cartridge

Abstract

To provide a cartridge having a configuration for suppressing reduction in strength of a frame having a hole for exposing a memory means.SOLUTION: The cartridge includes a drum unit and a developing unit configured to be detachably attached to the drum unit. An exposure hole 68a for exposing a memory of a developing unit is formed in a frame 610 of a drum unit. In the rotational axis direction of the photosensitive drum 61, a recessed portion 800 is disposed adjacent to the 68a of the exposure hole.SELECTED DRAWING: Figure 17

Description

[Technical Field]

[0001] The present invention relates to a cartridge and an image forming apparatus in which a developing unit is detachably attached to a drum unit. [Background technology]

[0002] Conventionally, a process cartridge has been proposed in which a developing cartridge having a memory means is detachably mounted on a photosensitive cartridge (see Patent Document 1). This photosensitive cartridge is provided with a first electrical contact portion that electrically connects with an electrical contact portion on the main body of the apparatus, and a second electrical contact portion that electrically connects with the memory means. The memory means is configured to communicate with a control unit provided on the main body of the apparatus via these first and second electrical contact portions. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-224221 Summary of the Invention [Problem to be solved by the invention]

[0004] As described in Patent Document 1, when a memory means is provided in a developing cartridge that is detachable from the frame of a photosensitive cartridge, it is possible to configure the memory means to be in direct contact with the electrical contacts on the main body of the device. In this case, it is necessary to provide a hole in the frame to expose the memory.

[0005] However, providing holes in the frame reduces the strength of the frame.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a cartridge and an image forming apparatus that are provided with a structure that prevents a decrease in strength of a frame having a hole for exposing a memory means. [Means for solving the problem]

[0007] One aspect of the present invention is a cartridge that is detachably attached to the main body of an image forming device, comprising: a drum unit having a photosensitive drum and a frame that rotatably supports the photosensitive drum; a developing roller that supplies toner to the photosensitive drum; and a memory for storing information, and a developing unit that is detachably attached to the drum unit, wherein the drum unit has a cleaning member that contacts an end of the photosensitive drum in the direction of the rotation axis to clean the photosensitive drum, and the frame has an exposure hole for exposing the memory from the frame and a recess adjacent to the exposure hole in the direction of the rotation axis of the photosensitive drum, and the recess is arranged so that at least a portion of the recess overlaps with the cleaning member in the direction of the rotation axis when viewed from a direction perpendicular to the direction of the rotation axis, and is recessed in a direction away from the cleaning member. [Effects of the Invention]

[0008] According to the present invention, the recess is provided adjacent to the exposure hole for exposing the memory from the frame in the direction of the rotation axis of the photosensitive drum, thereby increasing the frame strength around the exposure hole of the drum unit. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic view showing an entire printer according to a first embodiment. [Figure 2] FIG. 2 is a perspective view showing a drum unit and a developing unit. [Figure 3] FIG. [Figure 4] FIG. 4 is a cross-sectional view showing the 4-4 section of FIG. 3. [Figure 5] FIG. [Figure 6] FIG. [Figure 7]1A is a side view showing an unused developing unit, and FIG. 1B is a side view showing a used developing unit. [Figure 8] FIG. [Figure 9] FIG. 2 is a cross-sectional view showing the process cartridge. [Figure 10] FIG. 2 is a perspective view showing a process cartridge. [Figure 11] FIG. 2 is a perspective view showing a process cartridge. [Figure 12] FIG. 2 is a plan view showing the drum unit and the developing unit. [Figure 13] 1A is a plan view showing a pressing member and a lifting member, with the lifting member indicated by a dashed line, and FIG. 1B is a plan view showing a pressing member and a lifting member, with the lifting member indicated by a solid line. [Figure 14] (a) is a bottom view of the drum unit. (b) is an enlarged view of the rear left end of the drum unit. [Figure 15] FIG. [Figure 16] 1A is a cross-sectional view showing a state in which the developing unit is attached to the drum unit, and FIG. 1B is a cross-sectional view showing the developing unit in a lifted-up state by a lift member. [Figure 17] (a) is an enlarged view showing the rear left end of the drum unit, and (b) is a cross-sectional view of the collection recess. [Figure 18] FIG. 10 is a perspective view showing a process cartridge according to a second embodiment. [Figure 19] FIG. 2 is a perspective view showing a process cartridge. [Figure 20] FIG. [Figure 21] FIG. [Figure 22] FIG. 4 is an enlarged view showing the rear left end side of the drum unit. [Figure 23] FIG. 4 is a plan view showing the rear left end side of the drum unit. [Figure 24] FIG. 4 is a plan view showing the rear left end side of the drum unit. [Figure 25] FIG. 11 is a bottom view showing a process cartridge according to a third embodiment. [Figure 26] (a) is a schematic diagram showing the electrode unit on the device body side, and (b) is a cross-sectional view showing the electrode unit on the device body side. [Figure 27] 1A is a cross-sectional view showing the electrode unit when the development unit is moving in the direction of attachment of the drum unit, and FIG. 1B is a cross-sectional view showing the electrode unit when the development unit has been attached to the drum unit. [Figure 28] 10A is a perspective view showing a drum unit according to a fourth embodiment, and FIG. 10B is a perspective view of the drum unit of FIG. [Figure 29] 1A is a perspective view of the developing unit, and FIG. 1B is a perspective view of the developing unit as viewed from below. [Figure 30] 1A is a perspective view of a process cartridge, and FIG. 1B is a cross-sectional view of the process cartridge. [Figure 31] 1 is a schematic diagram showing an overall configuration of a printer. [Figure 32] 10A is a perspective view showing a drum unit according to a fifth embodiment, and FIG. 10B is a perspective view of the drum unit of FIG. [Figure 33] 1A is a perspective view of the developing unit, and FIG. 1B is a perspective view of the developing unit as viewed from below. [Figure 34] 1A is a perspective view of a process cartridge, and FIG. 1B is a cross-sectional view of the process cartridge. [Figure 35] FIG. 13 is a cross-sectional view showing a process cartridge according to a sixth embodiment. [Figure 36] FIG. 2 is a schematic diagram showing a state in which the process cartridge is mounted in the apparatus main body. [Figure 37] 1A is a perspective view showing a process cartridge, and FIG. 1B is an enlarged view showing the rear left end side of the process cartridge shown in FIG. [Figure 38] 1A is a perspective view of the developing unit, and FIG. 1B is an enlarged view of the left rear end of the developing unit shown in FIG. [Figure 39] 1A is a perspective view of the drum unit, and FIG. 1B is an enlarged view of the rear left end of the drum unit shown in FIG. [Figure 40] 1A is a schematic diagram showing a guide configuration on the left side of the main body of the apparatus, and FIG. 1B is a perspective view showing the left side of the process cartridge. [Figure 41] 1A is a schematic diagram showing a guide configuration on the right side of the main body of the apparatus, and FIG. 1B is a perspective view showing the right side of the process cartridge. [Figure 42] FIG. 4 is an explanatory diagram for explaining the meshing structure of a first photosensitive drum gear. [Figure 43] FIG. 10 is an explanatory diagram for explaining the action of a thrust force generated by a first photosensitive drum gear. [Figure 44] 13A is a perspective view showing a drum unit according to a seventh embodiment, and FIG. 13B is an enlarged view showing the structure around the photosensitive drum of the drum unit of FIG. [Figure 45] FIG. 3 is an assembly diagram illustrating a power transmission structure around the photosensitive drum. [Figure 46] 13A is a perspective view showing a process cartridge according to an eighth embodiment, and FIG. 13B is a schematic view showing a state in which the process cartridge is mounted in the main assembly of the apparatus. [Figure 47] 13A is a perspective view of a process cartridge according to a ninth embodiment, as viewed from below, and FIG. 13B is an explanatory diagram illustrating the relationship between a drum unit memory and a guide. [Figure 48] 19A is a perspective view showing a process cartridge according to a tenth embodiment, and FIG. 19B is a side view of the process cartridge. [Figure 49] 1A is a schematic diagram showing the process cartridge with the door open, and FIG. 1B is a schematic diagram showing the process cartridge with the door closed. [Figure 50] 1A is a perspective view of the left end side of the process cartridge as viewed from below, and FIG. 1B is a bottom view of the process cartridge. [Figure 51] 10A is a perspective view of the left end side of a process cartridge according to a modified example, viewed from below, and FIG. [Figure 52] 10A is a perspective view of the left end side of a process cartridge according to a modified example, viewed from below, and FIG. [Figure 53] 10A is a perspective view of the left end side of a process cartridge according to a modified example, viewed from below, and FIG. [Figure 54] FIG. 23 is a perspective view of a developing unit according to an eleventh embodiment. [Figure 55] FIG. 2 is a perspective view showing a process cartridge. [Figure 56] FIG. 29 is a cross-sectional view showing a process cartridge according to a twelfth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] First Embodiment [Overall configuration] First, a first embodiment of the present invention will be described. In the following description, directions are defined relative to the user using the printer 1. That is, the front side of the printer 1 is referred to as the "front," the rear side as the "rear," the top side as the "upper," and the bottom side as the "lower." Furthermore, when viewing the printer 1 from the front side, the left side of the image forming apparatus is referred to as the "left," and the right side as the "right." The directions of the process cartridge, which will be described later, are also defined in the same manner as the printer 1, assuming that the cartridge is in the same position as when it is installed in the printer 1. Directions in each drawing are defined by arrows shown in the drawing. For example, in FIG. 1, the left side of the page is the front. Furthermore, the up-down direction is parallel to the vertical direction, and the left-right and front-to-back directions are parallel to the horizontal direction. The left-right direction is parallel to the rotational axis of the photosensitive drum 61 and the rotational axis of the developing roller 71, respectively.

[0011] The printer 1 as an image forming apparatus according to the first embodiment is an electrophotographic laser beam printer. As shown in Fig. 1, the printer 1 has a sheet feeding section 3 that supplies sheets S stored in a cassette 31, an image forming section 9 that forms a toner image on the sheet S, a fixing device 8 that fixes the toner image on the sheet S, and a pair of discharge rollers 25.

[0012] The sheet feeding section 3 has a cassette 31, a pickup roller 33 that feeds the uppermost sheet S stored in the cassette 31, and a pair of separation rollers 32 that separates the sheets S fed by the pickup roller 33 one by one.

[0013] The image forming unit 9 has an exposure device 4 provided in the device main body 2 of the printer 1, and a process cartridge 5 that is inserted into the device main body 2 in the direction of arrow S1 and removed in the direction of arrow S2. The exposure device 4 has a laser emission unit, a polygon mirror, a lens, a reflecting mirror, etc. (not shown). In this exposure device 4, a laser beam based on image data emitted from the laser emission unit is scanned at high speed over the surface of a photosensitive drum 61 of the process cartridge 5, thereby exposing the surface of the photosensitive drum 61.

[0014] The process cartridge 5 is disposed below the exposure device 4, and is inserted into or removed from the apparatus main body 2 when the door 21 of the apparatus main body 2 is open. The process cartridge 5 mainly has a drum unit 6 and a developing unit 7. The drum unit 6 has a photosensitive drum 61, a charging roller 62, a transfer roller 63, a cleaning blade 64, etc. The photosensitive drum 61 and the transfer roller 63 form a transfer nip N1. The developing unit 7 has a developing roller 71, a supply roller 72, a blade 73, a toner container 74 that contains a developer including toner, and a first agitator 75A and a second agitator 75B provided in the toner container 74.

[0015] The developer in the toner storage section 74 is agitated by the second agitator 75B and the first agitator 75A, and then supplied to the developing roller 71 by the supply roller 72. The developer supplied to the developing roller 71 by the supply roller 72 passes through the gap between the developing roller 71 and the blade 73, and is carried on the developing roller 71 in a constant layer thickness. The fixing device 8 is disposed behind the process cartridge 5, and has a pressure roller 91 and a heating roller 92. The heating roller 92 has a built-in heat source such as a ceramic heater.

[0016] When an image formation command is output to the printer 1, the image forming unit 9 starts an image formation process based on image information input from an external computer connected to the printer 1 or an image reading device connected as an option. The exposure device 4 irradiates the photosensitive drum 61 with laser light based on the input image information. At this time, the photosensitive drum 61 is pre-charged by a charging roller 62 serving as a charger, and an electrostatic latent image is formed on the photosensitive drum 61 by the irradiation of the laser light. Thereafter, the developing roller 71 develops this electrostatic latent image, forming a toner image on the photosensitive drum 61.

[0017] In parallel with the image forming process described above, sheets S stacked in cassette 31 are sent out by pickup roller 33. The sheets S fed by pickup roller 33 are separated one by one by separation roller pair 32 and transported to transfer nip N1. In transfer nip N1, a transfer bias is applied to transfer roller 63, so that the toner image formed on photosensitive drum 61 is transferred to sheet S. Sheet S onto which the toner image has been transferred in transfer nip N1 is heated and pressurized by fixing nip N2 formed by pressure roller 91 and heating roller 92, so that the toner image is fixed. Then, sheet S onto which the toner image has been fixed is discharged to discharge tray 22 by discharge roller pair 25.

[0018] [Process cartridge] 2, the process cartridge 5 has a drum unit 6 and a developing unit 7 that is detachably supported on the drum unit 6. The developing unit 7 is attached to the drum unit 6 in an attachment direction AD while the user grips a grip portion 701.

[0019] [Developing unit] 3 to 5, the developing unit 7 has a housing 700, a developing roller 71, a supply roller 72, a first agitator 75A, a second agitator 75B, a drive train 720, and a side holder 719. The housing 700 has a left side wall 704 and a right side wall 705 that rotatably support both ends of the developing roller 71, the supply roller 72, the first agitator 75A, and the second agitator 75B, respectively, and a grip portion 701 that is provided on the front side of the housing 700 and is gripped by a user. The side holder 719 covers the drive train 720 and is supported by the left side wall 704. In the following description, the direction of the rotational axis of the developing roller 71 will be referred to as the axial direction.

[0020] The first agitator 75A has an agitating rod 78A and an agitating sheet 79A, which agitate the developer in the toner storage unit 74. Similarly, the second agitator 75B has an agitating rod 78B and an agitating sheet 79B, which agitate the developer in the toner storage unit 74. The developer is supplied to the supply roller 72 by the agitating sheet 79A.

[0021] The developing roller 71 is rotatably supported by a bearing 746A provided in the side holder 719 and a bearing 746B attached to the right side wall 705 of the housing 700. As shown in FIG. 3, the developing unit 7 has a first contact 720A and a second contact 720B disposed near the bearing 746B. The first contact 720A is electrically connected to the developing roller 71, and a voltage applied to the developing roller 71 is supplied from the apparatus main body 2. The second contact 720B is electrically connected to the supply roller 72, and a voltage applied to the supply roller 72 is supplied from the apparatus main body 2. The first contact 720A and the second contact 720B are capable of contacting a power supply contact (not shown) provided in the apparatus main body 2.

[0022] 5 and 6, the drive train 720 provided on the left side of the developing unit 7 includes a development coupling 710, a supply roller gear 712, a developing roller gear 711, a first agitator gear 713, and a second agitator gear 714. The drive train 720 also includes idle gears 715A, 715B, and 715C.

[0023] The developing coupling 710 is rotatably supported on the left side wall 704 of the developing unit 7, and a drive transmission member (not shown) provided on the main body 2 of the apparatus engages with the developing coupling 710 in conjunction with the closing of a door 21 (see FIG. 1) provided on the main body 2 of the apparatus. Conversely, the drive transmission member moves away from the developing coupling 710 in conjunction with the opening of the door 21. The drive transmission member is configured to transmit a driving force to the developing coupling 710 while allowing for positional deviation of the developing coupling 710 within a predetermined range. In addition, the developing coupling 710, the developing roller gear 711, and the supply roller gear 712 are restricted from axial movement by a side holder 719.

[0024] When the apparatus main body 2 operates after the door 21 is closed, a driving force is transmitted from the drive transmission member to the developing coupling 710, causing a gear 710a provided on the circumferential surface of the developing coupling 710 to rotate. The gear 710a is engaged with a developing roller gear 711 and a supply roller gear 712 provided on the end of the supply roller 72, and the rotation of this gear 710a causes the developing roller 71 and the supply roller 72 to rotate.

[0025] Furthermore, the gear 710a of the development coupling 710 meshes with an idle gear 715A which meshes with the first agitator gear 713, and the first agitator 75A rotates when the first agitator gear 713 rotates. An idle gear 715B provided coaxially with the first agitator 75A meshes with an idle gear 715C which meshes with the second agitator gear 714, and the second agitator 75B rotates when the second agitator gear 714 rotates.

[0026] 5 to 7(b), the second agitator gear 714 is configured to be able to mesh with the gear portion 82 of the detection gear 81. The detection gear 81 is provided with a detection protrusion 83 that is located a predetermined distance from the center of rotation and extends in the axial direction, and the detection protrusion 83 penetrates a hole 84 in the detection portion 80 of the side holder 719. The hole 84 has an elongated hole shape that is long in the circumferential direction. The apparatus main body 2 is provided with a detection mechanism (not shown) that detects the position of the detection protrusion 83, and this makes it possible to determine whether the developing unit 7 is unused or has already been used.

[0027] Figure 7(a) is a side view showing an unused developing unit 7, and Figure 7(b) is a side view showing a developing unit 7 that has already been used. The detection gear 81 is a missing-tooth gear and has a gear portion 82 and a non-gear portion 82a. As shown in Figure 7(a), the second agitator gear 714 of the unused developing unit 7 is engaged with the gear portion 82 of the detection gear 81. At this time, the detection protrusion 83 is positioned on the upper front side.

[0028] When the developing unit 7 is used and the second agitator gear 714 rotates in the direction of arrow R3, the detection gear 81 meshing with the second agitator gear 714 rotates in the direction of arrow R4. Then, as shown in Figure 7(b), when the gear portion 82 of the detection gear 81 is no longer meshed with the second agitator gear 714, the detection gear 81 stops. At this time, the detection protrusion 83 is positioned on the upper rear side.

[0029] In this way, when the developing unit 7 is used, the detection protrusion 83 rotates within the range of the hole 84 of the detection part 80, and the position of the detection protrusion 83 is detected by a detection mechanism provided in the device main body 2. This makes it possible to determine whether the developing unit 7 is unused or has already been used.

[0030] 8, the bottom surface of the developing unit 7 is provided with a pair of left and right ribs 718, 718 protruding downward, a memory 85, and a positioning protrusion 86 located on the left side of the bottom surface. More specifically, the memory 85 and the positioning protrusion 86 are provided on the bottom surface of a side holder 719 of the developing unit 7. The memory 85 has a memory chip (not shown) that stores information about the developing unit 7, such as information about the amount of remaining toner, and a memory electrode 85a that is electrically connected to the memory chip. The memory electrode 85a contacts an electrode (not shown) provided in the main body 2 of the apparatus, and communicates between the memory chip and a control unit of the main body 2. In the direction of the rotational axis of the developing roller 71, the developing coupling 710 and the memory 85 are located on the same side of the center of the developing roller 71.

[0031] [Drum unit] Next, we will explain the detailed configuration of the drum unit 6. As shown in Figures 2 and 9 to 11, the drum unit 6 mainly has a frame 610 and a photosensitive drum 61 rotatably supported at the rear of the frame 610. The frame 610 has a pair of left and right walls 611 and 612 standing upright at the left and right ends of a bottom 614 so as to face each other in the left-right direction, and a front end wall 613 standing upright at the front end and provided with a grip 617 to be gripped by a user.

[0032] The photosensitive drum 61 is rotatably supported on the left and right side walls 611, 612 at the rear side of the frame 610, and is configured to cover the periphery of the photosensitive drum 61. Moreover, above the photosensitive drum 61, the frame 610 is formed with a laser passing hole 616, through which the surface of the photosensitive drum 61 can be irradiated with laser light emitted from the exposure device 4.

[0033] On the other hand, the frame 610 is configured to be open upward on the front side of the photosensitive drum 61, and has a mounting portion 615 for mounting the developing unit 7. More specifically, on the front side of the photosensitive drum 61, the space surrounded by the walls 611, 612, 613, and 614 forms the mounting portion 615 for mounting the developing unit 7.

[0034] 9, in the mounting portion 615, the bottom 614 is configured so that the front bottom 614F is one step lower than the rear bottom 614R that is closer to the photosensitive drum 61. The front bottom 614F forms a space in the mounting portion 615 in which the toner containing portion 74 of the developing unit 7 is contained, and a pair of left and right protrusions 643, 643 are formed on the upper surface thereof that faces the bottom surface of the developing unit 7.

[0035] On the other hand, the rear bottom 614R, which is closer to the photosensitive drum 61 than the front bottom 614F, forms a space in the mounting portion 615 to accommodate the developing roller 71 and the supply roller 72. Because of this configuration, when the developing unit 7 is mounted to the drum unit 6, it is inclined downward from the front side toward the rear side where the photosensitive drum 61 is present. Also, a space is formed between the front bottom 614F and the portion of the housing 700 that forms the toner storage portion 74 protrudes downward, allowing the internal toner storage capacity to be increased.

[0036] At the rear side of the frame 610, a first positioning protrusion 660 and a first guide rib 662 protruding axially outward are provided on the outer surface of the left wall 611, with the first positioning protrusion 660 being located rearward of the first guide rib 662. Similarly, a second positioning protrusion 661 and a second guide rib 663 protruding axially outward are provided on the outer surface of the right wall 612 of the frame 610, with the second positioning protrusion 661 being located rearward of the second guide rib 663. The first positioning protrusion 660 and the second positioning protrusion 661 are cylindrical, and the first guide rib 662 and the second guide rib 663 extend in the front-rear direction. When the process cartridge 5 is installed in the apparatus main body 2, the first positioning protrusion 660, the second positioning protrusion 661, the first guide rib 662, and the second guide rib 663 are guided by guide portions (not shown) provided in the apparatus main body 2. These guide portions then guide the process cartridge 5 to the installation position.

[0037] The lifespan of the developing unit 7, which is determined by the amount of toner contained in the developing unit 7, is set to be shorter than the lifespan of the drum unit 6, which is determined by the thickness of the photosensitive layer of the photosensitive drum 61. Therefore, from a cost perspective, it is desirable to replace only the developing unit 7 that has reached the end of its life separately from the drum unit 6. When replacing only the developing unit 7, open the door 21, remove the process cartridge 5 from inside the apparatus main body 2, and then remove only the developing unit 7 from the drum unit 6. Then, insert the new developing unit 7 in the installation direction AD in FIG. 2, and assemble the developing unit 7 to the drum unit 6.

[0038] Next, a positioning configuration of the developing unit 7 relative to the drum unit 6 when the developing unit 7 is assembled to the drum unit 6 will be described. First, a description will be given of the positioning of the developing unit 7 relative to the drum unit 6 in the front-to-rear direction. As shown in FIGS. 2, 10, and 11, receiving portions 641, 641 are formed on the left side wall 611 and the right side wall 612 of the frame 610, respectively, and the receiving portion 641 is configured to be able to abut against the bearings 746A, 746B of the developing unit 7. The receiving portion 641 is formed in a substantially U-shape with an open front, and has a lower surface 641a extending in the front-to-rear direction and an abutment surface 641b extending in the vertical direction (see FIG. 10).

[0039] 12 to 13(b), a pair of pressing members 640, 640 are provided at the front of the frame 610 of the drum unit 6. The pressing members 640 are biased forward by a biasing spring 644, and press a pair of pressed ribs 716 provided on the housing 700 of the developing unit 7 when the developing unit 7 is attached to the drum unit 6.

[0040] As shown in Figure 12, the pair of left and right pressed ribs 716 are arranged so that the pressed rib 716 located on the right side is positioned further rearward than the pressed rib 716 located on the left side. This is because, as shown in Figures 13(a) and 13(b), a lift member 642 (described later) is positioned so as to overlap the pressed rib 716 on the right side in the left-right direction, so that the lift member 642, which is rotated, does not interfere with the pressed rib 716 on the right side. With this configuration, the amount of rearward protrusion of the lift member 642 is reduced, and the process cartridge 5 can be made compact.

[0041] 2, when the developing unit 7 is attached to the drum unit 6 in the attachment direction AD, the bearings 746A and 746B of the developing unit 7 are guided by the lower surface 641a of the receiving portion 641. Then, when the developing unit 7 is further attached to the drum unit 6, the bearings 746A and 746B abut against the abutment surface 641b of the receiving portion 641.

[0042] In this state, when the user releases the grip portion 701 of the developing unit 7, the developing unit 7 is supported by the protrusions 643, 643 formed on the bottom 614 of the drum unit 6, and is pressed forward by the pressing member 640. The biasing force of the biasing spring 644 that presses the pressing member 640 presses the bearings 746A, 746B of the developing unit 7 against the abutment surface 641b, and the developing unit 7 is positioned in the front-to-rear direction with respect to the drum unit 6. In addition, the biasing force of the biasing spring 644 presses the developing roller 71 of the developing unit 7 against the photosensitive drum 61.

[0043] Next, a description will be given of a positioning mechanism for the developing unit 7 relative to the drum unit 6 in the left-right direction (the direction of the rotation axis of the photosensitive drum 61). As shown in Figures 12, 14(a) and 14(b), a rear bottom portion 614R of the bottom portion 614 of the frame 610 is provided with a sheet passing hole 618 through which a sheet passes when transported to the transfer nip N1, and an end through-hole 68.

[0044] The end through-hole 68 is provided at one end of the photosensitive drum 61 in the rotational axis direction (the left side in this embodiment), and is formed by an electrode exposure hole 68a and a positioning hole 68b. A first photosensitive drum gear 65 and a second photosensitive drum gear 66 are provided at the left end of the photosensitive drum 61, and a transfer gear 67 meshing with the second photosensitive drum gear 66 is provided at the left end of the transfer roller 63. When the process cartridge 5 including the drum unit 6 is installed in the apparatus main body 2, a drive gear provided in the apparatus main body 2 meshes with the first photosensitive drum gear 65. When the drive gear rotates in this state, the drive gear rotates the first photosensitive drum gear 65, and the photosensitive drum 61 and the second photosensitive drum gear 66 rotate integrally with the first photosensitive drum gear 65. The rotation of the second photosensitive drum gear 66 is transmitted to the transfer gear 67, and the transfer roller 63 rotates integrally with the transfer gear 67.

[0045] The electrode exposure hole 68a is configured so that, when the developing unit 7 is attached to the drum unit 6, the memory electrode 85a is exposed below the drum unit 6 and the memory electrode 85a can come into contact with an electrode (not shown) provided in the apparatus main body 2. The positioning hole 68b is formed to be continuous with the electrode exposure hole 68a on the rear side of the electrode exposure hole 68a, and is a slit-shaped hole that is smaller in size in the left-right direction than the electrode exposure hole 68a. When the developing unit 7 is attached to the drum unit 6, the positioning protrusion 86 engages with this positioning hole 68b, and the left-right position of the developing unit 7 is determined by this engagement of the positioning protrusion 86.

[0046] The connection between the electrode exposure hole 68a and the positioning hole 68b is formed by a tapered surface 681 that narrows toward the positioning hole 68b so as to guide the positioning protrusion 86 into the positioning hole 68b. As described above, the positioning protrusion 86 and the positioning hole 68b are located downstream of the memory electrode 85a and the electrode exposure hole 68a, respectively, in the mounting direction AD. Therefore, when the developing unit 7 is mounted to the drum unit 6, the memory electrode 85a does not come into contact with the drum unit 6. This improves usability when mounting the developing unit 7 to the drum unit 6 and reduces damage to the memory electrode 85a. Furthermore, because the electrode exposure hole 68a is located close to the positioning hole 68b, the positioning accuracy between the memory electrode 85a and the electrode exposure hole 68a is improved. Additionally, the positioning protrusion 86 can be easily guided into the positioning hole 68b via the electrode exposure hole 68a and engaged with it.

[0047] [Developing unit removal configuration] Next, a configuration for removing the developing unit 7 from the drum unit 6 will be described. Note that in FIG. 13(a), the lift member 642 shown in FIG. 13(b) is represented by a dotted line. As shown in FIGS. 13(a) and 13(b), a lift member 642 is provided at the front and right ends of the drum unit 6. As shown in FIG. 15, the lift member 642 is supported on the right side wall 612 of the drum unit 6 so as to be rotatable about a rotation axis 642X. The rotation axis 642X extends parallel to the rotation axes of the photosensitive drum 61 and the developing roller 71. The lift member 642 is biased by a compression spring 650 to rotate in the direction of arrow R1. By pressing downward an operating portion 642A provided at one end of the lift member 642, the lift member 642 is rotated in the direction of arrow R2 against the biasing force of the compression spring 650.

[0048] A cylindrical protrusion 751 that protrudes to the right is provided on the right side wall 705 of the developing unit 7, and a contact portion 642B that can come into contact with the protrusion 751 is provided on the other end of the lift member 642. The contact portion 642B is provided on the opposite side of the rotation axis 642X from the operation portion 642A.

[0049] 15 to 16(b), the pressing member 640 has a pressing surface 640a that is provided on the front surface of the pressing member 640 and extends in the vertical direction, and an inclined surface 640b that slopes upward and rearward from the upper end of the pressing surface 640a. The pressed portion 716 of the developing unit 7 has a pressed surface 716a that is pressed forward by the pressing surface 640a, and an inclined surface 716b that slopes downward and forward from the lower end of the pressed surface 716a.

[0050] 16(a), when the developing unit 7 is attached to the drum unit 6, the pressing surface 640a of the pressing member 640, which is biased by the biasing spring 644, presses the pressed surface 716a of the pressed portion 716 of the developing unit 7. At this time, the pressing surface 640a and the pressed surface 716a extend in a substantially vertical direction, and the biasing force of the biasing spring 644 acts perpendicularly to the pressed surface 716a, biasing the developing unit 7 forward. As a result, the developing unit 7 is locked in the attached position so that it will not come off the drum unit 6.

[0051] 15, when the operating portion 642A of the lift member 642 is pressed downward, the lift member 642 rotates in the direction of arrow R2, and the contact portion 642B of the lift member 642 pushes the protruding portion 751 of the developing unit 7 upward. As a result, as shown in FIG. 16(b), the front side of the developing unit 7 attached to the drum unit 6 rotates upward, and the developing unit 7 rotates in the removal direction LD from the attached position. As a result, the pressed surface 716a of the developing unit 7 moves upward away from the pressing surface 640a, and the inclined surface 716b of the developing unit 7 rides up on the inclined surface 640b of the pressing member 640.

[0052] At this time, the bearings 746A and 746B of the developing unit 7 are supported by the receiving portions 641. This state of the developing unit 7 is referred to as the lifted-up state. When the developing unit 7 is in the lifted-up state, the inclined surfaces 640b and 716b are inclined with respect to the forward direction, which is the biasing direction of the pressing member 640. That is, when the developing unit 7 is rotated in the removal direction LD by the lift member 642, the pressed surface 716a of the developing unit 7 moves upward away from the pressing surface 640a. Then, the inclined surface 716b of the developing unit 7 is lifted upward by the inclined surface 640b of the pressing member 640, which is biased forward by the biasing spring 644, and the developing unit 7 further rotates in the removal direction LD due to the biasing force of the biasing spring 644. This reduces the operating force required to place the developing unit 7 in the lifted-up state.

[0053] When the developing unit 7 is in the lifted-up state, most of the forward biasing force of the biasing spring 644 is converted into a substantially upward force by the inclined surfaces 640b and 716b, and therefore the developing unit 7 is not locked to the drum unit 6. Therefore, the user can remove the developing unit 7 from the drum unit 6 simply by lifting the grip portion 701 of the developing unit 7, without having to move any other members. In this way, the user can remove the developing unit 7 from the drum unit 6 and install a new developing unit 7 in the drum unit 6.

[0054] [Collection recess] Next, the configurations of the collecting recess 800 and the sheet member 810 will be described with reference to Figures 17(a) and 17(b). As shown in Figure 17(a), the frame 610 of the drum unit 6 has a bridge portion 619 provided between the end through-hole 68 and the sheet passing hole 618 at one end side (the left side in this embodiment) in the rotational axis direction of the photosensitive drum 61. The collecting recess 800 is provided in this bridge portion 619, and a sheet member 810 serving as a cleaning member is provided at the end of the collecting recess 800 on the photosensitive drum 61 side.

[0055] This sheet member 810 stands from the frame 610 toward the photosensitive drum 61, and its tip portion 810a is adapted to abut against the photosensitive drum 61. More specifically, the sheet member 810 abuts against the photosensitive drum 61 at an end portion that is axially outwardly spaced from the image forming area of ​​the photosensitive drum 61, and the tip portion 810a scrapes off foreign matter such as unnecessary toner and paper dust that has adhered to the surface of the photosensitive drum 61 during image formation.

[0056] Moreover, the collecting recess 800 is located on the front side of the sheet member 810 and below the leading end 810a of the sheet member 810 in the orthogonal direction (front-rear direction) perpendicular to the rotation axis direction of the photosensitive drum 61. The leading end 810a of the sheet member 810 abuts against the surface of the photosensitive drum 61 in a manner opposing the rotation direction of the photosensitive drum 61, so that foreign matter scraped off by the sheet member 810 falls into the collecting recess 800 and is collected.

[0057] In addition, since the collecting recess 800 is provided in the bridge portion 619 of the frame 610 of the drum unit 6, which is sandwiched between the end through-hole 68 and the sheet passing hole 618 and has reduced strength, it is possible to improve the strength of the frame 610. That is, the collecting recess 800 is provided adjacent to the electrode exposure hole 68a, the positioning hole 68b, and the sheet passing hole 618 at a position that overlaps with these holes 68a, 68b, and 618 in the direction perpendicular to the rotation axis direction of the photosensitive drum 61.

[0058] Therefore, the collecting recess 800 also functions as a rib that reinforces the bridge portion 619, improving the strength of the frame 610 at the bridge portion 619. In particular, as shown in Figure 17(b), the collecting recess 800 is configured such that its depth (the position of the upper surface of the bottom) D2 is deeper than the depth D1 of the positioning hole 68b (D2>D1), thereby enhancing the reinforcing effect. Therefore, the strength of the frame 610 around the positioning hole 68b is improved, which reduces distortion of the frame 610 and improves the positioning accuracy of the developing unit 7 in the left-right direction.

[0059] 2, the frame 610 of the drum unit 6 is also provided with a box-shaped collecting recess 830 similar to the collecting recess 800, and a sheet member 840 at the other end side in the rotational axis direction of the photosensitive drum 61 (the right side in this embodiment). This sheet member 840 stands upright from the frame 610 toward the photosensitive drum 61, and its tip is adapted to abut against the photosensitive drum 61. More specifically, the sheet member 840 abuts against the photosensitive drum 61 at an end portion that is axially outwardly spaced from the image forming area of ​​the photosensitive drum 61, and its tip scrapes off foreign matter such as unwanted toner and paper dust that has adhered to the surface of the photosensitive drum 61 during image formation.

[0060] Furthermore, since the collecting recess 830 is located on the front side of the sheet member 840 in a direction perpendicular to the rotational axis direction of the photosensitive drum 61, foreign matter scraped off by the sheet member 840 falls into the collecting recess 830 and is collected.

[0061] [Summary of the first embodiment] As described above, the cartridge (5) is detachably mountable to the main body (2) of the image forming apparatus (1), a drum unit (6) having a photosensitive drum (61) and a frame (610) that rotatably supports the photosensitive drum (61); a developing unit (7) that is detachably attached to the drum unit (6), the developing unit (7) including a developing roller (71) that supplies toner to the photosensitive drum (61) and a memory (85) that stores information; The drum unit (6) has a cleaning member (810) that comes into contact with an end of the photosensitive drum (61) in the direction of the rotation axis to clean the photosensitive drum (61), the frame (610) has an exposure hole (68a) for exposing the memory (85) from the frame (610), and a recess (800) adjacent to the exposure hole (68a) in the direction of the rotation axis of the photosensitive drum (61); The recess (800) is arranged so that at least a portion thereof overlaps with the cleaning member (810) in the direction of the rotation axis when viewed from a direction perpendicular to the direction of the rotation axis, and is recessed in a direction away from the cleaning member (810).

[0062] As described above, the frame 610 of the drum unit 6 is provided with the recess 800 adjacent to the exposure hole 68a in the direction of the rotation axis of the photosensitive drum 61. Therefore, even if the exposure hole 68a is formed, the strength of the frame 610 of the drum unit 6 can be improved. Furthermore, the recess 800 is provided so that at least a portion thereof overlaps with the direction of the rotation axis when viewed from a direction perpendicular to the rotation axis of the cleaning member 810 and the photosensitive drum 61. Therefore, the recess 800 can collect foreign matter such as excess toner and paper dust scraped off by the cleaning member 810.

[0063] Also, The developing unit (7) has a protrusion (86) extending toward the drum unit (6), the frame (610) has a positioning hole (68b) that engages with the protrusion (86) so as to determine the position of the developing unit (7) relative to the drum unit (6) in the direction of the rotation axis, The recess (800) is adjacent to the positioning hole (68b) in the direction of the rotation axis. In this way, since the recess 800 is disposed adjacent to the positioning hole 68b in the direction of the rotation axis, the strength of the frame 610 around the positioning hole 68b can be increased. This prevents the frame from being distorted around the positioning hole 68b, allowing the development unit 7 to be positioned with respect to the drum unit 6 with high precision.

[0064] The positioning hole (68b) is located between the exposure hole (68a) and the photosensitive drum (61) in the direction perpendicular to the rotation axis direction and communicates with the exposure hole (68a). As a result, the exposure hole 68a is disposed close to the positioning hole 68b, and the exposure hole 68b and the mark 85 can be positioned with high precision.

[0065] As described above, in this embodiment, the process cartridge (5) a drum unit (6) having a photosensitive drum (61); a developing unit (7) that is detachably attached to the drum unit (6) and that includes a developing roller (71) that supplies toner to the photosensitive drum (61) to develop a toner image, The developing unit (7) a memory (85) for storing information about the developing unit (7); a positioning protrusion (86) for determining the position of the developing unit (7) relative to the drum unit (6) in the direction of the rotation axis of the photosensitive drum (61); The drum unit (6) includes a frame (610) having a positioning hole (68b) and a recess (800) with which the positioning protrusion (86) engages, at one end side of the rotation axis line of the photosensitive drum (61), When viewed from the direction of the rotation axis of the photosensitive drum (61), the recess (800) is disposed at a position overlapping the positioning hole (68b) in a direction perpendicular to the direction of the rotation axis.

[0066] In this way, when viewed from the rotational axis direction of the photosensitive drum 61, if the recess 800 is disposed at a position overlapping with the positioning hole 68b in the direction perpendicular to the rotational axis direction, the strength of the area around the positioning hole 68b of the drum unit 6 is increased. This improves the accuracy of positioning the developing unit 7 and the drum unit 6 in the left-right direction using the positioning protrusion 86 and the positioning hole 68b. As a result, the memory electrode 85a of the developing unit 7 can be brought into contact with the electrode on the apparatus main body 2 side with high accuracy.

[0067] Furthermore, the depth (D2) of the recess (800) is configured to be deeper than the depth (D1) of the positioning hole (68b) (D2>D1), thereby enhancing the reinforcing effect of the frame 610 provided by the recess (800).

[0068] The drum unit (6) also includes a cleaning member (810) whose tip (810a) contacts the photosensitive drum (61), The recess (800) is disposed at a position overlapping the cleaning member (810) in the direction of the rotation axis of the photosensitive drum (61) when viewed from a direction perpendicular to the rotation axis. Therefore, the recess 800 can capture excess toner scraped off the surface of the photosensitive drum 61 by the cleaning member 810, foreign matter such as paper dust, and prevent it from scattering. As a result, it is possible to prevent contamination of the process cartridge 5 by foreign matter and image defects caused by foreign matter falling onto the sheet S. Additionally, by using the recess 800 both to reinforce the frame 610 of the drum unit 6 and to capture foreign matter, it is no longer necessary to provide a foreign matter capture component separate from the recess 800, which allows the cartridge to be made smaller and its configuration to be simplified.

[0069] Furthermore, the frame (610) of the drum unit (6) has an electrode exposure hole (68a) that exposes the electrode (85a) of the memory (85), The positioning hole (68b) is located downstream of the electrode exposure hole (68a) in the mounting direction of the developing unit (7) to the drum unit (6), and is formed to communicate with the positioning hole (68b). Therefore, when mounting the developing unit 7 to the drum unit 6, the positioning protrusion 86 can be guided into the positioning hole 68b via the electrode exposure hole 68a. Furthermore, because the electrode exposure hole 68a is located close to the positioning hole 68b, the memory electrode 85a can be positioned with high precision.

[0070] <Second embodiment> Next, the configuration of the process cartridge 5 according to the second embodiment will be described with reference to Figures 18 to 24. In the following description, only the parts that are different from those in the first embodiment will be described, and the other parts will be given the same names / reference numerals and will not be described again.

[0071] 18 to 20 show the state in which the developing unit 7 is attached to the drum unit 6. In this attached state, as described above, the developing unit 7 is positioned in the front-to-rear direction relative to the drum unit 6 by the bearings 746A and 746B engaging with the receiving portions (grooves) 641 of the drum unit 6A. That is, in this state, the bearings 746A and 746B serve as positioned protrusions that serve as positioned portions, and these bearings 746A and 746B are located on the rear side of the developing unit 7.

[0072] The developing unit 7 is positioned in the longitudinal direction (axial direction of the photosensitive drum 61) by a positioning protrusion 86 engaging with a positioning hole 68b of the drum unit 6, and the positioning protrusion 86 is also provided on the rear side of the developing unit 7. In addition, a memory 85 for recording information about the developing unit 7 is provided on the rear side of the developing unit 7.

[0073] In this way, the developing unit 7 has positioning portions 746A, 746B, and 86, which determine the relative position of the developing unit 7 with respect to the drum unit 6, disposed on the rear side near the photosensitive drum 61. This improves the positioning accuracy of the developing roller 71 with respect to the photosensitive drum 61. Furthermore, the developing unit 7 has the memory 85 disposed near these positioning portions 746A, 746B, and 86, thereby improving the positioning accuracy of the memory 85 with respect to the drum unit 6 and the apparatus main body 2.

[0074] The developing unit 7 is positioned relative to the drum unit 6 and is pressed toward the photosensitive drum 61 by the pressing members 640L and 640R so that the developing unit 7 is positioned relative to the drum unit 6 and the developing roller 71 is firmly in contact with the photosensitive drum 61. More specifically, the developing unit 7 has pressed portions 716, 716 at both longitudinal ends of its front end, and these pressed portions 716, 716 are pressed by the corresponding pressing members 640L and 640R. As the pressing members 640L and 640R press the developing unit 7, a pressing force from the pressing members 640L and 640R is applied to the rear side of the frame 610 of the drum unit 6 via the photosensitive drum 61 and bearings 746A and 746B. A reaction force to the pressing force acts on the front end wall 613 of the frame 610 via the biasing springs 644. Therefore, tension is generated in the front-rear direction on the bottom 614 of the frame 610 due to the above-mentioned pressing force and reaction force.

[0075] 21, however, a positioning hole 68b and an electrode exposure hole 68a, which is a through-hole for exposing the electrode 85a of the memory 85, are provided on the rear side of the bottom 614. In addition, a sheet passing hole 618 for supplying a sheet to the transfer nip N1 between the photosensitive drum 61 and the developing roller 71 overlaps with the positioning hole 68b and the electrode exposure hole 68a in a direction perpendicular to the rotation axis direction when viewed from the rotation axis direction of the photosensitive drum 61.

[0076] When such holes 68a, 68b, and 610b are formed, the strength of the frame 610 of the drum unit 6 is reduced. However, if the frame 610 is deformed by the tension described above, the pressing force may decrease, causing the contact state between the developing roller 71 and the photosensitive drum 61 to become unstable. A configuration for suppressing deformation of the frame 610 of the drum unit 6 will be described below.

[0077] 22, the frame 610 of the drum unit 6 is provided with a collecting recess 800 in a bridge portion 619 between the electrode exposure hole 68a and the positioning hole 68b and the sheet passing hole 618, thereby reinforcing the strength of the bridge portion 619. In the present embodiment, a reinforcing recess 820 is provided in the bridge portion 619 in addition to the collecting recess 800.

[0078] More specifically, this reinforcing recess (hereinafter referred to as reinforcing recess) 820 is a box-shaped recess that is recessed downward, and has a bottom surface (first wall surface) 821 that extends in the front-to-rear and left-to-right directions. It also has left and right wall surfaces (second and second wall surfaces) 822, 823 that stand upright from the bottom surface 821 to face each other and spaced apart in the left-to-right direction, and front and rear wall surfaces (fourth and fifth wall surfaces) 824, 825 that stand upright from the bottom surface 821 to face each other and spaced apart in the front-to-rear direction.

[0079] The reinforcing recess 820 is provided at a predetermined distance in front of the collecting recess 800. More specifically, as shown in Fig. 23 , the reinforcing recess 820 is disposed so as to overlap with the electrode exposure hole 68a and the sheet passing hole 618 in the front-rear direction perpendicular to the rotation axis direction when viewed from the rotation axis direction of the photosensitive drum 61. That is, in the front-rear direction, the range X1 in which the sheet passing hole 618 is formed includes the range X2 in which the end through-hole 68 is formed. Furthermore, at least a portion of the ranges X1 and X2 in which the collecting recess 800 and the reinforcing recess 820 are formed overlap with each other.

[0080] The tension applied to the frame 610 described above increases at positions overlapping with the pressing members 640L and 640R in the rotational axis direction of the photosensitive drum 61. In this embodiment, as shown in FIG. 24, the pressing member 640L is disposed inward of the electrode exposure hole 68a in the rotational axis direction when viewed from a direction perpendicular to the rotational axis direction. The pressing member 640L is also disposed at a position overlapping with the bridge portion 619 in the direction perpendicular to the rotational axis direction when viewed from the rotational axis direction. That is, the pressing range Y1 of the pressing member 640L in the left-right direction (rotational axis direction) does not overlap with the left-right formation range Y3 of the end through-hole 68, and the pressing range Y1 partially overlaps with the left-right formation range Y2 of the bridge portion 619. Furthermore, the pressing range Y1 partially overlaps with the sheet passing hole 618 in a direction perpendicular to the rotation axis direction when viewed from the rotation axis direction.

[0081] As described above, in this embodiment, in the direction perpendicular to the rotation axis direction when viewed from the rotation axis direction, pressing member 640 is disposed in a range that does not overlap with electrode exposure hole 68a but overlaps with bridging portion 619. This allows the tension to be received at the position where bridging portion 619, which is reinforced by providing reinforcing recess 820 and collecting recess 800, is located.

[0082] [Summary of the second embodiment] The process cartridge (5) according to this embodiment includes: a drum unit (6) having a photosensitive drum (61); a developing unit (7) that is detachably attached to the drum unit (6) and that includes a developing roller (71) that supplies toner to the photosensitive drum (61) to develop a toner image, The developing unit (7) a memory (85) for storing information about the developing unit (7); a positioning protrusion (86) for determining the position of the developing unit (7) relative to the drum unit (6) in the direction of the rotation axis of the photosensitive drum (61); The drum unit (6) is a pressing member (640L) that presses the developing unit (7) toward the photosensitive drum (61); a frame (610) having, at one end side of the rotation axis direction of the photosensitive drum (61), a positioning hole (68b) with which the positioning protrusion (86) engages and an electrode exposure hole (68a) through which an electrode (85a) of the memory (85) is exposed; The electrode exposure hole (68a) is located outside the pressing member (640L) in the direction of the rotation axis of the photosensitive drum (61) when viewed from a direction perpendicular to the direction of the rotation axis.

[0083] In this way, the electrode exposure hole 68a exposing the memory electrode 85a is disposed outside the pressing member 640 in the direction of the rotation axis of the photosensitive drum 61. This prevents deformation of the frame 610 of the drum unit 6 due to the pressing force of the pressing member 640, and allows the developing roller 71 of the developing unit 7 to be stably pressed toward the photosensitive drum 61. This allows the developing roller 71 to stably abut against the photosensitive drum 61, preventing the occurrence of image defects. Furthermore, by locating the electrode exposure hole 68a near the positioning portion of the developing unit 7, the positioning accuracy of the memory 85 relative to the drum unit 6 and the main body 2 of the device can be improved. In addition, the improved positioning accuracy of the memory 85 can improve the stability of information communication with the control unit of the main body 2 of the device.

[0084] In particular, the frame (610) of the drum unit (6) has a sheet passing hole (610b) through which a sheet passes toward the photosensitive drum (61), and a bridge portion (619) located between the exposure hole (68a) and the sheet passing hole (618) in the rotation axis direction, The pressing member (640L) is disposed at a position overlapping the bridge portion (619) in the rotational axis direction of the photosensitive drum (61) when viewed from a direction perpendicular to the rotational axis direction. Therefore, the tension generated in the frame 610 of the drum unit 6 can be received by the bridge portion 619, and deformation of the frame 610 can be effectively suppressed.

[0085] In addition, a recess (820) is formed in the bridge portion (619). By providing the reinforcing recess 820 in this manner, the strength of the bridge portion 619, on which the tension acts, is improved, and the strength of the frame 610 of the drum unit 6 can be improved.

[0086] <Third embodiment> Next, the configuration of the process cartridge 5 according to the third embodiment will be described with reference to Figures 25 to 27. In the following description, only the parts that are different from those in the first embodiment will be described, and the other parts will be given the same names / reference numerals and will not be described again.

[0087] Figure 25 is a diagram showing the structure around the memory 85 of the process cartridge 5 when the developing unit 7 is attached to the drum unit 6. As shown in Figure 26, in this embodiment, the positioning protrusion 86a of the developing unit 7 has a stepped tip, and the upstream end in the attachment direction of the process cartridge 5 forms a protruding portion 861 that protrudes downward by a large amount. In addition, on the downstream side of this protruding portion 861 in the attachment direction of the process cartridge 5, a gap holding portion 862 that protrudes by a smaller amount than the above-mentioned protruding portion 861 is formed.

[0088] Furthermore, rough guides 497, 497 are formed on the bottom surface of the process cartridge 5 (drum unit 6) upstream of the positioning protrusion 86 in the mounting direction of the process cartridge 5. The rough guides 497, 497 are formed by a pair of plate-like guide members arranged at a predetermined interval in the rotational axis direction of the photosensitive drum 61, and these opposing guide members extend parallel to the mounting direction.

[0089] 26(a) and 26(b), the electrode unit 490 on the device body 2 side of the printer 1, which the electrode 85a of the memory 85 of the developing unit 7 abuts against, has an electrode substrate 492 as an electrode portion housed in an electrode holder 493. A predetermined clearance is provided between the electrode holder 493 and the electrode substrate 492, and the electrode substrate 492 is supported by an elastic body 494. This elastic body 494 is formed of a porous elastic body such as urethane foam or a metal spring, and the device body 2 side electrode 491 provided on the electrode substrate 492 is supported by a floating structure that allows it to move in the front-to-back and left-to-right directions within the clearance. The device body side electrode 491 is connected to a cable 496 that connects to a control unit (not shown) in the image forming apparatus 1, so that electrical continuity to the control unit is maintained even if the electrode substrate 492 moves slightly.

[0090] The electrode substrate 492 is also provided with a guide groove 495 that engages with the protruding portion 861 of the positioning projection 86a of the developing unit 7. That is, in this embodiment, the protruding portion 861 serves as an engaging portion that engages with the guide groove 495, which serves as an engaged portion. As shown in FIG. 27A, when the process cartridge 5 is mounted in the main body 2 of the printer 1, the process cartridge 5 is positioned so that the electrode holder 493 is sandwiched between the rough guides 497, and then moved in the mounting direction (the direction of the arrow in the figure). Guided by the rough guides 497, the process cartridge 5 moves with the protruding portion 861 of the positioning projection 86a maintained at a slight distance from the main body electrode 491. Then, as shown in FIG. 27B, the process cartridge 5 moves downward just before reaching the mounting position, and the protruding portion 861 of the positioning projection 86a is inserted into the guide groove 495 of the electrode substrate 492.

[0091] At this time, even if the attitude of the process cartridge 5 is slightly twisted back and forth or left and right with respect to the correct installation position in the device body 2 of the printer 1, the electrode substrate 492 changes its attitude so as to follow the process cartridge 5 via the protrusion 861 and the guide groove 495. Then, in this changed state, the device body side electrode 491 and the memory electrode 85a come into contact, and the process cartridge 5 is further pushed into the correct installation position, completing the installation.

[0092] The distance between the main body electrode 491 and the memory electrode 85a is maintained at an appropriate distance by the gap maintaining portion 862 of the positioning protrusion 86a directly contacting the electrode substrate 492 and pressing the electrode substrate 492 downward. The distance between the main body electrode 491 and the memory electrode 85a is also maintained at an appropriate distance by the gap maintaining portion 862. This prevents the main body electrode from being crushed when the process cartridge 5 is installed, and also maintains an appropriate pressure on the main body electrode.

[0093] Furthermore, when the process cartridge 5 is pushed into the installation position, the process cartridge 5 moves to eliminate its twist, and the electrode substrate 492 changes its position in conjunction with the process cartridge 5. This prevents the main body electrode 491 and the memory electrode 85a from moving relative to each other, reducing stress on the main body electrode 491.

[0094] [Summary of the third embodiment] The process cartridge (5) according to this embodiment is a process cartridge (5) that is detachably mountable to the image forming apparatus (1), a drum unit (6) having a photosensitive drum (61); a developing unit (7) that is detachably attached to the drum unit (6) and that includes a developing roller (71) that supplies toner to the photosensitive drum (61) to develop a toner image, The developing unit (7) a memory (85) for storing information about the developing unit (7); a positioning protrusion (86a) for determining the position of the developing unit (7) relative to the drum unit (6) in the direction of the rotation axis of the photosensitive drum (61); an electrode (85a) of the memory (85) abuts against an electrode (491) provided on the main body side of the image forming apparatus (1), and an electrode portion (492) provided with the electrode (491) on the main body side of the image forming apparatus (1) is held by a floating structure in which the position of the electrode (491) is movable; The positioning projection (86a) of the developing unit (7) has an engaging portion (861) that engages with the electrode portion (492).

[0095] In this way, when the electrode portion 492 has a floating configuration that changes its position in conjunction with the process cartridge 5, the memory electrode 85a can be reliably brought into contact with the main body electrode 491. This makes it possible to reduce the size of the memory 85 (or its memory electrode 85a). Furthermore, in this embodiment, the positioning protrusion 86a that engages the developing unit 7 and the drum unit 6 also serves as a positioning member for the floating electrode portion 492 of the image forming apparatus 1. This ensures a more stable electrical conduction environment for the process cartridge 5 and prevents damage to the electrodes.

[0096] The positioning projection 86a also includes a gap maintaining portion 862 that abuts against the electrode portion 492 to maintain a predetermined distance between the electrode 85a of the memory 85 and the electrode 491 on the device body side. By maintaining the spacing between the electrodes with the gap maintaining portion 862, the electrodes can be protected and the contact pressure between the electrodes can be maintained at an appropriate level.

[0097] The developing unit (7) is provided with a rough guide (497) that interferes with an electrode holder (493) that houses the electrode portion (492) and guides the engaging portion (861) of the positioning protrusion (86a) to the electrode portion (492). This makes it possible to easily and quickly guide the engaging portion 861 of the positioning protrusion 86a to the electrode portion 492.

[0098] In the present embodiment, an example has been described in which the developing unit 7 is provided with the positioning protrusion 86a and the electrode portion 492 is provided with the guide groove 495. However, this is not limiting, and even if the developing unit 7 is provided with the guide groove and the electrode portion 492 is provided with the positioning protrusion, the memory electrode 85a can be accurately positioned to abut against the device body side electrode 491.

[0099] <Fourth embodiment> Next, the configuration of the process cartridge 5 according to the fourth embodiment will be described with reference to Figures 28 to 31. In the following description, only the parts that are different from those in the first embodiment will be described, and the other parts will be given the same names / reference numerals and will not be described again.

[0100] 28(a) and 28(b), an opening 6141 is provided in the front bottom portion 614Fa on the front side of the bottom portion 614a of the frame 610a of the drum unit 6. The bottom surface of the housing 700a of the developing unit 7 fits into this opening 6141, as shown in FIGS.

[0101] 29(a) to 30(b), because the opening 6141 is formed in the frame 610a of the drum unit 6, the housing 700a of the developing unit 7 is configured to increase the volume of the toner storage section 74. That is, the housing 700a has a bottom 700a1 that forms the front storage portion of the toner storage section 74 where the second agitator 75B is provided, and protrudes downward significantly.

[0102] Therefore, as shown in FIG. 30(b), when the bottom portion 700a1 is inserted into the opening 6141, a lower end portion 700a11 of the lower surface (bottom surface) of the bottom portion 700a1 is located lower than the upper surface 614Fa1 of the front bottom portion 614Fa.

[0103] Furthermore, in order to increase the downward protrusion amount of the bottom portion 700a1, in this embodiment, the protrusions 643a, 643a formed on the upper surface 614Fa1 of the front bottom portion 614Fa are provided further forward than the opening 6141. In addition, the ribs 718a of the developing unit 7 supported by the protrusions 643a, 643a are also provided further forward than the lower end portion 700a11.

[0104] Furthermore, in this embodiment, as shown in FIGS. 30(a) and 30(b), a conveying roller (conveying member) 521 is attached to the frame 610a of the drum unit 6 on the underside 614Fa2 of the front bottom portion 614Fa. More specifically, this conveying roller 521 is located rearward of the opening 6141, and as shown in FIG. 31, when the process cartridge 5 is attached to the apparatus main body 2, it serves as the conveying roller on one side (the upper side in this embodiment) of the pair of conveying rollers 520. Note that this pair of conveying rollers 520 is a pair of conveying rollers disposed on the sheet conveying path between the cassette 31 and the transfer nip N1. In addition, retaining caps are attached to both ends of the conveying roller 521 to prevent it from coming off the frame 610a.

[0105] [Summary of the Fourth Embodiment] The process cartridge (5) of this embodiment includes: a developing unit (7) having a developing roller (71); a drum unit (6) including a photosensitive drum (61) on whose surface a toner image is developed by the developing roller (71) and a frame (610a) to which the developing unit (7) is detachably mounted; The frame (610a) has a bottom (614Fa) that supports the developing unit (7), and an opening (6041) is formed in which a part of the developing unit (7) fits in when the developing unit (7) is attached, and a part (700a11) of the developing unit (7) is located below the surface (614Fa1) of the bottom (614Fa) that faces the developing unit (7) when viewed from the direction of the rotation axis of the photosensitive drum (61).

[0106] This allows the bottom 700a1 of the developing unit 7 to be enlarged to accommodate more toner, thereby providing a developing unit 7 with a large toner storage capacity.

[0107] The drum unit (6) also includes a roller (521) that is rotatably supported on the opposite side of the bottom (614Fa) of the frame (610a) from the developing unit (7). The bottom 700a1 of the developing unit 7 is located forward of the roller 521, which serves as a transport member, and therefore does not affect paper passage in the device body 2 even if it protrudes downward from the opening 6041 of the drum unit 6. Furthermore, by providing the transport member 521 in the drum unit 6, the device body 2 can be made more compact.

[0108] <Fifth embodiment> Next, the configuration of the process cartridge 5 according to the fifth embodiment will be described with reference to Figures 32(a) to 34(b). Note that in the following description, only the parts that are different from the fourth embodiment will be described, and the other parts will be given the same names / reference numerals and will not be described again.

[0109] 32(a) to 34(b), in the present embodiment, frame 610b of drum unit 6 is formed with an opening 6142, into which bottom 700b1 of housing 700b of developing unit 7 fits, expanded to front end wall 613a. More specifically, opening 6142 is composed of fitting portion 6142a into which bottom 700b1 of developing unit 7 fits, and opening portion 6142b that opens fitting portion 6142a to the front side.

[0110] The open portion 6142b is formed slightly narrower than the fitting portion 6142a in the rotational axis direction of the photosensitive drum 61 and extends forward from the fitting portion 6142a. Therefore, on the front side of the fitting portion 6142a, the front bottom portion 614Fb and the front end wall 613a have central portions cut out in a way that opens the fitting portion 6142a. Note that pressing members 640, 640 and protrusions 643a, 643a are formed on the left and right front bottom portions 614Fb and front end wall 613a that are not cut out by the open portion 6142b.

[0111] [Summary of the fifth embodiment] The process cartridge (5) of this embodiment includes: a developing unit (7) having a developing roller (71); a drum unit (6) including a photosensitive drum (61) on whose surface a toner image is developed by the developing roller (71) and a frame (610b) to which the developing unit (7) is detachably mounted; The frame (610b) has a bottom (614Fb) supporting the developing unit (7) that has an opening (6142) into which a part of the developing unit (7) fits when the developing unit (7) is attached, The opening (6242) is formed with an open end on the opposite side to the developing roller (61), A part (700b11) of the developing unit (7) is located below a surface (614Fb1) of the bottom (614Fb) facing the developing unit when viewed from the direction of the rotation axis of the photosensitive drum.

[0112] As described above, when viewed from a direction perpendicular to the axis of the photosensitive drum 61, the lower end 700b11 of the lower surface (bottom surface) 700b1 of the developing unit 7 protrudes downward from the upper surface 614Fb1 of the bottom portion 614Fb of the frame 610b of the drum unit 6. Furthermore, because the end of the opening 6242 opposite the photosensitive drum 61 is open, the front end of the housing 700 of the developing unit 7 can be expanded forward from the front end wall 613a. This allows for the provision of a developing unit 7 that can accommodate more toner and has a large capacity.

[0113] In this embodiment, the center of the front end wall 613a is cut out, and there is no gripping portion on the drum unit 6 side for the user to grip, but when the process cartridge 5 is attached to the apparatus main body 2, the gripping portion 701 of the developing unit 7 is gripped.

[0114] Sixth Embodiment Next, the configuration of the process cartridge 5 according to the sixth embodiment will be described with reference to Figures 35 to 43. In the following description, only the parts that are different from the fourth embodiment will be described, and the other parts will be given the same names / reference numerals and will not be described again.

[0115] As shown in Figures 35 and 36, in the process cartridge 5 of this embodiment, not only the developing unit 7 but also the drum unit 6 is provided with a memory 630 that stores information about the drum unit 6. Similarly, the apparatus main body 2 is also provided with a main body-side electrode 252 that abuts against an electrode 630a of this memory 630. In the following description, the memory 85 of the developing unit 7 will be referred to as the developing memory, and the memory 630 of the drum unit 6 will be referred to as the drum unit memory. Also, the apparatus main body-side electrode (electrical contact) 491 that abuts against the electrode (electrical contact) 85a of the developing memory 85 will be referred to as the first main body-side electrode, and the electrode (electrical contact) that abuts against the electrode (electrical contact) 630a of the drum unit memory 630 will be referred to as the second main body-side electrode 500.

[0116] The drum unit memory 630 stores information regarding replacement of the photosensitive drum 61 (for example, the cumulative number of rotations and cumulative time). The drum unit memory 630 is fixed to a rear end wall 620 erected at the rear end of the frame 610 of the drum unit 6 by means of adhesive bonding, welding, heat caulking, press-fitting, clamping, or the like. Therefore, the electrode 630a of the drum unit memory 630 is exposed facing rearward and comes into contact with the second main-body electrode 500 when the process cartridge 5 is attached to the apparatus main body 2. The electrode 630a of the drum unit memory 630 may also be exposed rearward through an opening formed in the rear end wall 620.

[0117] 36 to 39(b), the above-mentioned first photosensitive drum gear 65 (also see FIG. 14 of the first embodiment) that rotates the photosensitive drum 61 is exposed by opening a part of the rear end portion of the frame 610. This opening 6101 is adapted to mesh with the drive gear 510 on the apparatus main body 2 side.

[0118] Figure 40(a) is a perspective view of the inside of the apparatus main body 2 seen from right to left. The drive gear 510 is located at the rear left side in the installation space of the apparatus main body 2 for the process cartridge 5. A second main body electrode 500 is provided on the left side of the rear wall of the apparatus main body 2, and a first main body electrode 491 is provided on the lower left side.

[0119] Furthermore, a left-side main body guide 254 is provided on the left side wall of the apparatus main body 2, and this left-side main body guide 254 includes a first guide portion 254a, a second guide portion 254b, a main body side drive coupling 255, and a protrusion 254c. This first guide portion 254a guides a first positioning protrusion 660 provided on the left side wall 611 of the drum unit 6, and the second guide portion 254b guides a first guide rib 662 (see also Figure 40(b)). In addition, the main body side drive coupling 255 engages with and drives the development coupling 710.

[0120] As shown in Figure 41(a), a right-side main body guide 253 is also provided on the right side wall of the apparatus main body 2. This right-side main body guide 253 includes a third guide portion 253a and a fourth guide portion 253b. The third guide portion 253a guides the second positioning protrusion 661 provided on the right side wall 612 of the drum unit 6, and the fourth guide portion 253b guides the second guide rib 663 (see also Figure 41(b)).

[0121] Next, the relationship between the meshing of the drive gear 510 and the first photosensitive drum gear 65 and the contact of the electrodes will be described. As shown in Fig. 42, the first photosensitive drum gear 65 is exposed through an opening 6101 in the frame 610. When viewed from the rotational axis direction of the photosensitive drum 61, this opening 6101 overlaps with the electrode 85a of the development memory 85 and the electrode 630a of the drum unit memory 630 in a direction perpendicular to the rotational axis direction. The area indicated by the dimension W1 in the drawing is the range in which the opening 6101 exists in the rotational axis direction.

[0122] Here, the first photosensitive drum gear 65 is configured as a helical gear with a right-hand twist direction. Note that in this embodiment, a helical gear with a right-hand twist direction refers to a direction that rises to the right when viewed from the front with the rotation axis facing up and down. Similarly, the drive gear 510 on the device main body 2 side, with which the first photosensitive drum gear 65 meshes, is also formed as a corresponding helical gear. Then, when the first photosensitive drum gear 65 receives drive from this drive gear 510 and rotates in the direction of arrow R, which is the rotation direction of the photosensitive drum 61, a thrust force generated by the helical gear causes the first photosensitive drum gear 65 to receive a force that moves it in the direction of arrow XX.

[0123] Then, the end face 65c of the first photosensitive drum gear 65 abuts against the inner end face 610i of the frame 610 of the drum unit 6, whereby the first photosensitive drum gear 65 is positioned relative to the frame 610. Also, in this case, the frame 610 of the drum unit 6 is pressed in the direction of arrow XX by the end face 65c of the first photosensitive drum gear 65. Therefore, as a result, the contact surface 610g of the frame 610 of the drum unit 6 shown in FIG. 40(b) abuts against the convex portion 254c of FIG. 40(a). And thereby, the positions in the rotational axis direction (left - right direction) of the apparatus main body 2 and the process cartridge 5 are positioned.

[0124] Thus, when the position in the rotational axis direction of the process cartridge 5 is positioned with high precision, the electrode 85a of the developing memory 85 and the first main - body - side electrode 491, and the electrode 630a of the drum unit memory 630 and the second main - body - side electrode 500 are also positioned with high precision. Also, when the positioning accuracy in the rotational axis direction of each electrode is high in this way, as shown in FIG. 42, the widths in the rotational axis direction of the electrode 85a and the electrode 630a can be formed narrower. For example, in the present embodiment, when the width in the rotational axis direction is L1 and the width in the direction orthogonal to the rotational axis direction is L2, the electrode 85a and the electrode 630a are formed by a rectangle in which the relationship L1 < L2 holds. Since the electrode 85a and the electrode 630a are plated with a precious metal such as gold plating, the cost can be reduced by the amount that the width in the rotational axis direction can be narrowed.

[0125] [Summary of the Sixth Embodiment] The process cartridge (5) according to the present embodiment includes a drum unit (6) having a photosensitive drum (61), and a developing unit (7) configured to be detachable from the drum unit (6) and including a developing roller (71) that supplies toner to the photosensitive drum (61) to develop a toner image. [[ID=十六]]The developing unit (7) includes a first memory (85) that stores information of the developing unit (7), and the drum unit (6) a second memory (630) for storing information about the drum unit (6); a photosensitive drum gear (65) that meshes with a gear (510) on the device main body side to drive the photosensitive drum (61); The photosensitive drum gear (65) is a helical gear.

[0126] In this way, since the photosensitive drum gear 65 is configured by a helical gear, the thrust force received by this photosensitive drum gear 65 can accurately position the process cartridge 5 relative to the apparatus main body 2 in the direction of the rotation axis of the photosensitive drum 61. Therefore, the positioning of the first and second memories 85, 630 relative to the electrodes on the apparatus main body side can also be performed with high accuracy.

[0127] The photosensitive drum gear (65) is configured to receive a force from the gear (510) on the device main body side toward one side in the direction of the rotation axis of the photosensitive drum (61), The first and second memories (85, 630) are disposed on one side in the direction of the rotation axis of the photosensitive drum (61) of the process cartridge (5). By moving the first and second memories 85, 630 closer to the side of the process cartridge 5 where they are positioned, the first and second memories 85, 630 can be positioned with higher accuracy relative to the electrodes on the main body of the apparatus.

[0128] Seventh Embodiment Next, the configuration of the process cartridge 5 according to the seventh embodiment will be described with reference to Figures 44(a) to 45. In the following description, only the parts that are different from the sixth embodiment will be described, and the other parts will be given the same names / reference numerals and will not be described again.

[0129] In the first to sixth embodiments described above, a configuration has been described in which the cleaning blade 64 is in contact with the photosensitive drum 61. In this embodiment, a process cartridge 5 that does not use a cleaning blade as a cleaning member will be described. As shown in Figures 44(a) and 44(b), in the drum unit 6, a paper dust removing roller 690 is in contact with the photosensitive drum 61 upstream of the charging roller 62 and downstream of the transfer roller 63. In addition, a roller cleaner 691 is in contact with this paper dust removing roller 690.

[0130] The charging roller 62 is rotatably supported by a bearing 62a, and this bearing 62a is urged by a spring 62b toward the photosensitive drum 61. In addition, the paper dust removing roller 690 and the roller cleaner 691 are rotatably supported by a bearing 693. The bearing 693 is urged toward the photosensitive drum 61 by a spring 694.

[0131] 45 is an exploded perspective view showing the drive train of the paper dust removing roller 690, roller cleaner 691, and transfer roller 63. The drive train is composed of a transmission gear 900 that meshes with the first photosensitive drum gear 65, a roller cleaner outer gear 901, an intermediate body 902, a roller cleaner inner gear 903, and a paper dust removing roller gear 904, connected in this order. The roller cleaner outer gear 901 is attached to the end of the metal shaft of the roller cleaner 691 so as not to rotate relative to it. The paper dust removing roller gear 904 is attached to the end of the metal shaft of the paper dust removing roller 690 so as not to rotate relative to it. The roller cleaner outer gear 901, intermediate body 902, and roller cleaner inner gear 903 form an Oldham coupling. As a result, the drive connection state is maintained even when the paper dust removing roller 690 and roller cleaner 691 move relative to the frame 610.

[0132] As described above, the second photosensitive drum gear 66 is provided on the inside of the first photosensitive drum gear 65 in the direction of the rotation axis, and the driving force of the first photosensitive drum gear 65 is transmitted to the second photosensitive drum gear 66. A transfer gear 67 is provided on the end of the transfer roller 63, and this transfer gear 67 is engaged with the second photosensitive drum gear 66 and is driven to rotate.

[0133] The first photosensitive drum gear 65 and the second photosensitive drum gear 66 may be either integral or separate. If they are separate, the first photosensitive drum gear 65 and the second photosensitive drum gear 66 are configured so that the driving force is transmitted between them by engaging the recesses and projections.

[0134] [Summary of the Seventh Embodiment] In the drum unit 6 of this embodiment, the components that act as brakes against the rotation of the photosensitive drum 61 are the paper dust removal roller 690, the roller cleaner 691, the charging roller 62, and the transfer roller 63. The greater the braking force against the rotation of the photosensitive drum 61, the greater the thrust force of the first photosensitive drum gear 65, which is a helical gear. This makes it easier for the process cartridge 5 to move in the direction of the rotation axis of the photosensitive drum 61, and more reliably positions the process cartridge 5 and the photosensitive drum 61 of the apparatus main body 2 in the direction of the rotation axis.

[0135] In this embodiment, the paper dust removing roller 690, the charging roller 62, and the transfer roller 63 are contact members that come into contact with the photosensitive drum. In addition to these, a cleaning blade may be further provided as a contact member. The contact member may be of a form other than that described above, as long as it acts as a brake against the rotation of the photosensitive drum 61.

[0136] <Eighth embodiment> Next, the configuration of the process cartridge 5 according to the eighth embodiment will be described with reference to Figures 46(a) and 46(b). Note that in the following description, only the parts that are different from the sixth embodiment will be described, and the other parts will be given the same names / reference numerals and will not be described again.

[0137] As shown in Figures 46(a) and 46(b), in this embodiment, the drum unit memory 6301 is provided on the upper surface 610U of a cover portion that covers the photosensitive drum 61 at the rear side of the frame 610 of the drum unit 6. More specifically, the drum unit memory 6301 is arranged in the following order from the rear side in the front-to-rear direction: the drum unit memory 6301, the first positioning protrusion 660, the abutment surface 610g, and the developing memory 85. In addition, the second body-side electrode 500a on the apparatus main body 2 is also provided to protrude downward in correspondence with the drum unit memory 6301. Therefore, the direction in which the electrode 6301a of the drum unit memory 6301 is pressed by the second body-side electrode 500a is substantially perpendicular to the mounting direction S1 of the process cartridge 5.

[0138] [Summary of the Eighth Embodiment] As described above, in this embodiment, the direction in which the electrode 6301a of the drum unit memory 6301 is pressed by the second body-side electrode 500a is set to a direction that intersects with the mounting direction S1. This reduces the force that the process cartridge 5 receives from the second body-side electrode 500a in the direction in which it is removed from the apparatus main body 2. This reduces factors that deteriorate the positioning accuracy of the process cartridge 5 within the apparatus main body 2, thereby improving the positioning accuracy of the process cartridge 5 relative to the apparatus main body 2.

[0139] <Ninth embodiment> Next, the configuration of the process cartridge 5 according to the ninth embodiment will be described with reference to Figures 47(a) and 47(b). Note that in the following description, only the parts that are different from the eighth embodiment will be described, and the other parts will be denoted by the same reference numerals and will not be described again.

[0140] As shown in Figures 47(a) and 47(b), in this embodiment, a drum unit memory 6302 that stores information about the drum unit 6 is provided on the lower left rear side of the frame 610 of the drum unit 6. That is, the drum unit memory 6302 is attached to the underside of the front bottom portion 614F of the frame 610, and its electrode 6302a is exposed downward. That is, the drum unit memory 6302 is disposed on the underside (abutment surface) of the first guide rib 662 supported by the second guide portion 254b. Correspondingly, the second main body electrode 500b on the device main body 2 side also protrudes upward from the device main body 2.

[0141] [Summary of the ninth embodiment] As described above, in this embodiment, the direction in which the electrode 6302a of the drum unit memory 6302 is pressed by the second main body electrode 500b is set to a direction that intersects with the mounting direction S1. Therefore, this pressing force reduces the force that the process cartridge 5 receives in the direction in which it is removed from the main body 2 of the apparatus. Therefore, it is possible to reduce factors that deteriorate the positioning accuracy of the process cartridge 5 within the main body 2 of the apparatus, and to improve the positioning accuracy of the process cartridge 5 relative to the main body 2 of the apparatus.

[0142] Furthermore, by arranging the drum unit memory 6302 on the abutment surface side of the first guide rib 662, it is possible to prevent the drum unit memory 6302 from getting too close to the second body side electrode 500b. This stabilizes the vertical position of the drum unit memory 6302 and reduces variations in the electrode contact pressure.

[0143] <Tenth embodiment> Next, the configuration of the process cartridge 5 according to the tenth embodiment will be described with reference to Figures 48(a) to 53(b). Note that in the following description, only the parts that are different from the eighth embodiment will be described, and the other parts will be given the same names / reference numerals and will not be described again.

[0144] As shown in Figures 48(a) and 48(b), in this embodiment, a drum unit memory 6303 that stores information about the drum unit 6 is provided on the front end wall 613 of the frame 610 of the drum unit 6. Therefore, the electrode 6303a of the drum unit memory 6303 protrudes forward and is exposed.

[0145] Correspondingly, as shown in Fig. 49(a), the second body-side electrode 500c on the apparatus main body 2 side is attached to the inner wall of the main body door 21a, which serves as an opening / closing member. The main body door 21a is configured to be rotatable around a rotation shaft 21c as the center of rotation, and when the main body door 21a is in the open state as shown in Fig. 49(a), the second body-side electrode 500c and the electrode 6303a of the drum unit memory 6303 are spaced apart. When the main body door 21a is in the closed state as shown in Fig. 49(b), the second body-side electrode 500c comes into contact with the electrode 6303a of the drum unit memory 6303.

[0146] In the closed state, the second main body electrode 500c biases the process cartridge 5 in a direction pushing it rearward due to the contact pressure of the electrode. As a result, the first positioning protrusion 660 is pressed in a direction contacting the rear side surface of the first guide portion 254a, and the relative position of the process cartridge 5 with respect to the apparatus main body 2 can be stabilized.

[0147] 50(a) and 50(b), the developing memory 851 is arranged as follows. That is, in this embodiment, the sheet passing hole 618 has an entrance portion that is widened so as to guide the sheet into the sheet passing hole 618. More specifically, this entrance portion has an edge portion 618a (indicated by a two-dot chain line) that is narrow in the front-rear direction, and an edge portion 618b (indicated by a two-dot chain line) that is wide in the front-rear direction. The developing memory 851 is arranged so that a part of the positioning hole 68b1 and the electrode exposure hole 68a are located forward of the edge portion 618a in the front-rear direction.

[0148] By doing so, when viewed from the rotation axis direction of the photosensitive drum 61, the positioning hole 68b1 and the electrode exposing hole 68a1 can be shifted forward from the sheet passing hole 618 in a direction perpendicular to the rotation axis direction. This allows the positioning hole 68b1 and the electrode exposing hole 68a1 to be spaced apart from the sheet passing hole 618, thereby improving the strength of the frame 610 of the drum unit 6.

[0149] 51(a) and 51(b), the positioning hole 68b2 and the electrode exposure hole 68a2 may be separate holes, and these positioning hole 68b2 and electrode exposure hole 68a2 may be arranged side by side in the direction of the rotation axis of the photosensitive drum 61. In this case as well, by arranging the positioning hole 68b2 and the electrode exposure hole 68a2 to be shifted forward from the edge portion 618a, the distance between the positioning hole 68b2 and the electrode exposure hole 68a2 and the sheet passing hole 618 can be increased.

[0150] Furthermore, by forming the positioning hole 68b2 and the electrode exposure hole 68a2 as independent holes, a partition (bridge) 6191 that connects the front and rear edges of the holes is formed between the positioning hole 68b2 and the electrode exposure hole 68a2. This reduces the area of ​​each opening, thereby improving the strength of the frame 610 of the drum unit 6.

[0151] 52(a) and 52(b), the positioning hole 68b3 and the electrode exposure hole 68a3 may be formed separately, with the positioning hole 68b3 located on the front side of the edge 618a and the electrode exposure hole 68a3 located on the rear side of the edge 618a in the front-to-rear direction. In this case, the positioning hole 68b3 and the electrode exposure hole 68a3 are arranged so as not to overlap in the rotational axis direction when viewed from a direction perpendicular to the rotational axis direction of the photosensitive drum 61. That is, the positioning hole 68b3 and the electrode exposure hole 68a3 are separated by the partition 6192, which reduces the area of ​​each opening and improves the strength of the frame 610 of the drum unit 6.

[0152] 53(a) and 53(b), the positioning hole 68b3 and the electrode exposure hole 68a3 may be formed separately. The positioning hole 68b3, the electrode exposure hole 68a3, and the sheet passing hole 618 may be arranged to overlap in the rotation axis direction when viewed from a direction perpendicular to the rotation axis direction of the photosensitive drum. Even in this case, the positioning hole 68b3 and the electrode exposure hole 68a3 are separated by the partition 6193, which reduces the area of ​​each opening and improves the strength of the frame 610 of the drum unit 6.

[0153] [Summary of the Tenth Embodiment] In this way, by providing the drum unit memory 6303 on the front end wall 613 of the frame 610, the second main body electrode 500c can be biased in a direction that pushes the process cartridge 5 rearward by the contact pressure of the electrode. This stabilizes the relative position of the process cartridge 5 with respect to the apparatus main body 2. As a result, the accuracy of alignment between the electrodes of the drum unit memory 6303 and the developing memory 851 and the electrodes on the apparatus main body side is improved.

[0154] <Eleventh embodiment> Next, the configuration of the process cartridge 5 according to the eleventh embodiment will be described with reference to Figures 54 and 55. In the following description, only the parts that are different from the first embodiment will be described, and the other parts will be given the same names / reference numerals and will not be described again.

[0155] 54, in this embodiment, the left pressed rib 716L of the developing unit 7 is formed at the front end of the side holder 719a. In addition, in accordance with this, the left pressing portion 640L1 is also disposed shifted to the left as shown in FIG.

[0156] [Summary of the eleventh embodiment] By doing so, the housing 700 of the developing unit 7 can be expanded forward, the volume of the toner storage section 74 can be increased, and the amount of toner that can be stored can be increased.

[0157] <Twelfth embodiment> Next, the configuration of the process cartridge 5 according to the twelfth embodiment will be described with reference to Figures 54 and 55. In the following description, only the parts that are different from the first embodiment will be described, and the other parts will be given the same names / reference numerals and will not be described again.

[0158] As shown in FIG. 56, in this embodiment, the drum unit 6 includes a corona charger 910, a pre-exposure unit 920, and a collection roller 930 disposed around the photosensitive drum 61. The corona charger 910 is a charging unit that charges the surface of the photosensitive drum 61 without contact. The pre-exposure unit 920 includes a light-emitting diode (LED) as a light source and a light guide as a light-guiding member. Light emitted from the LED is guided by the light guide and irradiates the surface of the photosensitive drum 61. Current is supplied to the LED from the device main body 2. The surface of the photosensitive drum 61 is neutralized by the light irradiation from the pre-exposure unit 920. A predetermined voltage is applied to the collection roller 930 from the device main body 2, which collects toner and other foreign matter, such as paper dust and dirt, adhering to the surface of the photosensitive drum 61.

[0159] Around the photosensitive drum 61, a transfer roller 63, a pre-exposure section 920, a recovery roller 930, a corona charger 910, and a developing roller 71 are arranged in this order from upstream to downstream in the direction of rotation (arrow 61a) during image formation.

[0160] [Summary of the twelfth embodiment] In this way, the drum unit 6 may be configured to include the corona charger 910, the pre-exposure unit 920, etc. The inventions described in the above-mentioned embodiments may be combined in this manner. Also, in the above-mentioned embodiments, the developing roller 71 contacts the photosensitive drum 61, but the developing roller 71 may be pressed against the photosensitive drum 61 so as to face the photosensitive drum 61 with a small gap therebetween, and the toner may be developed onto the photosensitive drum 61 through this small gap.

[0161] Furthermore, although the above-described embodiment has been described taking an electrophotographic printer 1 as an example, the present invention is not limited to this. For example, the present invention may also be applied to an inkjet image forming apparatus that forms an image on a sheet by ejecting ink liquid from nozzles. [Explanation of symbols]

[0162] 5: cartridge (process cartridge) / 6: drum unit / 7: developing unit / 61: photosensitive drum / 68a: exposure hole (electrode exposure hole) / 71: developing roller / 85: memory / 800: recess (collection recess) / 810: cleaning member (sheet member) / 610: frame

Claims

1. A drum unit having a photosensitive drum that rotates about a rotation axis extending in a first direction, and a frame that rotatably supports the photosensitive drum, A developing unit having a developing roller that supplies toner to the photosensitive drum, which is detachable from the drum unit and mounted on the drum unit, A cartridge equipped with, The drum unit has a pressing member that presses the developing unit so that the developing roller and the photosensitive drum come into contact. The aforementioned frame is A through-hole extending through the frame in a second direction perpendicular to the first direction, into which a part of the developing unit enters, A recess adjacent to the through hole in the first direction and recessed toward the side away from the developing unit in the second direction, The first portion is a part of the frame adjacent to the recess, It has, When one end of the frame in the first direction is designated as the first end and the other end as the second end, At the first end, the through hole, the recess, and the pressing member are arranged in this order in the first direction, from the first end to the second end. The position of the pressing member in the first direction does not coincide with the position of the through hole in the first direction, and coincides with the position of the first portion in the first direction. A cartridge characterized by the following features.

2. The position of the pressing member in the first direction coincides with the position of a part of the recess in the first direction. The cartridge according to feature 1.

3. When the recess is the first recess, The drum unit further has a second recess which is different from the first recess and adjacent to the through hole. The cartridge according to feature 1.

4. In a third direction intersecting both the first and second directions, the developing roller is provided at the end of the developing unit, In the third direction, the second recess is positioned closer to the photosensitive drum than the first recess. The cartridge according to feature 3.

5. The length of the second recess in the third direction is longer than the length of the first recess in the third direction. The cartridge according to feature 4.

6. The frame has a second portion which is a part of the frame adjacent to the second recess, The position of the pressing member in the first direction coincides with the position of the second portion in the first direction. The cartridge according to any one of claims 3 to 5.

7. The first part and the second part are connected, The cartridge according to feature 6.

8. When the through hole is the first through hole, The frame has a second through hole that is different from the first through hole, In the first direction, the first through hole, the recess, the pressing member, and the second through hole are arranged in this order from the first end toward the second end. The cartridge according to feature 1.

9. The first portion is located between the recess and the second through hole in the first direction. The cartridge according to feature 8.

10. The second through hole is formed in the central part of the drum unit in the first direction. The cartridge according to feature 8 or 9.

11. The opening area of ​​the second through hole is larger than the opening area of ​​the first through hole. The cartridge according to any one of claims 8 to 10.

12. The drum unit has a gear that transmits drive to the photosensitive drum, The gear is positioned at the first end, The position of the gear in the first direction coincides with the position of the through hole in the first direction. The cartridge according to any one of claims 1 to 11.

13. When the gear that transmits drive to the photosensitive drum is the first gear, The developing unit has a second gear that transmits drive to the developing roller, and the second gear is located at the first end. The cartridge according to feature 12.

Images