Roller holding unit, cartridge, and image forming apparatus

Abstract

To maintain the posture of a separation member toward a photoconductor drum in a state before the photoconductor drum is assembled to a roller holding unit.SOLUTION: A roller holding unit has: a roller member; bearing members that support a shank of the roller member and are movable in a first direction perpendicular to the rotation axis of the shank; a first urging member that urges the bearing members in the first direction; a first regulation member that can regulate the movement of the bearing members in the first direction from a first position; separation members that are rotatable around the shank; a second urging member that can urge the separation members in a second direction that is a rotation direction around the shank; and a second regulation member that can regulate the rotation of the separation members in the second direction. The separation members each have a cylindrical part that is mounted at an end in an axial direction of the shank, and a projection that projects from the cylindrical part in a radial direction of the shank.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a roller holding unit, a cartridge, and an image forming apparatus. [Background technology]

[0002] In electrophotographic image forming devices, rollers such as a developing roller, a charging roller, and a transfer roller contact a photosensitive drum during image formation. If other roller members continue to contact the photosensitive drum from the time the image forming device is shipped until the user begins using the device, contact marks may remain on the roller surface, affecting the image. To prevent this, the following method can be considered: A spacer member is fitted to the shaft of the other roller and abuts the photosensitive drum to prevent the photosensitive drum from contacting the other roller until the device is first used. Then, at the start of use, the abutting state of the spacer member is released, allowing the photosensitive drum and the other roller to contact each other. When assembling a product using such a spacer member, it is necessary to hold the roller and hold the abutting portion of the spacer member facing the photosensitive drum until the photosensitive drum is assembled into the roller holding unit.

[0003] Patent Document 1 proposes a configuration in which a spacing member fitted to a charging roller that contacts a photosensitive drum has an arc-shaped concave surface on the side opposite to the side facing the photosensitive drum, and the concave surface of the spacing member contacts the axial surface of another roller that is biased by the charging roller.This configuration allows the abutment portion of the spacing member to be held facing the photosensitive drum by the other roller that is biased by the charging roller even before the photosensitive drum is assembled. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-84516 Summary of the Invention [Problem to be solved by the invention]

[0005] In a configuration in which a separate component is biased against the roller that contacts the photosensitive drum, as in Patent Document 1, it is possible to hold the spacing member by utilizing the biasing force of that separate component. However, in a configuration in which a separate component is not biased against the roller that contacts the photosensitive drum, it is necessary for an operator or device to hold the spacing member during assembly.

[0006] The present invention aims to provide a technology that enables the position of a spacing member to be maintained facing a photosensitive drum before the photosensitive drum is assembled in an assembly process of assembling a photosensitive drum to a roller holding unit. [Means for solving the problem]

[0007] The present invention provides a roller holding unit that forms a part of an image forming apparatus or a part of a cartridge that is detachably mountable to a main body of an image forming apparatus by assembling a photosensitive drum, A frame body, a roller member having a shaft portion and rotating in contact with the photosensitive drum during image formation; a bearing member that rotatably supports the shaft portion, the bearing member being held by the frame so as to be movable in a first direction that is a direction perpendicular to the rotation axis of the shaft portion; a first biasing member that biases the bearing member in the first direction relative to the frame; When the photosensitive drum is not attached to the roller holding unit, a first restricting member configured to restrict movement of the bearing member in the first direction from a first position where the bearing member is positioned; a spacing member rotatable about the shaft; a second biasing member configured to bias the spacing member relative to the frame body in a second direction, which is a rotation direction around the shaft portion; a second restricting member configured to restrict the spacing member from rotating in the second direction, The spacing member has a cylindrical portion attached to an axial end of the shaft portion, and a protruding portion protruding from the cylindrical portion in a radial direction of the shaft portion. The roller holding unit is characterized by the above.

[0008] The present invention provides an image forming apparatus, A frame body, A photosensitive drum; a roller member having a shaft portion and rotating in contact with the photosensitive drum during image formation; a bearing member that rotatably supports the shaft portion, the bearing member being held by the frame body so as to be movable in a direction in which a distance from the photosensitive drum changes; a first biasing member that biases the bearing member relative to the frame body in a first direction that is a direction toward the photosensitive drum; a first restricting member configured to restrict movement of the bearing member in the first direction from a first position where the bearing member is positioned when the photosensitive drum is not assembled in the image forming apparatus; and a spacing member rotatable about the shaft; a second biasing member configured to bias the spacing member relative to the frame body in a second direction, which is a rotation direction around the shaft portion; a second restricting member configured to restrict the spacing member from rotating in the second direction, The spacing member has a cylindrical portion attached to an axial end of the shaft portion, and a protruding portion protruding from the cylindrical portion in a radial direction of the shaft portion. The image forming apparatus is characterized by the above.

[0009] The present invention provides a cartridge detachably mountable to a main body of an image forming apparatus, A frame body, A photosensitive drum; a roller member having a shaft portion and rotating in contact with the photosensitive drum during image formation; a bearing member that rotatably supports the shaft portion, the bearing member being held by the frame body so as to be movable in a direction in which a distance from the photosensitive drum changes; a first biasing member that biases the bearing member relative to the frame body in a first direction that is a direction toward the photosensitive drum; a first restricting member configured to restrict movement of the bearing member in the first direction from a first position at which the bearing member is positioned when the photosensitive drum is not assembled in the cartridge; a spacing member rotatable about the shaft; a second biasing member configured to bias the spacing member relative to the frame body in a second direction, which is a rotation direction around the shaft portion; a second restricting member configured to restrict the spacing member from rotating in the second direction, The spacing member has a cylindrical portion attached to an axial end of the shaft portion, and a protruding portion protruding from the cylindrical portion in a radial direction of the shaft portion. The cartridge is characterized by the above. [Effects of the Invention]

[0010] According to the present invention, in the assembly process of assembling the photosensitive drum to the roller holding unit, the attitude of the spacing member can be maintained facing the photosensitive drum before the photosensitive drum is assembled. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a partial side view of the non-driving side end of the charging unit according to the first embodiment. [Figure 2] 1 is a schematic cross-sectional view of an image forming apparatus according to a first embodiment. [Figure 3] FIG. 2 is a cross-sectional view of the process cartridge of the first embodiment. [Figure 4] FIG. 1 is a cross-sectional view of an image forming apparatus according to a first embodiment. [Figure 5] FIG. 1 is a cross-sectional view of an image forming apparatus according to a first embodiment. [Figure 6] FIG. 1 is a cross-sectional view of an image forming apparatus according to a first embodiment. [Figure 7] FIG. 2 is an exploded perspective view of the charging unit of the first embodiment. [Figure 8]FIG. 1 is an exploded perspective view of a development unit according to a first embodiment of the present invention; [Figure 9] FIG. 2 is an assembled perspective view of the process cartridge of the first embodiment. [Figure 10] FIG. 2 is a perspective view of the process cartridge according to the first embodiment. [Figure 11] FIG. 2 is a partial perspective view of the non-driving side end of the charging unit according to the first embodiment. [Figure 12] FIG. 2 is a partial side view of the non-driving side end of the charging unit according to the first embodiment. [Figure 13] FIG. 2 is a partial side view of the non-driving side end of the charging unit according to the first embodiment. [Figure 14] FIG. 10 is a partial side view of the non-drive side end of the development unit according to the second embodiment. [Figure 15] FIG. 11 is a partial side view of the non-driving side end of the transfer unit according to the third embodiment. [Figure 16] FIG. 2 is an exploded perspective view of the non-drive side of the charging unit according to the first embodiment. [Figure 17] FIG. 2 is a perspective view of the non-drive side of the charging unit of the first embodiment. [Figure 18] FIG. 2 is a cross-sectional view of the non-drive side of the charging unit of the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] The best mode for carrying out the present invention will be described in detail below with reference to the drawings and examples. However, the functions, materials, shapes, dimensions, relative positions, etc. of the components described in the examples may be changed as appropriate depending on the configuration of the device to which the invention is applied, various conditions, etc. Unless otherwise specified, it is not intended to limit the scope of the present invention to only those.

[0013] Example 1 A first embodiment of the present invention will be described below with reference to the drawings. In the first embodiment, an image forming apparatus to which four process cartridges can be detachably attached is exemplified. However, the number of process cartridges to be attached to the image forming apparatus is not limited to this. It can be set appropriately as needed.

[0014] In the embodiment described below, a laser beam printer is exemplified as one aspect of the image forming apparatus.

[0015] <General configuration of image forming apparatus> The overall configuration of an electrophotographic image forming apparatus 1 according to the first embodiment will be described with reference to Fig. 2. Fig. 2 is a schematic cross-sectional view of the image forming apparatus 1. Fig. 3 is a cross-sectional view of a process cartridge 100.

[0016] This image forming apparatus 1 is a four-color full-color laser beam printer that uses an electrophotographic process, and forms a color image on a recording medium 3. The image forming apparatus 1 is of a process cartridge type, and a process cartridge 100 is removably attached to the apparatus main body 2, and a color image is formed on the recording medium 3.

[0017] Here, with respect to the image forming apparatus 1, the side where the front door 10 is provided is referred to as the front (front face), and the side opposite the front is referred to as the back (rear face). When viewing the image forming apparatus 1 from the front, the right side is referred to as the drive side, the left side is referred to as the non-drive side, the upper side is referred to as the top face, and the lower side is referred to as the bottom face. Figure 2 is a cross-sectional view of the image forming apparatus 1 viewed from the non-drive side, with the front side of the page being the non-drive side of the image forming apparatus 1, the right side of the page being the front of the image forming apparatus 1, and the back side of the page being the drive side of the image forming apparatus 1.

[0018] The drive side of the process cartridge 100 is the side where a drum coupling member (photosensitive member coupling member) described later is arranged when viewed in the axial direction of the photosensitive drum 101. When viewed in the axial direction of the developing roller 103 (developing member), it is the side where a developing coupling member described later is arranged.

[0019] In the apparatus main body 2, first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) are arranged in a substantially horizontal direction.

[0020] The first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) each have the same electrophotographic process mechanism, but differ in the color and amount of developer (hereinafter referred to as toner). Therefore, in the following, unless a particular distinction is required, the suffixes Y to K will be omitted and the process cartridges will be described collectively.

[0021] A rotational driving force is transmitted to the first to fourth process cartridges 100 from a driving output section (details of which will be described later) of the main body 2 of the apparatus, and bias voltages (charging bias, developing bias, electrostatic residual detection bias, etc.) are supplied from contacts of the main body 2 of the apparatus (not shown).

[0022] 3, the process cartridge 100 of the first embodiment has a photosensitive drum 101 as an image carrier and a charging unit 120 equipped with charging means as process means acting on the photosensitive drum 101. Here, the charging unit 120 may have not only the charging means but also cleaning means as process means.

[0023] The process cartridge 100 also has a developing unit 150 equipped with a developing means for developing the electrostatic latent image on the photosensitive drum 101 .

[0024] The charging unit 120 and the developing unit 150 are coupled to each other. A more specific configuration of the process cartridge 100 will be described later.

[0025] The first process cartridge 100Y accommodates yellow (Y) toner in the developing frame, and forms a yellow toner image on the surface of the photosensitive drum 101.

[0026] The second process cartridge 100M accommodates magenta (M) toner in the developing frame, and forms a magenta toner image on the surface of the photosensitive drum 101.

[0027] The third process cartridge 100C accommodates cyan (C) toner in the developing frame, and forms a cyan toner image on the surface of the photosensitive drum 101.

[0028] The fourth process cartridge 100K accommodates black (K) toner in the developing frame, and forms a black toner image on the surface of the photosensitive drum 101.

[0029] A laser scanner unit 11 serving as an exposure means is provided above the first to fourth process cartridges 100. The laser scanner unit 11 outputs a laser beam 12 corresponding to image information. The laser beam 12 is then incident on the surface of the process cartridge 100. The light passes through the exposure window 128 and scans and exposes the surface of the photosensitive drum 101 .

[0030] An intermediate transfer unit 5 serving as a transfer member is provided below the first to fourth process cartridges 100. This intermediate transfer unit 5 has a drive roller 5e and a tension roller 5b, and a flexible transfer belt 5a is stretched over them.

[0031] The lower surfaces of the photosensitive drums 101 of the first to fourth process cartridges 100 are in contact with the upper surface of the transfer belt 5a. This contact area is the primary transfer portion. A primary transfer roller 5d is provided on the inner side of the transfer belt 5a, facing the photosensitive drum 101.

[0032] A secondary transfer roller 6 is brought into contact with the drive roller 5e via the transfer belt 5a. The contact area between the transfer belt 5a and the secondary transfer roller 6 is the secondary transfer portion.

[0033] A feeding unit 4 is provided below the intermediate transfer unit 5. The feeding unit 4 has a paper feed tray 4a that accommodates a stack of recording media 3, and a paper feed roller 4b.

[0034] A fixing device 7 and a paper discharge device 8 are provided in the upper right corner of the apparatus main body 2 in FIG.

[0035] The toner image is fixed onto the recording medium 3 by a fixing means provided in a fixing device 7 , and the recording medium 3 is then discharged onto a paper discharge tray 9 .

[0036] <Image formation operation> The operation for forming a full color image is as follows.

[0037] The photosensitive drums 101 of the first to fourth process cartridges 100 are rotated at a predetermined speed (in the direction of arrow A in FIG. 3). The transfer belt 5a is also rotated in the forward direction (in the direction of arrow B in FIG. 2) relative to the rotation of the photosensitive drums 101 at a speed corresponding to the speed of the photosensitive drums 101.

[0038] The laser scanner unit 11 is also driven. In synchronization with the driving of the laser scanner unit 11, in each process cartridge 100, a charging roller 102 as a roller member uniformly charges the surface of the photosensitive drum 101 to a predetermined polarity and potential. The laser scanner unit 11 scans and exposes the surface of each photosensitive drum 101 with a laser beam 12 in accordance with an image signal for each color.

[0039] As a result, an electrostatic latent image corresponding to the image signal for the corresponding color is formed on the surface of each photosensitive drum 101. The formed electrostatic latent image is developed by the developing roller 103, which is rotated at a predetermined speed in the forward direction (the direction of arrow C in FIG. 3) relative to the rotation of the photosensitive drum 101.

[0040] By the electrophotographic image forming process operation as described above, a yellow toner image corresponding to the yellow component of the full-color image is formed on the photosensitive drum 101 of the first process cartridge 100Y, and then the toner image is primarily transferred onto the transfer belt 5a.

[0041] Similarly, a magenta toner image corresponding to the magenta component of the full-color image is formed on the photosensitive drum 101 of the second process cartridge 100M. Then, this toner image is primarily transferred onto the transfer belt 5a, superimposed on the yellow toner image already transferred onto the transfer belt 5a.

[0042] Similarly, a cyan toner image corresponding to the cyan component of the full-color image is formed on the photosensitive drum 101 of the third process cartridge 100C. The yellow and magenta toner images are transferred onto the transfer sheet 5a in a superimposed manner.

[0043] Similarly, a black toner image corresponding to the black component of the full-color image is formed on the photosensitive drum 101 of the fourth process cartridge 100K. Then, this toner image is primarily transferred onto the transfer belt 5a, superimposed on the yellow, magenta, and cyan toner images already transferred onto the transfer belt 5a.

[0044] In this way, an unfixed full-color toner image of four colors, yellow, magenta, cyan, and black, is formed on the transfer belt 5a.

[0045] Meanwhile, the recording media 3 are separated and fed one by one at a predetermined control timing, and the recording media 3 are introduced into a secondary transfer section, which is a contact point between the secondary transfer roller 6 and the transfer belt 5a, at a predetermined control timing.

[0046] As a result, the four-color superimposed toner image on the transfer belt 5a is transferred onto the surface of the recording medium 3 in a batch in sequence while the recording medium 3 is being transported to the secondary transfer portion.

[0047] The configuration of the image forming apparatus 1 will be described in more detail below.

[0048] <Process cartridge installation / removal configuration overview> The cartridge tray (hereinafter referred to as the tray) 20 that supports the process cartridge 100 will be described in further detail with reference to Figures 4 to 6. Figure 4 is a cross-sectional view of the image forming apparatus 1 in which the tray 20 is located inside the apparatus main body 2 with the front door 10 open. Figure 5 is a cross-sectional view of the image forming apparatus 1 in which the tray 20 is located outside the apparatus main body 2 with the front door 10 open and the process cartridge 100 is housed inside the tray 20. Figure 6 is a cross-sectional view of the image forming apparatus 1 in which the tray 20 is located outside the apparatus main body 2 with the front door 10 open and the process cartridge 100 has been removed from the tray 20.

[0049] 4 and 5, the tray 20 is movable in the direction of arrow X1 (pushing direction) and the direction of arrow X2 (pulling out direction), which are substantially horizontal directions, relative to the apparatus main body 2. That is, the tray 20 is provided so as to be able to be pulled out and pushed into the apparatus main body 2, and is configured so as to be movable in a substantially horizontal direction when the apparatus main body 2 is installed on a horizontal surface. Here, the state in which the tray 20 is positioned inside the apparatus main body 2 with the front door 10 open (the state in FIG. 4) is referred to as the inside position. Also, the state in which the tray 20 is positioned outside the apparatus main body 2 (the state in FIG. 5) is referred to as the outside position. In these inside and outside positions, the photosensitive drum 101 and the transfer belt 5a are spaced apart.

[0050] The tray 20 also has a mounting portion 20a at its outer position, into which the first process cartridge 100Y can be removably mounted, as shown in FIG. 6. The tray 20 also has mounting portions 20a into which the second to fourth process cartridges 100M, 100C, and 100K can be removably mounted. The process cartridge 100, while placed in the mounting portion 20a, moves toward the inside of the apparatus main body 2 as the tray 20 moves. In this embodiment, when the front door 10 is closed, the intermediate transfer unit 5 is raised in the direction of arrow Z1 by a link mechanism (not shown) and moves to a position for image formation (a position where the photosensitive drum 101 and the transfer belt 5a come into contact with each other). When the front door 10 is opened, the intermediate transfer unit 5 is lowered in the direction of arrow Z2, and the photosensitive drum 101 and the transfer belt 5a are separated from each other.

[0051] As described above, the tray 20 allows a plurality of process cartridges 100 to be moved together to a position inside the apparatus main body 2 where image formation is possible, and also allows a plurality of process cartridges 100 to be moved together to a position inside the apparatus main body 2 where image formation is possible. It can be pulled outwards.

[0052] <Overall structure of the process cartridge> The structure of the process cartridge will be described with reference to FIGS.

[0053] Fig. 7 is an exploded perspective view of the charging unit 120. Fig. 8 is an exploded perspective view of the developing unit 150. Fig. 9 is an assembled perspective view of the process cartridge 100 as seen from the drive side, which is one end side in the axial direction of the photosensitive drum 101. Fig. 10 is a perspective view of the process cartridge 100 as seen from the drive side.

[0054] The process cartridge 100 includes a photosensitive drum 101 and process means acting on the photosensitive drum 101. The process means includes a charging roller 102 (roller member) as charging means for charging the photosensitive drum 101, a developing roller 103 as developing means for developing the latent image formed on the photosensitive drum 101, and the like. The process cartridge 100 is divided into a charging unit 120 and a developing unit 150.

[0055] In the following description, the longitudinal direction Y of the charging unit 120 and the developing unit 150 is a direction substantially parallel to the rotation axis a of the photosensitive drum 101 (FIG. 9).

[0056] <Charging unit configuration> As shown in FIGS. 7 and 9 , the charging unit 120 is composed of a photosensitive drum 101, a charging roller 102, and a frame 121. The charging unit 120 also includes a charging roller bearing unit 126 disposed at the drive-side end of the charging roller 102, and a charging roller bearing unit 127 disposed at the non-drive-side end. The charging roller bearing unit 126 includes a driving-side charging roller bearing 126a that rotatably supports the charging roller 102, and a pressure spring 126b that urges the charging roller 102 toward the photosensitive drum 101. Similarly, the charging roller bearing unit 127 includes a non-driving-side charging roller bearing 127a that rotatably supports the charging roller 102, and a pressure spring 127b that urges the charging roller 102 toward the photosensitive drum 101. The shaft 102a of the charging roller 102 is rotatably supported by the driving-side charging roller bearing 126a and the non-driving-side charging roller bearing 127a, which serve as bearing members. The drive-side charge roller bearing 126a and the non-drive-side charge roller bearing 127a are attached to a bearing attachment portion 121a of the frame 121, and are urged (in the direction of arrow F in FIG. 3) against the photosensitive drum 101 by pressure springs 126b and 127b serving as urging members. A drive-side spacing member 130 is attached to the drive-side end of the shaft portion 102a of the charge roller 102, and a non-drive-side spacing member 131 is attached to the non-drive-side end. The photosensitive drum 101 is rotatably supported by a drive-side cartridge cover member 122 and a non-drive-side cartridge cover member 123, which are provided at both ends of the process cartridge 100 in the longitudinal direction.

[0057] As shown in FIG. 9, a coupling member 125 for transmitting a driving force to the photosensitive drum 101 is provided at one end in the longitudinal direction of the photosensitive drum 101. The coupling member 125 engages with a main body-side drum drive coupling 30 (see FIG. 6) serving as a drum drive output unit of the apparatus main body 2, and the driving force of a drive motor (not shown) of the apparatus main body 2 is transmitted to the photosensitive drum 101, causing it to rotate in the direction of arrow A in FIG. 3. The photosensitive drum 101 also has a drum flange 124 at the other end in the longitudinal direction. A drive-side charge roller bearing 126a and a non-drive-side charge roller bearing 127a that support the charge roller 102 are supported by the frame 121 so that the charge roller 102 can contact the photosensitive drum 101 and rotate following it (in the direction of arrow E in FIG. 3).

[0058] <Configuration of the development unit> 3 and 8, the developing unit 150 is composed of a developing roller 103, a toner transport roller 104, a developing blade 156, a developing frame, etc. The developing frame is a first developing frame. The developing frame 103 is made up of a first developing frame 151 and a second developing frame 152. The first developing frame 151 and the second developing frame 152 are joined by ultrasonic welding or the like. The developing frame has a toner storage portion 162 that stores toner to be supplied to the developing roller 103. The developing frame 103 also rotatably supports the developing roller 103 and the toner transport roller 104 via a drive-side bearing 153 and a non-drive-side bearing 154, and holds a developing blade 156 that regulates the thickness of the toner layer on the circumferential surface of the developing roller 103.

[0059] The developing blade 156 is made by attaching an elastic member 156b, which is a sheet metal with a thickness of about 0.1 mm, to a supporting member 156a, which is a metal material with an L-shaped cross section, by welding, etc. The developing blade 156 is attached to the developing frame body at two points, one end side and the other end side in the longitudinal direction, with fixing screws 156c.

[0060] A development drive input gear 159 for transmitting a driving force to the development unit 150 is provided on one end side in the longitudinal direction of the development unit 150. The development drive input gear 159 is provided with a development input coupling 159a that receives driving force from the main body side development drive coupling 40 (see FIG. 6) of the apparatus main body 2, and the driving force of a drive motor (not shown) of the apparatus main body 2 is input to the development unit 150.

[0061] The driving force input to the developing unit 150 is transmitted to the developing roller gear 157, thereby rotating the developing roller 103 in the direction of arrow C in FIG. 3. Furthermore, the driving force is transmitted to the toner transport roller gear 158, thereby rotating the toner transport roller 104 in the direction of arrow D in FIG. 3. Furthermore, the driving force is transmitted to the agitating gear 160, thereby rotating the agitating member 161 in the direction of arrow G in FIG. 3, thereby agitating the toner in the toner storage section 162. The agitating member 161 has a rotating shaft 161a parallel to the rotational axis direction of the developing roller 103 and an agitating sheet 161b, which is a flexible sheet and serves as a transport member. One end of the agitating sheet 161b is attached to the rotating shaft 161a, and the other end of the agitating sheet 161b is a free end. When the rotating shaft 161a rotates, the agitating sheet 161b also rotates, thereby agitating the toner by the agitating sheet 161b.

[0062] At one end of the developing unit 150 in the longitudinal direction, a developing device cover member 155 that supports and covers a developing device drive input gear 159 is provided.

[0063] <Assembling the charging unit and developing unit> The assembly of the charging unit 120 and the developing unit 150 will be described using Figure 9. The charging unit 120 and the developing unit 150 are connected by a drive-side cartridge cover member 122 and a non-drive-side cartridge cover member 123, which are provided at both longitudinal ends of the process cartridge 100. The drive-side cartridge cover member 122, which is provided at one longitudinal end of the process cartridge 100, is provided with a developing unit support hole 122b for supporting the developing unit 150 so that it can swing (move). Similarly, the non-drive-side cartridge cover member 123, which is provided at the other longitudinal end of the process cartridge 100, is provided with a developing unit support hole 123b for supporting the developing unit 150 so that it can swing. Furthermore, the drive-side cartridge cover member 122 and the non-drive-side cartridge cover member 123 are provided with drum support holes 122a and 123a, respectively, for rotatably supporting the photosensitive drum 101. Here, at one end, the outer diameter portion of the cylindrical portion 155a of the developing cover member 155 is fitted into the developing unit support hole 122b of the driving side cartridge cover member 122. At the other end, the outer diameter portion of the cylindrical portion (not shown) of the non-driving side bearing 154 is fitted into the developing unit support hole 123b of the non-driving side cartridge cover member 123. Furthermore, both longitudinal ends of the photosensitive drum 101 are fitted into the drum support hole 122a of the driving side cartridge cover member 122 and the drum support hole 123a of the non-driving side cartridge cover member 123. Then, the driving side cartridge cover member 122 and the non-driving side cartridge cover member 123 are fixed to the charging unit 120 with screws, adhesive, etc. (not shown). As a result, the developing The unit 150 is rotatably supported relative to the charging unit 120 (photosensitive drum 101) by a drive-side cartridge cover member 122 and a non-drive-side cartridge cover member 123. The developing roller 103 can be positioned to act on the photosensitive drum 101 during image formation.

[0064] The charging unit 120 and the developing unit 150 are assembled through the above steps and integrally formed into the process cartridge 100, as shown in FIG.

[0065] The axis connecting the center of the developing unit support hole 122b of the drive-side cartridge cover member 122 and the center of the developing unit support hole 123b of the non-drive-side cartridge cover member 123 is referred to as the swing axis b. Here, the cylindrical portion 155a of the developing unit cover member 155 on one end side is coaxial with the developing input coupling 159a. In other words, the developing unit 150 is configured so that a driving force is transmitted from the apparatus main body 2 at this swing axis b. The developing unit 150 is also supported so as to be rotatable about the swing axis b.

[0066] <Charging roller spacing configuration> The separation structure of the charging roller 102 will be described with reference to Fig. 11. Fig. 11 is a partial perspective view of the end of the non-drive side charging roller 102. Although the non-drive side will be used for the description, the opposite drive side has a similar structure.

[0067] The non-drive-side spacing member 131 is attached by fitting the cylindrical portion 131a of the non-drive-side spacing member 131 onto the shaft portion 102a of the charge roller 102. This allows the non-drive-side spacing member 131 to rotate around the shaft portion 102a. As described above, the charge roller 102 is urged by the pressure spring 127b in a direction approaching the photosensitive drum 101 (the direction of arrow F). Here, the abutting portion 131b of the non-drive-side spacing member 131 abuts against the surface of the photosensitive drum 101. This restricts movement of the charge roller 102 in the direction approaching the photosensitive drum 101, and maintains a gap S between the surface of the photosensitive drum 101 and the abutting portion 102b of the charge roller 102. The abutting portion 131b is a protruding portion that protrudes in a direction intersecting the shaft portion 102a of the charge roller 102.

[0068] <Charging roller separation release configuration> Next, the separation release configuration of the charging roller 102 will be described with reference to Figures 12(a) to 12(c). Figures 12(a) to 12(c) are partial side views of the end of the charging unit 120 on the non-drive side. Although the non-drive side will be used for the description, the opposite drive side has a similar configuration.

[0069] 12(a) shows a state in which the photosensitive drum 101 rotates in the direction of arrow A and the release projection 124a of the drum flange 124 begins to engage with the engagement surface 131c of the non-drive-side spacing member 131. In this state, the abutment portion 131b of the non-drive-side spacing member 131 is still in abutment with the surface of the photosensitive drum 101. In addition, the elastic deformation portion 131d of the non-drive-side spacing member 131 is in contact with the wall portion 121b of the frame 121 and is deformed radially inward.

[0070] Figure 12(b) shows a state in which the photosensitive drum 101 has further rotated in the direction of arrow A from the state in Figure 12(a). When the engagement surface 131c is pressed by the release protrusion 124a, the non-drive-side spacing member 131 rotates around the cylindrical portion 131a in the direction of arrow P. At this time, the elastic deformation portion 131d is further deformed than in the state in Figure 12(a), thereby allowing the non-drive-side spacing member 131 to rotate.

[0071] When the non-drive side spacing member 131 rotates further from the state shown in FIG. 12(b), the state becomes one in which the separation is released as shown in FIG. 12(c). At this time, the abutting portion 13 of the non-drive side spacing member 131 1b of the charging roller 102 is moved to a position where it does not come into contact with the surface of the photosensitive drum 101. This allows the contact portion 102b of the charging roller 102 to come into contact with the surface of the photosensitive drum 101. The charging roller 102 is an example of a roller member that rotates while being in contact with the photosensitive drum 101 at the contact portion 102b during image formation.

[0072] <Configuration for holding the spacing member when assembling the charging unit> The structure for holding the spacing member when assembling the charging unit 120 will be described with reference to Fig. 1. Fig. 1 is a side view of the non-drive side of the charging unit 120 before the photosensitive drum 101 is assembled. Although the non-drive side will be used for the description, the opposite drive side has a similar structure.

[0073] The charging unit 120 in a state before the photosensitive drum 101 is assembled is the portion of the charging unit 120 excluding the photosensitive drum 101, and is an example of a roller holding unit that becomes part of the charging unit 120 when the photosensitive drum 101 is assembled. The portion of the charging unit 120 excluding the photosensitive drum 101 can also be said to be a roller holding unit that becomes part of the process cartridge 100 that is detachable from the image forming apparatus 1 when the photosensitive drum 101 is assembled.

[0074] The non-drive-side charge roller bearing 127a is held by a bearing mounting portion 121a, which is part of the frame 121, so as to be movable in a direction parallel to a first direction (arrow F direction), which is a direction in which the non-drive-side charge roller bearing 127a approaches the position where the photosensitive drum 101 is to be assembled. The first direction can also be said to be the direction opposite to the direction (arrow K direction) in which the photosensitive drum 101 is brought closer to the frame 121 when the photosensitive drum 101 is assembled. Furthermore, considering a state in which the photosensitive drum 101 is assembled to the charging unit 120, the non-drive-side charge roller bearing 127a can also be said to be held by the frame 121 (bearing mounting portion 121a) so as to be movable in a direction in which the distance from the photosensitive drum 101 changes. In this case, the first direction can also be said to be the direction in which the non-drive-side charge roller bearing 127a approaches the photosensitive drum 101. The non-drive-side charge roller bearing 127a is biased in the first direction (F direction) relative to the frame 121 by a pressure spring 127b, which serves as a first biasing member. The pressure spring 127b is provided between the non-drive side charging roller bearing 127a and the frame body 121.

[0075] Without the photosensitive drum 101, the charge roller 102 attempts to move in the biasing direction of the pressure spring 127b (the direction of arrow F). At this time, the movement restricting portion 121c of the frame 121 restricts the movement of the non-drive side charge roller bearing 127a, thereby restricting the movement of the charge roller 102 in the direction of arrow F. The structure in which the movement restricting portion 121c restricts the movement of the non-drive side charge roller bearing 127a will be described with reference to FIGS. 16, 17, and 18. FIG. 16 is an exploded perspective view of the non-drive side of the charging unit 120. FIG. 17 is a perspective view of the non-drive side of the charging unit 120. FIG. 18 is a cross-sectional view of the non-drive side charge roller bearing 127a of the charging unit 120 and its surrounding members, taken along a plane perpendicular to the rotation axis of the charge roller 102. The frame 121 has a bearing mounting portion 121a, and a movement restricting portion 121c, which is an engaging protrusion that protrudes toward the charge roller 102, is formed at the end of the bearing mounting portion 121a in the biasing direction (F direction) of the pressure spring 127b. The protrusion of the movement restricting portion 121c engages with an engaged portion 127c formed at the end of the non-drive-side charge roller bearing 127a in the F direction, thereby restricting movement of the non-drive-side charge roller bearing 127a in the F direction. As shown in FIGS. 1, 17, and 18, when the photosensitive drum 101 is not assembled to the charge roller 102, the movement restricting portion 121c of the bearing mounting portion 121a engages with the engaged portion 127c of the non-drive-side charge roller bearing 127a. This positions the non-drive-side charge roller bearing 127a at the first position. The position of the non-drive side charging roller bearing 127a shown in Figures 1, 17 and 18, where the end of the non-drive side charging roller bearing 127a is engaged with the movement restricting portion 121c, is defined as the first position. The first position is a position where the non-drive side charging roller bearing 127a is positioned when the photosensitive drum 101 is not assembled to the roller holding unit (charging unit 120). The restricting portion 121c is an example of a first restricting member that can restrict the non-drive side charging roller bearing 127a from moving in the first direction (the direction of the arrow F) from the first position.

[0076] In this state, the elastic deformation portion 131d of the non-drive-side spacing member 131 comes into contact with the wall portion 121b and elastically deforms, thereby receiving a force from the wall portion 121b. This force causes the non-drive-side spacing member 131 to rotate in the direction of arrow Q around the central axis of the cylindrical portion 131a. However, the locking surface 131f of the reverse rotation prevention portion 131e abuts against the wall portion 121b, restricting the rotation in the direction of arrow Q. As a result, the orientation of the non-drive-side spacing member 131 in the rotational direction is maintained by the frame 121, and the abutting portion 131b is maintained facing the direction of arrow K, which is the assembly direction of the photosensitive drum 101.

[0077] The non-drive-side spacing member 131 has a second protrusion 131g that protrudes from the cylindrical portion 131a in the radial direction of the shaft portion 102a. The elastic deformation portion 131d is an example of an arm portion that extends circumferentially of the cylindrical portion 131a with a gap between it and the surface of the cylindrical portion 131a and is elastically deformable in the radial direction. The elastic deformation portion 131d constitutes a second biasing member that can bias the non-drive-side spacing member 131 in a second direction (the direction of arrow Q), which is the rotational direction around the shaft portion 102a, relative to the frame 121. In the first embodiment, the elastic deformation portion 131d is an elastically deformable elastic portion provided on the non-drive-side spacing member 131. The position of the non-drive-side spacing member 131 shown in FIG. 1, where the reverse rotation prevention portion 131e abuts against the wall portion 121b, is defined as the second position. The second position is a position at which the non-drive-side spacing member 131 is positioned when the photosensitive drum 101 is not attached to the roller holding unit (charging unit 120). When the non-drive-side spacing member 131 is in the second position, the elastically deforming portion 131d abuts against the wall portion 121b of the frame 121 in an elastically deformed state, thereby applying a biasing force in the second direction (the direction of arrow Q) to the non-drive-side spacing member 131. When the non-drive-side spacing member 131 is in the second position, the radial distance between the surface of the cylindrical portion 131a and the inner wall 121d of the wall portion 121b of the frame 121 that faces the non-drive-side spacing member 131 is defined as D1 (FIG. 12(a)). The radial distance between the surface of the cylindrical portion 131a and the end 131h of the elastic deformation portion 131d when the elastic deformation portion 131d is not elastically deformed is defined as D2 (FIG. 12(c)). Distance D1 is narrower than distance D2. Therefore, when the non-drive-side spacing member 131 is in the second position, the end 131h of the elastic deformation portion 131d abuts against the inner wall 121d of the frame 121, causing the elastic deformation portion 131d to elastically deform radially inward. This generates an elastic force that urges the non-drive-side spacing member 131 in the second direction (direction Q).

[0078] The reverse rotation prevention portion 131e is an example of a second prevention member that can prevent the non-drive-side spacing member 131 from rotating in the second direction (the direction of arrow Q) from the second position. The reverse rotation prevention portion 131e is an example of a third protrusion that protrudes from the second protrusion 131g of the non-drive-side spacing member 131 in a direction different from that of the elastic deformation portion 131d. In the first embodiment, the reverse rotation prevention portion 131e abuts against the inner wall 121d of the wall portion 121b provided in the frame 121, thereby preventing the non-drive-side spacing member 131 from rotating in the second direction (the direction of arrow Q) from the second position. The wall portion 121b is an example of a second wall portion that abuts against the abutting portion to prevent the spacing member from rotating in the second direction from the second position.

[0079] As described above, the abutting portion 131b of the non-drive-side spacing member 131 protrudes in the first direction (the direction of arrow F) when the non-drive-side spacing member 131 is in the second position. As a result, when the photosensitive drum 101 is assembled to the charging unit 120, the abutting portion 131b is configured to come into contact with the surface of the photosensitive drum 101, so as to form a gap S between the photosensitive drum 101 and the charging roller 102.

[0080] 1 shows a state in which the photosensitive drum 101 is not assembled to the charging unit 120. In this state, the non-driving side charging roller bearing 127a is biased in the first direction by the pressure spring 127b. The non-drive-side spacing member 131 is biased in the direction indicated by the arrow F and is restricted in its movement in the first direction by the movement restricting portion 121c at the first position. The non-drive-side spacing member 131 is biased in the second direction (direction indicated by the arrow Q) by the elastic deformation portion 131d and is restricted in its movement in the second direction by the reverse rotation preventing portion 131e at the second position.

[0081] Since the non-drive side spacing member 131 is held in this position before the photosensitive drum 101 is assembled, there is no need for a worker or device to hold the position of the non-drive side spacing member 131 during the assembly process of assembling the photosensitive drum 101, resulting in good workability.

[0082] 12(a) shows a state after the photosensitive drum 101 has been assembled to the charging unit 120 and before the image forming apparatus 1 is operated for the first time. In this state, the non-drive-side charging roller bearing 127a is biased in a first direction (arrow F direction) by the pressure spring 127b and is at a position moved from the first position in the direction opposite to the first direction (arrow F direction) (arrow K direction). In addition, the non-drive-side spacing member 131 is biased in a second direction (arrow Q direction) by the elastic deformation portion 131d and is at the second position where its movement in the second direction is restricted by the reverse rotation prevention portion 131e.

[0083] 12(b) shows the state when the image forming apparatus 1 operates for the first time. The non-drive-side spacing member 131 has an engagement surface 131c (engagement portion), and the photosensitive drum 101 has a release protrusion 124a (engaged portion) that can engage with the engagement surface 131c. When the image forming apparatus 1 operates for the first time, the release protrusion 124a rotates while engaging with the engagement surface 131c, causing the non-drive-side spacing member 131 to rotate in the direction (arrow P direction) opposite to the second direction (arrow Q direction). When the non-drive-side spacing member 131 rotates from the second position in the direction opposite to the second direction to a position where the end 131h of the elastic deformation portion 131d is separated from the inner wall 121d, the elastic deformation portion 131d is no longer elastically deformed. At this time, the abutment portion 131b protrudes in a direction intersecting the first direction (direction F) and does not abut against the surface of the photosensitive drum 101, allowing the photosensitive drum 101 and the charging roller 102 to come into contact with each other. In this embodiment, the rotation angle from the state of FIG. 12(a) to the position where the end 131h of the elastic deformation portion 131d separates from the inner wall 121d is approximately 49 degrees. Note that this angle is merely an example, and is determined depending on the configuration of the non-drive-side spacing member 131 and the inner wall 121d of the frame body 121, and is not limited to this angle.

[0084] 12(c) shows the state after the image forming apparatus 1 has been operated for the first time. When the non-drive-side spacing member 131 rotates from the second position in the direction (arrow P direction) opposite to the second direction (arrow Q direction) to a position where the end 131h of the elastic deformation portion 131d is separated from the inner wall 121d, the abutting portion 131b protrudes in a direction intersecting with the first direction (arrow F direction). At this time, the abutting portion 131b does not abut against the surface of the photosensitive drum 101 assembled to the charging unit 120, allowing the photosensitive drum 101 and the charging roller 102 to come into contact with each other. The elastic deformation portion 131d is configured not to bias the non-drive-side spacing member 131 when the non-drive-side spacing member 131 rotates from the second position in the direction (arrow P direction) opposite to the second direction (arrow Q direction) to a position where the end 131h of the elastic deformation portion 131d is separated from the inner wall 121d.

[0085] 12(c), the non-drive-side charge roller bearing 127a is biased in the first direction (arrow F direction) by the pressure spring 127b and is at a position moved in the direction opposite to the first direction (arrow F direction) (arrow K direction) from the first position. Also, the non-drive-side spacing member 131 is at a position rotated in the direction opposite to the second direction (arrow P direction) from the second position to a position where the end 131h of the elastic deformation portion 131d is separated from the inner wall 121d and is not applying a biasing force from the elastic deformation portion 131d as the second biasing member.

[0086] The wall portion 121b with which the elastic deformation portion 131d and the locking surface 131f come into contact does not necessarily have to be the same. For example, as shown in FIG. 13, different wall portions 121b1 and 121b2 of the frame body 121 may be used. b2 may be in contact with each other.

[0087] 1 and the wall portions 121b1 and 121b2 shown in FIG. 13 are provided parallel to the first direction (arrow F direction), which is the moving direction of the charging roller 102, but this is not necessarily limited to this. It is sufficient that the elastic deformation portion 131d can apply a force to the non-drive-side spacing member 131 to rotate it in the second direction (arrow Q direction) by contacting while elastically deforming. It is also sufficient that the locking surface 131f can restrict the rotation of the non-drive-side spacing member 131 in the second direction (arrow Q direction) by contacting.

[0088] However, by providing the walls 121b, 121b1, and 121b2 parallel to the first direction (the direction of arrow F), which is the movement direction of the charging roller 102, it is possible to keep the deformation amount of the elastic deformation portion 131d constant regardless of the position of the charging roller 102. This makes it possible to stabilize the force that resists separation release, which is generated by the force received by the elastic deformation portion 131d.

[0089] Example 2 A second embodiment of the present invention will be described with reference to FIG. 14 is a partial side view of the end portion of the developing unit 250 according to the second embodiment, before the photosensitive drum is assembled. In the second embodiment, the developing roller 203 is used as a roller member for developing the electrostatic latent image formed on the photosensitive drum 101 into a toner image. The developing roller 203 is an example of a roller member that rotates while in contact with the photosensitive drum 101 during image formation. Note that the second embodiment has a configuration in which the charging roller 102 described in the first embodiment is replaced with the developing roller 203, and other configurations are substantially the same as those of the first embodiment. Therefore, in the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0090] As shown in FIG. 14, the non-drive side spacing member 131 is attached by fitting the cylindrical portion 131a onto the shaft portion 203a of the developing roller 203.

[0091] The structure for separating the developing roller 203, the structure for releasing the separation, and the structure for holding the separating member during assembly are the same as those in the first embodiment.

[0092] Example 3 A third embodiment of the present invention will be described with reference to FIG. FIG. 15 is a partial side view of the end of the transfer unit 350 according to the third embodiment before the photosensitive drum is assembled.

[0093] In the third embodiment, a transfer roller 306 for transferring a toner image (developer image) formed on the photosensitive drum 101 to a recording medium is used as a roller member. The transfer roller 306 is an example of a roller member that rotates while in contact with the photosensitive drum 101 during image formation. In the third embodiment, the charging roller 102 described in the first embodiment is replaced with the transfer roller 306, and other configurations are substantially the same as those in the first embodiment. Therefore, in the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0094] As shown in FIG. 15, the non-drive side spacing member 131 is attached by fitting the cylindrical portion 131a onto the shaft portion 306a of the transfer roller 306.

[0095] The separation structure of the transfer roller 306, the separation release structure, and the structure for holding the separation member during assembly are the same as those in the first embodiment.

[0096] In the above embodiment, the photosensitive drum 101 is assembled to form a charging unit, a developing unit, The configuration for maintaining the attitude of the spacing member in a roller holding unit constituting a part of a transfer unit or a process cartridge has been described. In the first embodiment, the charging unit 120 excluding the photosensitive drum 101 is an example of a roller holding unit that holds the charging roller 102 as a roller member. In the second embodiment, the developing unit 250 excluding the photosensitive drum 101 is an example of a roller holding unit that holds the developing roller 203 as a roller member. In the third embodiment, the transfer unit 350 excluding the photosensitive drum 101 is an example of a roller holding unit that holds the transfer roller 306 as a roller member. The charging unit 120, the developing unit 250, and the transfer unit 350 may constitute a cartridge that is detachable from the image forming apparatus 1. In this case, the cartridge excluding the photosensitive drum 101 is an example of a roller holding unit that holds the charging roller 102, the developing roller 203, and the transfer roller 306 as roller members. The charging unit 120, the developing unit 250, and the transfer unit 350 may constitute a part of the image forming apparatus 1. In this case, the portion of the image forming apparatus 1 excluding the photosensitive drum 101 is an example of a roller holding unit that holds the roller members, namely the charging roller 102, the developing roller 203, and the transfer roller 306. In other words, even in the roller holding unit that forms part of the image forming apparatus by assembling the photosensitive drum, it is possible to maintain the attitude of the spacing member in the state before the photosensitive drum is assembled, in a configuration similar to that of each of the above-described embodiments.

[0097] The present invention can also be understood as an image forming apparatus or cartridge in which the photosensitive drum 101 is assembled to the roller holding unit as described above. That is, the present invention includes the charging unit 120, developing unit 250, transfer unit 350, process cartridge 100, and image forming apparatus 1 as a roller holding unit in a state before the photosensitive drum 101 is assembled, as shown in FIG. 1 . The present invention also includes the charging unit 120, developing unit 250, transfer unit 350, process cartridge 100, and image forming apparatus 1 as a roller holding unit in a state before the photosensitive drum 101 is assembled, as shown in FIG. 12( a). In either configuration, as described in the above embodiment, by providing a structure that restricts movement of the spacing member in the first direction and a structure that restricts movement in the second direction, the orientation of the spacing member can be maintained in a state before the photosensitive drum 101 is assembled. After the photosensitive drum 101 is assembled, the photosensitive drum 101 and the roller members (the charging roller 102, the developing roller 203, and the transfer roller 306) can be held in a spaced-apart state. This improves the workability of the process of assembling the photosensitive drum 101 into the roller holding unit (the charging unit 120, the developing unit 250, the transfer unit 350, the process cartridge 100, and the image forming apparatus 1). Furthermore, it is possible to prevent the photosensitive drum 101 and the roller members from continuing to come into contact with each other until the first operation of the image forming apparatus 1, thereby preventing contact marks from being left behind.

[0098] The disclosure of this embodiment includes the following configuration. (Configuration 1) A roller holding unit that forms a part of an image forming apparatus or a part of a cartridge that is detachable from a main body of an image forming apparatus by assembling a photosensitive drum, A frame body, a roller member having a shaft portion and rotating in contact with the photosensitive drum during image formation; a bearing member that rotatably supports the shaft portion, the bearing member being held by the frame so as to be movable in a first direction that is a direction perpendicular to the rotation axis of the shaft portion; a first biasing member that biases the bearing member in the first direction relative to the frame; a first restricting member configured to restrict movement of the bearing member in the first direction from a first position, which is a position at which the bearing member is positioned when the photosensitive drum is not assembled to the roller holding unit; and a spacing member rotatable about the shaft; The spacing member can be biased relative to the frame in a second direction, which is a rotation direction around the shaft portion. a second biasing member configured as a a second restricting member configured to restrict the spacing member from rotating in the second direction, The spacing member has a cylindrical portion attached to an axial end of the shaft portion, and a protruding portion protruding from the cylindrical portion in a radial direction of the shaft portion. A roller holding unit characterized by: (Configuration 2) The second biasing member is a second protruding portion protruding from the cylindrical portion of the spacing member in a radial direction of the shaft portion; and an arm portion extending along the circumferential direction of the cylindrical portion with a gap between the second protruding portion and a surface of the cylindrical portion, the arm portion being elastically deformable in the radial direction, When the position at which the spacing member is positioned in a state in which the photosensitive drum is not assembled to the roller holding unit is defined as a second position, a radial distance between a surface of the cylindrical portion and an inner wall of the frame that faces the spacing member when the spacing member is in the second position is narrower than a radial distance between the surface of the cylindrical portion and an end of the arm portion when the arm portion is not elastically deformed, when the spacing member is in the second position, the ends of the arms abut against the inner wall of the frame, causing the arms to elastically deform radially inward, thereby generating an elastic force that urges the spacing member in the second direction, The second restricting member is a third protrusion protruding from the second protrusion of the spacing member in a direction different from that of the arm portion, the third protrusion is configured to be able to restrict rotation of the spacing member in the second direction by contacting the inner wall of the frame body, the protrusion is configured to protrude in the first direction when the spacing member is in the second position, and to come into contact with the surface of the photosensitive drum when the photosensitive drum is assembled to the roller holding unit, thereby forming a gap between the photosensitive drum and the roller member; When the photosensitive drum is not assembled to the roller holding unit, the bearing member is biased in the first direction by the first biasing member and is restricted in its movement in the first direction at the first position by the first restricting member, The roller holding unit described in configuration 1 is characterized in that the spacing member is biased in the second direction by the second biasing member and its movement in the second direction is restricted at the second position by the second regulating member. (Configuration 3) After the photosensitive drum is assembled to the roller holding unit and before the image forming apparatus is operated for the first time, the bearing member is at a position moved from the first position in a direction opposite to the first direction while being biased in the first direction by the first biasing member, The roller holding unit according to configuration 2, wherein the spacing member is biased in the second direction by the second biasing member and is restricted in its movement in the second direction at the second position by the second regulating member. (Configuration 4) when the spacing member rotates from the second position in a direction opposite to the second direction to a position where the end of the arm portion of the second urging member is separated from the inner wall of the frame body and the arm portion is no longer elastically deformed, the protrusion protrudes in a direction intersecting the first direction and does not come into contact with the surface of the photosensitive drum when the photosensitive drum is assembled to the roller holding unit, allowing contact between the photosensitive drum and the roller member, the spacing member has an engaging portion, the photosensitive drum has an engaged portion that can be engaged with the engaging portion, When the image forming apparatus is operated for the first time, the engaged portion rotates while engaging with the engaging portion. rotating the spacing member in a direction opposite to the second direction; In a state after the image forming apparatus has been operated for the first time, the bearing member is at a position moved from the first position in a direction opposite to the first direction while being biased in the first direction by the first biasing member, The roller retaining unit according to configuration 2 or 3, wherein the spacing member is in a position rotated from the second position in a direction opposite to the second direction while not being biased by the second biasing member until the end of the arm portion of the second biasing member is separated from the inner wall of the frame body. (Configuration 5) 5. The roller holder unit according to any one of configurations 1 to 4, wherein the first biasing member is a spring provided between the bearing member and the frame. (Configuration 6) 6. The roller holding unit according to any one of configurations 1 to 5, wherein the first regulating member is an engaging protrusion that engages with an end of the bearing member in the first direction. (Configuration 7) 7. The roller holding unit according to any one of configurations 1 to 6, wherein the roller member is a charging roller that charges the photosensitive drum. (Configuration 8) 7. The roller holding unit according to any one of configurations 1 to 6, wherein the roller member is a developing roller that develops an electrostatic latent image formed on the photosensitive drum into a toner image. (Configuration 9) 7. The roller holding unit according to any one of configurations 1 to 6, wherein the roller member is a transfer roller that transfers a toner image formed on the photosensitive drum onto a recording medium. (Configuration 10) An image forming apparatus, A frame body, A photosensitive drum; a roller member having a shaft portion and rotating in contact with the photosensitive drum during image formation; a bearing member that rotatably supports the shaft portion, the bearing member being held by the frame body so as to be movable in a direction in which a distance from the photosensitive drum changes; a first biasing member that biases the bearing member relative to the frame body in a first direction that is a direction toward the photosensitive drum; a first restricting member configured to restrict movement of the bearing member in the first direction from a first position where the bearing member is positioned when the photosensitive drum is not assembled in the image forming apparatus; and a spacing member rotatable about the shaft; a second biasing member configured to bias the spacing member relative to the frame body in a second direction, which is a rotation direction around the shaft portion; a second restricting member configured to restrict the spacing member from rotating in the second direction, The spacing member has a cylindrical portion attached to an axial end of the shaft portion, and a protruding portion protruding from the cylindrical portion in a radial direction of the shaft portion. An image forming apparatus characterized by: (Configuration 11) The second biasing member is a second protruding portion protruding from the cylindrical portion of the spacing member in a radial direction of the shaft portion; and an arm portion extending along the circumferential direction of the cylindrical portion with a gap between the second protruding portion and a surface of the cylindrical portion, the arm portion being elastically deformable in the radial direction, When the position at which the spacing member is positioned in a state in which the photosensitive drum is not assembled in the image forming apparatus is defined as a second position, When the spacing member is in the second position, the surface of the cylindrical portion and the front surface of the frame body a radial distance between the inner wall facing the spacing member and the arm portion is narrower than a radial distance between a surface of the cylindrical portion and an end of the arm portion when the arm portion is not elastically deformed, when the spacing member is in the second position, the ends of the arms abut against the inner wall of the frame, causing the arms to elastically deform radially inward, thereby generating an elastic force that urges the spacing member in the second direction, The second restricting member is a third protrusion protruding from the second protrusion of the spacing member in a direction different from that of the arm portion, the third protrusion is configured to be able to restrict rotation of the spacing member in the second direction by contacting the inner wall of the frame body, the protrusion protrudes in the first direction when the spacing member is in the second position and abuts against the surface of the photosensitive drum to form a gap between the photosensitive drum and the roller member; In a state before the image forming apparatus is operated for the first time, the bearing member is at a position moved from the first position in a direction opposite to the first direction while being biased in the first direction by the first biasing member, The image forming apparatus described in configuration 10, characterized in that the spacing member is in a state where movement in the second direction is restricted at the second position by the second regulating member while being urged in the second direction by the second urging member. (Configuration 12) when the spacing member rotates from the second position in a direction opposite to the second direction to a position where the end of the arm portion of the second urging member is separated from the inner wall of the frame body and the arm portion is no longer elastically deformed, the protrusion protrudes in a direction intersecting the first direction and does not come into contact with the surface of the photosensitive drum, allowing the photosensitive drum and the roller member to come into contact with each other, the spacing member has an engaging portion, the photosensitive drum has an engaged portion that can be engaged with the engaging portion, When the image forming apparatus is operated for the first time, the engaged portion rotates while engaging with the engaging portion, thereby rotating the spacing member in a direction opposite to the second direction; In a state after the image forming apparatus has been operated for the first time, the bearing member is at a position moved from the first position in a direction opposite to the first direction while being biased in the first direction by the first biasing member, The image forming apparatus of configuration 11, wherein the spacing member is in a position rotated from the second position in a direction opposite to the second direction when not biased by the second biasing member until the end of the arm portion of the second biasing member is separated from the inner wall of the frame body. (Configuration 13) A cartridge detachably mountable to a main body of an image forming apparatus, A frame body, A photosensitive drum; a roller member having a shaft portion and rotating in contact with the photosensitive drum during image formation; a bearing member that rotatably supports the shaft portion, the bearing member being held by the frame body so as to be movable in a direction in which a distance from the photosensitive drum changes; a first biasing member that biases the bearing member relative to the frame body in a first direction that is a direction toward the photosensitive drum; a first restricting member configured to restrict movement of the bearing member in the first direction from a first position at which the bearing member is positioned when the photosensitive drum is not assembled in the cartridge; a spacing member rotatable about the shaft; a second biasing member configured to bias the spacing member relative to the frame body in a second direction, which is a rotation direction around the shaft portion; a second restricting member configured to restrict the spacing member from rotating in the second direction, The spacing member has a cylindrical portion attached to an axial end of the shaft portion, and a protruding portion protruding from the cylindrical portion in a radial direction of the shaft portion. A cartridge characterized by: (Configuration 14) The second biasing member is a second protruding portion protruding from the cylindrical portion of the spacing member in a radial direction of the shaft portion; and an arm portion extending along the circumferential direction of the cylindrical portion with a gap between the second protruding portion and a surface of the cylindrical portion, the arm portion being elastically deformable in the radial direction, When the position at which the spacing member is positioned in a state in which the photosensitive drum is not assembled in the cartridge is defined as a second position, a radial distance between a surface of the cylindrical portion and an inner wall of the frame that faces the spacing member when the spacing member is in the second position is narrower than a radial distance between the surface of the cylindrical portion and an end of the arm portion when the arm portion is not elastically deformed, when the spacing member is in the second position, the ends of the arms abut against the inner wall of the frame, causing the arms to elastically deform radially inward, thereby generating an elastic force that urges the spacing member in the second direction, The second restricting member is a third protrusion protruding from the cylindrical portion of the spacing member in a radial direction of the shaft portion in a direction different from that of the second protrusion, the third protrusion is configured to be able to restrict rotation of the spacing member in the second direction by contacting the inner wall of the frame body, the protrusion protrudes in the first direction when the spacing member is in the second position and abuts against the surface of the photosensitive drum to form a gap between the photosensitive drum and the roller member; In a state before the cartridge mounted in the apparatus main body is operated for the first time, the bearing member is at a position moved from the first position in a direction opposite to the first direction while being biased in the first direction by the first biasing member, The cartridge described in configuration 13 is characterized in that the spacing member is biased in the second direction by the second biasing member and its movement in the second direction is restricted at the second position by the second regulating member. (Configuration 15) when the spacing member rotates from the second position in a direction opposite to the second direction to a position where the end of the arm portion of the second urging member is separated from the inner wall of the frame body and the arm portion is no longer elastically deformed, the protrusion protrudes in a direction intersecting the first direction and does not come into contact with the surface of the photosensitive drum, allowing the photosensitive drum and the roller member to come into contact with each other, the spacing member has an engaging portion, the photosensitive drum has an engaged portion that can be engaged with the engaging portion, When the image forming apparatus is operated for the first time, the engaged portion rotates while engaging with the engaging portion, thereby rotating the spacing member in a direction opposite to the second direction; In a state after the cartridge attached to the main body of the apparatus has been operated for the first time, the bearing member is at a position moved from the first position in a direction opposite to the first direction while being biased in the first direction by the first biasing member, A cartridge according to configuration 14, wherein the spacing member is in a position rotated from the second position in a direction opposite to the second direction when not biased by the second biasing member until the end of the arm portion of the second biasing member is separated from the inner wall of the frame body. [Explanation of symbols]

[0099] 1: image forming apparatus, 2: apparatus main body, 100: process cartridge, 101: photosensitive drum, 102: charging roller, 102a: shaft portion, 120: charging unit, 121: frame body, 121b: wall portion, 121c: movement regulating portion, 126a: driving side charging roller bearing, 126b: pressure spring, 127a: non-driving side charging roller bearing, 127b: pressure spring, 130: driving side spacing member 131: non-drive side spacing member, 131b: abutment portion, 131d: elastic deformation portion, 131e: reverse rotation prevention portion

Claims

1. A roller holding unit that forms a part of an image forming apparatus or a part of a cartridge that is detachable from a main body of an image forming apparatus by assembling a photosensitive drum, A frame body, a roller member having a shaft portion and rotating in contact with the photosensitive drum during image formation; a bearing member that rotatably supports the shaft portion, the bearing member being held by the frame so as to be movable in a first direction that is a direction perpendicular to the rotation axis of the shaft portion; a first biasing member that biases the bearing member in the first direction relative to the frame body; a first restricting member configured to restrict movement of the bearing member in the first direction from a first position where the bearing member is positioned when the photosensitive drum is not assembled to the roller holding unit; a spacing member rotatable about the shaft; a second biasing member configured to bias the spacing member relative to the frame body in a second direction, which is a rotation direction around the shaft portion; a second restricting member configured to restrict the spacing member from rotating in the second direction, The spacing member has a cylindrical portion attached to an axial end of the shaft portion, and a protruding portion protruding from the cylindrical portion in a radial direction of the shaft portion. A roller holding unit characterized by:

2. The second biasing member is a second protruding portion protruding from the cylindrical portion of the spacing member in a radial direction of the shaft portion; and an arm portion extending along the circumferential direction of the cylindrical portion with a gap between the second protruding portion and a surface of the cylindrical portion, the arm portion being elastically deformable in the radial direction, When the position at which the spacing member is positioned in a state in which the photosensitive drum is not assembled to the roller holding unit is defined as a second position, a radial distance between a surface of the cylindrical portion and an inner wall of the frame body facing the spacing member when the spacing member is in the second position is narrower than a radial distance between the surface of the cylindrical portion and an end of the arm portion when the arm portion is not elastically deformed, when the spacing member is in the second position, the ends of the arms abut against the inner wall of the frame, causing the arms to elastically deform radially inward, thereby generating an elastic force that urges the spacing member in the second direction, The second restricting member is a third protrusion protruding from the second protrusion of the spacing member in a direction different from that of the arm portion; the third protrusion is configured to abut against the inner wall of the frame body, thereby restricting rotation of the spacing member in the second direction, the protrusion is configured to protrude in the first direction when the spacing member is in the second position, and to come into contact with the surface of the photosensitive drum when the photosensitive drum is assembled to the roller holding unit, thereby forming a gap between the photosensitive drum and the roller member; When the photosensitive drum is not assembled to the roller holding unit, the bearing member is biased in the first direction by the first biasing member and is restricted in movement in the first direction at the first position by the first restricting member, 2. The roller holding unit according to claim 1, wherein the spacing member is biased in the second direction by the second biasing member and is restricted in its movement in the second direction at the second position by the second regulating member.

3. After the photosensitive drum is assembled to the roller holding unit and before the image forming apparatus is operated for the first time, the bearing member is at a position moved from the first position in a direction opposite to the first direction while being biased in the first direction by the first biasing member, 3. The roller holding unit according to claim 2, wherein the spacing member is biased in the second direction by the second biasing member and is restricted in its movement in the second direction at the second position by the second regulating member.

4. when the spacing member rotates from the second position in a direction opposite to the second direction to a position where the end of the arm portion of the second urging member is separated from the inner wall of the frame body and the arm portion is no longer elastically deformed, the protrusion protrudes in a direction intersecting the first direction and does not come into contact with the surface of the photosensitive drum when the photosensitive drum is assembled to the roller holding unit, allowing contact between the photosensitive drum and the roller member, the spacing member has an engaging portion, the photosensitive drum has an engaged portion that can be engaged with the engaging portion, When the image forming apparatus is operated for the first time, the engaged portion rotates while engaging with the engaging portion, thereby rotating the spacing member in a direction opposite to the second direction; In a state after the image forming apparatus has been operated for the first time, the bearing member is at a position moved from the first position in a direction opposite to the first direction while being biased in the first direction by the first biasing member, 4. The roller retaining unit according to claim 2, wherein the spacing member is in a position rotated from the second position in a direction opposite to the second direction when not biased by the second biasing member until the end of the arm portion of the second biasing member is separated from the inner wall of the frame body.

5. 4. The roller holder unit according to claim 1, wherein the first biasing member is a spring provided between the bearing member and the frame body.

6. 4. The roller holder unit according to claim 1, wherein the first regulating member is an engaging protrusion that engages with an end of the bearing member in the first direction.

7. 4. The roller holding unit according to claim 1, wherein the roller member is a charging roller that charges the photosensitive drum.

8. 4. The roller holding unit according to claim 1, wherein the roller member is a developing roller that develops an electrostatic latent image formed on the photosensitive drum into a toner image.

9. 4. The roller holding unit according to claim 1, wherein the roller member is a transfer roller that transfers a toner image formed on the photosensitive drum onto a recording medium.

10. An image forming apparatus, A frame body, A photosensitive drum; a roller member having a shaft portion and rotating in contact with the photosensitive drum during image formation; a bearing member that rotatably supports the shaft portion, the bearing member being held by the frame body so as to be movable in a direction in which a distance from the photosensitive drum changes; a first biasing member that biases the bearing member relative to the frame body in a first direction that is a direction toward the photosensitive drum; a first restricting member configured to restrict movement of the bearing member in the first direction from a first position where the bearing member is positioned when the photosensitive drum is not assembled in the image forming apparatus; and a spacing member rotatable about the shaft; The spacing member can be biased relative to the frame in a second direction, which is a rotation direction around the shaft portion. a second biasing member configured as a a second restricting member configured to restrict the spacing member from rotating in the second direction, The spacing member has a cylindrical portion attached to an axial end of the shaft portion, and a protruding portion protruding from the cylindrical portion in a radial direction of the shaft portion. An image forming apparatus characterized by:

11. The second biasing member is a second protruding portion protruding from the cylindrical portion of the spacing member in a radial direction of the shaft portion; and an arm portion extending along the circumferential direction of the cylindrical portion with a gap between the second protruding portion and a surface of the cylindrical portion, the arm portion being elastically deformable in the radial direction, When the position at which the spacing member is positioned in a state in which the photosensitive drum is not assembled in the image forming apparatus is defined as a second position, a radial distance between a surface of the cylindrical portion and an inner wall of the frame body facing the spacing member when the spacing member is in the second position is narrower than a radial distance between the surface of the cylindrical portion and an end of the arm portion when the arm portion is not elastically deformed, when the spacing member is in the second position, the ends of the arms abut against the inner wall of the frame, causing the arms to elastically deform radially inward, thereby generating an elastic force that urges the spacing member in the second direction, The second restricting member is a third protrusion protruding from the second protrusion of the spacing member in a direction different from that of the arm portion; the third protrusion is configured to abut against the inner wall of the frame body, thereby restricting rotation of the spacing member in the second direction, the protrusion protrudes in the first direction when the spacing member is in the second position and abuts against the surface of the photosensitive drum to form a gap between the photosensitive drum and the roller member; In a state before the image forming apparatus is operated for the first time, the bearing member is at a position moved from the first position in a direction opposite to the first direction while being biased in the first direction by the first biasing member, 11. The image forming apparatus according to claim 10, wherein the spacing member is biased in the second direction by the second biasing member and is restricted in its movement in the second direction at the second position by the second restricting member.

12. when the spacing member rotates from the second position in a direction opposite to the second direction to a position where the end of the arm portion of the second urging member is separated from the inner wall of the frame body and the arm portion is no longer elastically deformed, the protrusion protrudes in a direction intersecting the first direction and does not come into contact with the surface of the photosensitive drum, allowing the photosensitive drum and the roller member to come into contact with each other, the spacing member has an engaging portion, the photosensitive drum has an engaged portion that can be engaged with the engaging portion, When the image forming apparatus is operated for the first time, the engaged portion rotates while engaging with the engaging portion, thereby rotating the spacing member in a direction opposite to the second direction; In a state after the image forming apparatus has been operated for the first time, the bearing member is at a position moved from the first position in a direction opposite to the first direction while being biased in the first direction by the first biasing member, 12. The image forming apparatus according to claim 11, wherein the spacing member is in a position rotated from the second position in a direction opposite to the second direction when not biased by the second biasing member until the end of the arm portion of the second biasing member is separated from the inner wall of the frame body.

13. A cartridge detachably mountable to a main body of an image forming apparatus, A frame body, A photosensitive drum; a roller member having a shaft portion and rotating in contact with the photosensitive drum during image formation; a bearing member that rotatably supports the shaft portion, the bearing member being held by the frame body so as to be movable in a direction in which a distance from the photosensitive drum changes; a first biasing member that biases the bearing member relative to the frame body in a first direction that is a direction toward the photosensitive drum; a first restricting member configured to restrict movement of the bearing member in the first direction from a first position at which the bearing member is positioned when the photosensitive drum is not assembled in the cartridge; a spacing member rotatable about the shaft; a second biasing member configured to bias the spacing member relative to the frame body in a second direction, which is a rotation direction around the shaft portion; a second restricting member configured to restrict the spacing member from rotating in the second direction, The spacing member has a cylindrical portion attached to an axial end of the shaft portion, and a protruding portion protruding from the cylindrical portion in a radial direction of the shaft portion. A cartridge characterized by:

14. The second biasing member is a second protruding portion protruding from the cylindrical portion of the spacing member in a radial direction of the shaft portion; and an arm portion extending along the circumferential direction of the cylindrical portion with a gap between the second protruding portion and a surface of the cylindrical portion, the arm portion being elastically deformable in the radial direction, When the position at which the spacing member is positioned in a state in which the photosensitive drum is not assembled in the cartridge is defined as a second position, a radial distance between a surface of the cylindrical portion and an inner wall of the frame body facing the spacing member when the spacing member is in the second position is narrower than a radial distance between the surface of the cylindrical portion and an end of the arm portion when the arm portion is not elastically deformed, when the spacing member is in the second position, the ends of the arms abut against the inner wall of the frame, causing the arms to elastically deform radially inward, thereby generating an elastic force that urges the spacing member in the second direction, The second restricting member is a third protrusion protruding from the cylindrical portion of the spacing member in a radial direction of the shaft portion in a direction different from that of the second protrusion, the third protrusion is configured to abut against the inner wall of the frame body, thereby restricting rotation of the spacing member in the second direction, the protrusion protrudes in the first direction when the spacing member is in the second position and abuts against the surface of the photosensitive drum to form a gap between the photosensitive drum and the roller member; In a state before the cartridge mounted in the apparatus main body is operated for the first time, the bearing member is at a position moved from the first position in a direction opposite to the first direction while being biased in the first direction by the first biasing member, The cartridge according to claim 13, wherein the spacing member is in a state where movement in the second direction is restricted by the second restricting member at the second position while being urged in the second direction by the second urging member.

15. when the spacing member rotates from the second position in a direction opposite to the second direction to a position where the end of the arm portion of the second urging member is separated from the inner wall of the frame body and the arm portion is no longer elastically deformed, the protrusion protrudes in a direction intersecting the first direction and does not come into contact with the surface of the photosensitive drum, allowing the photosensitive drum and the roller member to come into contact with each other, the spacing member has an engaging portion, the photosensitive drum has an engaged portion that can be engaged with the engaging portion, When the image forming apparatus is operated for the first time, the engaged portion rotates while engaging with the engaging portion, thereby rotating the spacing member in a direction opposite to the second direction; In a state after the cartridge attached to the main body of the apparatus has been operated for the first time, the bearing member is at a position moved from the first position in a direction opposite to the first direction while being biased in the first direction by the first biasing member, The cartridge according to claim 14, wherein the spacing member is in a position rotated from the second position in a direction opposite to the second direction when not biased by the second biasing member until the end of the arm portion of the second biasing member is separated from the inner wall of the frame body.

Images