Process unit

Abstract

A technology is provided that can achieve both weight reduction and safety for a frame that supports a process means. [Solution] A cartridge for use in an image forming device, comprising: a process means used for image formation; a first member made of a first resin material; a second member made of a second resin material having higher flame retardancy than the first resin material; and an electrode member having a contact portion powered by the main body of the image forming device and electrically connecting the main body of the device and the process means; characterized in that the density of the second resin material in the second member is greater than the density of the first resin material in the first member, and the contact portion is arranged in the vicinity of the first member and the second member, and is arranged closer to the second member than the first member.

Description

[Technical Field]

[0001] This invention relates to a cartridge and an image forming apparatus using the same. [Background technology]

[0002] In an electrophotographic image forming apparatus employing a process cartridge system, the main body electrodes of the apparatus and the electrode members of the cartridge come into contact when the cartridge is mounted on the apparatus body, and conductive members such as process means provided on the cartridge are electrically connected to the apparatus body. As an example of an electrode member, Patent Document 1 describes a configuration in which a conductive resin is assembled to the frame that constitutes the cartridge. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2012-63750 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, in the conventional example described above, in order to attach the conductive part to the frame, if a conductive resin or metal plate was used as the conductive part, it was necessary to use a resin (flame-retardant material) with high flame-retardant properties for the frame in order to ensure electrical safety near the conductive part. The use of flame-retardant material limited the choice of materials, which was a particular challenge in reducing the weight of the frame components.

[0005] Therefore, the objective of the present invention is to provide a technology that can achieve both weight reduction and safety for the frame supporting the process means. [Means for solving the problem]

[0006] To solve the above problems, the invention of this application is: A cartridge used in an image forming apparatus, Processes and means used in image formation, A first member made of a first resin material, A second member made of a second resin material having higher flame retardancy than the first resin material, An electrode member having a contact portion that is powered by the main body of the image forming apparatus, and electrically connecting the main body of the apparatus and the process means, In a cartridge having, The density of the second resin material in the second member is greater than the density of the first resin material in the first member. The contact portion is disposed in the vicinity of the first member and the second member, and is characterized in that it is disposed closer to the second member than to the first member. Furthermore, in order to solve the above problems, the invention of this application is, A cartridge used in an image forming apparatus, Processes and means used in image formation, A first member made of a first resin material, A second member made of a second resin material having higher flame retardancy than the first resin material, An electrode member having a contact portion that is powered by the main body of the image forming apparatus, and electrically connecting the main body of the apparatus and the process means, In a cartridge having, The density of the second resin material in the second member is the same as the density of the first resin material in the first member. Greater than the density of the resin material, The contact portion is characterized by being disposed on the second member. Furthermore, in order to solve the above problems, the invention of this application is, A cartridge used in an image forming apparatus, Processes and means used in image formation, A first member made of a first resin material, A second member made of a second resin material having higher flame retardancy than the first resin material, It has a contact portion that is supplied with power from the apparatus main body of the image forming apparatus, and an electrode member that electrically connects the apparatus main body and the process means. In a cartridge having the density of the second resin material in the second member is greater than the density of the first resin material in the first member. When the contact portion becomes a source of ignition due to power being supplied from the apparatus main body to the electrode member, the second member is arranged so that the second member self-extinguishes without the first member igniting.

Advantages of the Invention

[0007] According to the present invention, it is possible to achieve both weight reduction and safety of the frame body that supports the process means.

Brief Description of the Drawings

[0008] [Figure 1] Exploded view of the developing contact configuration in Example 1 [Figure 2] Cross-sectional view of the image forming apparatus main body and the cartridge in Example 1 [Figure 3] Cross-sectional view of the cartridge in Example 1 [Figure 4] Perspective view for explaining the configuration of the cartridge in Example 1 [Figure 5] Perspective view for explaining the configuration of the cleaning unit in Example 1 [Figure 6] Cross-sectional view for explaining the mounting of the cartridge in Example 1 [Figure 7] Cross-sectional view for explaining the positioning of the cartridge in Example 1 [Figure 8] Perspective view for explaining the attachment and detachment of the cartridge in Example 1 [Figure 9] Perspective view for explaining the configuration of the cartridge in Example 1 [Figure 10] Exploded perspective view of the charging contact configuration of the cartridge in Example 1 [Figure 11] Explanatory view of the developing contact configuration of the cartridge in Example 1 [Figure 12] Diagram illustrating the electrostatic contact configuration of the cartridge in Example 1. [Figure 13] Explanatory diagram illustrating the conductive bearing member in Example 1 [Figure 14] Enlarged view illustrating the conductive part in Example 1 [Figure 15] Exploded perspective view of the developing unit in Example 2 [Figure 16] Schematic diagram of the image forming apparatus in Example 2 [Figure 17] Cross-sectional view of the cartridge in Example 2 [Figure 18] Perspective view of the cartridge in Example 2 [Figure 19] Perspective view of the developing unit in Example 2 [Figure 20] Diagram illustrating the developing unit in Example 2 [Figure 21] Exploded perspective view of the cleaning unit in Example 2 [Figure 22] Diagram illustrating the cleaning unit in Example 2 [Figure 23] Schematic cross-sectional view of the image forming apparatus in Example 3 [Figure 24] Cross-sectional view of the cartridge in Example 3 [Figure 25] Cross-sectional view of the image forming apparatus in Example 3 [Figure 26] Cross-sectional view of the image forming apparatus in Example 3 [Figure 27] Cross-sectional view of the image forming apparatus in Example 3 [Figure 28] Exploded perspective view of the drum unit in Example 3 [Figure 29] Exploded perspective view of the developing unit in Example 3 [Figure 30] Exploded perspective view of the cartridge in Example 3 [Figure 31] Assembly perspective view of the cartridge in Example 3 [Figure 32(a)] Perspective view of the cartridge and non-driven cartridge cover member in Example 3 [Figure 32(b)] Cross-sectional view of the non-drive side cartridge cover member in Example 3 [Figure 32(c)] Cross-sectional view of the cartridge and non-driven cartridge cover member in Example 3 [Figure 32(d)] Cross-sectional view of the cartridge and non-driven cartridge cover member in Example 3 [Figure 33(a)] Perspective view of the memory element communication unit and contact spring retaining member in Example 3 [Figure 33(b)] Enlarged view of the memory element communication unit and contact spring retaining member in Example 3 [Figure 33(c)] Enlarged view of the memory element communication unit and contact spring retaining member in Example 3 [Figure 34] A perspective view of the cleaning frame, showing key points of the electrostatic contact configuration in a modified example of Example 1. [Figure 35] An exploded perspective view showing key parts of the electrostatic contact configuration in a modified example of Example 1. [Figure 36] Diagram illustrating the electrostatic contact configuration in a modified example of Example 1. [Modes for carrying out the invention]

[0009] The best mode for carrying out this invention will be described in detail below with reference to the drawings and embodiments. However, the functions, materials, shapes, and relative arrangements of the components described in these embodiments are not intended to limit the scope of this invention to those unless otherwise specified.

[0010] <Example 1> Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The rotation axis direction of the electrophotographic photosensitive drum is defined as the longitudinal direction. Furthermore, in the longitudinal direction, the side on which the electrophotographic photosensitive drum receives driving force from the image forming apparatus body is defined as the driving side, and the opposite side is defined as the non-driving side. The overall configuration and image forming process will be described using Figures 2 and 3. Figure 2 is a cross-sectional view of the apparatus body (electrophotographic image forming apparatus body, image forming apparatus body) A and process cartridge B of an electrophotographic image forming apparatus according to one embodiment of the present invention. Figure 3 is a cross-sectional view of process cartridge B. Here, a process cartridge is a cartridge in which a photosensitive element and a process means that acts on the photosensitive element are integrally formed and detachably attached to the electrophotographic image forming apparatus body. For example, a cartridge may be formed in which a photosensitive element and at least one of the process means, such as a developing means, a charging means, and a cleaning means, are integrally formed. Furthermore, an electrophotographic image forming apparatus is one that forms an image on a recording medium using an electrophotographic image forming method. Examples of electrophotographic image forming apparatus include, for example, electrophotographic copiers, electrophotographic printers (LED printers, laser beam printers, etc.), facsimile machines, and word processors. Apparatus A refers to the part of the electrophotographic image forming apparatus excluding process cartridge B (hereinafter referred to as cartridge B).

[0011] [Overall configuration of an electrophotographic image forming apparatus] The electrophotographic image forming apparatus (image forming apparatus) shown in Figure 2 is a laser beam printer utilizing electrophotographic technology in which cartridge B is detachably attached to the apparatus body A. When cartridge B is mounted on the apparatus body A, an exposure apparatus 3 (laser scanner unit) is positioned to form a latent image on the electrophotographic photosensitive drum 62, which serves as the image carrier for cartridge B. Also, a recording medium (hereinafter referred to as sheet material PA) to be image-formed is located below cartridge B. A sheet tray 4 containing an electrophotographic photosensitive drum 62 is positioned on the device. The electrophotographic photosensitive drum 62 is an electrophotographic photosensitive drum used for forming electrophotographic images. Furthermore, the main body A of the device has a pickup roller 5a, a pair of feed rollers 5b, a transfer guide 6, a transfer roller 7, a transport guide 8, a fixing device 9, a pair of discharge rollers 10, a discharge tray 11, etc. arranged sequentially along the transport direction D of the sheet material PA. The fixing device 9 is composed of a heating roller 9a and a pressure roller 9b.

[0012] <Image Formation Process> Next, the outline of the image formation process will be described. Based on the print start signal, the electrophotographic photosensitive drum (hereinafter referred to as the photosensitive drum 62 or simply the drum 62) is driven to rotate at a predetermined peripheral speed (process speed) in the direction of arrow R. A charging roller (charging member) 66 to which a bias voltage is applied contacts the outer surface of the drum 62, and the outer surface of the drum 62 is uniformly charged (see Figure 3). The exposure apparatus 3 outputs a laser beam L corresponding to the image information. This laser beam L passes through the laser aperture 71h (see Figure 2) provided in the cleaning frame 71 of the cartridge B, and scans and exposes the outer surface of the drum 62. As a result, an electrostatic latent image corresponding to the image information is formed on the outer surface of the drum 62.

[0013] On the other hand, as shown in Figure 3, in the developing unit 20 as a developing device, the toner T in the toner chamber 29 is agitated and conveyed by the rotation of the transport member (agitation member) 43 and sent to the toner supply chamber 28. The toner T is supported on the surface of the developing roller 32 by the magnetic force of the magnet roller 34 (fixed magnet). The developing roller 32 is a developer carrier that supports the developer (toner T) on its surface in order to develop the latent image formed on the drum 62. The toner T is triboelectrically charged by the developing blade 42, and the thickness of the layer on the circumferential surface of the developing roller 32 as a developer carrier is restricted.

[0014] The toner T is supplied to the drum 62 in accordance with the electrostatic latent image, and the latent image is developed. In this way, the latent image is made visible as a toner image. The drum 62 is an image carrier that carries the latent image and the image formed by the toner (toner image, developer image) on its surface. Also, as shown in Figure 2, in conjunction with the output timing of the laser beam L, the sheet material PA stored in the lower part of the main body A is fed out from the sheet tray 4 by the pickup roller 5a and the feed roller pair 5b. The sheet material PA is then transported via the transfer guide 6 to the transfer position between the drum 62 and the transfer roller 7. At this transfer position, the toner image is sequentially transferred from the drum 62 to the sheet material PA.

[0015] The sheet material PA onto which the toner image has been transferred is separated from the drum 62 and transported along the transport guide 8 to the fuser unit 9. The sheet material PA then passes through the nip section between the heating roller 9a and the pressure roller 9b that make up the fuser unit 9. Pressure and heat fixing is performed at this nip section, fixing the toner image to the sheet material PA. The sheet material PA that has undergone the toner image fixing process is transported to the discharge roller pair 10 and discharged into the discharge tray 11.

[0016] On the other hand, as shown in Figure 3, after transfer, the drum 62 has residual toner removed from its outer surface by the cleaning member 77 and is used again in the image forming process. The toner removed from the drum 62 is stored in the waste toner chamber 71b of the toner cleaning unit 60. The cleaning unit 60 is a photosensitive drum unit having a photosensitive drum 62. In the above, the charging roller 66, developing roller 32, transfer roller 7, and cleaning member 77 are process means that act on the drum 62.

[0017] [Overall cartridge configuration] The overall configuration of cartridge B will be explained using Figures 3, 4, and 5. Figure 3 is a cross-sectional view of cartridge B, and Figures 4 and 5 are perspective views illustrating the configuration of cartridge B. In this embodiment, the screws used to connect the components will be omitted from the explanation. Cartridge B has a cleaning unit (photoreceptor holding unit, drum holding unit, image carrier holding unit, first unit) 60 and a developing unit (developer carrier holding unit, second unit) 20.

[0018] As shown in Figure 3, the cleaning unit 60 includes a drum 62, a charging roller 66, a cleaning member 77, and a cleaning frame 71 that supports them. On the drive side, the drum 62 is rotatably supported by a drive-side drum flange 63 provided on the drive side, through a hole 73a of a drum bearing 73 (see Figure 4). In a broader sense, the drum bearing 73 and the cleaning frame 71 can be collectively referred to as the cleaning frame. On the non-drive side, as shown in Figure 5, the hole (not shown) of the non-drive side drum flange is rotatably supported by a drum shaft 78 that is press-fitted into a hole 71c provided in the cleaning frame 71.

[0019] Each drum flange is a bearinged part that is rotatably supported by a bearing. As shown in Figure 3, in the cleaning unit 60, the charging roller 66 and the cleaning member 77 are positioned in contact with the outer circumferential surface of the drum 62. The cleaning member 77 has a rubber blade 77a, which is a blade-shaped elastic member made of rubber as an elastic material, and a support member 77b that supports the rubber blade. The rubber blade 77a is in contact with the drum 62 in a counter-direction with respect to the rotation direction of the drum 62. That is, the tip of the rubber blade 77a is in contact with the drum 62 such that it faces upstream in the rotation direction r of the drum 62. The waste toner removed from the surface of the drum 62 by the cleaning member 77 is collected in the waste toner chamber 71b formed by the cleaning frame 71 and the cleaning member 77.

[0020] Furthermore, as shown in Figure 3, a squeegee sheet 65 is provided on the edge of the cleaning frame 71 so as to contact the drum 62, in order to prevent waste toner from leaking from the cleaning frame 71. The charging rollers 66 are rotatably attached to the cleaning unit 60 via charging roller bearings 67 at both ends in the longitudinal direction of the cleaning frame 71. The longitudinal direction of the cleaning frame 71 (the longitudinal direction of cartridge B) is approximately parallel to the direction in which the rotation axis of the drum 62 extends (axial direction). Therefore, unless otherwise specified, the axial direction of the drum 62 is intended when simply referred to as the longitudinal direction or simply the axial direction. The charging rollers 66 are pressed against the drum 62 by the charging roller bearings 67 being pressurized toward the drum 62 by a biasing member 68. The charging rollers 66 rotate in accordance with the rotation of the drum 62.

[0021] As shown in Figure 3, the developing unit 20 includes a developing roller 32, a developing container 23 that supports the developing roller 32, and a developing blade 42, etc. The developing roller 32 is rotatably attached to the developing container 23 by bearing members 26 (Figure 4) and 27 (Figure 5) provided at both ends. A magnetic roller 34 is also provided inside the developing roller 32. In the developing unit 20, a developing blade 42 is arranged to regulate the toner layer on the developing roller 32. As shown in Figures 4 and 5, spacing members 38 are attached to both ends of the developing roller 32, and the developing roller 32 is held with a small gap between it and the drum 62 by the contact between the spacing members 38 and the drum 62. Also, as shown in Figure 3, a blowout prevention sheet 33 is provided on the edge of the developing container 23 so as to contact the developing roller 32 in order to prevent toner from leaking from the developing unit 20. Furthermore, a transport member 43 is provided in the toner chamber 29 formed by the developing container 23 and the bottom member 22. The transport member 43 agitates the toner contained in the toner chamber 29 and transports the toner to the toner supply chamber 28.

[0022] As shown in Figures 4 and 5, cartridge B is composed of a cleaning unit 60 and a developing unit 20. The development unit 20 and the cleaning unit 60 are connected as follows. First, the center of the first development support boss 26a of the bearing member 26 is aligned with the first suspension hole 71i on the drive side of the cleaning frame 71, and the center of the second development support boss 27a of the bearing member 27 is aligned with the second suspension hole 71j on the non-drive side. Specifically, by moving the development unit 20 in the direction of arrow G, the first development support boss 26a and the second development support boss 27a are fitted into the first suspension hole 71i and the second suspension hole 71j. This connects the development unit 20 to the cleaning unit 60 in a movable manner. More specifically, the development unit 20 is connected to the cleaning unit 60 in a rotatable manner. That is, the developing roller 32 is connected to the drum 62 in a manner that allows it to move toward and away from it. After this, the drum bearing 73 is assembled to the cleaning unit 60 to form cartridge B.

[0023] In this embodiment, the non-drive biasing member 46L (Figure 5) and the drive biasing member 46R (Figure 4) are formed from compression springs. The biasing force of these springs causes the drive biasing member 46R and the non-drive biasing member 46L to bias the developing unit 20 toward the cleaning unit 60, thereby reliably pressing the developing roller 32 toward the drum 62. Furthermore, the developing roller 32 is provided with spacing-holding members 38 attached to both ends. That is, the drum 62 and the developing roller 32 come into contact with a predetermined contact pressure via the spacing-holding members 38, so that the developing roller 32 is held at a predetermined distance from the drum 62, and their relative positions are determined.

[0024] [Cartridge installed] The installation of cartridge B will be specifically explained using Figures 6(a), 6(b), 7(a), and 7(b). Figure 6(a) is a cross-sectional view of the drive-side guide section of image forming apparatus A for illustrating the installation of cartridge B, and Figure 6(b) is a cross-sectional view of the non-drive-side guide section of image forming apparatus A for illustrating the installation of cartridge B. Figure 7(a) is a cross-sectional view of the drive-side of image forming apparatus A for illustrating the positioning of cartridge B. Figure 7(b) is a cross-sectional view of the non-drive-side of image forming apparatus A for illustrating the positioning of cartridge B.

[0025] The installation of cartridge B will now be explained. As shown in Figures 6(a) and 6(b), the first drive side plate 15 has a guide rail 15g and a guide rail 15h, while the non-drive side plate 16 has a guide rail 16d and a guide rail 16e. The drum bearing 73 provided on the drive side of cartridge B has a rotation-preventing portion 73c. ​​The installation direction of cartridge B is substantially perpendicular to the axis of the drum 62 (Figure 3) (arrow C).

[0026] Furthermore, the cleaning frame 71 has a positioned portion 71d as a first positioning portion and a rotation-preventing portion 71f as a second positioning portion on the non-driven side in the longitudinal direction. When cartridge B is inserted into the cartridge insertion port 17 of the device body A, the driven side of cartridge B and the rotation-preventing portion 73c of cartridge B are guided by the guide rail 15h of the device body A. On the non-driven side of cartridge B, the positioned portion 71d and the rotation-preventing portion 71f of cartridge B are guided by the guide rails 16d and 16e of the device body A. As a result, cartridge B is installed in the device body A.

[0027] Next, the state in which the opening / closing door 13 is closed will be described. As shown in Figures 6(a), 6(b), 7(a), and 7(b), the first drive side plate 15 has a positioning upper part 15a, a positioning lower part 15b, and a rotation stopper part 15c for positioning, and the non-drive side plate 16 has a positioning part 16a and a rotation stopper upper part 16c. The drum bearing 73 has a positioned upper part (first positioned part, first projection, first overhang) 73d and a positioned lower part (second positioned part, second projection, second overhang) 73f.

[0028] Furthermore, the cartridge pressing members 1 and 2 are rotatably mounted at both axial ends of the opening / closing door 13. The cartridge pressing springs 19 and 21 are each mounted at both ends in the longitudinal direction of the front plate provided on the image forming apparatus A. The drum bearing 73 has a pressed portion 73e as a biasing force receiving portion, and the cleaning frame 71 has a pressed portion 71o on the non-driven side (see Figure 3). By closing the opening / closing door 13, the pressed portions 73e and 71o of the cartridge B are pressed by the cartridge pressing members 1 and 2, which are biased by the cartridge pressing springs 19 and 21 of the apparatus body A (see Figure 7).

[0029] As a result, on the drive side, the upper positioning portion 73d and lower positioning portion 73f of cartridge B, and the rotation stopper portion 73c are fixed to the upper positioning portion 15a, lower positioning portion 15b, and rotation stopper portion 15c of the device body A, respectively. This positions cartridge B and drum 62 on the drive side. On the non-drive side, the positioning portion 71d and rotation stopper portion 71f of cartridge B are fixed to the positioning portion 16a and rotation stopper portion 16c of the device body A, respectively. This positions cartridge B and drum 62 on the non-drive side.

[0030] Up to this point, the description has been presented as an example of a configuration for determining the position of cartridge B relative to the main body A of the device, but this is not intended to limit the means of positioning. It is also possible to configure the cartridge B to fix each positioning part by directly acting on the drive-side positioned part 73d, the rotation-stopping part 73f, and the non-drive-side positioned part 71d, the rotation-stopping part 71f.

[0031] Figures 8(a), 8(b), 8(c), and 8(d) will be used to explain the configuration in which cartridge B receives driving force from the main unit A. Figure 8(a) shows the configuration of the drive unit of the main unit A, and Figure 8(b) shows the configuration of the drive unit of cartridge B. Figure 8(c) shows the state before the main unit A and the drive unit of cartridge B engage. Figure 8(d) shows the state when the power to the main unit A is turned on and the main unit A and the drive unit of cartridge B engage.

[0032] As shown in Figure 8(a), the main body A of the device is provided with a drive transmission member 81 that receives driving force from a drive source (not shown) of the main body A and transmits that driving force to the cartridge B. Also, as shown in Figure 8(b), the cartridge B is provided with a drive-side drum flange 63 that engages with the drive transmission member 81 to receive driving force. When the opening / closing door 13 is closed and the power to the main body A of the device is turned on, the drive transmission member 81 moves in the direction of arrow E in Figure 8(c). Then, as shown in Figure 8(d), the drive transmission part 81b of the drive transmission member 81 and the drive-side drum flange 63 that engage with the drive-side drum flange 63, causing the drum 62 to rotate via the drive-side drum flange 63. In addition, a gear shape 81g is provided on the outer circumference of the drive transmission member 81. Furthermore, a developing roller gear 90 is coupled to the end of the developing roller 32 of the cartridge B. Furthermore, when the drive-passive portion 63b of the drive-side drum flange 63 shown in Figure 8(d) is engaged, the gear shape 81g provided on the drive transmission member 81 and the developing roller gear 90 are also arranged to mesh. That is, the drum 62 rotates via the drive-side drum flange by the drive transmission member 81, and at the same time, the developing roller 62 also rotates via the developing roller gear 90.

[0033] [Developer contact configuration] Figures 1, 9, and 11 will be used to explain the details of the development contact configuration of cartridge B, which is a characteristic of this embodiment. Figure 1 is an exploded perspective view of the development unit 20, showing the key parts of the development contact configuration. Figure 9 is a perspective view of cartridge B, Figure 11(a) is a side view of cartridge B to explain the development contact configuration, and Figure 11(b) is an enlarged cross-sectional view II of the area around the development contacts in Figure 11(a).

[0034] As shown in Figure 1, the developing unit 20 is provided with a developing container 23 as a first frame (first component) and a developing roller 32 as a process means. The developing container 23 has a density of 0.95 to 1.10 g / cm³ 3The material used is a resin material (first resin material) with a flame retardancy of HB according to the UL94 standard. Generally, resin materials have the property of burning when exposed to fire, but it is known that resins can be made flame retardant by adding additives to them. However, with the same type of resin material, the more additives are added to increase the flame retardancy, the greater the specific gravity of the resin, which increases the weight of the resin material required for the entire product, resulting in a problem of increased environmental burden. In this embodiment, the material used for the developing container 23 is a material that does not contain the above-mentioned additives and has a low density. The developing roller 32 has the function of carrying the developer when a predetermined bias is applied, and is supported in the developing container 23 as a rotatable rotating body via a bearing member 26 (see Figure 4) on the driving side and via a conductive bearing member 937 and a bearing member 27 on the non-driving side. Now, let's explain the flame retardancy performance. The UL94 standard was used to evaluate the flame retardancy performance in this embodiment. As an evaluation criterion for the flame retardancy performance of resins such as plastics, first of all, is whether or not they are self-extinguishing. UL94 combustion tests generally include horizontal combustion tests, which are performed on resin materials that do not have self-extinguishing properties, and vertical combustion tests, which are used on resin materials that do have self-extinguishing properties. HB material is an example of a resin material used in horizontal combustion tests. Examples of resin materials used in vertical combustion tests include 5VA, 5VB, V-0, V-1, and V-2 materials. As a guideline for grades in the UL94 standard, in the horizontal combustion test of HB material, it is required to demonstrate that it does not have self-extinguishing properties but is slow-burning, and for test specimens with a thickness of 3 mm or more, the burning rate must be 40 mm / min or less. In the vertical combustion test, V-0 material is required to burn for 10 seconds or less even when exposed to flame for 10 seconds twice, and V-1 and V-2 material is required to burn for 30 seconds or less even when exposed to flame for 10 seconds twice. Here, a shorter burning time indicates that it is less flammable. In other words, "high flame retardancy" in this embodiment includes not only the difference in flame retardancy grade, but also a shorter burning time when similar combustion tests are performed. In addition to the UL94 standard, the oxygen index according to the JIS standard may also be used. The oxygen index is an index that shows, as a percentage, the minimum oxygen concentration required for combustion to continue when a resin material is ignited.A higher oxygen index indicates higher flame retardancy. For example, HB material has an oxygen index of approximately 15-19, V-2 material is approximately 24-25, V-1 material is approximately 25-29, and V-0 material is 29 or higher.

[0035] As shown in Figure 1, Figure 11(a), and Figure 11(b), the conductive bearing member 937 is provided with a spring contact 1751, which is a power supply member of the image forming apparatus, and a conductive part 1701, which is an electrode member made of conductive resin, in order to apply a predetermined bias to the developing roller 32. The spring contact 1751 and the conductive part 1701 form an electrically conductive path between the apparatus body and the developing roller 32.

[0036] As shown in Figure 1, the conductive bearing member 937 is integrally molded with a conductive part 1701 and a non-conductive part 1702 as a second frame (second member). The non-conductive part 1702 has a density of 1.12 to 1.50 g / cm³. 3 The material (second resin material) has a flame retardancy of V-1 according to the UL94 standard, which is higher than that of the developing container 23. Furthermore, as shown in Figure 11, the conductive part 1701 has a contact part 1701a that is exposed to the outside in order to supply power by contacting the spring contact 1751, which is a power supply member of the image forming apparatus, and a conductive support part 1701b that serves as an axial support part that rotatably supports the developing roller 32.

[0037] Figure 13 is a diagram illustrating the details of the conductive bearing member 937, and Figures 13(b) and 13(c) are exploded views showing the conductive part 1701 and the non-conductive part 1702 offset in the longitudinal direction. Note that although Figures 13(b) and 13(c) show the conductive part 1701 and the non-conductive part 1702 arranged side by side in the longitudinal direction, they are integrated by fitting them together in the longitudinal direction. It is not a configuration in which they are formed in a single manner. In this embodiment, the conductive part 1701 and the non-conductive part 1702 are formed by two-color molding, and the conductive part 1701 has a portion that is molded around one side in the longitudinal direction relative to the non-conductive part 1702, and a portion that is molded around the other side. For example, the contact portion 1701a and the conductive support portion 1701b of the conductive part 1701 are portions that are molded on opposite sides in the longitudinal direction relative to the non-conductive part 1702. In other words, Figures 13(b) and 13(c) are diagrams that virtually show the conductive part 1701 and the non-conductive part 1702 shifted in the longitudinal direction in order to clearly illustrate the respective configurations (especially the components that are not visible from the outside when they are integrated). The state in which the conductive part 1701 and the non-conductive part 1702 are integrated is as shown in Figure 13(a).

[0038] As shown in Figure 13(c), the non-conductive portion 1702 has an electrode seating surface 1702c, which is a surface that faces the contact portion 1701a in the longitudinal direction and extends in a direction perpendicular to the longitudinal direction.

[0039] Here, the contact portion 1701a of the conductive portion 1701 is positioned in contact with the non-conductive portion 1702 closer to the developing container 23. For example, if a discharge occurs between the spring contact 1751, which is the power supply portion, and the contact portion 1701a due to an abnormality in the high-voltage power supply of the main body A, it could potentially become an electrical source of ignition. In contrast, in this configuration, the non-conductive portion 1702, which has high flame retardancy, is positioned in contact with the contact portion 1701a. When ignition at the contact portion 1701a attempts to spread to the non-conductive portion 1702, the non-conductive portion 1702 can prevent the fire from spreading into the resin by generating non-combustible gas from within its material and by carbonizing the resin surface, thereby promoting self-extinguishing. As a result, even if the contact portion 1701a of the conductive portion 1701 is located near the developing container 23, the non-conductive portion 1702 is located closer to the contact portion 1701a than to the developing container 23, thereby preventing the fire from spreading to the developing container 23. In this embodiment, "nearby" refers to the area that would be affected by ignition if a discharge occurs between the power supply portion and the contact portion due to an abnormality or the like, and becomes an electrical source of ignition.

[0040] In other words, in this embodiment, cartridge B uses HB material, a low-density resin material, for the developing container 23 to reduce the overall weight of the product, while using V-1 material, which has high flame retardancy, near the connection point between the device body A and cartridge B, which is an electrical conductivity path. In this way, cartridge B can be provided that achieves both overall safety and weight reduction.

[0041] Furthermore, the density is 1.12-1.50 g / cm³. 3 The bearing member 27, which serves as a third frame (third component) and is made of a material with a flame retardancy of V-1 according to the UL94 standard, holds the conductive bearing member 937 and is fastened to the developing container 23. Furthermore, as shown in Figure 11(b), the bearing member 27 is provided with a protrusion 27a adjacent to the conductive part 1701 and which is convex in the longitudinal direction W compared to the electrode seat surface 1702c (see Figure 13) of the non-conductive part 1702. In other words, the bearing member 27 is provided with a protrusion 27a formed to shield the electrode seat surface 1702c of the non-conductive part 1702 from the outside. For example, due to an abnormality in the high-voltage power supply of the main body A, a discharge may occur between the spring contact 1751, which is the power supply part, and the contact part 1701a of the conductive part 1701, causing an electrical ignition. In this case, even if the portion from the contact portion 1701a of the conductive portion 1701 to the electrode seating surface 1702c of the non-conductive portion 1702 ignites in the longitudinal direction W, the non-combustible gas generated from the non-conductive portion 1702 and the bearing member 27 can be contained by the protrusion 27a. This further promotes the self-extinguishing of the non-conductive portion 1702 and stops the spread of fire at the electrode seating surface 1702c. Thus, safety can be further improved.

[0042] Regarding the configuration of the protruding portion 27a, from the viewpoint of containing non-combustible gases and suppressing the spread of fire, it is preferable that it protrudes so as to completely surround the periphery (outer circumference) of the electrode seating surface 1702c, but various configurations can be adopted as long as a certain effect is obtained. The spread of fire is upward in the vertical direction. Because of its tendency to spread easily, by arranging the protrusion 27a so as to block the space between the electrode seat surface 1702c and the developing container 23, which is the first frame, at least vertically above the electrode seat surface 1702c, it can be expected that the fire will not spread. In other words, if the protrusion of the present invention is configured to include at least a portion arranged vertically above the contact portion, it can suppress the spread of fire in the event of ignition. Needless to say, the same can be said for the configurations of the other protrusions described below.

[0043] Figure 13 is a perspective view illustrating the detailed configuration of the conductive bearing member 937. Figure 13(a) shows the conductive bearing member 937 with the conductive part 1701 and the non-conductive part 1702 integrally molded. Figures 13(b) and 13(c) are diagrams in which the conductive part 1701 and the non-conductive part 1702 of the conductive bearing member 937 are virtually offset in the longitudinal direction as described above, for illustrative purposes.

[0044] As shown in Figure 13(b), the conductive bearing member 937 is composed of a conductive part 1701 and a non-conductive part 1702 made of different resin materials, and the conductive part 1701 and the non-conductive part 1702 are molded together. The conductive part 1701 has a conductive support part 1701b that supports the inner circumference of the developing roller 32, which is a rotating body. Furthermore, Figure 13(d) is a cross-sectional view of Figure 13(a), and the non-conductive part 1702 has an inner circumference support part 1702a and an outer circumference support part 1702b for supporting the conductive part 1701. These inner circumference support part 1702a and outer circumference support part 1702b support the cylindrical conductive support part 1701b of the conductive part 1701 by sandwiching it from both the inner and outer circumference sides. As a result, even if a gap occurs between the conductive part 1701 and the non-conductive part 1702 due to the difference in thermal expansion coefficients of their materials, the inclination of the conductive support part 1701b relative to the non-conductive part 1702 can be reduced, making it possible to rotate the developing roller 32 stably.

[0045] Figure 14 is an enlarged view illustrating the detailed configuration of the conductive part 1701. The conductive part 1701 has a connecting part 1701e for connecting the contact part 1701a and the conductive support part 1701b. As described above, the conductive part 1701 and the non-conductive part 1702 are molded by two-color molding, and the conductive part 1701 has a portion where the resin wraps around to one side in the longitudinal direction during molding, and a portion where the resin wraps around to the other side during molding, relative to the non-conductive part 1702. The connecting part 1701e is the part that connects the contact part 1701a, which is the portion where the resin wraps around to one side in the longitudinal direction during molding, and the conductive support part 1701b, which is the portion where the resin wraps around to the other side during molding, relative to the non-conductive part 1702. Furthermore, in the two-color molding of the conductive part 1701, the resin is injected into the cavity in the following order: from the gate portion 1701c, which serves as the injection port, to the contact portion 1701a, the connecting portion 1701e, and the conductive support portion 1701b. In this configuration, when viewed in a direction perpendicular to the plane including the contact portion 1701a, the shape of the conductive part 1701 is such that the gate portion 1701c and the connecting portion 1701e overlap (overlap and are included in) the contact portion 1701a. Moreover, when viewed in the same direction, the contact portion 1701a and the conductive support portion 1701b partially overlap each other. In other words, the resin injection path from the gate portion 1701c to the conductive support portion 1701b can be made shorter compared to, for example, when an injection path is formed that bypasses the outside of the non-conductive part 1702. This reduces the amount of resin material used to make up the conductive part 1701, thereby minimizing the spread of fire through the conductive resin in the event that the contact part 1701a ignites, and resulting in a contact configuration with even higher safety.

[0046] In this embodiment, the developing container 23, which serves as the first frame, is made of PS (polystyrene). The non-conductive part 1702, which serves as the second frame, and the bearing member 27, which serves as the third frame, are made of PC+ABS (a mixed resin of polycarbonate and acrylonitrile butadiene styrene), and the conductive part 1701, which serves as the resin electrode member, is made of conductive POM (polyacetal). These materials are not limited to those used in this embodiment.

[0047] [Static contact configuration] Figures 10, 12(a), and 12(b) will be used to explain the details of the electrostatic contact configuration, which is a characteristic of this embodiment. Figure 10 is an exploded perspective view showing key parts of the electrostatic contact configuration, Figure 12(a) is a side view for explaining the electrostatic contact configuration, and Figure 12(b) is an enlarged cross-sectional view of the electrostatic contact in Figure 12(a).

[0048] As shown in Figure 10, the cleaning unit 60 is provided with a cleaning frame 71 as a first frame. Inside the cleaning frame 71, as shown in Figure 3, a charging roller 66 is provided as a process means, and as shown in Figure 10, an electrode plate 82 is attached to the non-driven side of the cleaning frame 71 for electrically connecting the charging roller 66 to the main body of the device. The cleaning frame 71 has a density of 0.95 to 1.10 g / cm³ 3 The material used is of a certain degree and has a flame retardancy of HB according to the UL94 standard. The charging roller 66 is supported on the cleaning frame 71 as a rotatable rotating body via a charging roller bearing 67. The charging roller 66 rotates while being subjected to a predetermined bias, thereby uniformly charging the surface of the photosensitive drum 62. The cleaning unit 60 has an electrode plate 82, which is a metal electrode member, as an electrically conductive path from the image forming apparatus A to the charging roller 66 in order to apply a predetermined bias to the charging roller 66. The electrode plate 82 has a contact surface 82a that is exposed to the outside in order to receive power from a spring contact 1752, which is a power supply member disposed in the image forming apparatus.

[0049] Furthermore, the cleaning unit 60 has a density of 1.12 to 1.50 g / cm³. 3The second frame, a contact cover 83, is made of a material with a flame retardancy of V-1 according to the UL94 standard, which is higher than that of the cleaning frame 71. A part of the contact cover 83, which is a contact protection member, has a protrusion 83a that protrudes in the longitudinal direction W from the contact surface 82a, as shown in Figure 12(b). For example, if a foreign object such as dust, which is a flammable material, gets caught between the contact surface 82a of the spring contact 1752 and the electrode plate 82, and a bias is applied, the foreign object may ignite due to tracking. In such a case, the protrusion 83a, made of a highly flame-retardant material, functions as a fire spread prevention wall, thereby preventing the fire from spreading into the inside of the cartridge B, including the cleaning frame 71.

[0050] In other words, in this embodiment, cartridge B uses HB material, a low-density resin material, for the cleaning frame 71 to reduce the overall weight of the product. On the other hand, a protruding portion 83a of highly flame-retardant V-1 material is provided between the connection part between the device body A and cartridge B, which is an electrical conductivity path, and the cleaning frame 71. In this way, cartridge B can be provided that achieves both overall safety and weight reduction.

[0051] In this embodiment, the cleaning frame 71, which serves as the first frame, is made of PS; the contact cover 83, which serves as the second frame, is made of PC+ABS; and the electrode plate 82, which serves as the metal electrode member, is made of SUS. These materials are not limited to those used in this embodiment.

[0052] Furthermore, although this embodiment describes a configuration in which the developing unit 20 and the cleaning unit 60 are integrated to form the process cartridge B, the configuration corresponding to the cartridge of the present invention is not limited to the configuration shown in this embodiment. For example, in a device configuration in which the developing unit 20 and the cleaning unit 60 can be individually and independently attached to and detached from the device body, each unit may be considered to correspond to the cartridge of the present invention. The same applies to the embodiments described later.

[0053] [Static contact configuration] Furthermore, other embodiments of the electrostatic contact configuration described earlier will be explained. Figure 34(a), Figure Figures 34(b), 35, 36(a), and 36(b) will be used to describe in detail another embodiment of the electrostatic contact configuration. Figure 34(a) is a perspective view of the cleaning frame body alone, showing the key parts of the electrostatic contact configuration. Figure 34(b) is a perspective view showing the key parts of the electrostatic contact configuration with the contact cover molded in two colors onto the cleaning frame body. Figure 35 is an exploded perspective view showing the key parts of the electrostatic contact configuration. Figure 36(a) is a side view for explaining the electrostatic contact configuration. Figure 36(b) is an enlarged HH cross-sectional view of the electrostatic contact in Figure 36(a). This embodiment is a modified example in which the contact cover 83 as the second frame described in Figure 10 is molded integrally with the cleaning frame body 3071. Therefore, other configurations are the same and will not be described further.

[0054] As shown in Figure 35, the cleaning unit 3060 is provided with a cleaning frame 3071 as the first frame. Here, the cleaning frame 3071 is composed of a cleaning frame body portion 3071a and a cleaning frame contact cover portion 3071b, as shown in Figures 34(a) and 34(b). The cleaning frame contact cover portion 3071b is integrally molded with the cleaning frame body portion 3071a by two-color molding. The cleaning frame body portion 3071a has a density of 0.95 to 1.10 g / cm³. 3 The material used is of a certain degree and has a flame retardancy of HB according to the UL94 standard. In addition, the cleaning frame contact cover part 3071b has a density of 1.12 to 1.50 g / cm³. 3 It is made of a material that has a higher flame retardancy rating of V-1 according to the UL94 standard, which is higher than that of the cleaning frame 71. Furthermore, the cleaning frame contact cover portion 3071b is a contact protection member, and a part of it has a protruding portion 3071c that protrudes longitudinally WW from the contact surface 3082a, as shown in Figure 36(b). For example, if a foreign object such as dust, which is flammable, gets caught between the contact surface 3082a of the spring contact 3752 and the electrode plate 3082, and a bias is applied, the foreign object may ignite due to tracking. In such a case, the protruding portion 3071c, which is made of a highly flame-retardant material, functions as a fire-spread prevention wall, thereby preventing the fire from spreading into the cartridge interior, including the cleaning frame 3071.

[0055] In other words, as described above, in the cartridge of this embodiment, the cleaning frame 3071 can be made lighter by using HB material, a low-density resin material. On the other hand, a protruding portion 3071c made of highly flame-retardant V-1 material is provided between the connection part between the device body and the cartridge, which is an electrical conductivity path, and the cleaning frame 3071. In this way, a cartridge that achieves both overall safety and weight reduction can be provided.

[0056] In this embodiment, the cleaning frame portion 3071a of the first frame, the cleaning frame portion 3071a, is made of PS, the cleaning frame contact cover portion 3071b, which has a similar role to the second frame described above, is made of PC+ABS, and the electrode plate 3082, which is a metal electrode member, is made of SUS. These materials are not limited to those of this embodiment.

[0057] <Example 2> [Overall configuration of the image forming apparatus 2600] The overall configuration of the electrophotographic image forming apparatus 2600 (hereinafter referred to as the image forming apparatus 2600) according to Embodiment 2 of the present invention will be described using Figure 16. Figure 16 is a schematic diagram of the image forming apparatus 2600 according to this embodiment. In this embodiment, the process cartridge 2500 and the toner cartridge 2550 are detachably attached to the main body of the image forming apparatus 2600. In this embodiment, the configuration and operation of the first to fourth image forming units are substantially the same, except that the color of the image formed is different. Therefore, in the following, the subscripts Y to K will be omitted and a general explanation will be given unless a particular distinction is necessary.

[0058] The first to fourth process cartridges 2500 are arranged horizontally. Each process cartridge 2500 is connected to a cleaning unit 2501 and a developing unit 250 The cleaning unit 2501 is formed from 2. The cleaning unit 2501 has a photosensitive drum 2503 as an image carrier, a charging roller 2504 as a charging means for uniformly charging the surface of the photosensitive drum 2503, and a cleaning blade 2505 as a cleaning means. The developing unit 2502 has a developing roller 2506 and a developer T (hereinafter referred to as toner), and has a developing means for developing an electrostatic latent image on the photosensitive drum 2503. The cleaning unit 2501 and the developing unit 2502 are supported so as to be able to swing relative to each other. The first process cartridge 1Y contains yellow (Y) toner in the developing unit 2502. Similarly, the second process cartridge 2500M contains magenta (M) toner, the third process cartridge 2500C contains cyan (C) toner, and the fourth process cartridge 2500K contains black (K) toner.

[0059] The process cartridge 2500 is detachable from the image forming apparatus 2600 via mounting means such as mounting guides (not shown) and positioning members (not shown) provided on the image forming apparatus 2600. Below the process cartridge 2500, a scanner unit 2601 is positioned as an exposure means for forming an electrostatic latent image. Furthermore, a waste toner transport unit 2616 is positioned behind the process cartridge 2500 in the image forming apparatus (downstream in the direction of attachment / detachment of the process cartridge 2500).

[0060] The first to fourth toner cartridges 2550 are arranged horizontally below each process cartridge 2500 in an order corresponding to the toner colors contained in each process cartridge 2500. Specifically, the first toner cartridge 2550Y contains yellow (Y) toner. Similarly, the second toner cartridge 2550M contains magenta (M), the third toner cartridge 2550C contains cyan (C), and the fourth toner cartridge 2550K contains black (K) toner. Each toner cartridge 2550 then replenishes the toner in the process cartridge 2500 containing the toner of the same color.

[0061] The toner cartridge 2550 is replenished when a toner level detection unit (not shown) located on the main body of the image forming apparatus 2600 detects insufficient toner in the process cartridge 2500. The toner cartridge 2550 is detachable from the image forming apparatus 2600 via mounting means such as mounting guides (not shown) and positioning members (not shown) provided on the image forming apparatus 2600. A detailed description of the process cartridge 2500 will be provided later.

[0062] Below the toner cartridge 2550, the first to fourth toner transport devices 2602 are arranged corresponding to each toner cartridge 2550. Each toner transport device 2602 transports the toner received from each toner cartridge 2550 upward and supplies toner to each developing unit 2502. Above the process cartridge 2500, an intermediate transfer unit 2604 is provided as an intermediate transfer body. The intermediate transfer unit 2604 is arranged substantially horizontally with the primary transfer section S1 side facing downward. The intermediate transfer belt 2603 facing each photosensitive drum 2503 is a rotatable endless belt and is stretched over a plurality of tension rollers. On the inner surface of the intermediate transfer belt 2603, primary transfer rollers 2605 are arranged as primary transfer members, positioned to form the primary transfer section S1 with each photosensitive drum 2503 via the intermediate transfer belt 2603. Furthermore, the secondary transfer roller 2606, which is a secondary transfer member, contacts the intermediate transfer belt 2603 and forms the secondary transfer section S2 with the opposing roller via the intermediate transfer belt 2603. In addition, in the left-right direction (the direction in which the secondary transfer section S2 and the intermediate transfer belt are stretched), the intermediate transfer belt cleaning unit 2607 is positioned on the side opposite to the secondary transfer section S2.

[0063] A fixing unit 2608 is positioned above the intermediate transfer unit 2604. The fixing unit 2608 consists of a heating unit 2609 and a pressure roller 2610 that presses against the heating unit 2609. The top surface of the device body has an output tray 2611, and a waste toner collection container 2612 is positioned between the output tray 2611 and the intermediate transfer unit. Furthermore, a paper feed tray 2613 for accommodating the recording material 2700 is positioned at the bottom of the device body.

[0064] [Image Formation Process] The image forming operation in the image forming apparatus 2600 will be explained using Figures 16 and 17. Figure 17 is a schematic cross-sectional view of the process cartridge according to this embodiment.

[0065] During image formation, the photosensitive drum 2503 is driven to rotate at a predetermined speed in the direction of arrow a in Figure 17. The intermediate transfer belt 2603 is driven to rotate in the direction of arrow b in Figure 16 (forward of the rotation of the photosensitive drum 2503).

[0066] First, the surface of the photosensitive drum 2503 is uniformly charged by the charging roller 2504. Next, the surface of the photosensitive drum 2503 is scanned and exposed by laser light irradiated from the scanner unit 2601, forming an electrostatic latent image on the photosensitive drum 2503 based on image information. The electrostatic latent image formed on the photosensitive drum 2503 is developed as a toner image (developer image) by the developing unit 2502. At this time, the developing unit 2502 is pressurized by a developing pressure unit (not shown) provided in the main body of the image forming apparatus 2600. Then, the toner image formed on the photosensitive drum 2503 is primary transferred onto the intermediate transfer belt 2603 by the primary transfer roller 2605.

[0067] For example, when forming a full-color image, the above-described process is carried out sequentially in the first to fourth primary transfer sections, which are the image forming sections S1Y to S1K, so that toner images of each color are sequentially superimposed on the intermediate transfer belt 2603.

[0068] Meanwhile, the recording material 2700 contained in the paper feed tray 2613 is fed at a predetermined control timing and transported to the secondary transfer section S2 in synchronization with the movement of the intermediate transfer belt 2603. Then, the four-color toner image on the intermediate transfer belt 2603 is transferred collectively onto the recording material 2700 by the secondary transfer roller 2606, which is in contact with the intermediate transfer belt 2603 via the recording material 2700.

[0069] Subsequently, the recording material 2700 onto which the toner image has been transferred is transported to the fixing unit 2608. In the fixing unit 2608, the recording material 2700 is heated and pressurized, fixing the toner image onto the recording material 2700. After that, the fixed recording material 2700 is transported to the discharge tray 2611, completing the image formation operation. In addition, any primary transfer residue toner (waste toner) remaining on the photosensitive drum 2503 after the primary transfer process is removed by the cleaning blade 2505. Any secondary transfer residue toner (waste toner) remaining on the intermediate transfer belt 2603 after the secondary transfer process is removed by the intermediate transfer belt cleaning unit 2607. The waste toner removed by the cleaning blade 2505 and the intermediate transfer belt cleaning unit 2607 is transported by a waste toner transport unit 2616 provided in the main body of the device and accumulated in the waste toner collection container 2612. Furthermore, the image forming apparatus 2600 can also form monochrome or multicolor images using only one or some (but not all) of the desired image forming units.

[0070] [Processing cartridge] The overall configuration of the process cartridge 2500 installed in the image forming apparatus 2600 according to this embodiment will be explained using Figures 17 and 18. Figure 17 is a schematic cross-sectional view of the process cartridge 2500 according to this embodiment. Figure 18(a) is a view from the bottom side. Figure 18(b) is a perspective view of the process cartridge 2500.

[0071] The process cartridge 2500 is formed from a cleaning unit 2501 and a developing unit 2502. The cleaning unit 2501 and the developing unit 2502 are pivotably coupled around a rotating support pin 2507.

[0072] The cleaning unit 2501 has a cleaning frame 2508 that supports various components within the cleaning unit 2501. In addition to the photosensitive drum 2503, the charging roller 2504, and the cleaning blade 2505, the cleaning unit 2501 also has a waste toner screw 2509 that extends in a direction parallel to the rotation axis of the photosensitive drum 2503. Cleaning bearings 2511 that rotatably support the photosensitive drum 2503 are disposed at both longitudinal ends of the cleaning unit 2501 on the cleaning frame 2508. The cleaning bearings 2511 are equipped with a cleaning gear train for transmitting drive from the photosensitive drum 2503 to the waste toner screw 2509.

[0073] The charging roller 2504 is biased in the direction of arrow c by charging roller pressure springs 2512 positioned at both ends toward the photosensitive drum 2503. The charging roller 2504 is configured to follow the photosensitive drum 2503, and when the photosensitive drum 2503 is driven to rotate in the direction of arrow a during image formation, it rotates in the direction of arrow d (forward of the rotation of the photosensitive drum 2503).

[0074] The cleaning blade 2505 consists of an elastic member 2505a for removing residual toner (waste toner) remaining on the surface of the photosensitive drum 2503 after primary transfer, and a support member 2505b for supporting the elastic member 2505a. The waste toner removed from the surface of the photosensitive drum 2503 by the cleaning blade 2505 is contained in a waste toner storage chamber 2513 formed by the cleaning blade 2505 and the cleaning frame 2508. The waste toner contained in the waste toner storage chamber 2513 is transported toward the rear of the image forming apparatus 2600 (downstream in the direction of attachment / detachment of the process cartridge 2500) by a waste toner screw 2509 installed in the waste toner storage chamber 2513. The transported waste toner is discharged from the waste toner discharge section 2618 and handed over to the waste toner transport unit 2616 of the image forming apparatus 2600.

[0075] The developing unit 2502 has a developing frame 2614 that supports various components within the developing unit 2502. The developing frame 2614 is divided into a developing chamber 2514a, which houses the developing roller 2506 and the supply roller 2515, and a toner storage chamber 2514b, which houses the toner and houses the agitator 2516.

[0076] The developing chamber 2514a is equipped with a developing roller 2506, a supply roller 2515, and a developing blade 2517. The developing roller 2506 carries toner as a developer carrier and rotates in the direction of arrow e during image formation, contacting the photosensitive drum 2503 to transport toner to the photosensitive drum 2503. The developing roller 2506 is rotatably supported on the developing frame 2514 by developing bearing units 2518 at both ends in its longitudinal direction (direction of rotation axis). The supply roller 2515, as a developer supply member, is rotatably supported on the developing frame 2514 by developing bearing units 2518 while in contact with the developing roller 2506, and rotates in the direction of arrow f during image formation. Furthermore, a developing blade 2517, which serves as a layer thickness regulating member to regulate the thickness of the toner layer formed on the developing roller 2506, is positioned to abut the surface of the developing roller 2506.

[0077] The toner storage chamber 2514b is equipped with a stirring member 2516 for agitating the stored toner T and for transporting the toner to the supply roller 2515 via the developing chamber communication port 2514c. The stirring member 2516 has a rotating shaft 2516a parallel to the rotation axis direction of the developing roller 2506, and a stirring sheet 2516b which is a flexible sheet and serves as a conveying member. One end of the stirring sheet 2516b is attached to the rotating shaft 2516a, and the other end of the stirring sheet 2516b is a free end. When the rotating shaft 2516a rotates, the stirring sheet 2516b rotates in the direction of arrow g, and the toner is stirred by the stirring sheet 2516b.

[0078] The developing unit 2502 has a developing chamber communication port 2514c that connects the developing chamber 2514a and the toner storage chamber 2514b. In this embodiment, when the developing unit 2502 is in its normal operating position (operating position), the developing chamber 2514a is located above the toner storage chamber 2514b. The toner in the toner storage chamber 2514b, which has been pumped up by the stirring member 2516, is supplied to the developing chamber 2514a through the developing chamber communication port 2514c.

[0079] Furthermore, the developing unit 2502 is provided with a receiving port 2519 at one end on the downstream side in the loading / unloading direction. Above the toner receiving port 2519 are a receiving port sealing member 2520 and a toner receiving port shutter 2521 that is movable in the front-rear direction. The toner receiving port 2519 is closed by the toner receiving port shutter 2521 when the process cartridge 2500 is not installed in the image forming apparatus 2600. The toner receiving port shutter 2521 is configured to open when biased by the image forming apparatus 2600 in conjunction with the loading / unloading operation of the process cartridge 2500. A receiving transport path 2522 is provided in communication with the toner receiving port 2519, and a receiving transport screw 2523 is arranged inside it. Furthermore, a storage chamber communication port 2524 for supplying toner to the toner storage chamber 2514b is provided near the longitudinal center of the developing unit 2518, and the receiving transport path 2522 and the toner storage chamber 2514b are connected. The receiving and transporting screw 2523 extends parallel to the rotation axis direction of the developing roller 2506 and the supply roller 2515, and transports the toner received from the toner receiving port 2519 to the toner storage chamber 2514b via the storage chamber communication port 2524.

[0080] [Developer contact configuration] Figures 15, 19, and 20 will be used to explain the details of the developer contact configuration, which is a characteristic of this embodiment. Figure 15 is an exploded perspective view of the developer unit 2502, showing the key parts of the developer contact configuration. Figure 19 is a perspective view of the developer unit 2502, Figure 20(a) is a side view for explaining the developer contact configuration, and Figure 20(b) is an enlarged cross-sectional view of the BB of the developer contact in Figure 20(a).

[0081] As shown in FIG. 15, the developing unit 2502 is provided with a developing frame body 2514 as a first frame body and a developing roller 2506 as a process means. The developing frame body 2514 is made of a material with a density of about 0.95 to 1.10 g / cm 3 and having a flame retardancy of HB in the UL94 standard. Generally, resin materials have the property of burning when in contact with fire, but it is known that resins can be made flame retardant by adding additives to the resin materials. And in the same type of resin material, the specific gravity of the resin increases as additives are added to enhance the flame retardant effect. Therefore, there is a possibility that the weight of the resin material required for the entire product increases and the environmental load becomes large. In this embodiment, as the material used for the developing frame body 2514, a material with a small density and without the use of the above additives is used. The developing roller 2506 has a function of carrying the developer by being applied with a predetermined bias, and is supported by the developing frame body 2514 as a rotatable rotating body via the developing bearing unit 2518.

[0082] As shown in FIG. 15 and FIGS. 20(a) and 20(b), the developing bearing unit 2518 is provided with a conductive part 2530 which is an electrode member formed of a conductive resin in order to apply a predetermined bias to the developing roller 2506. Through the conductive part 2530, an electrically conductive path is formed from the developing spring contact 2620 which is a power supply member of the image forming apparatus to the developing roller 2506. A path is formed.

[0083] As shown in FIG. 15, the developing bearing unit 2518 is integrally formed by means such as two-color molding with the conductive part 2530 and a non-conductive part 2531 as a second frame body. The non-conductive part 2531 has a density of about 1.12 to 1.50 g / cm 3 and is made of a material having a flame retardancy of V-0 in the UL94 standard with a higher flame retardant performance than the developing frame body 2514. Also, as shown in FIG. 15, the conductive part 2530 has a contact part 2530a exposed to the outside for power supply by contacting the developing spring contact 2620 (FIG. 20(b)) which is a power supply member of the image forming apparatus, and a conductive support part 2530b that rotatably supports the developing roller 2506.

[0084] As shown in Figure 20(b), in this configuration, the seating surface for forming the conductive portion 2530 is formed by the non-conductive portion 2531, which is the second frame. When the seating surface formed by this non-conductive portion 2531 is called 2531a, the non-conductive portion 2531 has a protruding portion 2531b that is adjacent to the conductive portion 2530 and protrudes from the seating surface 2531a in a direction perpendicular to the seating surface 2531a. The conductive portion 2530 is formed by two-color molding so that all surfaces except the surface that contacts the developing spring contact 2620 are surrounded by the non-conductive portion 2531.

[0085] At the contact surface between the developing spring contact 2620 and the conductive part 2530 of the image forming apparatus body, for example, if a discharge occurs between the contact surface 2530a of the developing spring contact 2620, which is the power supply part, and the conductive part 2530 due to a high-voltage power supply malfunction, it could potentially become an electrical ignition source. In contrast, in this configuration, a highly flame-retardant non-conductive part 2531 is formed to surround the conductive part 2530. With this configuration, when ignition at the contact surface 2530a attempts to spread to the non-conductive part 2531, a non-combustible gas generated from within the material of the non-conductive part 2531 will self-extinguish, preventing the fire from spreading to the developing frame 2514.

[0086] In other words, in this embodiment as well, the developing frame 2514 uses HB material, a low-density resin material, to reduce the overall weight of the product. On the other hand, V-0 material, which has high flame retardancy, is used near the connection point between the device body and the process cartridge, which is an electrical conductivity path. In this way, a process cartridge that achieves both overall safety and weight reduction can be provided.

[0087] [Static contact configuration] Figures 17, 21, 22(a), and 22(b) will be used to explain the details of the electrostatic contact configuration, which is a characteristic of this embodiment. Figure 21 is an exploded perspective view showing key parts of the electrostatic contact configuration, Figure 22(a) is a side view for explaining the electrostatic contact configuration, and Figure 22(b) is an enlarged EE cross-sectional view of the electrostatic contact in Figure 22(a).

[0088] As shown in Figure 17, the cleaning unit 2501 is provided with a cleaning frame 2508 as a first frame and a charging roller 2504 as a process means (charging member). The cleaning frame 2508 has a density of 0.95 to 1.10 g / cm³ 3 The material used is of a certain degree and has a flame retardancy of HB according to the UL94 standard. The charging roller 2504 is supported on the cleaning frame 2508 as a rotatable rotating body via the charging roller bearing 2525. The charging roller bearing 2525 consists of a charging roller bearing member 2526 made of conductive resin and a charging roller spring member 2512 made of a metal compression spring. The charging roller 2504 uniformly charges the surface of the photosensitive drum 2503 by rotating while being subjected to a predetermined bias. The cleaning unit 2501 has an electrode plate 2528, which is a metal electrode member as shown in Figure 21, as an electrically conductive path from the image forming apparatus 2600 to the charging roller 2504 in order to apply a predetermined bias to the charging roller 2504. As shown in Figure 22(b), the electrode plate 2528 has an externally exposed contact surface 2528a for power supply from a spring contact 2619, which is a power supply member disposed in the image forming apparatus. To possess.

[0089] Furthermore, the cleaning unit 2501 has a contact cover 2529 as a second frame. The contact cover 2529 has a density of 1.12 to 1.50 g / cm³ 3 The material is of a higher flame retardancy than the cleaning frame 2508, and is made of a material with a flame retardancy of V-0 according to the UL94 standard. A part of the contact cover 2529 has a protrusion 2529a that protrudes in the longitudinal direction W from the contact surface 2528a, as shown in Figure 22(b). For example, ignition due to tracking may occur when foreign matter, such as flammable dust, gets caught between the contact surface 2528a of the spring contact 2619 and the electrode plate 2528. In such cases, the protrusion 2529a, made of a highly flame-retardant material, functions as a fire spread prevention barrier. This prevents the fire from spreading into the process cartridge 2500, including the cleaning frame 2508.

[0090] Specifically, the cleaning frame 2508 is made of HB material, a low-density resin material, to reduce the overall weight of the product. At the same time, a protruding portion 2529a made of highly flame-retardant V-0 material is placed between the device body 2600, which is an electrical conductivity path, and the cleaning frame 2508. In this way, a cartridge that achieves both overall safety and weight reduction can be provided.

[0091] <Example 3> Hereinafter, Embodiment 3 of the present invention will be described with reference to the figures. In Embodiment 3, an image forming apparatus is provided as an example in which four process cartridges can be attached and detached. However, the number of process cartridges to be installed in the image forming apparatus is not limited to this. It can be set as appropriate as needed. Furthermore, in the embodiments described below, a laser beam printer is provided as an example of an image forming apparatus.

[0092] [Outline configuration of an image forming apparatus] Figure 23 is a schematic cross-sectional view of the image forming apparatus M. Figure 24 is a cross-sectional view of the process cartridge 2800. This image forming apparatus M is a four-color full-color laser printer using an electrophotographic process, and it forms color images on a recording medium (recording material) S. The image forming apparatus M uses a process cartridge system, and the process cartridge 2800 is detachably mounted on the image forming apparatus body 2870 to form color images on the recording medium S.

[0093] Here, with respect to the image forming apparatus M, the side with the front door 2711 is referred to as the front, and the side opposite the front is referred to as the rear. Also, when viewing the image forming apparatus M from the front, the right side is referred to as the drive side, and the left side as the non-drive side. Furthermore, when viewing the image forming apparatus M from the front, the upper side is referred to as the top surface, and the lower side is referred to as the bottom surface. Figure 23 is a cross-sectional view of the image forming apparatus M as seen from the non-drive side, with the front of the image forming apparatus M being at the front of the page, the right side of the page being the front, and the back of the page being the drive side.

[0094] Furthermore, the drive side of the process cartridge 2800 is the side on which the drum coupling member (photoreceptor coupling member), described later, is located, when viewed in the axial direction of the photosensitive drum. Also, the drive side of the process cartridge 2800 is the side on which the developing coupling member, described later, is located, when viewed in the axial direction of the developing roller (developing member).

[0095] The main body 2870 of the image forming apparatus has the first to fourth process cartridges 2800 (2800Y, 2800M, 2800C, 2800K) arranged in a roughly horizontal direction. Each of the first to fourth process cartridges 2800 (2800Y, 2800M, 2800C, 2800K) has a similar electrophotographic process mechanism, but the developer (hereinafter referred to as toner) is different in color. Rotational driving force is transmitted to the Y, 2800M, 2800C, and 2800K process cartridges from the drive output section of the image forming apparatus main unit 2870 (details will be described later). In addition, bias voltages (charging bias, development bias, etc.) are supplied to each of the first to fourth process cartridges 2800 (2800Y, 2800M, 2800C, and 2800K) from the image forming apparatus main unit 2870 (not shown).

[0096] As shown in Figure 24, each of the first to fourth process cartridges 2800 in this embodiment has a photosensitive drum 2804 and a drum unit 2808 equipped with a charging means as a process means that acts on the photosensitive drum 2804. Here, the drum unit 2808 may also have a cleaning means in addition to the charging means as a process means. Furthermore, each of the first to fourth process cartridges 2800 (2800Y, 2800M, 2800C, 2800K) has a developing unit 2809 equipped with a developing means for developing the electrostatic latent image on the photosensitive drum 2804.

[0097] The drum unit 2808 and the developer unit 2809 are coupled together. The more specific configuration of the process cartridge 2800 will be described later. The first process cartridge 2800Y contains yellow (Y) toner in the developer frame 2825 and forms a yellow toner image on the surface of the photosensitive drum 2804. The second process cartridge 2800M contains magenta (M) toner in the developer frame 2825 and forms a magenta toner image on the surface of the photosensitive drum 2804. The third process cartridge 2800C contains cyan (C) toner in the developer frame 2825 and forms a cyan toner image on the surface of the photosensitive drum 2804. The fourth process cartridge 2800K contains black (K) toner in the developer frame 2825 and forms a black toner image on the surface of the photosensitive drum 2804.

[0098] Above the first to fourth process cartridges 2800 (2800Y, 2800M, 2800C, 2800K), a laser scanner unit 2714 is provided as an exposure means. This laser scanner unit 2714 outputs laser light L corresponding to image information. The laser light L then passes through the exposure window 2810 of the process cartridge 2800 and scans and exposes the surface of the photosensitive drum 2804. Below the first to fourth process cartridges 2800 (2800Y, 2800M, 2800C, 2800K), an intermediate transfer unit 2712 is provided as a transfer member. This intermediate transfer unit 2712 has a drive roller 2712e, a turn roller 2712c, and a tension roller 2712b, and a flexible transfer belt 2712a is stretched across it. The photosensitive drum 2804 of each of the first to fourth process cartridges 2800 (2800Y, 2800M, 2800C, 2800K) has its lower surface in contact with the upper surface of the transfer belt 2712a. This contact area is the primary transfer area. Inside the transfer belt 2712a, a primary transfer roller 2712d is provided, facing the photosensitive drum 2804.

[0099] The secondary transfer roller 2706 is in contact with the drive roller 2712e via the transfer belt 2712a. The contact area between the transfer belt 2712a and the secondary transfer roller 2706 is the secondary transfer area. Below the intermediate transfer unit 2712, a feeding unit 2704 is provided. This feeding unit 2704 has a paper feed tray 2704a that holds and accommodates the recording medium S, and a paper feed roller 2704b.

[0100] In Figure 23, a fuser unit 2707 and a paper output unit 2708 are located in the upper left of the main body 2870 of the image forming apparatus. The top surface of the main body 2870 of the image forming apparatus is the paper output tray 2713. The toner image is fixed onto the recording medium S by the fixing means provided in the fuser unit 2707 and then discharged to the paper output tray 2713.

[0101] [Image Formation Process] The operation for forming a full-color image is as follows: The photosensitive drums 2804 of each of the first to fourth process cartridges 2800 (2800Y, 2800M, 2800C, 2800K) are rotated at a predetermined speed (direction of arrow A in Figure 24).

[0102] The transfer belt 2712a is also driven to rotate in the forward direction (direction of arrow C in Figure 23) of the rotation of the photosensitive drum 2804 at a speed corresponding to the speed of the photosensitive drum 2804. The laser scanner unit 2714 is also driven. Synchronized with the driving of the laser scanner unit 2714, the charging roller 2805 in each process cartridge uniformly charges the surface of the photosensitive drum 2804 to a predetermined polarity and potential. The laser scanner unit 2714 scans and exposes the surface of each photosensitive drum 2804 with laser light L according to the image signal of each color. As a result, an electrostatic latent image corresponding to the image signal of the corresponding color is formed on the surface of each photosensitive drum 2804. The formed electrostatic latent image is developed by the developing roller 2806, which is driven to rotate at a predetermined speed.

[0103] Through the electrophotographic image formation process described above, a yellow toner image corresponding to the yellow component of the full-color image is formed on the photosensitive drum 2804 of the first process cartridge 2800Y. This toner image is then primary transferred onto the transfer belt 2712a. Similarly, a magenta toner image corresponding to the magenta component of the full-color image is formed on the photosensitive drum 2804 of the second process cartridge 2800M. This toner image is then primary transferred by being superimposed on the yellow toner image already transferred onto the transfer belt 2712a. Similarly, a cyan toner image corresponding to the cyan component of the full-color image is formed on the photosensitive drum 2804 of the third process cartridge 2800C. This toner image is then primary transferred by being superimposed on the yellow and magenta toner images already transferred onto the transfer belt 2712a. Similarly, a black toner image corresponding to the black component of the full-color image is formed on the photosensitive drum 2804 of the fourth process cartridge 2800K. Then, the toner image is superimposed on the yellow, magenta, and cyan toner images that have already been transferred onto the transfer belt 2712a, and the primary transfer is performed.

[0104] In this way, a full-color unfixed toner image of four colors—yellow, magenta, cyan, and black—is formed on the transfer belt 2712a. Meanwhile, the recording media S are separated and fed one by one at predetermined control timings. The recording media S is then introduced into the secondary transfer section, which is the contact point between the secondary transfer roller 2706 and the transfer belt 2712a, at predetermined control timings. As a result, during the process of transporting the recording media S to the secondary transfer section, the four-color superimposed toner image on the transfer belt 2712a is sequentially and simultaneously transferred to the surface of the recording media S. The configuration of the image forming apparatus body will be described in more detail below.

[0105] [Process Cartridge Removal Configuration Overview] Figures 25 to 27 will be used to further describe the cartridge tray (hereinafter referred to as the tray) 2871 that supports the process cartridge 2800. Figure 25 is a cross-sectional view of the image forming apparatus M with the front door 2711 open and the tray 2871 located inside the image forming apparatus body 2870. Figure 26 is a cross-sectional view of the image forming apparatus M with the front door 2711 open and the tray 2871 located outside the image forming apparatus body 2870, with the process cartridge 2800 stored inside the tray. Figure 27 is a cross-sectional view of the image forming apparatus M with the front door 2711 open and the tray 2871 located outside the image forming apparatus body 2870, with the process cartridge 2800 removed from the tray 2871.

[0106] As shown in Figures 25 and 26, the tray 2871 is movable in the direction of arrow X1 (pushing direction) and arrow X2 (pulling direction), which are substantially horizontal relative to the image forming apparatus body 2870. The tray 2871 is provided to be pull-out and push-in, and is configured to be movable in a substantially horizontal direction when the image forming apparatus body 2870 is installed on a horizontal plane. Here, the state in which the tray 2871 is located outside the image forming apparatus body 2870 (the state in Figure 26) is referred to as the outside position. Also, the state in which the tray 2871 is located inside the image forming apparatus body 2870 with the front door 2711 open, and the photosensitive drum 2804 and transfer belt 2712a are separated (the state in Figure 25) is referred to as the inside position.

[0107] Furthermore, the tray 2871 has a mounting section 2871a on its outer side, into which the process cartridge 2800 can be detachably mounted, as shown in Figure 27. The process cartridge 2800, while positioned in the mounting section 2871a, moves inward into the image forming apparatus body 2870 as the tray 2871 moves. At this time, a gap is left between the transfer belt 2712a and the photosensitive drum 2804 as it moves. In this embodiment, when the front door 2711 is closed, the intermediate transfer unit 2712 rises in the direction of arrow Z1 by a link mechanism (not shown) and moves to the position for image formation (the position where the photosensitive drum 2804 and the intermediate transfer belt 2712a are in contact). When the front door 2711 is opened, the intermediate transfer unit 2712 descends in the direction of arrow Z2, and the photosensitive drum 2804 and the intermediate transfer belt 2712a are separated. Therefore, the tray 2871 can move the process cartridges 2800 inside the image forming apparatus body 2870 without the photosensitive drum 2804 coming into contact with the transfer belt 2712a. As described above, the tray 2871 can move multiple process cartridges 2800 together to a position where image formation can be performed inside the image forming apparatus body 2870, and can also pull them out together to the outside of the image forming apparatus body 2870.

[0108] [Overall configuration of the process cartridge] The configuration of the process cartridge 2800 will be explained using Figures 24, 28, 29, 30, and 31. Figure 28 is an exploded perspective view of the drum unit 2808. Figure 29 is an exploded perspective view of the developing unit 2809. Figure 30 is an exploded perspective view of the process cartridge 2800 from the drive side, which is one end of the photosensitive drum 2804 in the axial direction. Figure 31 is an assembled perspective view of the process cartridge 2800 from the drive side.

[0109] In this embodiment, the first to fourth process cartridges 2800 (2800Y, 2800M, 2800C, 2800K) have similar electrophotographic process mechanisms, but differ in the color of the toner they contain and the amount of toner they contain.

[0110] The process cartridge 2800 comprises a photosensitive drum 2804 (2804Y, 2804M, 2804C, 2804K) and process means that act on the photosensitive drum 2804. Here, the process means include a charging roller 2805 as a charging means for charging the photosensitive drum 2804, and a developing roller 2806 as a developing means for developing the latent image formed on the photosensitive drum 2804. The process cartridge 2800 is further divided into a drum unit 2808 (2808Y, 2808M, 2808C, 2808K) and a developing unit 2809 (2809Y, 2809M, 2809C, 2809K). In the following description, the longitudinal directions (Y1, Y2 directions) of the drum unit 2808 and the developing unit 2809 are directions approximately parallel to the rotation axis ax of the photosensitive drum 2810.

[0111] [Drum Unit Configuration] As shown in Figures 28 and 30, the drum unit 2808 consists of a photosensitive drum 2804, a charging roller 2805, and a drum frame 2815 which is the first frame. The charging roller 2805 is rotatably supported by a drive-side charging roller bearing 2820a and a non-drive-side charging roller bearing 2820b, and is biased against the photosensitive drum 2804 by pressure springs 2821a and 2821b. The photosensitive drum 2804 is supported by drive-side cartridge cover members 2816 provided at both longitudinal ends of the process cartridge 2800, and a second frame which is the non-drive-side cartridge... It is rotatably supported by the drive cover member 2817. Furthermore, the non-drive side cartridge cover member 2817 is provided with an electrode member 2860 that receives power from the image forming apparatus main body 2870. Further details will be described later.

[0112] As shown in Figures 30 and 31, a coupling member 2843 for transmitting driving force to the photosensitive drum 2804 is provided on one longitudinal end of the photosensitive drum 2804. The coupling member 2843 engages with the main body-side drum drive coupling 2880 (see Figure 26), which serves as the drum drive output section of the image forming apparatus body 2870. The driving force of the drive motor (not shown) of the image forming apparatus body 2870 is transmitted to the photosensitive drum 2804 via the coupling member 2843, causing the photosensitive drum 2804 to rotate in the direction of arrow A (Figure 24). The photosensitive drum 2804 also has a drum flange 2842 on the other longitudinal end. The charging roller 2805 is supported on the drum frame 2815 so as to contact the photosensitive drum 2804 and be driven to rotate.

[0113] [Developing Unit Configuration] As shown in Figures 24 and 29, the developing unit 2809 consists of a developing roller 2806, a toner transport roller 2807, a developing blade 2830, a developing frame 2825, and the like. The fourth frame (fourth member), the developing frame 2825, is composed of a lower frame 2825a and a lid member 2825b. Here, the UL94 flame retardancy of the lower frame 2825a and the lid member 2825b is HB. The lower frame 2825a and the lid member 2825b are joined together by ultrasonic welding or the like. The developing frame 2825 has a toner storage section 2829 for storing toner supplied to the developing roller 2806. Furthermore, the developing frame 2825 rotatably supports the developing roller 2806 and the toner transport roller 2807 via the drive-side bearing 2826 and the non-drive-side bearing 2827, and holds the developing blade 2830 which regulates the thickness of the toner layer on the circumferential surface of the developing roller 2806.

[0114] The developing blade 2830 consists of an elastic member 2830b, which is a sheet of metal with a thickness of approximately 0.1 mm, attached to a support member 2830a, which is a metal material having an L-shaped cross-section, by welding or other means. The developing blade 2830 is attached to the developing frame 2825 at two points, one end and the other end in the longitudinal direction, with fixing screws 2830c. The developing roller 2806 consists of a metal core 2806c and a rubber part 2806d.

[0115] The developing roller 2806 is rotatably supported by drive-side bearings 2826 and non-drive-side bearings 2827, which are mounted on both longitudinal ends of the developing frame 2825. Also, as shown in Figure 30, a developing drive input gear 2832 for transmitting driving force to the developing unit 2809 is provided on one longitudinal end of the developing unit 2809. The developing drive input gear 2832 is provided with a developing input coupling section 2832a that receives drive from the main body side developing drive coupling 2885 (see Figure 26) of the image forming apparatus body 2870. The driving force of the drive motor (not shown) of the image forming apparatus body 2870 is input to the developing unit 2809 via the developing input coupling section 2832a, the developing drive input gear 2832, etc.

[0116] The driving force input to the developing unit 2809 is transmitted to the developing roller gear 2831, which allows the developing roller 2806 to rotate in the direction of arrow D in Figure 24. As shown in Figure 29, a developing cover member 2828 that supports and covers the developing drive input gear 2832 is provided at one longitudinal end of the developing unit 2809. The outer diameter of the developing roller 2806 is set to be smaller than the outer diameter of the photosensitive drum 2804. In this embodiment, the outer diameter of the photosensitive drum 2804 is set in the range of Φ18 to Φ22, and the outer diameter of the developing roller 2806 is set in the range of Φ8 to Φ14. Setting the outer diameters to these ranges allows for efficient arrangement.

[0117] [Assembly of the drum unit and developing unit] The assembly of the drum unit 2808 and the developing unit 2809 will be explained using Figure 30. The drum unit 2808 and the developing unit 2809 are connected by the drive-side cartridge cover member 2816 and the non-moving-side cartridge cover member 2817, which are provided at both ends in the longitudinal direction of the process cartridge 2800.

[0118] The drive-side cartridge cover member 2816, located at one longitudinal end of the process cartridge 2800, is provided with a developing unit support hole 2816a for pivotably supporting the developing unit 2809. Similarly, the non-drive-side cartridge cover member 2817, located at the other longitudinal end of the process cartridge 2800, is provided with a developing unit support hole 2817a for pivotably supporting the developing unit 2809. Furthermore, the drive-side cartridge cover member 2816 and the non-drive-side cartridge cover member 2817 are provided with drum support holes 2816b and 2817b, respectively, for rotatably supporting the photosensitive drum 2804.

[0119] Here, at one end, the outer diameter of the cylindrical portion 2828b of the developing cover member 2828 is fitted into the developing unit support hole 2816a of the driving-side cartridge cover member 2816. At the other end, the outer diameter of the cylindrical portion (not shown) of the non-driving-side bearing 2827 is fitted into the developing unit support hole 2817a of the non-driving-side cartridge cover member 2817. Furthermore, both longitudinal ends of the photosensitive drum 2804 are fitted into the drum support hole 2816b of the driving-side cartridge cover member 2816 and the drum support hole 2817b of the non-driving-side cartridge cover member 2817. The driving-side cartridge cover member 2816 and the non-driving-side cartridge cover member 2817 are then fixed to the drum unit 2808 with screws, adhesive, etc. (not shown). As a result, the developing unit 2809 is rotatably supported relative to the drum unit 2808 (photosensitive drum 2804) by the drive-side cartridge cover member 2816 and the non-moving-side cartridge cover member 2817. This allows the developing roller 2806 to be positioned to act on the photosensitive drum 2804 during image formation.

[0120] Figure 31 shows the drum unit 2808 and the developing unit 2809 assembled through the above process and integrally formed as a process cartridge 2800. The axis connecting the center of the developing unit support hole 2816a of the drive-side cartridge cover member 2816 and the center of the developing unit support hole 2817a of the non-moving-side cartridge cover member 2817 is referred to as the pivot axis K. Here, the cylindrical portion 2828b of the developing cover member 2828 on one end is coaxial with the developing input coupling 2774. In other words, the developing unit 2809 is configured to receive driving force from the image forming apparatus body 2870 at this pivot axis K. Furthermore, the developing unit 2809 is supported so as to be rotatable around the pivot axis K.

[0121] [Configuration of the power supply section of the process cartridge] The configuration of the power supply unit in this embodiment will be explained using Figure 32. Figure 32(a) is a perspective view showing the area around the connection portion with the non-drive side cartridge cover member 2817 in the drum unit 2808, and is a perspective view showing only the electrode member 2860 in disassembled form. Figure 32(b) is a cross-sectional view of the electrode member 2860. Figure 32(c) is a cross-sectional view of FF in Figure 32(a) with the electrode member 2860 attached. Figure 32(d) is a cross-sectional view of JJ in Figure 32(a) with the electrode member 2860 attached.

[0122] The first frame, the drum frame 2815, has a conductive resin 2818 integrally attached to it by two-color molding. The conductive resin 2818 has a surface 2818a that contacts the electrode member 2860 and a surface 2818b that serves as the seating surface for the pressure spring 2821b. Here, similar to Example 1, the first frame, the drum frame, has a density of 0.95 to 1.10 g / cm³. 3 The flame retardancy level is HB according to the UL94 standard.

[0123] The electrode member 2860 is made of SUS material with a thickness of approximately 0.2 mm. The electrode member 2860 has an embossed contact portion 2860c that contacts the surface 2818a of the conductive resin 2818, and a contact surface 2860d that contacts and receives power from the electrode spring 2893 (Figures 33(b) and 33(c)) which receives power from the image forming apparatus body 2870. The second frame, the non-moving cartridge cover member 2817, supports the electrode member 2860.

[0124] Here, the second frame, the non-moving cartridge cover member 2817, has a density of 1.12 to 1.50 g / cm³. 3 The flame retardancy of the material is V-1 according to the UL94 standard. The electrode member 2860 is fixed in place by the positioning portion 2860a fitting with the boss 2817c of the non-drive side cartridge cover member 2817, and the cut-out portion 2860b biting into the surface 2817d of the boss 2817c (Figure 32(c)).

[0125] Furthermore, as shown in Figure 32(b), the contact portion 2860c side of the electrode member 2860 is bent by approximately 3° in the direction of the conductive resin 2818 with respect to the mounting surface 2860e with respect to the non-drive side cartridge cover member 2817. This is to prevent the contact portion 2860c of the electrode member 2860 from separating from the surface 2818a of the conductive resin 2818 when the electrode member 2860 is assembled to the non-drive side cartridge cover member 2817. Because the contact portion 2860c side is bent in a direction that penetrates the surface 2818a of the conductive resin 2818, when the electrode member 2860 is assembled to the non-drive side cartridge cover member 2817, the contact portion 2860c contacts the surface 2818a of the conductive resin 2818 with a constant pressure. Therefore, even if there are dimensional variations in the conductive resin 2818, the non-drive side cartridge cover member 2817, and the electrode member 2860, the surface 2818a of the conductive resin 2818 and the contact portion 2860c of the electrode member 2860 are always in contact. This prevents poor conductivity due to poor contact between the electrode member 2860 and the conductive resin 2818, as well as ignition due to tracking.

[0126] The voltage supplied from the contact spring 2893 to the electrode member 2860 is then supplied to the charging roller 2805 via the conductive resin 2818 molded in two colors on the drum frame 2815, the pressure spring 2821b, and the non-driven charging roller bearing 2820b.

[0127] Furthermore, although the conductive resin 2818 is molded in two colors, it may also be fixed as a separate part to the drum frame 2815, which serves as the first frame. Also, although the electrode member 2860 is fixed by cutting and bending 2860b, it may also be fixed with screws or rivets. In addition, although the electrode member 2860 is configured with the contact portion 2860c bent relative to the mounting surface 2860e, this is not limited to this configuration. The thickness of the electrode member 2860 may be increased to form a deep embossed shape so that it is always in contact with the surface 2818a of the conductive resin 2818.

[0128] [Configuration of the image forming apparatus main unit and the power supply unit for the process cartridge] The configuration of the power supply unit, including the main body 2870 of the image forming apparatus, will be explained using Figures 25 and 33. Figure 33(a) is a perspective view of the process cartridge with the memory element communication unit 2890 and the contact spring holding member 2892 lowered. Figure 33(b) is an enlarged view of the power supply unit in the VV cross-section in Figure 33(a). Figure 33(c) is an enlarged view of the power supply unit in the NN cross-section in Figure 33(a).

[0129] The main body 2870 of the image forming apparatus is provided with a contact spring holding member 2892, which holds a contact spring 2893 for supplying power to the process cartridge 2800. The contact spring holding member 2892 is fixed to a memory element communication unit 2890 that communicates with memory elements (not shown) provided in the process cartridge 2800.

[0130] The front door 2711 shown in Figure 25 is linked with a link mechanism (not shown), and the contact spring The configuration allows for contact and non-contact between 2893 and the electrode member 2860. Closing the front door 2711 causes the memory element communication unit 2890 and the contact spring retaining member 2892 to descend in the direction of arrow Z2 (Figure 33(b)). Opening the front door 2711 causes the memory element communication unit 2890 and the contact spring retaining member 2892 to rise in the direction of arrow Z1. In other words, closing the front door 2711 causes the contact spring 2893 and the electrode member 2860 to come into contact, and opening the front door 2711 causes the contact spring 2893 and the electrode member 2860 to separate. The UL94 flame retardancy of the contact spring retaining member 2892 is V-1.

[0131] As shown in Figure 33(b), protrusions 2817f are provided on both sides of the electrode member 2860 (in the directions of arrows X1 and X2), projecting from the non-drive side cartridge cover member 2817 in the direction of arrow Z1. The height H1 of the protrusions 2817f is set to be higher in the Z1 direction than the contact surface 2860d between the contact spring 2893 and the electrode member 2860. Furthermore, it is desirable to position the contact spring 2893 and the electrode member 2860 close together so that the range of fire spread Q in the event of ignition due to tracking from between the contact spring 2893 and the electrode member 2860 is narrowed. Here, the range of fire spread Q in the X1 and X2 directions is the range indicated by Q in Figure 33(b), since the fire spreads upward and the non-drive side cartridge cover member 2817 is made of V-1 material and is self-extinguishing, so it does not burn.

[0132] Furthermore, as shown in Figure 33(c), a projection 2817g is provided on the longitudinal arrow Y1 side of the electrode member 2860, integrally connecting the Y1-direction end of the projection 2817f of the non-drive side cartridge cover member 2817. The height H2 of the projection 2817g is set to be higher in the Z1 direction than the contact surface 2860d of the contact spring 2893 and the electrode member 2860. Moreover, it is desirable to position it near the contact spring 2893 and the electrode member 2860 so that the fire spread range R is narrowed, similar to the X1 and X2 directions. Here, the fire spread range R in the Y1 and Y2 directions is the range indicated by R in Figure 33(c), because, similar to the X1 and X2 directions, the fire spreads upward, and the non-drive side cartridge cover member 2817 is made of V-1 material and is self-extinguishing, so it does not burn.

[0133] Furthermore, longitudinal projections 2892a and 2892b are provided from the contact spring holding member 2892. The projections 2892a and 2892b are set to block the fire spread area R.

[0134] Next, we will explain what happens when ignition occurs due to tracking between the contact spring 2893 and the electrode member 2860. If ignition occurs between the contact spring 2893 and the electrode member 2860, the fire will attempt to spread to the fire spread areas Q and R. However, the contact spring holding member 2892, located above the ignition point (in the Z1 direction), and the non-drive side cartridge cover member 2817, located along the longitudinal (Y1, Y2 directions) and front-to-back (X1, X2 directions) of the ignition point, have a flame retardancy of V-1 and are self-extinguishing, so the fire will not spread. On the other hand, if the protrusions 2817f and 2817g are not provided, the fire will spread to the fire spread areas Q' and R'. Therefore, since there is nothing to suppress the spread of fire, there is a possibility that the fire will spread to the developing frame 2825, which uses HB material with low flame retardancy. In contrast, in this embodiment, protrusions 2817f and 2817g of the non-drive side cartridge cover member 2817 and protrusions 2892a and 2892b of the contact spring holding member 2892, which have a flame retardancy of V-1, are provided in the flame spread area, so the flame will not spread to parts with lower flame retardancy.

[0135] As described above, protrusions 2817f and 2817g of the non-drive side cartridge cover member 2817 are provided around the electrode member 2860, and a contact spring retaining member 2892 having protrusions 2892a and 2892b is positioned above the fire spread area. Furthermore, the non-drive side cartridge cover member 2817 and the contact spring retaining member 2892 are made of a material with UL94 standard flame retardancy V-1. As a result, even if ignition due to tracking occurs, the fire will not spread to parts with low flame retardancy, thus providing a process cartridge and image forming apparatus that ensure safety.

[0136] In this embodiment, the electrode member 2860 is surrounded by a protrusion from the non-drive side cartridge cover member 2817, but this is not limited to this configuration. A protrusion may be provided extending in the Z2 direction from the contact spring retaining member 2892 to surround the electrode member 2860. In addition, in this embodiment, the non-drive side cartridge cover member 2817 and the contact spring retaining member 2892 are flame retardant to UL94 standard V-1, but flame retardancy of V-1 or higher is also acceptable.

[0137] The process cartridge configurations and drum cartridge configurations of Examples 1 to 3 described above can also be expected to have the same effects of weight reduction and fire spread prevention even when they are not detachable from the main body of the image forming apparatus but are fixed to the image forming apparatus and integrated into the system. Therefore, the process cartridge configurations and drum cartridge configurations of Examples 1 to 3 can also be applied to configurations that are fixed to the image forming apparatus and not detachable. In this configuration, the use of HB material, a low-density resin material, makes it possible to reduce the weight of the entire image forming apparatus, thus achieving both safety and weight reduction of the image forming apparatus. As a result, the impact value of the image forming apparatus body during logistics can be reduced, allowing for smaller packaging materials for the image forming apparatus and improving logistics efficiency. [Explanation of Symbols]

[0138] 20...Developing unit, 23...Developing container, 27...Bearing member, 32...Developing roller, 937...Conductive bearing member, 1701...Conductive part, 1701a...Contact part, 1701b...Conductive support part, 1702...Non-conductive part

Claims

1. A cartridge for use in an image forming apparatus, a process means used to form an image; a first member made of a first resin material; a second member made of a second resin material having higher flame retardancy than the first resin material; an electrode member having a contact portion to which power is supplied from the main body of the image forming apparatus, and electrically connecting the main body of the apparatus and the processing means; In a cartridge having a density of the second resin material in the second member is greater than a density of the first resin material in the first member; The cartridge, wherein the contact portion is disposed near the first member and the second member, and is disposed closer to the second member than to the first member.

2. A cartridge for use in an image forming apparatus, a process means used to form an image; a first member made of a first resin material; a second member made of a second resin material having higher flame retardancy than the first resin material; an electrode member having a contact portion to which power is supplied from the main body of the image forming apparatus, and electrically connecting the main body of the apparatus and the processing means; In a cartridge having a density of the second resin material in the second member is greater than a density of the first resin material in the first member; The cartridge is characterized in that the contact portion is disposed on the second member.

3. The second member is an electrode seat surface on which the electrode member is disposed; a protrusion protruding from the electrode seat surface in a direction perpendicular to the electrode seat surface; 3. The cartridge according to claim 1, further comprising:

4. a third member integrally assembled with the first member and made of a second resin material having higher flame retardancy than the first resin material; the second member has an electrode seat surface on which the electrode member is disposed, 3. The cartridge according to claim 1, wherein the third member has a protruding portion that protrudes beyond the electrode seat surface in a direction perpendicular to the electrode seat surface.

5. 5. The cartridge according to claim 3, wherein the protrusion is provided so as to block a gap between the electrode seat surface and the first member.

6. 6. The cartridge according to claim 3, wherein the protrusion protrudes so as to surround the outer periphery of the electrode seat surface.

7. a fourth member made of the first resin material; 7. The cartridge according to claim 3, wherein the protrusion is provided so as to block a gap between the electrode seat surface and the fourth member.

8. 8. The cartridge according to claim 1, wherein the first resin material and the second resin material have different flame retardancy grades according to UL94.

9. the first resin material is a resin material having a flame retardancy of HB according to UL94, 9. The cartridge according to claim 8, wherein the second resin material is a resin material having a flame retardancy of V-1 according to UL94.

10. 10. A cartridge according to claim 1, wherein the electrode member is made of a resin material having electrical conductivity.

11. the process means is a rotating body, the second member and the electrode member are integrally formed with each other and are a bearing member that rotatably supports the process means; The electrode member is a shaft support for supplying power to the process means; a connection portion that connects the contact portion and the shaft support portion; a gate portion for injecting resin during molding; and The cartridge according to claim 10, wherein when viewed in a direction perpendicular to the surface of the contact portion, the connection portion and the gate portion are included in the contact portion, and the shaft support portion at least partially overlaps with the contact portion.

12. The shaft support portion is formed in a cylindrical shape, 12. The cartridge according to claim 11, wherein the second member has an inner peripheral support portion that supports an inner periphery of the shaft support portion, and an outer peripheral support portion that supports an outer periphery of the shaft support portion.

13. 9. The cartridge according to claim 1, wherein the electrode member is made of a metal material.

14. 14. The cartridge according to claim 1, wherein the process means is any one of an image carrier, a developer carrier, and a charging member.

15. 15. The cartridge according to claim 1, wherein the cartridge is detachable from the main body of the apparatus.

16. 16. The cartridge according to claim 1, wherein the first member supports the process means.

17. 17. A cartridge according to claim 1, wherein the second member is integrally assembled with the first member.

18. 18. A cartridge according to claim 1, wherein the electrode member is assembled so as to be in contact with at least the second member.

19. An image forming apparatus for forming an image on a recording material, A device body, An image forming apparatus comprising: a cartridge according to any one of claims 1 to 18, which is detachably mountable to the main body of the apparatus.

20. A cartridge for use in an image forming apparatus, a process means used to form an image; a first member made of a first resin material; a second member made of a second resin material having higher flame retardancy than the first resin material; The image forming apparatus has a contact portion to which power is supplied from the main body of the image forming apparatus, and the main body of the image forming apparatus and the processor an electrode member electrically connecting the sensor means to the electrode member; In a cartridge having a density of the second resin material in the second member is greater than a density of the first resin material in the first member; A cartridge characterized in that the second member is positioned so that, in the event that the contact portion becomes an ignition source due to power being supplied to the electrode member from the device main body, the first member will not ignite but will be self-extinguished by the second member.

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