Process cartridge

Abstract

To provide a process cartridge capable of stably pressing a developing roller against a photosensitive drum.SOLUTION: A process cartridge 1 is provided, having a development unit 6 comprising a coupling member 48 for receiving driving power from a device main body, a power transmission member 46 for transmitting the driving power transmitted from the coupling member 48 to a developing roller 11, and a support member 49 capable of rotatably supporting the coupling member 48 and moving the coupling member with respect to a development frame 16 in a direction crossing a rotation axis of the developing roller 11, where the development frame 16 and the power transmission member 46 can be integrally moved with respect to a drum frame 33 of a drum unit 4 in a direction crossing the rotation axis, and the process cartridge has a spring member 37 engaged with both the support member 49 and the drum frame 33 such that a spring force acts in a direction to bring a positioning target part 49c of the support member 49 into contact with a positioning part 33a of the drum frame 33.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a process cartridge that is detachably mountable to a main body of an electrophotographic image forming apparatus. [Background technology]

[0002] In electrophotographic image forming apparatuses such as copiers and printers, a process cartridge is known that integrates a photosensitive member and a process means that acts on the photosensitive member, and is detachably mounted on the main body of the electrophotographic image forming apparatus. In such process cartridge-type apparatus configurations, a widely proposed configuration is one in which the developing device is configured to be pivotable around the photosensitive drum, and a pressing means presses the developing roller against the photosensitive drum, thereby bringing the developing roller into contact with the photosensitive drum. Patent Document 1 also proposes a configuration in which an Oldham coupling is used at the end of the developing roller, and a pressing member is employed to hold the Oldham coupling in a predetermined position when the process cartridge is inserted into the main body of the image forming apparatus. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-137790 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention is a further development of the above-mentioned prior art, and its object is to provide a process cartridge that can stably press the developing roller against the photosensitive drum. [Means for solving the problem]

[0005] In order to achieve the above object, the process cartridge of the present invention comprises: A process cartridge detachably mountable to a main body of an image forming apparatus, a drum unit having a photosensitive drum and a drum frame that rotatably supports the photosensitive drum; A developing roller; a developing frame that rotatably supports the developing roller; a drive transmission unit including a rotatable coupling member provided at an end of the developing frame body in the direction of the rotation axis of the developing roller, for receiving a drive force for rotating the developing roller from the apparatus main body, and a rotatable drive transmission member for transmitting the drive force transmitted from the coupling member to the developing roller, wherein the coupling member and the drive transmission member are configured to be relatively movable in a direction intersecting the rotation axis; a support member that rotatably supports the coupling member and is provided so as to be movable relative to the developing frame and the drive transmission member in a direction intersecting the rotation axis; a developing unit including the developing frame and the drive transmission member configured to be movable integrally with the drum frame in a direction intersecting the rotation axis between a contact position where the developing roller contacts the photosensitive drum and a separation position where the developing roller is separated from the photosensitive drum; Equipped with the support member has a positioned portion, the drum frame has a positioning portion that abuts against the positioned portion of the support member in a direction intersecting the rotation axis to determine the position of the support member relative to the drum frame, A direction in which the positioned portion of the support member and the positioning portion of the drum frame come into contact with each other. The drum frame has a biasing member that engages with both the support member and the drum frame so that a biasing force acts on the support member and the drum frame. [Effects of the Invention]

[0006] According to the present invention, it is possible to propose a process cartridge that can stably press the developing roller against the photosensitive drum. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a side view of a process cartridge according to an embodiment of the present invention; [Figure 2] Schematic cross-sectional view of an image forming apparatus according to an embodiment of the present invention. [Figure 3] 1 is a cross-sectional view of a process cartridge according to an embodiment of the present invention; [Figure 4] 1 is a perspective view of a process cartridge according to an embodiment of the present invention; [Figure 5] 1 is a perspective view of a process cartridge according to an embodiment of the present invention; [Figure 6] 1 is a perspective view of a process cartridge according to an embodiment of the present invention; [Figure 7] Cross section of a toner cartridge [Figure 8] 1 is a diagram illustrating the configuration of a coupling unit according to an embodiment of the present invention; [Figure 9] FIG. 1 is a perspective view showing a side structure of a drive side of a process cartridge according to an embodiment of the present invention; [Figure 10] 1 is a side view of a process cartridge on a driving side according to an embodiment of the present invention; [Figure 11] Schematic diagram of the drive mechanism between the apparatus main body and the process cartridge [Figure 12] Schematic diagram of the drive mechanism between the apparatus main body and the process cartridge [Figure 13] Schematic diagram of the drive mechanism between the apparatus main body and the process cartridge DETAILED DESCRIPTION OF THE INVENTION

[0008] The following examples will exemplarily illustrate embodiments of the present disclosure. However, the configurations disclosed in the following examples, such as the functions, materials, shapes, and relative positions of components, are examples of embodiments related to the claims, and are not intended to limit the scope of the claims to the configurations disclosed in these examples. Furthermore, the problems solved by the configurations disclosed in the following examples or the actions or effects obtained from the disclosed configurations are not intended to limit the scope of the claims.

[0009] Example 1 An electrophotographic image forming apparatus according to a first embodiment of the present disclosure will be described below with reference to the drawings. Here, an electrophotographic image forming apparatus (hereinafter referred to as an image forming apparatus) forms an image on a recording material using an electrophotographic image forming method. Examples of image forming apparatuses include copiers, facsimile machines, printers (laser beam printers, LED printers, etc.), and multifunction printers (combined machines) of these. Examples of recording materials include sheet-like recording media such as recording paper and plastic sheets. The image forming apparatus according to this embodiment employs a so-called cartridge system. A cartridge is a unit that is detachable from the image forming apparatus and includes a photosensitive member and process means (e.g., a charging member, a developing member, a cleaning member, etc.) that act on the photosensitive member. In the following embodiment, a laser beam printer to which four process cartridges (cartridges) can be detachably attached is exemplified as the image forming apparatus. The number of process cartridges to be attached to the image forming apparatus is not limited to this number and may be set appropriately as needed.

[0010] <Overall Configuration of Image Forming Apparatus 100> The overall configuration of an electrophotographic image forming apparatus M (hereinafter referred to as image forming apparatus M) according to an embodiment of the present invention will be described with reference to Figures 2 and 3. Figure 2 is a schematic cross-sectional view of the image forming apparatus M (apparatus main body 100, process cartridge 1, toner cartridge 13) according to this embodiment. Figure 3 is a schematic cross-sectional view of the process cartridge 1.

[0011] The image forming apparatus M according to this embodiment is a four-color full-color laser printer that uses an electrophotographic process, and forms a color image on a recording material S. The image forming apparatus M is of a process cartridge type, and a process cartridge 1 is removably attached to an image forming apparatus main body (apparatus main body) 100 to form a color image on a recording material S. In this embodiment, the process cartridge 1 and the toner cartridge 13 are detachably attached to the apparatus main body 100 of the image forming apparatus M.

[0012] Here, with regard to the image forming apparatus M, the right side of the page in FIG. 2 is the front side (front surface), and the side on the left side of the page opposite the front side is the back side (rear surface). Also, when looking at the image forming apparatus M from the front, the right side is called the drive side, and the left side is called the non-drive side. Also, when looking at the image forming apparatus M from the front, the upper side is called the top side, and the lower side is called the bottom side. FIG. 2 is a cross-sectional view of the image forming apparatus M as seen from the non-drive side, with the front side of the page being the non-drive side of the image forming apparatus M and the back side of the page being the drive side of the image forming apparatus M.

[0013] The drive side of the process cartridge 1 is the side on which a drum coupling member (photosensitive member coupling member) described later is arranged with respect to the axial direction of the photosensitive drum (the axial direction of the rotational axis of the photosensitive drum). The drive side of the process cartridge 1 is the side on which a developer coupling member (photosensitive member coupling member) described later is arranged with respect to the axial direction of the developing roller (developing member) (the axial direction of the rotational axis of the developing roller). The axial direction of the photosensitive drum and the axial direction of the developing roller are parallel, and the longitudinal direction of the process cartridge 1 (photosensitive drum, developing roller) is also parallel to these.

[0014] In this embodiment, a process cartridge is provided for each of the four toner colors (yellow (Y), magenta (M), cyan (C), and black (K)) for forming a color image, and these constitute first to fourth image forming units, respectively. The configurations and operations of the first to fourth image forming units are substantially the same except that the colors of the images they form are different. Therefore, in the following, unless a particular distinction is required, the subscripts Y to K will be omitted and the units will be generally described.

[0015] The first to fourth process cartridges 1 are arranged horizontally. Each process cartridge 1 includes a drum unit (also referred to as a cleaning unit) 4 and a developing unit 6. The drum unit 4 includes a photosensitive drum 7 as an image carrier, a charging roller 8 as charging means for uniformly charging the surface of the photosensitive drum 7, and a cleaning blade 10 as cleaning means. The developing unit 6 includes a developing roller 11 and developing means for developing an electrostatic latent image on the photosensitive drum 7, containing developer T (hereinafter referred to as toner). The drum unit 4 and developing unit 6 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 6. Similarly, the second process cartridge 1M contains magenta (M) toner, the third process cartridge 1C contains cyan (C) toner, and the fourth process cartridge 1K contains black (K) toner.

[0016] The process cartridge 1 is detachably mounted to the apparatus main body 100 via mounting means such as a mounting guide (not shown) and a positioning member (not shown) provided in the apparatus main body 100. A scanner unit 12 for forming an electrostatic latent image is disposed below the process cartridge 1. A waste toner transport unit 23 is disposed in the apparatus main body 100 behind the process cartridge 1 (downstream in the mounting / removal direction of the process cartridge 1).

[0017] The first to fourth toner cartridges 13 are arranged in a horizontal line below the process cartridge 1 in an order corresponding to the color of the toner contained in each process cartridge 1. The first toner cartridge 13Y contains yellow (Y) toner. Similarly, the second toner cartridge 13M contains magenta (M) toner, and the third toner cartridge 13Y contains magenta (M) toner. The fourth toner cartridge 13C stores cyan (C) toner, and the fourth toner cartridge 13K stores black (K) toner. Each toner cartridge 13 supplies toner to the process cartridge 1 that stores toner of the same color.

[0018] The toner cartridge 13 is replenished when a remaining amount detection unit (not shown) provided in the main body of the image forming apparatus 100 detects that the amount of toner remaining in the process cartridge 1 is low. The toner cartridge 13 is detachable from the main body 100 of the apparatus via mounting means such as a mounting guide (not shown) and a positioning member (not shown) provided in the main body 100 of the apparatus. The process cartridge 1 and the toner cartridge 13 will be described in detail later.

[0019] Below the toner cartridges 13, first to fourth toner transport devices 14 are arranged corresponding to the respective toner cartridges 13. Each toner transport device 14 transports the toner received from the corresponding toner cartridge 13 upward and supplies the toner to each development unit 6.

[0020] An intermediate transfer unit 19 serving as an intermediate transfer body is provided above the process cartridge 1. The intermediate transfer unit 19 is disposed substantially horizontally with the primary transfer portion S1 facing downward. An intermediate transfer belt 18 facing each photosensitive drum 7 is a rotatable, endless belt that is stretched over multiple stretching rollers. Primary transfer rollers 20 serving as primary transfer members are disposed on the inner surface of the intermediate transfer belt 18 at positions that form the primary transfer portion S1 with each photosensitive drum 7 via the intermediate transfer belt 18. A secondary transfer roller 21 serving as a secondary transfer member contacts the intermediate transfer belt 18 and forms a secondary transfer portion S2 with an opposing roller via the intermediate transfer belt 18. Furthermore, an intermediate transfer belt drum unit 22 is disposed on the opposite side of the secondary transfer portion S2 in the left-right direction (the direction in which the secondary transfer portion S2 and the intermediate transfer belt are stretched).

[0021] A fixing unit 25 is disposed above the intermediate transfer unit 19. The fixing unit is composed of a heating unit 26 and a pressure roller 27 that is in pressure contact with the heating unit. A discharge tray 32 is disposed on the top surface of the apparatus main body 100, and a waste toner collection container 24 is disposed between the discharge tray 32 and the intermediate transfer unit 19. A paper feed tray 2 for storing recording materials 3 is disposed at the bottom of the apparatus main body 100.

[0022] <Image formation process> The image forming operation of the image forming apparatus M of this embodiment will be described with reference to FIGS.

[0023] During image formation, the photosensitive drum 7 is rotated at a predetermined speed in the direction of arrow A in Fig. 3. The intermediate transfer belt 18 is rotated in the direction of arrow B (the same direction as the rotation of the photosensitive drum 7).

[0024] First, the surface of the photosensitive drum 7 is uniformly charged by the charging roller 8. Next, the surface of the photosensitive drum 7 is scanned and exposed to laser light emitted from the scanner unit 12, thereby forming an electrostatic latent image on the photosensitive drum 7 based on image information. The electrostatic latent image formed on the photosensitive drum 7 is developed into a toner image by the developing unit 6. At this time, the developing unit 6 is pressurized by a developing pressure unit (not shown) provided in the main body of the apparatus 100, and is maintained in a predetermined contact state with the drum unit 4 for developing the toner image. Then, the toner image formed on the photosensitive drum 7 is primarily transferred onto the intermediate transfer belt 18 by the primary transfer roller 20.

[0025] For example, when a full-color image is formed, the above-described process is sequentially performed in the image forming units S1Y to S1K, which are the first to fourth primary transfer units, so that toner images of each color are sequentially superimposed on the intermediate transfer belt 18.

[0026] Meanwhile, the recording material 3 stored in the paper feed tray 2 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 18. Then, the four-color toner image on the intermediate transfer belt 18 is secondarily transferred onto the recording material 3 all at once by a secondary transfer roller 21 that is in contact with the intermediate transfer belt 18 via the recording material 3.

[0027] Thereafter, the recording material 3 onto which the toner image has been transferred is conveyed to the fixing unit 25. The recording material 3 is heated and pressurized in the fixing unit 25, thereby fixing the toner image to the recording material 3. Thereafter, the fixed recording material 3 is conveyed to the discharge tray 32, thereby completing the image forming operation.

[0028] Here, primary transfer residual toner (waste toner) remaining on the photosensitive drum 7 after the primary transfer process is removed by a cleaning blade 10. Secondary transfer residual toner (waste toner) remaining on the intermediate transfer belt 18 after the secondary transfer process is removed by an intermediate transfer belt drum unit 22. The waste toner removed by the cleaning blade 10 and intermediate transfer belt drum unit 22 is transported by a waste toner transport unit 23 provided in the device main body 100 and accumulated in a waste toner collection container 24.

[0029] The image forming apparatus M of this embodiment is also capable of forming a monochromatic or multicolor image by using only a desired single or some (but not all) of the image forming units.

[0030] <Process cartridge> The overall configuration of the process cartridge 1 to be mounted in the apparatus main body 100 of the image forming apparatus M according to this embodiment will be described with reference to Figures 3 to 6. Figure 4 is a perspective view of the process cartridge 1 as viewed obliquely from above the rear side (the upstream side in the process cartridge mounting / removal direction, the non-drive side). Figure 5 is a perspective view of the process cartridge 1 as viewed obliquely from above the front side (the downstream side in the process cartridge mounting / removal direction, the drive side). Figure 6 is a perspective view of the process cartridge 1 as viewed obliquely from above the front side, showing the state before the development unit 6 is coupled with the drum unit 4.

[0031] The process cartridge 1 includes a drum unit 4 and a developing unit 6.

[0032] The drum unit 4 has a drum unit frame 5 that supports various components within the drum unit 4. In addition to the photosensitive drum 7, charging roller 8, and cleaning blade 10, the drum unit 4 also contains a waste toner screw 15 that extends in a direction parallel to the rotational axis of the photosensitive drum 7. The drum unit frame 5 rotatably supports the photosensitive drum 7, and bearing members 33 equipped with gear trains for transmitting driving force from the photosensitive drum 7 to the waste toner screw 15 are disposed on both longitudinal ends of the drum unit 4.

[0033] The charging roller 8 provided in the drum unit 4 is biased in the direction of arrow C toward the photosensitive drum 7 by a charging roller pressure spring 80. The charging roller 8 is provided to follow the rotation of the photosensitive drum 7, and when the photosensitive drum 7 is rotationally driven in the direction of arrow A during image formation, the charging roller 8 rotates in the direction of arrow D (the forward direction of the rotation of the photosensitive drum 7).

[0034] The cleaning blade 10 provided in the drum unit 4 is composed of an elastic member 10a for removing residual toner (waste toner) remaining on the surface of the photosensitive drum 7 after the primary transfer, and a support member 10b for supporting the elastic member 10a. The waste toner removed from the surface of the photosensitive drum 7 by the cleaning blade 10 is stored in a waste toner storage chamber 9 formed by the cleaning blade 10 and the drum unit frame 5. The waste toner contained in the container chamber 9 is transported toward the rear of the apparatus main body 100 (downstream in the attachment / detachment direction of the process cartridge 1) by a waste toner transport screw 15 installed in the waste toner container chamber 9. The transported waste toner is discharged from a waste toner discharge portion (not shown) and delivered to a waste toner transport unit 23 of the apparatus main body 100.

[0035] The developing unit 6 has a developing frame 16 that supports various components within the developing unit 6. The internal space of the developing frame 16 is divided into a developing chamber 16a in which the developing roller 11 and the supply roller 17 are provided, and a toner storage chamber 16b as a developer storage section in which toner is stored and an agitating member 29 is provided inside.

[0036] The developing chamber 16a is provided with a developing roller 11, a supply roller 17, and a developing blade 28. The developing roller 11 carries toner and rotates in the direction of arrow E during image formation, conveying the toner to the photosensitive drum 7 by contacting the photosensitive drum 7. The developing roller 11 is rotatably supported by the developing frame 16 at both ends in its longitudinal direction (direction of rotation axis) by developing bearing units 34. The supply roller 17 is rotatably supported by the developing frame 16 by the developing bearing units 34 while in contact with the developing roller 11, and rotates in the direction of arrow F during image formation. Furthermore, a developing blade 28, which serves as a layer thickness regulating member for regulating the thickness of the toner layer formed on the developing roller 11, is disposed so as to abut against the surface of the developing roller 11.

[0037] The toner storage chamber 16b is provided with an agitating member 29 for agitating the stored toner T and transporting the toner to the supply roller 17 via the developing chamber communication port 16c. The agitating member 29 has a rotation shaft 29a parallel to the rotation axis direction of the developing roller 11 and an agitating sheet 29b that is a flexible sheet and serves as a transport member. One end of the agitating sheet 29b is attached to the rotation shaft 29a and the other end is a free end, and when the rotation shaft 29a rotates, the agitating sheet 29b rotates in the direction of arrow G, whereby the toner is agitated by the agitating sheet 29b.

[0038] The developing unit 6 has a developing chamber communication port 16c that communicates between the developing chamber 16a and the toner storage chamber 16b. In this embodiment, when the developing unit 6 is in a normal use position (position during use), the developing chamber 16a is located above the toner storage chamber 16b. The toner in the toner storage chamber 16b is pumped up by the stirring member 29 and supplied to the developing chamber 16a through the developing chamber communication port 16c.

[0039] Furthermore, the developing unit 6 is provided with a toner receiving port 40 at one end in the attachment / detachment direction (FIG. 5). At the top of the toner receiving port 40, there are disposed a receiving port seal member 45 and a toner receiving port shutter 41 that is movable in the front-to-rear direction when the process cartridge 1 is attached or detached. The receiving port seal member 45 is made of a fibrous member 45a made of polyester or the like and an elastic member 45b made of sponge or the like, and is fixed to the toner receiving port 40 by a fixing means such as double-sided tape. When the process cartridge 1 is not attached to the apparatus main body 100, the toner receiving port 40 is closed by the receiving port shutter 41. The receiving port shutter 41 is configured to open when it is urged by the apparatus main body 100 in conjunction with the attachment or detachment operation of the process cartridge 1.

[0040] When the process cartridge 1 is mounted in the apparatus main body 100, the receiving port seal member 45 comes into contact with the toner supply port (not shown) of the apparatus main body and is compressed in the W direction in FIG. 5. The elastic force generated by the compression of the receiving port seal member 45 seals the receiving port seal member 45 and the toner supply port, preventing toner from scattering around the toner receiving port 40. Toner discharged from the toner cartridge 13, which will be described later, is transported through a toner transport path (not shown) provided in the apparatus main body 100 and supplied to the process cartridge 1 via the toner receiving port 40.

[0041] 3, the developing unit 6 is provided with a receiving and conveying path 42 that communicates with the toner receiving port 40, and a receiving and conveying screw 43 is disposed inside the developing unit 6. Furthermore, a storage chamber communication port 44 for supplying toner to the toner storage chamber 16b is provided near the longitudinal center of the developing unit 6, and the receiving and conveying path 42 communicates with the toner storage chamber 16b. The receiving and conveying screw extends parallel to the rotational axes of the developing roller 11 and the supply roller 17, and is configured to convey the toner received through the toner receiving port 40 to the toner storage chamber 16b via the storage chamber communication port 44.

[0042] The developing unit 6 and drum unit 4 described above are coupled to each other so as to be able to swing about a predetermined rotation axis. More specifically, as shown in FIG. 6, holes 34a, 5a are provided at both longitudinal ends of the developing bearing unit 34 and the drum unit frame 5, respectively, and they are coupled via a rotation support pin 30. With regard to this swing shaft support configuration, FIG. 6 only shows one longitudinal side (one side), and a similar shaft support configuration is provided on the opposite side (the other longitudinal side). As a result, the developing unit 34 is supported to be able to swing relative to the drum unit 4, with the central axis 30c of the rotation support pin 30 (hereinafter referred to as the first rotation axis) serving as the axis.

[0043] The process cartridge 1 is provided with a pressure-receiving portion 38 for performing the pivotal movement due to the above-described support structure, and is configured so that the photosensitive drum 7 and the developing roller 11 can move toward or away from each other when an operating force is applied from the main body 100 of the apparatus. That is, during image formation, a pressing mechanism (not shown) provided in the main body 100 of the apparatus presses the pressure-receiving portion 38 provided on the developing frame 16, and a rotational moment in the direction K in FIG. 1 acts on the developing unit 6 with respect to the rotation support pin 30. This allows the developing unit 6 to take a first position (contact position or proximity position) in which the developing roller 11 is in contact with or proximity to the photosensitive drum 7. On the other hand, when the image formation process is completed and the pressure applied by the pressing mechanism of the main body 100 of the apparatus is released, the developing unit 6 is configured so that, due to its own weight, the developing roller 11 is moved away from the photosensitive drum 7 to a second position (separated position) in which the developing roller 11 is spaced apart from the photosensitive drum 7.

[0044] <Toner cartridge> The toner cartridge 13 according to this embodiment will be described with reference to Fig. 7. Fig. 7 is a cross-sectional view of the toner cartridge according to this embodiment.

[0045] The toner cartridge 13 includes a supply frame 50 that supports various components inside the toner cartridge 13, and a supply toner storage chamber 51 that stores toner inside. A supply toner stirring member 53 and a supply toner transport screw 54 are provided inside the supply toner storage chamber 51.

[0046] The supply toner agitating member 53 is disposed parallel to the longitudinal direction of the toner cartridge 13 and is rotatably supported by the supply frame 50. The supply toner agitating member 53 also has a rotating shaft 53a and a supply agitating and conveying sheet 53b made of a flexible sheet. The rotation of the rotating shaft 53a, which in turn rotates the supply agitating and conveying sheet 53b, conveys the toner to the supply conveying screw 54.

[0047] The replenishment toner transport screw 54 is disposed parallel to the rotation axis of the replenishment toner agitator 53 and is rotatably supported by the replenishment frame 50. The replenishment toner transport screw 54 rotates to transport the toner in the replenishment toner storage chamber 51 from front to rear (from upstream to downstream in the toner cartridge installation / removal direction). The transported toner is discharged from a toner discharge port provided downstream of the replenishment toner transport screw 54 into a toner transport path within the device main body 100. As described above, the toner discharged into the toner transport path within the device main body 100 is replenished into the development unit 16 via the toner receiving port 40 shown in FIG. 5.

[0048] <Coupling member at the end of the supply roller> The coupling configuration at the end of the supply roller in this embodiment will be described using FIGS. 1 and 8 to 13. FIG. 1 is a side view of the drive side of the process cartridge according to this embodiment, showing the photosensitive drum and the developing roller in a spaced-apart state. FIG. 8 is an exploded perspective view showing the coupling configuration of the developing unit in this embodiment. FIG. 9 is a perspective view showing the drive side of the process cartridge according to this embodiment. FIG. 10 is a side view of the drive side of the process cartridge according to this embodiment, showing the photosensitive drum and the developing roller in contact with each other. FIG. 11 is a schematic cross-sectional view of the drive mechanism between the main assembly of the apparatus and the process cartridge according to this embodiment, showing a disengaged state of the coupling. FIG. 12 is a schematic cross-sectional view of the drive mechanism between the main assembly of the apparatus and the process cartridge according to this embodiment, showing a state in which the coupling is engaged and the photosensitive drum and the developing roller are spaced apart. FIG. 13 is a schematic cross-sectional view of the drive mechanism between the main assembly of the apparatus and the process cartridge according to this embodiment, showing a state in which the coupling is engaged and the photosensitive drum and the developing roller are in contact with each other.

[0049] 11 to 13, the apparatus main body 100 is provided with a main body side drum drive coupling 107 and a main body side developing drive coupling 104 for transmitting a rotational drive force to the process cartridge 1. In contrast, the process cartridge 1 is provided with a drum coupling 67 and a coupling member 48 for receiving a rotational drive force from the main body side coupling.

[0050] 11 shows a state in which the process cartridge 1 is being attached to or detached from the apparatus main body 100, before the main body side developing drive coupling 104 and the coupling member 48, and the main body side drum drive coupling 107 and the drum coupling 67 are engaged with each other. When the process cartridge 1 is detached from the apparatus main body 100, the abutting portion (positioned portion) 49c of the coupling support member 49 supporting the coupling member 48 is abutted against the coupling holding portion (positioning portion) 33a of the drum support member 33 by the coupling pressing member 37. At this time, the rotation axis M5 of the coupling member 48 and the supply roller 17 The rotation axes M3 of the main body side developing drive coupling 104 and the main body side developing drive coupling 104 are maintained parallel to each other with a predetermined gap therebetween in a direction perpendicular to the axes. Here, the predetermined gap is set within a range in which the coupling member 48 can be moved to a parallel position where it engages with the main body side developing drive coupling 104 by a guide shape formed in an engaging portion of the main body side developing drive coupling 104 that engages with the coupling member 48. The coupling member 48, together with an intermediate member 47 and a drive transmission member 46 (to be described later), constitute a so-called Oldham coupling.

[0051] The process cartridge 1 is inserted into the process cartridge accommodating portion of the apparatus main body 100 with the longitudinal end on the drive side where the coupling is provided positioned first. As a result, as shown in FIG. 12, the coupling of the process cartridge 1 and the coupling of the apparatus main body 100 are engaged with each other, enabling drive transmission from the apparatus main body 100 to the process cartridge 1. At this time, due to the guide shape of the main body side developing drive coupling 104, the coupling member 48 moves parallel in a direction perpendicular to the rotation axis direction and engages with the main body side developing drive coupling 104, thereby separating the contact portion 49c of the coupling support member 49 from the coupling holding portion 33a of the drum support member 33. FIG. 12 shows a state in which the developing unit 6 (developing roller 11) is separated from the drum unit 4 (photosensitive drum 7) when the process cartridge 1 is mounted in the apparatus main body 100 (a state in which the couplings are engaged and mounting is complete). Figure 13 shows the state in which the process cartridge 1 is attached to the main body 100 of the apparatus (the state in which the couplings are engaged and attachment is complete), with the developing unit 6 (developing roller 11) abutting against the drum unit 4 (photosensitive drum 7).

[0052] The drum coupling 67 is provided at one longitudinal end of the photosensitive drum 7 to transmit a driving force to the photosensitive drum 7. The drum coupling 67 engages with a main body-side drum drive coupling 107, which serves as a drum drive output unit of the apparatus main body 100. The driving force of a drive motor (not shown) of the apparatus main body 100 is transmitted to the photosensitive drum 7 via the coupling, causing the photosensitive drum 7 to rotate in the direction of arrow A (see FIG. 3). The photosensitive drum 7 also has a drum flange (not shown) at the other longitudinal end. The charging roller 8 is rotatably supported by the drum unit frame 5 so as to contact the photosensitive drum 7 and rotate in response to the photosensitive drum 7. The rotation axis M1 of the photosensitive drum 7 is parallel to the longitudinal direction of the process cartridge 1 and the longitudinal direction of the drum unit 108.

[0053] The coupling member 48 is provided on one end side of the developing unit 6 in the longitudinal direction to transmit a driving force to the developing unit 6. The coupling member 48 is a member that engages with a main body side developing drive coupling 104 that serves as a developing drive output portion of the apparatus main body 100, and rotates upon receiving a rotational driving force from a drive motor (not shown) of the apparatus main body 100. The driving force received by the coupling member 48 is transmitted to the supply roller 17, and also to the developing roller 11 via a drive train (drive transmission gear 77, idler gear 76, developing roller drive gear 71) that serves as a drive transmission means provided in the developing unit 6. This allows the developing roller 11 to rotate in the direction of arrow E in FIG. 3, and the supply roller 17 to rotate in the direction of arrow F in FIG. 3.

[0054] As shown in FIGS. 8 and 11, in this embodiment, the coupling structure of the developing unit 6 is made up of a drive transmission member 46, an intermediate member 47, and a coupling member 48.

[0055] One end of the drive transmission member 46 engages with the end core metal portion 17a of the supply roller 17, and the other end has a protrusion 46a that is configured to engage with a first groove 47a of the intermediate member 47. The engagement portion (not shown) of the drive transmission member 46 that engages with the end core metal portion 17a is configured to engage with the end core metal portion 17a so that a rotational driving force is transmitted to the end core metal portion 17a. The intermediate member 47 has a first groove 47a and a second groove 47b that is perpendicular to the first groove 47a. The intermediate member 47 engages with both the coupling member 48 and the drive transmission member 46. The protrusion 46a of the drive transmission member 46 engages with the first groove 47a, and the protrusion 48a provided on the coupling member 48 engages with the second groove 47b. Each of these engagement portions is configured so that the direction (second direction) in which the first groove portion 47a and the protrusion portion 46a can slide relative to each other and the direction (first direction) in which the second groove portion 47b and the protrusion portion 48a can slide relative to each other are perpendicular to each other in phase around an axis parallel to the rotation axis M3 of the supply roller 17.

[0056] The coupling member 48 has a driven force transmission portion 48b as a driving force receiving portion at an end portion opposite, in the axial direction parallel to the rotation axis M3, to an end portion where a protrusion 48a that engages with the second groove portion 47b of the intermediate member 47 is provided. A driving force is transmitted to the driven force transmission portion 48b from a main body side developing device drive coupling 104 of the apparatus main body 100. The coupling member 48 has a supported portion 48c that is a shaft portion having the driven force transmission portion 48b at its tip, and the supported portion 48c is rotatably inserted into a shaft hole 49a of a coupling support member 49. In other words, the coupling member 48 is supported by the coupling support member 49 so as to be rotatable about an axis parallel to the rotation axis M3.

[0057] The coupling support member 49 is attached to the side cover member 52 by the latched portions 49b, 49d so as to be movable within a predetermined movable range in a direction perpendicular to the rotation axis M3. The side cover member 52 is fixed to the longitudinal end of the developing frame 16 of the developing unit 6 on the drive side.

[0058] The locked portion 49b is a boss (protrusion) that protrudes in a direction parallel to the rotation axis M3. The coupling support member 49 is inserted in a direction parallel to the rotation axis M3 through a locking portion 52a, which is a guide portion of an arc-shaped slot provided in the cover member 52. The direction in which the locking portion 52a guides the locked portion 49b is along a direction H along an arcuate path centered on the center of swing rotation (rotation support pin 30) between the developing unit 6 and the drum unit 4. The relationship between the locked portion 49b and the locking portion 52a may be reversed from that of this embodiment. That is, a convex portion serving as the locked portion may be provided on the side cover 52, and a guide portion into which the convex portion fits may be provided on the coupling support member 49. Even in this case, the guide path of the guide portion may be configured to form an arcuate path centered on the center of swing rotation (rotation support pin 30) between the drum unit 4 and the developing unit 6 when the abutting portion 49c of the coupling support member 49 is held (pressed and positioned) by a coupling holding portion 33a (described later).

[0059] Furthermore, the locked portion 49b, which is a plate-shaped portion protruding in a direction perpendicular to the rotation axis M3, is inserted in the moving direction into the locking portion 52b, which is a groove-shaped guide portion recessed in the same direction. With these engagement structures, the coupling support member 49 is locked to the side cover member 52, and is configured to be movable relative to the side cover member 52 (developing frame body 16) in a direction intersecting the rotation axis M3 within the movable range of each engagement structure.

[0060] That is, the coupling member 48 is allowed to move relative to the supply roller 17 in any direction on an imaginary plane perpendicular to the rotational axis M3 due to sliding at the concave-convex fitting portions provided between the drive transmission member 46, the intermediate member 47, and the coupling member 48. This relative movement is such that the rotational axis M4 of the coupling member 48 is displaced relative to the rotational axis M3 in a direction intersecting the rotational axis M3 while maintaining a state parallel to the rotational axis M3 of the supply roller 17. Furthermore, when the process cartridge 1 is removed from the main body 100 of the apparatus, the coupling support member 49 remains pressed (positioned) against the coupling member holding portion 33a by the pressing force of the coupling pressing member 37, as described below, even if the drum unit 4 and the developing unit 6 change their relative positions due to swinging. Furthermore, when the process cartridge 1 is attached to the main body 100 of the apparatus, the coupling support member 49 is separated from the coupling member holding portion 33a due to the engagement of the coupling member 48 with the main body-side developer drive coupling 104. As the supply roller 17 is displaced between the separated state (FIG. 12) and the contact state (FIG. 13) of the developing roller 11 and the photosensitive drum 7, the coupling member 48 maintains its engagement with the main body side developing drive coupling 104, and the drive transmission member 46 displaces integrally with the supply roller 17 (developing unit 6). In this state, the driving force transmitted from the main body side developing drive coupling 104 can be transmitted to the supply roller 17 by the rotation of the coupling member 48 and the sliding of the concave-convex fitting portions between the drive transmission member 46, the intermediate member 47, and the coupling member 48.

[0061] 1, 9, and 10, a drum support member 33 is provided at a longitudinal end of the drum support frame 36 to rotatably support the photosensitive drum 7. The drum support member 33 is provided with a coupling member holding portion 33a for holding the coupling support member 49 when the process cartridge 1 enters the apparatus main body 100, and a support portion 33b for supporting a coupling pressing member 37 (tension spring) described later. The coupling member holding portion 33a is provided so as to be able to come into contact with the coupling support member 49 in a direction intersecting with the rotation axis M2.

[0062] After the developing unit 6 is swingably supported by the drum unit 4, the coupling pressing member 37 is attached between the support portion 49e of the coupling support member 49 and the support portion 33b of the drum support member 33. In this embodiment, a tension spring is used as the coupling pressing member 37. The coupling pressing member 37 is disposed between the drum support member 33 to which one end is connected and the coupling support member 49 to which the other end is connected, and is positioned at a position intersecting the rotation axis M2 of the developing roller 11. The coupling pressing member 37 applies a pressing force that presses the coupling support member 49 against the coupling holding portion 33a in the insertion direction. When the process cartridge 1 is removed from the main body 100 of the apparatus, the pressing force of the coupling pressing member 37 causes the coupling support member 49 to be held and positioned by the coupling holding portion 33a, which serves as the positioning portion. As a result, as shown in FIG. 11 , the coupling member 48 supported by the coupling support member 49 can be positioned at a predetermined position (positioned at a fixed position). Therefore, when the process cartridge 1 is mounted in the main body 100 of the apparatus, the coupling member 48 can be stably engaged with the main body side developer drive coupling 104 of the main body 100 of the apparatus.

[0063] The coupling pressing member 37 is not limited to a biasing member such as a tension spring. Any other configuration may be used as long as it is capable of generating a pressing force (biasing force) between the drum support member 33 and the coupling support member 49 that presses the contact portion 49c of the coupling support member 49 against the coupling holding portion 33a in a direction intersecting the rotation axis M2. Furthermore, the direction in which the pressing force of the coupling pressing member 37 acts on the coupling support member 49 is a direction that moves the coupling 48 closer to the drum coupling 67, but the configuration is not limited to this.

[0064] As is clear from the above description, this embodiment employs an Oldham coupling system, so the coupling member 48 is movable in a direction intersecting the rotation axis of the supply roller 17. Therefore, as shown in FIGS. 12 and 13 , when the main assembly-side developer drive coupling 104 in the main assembly 100 is engaged with the coupling member 48, the developing unit 6 can move toward and away from the first and second positions. Furthermore, by providing the coupling pressing member 37 between the coupling support member 49 and the drum support member 33, the pressing force of the coupling pressing member 37 does not contribute to the moment force around the rotation support pin 30. In other words, even if the pressing force of the coupling pressing member 37 varies due to variations in component tolerances, this does not affect the moment force around the rotation support pin 30. As described above, in this embodiment, the developing roller 11 is brought into contact with the photosensitive drum 7 by the moment force around the rotation support pin 30 generated by the pressing member of the main assembly 100. Therefore, in this embodiment, in which the pressing force of the coupling pressing member 37 does not affect the moment force around the rotation support pin 30, it is possible to press the developing roller 11 against the photosensitive drum 7 stably.

[0065] In the conventional configuration, a pressing force (biasing force) acting in a direction pressing the coupling support member 49 against the coupling holding portion 33a is provided between the side cover member 52 (i.e., the developing device frame 16) and the coupling support member 49, for example, by a torsion coil spring. Here, when the process cartridge 1 is mounted in the main body 100 of the apparatus, the drum unit 4 and the coupling member 48 are positioned (supported) by the main body 100 of the apparatus. Therefore, the biasing force of the torsion coil spring acts on the developing device frame 16. When a contact / separation operation is performed in this state, the developing unit 6 is displaced with respect to the coupling member 48 positioned in the main body 100 of the apparatus, and the relative displacement between the coupling support member 49 and the developing device frame 16 changes the acting state of the torsion coil spring, generating a moment force during the contact / separation operation. In contrast, in this embodiment, a pressing force (biasing force) acting in a direction pressing the contact portion 49c of the coupling support member 49 against the coupling holding portion 33a is applied by a tension spring engaged with both the drum support member 33 (i.e., the drum unit frame 5) and the coupling support member 49 so as to connect them. With this configuration, the amount of change in the operating state of the coupling pressing member 37, which is a tension spring, is small in response to a change in the posture of the developing unit 6 due to contact / separation movement. Therefore, the moment force described above is unlikely to be generated. This stabilizes the contact / separation movement of the developing roller 11 with respect to the photosensitive drum 7, allowing the developing roller 11 to be stably pressed against the photosensitive drum 7.

[0066] In this embodiment, the present invention has been described as being applied to a process cartridge in which the Oldham coupling is provided at the end of the supply roller, but the process cartridge is not limited to this configuration, and the present invention can also be suitably applied to a process cartridge in which the Oldham coupling is provided at the end of the developing roller. [Explanation of symbols]

[0067] 1...process cartridge, 4...drum unit, 5...drum unit frame, 6...developing unit, 7...photosensitive drum, 11...developing roller, 16...developing frame, 17...supply roller, 30...rotation support pin, 33...drum support member, 36...drum support frame, 37...coupling pressing member, 38...pressed portion, 46...drive transmission member, 47...intermediate member, 48...coupling member, 49...coupling support member, 52...side cover member

Claims

1. A process cartridge detachably mountable to a main body of an image forming apparatus, a drum unit having a photosensitive drum and a drum frame that rotatably supports the photosensitive drum; A developing roller; a developing frame that rotatably supports the developing roller; a drive transmission unit including a rotatable coupling member provided at an end of the developing frame body in the direction of the rotation axis of the developing roller and for receiving a drive force for rotating the developing roller from the apparatus main body, and a rotatable drive transmission member for transmitting the drive force transmitted from the coupling member to the developing roller, wherein the coupling member and the drive transmission member are configured to be relatively movable in a direction intersecting the rotation axis; a support member that rotatably supports the coupling member and is provided so as to be movable relative to the developing frame and the drive transmission member in a direction intersecting the rotation axis; a developing unit including the developing frame and the drive transmission member configured to be movable integrally with the drum frame in a direction intersecting the rotation axis between a contact position where the developing roller contacts the photosensitive drum and a separation position where the developing roller is separated from the photosensitive drum; Equipped with the support member has a positioned portion, the drum frame has a positioning portion that abuts against the positioned portion of the support member in a direction intersecting the rotation axis to determine the position of the support member relative to the drum frame, A process cartridge characterized in that it has a biasing member that engages with both the support member and the drum frame so that a biasing force acts in the direction in which the positioned portion of the support member abuts against the positioning portion of the drum frame.

2. 2. A process cartridge according to claim 1, wherein the positioned portion of the support member abuts against the positioned portion of the drum frame, and the developing frame and the drive transmission member are in a spaced position.

3. 3. The process cartridge according to claim 2, wherein when the process cartridge is mounted in the apparatus main body, the developing frame and the drive transmission member are configured to be movable between the abutment position and the separated position when the positioned portion of the support member is separated from the positioning portion of the drum frame.

4. The process cartridge according to any one of claims 1 to 3, characterized in that the support member is configured to be movable relative to the developing frame in a direction along an arcuate trajectory centered on the center of rotation of the relative movement between the drum frame and the developing frame.

5. the support member has a protrusion that protrudes in a direction along the rotation axis, 5. A process cartridge according to claim 4, wherein said developing frame has a guide portion into which said convex portion fits in a direction along said rotation axis, said guide portion extending along said arcuate track.

6. the biasing member is a tension spring, 6. The process cartridge according to claim 1, wherein one end of the tension spring is connected to the drum frame and the other end is connected to the support member.

7. The developing roller has a gear at one end. The developing unit comprises: a developer accommodating portion provided in the developing frame and configured to accommodate a developer; a supply roller for supplying the developer accommodated in the developer accommodating portion to the developing roller, the supply roller having one end connected to the drive transmission member and supported by the developing frame so as to be rotatable about a second rotation axis extending in the direction of the rotation axis; a drive transmission means for transmitting a drive force from the drive transmission member to the gear of the developing roller; 7. The process cartridge according to claim 1, further comprising:

8. the drive transmission unit has an intermediate member between the coupling member and the drive transmission member in the direction of the rotation axis, the intermediate member engaging with both the coupling member and the drive transmission member, and is configured so that the driving force is transmitted from the coupling member to the drive transmission member via the intermediate member, The process cartridge according to any one of claims 1 to 7, characterized in that the intermediate member is configured to be movable relative to the coupling member in a first direction perpendicular to the direction of the rotation axis, and to be movable relative to the drive transmission member in a second direction perpendicular to the direction of the rotation axis and the first direction.

9. the drum unit has a drum coupling provided at an end of the drum frame on the same side as the coupling member in the direction of the rotation axis of the photosensitive drum, for receiving a driving force for rotating the photosensitive drum from the device main body; 9. The process cartridge according to claim 1, wherein the biasing force of the biasing member acts on the support member in a direction that moves the coupling member closer to the drum coupling.

Images