Flange, photoreceptor drum, and image forming apparatus

Abstract

The objective is to provide a flange, a photoreceptor drum, and an image forming apparatus that prevent contact between the flange and the substrate contact surface of the flange, which occurs when the flange is removed from the photoreceptor drum body and the photoreceptor drum is reused. [Solution] The flange 60 has an earth plate 61, an earth plate holding portion 62 that holds the earth plate 61, and a fitting portion 64 that fixes the earth plate holding portion 62 in the axial direction and fits into the inner surface of the base material 52. The earth plate 61 has a projection 61b that protrudes so as to contact the inner surface of the base material 52 so as to be electrically connected to a photoreceptor drum body 56 on which a photosensitive layer 54 is formed on the surface of the cylindrical base material 52. The flange 60 has a relationship between the distance X from the end of the projection 61b to the contact surface of the earth plate 61 with the earth plate holding portion 62, the distance Y from the end of the contact surface of the earth plate holding portion 62 with the earth plate 61 to the end of the base material contact surface 65, and the distance Z from the end of the base material contact surface 65 to the contact surface of the fitting portion 64 with the earth plate holding portion 62, where YX > 0 and Z > 300 μm.

Description

Technical Field

[0001] The present disclosure relates to a flange, a photoreceptor drum, and an image forming apparatus.

Background Art

[0002] Patent Document 1 discloses a resin flange in which an earth plate having a shape that contacts both the photoreceptor and the central axis to electrically connect them is fixed in an end face on the fitting portion side that is fitted into either the shaft hole supported by the central axis or the opening end of the photoreceptor.

[0003] Patent Document 2 discloses a resin flange portion that is fitted inside the opening end of a photoreceptor made of a base body and includes a transmission mechanism for rotational driving force formed on the outer periphery and a central hole, and a resin flange formed by connecting an earth plate that conducts electricity to connect the shaft that rotatably supports the photoreceptor through the central hole and the base body.

[0004] Patent Document 3 discloses a photoreceptor drum with a flange in which a plurality of elastically deformable claws are provided on the flange, a fitting portion that fits with the claws of the flange is provided near the open end of the photoreceptor drum, and the claws of the flange are fitted into the fitting portion of the photoreceptor drum to couple the photoreceptor drum and the flange.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] The photoreceptor drum is cleaned to remove any attached toner. However, this process wears down the surface layer of the photoreceptor drum. Therefore, the worn and deteriorated surface layer of the photoreceptor drum is sometimes removed, a new surface layer is formed, and the photoreceptor drum is reused. The photoreceptor drum is also provided with a flange that rotatably supports the drum body relative to the image forming apparatus. The flange is also provided with a grounding plate that electrically connects to the photoreceptor drum body.

[0007] However, when the flange is removed from the photoreceptor drum and the drum is reused, the grounding plate on the flange may scratch the inside of the substrate of the photoreceptor drum. If the flange is then attached to the photoreceptor drum with this scratch on the inside of the substrate, the flange will come into contact with the scratch, degrading the positional accuracy of the flange and causing uneven image density.

[0008] The purpose of this disclosure is to provide a flange, a photoreceptor drum, and an image forming apparatus that prevent contact between the flange and the substrate contact surface of the flange when the flange is removed from the photoreceptor drum body and the photoreceptor drum is reused. [Means for solving the problem]

[0009] A flange according to a first aspect of the present disclosure comprises: an earth plate having a projection that protrudes so as to contact the inner surface of a cylindrical substrate so as to be electrically connected to a photoreceptor drum body having a photosensitive layer formed on the surface of the substrate; an earth plate holding portion for holding the earth plate; and a fitting portion that fixes the earth plate holding portion in the axial direction and has a substrate contact surface that contacts the inner surface of the substrate, and is fitted to the opening end of the substrate with the substrate contact surface in contact with the inner surface of the opening end of the substrate so as to fix the earth plate held by the earth plate holding portion in a position such that the projection contacts the inner surface of the substrate, wherein the relationship between the distance X from the end of the projection to the contact surface of the earth plate with the earth plate holding portion of the earth plate, the distance Y from the end of the contact surface of the earth plate holding portion with the earth plate to the end of the substrate contact surface, and the distance Z from the end of the substrate contact surface to the contact surface of the earth plate holding portion of the fitting portion with the earth plate holding portion is YX > 0, Z > 300 μm, and is fitted to at least one opening end of the photoreceptor drum body.

[0010] The flange of the second aspect of this disclosure is such that, in the flange of the first aspect, the relationship between distance X and distance Z is X > Z.

[0011] The flange of the third aspect of the present disclosure is the flange of the first aspect, wherein the distance X is the distance at which the protrusion does not come into contact with the fitting portion when it is removed from the photoreceptor drum body.

[0012] The flange of the fourth aspect of the present disclosure, in the flange of the first aspect, when mounted on the photoreceptor drum body, the end of the protrusion is tilted in the direction opposite to the insertion direction, and when removed from the photoreceptor drum body, the end of the protrusion, which was tilted in the direction opposite to the insertion direction, is tilted in the direction opposite to the removal direction.

[0013] A photoreceptor drum according to a fifth aspect of the present disclosure comprises a photoreceptor drum body having a photosensitive layer formed on the surface of a cylindrical substrate, an earth plate having a protruding portion that protrudes to contact the inner surface of the substrate so as to be electrically connected to the photoreceptor drum body, an earth plate holder for holding the earth plate, and a substrate contact surface that fixes the earth plate holder in the axial direction and contacts the inner surface of the substrate, wherein the earth plate held by the earth plate holder is fixed in a position such that the protruding portion contacts the inner surface of the substrate. The photoreceptor drum body comprises a flange that fits onto at least one end of the opening, the flange having a fitting portion that is fitted onto the opening end of the substrate while in contact with the inner surface of the opening end of the substrate, wherein the relationship between the distance X from the end of the protrusion to the contact surface of the earth plate holding portion of the earth plate, the distance Y from the end of the contact surface of the earth plate holding portion with the earth plate to the end of the substrate contact surface, and the distance Z from the end of the substrate contact surface to the contact surface of the fitting portion with the earth plate holding portion is YX > 0, Z > 300 μm.

[0014] An image forming apparatus according to a sixth aspect of the present disclosure includes: a photoreceptor drum body having a photosensitive layer formed on the surface of a cylindrical substrate; an earth plate having a protruding portion that protrudes to contact the inner surface of the substrate so as to be electrically connected to the photoreceptor drum body; an earth plate holder for holding the earth plate; and a fitting portion that fixes the earth plate holder in the axial direction and has a substrate contact surface that contacts the inner surface of the substrate, and is fitted to the opening end of the substrate such that the earth plate held by the earth plate holder is fixed in a position such that the protruding portion contacts the inner surface of the substrate, with the substrate contact surface in contact with the inner surface of the opening end of the substrate. A photoreceptor drum comprising a flange fitted to at least one opening end of the photoreceptor drum body, wherein the relationship between the distance X from the end of the protruding portion to the contact surface of the earth plate with the earth plate holding portion of the earth plate, the distance Y from the end of the contact surface of the earth plate holding portion with the earth plate to the end of the substrate contact surface, and the distance Z from the end of the substrate contact surface to the contact surface of the fitting portion with the earth plate holding portion is YX>0, Z>300μm; and an image forming unit that develops an electrostatic latent image formed on the photosensitive layer of the photoreceptor drum and transfers it to a recording medium to form an image on the recording medium. [Effects of the Invention]

[0015] According to the flange of the first aspect of this disclosure, it is possible to prevent the flange from coming into contact with the substrate contact surface of the flange when the flange is removed from the photoreceptor drum body and the photoreceptor drum is reused, thereby preventing damage to the inside of the substrate from occurring.

[0016] According to the flange of the second aspect of this disclosure, the positional accuracy of the flange can be improved while electrically connecting the photoreceptor drum body to the ground plate.

[0017] According to the flange of the third aspect of this disclosure, when removing the flange from the photoreceptor drum body, the end of the ground plate can be prevented from coming into contact with the substrate contact surface of the flange.

[0018] According to the flange of the fourth aspect of the present disclosure, when the photoreceptor drum is reused by removing the flange from the photoreceptor drum main body, the contact surface of the flange with the base material can be prevented from contacting the inner damage of the base material that occurs.

[0019] According to the photoreceptor drum of the fifth aspect of the present disclosure, it is possible to prevent the contact between the inner damage of the base material that occurs when the flange is removed from the photoreceptor drum main body and the photoreceptor drum is reused, and the contact surface of the flange with the base material.

[0020] According to the image forming apparatus of the sixth aspect of the present disclosure, it is possible to prevent the contact between the inner damage of the base material that occurs when the flange is removed from the photoreceptor drum main body and the photoreceptor drum is reused, and the contact surface of the flange with the base material.

Brief Description of the Drawings

[0021] [Figure 1] It is a schematic diagram showing the configuration of an image forming apparatus according to an embodiment of the present disclosure. [Figure 2] (A) is a longitudinal sectional view around the end of a photoreceptor drum according to an embodiment of the present disclosure, and (B) is a sectional view taken along line A-A of (A). [Figure 3] It is a longitudinal sectional view of a flange attached to the end of a photoreceptor drum according to an embodiment of the present disclosure. [Figure 4] (A) is a diagram showing a state of attaching a flange to a photoreceptor drum main body. (B) is a diagram showing a state of removing the flange from a state where the flange is attached to the photoreceptor drum main body. (C) is a diagram showing a state of removing the flange from the photoreceptor drum main body. [Figure 5] It is a diagram showing Examples 1 to 3 in which an image is formed on a recording medium by an image forming apparatus using a photoreceptor drum with a flange according to an embodiment of the present disclosure, and Comparative Examples 1 and 2 in which an image is formed on a recording medium by an image forming apparatus using a photoreceptor drum with a flange according to a comparative example.

Modes for Carrying Out the Invention

[0022] Next, one embodiment of the present disclosure will be described in detail with reference to the drawings.

[0023] Figure 1 shows the configuration of an image forming apparatus 10, which is one embodiment of the present disclosure.

[0024] The image forming apparatus 10 includes a printing apparatus 21 and an image reading apparatus 34 as printing mechanisms. The printing apparatus 21 has, for example, three paper supply cassettes 22. Each of these paper supply cassettes 22 is provided with a paper supply head 23.

[0025] When one of the paper supply cassettes 22 is selected, the supply head 23 is activated and paper is supplied from the selected paper supply cassette 22 to the image forming unit 25 via the paper supply path 24, which is the transport path.

[0026] The image forming unit 25 has cylindrical photoreceptor drums 26 of yellow, magenta, cyan, and black arranged in a row, and an intermediate transfer belt 27 is provided.

[0027] Around each photoreceptor drum 26, a charging device, exposure device, developing device, primary transfer device, and cleaning device (not shown) are arranged. The toner image formed on each color photoreceptor drum 26 is transferred to the intermediate transfer belt 27. If set to black and white, only black is enabled.

[0028] The toner image on the intermediate transfer belt 27 is transferred to the paper, which serves as the recording medium, by the secondary transfer roll 28. The paper is then transported to the fuser unit 29 by the transport belt 41, where it is fixed. The paper with the fixed toner image then passes through the paper discharge path 30, which is the transport path, and is discharged to the discharge tray 31 by the discharge roll 42.

[0029] However, if double-sided printing is set, the paper, whose surface has been fixed by the fuser 29, is sent from the paper discharge path 30 to the inversion device 32 via the guide member 37 and the inversion roll 38. The paper is then inverted in the inversion device 32, sent to the paper inversion path 33 via the guide member 39, returned to the paper supply path 24, and sent to the image forming unit 25 for printing on the reverse side.

[0030] The image reading device 34 has an automatic document feeder 35 capable of reading double-sided documents. The document is fed to the platen 36 by this automatic document feeder 35, and the image of the document is read on the platen 36 by a reading unit consisting of a CCD or the like. The automatic document feeder 35 also serves as the platen cover. By opening this platen cover, the document can be placed on the platen 36. The opening and closing of this platen cover can be detected by a platen cover opening / closing detector.

[0031] Furthermore, the image forming apparatus 10 is equipped with a facsimile modem connected to a public telephone line and a network communication device connected to a network such as a LAN. By using the network communication device provided in the image forming apparatus 10, images read by the image reading device 34 can be transmitted to terminal devices connected to the network. By performing this process, the image forming apparatus 10 also functions as a facsimile transmission device.

[0032] Next, the details of the photoreceptor drum 26 will be explained using Figures 2 and 3. Figure 2(A) is a longitudinal cross-sectional view of the area around the end of the photoreceptor drum 26, and Figure 2(B) is a cross-sectional view of line AA in Figure 2(A). Figure 3 is a longitudinal cross-sectional view of the flange 60 attached to the end of the photoreceptor drum 26.

[0033] The photoreceptor drum 26 comprises a hollow cylindrical photoreceptor drum body 56 and flanges 60 attached to one or both ends of the opening of the photoreceptor drum body 56, which rotatably support the photoreceptor drum body 56. The flanges 60 are configured to be detachably attached to the photoreceptor drum body 56.

[0034] The photosensitive drum body 56 has a hollow cylindrical base material 52, and a photosensitive layer 54 is formed on the surface of the base material 52. The base material 52 is made of, for example, aluminum.

[0035] The flange 60 includes a plate-shaped grounding plate 61, a grounding plate holding portion 62 for holding the grounding plate 61, and a fitting portion 64 that fixes the grounding plate holding portion 62 in the axial direction and fits into the inner surface of the base material 52. The grounding plate holding portion 62 is cylindrical in shape. The grounding plate holding portion 62 and the fitting portion 64 are made of, for example, resin and are formed coaxially. The grounding plate holding portion 62 and the fitting portion 64 may be formed integrally or as separate parts.

[0036] The grounding plate 61 is made of a conductive material and has a disc-shaped base portion 61a and a projection portion 61b that protrudes concentrically from the base portion 61a so as to contact the inner surface of the substrate 52. Two projection portions 61b are formed in directions 180 degrees apart from the base portion 61a. By the projection portions 61b contacting the inner surface of the substrate 52, the grounding plate 61 electrically connects to the photoreceptor drum body 56. In other words, the grounding plate 61 is configured to electrically connect to the substrate 52. Note that the shape of the grounding plate 61 is not limited to that shown in Figure 2(B). For example, there may be two or more projection portions 61b, and furthermore, a hole may be formed approximately in the center of the grounding plate 61 through which a current-carrying shaft passes, so that a part of the grounding plate 61 contacts the current-carrying shaft.

[0037] The fitting portion 64 has a convex cylindrical shape. The fitting portion 64 has a base material contact surface 65 that abuts against the inner surface of the base material 52 and has a first fitting portion 64a that fixes the earth plate holding portion 62, and a second fitting portion 64b that is formed coaxially with the first fitting portion 64a and has a larger diameter than the outer diameter of the first fitting portion 64a and the base material 52.

[0038] The fitting portion 64 is fixed in a position where the protruding portion 61b of the earth plate 61, held by the earth plate holding portion 62, contacts the inner surface of the base material 52. Furthermore, with the base material contact surface 65 in contact with the inner surface of the opening end of the base material 52, the fitting portion 64 is fitted into the opening end of the base material 52.

[0039] The relationship between the flange 60, the distance X from the end of the protruding portion 61b of the earth plate 61 to the contact surface of the earth plate 61 with the earth plate holding portion 62, the distance Y from the end of the contact surface of the earth plate holding portion 62 with the earth plate 61 to the end of the base material contact surface 65, and the distance Z from the end of the base material contact surface 65 to the contact surface of the fitting portion 64 with the earth plate holding portion 62 is as follows: YX>0 Z > 300 μm Let's assume that.

[0040] Furthermore, let the relationship between distance X and distance Z be such that X > Z.

[0041] Here, distance X is the distance at which the protruding portion 61b of the ground plate 61 does not come into contact with the fitting portion 64 when the flange 60 is removed from the photoreceptor drum body 56. Distance Z is the distance at which the ground plate holding portion 62 does not come into contact with the inner surface of the base material 52.

[0042] As described above, a ground plate holding portion 62 is provided between the fitting portion 64 of the flange 60 and the ground plate 61, and the distances X, Y, and Z are set to the dimensions described above.

[0043] Next, the process of attaching the flange 60 to the photoreceptor drum body 56 and removing the flange 60 from the photoreceptor drum body 56 after the photosensitive layer 54 has worn off will be explained using Figure 4.

[0044] Figure 4(A) shows the process of attaching the flange 60 to the photoreceptor drum body 56. Figure 4(B) shows the process of removing the flange 60 from the photoreceptor drum body 56 after it has been attached. Figure 4(C) shows the process of removing the flange 60 from the photoreceptor drum body 56.

[0045] As shown in Figure 4(A), when the flange 60 is attached to the photoreceptor drum body 56, the end of the protruding portion 61b bends and tilts in the opposite direction to the insertion direction (direction of the arrow in Figure 4(A)) and in the direction of escape. This suppresses the occurrence of large scratches on the inner surface of the substrate 52.

[0046] Then, as shown in Figure 4(B), when the flange 60 is removed from the photoreceptor drum body 56, the end of the protruding portion 61b, which was tilted and curved in the opposite direction to the insertion direction, tilts and curves in the opposite direction to the removal direction (the direction of the arrow in Figure 4(B)). In other words, the direction of the curvature of the ground plate 61 changes. That is, inside the base material 52, the protruding portion 61b curves back from the opposite direction to the insertion direction to the opposite direction to the removal direction.

[0047] When the direction of curvature of this protrusion 61b changes (it bends back), a large scratch may occur on the inner surface of the base material 52. However, the location where the scratch occurs on the inner surface of the base material 52 is far from the opening end of the base material 52, and is different from the location where the base material contact surface 65 of the opening end of the base material 52 contacts the inner surface of the base material 52. In other words, by using the flange 60, even if the inner surface of the base material 52 is scratched due to the bending of the ground plate 61, the scratch formed on the base material 52 can be prevented from contacting the base material contact surface 65 of the fitting portion 64.

[0048] Then, as shown in Figure 4(C), the end of the protruding portion 61b, which was tilted and curved in the opposite direction to the direction of removal (the direction of the arrow in Figure 4(C)), is removed from the photoreceptor drum body 56 while remaining tilted and curved. At this time, the end of the protruding portion 61b of the ground plate 61 tilts and curves in the opposite direction to the direction of removal, in the direction of escape. As a result, large scratches on the inner surface of the base material 52 are suppressed.

[0049] In other words, when the flange 60 is removed from the photoreceptor drum body 56 and the photoreceptor drum body 56 is reused, it is possible to prevent the scratches on the inside of the substrate 52 that occur from coming into contact with the substrate contact surface 65 of the flange 60. This means that the eccentricity of the flange 60 can be suppressed and the positional accuracy can be improved. As a result, the occurrence of uneven image density can be suppressed. [Examples]

[0050] The following will provide a detailed explanation with reference to examples and comparative examples, but this embodiment is not limited to the following examples.

[0051] In Example 1, an image was formed by attaching and detaching a flange to the photoreceptor drum body. The difference between Y (the distance Y from the end of the contact surface of the earth plate holding portion 62 of the flange 60 with the earth plate 61 to the end of the substrate contact surface 65) and X (the distance X from the end of the protruding portion 61b of the earth plate 61 to the contact surface of the earth plate holding portion 62 of the earth plate 61) was 10 mm, and the distance Z (the distance Z from the end of the substrate contact surface 65 to the contact surface of the fitting portion 64 with the earth plate holding portion 62) was 1 mm. In Example 2, an image was formed by attaching and detaching a flange with the above-mentioned YX of 2 mm and distance Z of 1 mm to the photoreceptor drum body. In Example 3, an image was formed by attaching and detaching a flange with the above-mentioned YX of 10 mm and distance Z of 350 μm to the photoreceptor drum body. In Comparative Example 1, an image was formed by attaching and detaching a flange with the above-mentioned YX of -2 mm and distance Z of 1 mm to the photoreceptor drum body. In Comparative Example 2, an image was formed by attaching and detaching a flange with a YX of 10 mm and a distance Z of 250 μm, as described above, to the photoreceptor drum body.

[0052] The image density unevenness of the images formed on the paper in Examples 1-3 and Comparative Examples 1 and 2 was evaluated, and the results are shown in Figure 5. In Figure 5, ○ indicates that no image density unevenness occurred, and × indicates that image density unevenness occurred.

[0053] As shown in Figure 5, it was confirmed that image density unevenness was suppressed when image formation was performed using the photoreceptor drums with flanges attached in Examples 1 to 3, compared to when using the photoreceptor drums with flanges attached in Comparative Examples 1 and 2.

[0054] [Differentiation] Although the above embodiment was described using a case where a YMCK four-color image forming unit is provided, this disclosure is not limited thereto. The same can be applied to cases where an image forming unit with four or more colors, or a black and white (monochrome) image forming unit, is provided.

[0055] [Note] The following are preferred forms of this disclosure.

[0056] (((1))) An earth plate having a protruding portion that contacts the inner surface of a cylindrical substrate so as to be electrically connected to a photoreceptor drum body having a photosensitive layer formed on the surface of the substrate, The grounding plate holding part that holds the grounding plate, The grounding plate holding portion is fixed in the axial direction and has a substrate contact surface that contacts the inner surface of the substrate, and the grounding plate held by the grounding plate holding portion is fixed in a position such that the protruding portion contacts the inner surface of the substrate, and the fitting portion is fitted to the opening end of the substrate with the substrate contact surface in contact with the inner surface of the opening end of the substrate, Equipped with, The relationship between the distance X from the end of the protruding portion to the contact surface of the earth plate with the earth plate holding portion of the earth plate, the distance Y from the end of the contact surface of the earth plate holding portion with the earth plate to the end of the base material contact surface, and the distance Z from the end of the base material contact surface to the contact surface of the fitting portion with the earth plate holding portion is as follows: YX>0 Z > 300 μm A flange that is fitted to at least one end of the opening of the photoreceptor drum body.

[0057] (((2))) The relationship between the aforementioned distance X and the aforementioned distance Z is, X>Z The flange described in (((1))).

[0058] (((3))) The flange according to (((1))) or (((2))), wherein the distance X is the distance at which the protrusion does not come into contact with the fitting portion when it is removed from the photoreceptor drum body.

[0059] (((4))) A flange according to any one of (((1))) to (((3))), wherein when attached to the photoreceptor drum body, the end of the protrusion is tilted in the direction opposite to the insertion direction, and when removed from the photoreceptor drum body, the end of the protrusion that was tilted in the direction opposite to the insertion direction is tilted in the direction opposite to the removal direction.

[0060] (((5))) A photoreceptor drum body having a photosensitive layer formed on the surface of a cylindrical substrate, The device comprises: an earth plate having a protruding portion that protrudes so as to contact the inner surface of the substrate so as to be electrically connected to the photoreceptor drum body; an earth plate holding portion that holds the earth plate; and a fitting portion that fixes the earth plate holding portion in the axial direction and has a substrate contact surface that contacts the inner surface of the substrate, and is fitted to the opening end of the substrate with the substrate contact surface in contact with the inner surface of the opening end of the substrate so as to fix the earth plate held by the earth plate holding portion in a position such that the protruding portion contacts the inner surface of the substrate. The relationship between the distance X from the end of the protruding portion to the contact surface of the earth plate with the earth plate holding portion of the earth plate, the distance Y from the end of the contact surface of the earth plate holding portion with the earth plate to the end of the base material contact surface, and the distance Z from the end of the base material contact surface to the contact surface of the fitting portion with the earth plate holding portion is as follows: YX>0 Z > 300 μm A flange that is fitted to at least one end of the opening of the photoreceptor drum body, A photosensitive drum equipped with a photoreceptor.

[0061] (((6))) A photoreceptor drum body having a photosensitive layer formed on the surface of a cylindrical substrate, The device comprises: an earth plate having a protruding portion that protrudes so as to contact the inner surface of the substrate so as to be electrically connected to the photoreceptor drum body; an earth plate holding portion that holds the earth plate; and a fitting portion that fixes the earth plate holding portion in the axial direction and has a substrate contact surface that contacts the inner surface of the substrate, and is fitted to the opening end of the substrate with the substrate contact surface in contact with the inner surface of the opening end of the substrate so as to fix the earth plate held by the earth plate holding portion in a position such that the protruding portion contacts the inner surface of the substrate. The relationship between the distance X from the end of the protruding portion to the contact surface of the earth plate with the earth plate holding portion of the earth plate, the distance Y from the end of the contact surface of the earth plate holding portion with the earth plate to the end of the base material contact surface, and the distance Z from the end of the base material contact surface to the contact surface of the fitting portion with the earth plate holding portion is as follows: YX>0 Z > 300 μm A photoreceptor drum comprising a flange fitted to at least one opening end of the photoreceptor drum body, An image forming unit that develops an electrostatic latent image formed on the photosensitive layer of the photosensitive drum and transfers it to the recording medium to form an image on the recording medium, An image forming apparatus equipped with the following features.

[0062] The effects of the configuration described below are explained below.

[0063] The flange in (((1))) prevents the inner surface of the substrate from coming into contact with the substrate contact surface of the flange when the flange is removed from the photoreceptor drum body and the photoreceptor drum is reused.

[0064] According to the flange of (((2))), the photoreceptor drum body can be electrically connected to the ground plate while improving the positional accuracy of the flange.

[0065] According to the flange of (((3))), when removing the flange from the photoreceptor drum body, the end of the ground plate will not come into contact with the substrate contact surface of the flange.

[0066] According to the flange of (((4))), the substrate contact surface of the flange can be prevented from coming into contact with scratches on the inside of the substrate that occur when the flange is removed from the photoreceptor drum body and the photoreceptor drum is reused.

[0067] According to the photoreceptor drum of (((5))), it is possible to prevent scratches on the inside of the substrate that occur when the flange is removed from the photoreceptor drum body and the photoreceptor drum is reused from coming into contact with the substrate contact surface of the flange.

[0068] According to the image forming apparatus of (((6))), it is possible to prevent scratches on the inside of the substrate that occur when the flange is removed from the photoreceptor drum body and the photoreceptor drum is reused from coming into contact with the substrate contact surface of the flange. [Explanation of Symbols]

[0069] 10 Image forming apparatus 26 Photoconductor drum 52 Base material 54 Photosensitive layer 56 Photoconductor drum unit 60 flange 61 Grounding plate 61a base 61b Protrusion 62 Grounding plate holding part 64 Fitting part 64a First mating section 64b Second mating section 65 Base material contact surface

Claims

1. An earth plate having a protruding portion that contacts the inner surface of a cylindrical substrate so as to be electrically connected to a photoreceptor drum body having a photosensitive layer formed on the surface of the substrate, The grounding plate holding part for holding the grounding plate, The grounding plate holding portion is fixed in the axial direction and has a substrate contact surface that contacts the inner surface of the substrate, and the grounding plate held by the grounding plate holding portion is fixed in a position such that the protruding portion contacts the inner surface of the substrate, and the fitting portion is fitted to the opening end of the substrate with the substrate contact surface in contact with the inner surface of the opening end of the substrate, Equipped with, The relationship between the distance X from the end of the protruding portion to the contact surface of the earth plate with the earth plate holding portion of the earth plate, the distance Y from the end of the contact surface of the earth plate holding portion with the earth plate to the end of the base material contact surface, and the distance Z from the end of the base material contact surface to the contact surface of the fitting portion with the earth plate holding portion is as follows: Y - X > 0 Z > 300 μm A flange that is fitted to at least one end of the opening of the photoreceptor drum body.

2. The relationship between the aforementioned distance X and the aforementioned distance Z is, X > Z The flange according to claim 1.

3. The flange according to claim 1, wherein the distance X is a distance at which the protruding portion does not come into contact with the fitting portion when it is removed from the photoreceptor drum body.

4. The flange according to claim 1, wherein when attached to the photoreceptor drum body, the end of the protruding portion is tilted in the direction opposite to the insertion direction, and when removed from the photoreceptor drum body, the end of the protruding portion that was tilted in the direction opposite to the insertion direction is tilted in the direction opposite to the removal direction.

5. A photosensitive drum body having a photosensitive layer formed on the surface of a cylindrical substrate, The device comprises: an earth plate having a protruding portion that protrudes so as to contact the inner surface of the substrate so as to be electrically connected to the photoreceptor drum body; an earth plate holding portion that holds the earth plate; and a fitting portion that fixes the earth plate holding portion in the axial direction and has a substrate contact surface that contacts the inner surface of the substrate, and is fitted to the opening end of the substrate with the substrate contact surface in contact with the inner surface of the opening end of the substrate so as to fix the earth plate held by the earth plate holding portion in a position such that the protruding portion contacts the inner surface of the substrate. The relationship between the distance X from the end of the protruding portion to the contact surface of the earth plate with the earth plate holding portion of the earth plate, the distance Y from the end of the contact surface of the earth plate holding portion with the earth plate to the end of the base material contact surface, and the distance Z from the end of the base material contact surface to the contact surface of the fitting portion with the earth plate holding portion is as follows: Y - X > 0 Z > 300 μm A flange fitted to at least one end of the opening of the photoreceptor drum body, A photosensitive drum equipped with a photoreceptor.

6. A photosensitive drum body having a photosensitive layer formed on the surface of a cylindrical substrate, The device comprises: an earth plate having a protruding portion that protrudes so as to contact the inner surface of the substrate so as to be electrically connected to the photoreceptor drum body; an earth plate holding portion that holds the earth plate; and a fitting portion that fixes the earth plate holding portion in the axial direction and has a substrate contact surface that contacts the inner surface of the substrate, and is fitted to the opening end of the substrate with the substrate contact surface in contact with the inner surface of the opening end of the substrate so as to fix the earth plate held by the earth plate holding portion in a position such that the protruding portion contacts the inner surface of the substrate. The relationship between the distance X from the end of the protruding portion to the contact surface of the earth plate with the earth plate holding portion of the earth plate, the distance Y from the end of the contact surface of the earth plate holding portion with the earth plate to the end of the base material contact surface, and the distance Z from the end of the base material contact surface to the contact surface of the fitting portion with the earth plate holding portion is as follows: Y - X > 0 Z > 300 μm A photoreceptor drum comprising a flange fitted to at least one opening end of the photoreceptor drum body, An image forming unit that develops an electrostatic latent image formed on the photosensitive layer of the photosensitive drum and transfers it to the recording medium to form an image on the recording medium, An image forming apparatus equipped with the following features.

Images