cartridge

Abstract

To provide a technique that can increase the capacity of a space for storing toner in a process cartridge.SOLUTION: A developing unit 270 removably attached to a photoreceptor unit 260 has: a developing roller 71 that supplies toner to a photoreceptor drum 61 and recovers a toner remaining on a surface of the photoreceptor drum 61; a housing 250 that is formed with a storage space for storing toner; and a pressing receiving part that receives a pressing force exerted by a pressing member 200. The housing 250 has, in an attitude during use, an arcuate first bottom part projecting toward the outside of the storage space, and an arcuate second bottom part projecting toward the outside of the storage space. When seen from a direction along the axis of rotation of the developing roller 71, at least part of the pressing receiving part is arranged in a space surrounded by a tangent line in contact with an outer wall of the first bottom part and an outer wall of the second bottom part, the first bottom part, and the second bottom part.SELECTED DRAWING: Figure 18

Description

[Technical field]

[0001] The present invention relates to a cartridge for a photoconductor unit, a developing unit, or the like, which can be attached to or detached from an electrophotographic image forming apparatus. [Background technology]

[0002] In electrophotographic image forming apparatuses such as laser beam printers and copiers, a toner image is formed on a photosensitive drum, and the toner image is transferred to a sheet serving as a recording material to form an image on the recording material. In laser beam printers, in order to facilitate maintenance, a method is widely adopted in which some parts of the image forming apparatus are provided in a cartridge, and the cartridge is removed from the main body of the apparatus for maintenance and replacement. Patent Document 1 discloses a process cartridge in which a developing unit that contains toner can be detachably attached to a photosensitive unit having a photosensitive drum. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-224221 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a process cartridge having a structure in which a developing unit that contains toner can be detachably attached to a photosensitive unit having a photosensitive drum, there is still room for further improvement in terms of size, cost, accuracy, usability, lifespan, etc.

[0005] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a technique capable of increasing the capacity of the space for storing toner in a process cartridge. [Means for solving the problem]

[0006] In order to achieve the above object, a process cartridge according to one embodiment of the present invention includes a photosensitive unit and a developing unit detachably attached to the photosensitive unit, The photoconductor unit includes: a photoconductor drum on which an electrostatic latent image is formed; A frame supporting the photosensitive drum; a pressing member that presses the developing unit toward the photoconductor unit, The developing unit comprises: a developing roller that supplies toner to the photosensitive drum and collects toner remaining on the surface of the photosensitive drum; a housing having a storage space for storing toner; a pressure receiving portion that receives a pressing force from the pressing member, The housing includes: In a posture during use, the container has a first bottom portion having an arc shape protruding toward the outside of the storage space, and a second bottom portion having an arc shape protruding toward the outside of the storage space, When viewed from a direction along the rotation axis of the developing roller, at least a part of the pressure receiving portion is arranged in a space surrounded by a tangent line contacting an outer wall of the first bottom portion and an outer wall of the second bottom portion, the first bottom portion, and the second bottom portion. It is characterized by:

[0007] In order to achieve the above object, a process cartridge according to one embodiment of the present invention includes a photoconductor a developing unit detachably attached to the photoconductor unit, The photoconductor unit includes: a photoconductor drum on which an electrostatic latent image is formed; A frame supporting the photosensitive drum; a pressing member that presses the developing unit toward the photoconductor unit, The developing unit comprises: a developing roller that supplies toner to the photosensitive drum and collects toner remaining on the surface of the photosensitive drum; a housing having a storage space for storing toner; a pressure receiving portion that receives a pressing force from the pressing member, The housing includes: A first bottom portion having an arc shape protruding toward the outside of the storage space in a posture during use; a second bottom portion having an arc shape protruding toward the outside of the storage space; The first top surface and A second top surface provided above the first top surface in the direction of gravity; a connection portion connecting the first top surface and the second top surface, The connection portion has an opposing surface that faces the first top surface.

[0008] In order to achieve the above object, a process cartridge according to one embodiment of the present invention includes a photosensitive unit and a developing unit detachably attached to the photosensitive unit, The photoconductor unit includes: a photoconductor drum on which an electrostatic latent image is formed; a frame supporting the photosensitive drum; The developing unit comprises: a developing roller that supplies toner to the photosensitive drum and collects toner remaining on the surface of the photosensitive drum; a housing having a storage space for storing toner; a first conveying member that conveys toner toward the developing roller; a second transport member that transports the toner toward the first transport member, The housing includes: A first bottom portion having an arc shape protruding toward the outside of the storage space in a posture during use; and a second bottom portion having an arc shape protruding toward the outside of the storage space, The first conveying member is The stirring blade is disposed above the first bottom portion and has a rotating shaft and an agitating blade inclined with respect to the axis of the rotating shaft, The second conveying member is The mixing device is disposed above the second bottom portion and is characterized by having a rotating shaft and a stirring sheet having a slit.

[0009] In order to achieve the above object, a process cartridge according to one embodiment of the present invention includes a photosensitive unit and a developing unit detachably attached to the photosensitive unit, The photoconductor unit includes: a photoconductor drum on which an electrostatic latent image is formed; a frame supporting the photosensitive drum; The developing unit comprises: a developing roller that supplies toner to the photosensitive drum and collects toner remaining on the surface of the photosensitive drum; a housing having a storage space for storing toner; a first conveying member that conveys the toner in the toner storage space toward the developing roller; a second conveying member that conveys the toner in the storage space toward the first conveying member; a third conveying member that conveys the toner in the storage space toward the second conveying member, The housing includes: A first bottom portion having an arc shape protruding toward the outside of the storage space in a posture during use; a second bottom portion having an arc shape protruding toward the outside of the storage space; and a third bottom portion having an arc shape protruding toward an outside of the storage space, the first conveying member is disposed above the first bottom portion; the second conveying member is disposed above the second bottom portion; The third conveying member is disposed above the third bottom portion. It is characterized by:

[0010] In order to achieve the above object, a process cartridge according to one embodiment of the present invention includes a photosensitive unit and a developing unit detachably attached to the photosensitive unit, The photoconductor unit includes: a photoconductor drum on which an electrostatic latent image is formed; a frame supporting the photosensitive drum; The developing unit comprises: a developing roller that supplies toner to the photosensitive drum and collects toner remaining on the surface of the photosensitive drum; a housing having a storage space for storing toner; a rotatable first conveying member that conveys the toner in the toner storage space toward the developing roller; a rotatable second conveying member that conveys the toner in the storage space toward the first conveying member; a third conveying member that conveys the toner in the storage space toward the second conveying member, The housing includes: A first bottom portion having an arc shape protruding toward the outside of the storage space in a posture during use; a second bottom portion having an arc shape protruding toward the outside of the storage space; and a third bottom portion having an arc shape protruding toward an outside of the storage space, the first conveying member is disposed above the first bottom portion; the second conveying member is disposed above the second bottom portion; the third conveying member is disposed above the third bottom portion, when viewed from a direction along the rotation axis of the first conveying member, in a direction along which a straight line passing through a rotation center of the first conveying member and a rotation center of the second conveying member extends, at least a part of the third bottom portion extends in a direction away from the photosensitive drum further than an end portion of the photosensitive unit on an opposite side to one side on which the photosensitive drum is disposed. It is characterized by: Effect of the Invention

[0011] According to the present invention, the volume of the space for storing toner in the process cartridge can be increased. [Brief description of the drawings]

[0012] [Figure 1]1 is a cross-sectional view of an image forming apparatus equipped with a process cartridge. [Diagram 2] Cross-sectional view of the development unit [Diagram 3] FIG. [Figure 4] Exploded perspective view of the developing unit [Diagram 5] Cross-sectional view of a process cartridge [Figure 6] Top view of the development unit [Figure 7] FIG. 3 is a perspective view of a process cartridge [Figure 8] Detector member [Figure 9] FIG. [Figure 10] FIG. 3 is a perspective view of a process cartridge [Figure 11] Partial perspective view of a photoconductor unit [Figure 12] A perspective view of a developing unit and a photoconductor unit. [Figure 13] Top view of the developing unit and photoconductor unit [Figure 14] FIG. 3 is a perspective view of a process cartridge [Figure 15] FIG. 2 is a partial perspective view of the developing unit and the lift member; [Figure 16] FIG. 1 is a diagram showing the positional relationship between a lift member and a pressing member; [Figure 17] A diagram showing the removal of the developing unit. [Figure 18] 1 is a cross-sectional view of a process cartridge according to a first embodiment of the present invention; [Figure 19] 11 is a cross-sectional view of a process cartridge according to a second embodiment of the present invention; [Figure 20] 13 is a top view of a process cartridge according to a third embodiment. [Figure 21] 13 is a top view of a process cartridge according to a fourth embodiment. [Figure 22] 11 is a cross-sectional view of a process cartridge according to a fourth embodiment of the present invention; [Figure 23] Examples of shapes that the notch on the stirring sheet according to Example 4 can take [Figure 24] Examples of possible shapes of holes on the stirring sheet according to Example 4 [Diagram 25] 11 is a cross-sectional view of a process cartridge according to a fourth embodiment of the present invention; [Figure 26] FIG. 13 is an explanatory diagram of an image forming apparatus equipped with a process cartridge according to a sixth embodiment of the present invention. [Figure 27] FIG. 13 is an explanatory diagram of an image forming apparatus equipped with a process cartridge according to a sixth embodiment of the present invention. [Figure 28] 13 is a cross-sectional view of a process cartridge according to a sixth embodiment of the present invention; [Figure 29] 13 is a cross-sectional view of a process cartridge according to a sixth embodiment of the present invention; [Diagram 30] FIG. 13 is a perspective view of a process cartridge according to a sixth embodiment of the present invention; [Diagram 31] 13 is a cross-sectional view of a process cartridge according to a sixth embodiment of the present invention; [Diagram 32] 13 is a cross-sectional view of a process cartridge according to a fifth embodiment of the present invention; [Diagram 33] 13 is a cross-sectional view of a process cartridge according to a fifth embodiment of the present invention; [Diagram 34] 13 is a top view of a process cartridge according to the fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, the embodiment of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in the embodiment may be changed as appropriate depending on the configuration and various conditions of the device to which the invention is applied. In other words, the scope of the present invention is not limited to the following embodiment.

[0014] First, an image forming apparatus and a process cartridge according to an embodiment of the present invention will be described in detail with reference to the drawings as appropriate. Fig. 1 is a cross-sectional view of an image forming apparatus 1 equipped with a process cartridge 5.

[0015] In the following description, directions are defined based on the user who uses the image forming apparatus 1. In other words, the front side of the image forming apparatus 1 is referred to as the "front", the rear side as the "rear", the top (top) side as the "upper", and the lower (bottom) side as the "lower". In addition, the left side of the image forming apparatus 1 when viewed from the front side is referred to as the "left" and the right side as the "right". The orientation of the image forming apparatus 1 shown in each drawing indicates the orientation during use, and the directions of the process cartridge 5 are defined in the same manner as those of the image forming apparatus 1, assuming that the process cartridge 5 is in the same orientation as when it is attached to the image forming apparatus 1. Each direction in each drawing is defined by an arrow shown in the drawing. The front-rear direction, up-down direction, and left-right direction indicated by these arrows are mutually orthogonal. These directions are the same in all drawings. The up-down direction is parallel to the vertical direction, and the left-right direction and front-rear direction are parallel to the horizontal direction. In addition, the left-right direction is parallel to the rotation axis direction of the photosensitive drum 61 and the development They are parallel to the direction of the rotation axis of roller 71. Moreover, the developing unit 7 and the photosensitive unit 6 are mounted together and integrated together to form a process cartridge 5. This process cartridge 5 is inserted in the direction of arrow S1 in the figure when mounted in the apparatus main body 2 (mounting direction), and is removed in the direction of arrow S2 in the figure.

[0016] <Overall configuration of image forming apparatus> As shown in FIG. 1, the image forming apparatus 1 mainly includes a paper feed section 3 for feeding paper S into the apparatus main body 2, an exposure device 4, a process cartridge 5 for transferring a toner image onto the paper S, and a fixing device 8 for thermally fixing the toner image transferred onto the paper S. The paper feed section 3 is provided at the bottom of the apparatus main body 2, and mainly includes a paper feed tray 31 and a paper feed mechanism 32. The paper S stored in the paper feed tray 31 is fed toward the process cartridge 5 (between the photosensitive drum 61 and the transfer roller 63) by the paper feed mechanism 32. The exposure device 4 is provided at the top of the apparatus main body 2, and includes a laser emission section (not shown), a polygon mirror (not shown), a lens, a reflecting mirror, and the like (not shown). In the exposure device 4, a laser beam based on image data emitted from the laser emission section is scanned at high speed on the surface of the photosensitive drum 61, thereby exposing the surface of the photosensitive drum 61.

[0017] The process cartridge 5 is disposed below the exposure device 4. It is inserted in an insertion direction S1 into a storage section 23 of the apparatus body 2 from an opening formed when a door (opening member) 21 provided on the apparatus body 2 is opened (shown by a two-dot chain line in FIG. 1), and is then attached to the apparatus body 2. When removing the process cartridge 5 from the apparatus body 2, the process cartridge 5 is moved in a removal direction S2 and taken out. This process cartridge 5 mainly includes a photosensitive unit 6 and a developing unit 7. The photosensitive unit 6 mainly includes a photosensitive drum 61, a charging device 62, and a transfer roller 63. The developing unit 7 is configured to be detachably attached to the photosensitive unit 6. The developing unit 7 mainly comprises a developing roller 71, a supply roller 72, a layer thickness regulating blade 73, a toner storage section (developer storage section) 74 that stores toner (developer), and a first agitator 75A and a second agitator 75B provided in the toner storage section 74.

[0018] <Image formation process> Next, a description will be given of an image forming process using this process cartridge 5. The photoconductor drum 61 is rotationally driven during the image forming process. First, the surface of the photoconductor drum 61 is uniformly charged by the charging device 62, and then exposed to a laser beam corresponding to image data emitted from the exposure device 4, thereby forming an electrostatic latent image corresponding to the image data on the photoconductor drum 61.

[0019] On the other hand, the toner 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 via the supply roller 72. The toner supplied to the developing roller 71 enters between the developing roller 71 and the layer thickness regulating blade 73 and is carried on the developing roller 71 as a thin layer of a certain thickness. The toner carried on the developing roller 71 is supplied to the electrostatic latent image formed on the photosensitive drum 61. As a result, the toner adheres to the electrostatic latent image and is made visible, and a toner image is formed on the photosensitive drum 61. Thereafter, the paper S is transported between the photosensitive drum 61 and the transfer roller 63, and the toner image on the photosensitive drum 61 is transferred onto the paper S. At this time, the transfer residual toner remaining on the photosensitive drum 61 is collected by the developing roller 71 and returned to the developing unit 7.

[0020] The fixing device 8 is disposed at the rear of the process cartridge 5, and mainly includes a heating roller 92 and a pressure roller 91. The paper S onto which the toner image has been transferred passes through this fixing device 8, during which the paper S is heated and pressurized between the heating roller 92 and the pressure roller 91, and the toner image is fixed onto the paper S. The paper S that has passed through the fixing device 8 is discharged onto the paper discharge tray 22. will be done.

[0021] <Process cartridge configuration> Next, a description will be given of each unit of the process cartridge 5. As described above, the process cartridge 5 includes the photosensitive unit 6 and the developing unit 7 which is detachable from the photosensitive unit 6.

[0022] <Developing unit configuration> First, the configuration of the developing unit 7 will be described. FIG. 2 is a cross-sectional view of the developing unit 7, and is a cross-sectional view taken along the line AA in FIG. 3. FIG. 3 is a perspective view of the developing unit 7 seen from above, and FIG. 7 is a perspective view of the process cartridge 5 seen from above. FIG. 4 is an exploded perspective view of the developing unit 7. FIG. 5 is a cross-sectional view of the developing unit 7 attached to the photosensitive unit 6, and the cross section is parallel to the up-down direction and the front-rear direction. FIG. 6 is a top view of the developing unit 7, and shows a state in which the top surface of the housing 700 and the side holder 719 have been removed for the sake of explanation.

[0023] 2, the developing unit 7 has a gripping portion 701 to be gripped by a user at the front of a housing 700 serving as a developing frame, and a developing roller 71 is rotatably supported at the rear. Hereinafter, the configuration of the developing unit 7 will be described with the direction of the rotation axis of the developing roller 71 being referred to as the axial direction.

[0024] 4 and 6, the developing roller 71, the supply roller 72, the first agitator (first agitating member) 75A, and the second agitator (second agitating member) 75B are each rotatably supported at both ends by a left side wall 704 and a right side wall 705 of the housing 700. On the left side of the left side wall 704 of the housing 700, a developing coupling 710, a developing roller gear 711, a supply roller gear 712, a first agitator gear 713, a second agitator gear 714, and idle gears 715A, 715B, and 715C are provided. The developing roller gear 711 is fixed to an end of the developing roller 71, and the supply roller gear 712 is fixed to an end of the supply roller 72. Also, the first agitator gear 713 is fixed to an end of the stirring rod 78A (see FIG. 5) of the first agitator 75A, and the second agitator gear 714 is fixed to an end of the stirring rod 78B (see FIG. 5) of the second agitator 75B.

[0025] 3, the developing unit 7 is provided with a first electrical contact 720A electrically connected to the developing roller 71 and supplied with a voltage to be applied to the developing roller 71, and a second contact 720B electrically connected to the supply roller 72 and supplied with a voltage to be applied to the supply roller 72. These electrical contacts come into contact with a power supply contact (not shown) provided in the apparatus main body 2, thereby supplying power to the developing roller 71 and the supply roller 72.

[0026] In conjunction with the operation of closing the door 21 provided in the apparatus main body 2, a developing drive transmission member (not shown) provided in the apparatus main body 2 moves to a position for engaging with the developing coupling 710. Conversely, in conjunction with the operation of opening the door 21, the developing drive transmission member moves to a position for releasing the engagement with the developing coupling 710.

[0027] When the apparatus main body 2 is operated after the door 21 is closed, a driving force is transmitted (input) from the developing drive transmission member to the developing coupling 710 serving as a driving force receiving member. This driving force allows the developing roller 71 to rotate via the developing roller gear 711 and the supply roller 72 to rotate via the supply roller gear 712 from gears provided on the circumferential surface of the developing coupling 710. The developing drive transmission member is configured to transmit the driving force to the developing coupling 710 while allowing the developing coupling 710 to shift in position within a predetermined range. 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 attached to the housing 700.

[0028] The developing unit 7 employs two agitators, a first agitator 75A and a second agitator 75B, to agitate the toner in the toner storage section 74. The first agitator 75A includes an agitating rod 78A and an agitating sheet 79A. The first agitator 75A is configured to be rotatable by receiving a driving force from the developing coupling 710 via an idle gear 715A at a first agitator gear 713. The second agitator 75B includes an agitating rod 78B and an agitating sheet 79B. The second agitator 75B is configured to be rotatable by receiving a driving force from the first agitator gear 713 via idle gears 715B and 715C at a second agitator gear 714.

[0029] The second agitator 75B supplies the toner in the toner storage unit 74 to the first agitator 75A. The toner near the first agitator 75A in the toner storage unit 74 is agitated by the first agitator 75A, and then supplied to the supply roller 72, and further supplied to the developing roller 71 by the supply roller 72.

[0030] 4 and 7, a detection section 80 is provided at the left end of the developing unit 7. The detection section 80 is provided so that the state of a detection member 81 provided inside can be detected by a detection mechanism (not shown) provided in the apparatus main body 2. Depending on the state of this detection member 81, it can be determined whether the developing unit 7 is unused or has already been used.

[0031] The operation of the detection member 81 will be described with reference to Figures 8(a) and 8(b). Figures 8(a) and 8(b) are views of the developing unit 7 as seen from the left side. For the sake of explanation, the side holder 719 has been removed. As shown in Figure 8(a), the detection member 81 is provided with a detection protrusion 83 and a detection gear 82. As shown in the figure, the detection gear 82 is a gear with missing teeth. The detection member 81 receives a driving force from the second agitator gear 714 to the detection gear 82.

[0032] 8(a) shows the developing unit 7 in an unused state. The detection protrusion 83 is located above and in front of the detection member 81. The detection gear 82 is engaged with the second agitator gear 714. When the developing unit 7 is used, the second agitator gear 714 rotates in the direction of arrow R3 in the figure due to the driving force received by the development coupling 710 from the development drive transmission member of the apparatus main body 2. At this time, since the detection gear 82 is engaged with the second agitator gear 714, the detection member 81 rotates in the direction of arrow R4 in the figure.

[0033] 8(b) shows the state after the detection member 81 has rotated. Since the detection gear 82 is a gear with missing teeth, the detection member 81 rotates in the direction of arrow R4 in the figure, and when there are no more gear teeth that mesh with the second agitator gear 714, the detection member 81 stops rotating. At this time, the detection protrusion 83 is located on the upper rear side of the detection member 81. By detecting the position of the detection protrusion 83 of the detection member 81 with a detection mechanism (not shown) provided in the apparatus body 2, it is possible to determine whether the development unit 7 is unused or has already been used.

[0034] 9 is a perspective view of the developing unit 7 as seen from below. As shown in the figure, the bottom surface of the developing unit 7 is provided with a memory 85 and a positioning protrusion 86. The memory 85 is provided with a memory chip (not shown) that stores information about the developing unit 7, and a memory electrode 85A that is electrically connected to the memory chip. The memory electrode 85A contacts an electrode (not shown) provided on the device body 2, and communicates between the memory chip and the device body 2.

[0035] <Photoconductor unit structure and development unit support> Next, a detailed configuration of the photosensitive unit 6 will be described. Fig. 10 is a perspective view of the process cartridge 5. Fig. 11(a) is a partial perspective view of the photosensitive unit 6, and Fig. 11(b) is a partial perspective view of the photosensitive unit 6. It is a cross-sectional view taken along line B-B in Fig. 11(a). Fig. 12 is a perspective view of the developing unit 7 and the photosensitive unit 6. Fig. 13 is a top view showing the left-right positional relationship between the photosensitive unit 6, the developing unit 7, and the developing roller 71. Fig. 14(a) is a perspective view of the process cartridge 5 seen from below, and Fig. 14(b) is a perspective view of the positioning portion of the developing unit 7 and the photosensitive unit 6 in the axial direction of the photosensitive drum 61. For the sake of explanation, Fig. 14(b) shows only the positioning protrusion 86 and the marking 85 of the developing unit 7.

[0036] As shown in Fig. 10, the photoconductor unit 6 mainly includes a frame 610 having a pair of left side walls 611 and right side walls 612, and a photoconductor drum 61 rotatably supported at the rear of the frame 610. At the front of the frame 610, there are provided a mounting portion 615 (see Fig. 12) to which the developing unit 7 can be mounted, a gripping portion 617 with which the user grips the photoconductor unit 6, a pressing member 640 that presses the developing unit 7, and a lift member (moving member) 642 that lifts the developing unit 7. The lift member 642 presses and moves the developing unit 7 mounted in the mounting portion 615. The toner storage portion 74 of the developing unit 7 mounted in the mounting portion 615 is disposed between the left side wall 611 and the right side wall 612 in the left-right direction.

[0037] A first positioning protrusion 660 and a first guide rib 662 are provided at the rear of the frame 610, protruding coaxially with the photosensitive drum from the left side wall 611. Similarly, a second positioning protrusion 661 and a second guide rib 663 are provided at the rear of the frame 610, protruding coaxially with the photosensitive drum from the right side wall 612 (see FIGS. 10 and 13).

[0038] The life of the developing unit 7, which is determined by the amount of toner stored in the developing unit 7, is set to be shorter than the life of the photosensitive unit 6, which is determined by the thickness of the photosensitive layer of the photosensitive drum 61. Therefore, it is necessary to replace only the developing unit 7 that has reached the end of its life separately from the photosensitive unit 6. In this case, the door 21 is opened, the process cartridge 5 is removed from inside the apparatus main body 2, the developing unit 7 that has reached the end of its life is removed from the photosensitive unit 6, and another developing unit 7 is attached to the photosensitive unit 6 as shown in the attachment direction AD in FIG. 12. Thereafter, the photosensitive unit 6 with the developing unit 7 attached thereto is attached to the apparatus main body 2 as the process cartridge 5.

[0039] 7, 10 and 12, a receiving portion 641 for receiving the rotation bearing members 746A and 746B of the developing roller 71 is formed on the left side wall 611 and the right side wall 612 of the frame 610, ahead of the photosensitive drum 61. The receiving portion 641 is a generally U-shaped recess with an open front side when viewed from the left side, into which the rotation shaft 746 of the developing roller 71 is inserted during the process of mounting the developing unit 7 to the photosensitive unit 6. The receiving portion 641 supports the developing unit 7 on the photosensitive unit 6, while guiding the movement of the developing unit 7 in the mounting direction AD shown in FIG.

[0040] 13, protrusions 643 protruding upward are provided on both left and right ends of the bottom surface 613 of the frame 610. These protrusions 643 abut against ribs 718 provided on the bottom of the housing 700 of the developing unit 7 shown in FIG. 9, thereby supporting the developing unit 7 so that the developing unit 7 can be moved.

[0041] As shown in Figure 12, the photosensitive unit 6 has a positioning hole 68 and a contact opening 69 provided in a frame 610 at one end in the direction of the rotation axis of the photosensitive drum 61 (left and right direction). Here, one end refers to the same side with respect to a line dividing the length of the photosensitive drum 61 in the left and right direction. When the developing unit 7 is installed on the photosensitive unit 6, as shown in Figures 14(a) and 14(b), the positioning protrusion 86 of the developing unit 7 is inserted into the positioning hole 68 of the photosensitive unit 6. The positioning protrusion 86 and the positioning hole 68 are fitted together in the axial direction of the photosensitive drum 61 (left and right direction), and the developing unit 7 is aligned with the photosensitive unit 6. The left-right position of the developing unit 7 is determined. The memory 85 of the developing unit 7 is exposed to the lower part of the process cartridge 5 through the contact opening 69 of the photosensitive drum 61.

[0042] Here, as shown in FIG. 11(a) and FIG. 14(b), a box-shaped recess 90L is provided on one end side of the rotation axis direction (left-right direction) of the photosensitive drum 61 in the frame 610 of the photosensitive drum unit 6. The recess 90L is provided at a position overlapping with the positioning hole 68 when viewed from the rotation axis direction (left-right direction) of the photosensitive drum 61. The recess 90L reinforces the surrounding area whose strength has been reduced by providing the positioning hole 68, thereby increasing its strength. As shown in FIG. 11(b), the depth D2 of the recess 90L is deeper than the depth D1 of the positioning hole 68, increasing the effect of reinforcement. This configuration increases the strength around the positioning hole 68 of the photosensitive drum unit 6, and increases the positioning accuracy of both units in the left-right direction by the positioning protrusion 86 of the developing unit 7 and the positioning hole 68 of the photosensitive drum unit 6. As a result, the position accuracy of the memory electrode 85A of the memory 85 and the electrode provided in the device main body 2 increases, and reliable electrode abutment can be achieved.

[0043] As shown in FIG. 11(a) and FIG. 14(b), a sheet member 93L is provided on the photosensitive drum 61 side of the recess 90L. A tip portion 93LA of the sheet member 93L abuts against the photosensitive drum 61. With this configuration, foreign matter such as unnecessary toner and paper dust adhering to the surface of the photosensitive drum 61 during image formation is scraped off by the tip portion 93LA to prevent image defects. With this configuration, the scraped off foreign matter such as unnecessary toner and paper dust falls into the recess 90L and is collected. Therefore, contamination of the process cartridge 5 due to scattering of foreign matter and image defects due to falling of foreign matter onto the paper S can be prevented. By using the recess 90L as a reinforcing structure and for collecting foreign matter in this way, it is not necessary to provide a structure for collecting foreign matter separately from the recess 90L, and the cartridge can be made smaller and the structure can be simplified.

[0044] As shown in Fig. 12, a foreign matter box 90R having a box-shaped recess is provided on the left-right opposite side of the positioning hole 68 of the photoconductor unit 6. A sheet member 93R is provided on the photoconductor drum 61 side of the foreign matter box 90R. A tip portion 93RA of the sheet member 93R abuts against the photoconductor drum 61. As with the above-mentioned sheet member 93L, the tip portion 93RA scrapes off foreign matter such as unnecessary toner and paper powder that adheres to the surface of the photoconductor drum 61 during image formation, preventing image defects. The scraped off foreign matter such as unnecessary toner and paper powder falls into the foreign matter box 90R and is collected in the box.

[0045] 12, the pressing member 640 is located in front of the frame 610 and is provided at both ends of the frame 610 in the left-right direction. The pressing member 640 is biased in the front-to-rear direction by a compression spring 640A serving as a biasing member. Therefore, the pressing member 640 presses the pressed ribs 716A and 716B provided on the housing 700 of the developing unit 7 by the biasing force of the compression spring 640A. By pressing the developing unit 7 with the pressing member 640, the developing roller 71 is biased toward the photosensitive drum 61.

[0046] 12 and 7, a recess 664 is provided in the left side wall 611 of the photoconductor unit 6, and the detection unit 80 of the developing unit 7 is located therein. Since the recess 664 reduces the rigidity of the frame 610, the first guide rib 662 is disposed so as to overlap a part of the lower part of the recess 664. Since the first guide rib 662 acts as a reinforcing member, it is possible to reduce the reduction in rigidity of the frame 610.

[0047] 11, a photosensitive gear (first gear) 65 and a transfer gear (second gear) 66 are fixed to the left end of the photosensitive drum 61, and are configured to rotate integrally with the photosensitive drum 61. When the process cartridge 5 is mounted in the main body 2 of the apparatus, a drive gear (not shown) of the main body 2 of the apparatus and the photosensitive gear 65 mesh with each other, so that the photosensitive drum 61 and the transfer gear 6 The driving force is transmitted to transfer roller 6, making it rotatable. Furthermore, transfer gear 66 meshes with transfer roller gear (third gear) 67 fixed to the left end of transfer roller 63, making transfer roller 63 also rotatable.

[0048] <Lift mechanism of developing unit 7> FIG. 15 is a partial perspective view of the developing unit 7 and the lift member 642. FIG. 16 is a top view of the photoconductor unit 6 to which the developing unit 7 is attached, with the lift member 642 shown see-through in FIG. 16(a) and the lift member 642 shown without see-through in FIG. 16(b). FIG. 17 is a cross-sectional view of the photoconductor unit 6 and the developing unit 7, with the cross-section parallel to the up-down direction and the front-rear direction. FIG. 17(a) shows the state in which the developing unit 7 is attached to the photoconductor unit 6, and FIG. 17(b) shows the state in which the developing unit 7 is placed on the photoconductor unit 6. The developing unit 7 attached to the photoconductor unit 6 is removed from the photoconductor unit 6 after being moved to a lifted-up state by a lift mechanism. This lift mechanism will be described in detail below.

[0049] 15 and 17, at least a part of the lift member 642 is disposed on the front side of the housing 700 of the developing unit 7, and is rotatably supported by the right side wall 612 while receiving the force of the compression spring 650. At least a part of the lift member 642 is disposed to overlap in the front-rear direction with the right side wall 705 of the housing 700 that contains toner and the pressing member 640. The rotation axis 642X of the lift member 642 is parallel to the left-right direction (the axial direction of the photosensitive drum 61). The lift member 642 is biased by the force of the compression spring 650 in a direction to rotate in the R1 direction.

[0050] When the user presses the operating portion 642A of the lift member 642 against the force of the compression spring 650 to rotate the lift member 642 in the R2 direction, the lift member 642 presses the protruding portion 751 and moves the developing unit 7 in the removal direction LD to remove it from the photosensitive unit 6. This makes the developing unit 7 ready to be removed from the photosensitive unit 6. The operating portion 642A is disposed on the right end side (one end side) of the photosensitive unit 6.

[0051] As shown in FIG. 17(a), in an attached state in which the developing unit 7 is attached to the photosensitive unit 6, the pressing member 640 presses the housing 700, thereby pressing the developing roller 71 against the photosensitive drum 61. In addition, the pressing member 640 locks the developing unit 7 so that it does not come off from the photosensitive unit 6. As shown in FIG. 15, one end of the lift member 642 moves the abutment surface (abutment portion) 751A of the protrusion 751 of the housing 700 upward. This allows the developing unit 7 to be moved in the removal direction LD from the attachment position where it is attached to the attachment portion 615 (see FIG. 12) and removed from the photosensitive unit 6.

[0052] As shown in FIG. 17(b), when the front part of the developing unit 7 is separated from the photosensitive unit 6, the developing unit 7 is held in a temporary support position where the supported surface 700c of the housing 700 is supported by the holding part 640B of the pressing member 640. In addition, the developing unit 7 in the temporary support position is in a state where the rotary bearing member 746B (746A) of the developing roller 71 is supported by the receiving part 641. This state is called a lift-up state. At this time, the lock (the restriction on removing the developing unit 7 from the photosensitive unit 6) is released. In this lift-up state, if the user grasps the grip part 701 and lifts the developing unit 7 as it is, the developing unit 7 can be removed from the photosensitive unit 6 without moving other members. In this way, the user can remove the developing unit 7 from the photosensitive unit 6 and attach a new developing unit 7 to the photosensitive unit 6.

[0053] [Example 1] Next, a first embodiment of the present invention will be described with reference to FIG. 18. In this embodiment, the parts different from the image forming apparatus 1 and the process cartridge 5 described above will be described in detail. Unless otherwise specified, the parts have the same configuration as the image forming apparatus 1 and the process cartridge 5 described above, so the same numbers are given to such parts and detailed description will be omitted. FIG. 18(a) is a cross-sectional view illustrating the pressing configuration of the developing unit 270 by the pressing member 200 when the developing unit 270 is attached to the photosensitive unit 260 in the first embodiment. FIG. 18(b) is a partial detailed view of the first wall surface 212 and the second wall surface 222 in FIG. 18(a). The first wall surface 212 and the second wall surface 222 will be described later.

[0054] 18(a), the photosensitive unit 260 is provided with a photosensitive drum 61, a frame 610, and a pressing member 200. The pressing member 200 is a pressing member that presses the developing roller 71 provided in the developing unit 270 toward the photosensitive drum 61 when the developing unit 270 is attached to the photosensitive unit 260.

[0055] The photoconductor unit 260 is provided with a paper dust removing roller 64A, a paper dust collecting roller 64B, and a paper dust collecting chamber 64C. The paper dust removing roller 64A abuts against the photoconductor drum 61, and is disposed downstream of the transfer roller 63 in the rotation direction of the photoconductor drum 61 and upstream of the charging device 62 in the rotation direction of the photoconductor drum 61. The paper dust collecting roller 64B abuts against the paper dust removing roller 64A, and is disposed rearward of the paper dust removing roller 64A. The paper dust collecting chamber 64C is a closed space formed by the paper dust collecting roller 64B and the frame 610. The paper dust removing roller 64A removes paper dust remaining on the photoconductor drum 61 from the photoconductor drum 61 after the toner image on the photoconductor drum 61 is transferred onto the paper S (? not shown). The paper dust removed by paper dust removing roller 64A is collected in paper dust collection chamber 64C by paper dust collection roller 64B.

[0056] A first agitator 211 and a second agitator 221 are provided inside the developing unit 270. The first agitator 211 is disposed in a first agitation chamber 210 provided in front of the developing roller 71 and the supply roller 72. The second agitator 221 is disposed in a second agitation chamber 220 provided in front of the first agitation chamber 210.

[0057] The first stirring chamber 210 is a space for accommodating toner, which is formed by a top surface 240 of the stirring chamber provided above the first agitator 211 in the direction of gravity, and a first wall surface 212 provided below the first agitator 211 in the direction of gravity. The second stirring chamber 220 is a space for accommodating toner, which is formed by a top surface 240 of the stirring chamber and a second wall surface 222 provided below the second agitator 221 in the direction of gravity. At least a part of the first wall surface 212 is a convex (arcuate) wall surface (bottom) protruding downward in the direction of gravity relative to the first agitator 211. At least a part of the second wall surface 222 is a convex (arcuate) wall surface (bottom) protruding downward in the direction of gravity relative to the second agitator 221.

[0058] 18(b), since the first wall surface 212 and the second wall surface 222 are convex wall surfaces that protrude downward in the direction of gravity, it is possible to draw a common tangent line T203 (broken line portion) that connects the outer wall surfaces of the bottoms of the first wall surface 212 and the second wall surface 222. Here, the area surrounded by the common tangent line T203, the first wall surface 212, and the second wall surface 222 (the cross-hatched area consisting of vertical and horizontal lines) is defined as a first recess 231.

[0059] The first recess 231 is formed at the boundary between the first wall surface 212 and the second wall surface 222 in the front-rear direction, and the first wall surface 212 and the second wall surface 222 are connected via the first recess 231. The first recess 231 is disposed between the rotation centers of the first agitator 211 and the second agitator 221 in the front-rear direction. The first recess 231 has a pressure receiving portion that receives a pressure from the pressing member 200. The pressure receiving portion 231A is provided with a pressure receiving portion 231A. When the pressure receiving portion 231A receives a pressing force from the pressing member 200 in the direction of the first line T201, the developing roller 71 comes into contact with the photosensitive drum 61 with a predetermined contact pressure. Here, the first line T201 is a straight line that is perpendicular to the rotation axis direction (left-right direction) of the developing roller 71 and passes through the first wall surface 212 and the second wall surface 222.

[0060] The rotation center of the second agitator 221 is located near the second line T202 in the vertical direction. Here, the second line T202 is perpendicular to the rotation axis direction (left-right direction) of the developing roller 71 and is a straight line connecting the rotation centers of the developing roller 71 and the first agitator 211. The second line T202 passes through the second mixing chamber 220.

[0061] From the viewpoint of stabilizing the left-right distribution of the contact pressure of the developing roller 71 against the photosensitive drum 61, it is preferable that the pressure receiving portion 231A and the pressing member 200 are provided at both ends of the frame 610 in the left-right direction. On the other hand, from the viewpoint of cost, it is also possible to reduce the number of parts by providing the pressure receiving portion 231A and the pressing member 200 near the center of the frame 610 in the left-right direction.

[0062] From the viewpoint of further stabilizing the contact pressure, the pressure receiving portion 231A and the pressing member 200 may be provided at both ends and near the center of the frame 610 in the left-right direction. In addition, from the viewpoint of reducing the size of the developing unit 270 in the left-right direction, the pressure receiving portion 231A and the pressing member 200 may be disposed closer to the center of the frame 610 in the left-right direction than the lift member 642, or may be disposed so as to overlap in the left-right direction within a range not protruding outside the lift member 642.

[0063] 18 according to the first embodiment includes a photosensitive unit 260 and a developing unit 270 detachably attached to the photosensitive unit 260. The photosensitive unit 260 includes a photosensitive drum 61 on which an electrostatic latent image is formed, a frame 610 supporting the photosensitive drum 61, and a pressing member 200 that presses the developing unit 270 toward the photosensitive unit 260. The developing unit 270 includes a developing roller 71 that supplies toner to the photosensitive drum 260 and collects toner remaining on the surface of the photosensitive drum, a housing 250 in which a first stirring chamber 210 and a second stirring chamber 220 (storage space) that accommodate the toner are formed, and a pressure receiving portion 231A that receives pressure from the pressing member 200.

[0064] The housing 250 has a first wall surface 212 (outer wall of the first bottom) in an arc shape (convex downward) protruding toward the outside of the first stirring chamber 210, and a second wall surface 222 (outer wall of the second bottom) in an arc shape (convex downward) protruding toward the outside of the second stirring chamber 220. When viewed from a direction along the rotation axis of the developing roller 71 (vertical upward in the plane of the drawing), at least a part of the pressure receiving portion 231A is arranged in the first recess 231 surrounded by the first wall surface 212, the second wall surface 222, and a common tangent line T203 that contacts the first wall surface 212 and the second wall surface 222.

[0065] This allows the pressing member 200 to be disposed in the first recess 231, which would normally be dead space, thereby making it possible to reduce the size of the developing unit 270. In other words, the capacity of the space for storing toner can be increased without making the developing unit larger.

[0066] Moreover, the developing unit 270 according to the first embodiment has, as members for transporting the toner in the storage space of the housing 250, a first agitator 211 (first transport member) which rotates so as to contact the inner wall of the first wall surface 212 and transports the toner, and a second agitator 221 (second transport member) which rotates so as to contact the inner wall of the second wall surface 222 and transports the toner. The pressure receiving portion 231A is disposed between the rotation center of the first agitator 211 and the rotation center of the second agitator 221 in the horizontal direction.

[0067] In the process cartridge 5 according to the first embodiment, when a first line T201 is defined as an extension line that passes through the point where the pressing member 200 contacts the pressure receiving portion 231A and is parallel to the pressing direction of the pressing member 200, the first line T201 passes through (crosses) the first wall surface 212 and the second wall surface 222. In the process cartridge 5 according to the first embodiment, when viewed from the direction along the rotation axis of the developing roller 71, a second line T202 that passes through the rotation center of the developing roller 71 and the rotation center of the first agitator 211 passes through the second stirring chamber 220 serving as a transport chamber that houses the second agitator 221.

[0068] <Actions and Effects of Example 1> In the process cartridge 5 according to this embodiment, the pressing member 200 is provided in the first recess 231, so that the pressing force receiving portion 231A receives a pressing force from the pressing member 200 in the direction of the first line T201. The pressing force receiving portion 231A is provided on a side (rear side) closer to the developing roller 71 than the second wall surface 222 in the front-rear direction. Therefore, it is possible to suppress deformation of the housing 250 due to the pressing force, compared to a configuration in which the second wall surface 222 is provided on a side (front side) farther from the developing roller 71 than the first wall surface 212 in the front-rear direction. As a result, it is possible to reduce the loss of the contact pressure of the developing roller 71 against the photosensitive drum 61 due to deformation of the housing 250.

[0069] In this embodiment, since the pressing member 200 is provided in the first recess 231, it is possible to save space in the horizontal direction (front-rear direction) compared to a case in which the pressing member 200 is provided in front of the second wall surface 222. In addition, compared to a configuration in which the pressing member 200 is used to bias a portion of either the first wall surface 212 or the second wall surface 222 that is lower in the direction of gravity than the first recess 231, the process cartridge 5 according to Example 1 can save space in the vertical direction.

[0070] In this embodiment, the center of rotation of the second agitator 221 is located near the second line T202 in the vertical direction. The second line T202 is inclined toward the horizontal line (front-rear direction) rather than the vertical line (vertical direction), so that the vertical drop between the first agitation chamber 210 and the second agitation chamber 220 is kept low. Therefore, the vertical (height) size of the developing unit 270 can be reduced, so that the vertical (height) size of the process cartridge 5 and the image forming apparatus 1 can be reduced. In addition, the drop (height) of the toner during the toner transport from the second agitation chamber 220 to the first agitation chamber 210 by the second agitator 221 is kept low, so that the increase in powder pressure due to the accumulation of toner in the vertical direction can be prevented. Therefore, deterioration due to the increase in powder pressure of the toner is suppressed, so that the life of the developing unit 270 can be further extended.

[0071] In addition, in this embodiment, the pressure receiving portion 231A and the pressing member 200 are disposed closer to the center of the frame 610 in the left-right direction than the lift member 642, thereby making it possible to reduce the left-right (width) size of the developing unit 270. This makes it possible to reduce the left-right (width) size of the process cartridge 5 and the image forming apparatus 1.

[0072] In this embodiment, since the pressing member 200 is provided in the first recess 231, the first recess 231 and the pressing member 200 can be used as an engagement concave-convex shape for preventing erroneous installation between a plurality of process cartridges having different specifications such as life span and speed. Specifically, if the first recess 231 of the developing unit 270 is provided at a position different from the pressing member 200 of the photosensitive unit, when the developing unit 270 is installed in the photosensitive unit 260, either the first wall surface 212 or the second wall surface 222 will abut against the pressing member 200. In such a case, the developing unit 270 cannot be installed up to the installation completion position as shown in FIG. 18(a), and therefore it is possible to make the user aware of the erroneous installation of the developing unit 270. do.

[0073] [Example 2] Next, a second embodiment of the present invention will be described with reference to FIG. 19. In this embodiment, differences from the previous embodiment will be described in detail. Unless otherwise specified, the configuration is the same as in the previous embodiment, and therefore the same numbers are given to such portions, and detailed description will be omitted. FIG. 19 is a cross-sectional view for explaining the pressing configuration of the developing unit 271 by the pressing member 201 when the developing unit 271 is attached to the photoconductor unit 261 in the second embodiment.

[0074] As shown in FIG. 19, the photoconductor unit 261 is provided with a photoconductor drum 61, a frame 610, and a pressing member 201. The pressing member 201 is provided in front of a housing 251 of the developing unit 271, and presses the housing 251 in the direction of an arrow 201F when the developing unit 271 is attached to the photoconductor unit 261. Here, the arrow 201F is a pressing force vector that presses the developing roller 71 provided in the developing unit 271 toward the photoconductor drum 61. The arrows 201H and 201V are the horizontal component (front-rear force component) and vertical component (up-down force component) of the pressing force vector 201F, respectively. The pressing force horizontal component 201H is directed from the front to the rear, and the pressing force vertical component 201V is directed from the top to the bottom.

[0075] The first recess 231 of the developing unit 271 is provided with a rotation stopper 202 as an alternative to the protrusion 643 shown in FIG. 13. The rotation stopper 202 regulates the rotation of the developing unit 271 relative to the photosensitive unit 261. The rotation stopper 202 is composed of a rotation stopper roller 202A and a roller support portion 202B that supports the rotation stopper roller 202A. The rotation stopper roller 202A is supported rotatably by the roller support portion 202B and has a cylindrical or spherical shape. The roller support portion 202B is fixedly supported by the frame 610. The rotation stopper roller 202A abuts against the pressure receiving portion 231A to support the developing unit 271 movably relative to the photosensitive unit 261.

[0076] At this time, the pressure receiving portion 231A receives a reaction force in the direction of the arrow 202F from the rotation stop roller portion 202A. That is, the arrow 202F is a vector of the rotation stop abutment force that restricts the rotational freedom of the developing unit 271 around the developing roller 71. The arrows 202H and 202V respectively represent the horizontal component (front-rear direction) and vertical component (up-down direction) of the rotation stop abutment force 202F. The direction of the horizontal component 202H is from the front to the rear, and the direction of the vertical component 202V is from the bottom to the top.

[0077] From the viewpoint of stabilizing the left-right distribution of the contact pressure of the developing roller 71 against the photosensitive drum 61, it is preferable to provide the pressure receiving portion 231A and the rotation stopping portion 202 at both ends of the frame 610 in the left-right direction. On the other hand, from the viewpoint of cost, it is also possible to reduce the number of parts by providing the pressure receiving portion 231A and the rotation stopping portion 202 near the center of the frame 610 in the left-right direction.

[0078] From the viewpoint of further stabilizing the contact pressure, the pressure receiving portion 231A and the rotation stopping portion 202 may be provided at both ends and near the center of the frame 610 in the left-right direction. In addition, from the viewpoint of reducing the size of the developing unit 271 in the left-right direction, the pressure receiving portion 231A and the rotation stopping portion 202 may be disposed closer to the center of the frame 610 than the lift member 642 in the left-right direction, or may be disposed so as to overlap in the left-right direction within a range not protruding outside the lift member 642.

[0079] The first mixing chamber 210 and the second mixing chamber 220 of the developing unit 271 are disposed at the bottom on the lower side in the direction of gravity. The second top surface 242 is made up of a first wall surface 212 and a second wall surface 222 that form a top surface on the upper side in the direction of gravity, and a first top surface 241 and a second top surface 242 that form a top surface on the upper side in the direction of gravity. The first top surface 241 and the second top surface 242 are connected to the first top surface 241 via an intersection 242A that is the tip of the rear side of the second top surface 242. The intersection 242A has a shape that extends from the front side to the rear side on the second top surface 242, and is disposed so as to overlap with the first top surface 241 in the front-rear direction. In other words, the intersection 242A and the first top surface 241 are provided so as to intersect in the front-rear direction.

[0080] 19 includes a photosensitive unit 261 and a developing unit 271 that is detachable from the photosensitive unit 261. The photosensitive unit 261 includes a photosensitive drum 61, a frame 610 that supports the photosensitive drum 61, and a rotation stopper 202 that presses the developing unit 271 toward the photosensitive unit 261. The developing unit 271 includes a developing roller 71, a housing 251 in which a first stirring chamber 210 and a second stirring chamber 220 that accommodate toner are formed, and a pressure receiving portion 231A that receives pressure from the rotation stopper 202.

[0081] The housing 251 has an arc-shaped first wall surface 212 protruding toward the outside of the first stirring chamber 210, an arc-shaped second wall surface 222 protruding toward the outside of the second stirring chamber 220, a first top surface 241 provided on the upper side in the direction of gravity, a second top surface 242 provided further upward in the direction of gravity than the first top surface 241 and arranged so as to overlap a part of the first top surface 241 when viewed from above, and an intersection portion 242A (connection portion) connecting the first top surface 241 and the second top surface 242. The intersection portion 242A has an opposing surface 242B opposing the first top surface 241 on the lower side of the second top surface 242. As a result, as shown in FIG. 19, by inserting a finger into the overlapping portion between the first top surface 241 and the second top surface 242 when viewed from above, and grasping the second top surface 242 from above while supporting the opposing surface 242B from below, this portion can be used as a handle when attaching or detaching the developing unit 271.

[0082] Moreover, the rotation stopper 202 according to the second embodiment has a rotation stopper roller 202A that supports the developing unit 271 when the developing unit 271 is attached to the photoconductor unit 261. When viewed from the direction along the rotation axis of the developing roller 71, the rotation stopper roller 202A is disposed in the first recess 231, as in the first embodiment. This allows the rotation stopper 202 to be disposed in the first recess 231, which would normally be dead space, and therefore makes it possible to reduce the size of the developing unit 271. In other words, the capacity of the space that contains the toner can be increased without making the developing unit 271 larger.

[0083] <Actions and Effects of Example 2> In this embodiment, by providing the rotation stopper 202 in the first recess 231, the pressure receiving portion 231A receives a pressing force of a rotation stopper abutment force 202F from the rotation stopper 202. Compared to a configuration in which the portion of either the first wall surface 212 or the second wall surface 222 that is lower in the gravity direction than the first recess 231 is supported by the rotation stopper 202, the process cartridge 5 according to the second embodiment can save space in the vertical direction.

[0084] In this embodiment, the horizontal component 202H of the rotation stopper 202 applied to the developing unit 271 faces in the same direction as the pressing force horizontal component 201H, that is, in the direction from the front to the rear. Therefore, the horizontal component 202H adds a biasing force of the developing roller 71 to the photosensitive drum 61, so that the contact state of the developing roller 71 with the photosensitive drum 61 can be further stabilized.

[0085] In addition, since the contact means of the developing roller 71 against the photosensitive drum 61 is distributed between the pressing member 201 and the rotation stopper 202, the compression spring force of the pressing member 201 can be kept low. By suppressing the compression spring force of the pressing member 201, the process cartridge 5 can be easily used even when the process cartridge 5 is left unused for a long period of time. Since creep deformation of the frame 610 caused by the deformation can be suppressed, it is possible to reduce the strength required for the frame 610. Therefore, it is possible to reduce costs by making the frame 610 thinner, for example.

[0086] In this embodiment, the intersection 242A intersects with the stirring chamber first top surface 241 in the front-rear direction. Therefore, when attaching or detaching the developing unit 271 to or from the photoconductor unit 261, the intersection 242A can be used as a handle of the developing unit 271 to be held by hooking fingers. Therefore, compared to a configuration in which the handle of the developing unit 271 is provided forward of the second wall surface 222, it is possible to save space in the horizontal direction (front-rear direction). Furthermore, compared to a configuration in which the handle of the developing unit 271 is provided forward of the second wall surface 222, it is possible to hold a position closer to the center of gravity 251G in the horizontal direction (front-rear direction) of the developing unit 271. Therefore, it is possible to reduce the burden on the wrist when attaching or detaching the developing unit 271 to or from the photoconductor unit 261, that is, the moment load around the wrist accompanying holding the developing unit 271.

[0087] In this embodiment, since the first recess 231 is provided with the rotation stopper 202, the first recess 231 and the rotation stopper 202 can be used as a concave-convex shape for engagement to prevent erroneous installation between a plurality of process cartridges having different specifications such as life span and speed. Specifically, if the first recess 231 of the developing unit 271 is provided at a position different from the rotation stopper 202, either the first wall surface 212 or the second wall surface 222 will abut against the rotation stopper 202 when the developing unit 271 is installed in the photosensitive unit 261. In such a case, the developing unit 271 cannot be installed to the installation completion position as shown in FIG. 18(a), so that the user can recognize the erroneous installation of the developing unit 271.

[0088] [Example 3] Next, a third embodiment of the present invention will be described with reference to FIG. 20. In this embodiment, differences from the above-mentioned embodiment will be described in detail. Unless otherwise specified, the configuration is the same as in the above-mentioned embodiment, so that the same numbers are given to such parts and detailed description will be omitted. FIG. 20 is a top view illustrating the left-right positional relationship of the first stirring chamber 210 and the second stirring chamber 220 when the developing unit 272 is attached to the photoconductor unit 262 in the third embodiment. In order to show the internal structure of the first stirring chamber 210 and the second stirring chamber 220, the top surface 240 of the stirring chamber is omitted.

[0089] 20, the first stirring chamber 210 as the first transport chamber has a first stirring chamber longitudinal width 213H in the left-right direction from the left side wall 704 of the developing unit 272 to the first stirring chamber side wall 213. Similarly, the second stirring chamber 220 as the second transport chamber has a second stirring chamber longitudinal width 223H in the left-right direction from the left side wall 704 to the second stirring chamber side wall 223. The second stirring chamber longitudinal width 223H is longer than the first stirring chamber longitudinal width 213H.

[0090] At least a part of the pressing member 200 or the lift member 642 is disposed so as to overlap in the left-right direction between the first stirring chamber side wall 213 and the second stirring chamber side wall 223. In other words, the pressing member 200 and the lift member 642 are disposed in the left-right direction on a side farther from the left-right center of the developing unit 272 than the first stirring chamber side wall 213. In addition, at least a part of the pressing member 200 or the lift member 642 is disposed in the left-right direction on a side closer to the left-right center of the developing unit 272 than the second stirring chamber side wall 223.

[0091] The pressing member 200 or the lift member 642 is disposed rearward of the second stirring chamber 220 and forward of the developing roller 71 in the front-rear direction.

[0092] In this embodiment, the pressing member 200 is provided on the left side of the lift member 642. From the viewpoint of usability when removing the unit, it is also possible to reverse the left-right positional relationship, that is, to provide the pressing member 200 on the right side of the lift member 642. In this embodiment, the pressing member 200 and the lift member 642 are arranged so as to overlap at least partially between the first stirring chamber side wall 213 and the second stirring chamber side wall 223 in the left-right direction, but the pressing member 200 may be arranged in the first recess 231 described in the second embodiment.

[0093] 20 according to the third embodiment, similarly to the above-mentioned embodiments, the developing unit 272 according to the third embodiment shown in FIG. 20 has a first agitator 211 that transports toner, a second agitator 221 that transports toner, a first agitation chamber 210 that houses the first agitator 211, and a second agitation chamber 220 that houses the second agitator 221. The second agitation chamber 220 has a second agitation chamber longitudinal width 223H in the direction along the rotation axis of the developing roller that is larger than a first agitation chamber longitudinal width 213H of the first agitation chamber 210 in the direction along the rotation axis of the developing roller.

[0094] <Actions and Effects of Example 3> The lift member 642 is provided on a side farther from the left-right center of the developing unit 272 than the first mixing chamber sidewall 213 in the left-right direction, and is provided between the second mixing chamber 220 and the developing roller 71 in the front-rear direction. Therefore, since it can be seen from the direction of the top view shown in FIG. 20, that is, from the top surface side of the developing unit 272, it is possible to ensure visibility of the lift member 642 when removing the developing unit 272 from the photoconductor unit 262.

[0095] Since the second agitation chamber longitudinal width 223H is set to be longer than the first agitation chamber longitudinal width 213H, the volume of toner contained in the second agitation chamber 220 can be increased by an amount corresponding to the difference between the second agitation chamber longitudinal width 223H and the first agitation chamber longitudinal width 213H. This makes it possible to further extend the life of the developing unit 272.

[0096] [Example 4] Next, a fourth embodiment of the present invention will be described with reference to Figs. 21 to 24. In this embodiment, differences from the above-mentioned embodiment will be described in detail. Unless otherwise specified, the configuration is the same as in the above-mentioned embodiment, and therefore the same numbers are given to such parts, and detailed description will be omitted. Figs. 21 and 22 are a top view and a cross-sectional view for explaining the developer transport configuration when the developing unit 372 is attached to the photoconductor unit 362 in the fourth embodiment. In order to show the internal structure of the first stirring chamber 210 and the second stirring chamber 220, the top surface 240 of the stirring chamber is omitted.

[0097] 21 and 22, the first stirring chamber 210 is provided with a rotatable first agitator 311. The first agitator 311 has a first stirring rod 311S, a first rotating shaft 311A ​​extending in the left-right direction, a first stirring sheet 312 made of a flexible sheet member, and a plurality of stirring blades 313, and supplies toner to the supply roller 72 by rotating about the first rotating shaft 311A. In order to adjust the toner supply force, holes 312H are provided in the first stirring sheet 312 at a plurality of locations spaced apart along the length of the first stirring sheet 312.

[0098] The first stirring rod 311S is provided with stirring blades 313 in order to transport the toner in the first stirring chamber 210 to the central portion. The toner stored in the supply roller 72 is discharged again into the first stirring chamber 210 by rubbing against the developing roller 71. A part of the discharged toner is transported to both ends in the axial direction of the supply roller 72. In order to return the toner transported to both ends to the central portion in the left-right direction of the first stirring chamber 210, the above-mentioned stirring blades 313 are provided on the first stirring rod 311S.

[0099] A plurality of stirring blades 313 are provided on first stirring bar 311S at intervals along the left-right direction of first stirring bar 311S. In this embodiment, six stirring blades 313 are provided. The stirring blades 313 in this embodiment are semi-oval flat members, and are configured so that the normal line at the intersection point 311P with the first rotating shaft 311A ​​intersects with the first rotating shaft 311A ​​at an angle 313θ. The right three of the multiple stirring blades 313 are arranged so that the angle 313θ is counterclockwise with respect to the first rotating shaft 311A, and the left three are arranged so that the angle 313θ is clockwise with respect to the first rotating shaft 311A. That is, the six stirring blades 313 are arranged symmetrically. Therefore, as the first stirring rod 311S rotates, the toner at the left and right ends in the first stirring chamber 210 receives a conveying force from the stirring blades 313 toward the left and right center.

[0100] The second agitation chamber 220 is also provided with a rotatable second agitator 321. The second agitator 321 has a second rotation shaft 321A extending in the left-right direction and a second agitation sheet 322 made of a flexible sheet member, and conveys toner from the second agitation chamber 220 toward the second agitation chamber 220 by rotating about the second rotation shaft 321A. The second agitation sheet 322 has a linear notch 322C extending in a direction having a certain angle 322θ with the second rotation shaft 321A.

[0101] In this embodiment, six notches 322C are provided, and each notch 322C is located between intersection 311P of agitator blade 313 and first rotating shaft 311A ​​in the left-right direction. The amount of toner transported by the second agitator is less than the amount of toner transported by first agitator 311. Of the multiple notches 322C, the three on the right side are provided so that angle 322θ is counterclockwise with respect to second rotating shaft 321A, and the three on the left side are provided so that angle 322θ is clockwise with respect to second rotating shaft 321A. That is, the six notches 322C are provided symmetrically.

[0102] The impeller 313 shown in this embodiment is an example, and the shape and number of the impeller 313 can be freely determined from the viewpoint of adjusting the mixing performance. For example, the impeller 313 in this embodiment has a semi-oval flat plate shape, but it may have a spiral shape with a twist angle with respect to the first rotating shaft 311A, or a shape with unevenness on the side or face. In addition, from the viewpoint of changing the circulation performance for each position in the left-right direction, it is also possible for the multiple impellers 313 to have different shapes, sizes, thicknesses, and angles of the faces. In addition, the multiple impellers 313 do not necessarily have to be spaced apart at equal intervals, and the direction of the normal line of the face at each intersection 311P does not necessarily have to be the same.

[0103] In this embodiment, the shape of the notch 322C is a line having a certain angle 322θ with the second rotation axis 321A, but this certain angle 322θ may be any angle other than 0 degrees and 180 degrees, and the width of the line may be freely determined from the viewpoint of workability. The shape, number, and interval of the notch 322C shown in this embodiment are only examples, and these can be freely determined from the viewpoint of adjusting the conveying capacity. In addition, from the viewpoint of changing the conveying capacity according to the position in the left-right direction, it is also possible for the multiple notches 322C to have different shapes, sizes, and intervals.

[0104] Fig. 23 is a diagram showing examples of shapes that the notch on the stirring sheet according to the fourth embodiment can take. In the example shown in Fig. 23, the shape is a rectangle extending in a direction perpendicular to the second rotating shaft 321A, with a circle connected to the end of the rectangle (Fig. 23(a)), a shape in which multiple lines are connected at the end or in the middle of the line (Fig. 23(b), Fig. 23(c)), an arc shape (Fig. 23(d)), a triangular shape (Fig. 23(e)), etc. It is also possible to combine these shapes in one second stirring sheet 322 (Fig. 23(f)).

[0105] In addition, Fig. 24 is a diagram showing examples of shapes that the holes on the stirring sheet according to the fourth embodiment can have. As shown in Fig. 24, it is also possible to provide a second hole 322H on the surface of the second stirring sheet 322 instead of the notch 322C in this embodiment. In this case, the shape of the second hole 322H is The shape can be freely determined from the viewpoint of adjusting the conveying capacity. In the example shown in Fig. 24, the shapes include a rectangle (Fig. 24(a), Fig. 24(e)), an ellipse (Fig. 24(b)), a triangle (Fig. 24(c)), and a circle (Fig. 24(d)). The shape of the second hole 322H may be different in the left and right directions (Fig. 24(f)), and the number and intervals may be freely determined.

[0106] Thus, the developing unit 372 according to the fourth embodiment shown in FIG. 21 includes a first agitator 311 that conveys toner toward the developing roller, and a second agitator 321 that conveys toner toward the first agitator 311. The first agitator 311 includes a first rotating shaft 311A ​​and a plurality of stirring blades 313 that are inclined with respect to the axis of the first rotating shaft 311A. The second agitator 321 includes a second stirring sheet 322. The second stirring sheet 322 includes a plurality of notches 322C (slits) that are formed at an angle with respect to the second rotating shaft 321A. This allows the amount of toner conveyed by the first agitator 311 and the second agitator 321 to be appropriately adjusted.

[0107] The first agitator 311 has a plurality of stirring blades 313. At least a part of the notch 322C is located between two adjacent stirring blades 313 in the axial direction when viewed from a direction perpendicular to the first rotation shaft 311A. The notch 322C has a first end 322A located on the free end side of the second stirring sheet 322 and a second end 322B opposite to the first end 322A. The notch 322C extends from the second end 322B to the first end 322A from the center toward the outside in the direction along the second rotation shaft 321A of the second stirring sheet 322. This allows the toner in the first stirring chamber 210 and the second stirring chamber 220 to be transported so as to circulate.

[0108] 25 according to the fourth embodiment includes a rotatable first agitator 211 (first transport member) that transports the toner in the first stirring chamber 210 toward the developing roller 71, a rotatable second agitator 221 (second transport member) that transports the toner in the second stirring chamber 220 toward the first agitator 211, and a third agitator 501 (third transport member) that transports the toner in the third stirring chamber 503 toward the second agitator 221. The housing includes an arc-shaped first wall surface 212 that protrudes toward the outside of the first stirring chamber 210, an arc-shaped second wall surface 222 that protrudes toward the outside of the second stirring chamber 220, and an arc-shaped third wall surface 505 that protrudes toward the outside of the third stirring chamber 503.

[0109] The first agitator 211 is disposed above the first wall surface 212, the second agitator 221 is disposed above the second wall surface 222, and the third agitator 501 is disposed above the third wall surface 505. As shown in Fig. 25, when the developing unit 500 is viewed from a direction along the rotation axis of the first agitator 211, in a direction connecting the rotation center of the first agitator 211 and the rotation center of the second agitator 221, at least a part of the third wall surface 505 extends in a direction away from the photosensitive drum 61 from an end opposite to an end on one side where the photosensitive drum 61 is disposed.

[0110] In addition, the third agitator 501 is rotatable, and the center of rotation of the third agitator 501 may be disposed above the line L1 connecting the center of rotation of the first agitator 211 and the center of rotation of the second agitator 221 in the direction of gravity.

[0111] <Actions and Effects of Example 4> In this embodiment, the notches 322C of the second agitation sheet 322 are provided between a plurality of intersections 311P between the agitation blade 313 and the first rotating shaft 311A ​​in the left-right direction. Furthermore, the amount of toner transported by the second agitator 321 is less than the amount of toner transported by the first agitator 311. This makes it possible to prevent excessive toner supply to the agitation blade 313 provided on the first agitator 311 and suppress toner deterioration in the development chamber.

[0112] [Example 5] Next, a fifth embodiment of the present invention will be described with reference to Figs. 32, 33, and 34. In this embodiment, differences from the above-mentioned embodiment will be described in detail. Unless otherwise specified, the configuration is the same as in the above-mentioned embodiment, so that such parts are given the same numbers and detailed description will be omitted. Figs. 32 and 33 are cross-sectional views of the developing unit 470 attached to the photoconductor unit in the fifth embodiment. Fig. 34 is a top view for explaining the developer transport configuration when the developing unit is attached to the photoconductor unit.

[0113] The first agitator 311 has a first stirring bar 311S, a first rotating shaft 311A ​​extending in the left-right direction, a first stirring sheet 312 made of a flexible sheet member, and a plurality of stirring blades 313, and supplies toner to the supply roller 72 by rotating about the first rotating shaft 311A. The first stirring bar 311S is provided with the stirring blades 313 to transport the toner in the first stirring chamber 210 (first toner storage chamber) to the central portion. The toner stored in the supply roller 72 is discharged again into the first stirring chamber 210 by rubbing against the developing roller 71. A part of the discharged toner is transported to both ends of the axial direction of the supply roller 72.

[0114] The above-mentioned stirring blades 313 are provided on the first stirring rod 311S in order to return the toner transported to both ends to the left-right center of the first stirring chamber 210. Furthermore, the stirring blades 313 at both longitudinal ends reduce the toner pressure at both ends, so that by filling the gaps between the longitudinal ends of the developing roller 71 and the housing 700, it is possible to reduce toner leakage from toner seals (not shown) that prevent toner leakage.

[0115] A plurality of stirring blades 313 are provided at intervals along the left-right direction of first stirring rod 311S. In this embodiment, six stirring blades 313 are provided. The stirring blades 313 have a semi-oval flat plate shape, and have an angle 313θ at which a normal line at intersection 311P with first rotating shaft 311A ​​intersects with first rotating shaft 311A. In addition, second stirring chamber 220 (second toner storage chamber) is provided with a rotatable second agitator 321.

[0116] The second agitator 321 has a second stirring rod 321S, a second rotating shaft 321A extending in the left-right direction, and a second stirring sheet 322 made of a flexible sheet member, and rotates about the second rotating shaft 321A to transport toner from the second stirring chamber 220 toward the first stirring chamber 210. The amount of toner transported by the second agitator 321 is smaller than the amount of toner transported by the first agitator 311.

[0117] Further, the third stirring chamber 403 (third toner storage chamber) is provided with a rotatable third agitator 401. The third agitator 401 has a third stirring rod 401S, a third rotating shaft 401A extending in the left-right direction, and a third stirring sheet 402 made of a flexible sheet member, and conveys toner from the third stirring chamber 403 toward the second stirring chamber 220 by rotating about the third rotating shaft 401A. The amount of toner conveyed by the third agitator 401 is set to be less than the amount of toner conveyed by the second agitator 321. This makes it possible to prevent the second stirring chamber 220 and the first stirring chamber 210 from being excessively clogged with toner in the backward direction.

[0118] 32, the rotation center of the third agitator 401 is provided near the second line T302 in the vertical direction, that is, within the rotation radius of the tip of the third agitation sheet 402. Here, the second line T302 is perpendicular to the rotation axis direction (left-right direction) of the developing roller 71 and is a straight line connecting the rotation centers of the developing roller 71 and the first agitator 311. The second line T302 also passes through the second agitation chamber 220 and the third agitation chamber 403.

[0119] The center of rotation of the third agitator 401 is located near the second line T302 in the vertical direction. The second line T302 is inclined toward the horizontal line (front-rear direction) rather than the vertical line (vertical direction), so that the vertical drop between the first agitation chamber 210, the second agitation chamber 220, and the third agitation chamber 403 is kept low. Therefore, the vertical size (height) of the developing unit 470 can be reduced, and the vertical size (height) of the process cartridge 5 and the image forming apparatus 1 can be reduced.

[0120] In addition, since the toner drop (height) is kept low when the third agitator 401 transports the toner from the third mixing chamber 403 to the second mixing chamber 220, it is possible to prevent an increase in powder pressure due to the accumulation of toner in the vertical direction. Therefore, deterioration due to an increase in the powder pressure of the toner is suppressed, and it is possible to further extend the life of the developing unit 270.

[0121] As described above, the third agitator 401 is configured with the third rotating shaft 401A and the third agitation sheet 402, but is not necessarily limited to this configuration. For example, as shown in Fig. 33 and Fig. 34, the third agitator 450 may have a third agitation bar 451S, a plurality of agitation blades 452, and a third agitation sheet 455, and may transport toner from the third agitation chamber 403 toward the second agitation chamber 220 by rotating around the third rotating shaft 451A.

[0122] Third stirring bar 451S is provided with stirring blades 452 to transport toner in third stirring chamber 403 toward the outside in the axial direction of third stirring bar 451S. A plurality of stirring blades 452 are provided on third stirring bar 451S at intervals along the left-right direction of third stirring bar 451. In this embodiment, six stirring blades 452 are provided. In this embodiment, stirring blade 452 has a semi-oval flat plate shape and is configured to have angle 453θ at which a normal line at intersection 451P with third rotation shaft 451A intersects with third rotation shaft 451A.

[0123] When the first to third agitators rotate, the toner in the third stirring chamber 403 is transported to the outside in the axial direction of the third stirring rod 451S, and is transported from the third stirring chamber 403 toward the second stirring chamber 220 by the third stirring sheet 455. Furthermore, when the second agitator 321 rotates, the toner in the second stirring chamber 220 is transported from the second stirring chamber 220 toward the first stirring chamber 210. The first stirring rod 311S of the first agitator 311 is provided with stirring blades 313 to transport the toner in the first stirring chamber 210 to the center portion, so that the first, second, and third agitators cause the toner to circulate as indicated by arrows 480 and 481 in FIG. 34. This large toner circulation makes it possible to suppress the deterioration of the toner, and thus makes it possible to further extend the life of the developing unit 270.

[0124] The amount of toner transported by the third agitator 450 is set to be equal to or smaller than the amount of toner transported by the first agitator 311. This makes it possible to prevent excessive clogging of toner in the rear direction in the second agitation chamber 220 and the first agitation chamber 210. In this embodiment, the third agitator is configured to have multiple agitation blades, but the second agitator may be configured to have multiple agitation blades that transport toner toward the outside in the axial direction of the agitation rod, and the third agitator may simply have an agitation sheet fixed to the rotating shaft.

[0125] 34, in this embodiment, the lift member 642 and the like are not present around the third stirring chamber 403 located away from the developing roller. Therefore, a space is created in the axial direction of the stirring rod, and the side wall surface 490 in the left-right direction (axial direction of the third stirring rod 451S) of the third stirring chamber 403 can be provided on the left-right outer side than the side wall surface 491 in the left-right direction (axial direction of the second stirring rod 321S) of the second stirring chamber 220. This allows the toner container capacity to be increased, making it possible to further extend the life of the developing unit 270.

[0126] As described above, the developing unit 470 according to the fifth embodiment shown in FIG. 32 includes a developing roller 71, The toner cartridge has a housing 700 in which a first stirring chamber 210, a second stirring chamber 220 and a third stirring chamber 403 for accommodating toner are formed, a first agitator 311 that transports the toner in the housing 700 toward the developing roller 71, a second agitator 321 that transports the toner in the housing 700 toward the first agitator 311, and a third agitator 401 that transports the toner in the housing 700 toward the second agitator 321.

[0127] The housing 700 has an arc-shaped first wall surface 212 protruding toward the outside of the first stirring chamber 210, an arc-shaped second wall surface 222 protruding toward the outside of the second stirring chamber 220, and an arc-shaped third wall surface 505 protruding toward the outside of the third stirring chamber 403. The first agitator 311 is disposed above the first wall surface 212, the second agitator 321 is disposed above the second wall surface 222, and the third agitator 401 is disposed above the third wall surface 505.

[0128] 34, the first agitator 211 includes a first rotating shaft 311A ​​and a plurality of stirring blades 313 fixed to the first rotating shaft 311A. The stirring blades 313 are disposed at an angle to the axis of the first rotating shaft 311A ​​so that a force for transporting toner is generated inward in the axial direction of the first rotating shaft 311A ​​when the first rotating shaft 311A ​​rotates.

[0129] 33 and 34 includes a third rotating shaft 451A and a plurality of agitating blades 452 fixed to the third rotating shaft 451A. The agitating blades 452 are disposed at an angle with respect to the axis of the third rotating shaft 451A so that a force is generated to transport the toner outward in the axial direction of the third rotating shaft 451A when the third rotating shaft 451A rotates. The agitating blades 313 and 452 may be, for example, in a shape having a helical surface or in a flat plate shape.

[0130] 33 and 34, the developing unit 470 has a first stirring chamber 210 that houses the first agitator 311, a second stirring chamber 220 that houses the second agitator 321, and a third stirring chamber 403 that houses the third agitator 450. The width of the third stirring chamber 403 as the third transport chamber in the direction along the second rotation shaft 321A of the second agitator 321 is larger than the width of the second stirring chamber 220 as the second transport chamber in the direction along the rotation shaft of the second agitator 321.

[0131] <Actions and Effects of Example 5> By providing the third agitator 401 in the third stirring chamber 403, the toner storage chamber can be increased in capacity. In addition, since the rotation center of the third agitator 401 is provided in the vicinity of the second line T302 in the vertical direction, that is, within the rotation radius of the tip of the third stirring sheet 402, the vertical (height) size of the developing unit 270 can be reduced. In addition, the stirring blade 313 of the first agitator 311 reduces the toner pressure at both ends, so that toner leakage from the toner seal portion at the end of the developing roller 71 can be prevented. In addition, since the third stirring rod 451S has the stirring blade 452 for conveying the toner toward the outside in the axial direction, it is possible to suppress the deterioration of the toner, and it is possible to further extend the life of the developing unit 270. In addition, since the side wall surface of the third stirring chamber 403 can be made to be on the outside in the left-right direction, the toner container capacity can be increased.

[0132] [Example 6] Next, a sixth embodiment of the present invention will be described with reference to Figures 25 to 31. In this embodiment, differences from the above-mentioned embodiments will be described in detail. Unless otherwise specified, the same components as those in the above-mentioned embodiments are given the same numbers and detailed descriptions will be omitted.

[0133] 25 and 29 show the configuration of the developing unit 500 and the photoconductor unit 260 in the sixth embodiment. 26(a), 27(a) and 28 are sectional views of the developing unit 500 attached to the photoconductor unit 260 when it is attached to the apparatus main body 2. FIGS. 26(b) and 27(b) are perspective views of the developing unit 500 attached to the photoconductor unit 260 as viewed from the cartridge door 520 side after it has been attached to the apparatus main body 2. FIG. 30 is a perspective view of the developing unit 500 attached to the photoconductor unit 260. FIG. 31 is a sectional view of the developing unit 500.

[0134] As shown in FIG. 25, the developing unit 500 is provided with a third agitator 501 in addition to the configuration of the developing unit 270 described in the first embodiment. The third agitator 501 is disposed in a third agitating chamber 503 provided in front of the second agitating chamber 220. The third agitating chamber 503 is a space for accommodating toner, which is formed by an agitating chamber third top surface 504 provided above the third agitator 501 in the direction of gravity, and a third wall surface 505 provided below the third agitator 501 in the direction of gravity. The third wall surface 505 is a convex wall surface that protrudes downward in the direction of gravity relative to the third agitator 501. A third recess 506 is formed at the boundary between the second wall surface 222 and the third wall surface 505 in the front-rear direction, and the second wall surface 222 and the third wall surface 505 are connected via the third recess 506.

[0135] In this embodiment, the process cartridge is configured so that when the developing unit 500 is attached to the photosensitive unit 260 , the third stirring chamber 503 of the developing unit 500 protrudes forward from the frame 610 of the photosensitive unit 260 .

[0136] Further, the rotation center of the third agitator 501 is disposed above a straight line L1 that connects the rotation center of the first agitator 211 and the rotation center of the second agitator 221.

[0137] 26(a), the developing unit 500 is attached to and detached from the apparatus main body while being attached to the photosensitive unit 260. At this time, a first engagement portion 507 is provided on the lower side in the gravity direction of the third wall surface 505 as an uneven shape for engagement to prevent erroneous attachment between the main body and a plurality of process cartridges having different specifications such as life span and speed. A second engagement portion 508 is also provided in the apparatus main body 2 as an uneven shape corresponding to this first engagement portion 507.

[0138] As shown in FIG. 26(b), when a compatible (matching specifications) developing unit 500 is attached to the device body 2, the uneven shapes provided on the first engagement portion 507 and the second engagement portion 508 do not come into contact with each other, and the developing unit 500 can be attached to the device body 2. However, as shown in FIG. 27(b), when an incompatible (different specifications) developing unit 500 is attached to the device body 2, the uneven shapes provided on the first engagement portion 507 and the second engagement portion 508 interfere with each other. In that case, as shown in FIG. 27(a), the developing unit 500 cannot be attached to the device body 2 to the complete attachment position.

[0139] Next, as shown in FIG. 28, the photoconductor unit 260 is provided with the photoconductor drum 61, a frame 610, and a pressing member 509. The pressing member 509 is provided behind the third stirring chamber 503 of the developing unit 500. When the developing unit 500 is attached to the photoconductor unit 260, the pressing member 509 presses the developing unit 500 in the direction of the arrow 201F, and presses the developing roller 71 provided in the developing unit 500 toward the photoconductor drum 61. The third recess 506 may be provided with the rotation stop roller portion 202 described above. The rotation stop roller portion 202 may be provided in the first recess 231 instead of the third recess 506. Furthermore, the developing unit 500 may be provided with a roller receiving portion 514 having a surface parallel to the direction of the arrow 201F at a position where the developing unit 500 comes into contact with the rotation stop roller portion 202.

[0140] As shown in FIG. 29, the photoconductor unit 260 is provided with the photoconductor drum 61, a frame 610, and a pressing member 509. The pressing member 509 is provided behind the second stirring chamber 220 of the developing unit 500. When the developing unit 500 is attached to the photoconductor unit 260, the pressing member 509 presses the developing unit 500 in the direction of the arrow 201F, and presses the developing roller 71 provided in the developing unit 500 toward the photoconductor drum 61. The pressing member 509 may be provided in the first recess 231. Furthermore, a roller receiving portion 514 with which the rotation stop roller portion 202 comes into contact may be provided in the third recess 506. The roller receiving portion 514 may have a surface parallel to the direction of the arrow 201F.

[0141] 30, a handle 510 is disposed on the upper side in the direction of gravity of the second stirring chamber 220. The handle 510 is rotatably fixed to a handle support portion 511 provided on the second top surface 242 of the stirring chamber.

[0142] A new product detection mechanism (see FIG. 8) using the above-mentioned detection member 81 and detection protrusion 83 may be provided on a surface including the cross section of the third mixing chamber 503 of the developing unit 500.

[0143] 31, the developing unit 500 is provided with a first filling port 512 and a second filling port 513. The first filling port 512 is provided between the first agitator 211 and the second agitator 221, and the second filling port 513 is provided between the second agitator 221 and the third agitator 501. Furthermore, as a sealing means for the first filling port 512 and the second filling port 513, they may be sealed with a sealing member having a shaft portion that rotatably supports an idler gear (not shown) for transmitting drive to the first agitator gear 713, the second agitator gear 714, and the third agitator gear (not shown) shown in FIG.

[0144] 27 is configured so that the process cartridge can be detachably attached to the apparatus main body 2 of the image forming apparatus according to the sixth embodiment. The third wall surface 505 of the developing unit 500 may have a first engaging portion 507 that can engage with a second engaging portion 508 (main body engaging portion) of the apparatus main body 2.

[0145] Further, the photoconductor unit 260 according to the sixth embodiment has a pressing member 509. The developing unit 500 has a pressure receiving portion pressed by the pressing member 509. When viewed from the direction along the rotation axis of the developing roller 71, at least a part of the pressure receiving portion 514 is arranged in a third recess 506 surrounded by a tangent line contacting the second wall surface 222 and the third wall surface 505, the second wall surface 222, and the third wall surface 505. Also, as shown in FIG. 29, at least a part of the pressure receiving portion may be arranged in the first recess 231.

[0146] <Actions and Effects of Example 6> In this embodiment, when the developing unit 500 is attached to the photoconductor unit 260, the third stirring chamber 503 of the developing unit 500 protrudes forward relative to the frame 610 of the photoconductor unit 260. In this configuration, the support structure of the developing unit 500 relative to the photoconductor unit 260 is made common to the developing unit 270. This makes it possible to attach a plurality of developing units with different life spans (toner capacities) without changing the photoconductor unit 260. Therefore, the number of types of photoconductor units to be incorporated when manufacturing a process cartridge is reduced. As a result, the number of molding dies required for each type of photoconductor unit can be reduced. In addition, since the assembly device only needs to be compatible with a relatively small number of types of photoconductor units, the manufacturing cost can be reduced by simplifying the assembly device.

[0147] In this embodiment, the rotation center of the third agitator 501 is disposed above the straight line L1 connecting the rotation center of the first agitator 211 and the rotation center of the second agitator 221. Therefore, the toner is transferred from the third agitator 501 to the second agitator 221 by gravity. This allows the toner to be transported. It is therefore possible to eliminate the third recess 506 and connect the third wall surface 505 and the second wall surface 222 with a slope that slopes downward in the direction of gravity from the third wall surface 505 toward the second wall surface 222, and transport the toner by sliding it along the slope. Also, by eliminating the third recess 506, it is possible to increase the amount of toner to be filled.

[0148] 28, a first engagement portion 507 provided on the developing unit 500 and a second engagement portion 508 provided on the device main body 2 make it possible to determine whether a combination of the device main body 2 and the developing unit 500 is compatible. An example of when compatibility is required is when the variety of products is increased by changing the toner, resulting in multiple combinations of the main device 2 and the developing unit 500. In that case, if a developing unit 500 that is not compatible with the main device 2 is attached, there is a risk that the main device 2 will break down.

[0149] In order to prevent such a situation, when the developing unit is attached to the apparatus main body 2, the first engagement portion 507 and the second engagement portion 508 interfere with each other, making it impossible to attach the developing unit 500 to the main body 2. In this embodiment, the first engagement portion 507 is provided on the developing unit 500 instead of the photoconductor unit 260, so that the photoconductor unit 260 can be made common even when multiple developing units with different specifications are provided as products. In this embodiment, the compatibility is achieved by the concave-convex relationship between the first engagement portion 507 and the second engagement portion 508, but the means for achieving the compatibility need not be limited to this, and various means such as positional relationship and size relationship are possible.

[0150] In addition, in this embodiment, the pressing member 509 is disposed in the space formed by the frame 610 of the photosensitive unit 260 and the third recess 506 or the first recess 231 of the developing unit 500 without any waste, so that the developing roller 71 can be pressed against the photosensitive drum 61 without affecting the size of the device main body 2. In addition, based on the same technical idea as above, the rotation stop roller portion 202 is disposed in the space formed by the frame 610 and the stirring chamber second recess 232 or the first recess 231, so that the posture of the developing unit 500 can be stabilized. In addition, in this embodiment, the developing roller 71 can be stably pressed against the photosensitive drum 61. The number of the pressing member 509 and the rotation stop roller portion 202 does not need to be limited to one.

[0151] Furthermore, by arranging the handle 510 on the upper side in the direction of gravity of the second mixing chamber 220 close to the center of gravity 500G of the developing unit 500, the load imposed on the user when gripping the developing unit 500 can be reduced.

[0152] In this embodiment, since the third recess 506 is provided with the pressing member 509, the third recess 506 and the pressing member 509 can be used as a concave-convex shape for engagement to prevent erroneous installation between a plurality of process cartridges having different specifications such as life span and speed. Specifically, if the third recess 506 of the developing unit 500 is provided at a position different from the pressing member 509, when the developing unit 500 is installed in the photosensitive unit 260, either the second wall surface 222 or the third wall surface 505 hits the pressing member 509. As a result, the developing unit 500 cannot be installed to the installation completion position as shown in FIG. 18. By configuring the process cartridge as in this embodiment, it is possible to make the user aware of the erroneous installation of the process cartridge in the apparatus main body.

[0153] The configurations described in the above embodiments can be appropriately combined within the scope of no inconsistency. [Explanation of symbols]

[0154] 5...process cartridge, 61...photosensitive drum, 71...developing roller, 200...pressure portion member, 212...first wall surface, 222...second wall surface, 231...first recess, 250...casing, 260...photoconductor unit, 270...developing unit, 610...frame

Claims

1. A cartridge configured to be detachably attached to the main body of an image forming apparatus, a drum unit having a rotatable photosensitive drum, a pressing portion, and a frame; a developing unit detachably attached to the drum unit, the developing unit having a developing roller rotatable around a first rotation axis, a toner storage section for storing toner, an agitating member disposed in the toner storage section and agitating the toner, the agitating member rotatable around a second rotation axis extending in the first rotation axis direction which is a direction along the first rotation axis, a handle portion, and a pressed portion pressed by the pressing portion of the drum unit, the pressed portion being pressed in a direction in which the developing roller approaches the photosensitive drum; When the cartridge faces a mounting direction in which the cartridge is mounted to the main assembly of the apparatus, as viewed from the first rotation axis direction of the developing roller, i) the grip portion, the pressed portion, the stirring member, the developing roller, and the photosensitive drum are arranged in this order in the mounting direction; ii) the pressed portion is pressed by the pressing portion at a position between an end portion where a side surface of the toner accommodating portion is formed and a center portion of the toner accommodating portion in the first rotation axis direction, iii) a wall surface portion constituting a part of the toner storage portion is disposed between the handle portion and the pressed portion in the mounting direction, and the wall surface portion extends downward to the pressed portion in the mounting direction; iv) the handle portion extends above the top of the frame of the drum unit; A cartridge characterized by being configured as follows.

2. A cartridge as described in Claim 1, characterized in that the stirring member includes an stirring sheet, and the stirring sheet has a plurality of holes formed along a second rotational axis direction, which is a direction along the second rotational axis of the stirring member.

3. A cartridge as described in Claim 2, characterized in that the stirring member includes a stirring rod that can rotate around the second rotation axis, the stirring sheet is attached to the stirring rod and configured to rotate as the stirring rod rotates, and the stirring member has a protrusion formed to protrude from the stirring rod.

4. A cartridge as described in Claim 3, characterized in that the protrusion further has a gap portion for allowing toner to pass through.

5. A cartridge as described in claim 2, characterized in that each of the multiple holes has a square shape.

6. A cartridge as described in Claim 5, characterized in that the square is a rectangle.

7. A cartridge as described in Claim 6, characterized in that the long side of the rectangle extends in a direction perpendicular to the second rotation axis of the stirring member.

8. The cartridge described in Claim 1, characterized in that the developing unit has an engaging portion that engages with an engaging portion in the drum unit that protrudes in the first rotational axis direction of the developing roller, and when the cartridge is facing the mounting direction and viewed from the first rotational axis direction of the developing roller, the engaging portion is positioned below the position of the handle portion.

9. A cartridge as described in claim 1, characterized in that when the cartridge is facing the mounting direction, in a cross section perpendicular to the first rotation axis, if a line that passes through the point where the pressing portion contacts the pressed portion and is parallel to the pressing direction of the pressing portion is defined as a first line, the first line passes through the toner storage portion.

10. A cartridge as described in Claim 9, characterized in that the developing roller is positioned above the first line.

11. A cartridge as described in Claim 9, characterized in that the photosensitive drum is positioned above the first line.

12. A cartridge as described in Claim 1, characterized in that the pressed portion is positioned inside the end of the developing roller in the first rotational axis direction.

13. A cartridge as described in claim 1, characterized in that the pressed portion is positioned inside the end of the photosensitive drum in the first rotational axis direction.

14. A cartridge as described in Claim 1, characterized in that the developing unit further has a supply roller that contacts the developing roller to supply toner, and the pressed portion is positioned inside the end of the supply roller in the direction of the first rotation axis.

Images