one side or the other side in the left - right direction via an exposure head held at the exposure position. The replacement tool according to claim 1, characterized in that...

10. The replacement tool has an exposure head holding member for holding the exposure head. The exposure head holding member is disposed on the side opposite to the FFC holding member via an exposure head held at the exposure position. The replacement tool according to claim 9, characterized in that...

11. A photoreceptor; An exposure head having a connector, having a shape elongated in the axial direction of the photoreceptor, and exposing the photoreceptor; A control board; A flexible flat cable electrically connecting the connector and the control board; A guide member provided to extend in the left - right direction of the image forming apparatus orthogonal to the axial direction and the vertical direction, and holding the flexible flat cable along the left - right direction; A replacement tool used for replacing the flexible flat cable, comprising: The replacement tool has a sheet member having an elongated shape. The sheet member... Has a cable holding portion for holding the flexible flat cable at one end side in the longitudinal direction. The length from the cable holding portion to the other end in the longitudinal direction is such that the other end is exposed from a first through - hole disposed on one side in the left - right direction via the guide member, and the cable holding portion is exposed from a second through - hole disposed on the other side in the left - right direction. An image forming apparatus, characterized in that...

12. A plurality of photoreceptors; Exposure heads having connectors, having shapes elongated in the axial direction of the photoreceptors, and exposing the plurality of photoreceptors respectively; A control board; A plurality of flexible flat cables electrically connecting the connectors of the respective exposure heads and the control board respectively; A guide member provided to extend in the left - right direction of the image forming apparatus orthogonal to the axial direction and the vertical direction, and holding the flexible flat cable along the left - right direction; An exchange tool used for exchanging the flexible flat cable, and the exchange tool has a sheet member having a longitudinal shape, the sheet member, has a cable holding portion for holding the flexible flat cable on one end side in the longitudinal direction, the length from the cable holding portion to the other end in the longitudinal direction is such that the other end is exposed from a first through-hole arranged on one side in the left-right direction via the guide member, and the cable holding portion is exposed from a second through-hole arranged on the other side in the left-right direction, An image forming apparatus characterized by the above.

Images