Foreign matter collection device, process cartridge, and image forming apparatus

Abstract

To provide a technology that can improve the ability to accommodate a foreign substance in a process cartridge.SOLUTION: A foreign substance recovery device has a frame body, a photoreceptor drum 61, a cleaning roller 210 that recovers a foreign substance from a surface of the photoreceptor drum 61, a recovery roller 220 that further recovers the foreign substance recovered by the cleaning roller 210 from the cleaning roller 210, and a scraping member 230 for scraping off the foreign substance from the recovery roller 220. A foreign substance recovery unit 241 included in the frame body has a first inside bottom face 240a that is located below the scraping member in the gravity direction in a usage posture, an outer peripheral bottom face 242a that is located below the first inside bottom face 240a, and a connection surface 240c that intersects the first inside bottom face 240a and the outer peripheral bottom face 242a and connects the first inside bottom face 240a with the outer peripheral bottom face 242a.SELECTED DRAWING: Figure 19

Description

[Technical Field]

[0001] The present invention relates to a cartridge for a photosensitive unit, a developing unit, or the like that 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 then transferred to a sheet serving as a recording material, thereby forming an image on the recording material. To facilitate maintenance, laser beam printers generally employ a system in which some components of the image forming apparatus are housed in a cartridge, and the cartridge is removed from the main body of the apparatus for maintenance or replacement. Patent Document 1 discloses a process cartridge in which a developing unit containing toner can be detachably attached to a photosensitive unit having a photosensitive drum. [Prior art documents] [Patent documents]

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

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

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide a technique capable of improving the ability of a process cartridge to contain foreign matter. [Means for solving the problem]

[0006] In order to achieve the above object, the foreign body recovery device of the present invention comprises: A frame body, an image carrier rotatably supported by the frame and carrying a developer image; a first recovery member that is rotatably supported by the frame and that recovers foreign matter from the surface of the image carrier by rotating while being in contact with the surface of the image carrier; a second recovery member that is rotatably supported by the frame and rotates while in contact with a surface of the first recovery member, thereby recovering the foreign matter recovered in the first recovery member from the first recovery member; a scraping member provided on the frame so as to be able to slide against the rotating second collection member, for scraping the foreign matter from the second collection member; a third recovery member capable of contacting the second recovery member; a third retrieval member having a shaft portion and a seat portion attached to the shaft portion; and The third recovery member is controlled to come into contact with the outer circumferential surface of the second recovery member during a rotational movement of the second recovery member. 、 The outer peripheral surface of the seat portion is capable of contacting the second recovery member. It is characterized by: [Effects of the Invention]

[0011] According to the present invention, the ability of the process cartridge to contain foreign matter can be improved. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view of an image forming apparatus according to a first embodiment; [Figure 2] 1 is a cross-sectional view of a developing unit according to a first embodiment; [Figure 3] FIG. 1 is a perspective view of a developing unit according to a first embodiment; [Figure 4] FIG. 1 is an exploded perspective view of a developing unit according to a first embodiment; [Figure 5] 1 is a cross-sectional view of a process cartridge according to a first embodiment; [Figure 6] FIG. 1 is a top view of a development unit according to a first embodiment; [Figure 7]FIG. 1 is a perspective view of a process cartridge according to a first embodiment; [Figure 8] 1 is an explanatory diagram of a detection member according to a first embodiment; [Figure 9] FIG. 1 is a perspective view of a developing unit according to a first embodiment; [Figure 10] FIG. 1 is a perspective view of a process cartridge according to a first embodiment; [Figure 11] FIG. 1 is a partial perspective view of a photosensitive unit according to a first embodiment; [Figure 12] FIG. 1 is a perspective view of a developing unit and a photosensitive unit according to a first embodiment; [Figure 13] 1 is a top view of a developing unit and a photosensitive unit according to a first embodiment; [Figure 14] FIG. 1 is a perspective view of a process cartridge according to a first embodiment; [Figure 15] FIG. 1 is a partial perspective view of a developing unit and a lift member according to a first embodiment; [Figure 16] FIG. 1 is a diagram showing the positional relationship between a lift member and a pressing member according to the first embodiment; [Figure 17] FIG. 10 is a diagram illustrating the removal of a developing unit according to the first embodiment. [Figure 18] 1 is a cross-sectional view of a photosensitive unit and a cleaning unit according to a first embodiment; [Figure 19] FIG. 1 is a diagram showing the size of each part in the left-right direction according to the first embodiment; [Figure 20] FIG. 1 is a diagram showing the size of each part in the left-right direction according to the first embodiment; [Figure 21] 10 is a cross-sectional view showing another example of the foreign matter collecting recess according to the first embodiment; FIG. [Figure 22] 1 is a cross-sectional view showing a foreign matter collection section and a foreign matter collection recess according to a first embodiment; [Figure 23] 10 is a cross-sectional view showing a foreign matter transport member according to a second embodiment; FIG. [Figure 24] 10 is a cross-sectional view showing a collection and transport sheet according to a third embodiment; [Figure 25] FIG. 10 is a diagram illustrating the rotation of a cleaning roller and a collection roller according to a fourth embodiment. [Figure 26] 10 is a cross-sectional view showing another example of a scraping member according to the fourth embodiment; DETAILED DESCRIPTION OF THE INVENTION

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

[0014] [First embodiment] First, an image forming apparatus and a process cartridge according to a first embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 2 is a cross-sectional view of the image forming apparatus 1.

[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 bottom (bottom) side as the "lower." Furthermore, 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 directions of the process cartridge 5 are also defined in the same manner as those of the image forming apparatus 1, assuming that the process cartridge 5 is in the same position as when it is installed in the image forming apparatus 1. The directions in each drawing are defined by the arrows shown in the drawing.

[0016] The front-to-rear, up-down, and left-to-right directions indicated by these arrows are perpendicular to one another. These directions are the same in all drawings. The up-to-down direction is parallel to the vertical direction, and the left-to-right and front-to-rear directions are parallel to the horizontal direction. The left-to-right directions are parallel to the rotational axis of the photosensitive drum 61 and the rotational axis of the developing roller 71, respectively. The developing unit 7 mounted integrally on the photosensitive unit 6 is referred to as the process cartridge 5. This process cartridge 5 is inserted in the direction of arrow S1 in the figure when mounted into the apparatus main body 2 (mounting direction), and is removed in the direction of arrow S2 in the figure.

[0017] <Overall configuration of image forming apparatus> FIG. 1 is a cross-sectional view of an image forming apparatus 1 equipped with a process cartridge 5. As shown in FIG. 1, the image forming apparatus 1 mainly comprises a paper feed unit 3 for supplying 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 unit 3 is provided in the lower part of the apparatus main body 2, and mainly comprises a paper feed tray 31 and a paper feed mechanism 32. The paper S stored in the paper feed tray 31 is supplied by the paper feed mechanism 32 toward the process cartridge 5 (between the photosensitive drum 61 and the transfer roller 63).

[0018] The exposure device 4 is disposed in the upper part of the device main body 2, and includes a laser emitting unit (not shown), a polygon mirror (shown without reference numerals), a lens, a reflecting mirror, etc. In the exposure device 4, the laser light based on image data emitted from the laser emitting unit is scanned at high speed over the surface of the photosensitive drum 61, thereby exposing the surface of the photosensitive drum 61.

[0019] The process cartridge 5 is disposed below the exposure device 4. It is configured to be inserted into the device body 2 in the direction of arrow S1 into a storage section 23 of the device body 2 through an opening that is created when a door (opening / closing member) 21 provided on the device body 2 is opened (shown by a two-dot chain line in FIG. 1), and then attached to the device body 2. When removing the process cartridge 5 from the device body 2, the process cartridge 5 is moved in the direction of arrow S2 and removed. In this way, the process cartridge 5 is configured to be detachable from the device body 2 of the image forming apparatus 1.

[0020] 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 roller 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 includes 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.

[0021] <Image formation process> Next, an image forming process using this process cartridge 5 will be described. The photosensitive drum 61 is rotated during the image forming process. The surface of the photosensitive drum 61 is uniformly charged by the electrostatic roller 62, and then exposed to laser light corresponding to the image data emitted from the exposure device 4, thereby forming an electrostatic latent image corresponding to the image data on the photosensitive drum 61.

[0022] Meanwhile, 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 then 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 constant thickness. In this way, the developing roller 71 functions as a developer carrier that carries the toner, which is the developer.

[0023] 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, making it 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 (developer image) on the photosensitive drum 61 is transferred onto the paper S by the transfer roller 63, which is a transfer member. At this time, the untransferred toner remaining on the photosensitive drum 61 is collected by the developing roller 71 and returned to the developing unit 7.

[0024] The fixing device 8 is disposed behind the process cartridge 5, and mainly includes fixing members, 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, and at that time, 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. After passing through the fixing device 8, the paper S is discharged onto the paper output tray 22.

[0025] <Process cartridge configuration> Next, we will explain each unit of the process cartridge 5. As mentioned above, the process cartridge 5 includes the photosensitive unit 6 and the developing unit 7 that is detachable from the photosensitive unit 6.

[0026] <Configuration of the development unit> First, the configuration of the developing unit 7 will be described. FIG. 2 is a cross-sectional view of the developing unit 7, 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, the cross section being parallel to the up-down direction and the front-rear direction. FIG. 6 is a top view of the developing unit 7, showing the state in which the top surface of the housing 700 and the side holder 719 have been removed for ease of explanation.

[0027] 2, the developing unit 7 has a grip 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 rotational axis of the developing roller 71 referred to as the axial direction.

[0028] 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 rotatably supported at their respective ends on a left side wall 704 and a right side wall 705 of the housing 700. To the left of the left side wall 704 of the housing 700, there are provided 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. 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. The first agitator gear 713 is fixed to the end of the stirring rod 78A (see FIG. 5) of the first agitator 75A, and the second agitator gear 714 is fixed to the end of the stirring rod 78B (see FIG. 5) of the second agitator 75B. It is fixed to the end of the

[0029] 3, the developing unit 7 is provided with a first electrical contact 720A that is electrically connected to the developing roller 71 and through which a voltage is applied to the developing roller 71, and a second contact 720B that is electrically connected to the supply roller 72 and through which a voltage is applied to the supply roller 72. These electrical contacts come into contact with a power supply contact (not shown) that is provided in the apparatus main body 2, thereby supplying power to the developing roller 71 and the supply roller 72.

[0030] 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.

[0031] 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, and the developing roller 71 can be rotated from a gear provided on the circumferential surface of the developing coupling 710 via the developing roller gear 711, and the supply roller 72 can be rotated via the supply roller gear 712. The developing drive transmission member is configured to transmit a driving force to the developing coupling 710 while allowing for positional deviation of the developing coupling 710 within a predetermined range. Axial movement of the developing coupling 710, the developing roller gear 711, and the supply roller gear 712 is restricted by a side holder 719 attached to the housing 700.

[0032] 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.

[0033] The second agitator 75B supplies the toner in the toner storage section 74 to the first agitator 75A. The toner near the first agitator 75A in the toner storage section 74 is agitated by the first agitator 75A, then supplied to the supply roller 72, and further supplied to the developing roller 71 by the supply roller 72.

[0034] 4 and 7, a detection unit 80 is provided at the left end of the developing unit 7. The detection unit 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.

[0035] The operation of the detection member 81 will be explained using 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.

[0036] 8(a) shows the developing unit 7 in an unused state. The detection protrusion 83 is located on the upper front side 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 developing coupling 710 from the developing drive transmission member of the apparatus main body 2. At this time, the detection gear 82 is engaged with the second agitator gear 714, so the detection member 81 rotates in the direction of arrow R4 in the figure.

[0037] 8(b) shows the state after the detection member 81 has rotated. Because 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 positioned above and rearward of the detection member 81. By detecting the position of the detection protrusion 83 of this detection member 81 with a detection mechanism (not shown) provided in the apparatus main body 2, it can be determined whether the development unit 7 is unused or has already been used.

[0038] 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 main body 2, and communicates between the memory chip and the device main body 2.

[0039] <Photoconductor unit configuration and development unit support> Next, the detailed configuration of the photosensitive unit 6 will be described. Figure 10 is a perspective view of the process cartridge 5. Figure 11(a) is a partial perspective view of the photosensitive unit 6, and Figure 11(b) is a cross-sectional view taken along the line BB in Figure 11(a). Figure 12 is a perspective view of the developing unit 7 and the photosensitive unit 6. Figure 13 is a top view showing the left-right positioning relationship between the photosensitive unit 6, the developing unit 7, and the developing roller 71. Figure 14(a) is a perspective view of the process cartridge 5 seen from below, and Figure 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, Figure 14(b) only shows the positioning protrusion 86 and the marking 85 of the developing unit 7.

[0040] As shown in Fig. 10, the photosensitive unit 6 mainly includes a frame 610 having a pair of left and right walls 611 and 612, and a photosensitive 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) into which the developing unit 7 can be mounted, a gripping portion 617 with which the user grips the photosensitive 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 lifts 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 and right walls 611 and 612 in the left-right direction.

[0041] 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).

[0042] The lifespan 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 lifespan of the photosensitive unit 6, which is determined by the thickness of the photosensitive layer on 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, open the door 21, remove the process cartridge 5 from inside the apparatus main body 2, remove the developing unit 7 that has reached the end of its life from the photosensitive unit 6, and attach another developing unit 7 to the photosensitive unit 6 as shown in the attachment direction AD in Figure 12. Thereafter, attach the photosensitive unit 6 with the developing unit 7 attached to it to the apparatus main body 2 as a process cartridge 5.

[0043] 7, 10, and 12, receiving portions 641 for receiving the rotation bearing members 746A and 746B of the developing roller 71 are 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 portions 641 are generally U-shaped recesses with an open front when viewed from the left, and the rotation shaft 746 of the developing roller 71 is inserted therein during the process of mounting the developing unit 7 to the photosensitive unit 6. The receiving portions 641 support the developing unit 7 on the photosensitive unit 6, while guiding movement of the developing unit 7 in the mounting direction AD shown in FIG.

[0044] 13, protrusions 643 are provided on both left and right ends of the bottom surface 613 of the frame 610, protruding upward. These protrusions 643 come into contact with 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 it can move.

[0045] As shown in FIG. 12 , the photosensitive unit 6 has a positioning hole 68 and a contact opening 69 provided in a frame 610, which are provided at one end side of the rotation axis direction (left-right direction) of the photosensitive drum 61. Here, "one end side" refers to the same side of the line dividing the photosensitive drum 61 in the left-right direction. When the developing unit 7 is installed in the photosensitive unit 6, as shown in FIGS. 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 (left-right direction) of the photosensitive drum 61, determining the left-right position of the developing unit 7 relative to the photosensitive unit 6. The marker 85 of the developing unit 7 is exposed at the bottom of the process cartridge 5 through the contact opening 69 of the photosensitive unit 6.

[0046] As shown in FIGS. 11(a) and 14(b), a box-shaped recess 90L is provided on the frame 610 of the photosensitive unit 6 at one end in the direction of the rotation axis (left-right direction) of the photosensitive drum 61. The recess 90L is positioned so as to overlap the positioning hole 68 when viewed from the direction of the rotation axis (left-right direction) of the photosensitive drum 61. The recess 90L reinforces the surrounding area, which is weakened by the positioning hole 68, thereby increasing its strength. As shown in FIG. 11(b), the depth D2 of the recess 90L is greater than the depth D1 of the positioning hole 68, enhancing the reinforcement effect. This configuration increases the strength of the area around the positioning hole 68 of the photosensitive unit 6 and improves the positioning accuracy of the positioning protrusion 86 of the developing unit 7 and the positioning hole 68 of the photosensitive unit 6 in the left-right direction. As a result, the positioning accuracy between the memory electrode 85A of the memory 85 and the electrode provided in the main body 2 is improved, thereby achieving reliable electrode contact.

[0047] As shown in FIGS. 11(a) and 14(b), a sheet member 93L is provided on the photosensitive drum 61 side of the recess 90L. A leading edge 93LA of the sheet member 93L abuts against the photosensitive drum 61. This configuration allows the leading edge 93LA to scrape off foreign matter, such as unnecessary toner and paper dust, that adheres to the surface of the photosensitive drum 61 during image formation, preventing image defects. In this configuration, the scraped-off foreign matter, such as unnecessary toner and paper dust, falls into the recess 90L and is collected. This prevents contamination of the process cartridge 5 due to scattering of foreign matter and image defects due to foreign matter falling onto the paper S. By using the recess 90L as a reinforcing structure and for collecting foreign matter in this way, it is unnecessary to provide a foreign matter collection structure separate from the recess 90L, thereby achieving a more compact cartridge and a simpler configuration.

[0048] As shown in Figure 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 photosensitive unit 6. A sheet member 93R is provided on the photosensitive drum 61 side of the foreign matter box 90R. A tip end 93RA of the sheet member 93R abuts against the photosensitive drum 61. As with the sheet member 93L described above, To prevent image defects, tip 93RA scrapes off foreign matter such as unnecessary toner and paper dust adhering to the surface of photo drum 61. The scraped-off foreign matter falls into foreign matter box 90R and is collected inside the box.

[0049] 12, pressing member 640 is located in front of frame 610 and is provided at both ends of frame 610 in the left-right direction. Pressing member 640 is biased in the front-to-rear direction by compression spring 640A serving as a biasing member. Therefore, the biasing force of compression spring 640A causes pressing member 640 to press pressed ribs 716A and 716B provided on housing 700 of developing unit 7. By pressing developing unit 7 with pressing member 640, developing roller 71 is biased toward photosensitive drum 61.

[0050] 12 and 7, a recess 664 is provided in the left side wall 611 of the photosensitive unit 6, and the detection unit 80 of the developing unit 7 is located therein. Because the recess 664 reduces the rigidity of the frame 610, a first guide rib 662 is arranged to partially overlap the lower part of the recess 664. This first guide rib 662 acts as a reinforcing member, and can reduce the reduction in rigidity of the frame 610.

[0051] 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 apparatus main body 2, a drive gear (not shown) of the apparatus main body 2 meshes with the photosensitive gear 65, transmitting a driving force to the photosensitive drum 61 and the transfer gear 66, making them rotatable. Furthermore, the transfer gear 66 meshes with a transfer roller gear (third gear) 67 fixed to the left end of the transfer roller 63, making the transfer roller 63 also rotatable.

[0052] <Developing unit 7 lift mechanism> Figure 15 is a partial perspective view of the developing unit 7 and the lift member 642. Figure 16 is a top view of the photosensitive unit 6 with the developing unit 7 attached, with the lift member 642 shown see-through in Figure 16(a) and the lift member 642 shown without see-through in Figure 16(b). Figure 17 is a cross-sectional view of the photosensitive unit 6 and the developing unit 7, with the cross section parallel to the up-down direction and the front-to-back direction. Figure 17(a) shows the developing unit 7 attached to the photosensitive unit 6, and Figure 17(b) shows the developing unit 7 resting on top of the photosensitive unit 6. The developing unit 7 attached to the photosensitive unit 6 is moved to a lifted-up state by a lift mechanism, and then removed from the photosensitive unit 6. This lift mechanism will be described in detail below.

[0053] 15 and 17, at least a portion of the lift member 642 is disposed on the front side of the housing 700 of the developing unit 7, and is rotatably supported on the right side wall 612 while receiving the force of the compression spring 650. Furthermore, at least a portion of the lift member 642 is disposed so as to overlap in the front-to-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 to rotate in the R1 direction.

[0054] When the user presses the operating portion 642A of the lift member 642 against the force of the compression spring 650 and rotates 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 located on the right end side (one end side) of the photosensitive unit 6.

[0055] As shown in FIG. 17(a), in the mounted state in which the developing unit 7 is mounted to the photosensitive unit 6, the pressing member 640 presses the housing 700, thereby pressing the developing roller 71 toward the photosensitive drum 61. The pressing member 640 also locks the developing unit 7 so that it does not detach from the photosensitive unit 6. As shown in FIG. 15, one end of the lift member 642 moves upward the abutment surface (abutment portion) 751A of the protrusion 751 of the housing 700. This allows the developing unit 7 to be moved in the detachment direction LD from the mounted position where it is mounted in the mounting portion 615 (see FIG. 12) and detached from the photosensitive unit 6.

[0056] As shown in FIG. 17(b), when the front portion of the developing unit 7 separates from the photosensitive unit 6, the developing unit 7 is held in a temporary support position where the support surface 700c of the housing 700 is supported by the holding portion 640B of the pressing member 640. Furthermore, when the developing unit 7 is in the temporary support position, the rotation bearing member 746B (746A) of the developing roller 71 is supported by the receiving portion 641. This state is called a lifted-up state. At this time, the lock (which prevents the developing unit 7 from being removed from the photosensitive unit 6) is released. In this lifted-up state, the user can simply grasp the grip portion 701 and lift the developing unit 7, removing the developing unit 7 from the photosensitive unit 6 without moving any other components. In this way, the user can remove the developing unit 7 from the photosensitive unit 6 and install a new developing unit 7 on the photosensitive unit 6.

[0057] Next, the characteristic configuration of the photosensitive unit 6 according to the first embodiment will be described in detail with reference to FIGS.

[0058] Fig. 18 is a cross-sectional view of the photosensitive unit 6 with the cleaning unit 200 attached. Figs. 19 and 20 are diagrams showing the size of each part in the left-right direction of a cleaning unit according to another embodiment that differs in detail from the cleaning unit shown in Fig. 18. Figs. 21(a) and 21(b) are cross-sectional views showing another embodiment of the foreign matter collection recess 242. Fig. 22 is a cross-sectional view of a frame 610 provided with a foreign matter collection portion 620 and a foreign matter collection recess 621.

[0059] 18, the photosensitive unit 6 includes a photosensitive drum 61 and a cleaning unit 200 at the rear in the front-rear direction of a frame 610 that supports the photosensitive drum 61. The cleaning unit 200 also includes a cleaning roller 210 as an example of a first roller, a collection roller 220 as an example of a second roller, a scraping member 230, a case 240, etc. The cleaning unit 200 is detachably attached to the frame 610 of the photosensitive unit 6, and is attached to a unit holding portion 610a that is surrounded by a bottom wall 610b on the bottom side of the frame 610 in the up-down direction and a side wall 610c on the rear side in the front-rear direction. The cleaning unit 200 may be configured to be detachable from the apparatus main body 2.

[0060] The cleaning roller 210 and the collection roller 220 are arranged so that their respective rotation axes are substantially parallel to the rotation axis of the photosensitive drum.

[0061] The cleaning roller 210 is disposed opposite the photosensitive drum 61 between the transfer roller 63 and the charging roller 62 in the rotation direction of the photosensitive drum 61. The cleaning roller 210 contacts the circumferential surface of the photosensitive drum 61 and rotates so that the rotation direction of the photosensitive drum 61 and the rotation direction of the cleaning roller 210 are the same at the contact point between the photosensitive drum 61 and the cleaning roller 210. The cleaning roller 210 may be configured to rotate in response to the rotation of the photosensitive drum 61, or may be configured to rotate by applying a rotational force using a gear or the like.

[0062] The collection roller 220 is disposed opposite the cleaning roller 210. The collection roller 220 contacts the circumferential surface of the cleaning roller 210 and rotates so that the rotation direction of the cleaning roller 210 and the rotation direction of the collection roller 220 are the same at the contact point between the cleaning roller 210 and the collection roller 220. The collection roller 220 may be configured to rotate in conjunction with the cleaning roller 210, or may be configured to rotate by applying a rotational force using a gear or the like.

[0063] The scraping member 230 is formed from a material such as foam, and is disposed so as to be in sliding contact with the circumferential surface of the collection roller 220. To improve sliding properties, a member made of a different material, such as a sheet, may be attached to the surface of the scraping member 230 that comes into contact with the collection roller 220. The case 240 houses the cleaning roller 210 and the collection roller 220. The case 240 also has foreign matter collection sections 241 at least below the collection roller 220 in the vertical direction and behind the collection roller 220 in the front-to-rear direction.

[0064] Next, the removal of toner remaining on the photosensitive drum 61 after the toner image on the photosensitive drum 61 has been transferred onto the paper S, and foreign matter such as paper dust adhering to the surface of the photosensitive drum 61 from the paper S will be described. With the above-described configuration, the developing roller 71 is urged toward the photosensitive drum 61, and in this state, the photosensitive drum 61 and the developing roller 71 are in contact with each other. As a result, the untransferred toner remaining on the photosensitive drum 61 is collected by the developing roller 71 and returned to the developing unit 7.

[0065] On the other hand, most of the foreign matter, such as paper dust, that moves from the paper S to the surface of the photosensitive drum 61 during the transfer process is charged with the same polarity as the transfer voltage applied to the transfer roller 63. Therefore, by applying a voltage of the opposite polarity to the cleaning roller 210, the foreign matter electrostatically moves from the photosensitive drum 61 to the cleaning roller 210. The foreign matter held by the cleaning roller 210 is collected by the collection roller 220. A voltage of the same polarity as the voltage applied to the cleaning roller 210 but greater in absolute value is applied to the collection roller 220. As a result, the foreign matter on the cleaning roller 210 is electrostatically moved to the surface of the collection roller 220. The foreign matter collected on the surface of the collection roller 220 is physically scraped off by the scraping member 230 that comes into contact with the collection roller 220. The foreign matter scraped off by the scraping member 230 is collected in the foreign matter collection unit 241.

[0066] Here, a rotational force is applied to the cleaning roller 210 by a gear or the like, and a speed difference is created between the surface of the cleaning roller 210 and the surface of the photosensitive drum 61. The cleaning roller 210 may have a faster or slower peripheral speed than the photosensitive drum 61. Alternatively, the cleaning roller 210 may rotate so that the rotation direction of the cleaning roller 210 is opposite to the rotation direction of the photosensitive drum 61 at the contact point between the photosensitive drum 61 and the cleaning roller 210. With these configurations, the performance of the cleaning roller 210 in scraping off foreign matter adhering to the photosensitive drum 61 can be improved compared to when the cleaning roller 210 is driven by the photosensitive drum 61.

[0067] Next, the dimensional relationship between the components in the left-right direction will be described with reference to Figure 19. The cleaning roller 210 is provided to be the same size (or width (same below)) as the size of the paper S, or the same size (or length (same below)) as the area where the paper S can come into contact with the photosensitive drum 61 when passing through (maximum paper passing width SL), or larger (or longer (same below)) than these, taking into account dimensional variations of the components, etc. The collection roller 220 is provided to be the same size as the cleaning roller 210, or larger than the cleaning roller 210, taking into account dimensional variations of the components, etc.

[0068] Furthermore, the scraping member 230 is provided to be the same size as the collection roller 220, or larger than the collection roller 220, taking into account dimensional variations of the parts, etc. Alternatively, the scraping member 230 may be provided to be at least the same size as the cleaning roller 210, or larger than the cleaning roller 210, taking into account dimensional variations of the parts, etc.

[0069] Furthermore, the foreign matter collection unit 241 is provided to be the same size as the scraping member 230, or larger than the scraping member 230, taking into account dimensional variations of the components, etc. Alternatively, the foreign matter collection unit 241 may be provided to be at least the same size as the cleaning roller 210, or larger than the cleaning roller 210, taking into account dimensional variations of the components, etc.

[0070] Next, the foreign matter collection unit 241 will be described in detail using Figure 18. As described above, the foreign matter collection unit 241 is provided at least below the collection roller 220 in the up-down direction and on the rear side of the collection roller 220 in the front-to-rear direction. Here, in the case 240, the bottom surface that forms the collection space of the foreign matter collection unit 241 and that intersects with a line L1 drawn downward from the center of rotation of the collection roller 220 in the up-down direction is defined as a first inner bottom surface 240a. In addition, in the case 240, the side surface that forms the collection space of the foreign matter collection unit 241 and that intersects with a line L2 drawn rearward from the center of rotation of the collection roller 220 is defined as a first side surface 240b.

[0071] Foreign matter collection section 241 is a space formed by connecting first inner bottom surface 240a and first side surface 240b, and is formed as a space including collection roller 220. First inner bottom surface 240a is located up and down above bottom wall 610b of opposing frame 610, and first side surface 240b is located forward in the front-to-rear direction above side wall 610c of opposing frame 610.

[0072] Furthermore, a foreign object collection recess 242 is provided in a portion of the first inner bottom surface 240a of the foreign object collection section 241. The foreign object collection recess 242 is provided so as to protrude vertically downward from the first inner bottom surface 240a. In addition, a cutout portion 610d is provided in the bottom wall 610b. The foreign object collection recess 242 protrudes downward in the up-down direction from the first inner bottom surface 240a through the cutout portion 610d, and protrudes to the same height as the bottom wall 610b or, as shown in FIG. 18, protrudes below the bottom wall 610b. This increases the storage capacity for collecting foreign objects.

[0073] In addition, the outer peripheral bottom surface 242a on the vertical lower side of the foreign matter collection recess 242, which is part of the outer wall surface of the foreign matter collection section 241, is configured to be able to come into contact with the paper S when the paper S is transported, thereby making it possible to control the transport direction of the paper S. This makes it possible to use part of the outer wall surface of the foreign matter collection section 241 as a guide for the paper S being transported.

[0074] Thus, the cleaning unit 200 constituting at least a part of the foreign matter collection device of the first embodiment shown in Figure 18 has a frame 610 as a framework, a photosensitive drum 61 as an image carrier that is rotatably supported by the frame 610 and carries a developer image, a cleaning roller 210 as a first collection member that is rotatably supported by the frame 610 and rotates in contact with the surface of the photosensitive drum 61 to collect foreign matter from the surface of the photosensitive drum 61, a collection roller 220 as a second collection member that is rotatably supported by the frame 610 and rotates in contact with the surface of the cleaning roller 210 to further collect the foreign matter collected by the cleaning roller 210 from the cleaning roller 210, and a scraping member 230 that is provided on the frame 610 so as to be able to rub against the rotating collection roller 220 and scrapes off foreign matter from the collection roller 220.

[0075] The frame 610 is a foreign matter collection unit that serves as a storage unit that forms a storage space for storing foreign matter. Foreign matter collection portion 241 has, in an attitude during use, a first inner bottom surface 240a located below scraping member 230 in the direction of gravity, an outer peripheral bottom surface 242a serving as a second inner bottom surface located further below first inner bottom surface 240a, and a connecting surface 240c that intersects first inner bottom surface 240a and outer peripheral bottom surface 242a and connects first inner bottom surface 240a and outer peripheral bottom surface 242a.

[0076] As described above, in the foreign matter collection device of the first embodiment, the foreign matter collection section 241 that stores foreign matter such as paper dust has a foreign matter collection recess 242 that is surrounded by the outer bottom surface 242a and the connection surface 240c further below the first inner bottom surface 240a, thereby improving the foreign matter storage capacity, in other words, increasing the foreign matter storage space.

[0077] Furthermore, when the photosensitive unit 6 is in the posture during use, and the cleaning roller 210, first inner bottom surface 240a, and outer peripheral bottom surface 242a are projected onto the same projection plane as viewed vertically, the cleaning roller 210 is disposed in a position that overlaps with the area of ​​the first inner bottom surface 240a but does not overlap with the area of ​​the outer peripheral bottom surface 242a. This allows the foreign matter collection recess 242, surrounded by the outer peripheral bottom surface 242a and the connecting surface, to be formed in a position that is not below the cleaning roller 210, thereby reducing the space below the cleaning roller 210. As a result, the photosensitive unit 6 can be made more compact.

[0078] Furthermore, foreign matter collection section 241 is provided with partitions 240e that protrude upward in the direction of gravity from first inner bottom surface 240a and that separate the storage space. This allows partitions 240e to function as ribs, improving the strength of case 240 that constitutes foreign matter collection section 241. Furthermore, when collection roller 220 and partitions 240e are projected onto the same plane as viewed vertically in the usage position, partitions 240e are positioned so as to overlap with the area of ​​collection roller 220. This makes it difficult for foreign matter scraped off from collection roller 220 to return to cleaning roller 210, allowing foreign matter to be efficiently collected.

[0079] The outer circumferential bottom surface 242a is disposed on the opposite side of the partition portion 240e from the side on which the photosensitive drum 61 is disposed in the foreign matter recovery portion 241. As a result, the outer circumferential bottom surface 242a is disposed away from the photosensitive drum 61, and therefore, the influence of the outer circumferential bottom surface 242a on the strength of the frame 610 that rotatably supports the photosensitive drum 61 can be reduced.

[0080] Next, modified examples of the photosensitive unit 6 and cleaning unit 200 according to the first embodiment will be described. In the cleaning unit 200 shown in Figures 19 and 20, the recessed portion of the foreign matter collection section 241 is provided on the side surface rather than the bottom surface (see Figures 21(a) and 21(b) described later).

[0081] 19, the area where the paper feed pickup roller 32a provided in the paper feed mechanism 32 is located is an area where a large amount of foreign matter such as paper dust can be generated from the paper S due to the friction between the paper feed pickup roller 32a and the paper S. Therefore, in order to collect as much foreign matter as possible, as shown in FIG. 19, it is preferable that the foreign matter collection recess 242 is longer in the left-right direction than the length D3 of the paper feed pickup roller 32a and overlaps with the area where the paper feed pickup roller 32a is located.

[0082] In this way, the apparatus main body 2 to which the foreign matter collection device is attached is provided with a paper feed pickup roller 32a as a transport roller that transports paper S (recording material) on which an image is recorded. In the longitudinal direction of the paper feed pickup roller 32a, the length of the outer circumferential bottom surface 242a, like the foreign matter collection recess 242, is longer than the length D3 of the transport roller. As mentioned above, paper dust, which is an example of foreign matter, is likely to be generated at the contact point when the paper feed pickup roller 32a transports the paper S. Therefore, the length of the storage portion of the foreign matter collection section 241 is set to be longer than the longitudinal length D3 of the paper feed pickup roller 32a. By increasing the length of the outer circumferential bottom surface 242a that constitutes part of the space, paper dust resulting from the paper sheet S transported by the paper feed pickup roller 32a can be efficiently collected.

[0083] Furthermore, in the left-right direction, the paper width end SE of the paper S is also an area where a large amount of foreign matter such as paper dust can be generated. Therefore, in order to collect as much foreign matter as possible, the foreign matter collection recess 242 is preferably provided to be larger in the left-right direction than the maximum paper passing width (maximum width of the paper S) SL and overlap the area of ​​the paper width end SE of the paper S. Alternatively, the foreign matter collection recess 242 is preferably larger in the left-right direction than the minimum width of the paper S transported by the paper feed pickup roller 32a. Alternatively, it is preferable that both ends of the foreign matter collection recess 242 are located outside both ends of the paper feed pickup roller 32a in the left-right direction. This allows for efficient collection of paper dust resulting from the paper S transported by the paper feed pickup roller 32a. However, if the foreign matter collection recess 242 is made larger than the maximum paper passing width SL in the left-right direction, for example, the cutout portion 610d (or cutout portion 610e) in the bottom wall 610b shown in Figure 18 (or the side wall 610c shown in Figure 19) will become larger, and there is a concern that the rigidity of the frame 610 will decrease.

[0084] Therefore, in order to reduce the decrease in rigidity of frame 610, foreign matter collection recess 242 may be made smaller than maximum sheet passing width SL in the left-right direction, and notch 610d (notch 610e) in bottom wall 610b (side wall 610c) may be made smaller. Alternatively, in order to reduce the decrease in rigidity of frame 610 and increase the storage capacity for collecting foreign matter, multiple foreign matter collection recesses 242 may be provided in the left-right direction, and notch 610e in side wall 610c may be made smaller, as shown in FIG.

[0085] When providing multiple foreign matter collection recesses 242 in the left-right direction, it is preferable to provide the foreign matter collection recesses 242 in locations where a large amount of foreign matter such as paper dust is generated. In other words, in order to collect as much foreign matter as possible, it is preferable to provide the foreign matter collection recesses 242 in the left-right direction at positions overlapping the paper feed pickup roller 32a and the paper width end portion SE of the paper S.

[0086] As shown in Figures 21(a) and 21(b), the foreign matter collection recess 242 may be provided so as to protrude rearward in the front-to-rear direction from the first side surface 240b. In this case, a notch 610e is provided in the side wall 610c. The foreign matter collection recess 242 protrudes rearward in the front-to-rear direction from the first side surface 240b through the notch 610e, and protrudes to the same position as the side wall 610c or, as shown in Figures 21(a) and 21(b), protrudes further rearward than the side wall 610c. The shape and arrangement in the left-to-right direction are the same as those described above, and therefore will not be described here.

[0087] Thus, the foreign matter collection section 241 has, in the posture during use, a first side surface 240b located rearward of the frame 610 in the fore-and-aft direction, a second side surface 240f located farther from the scraping member 230 than the first side surface 240b, and a connecting surface 240g that intersects with the first side surface 240b and the second side surface 240f and connects the first side surface 240b and the second side surface 240f.

[0088] As a result, the foreign matter collection section 241, which stores foreign matter such as paper dust, has a foreign matter collection recess 242 surrounded by the second side surface 240f, which is located further away from the scraping member 230 than the first side surface 240b, and the connecting surface 240g, thereby improving the foreign matter storage capacity, in other words, increasing the foreign matter storage space.

[0089] The foreign matter collecting recess 242 may be provided on both the first inner bottom surface 240a and the first side surface 240b (FIG. 21(b)), or may be provided on both the first inner bottom surface 240a and the first side surface 240b. b may be provided with a plurality of foreign matter collecting recesses 242. The plurality of foreign matter collecting recesses 242 may be combined to form a part of the foreign matter collecting section 241.

[0090] As described above, by providing the foreign matter collection recess 242 in a part of the foreign matter collection section 241, it is possible to increase the storage capacity for collecting foreign matter such as paper dust.

[0091] In the present embodiment, the foreign matter collection recess 242 is disposed by providing the cutout 610d in the bottom wall 610b or the cutout 610e in the side wall 610c, but this is not limiting. For example, the bottom wall 610b of the frame 610 may be disposed vertically lower within a range that does not affect the paper transport path, and the foreign matter collection recess 242 may be disposed vertically higher than the bottom wall 610b of the frame 610. In this case, the bottom wall 610b of the frame 610 may be configured to control the transport direction of the paper S by coming into contact with the paper S as it is transported.

[0092] Furthermore, the side wall 610c of the frame 610 may be disposed rearward in the front-to-rear direction within a range where there is no interference with the device main body, and the foreign object collection recess 242 may be provided forward in the front-to-rear direction from the side wall 610c of the frame 610. With this configuration, it is not necessary to provide the notch 610d in the bottom wall 610b or the notch 610e in the side wall 610c as described above, and therefore it is possible to reduce a decrease in the rigidity of the frame 610.

[0093] Furthermore, in the present embodiment, a configuration has been described in which the cleaning unit 200 is detachably attached to the frame 610 of the photosensitive unit 6, but this is not limitative. For example, as shown in Fig. 22, the cleaning roller 210, the collection roller 220, and the scraping member 230 are attached to the frame 610 of the photosensitive unit 6, and the bottom wall 610b and the side wall 610c form a foreign matter collection section 620. A foreign matter collection recess 621 may be provided in the bottom wall 610b, the side wall 610c, or both the bottom wall 610b and the side wall 610c.

[0094] Furthermore, in the present embodiment, the cleaning unit 200, which includes the cleaning roller 210, the collection roller 220, the scraping member 230, and the foreign matter collection section 241 in the case 240, is configured to be detachable from the photosensitive unit 6, but this is not limitative. For example, the case 240, which includes at least the foreign matter collection section 241, may be configured to be detachable from the photosensitive unit 6. That is, for example, the case 240, which includes the foreign matter collection section 241 and the scraping member 230, or the case 240, which includes the foreign matter collection section 241, the collection roller 220, and the scraping member 230, may be configured to be detachable from the photosensitive unit 6.

[0095] [Second embodiment] Next, a second embodiment of the present invention will be described with reference to Figure 23. In this embodiment, parts that differ from the previously described embodiment will be described in detail. Unless otherwise specified, the configuration is the same as in the previously described embodiment, so the same numbers are used for such parts and detailed description will be omitted. The same applies to the other embodiments described below. Figures 23(a) and 23(b) are cross-sectional views of the arrangement of a foreign object transport member 250 of the second embodiment.

[0096] As shown in FIG. 23(a), a foreign object transport member 250 is provided below the foreign object collection section 241 in the vertical direction. The foreign object transport member 250 is formed by a shaft portion 250a and a transport portion 250b, and is rotated by a driving means (not shown) with a rotation axis extending in the left-right direction. Alternatively, the foreign object transport member 250 may be configured to perform a swinging motion with a rotation axis extending in the left-right direction. Alternatively, the foreign object transport member 250 may be configured to perform a linear reciprocating motion at least in the front-rear direction. In other words, the foreign object transport member 250 is configured such that it can move inside the foreign object collection section 241. Various configurations can be adopted as long as they are capable of acting on foreign matter such as paper dust contained in the foreign matter collection section 241 by moving.

[0097] When foreign matter such as paper dust scraped by scraping member 230 is collected in foreign matter collection section 241, it accumulates on the upper and lower upper sides of foreign matter collection section 241. Therefore, by operating foreign matter transport member 250, the foreign matter can be moved forward in the front-to-back direction by transport section 250b. This evens out the accumulated foreign matter, forming an evenly stacked state, allowing the foreign matter to be efficiently collected in foreign matter collection section 241.

[0098] 23(b), a configuration in which a foreign object collection recess 242 is provided in a foreign object collection section 241 may also be provided with a foreign object transport member 250. Transport section 250b may be formed integrally with shaft section 250a or may be formed separately. Transport section 250b may be formed from a sheet-like material, may be formed in a slat-like flat plate shape, or may be formed in a spiral shape.

[0099] Furthermore, in order to efficiently collect foreign matter such as paper dust in the foreign matter collection section 241, it is preferable to provide the transport section 250b of the foreign matter transport member 250 across the entire inside of the foreign matter collection section 241 in the left-right direction. Alternatively, it is preferable to provide the foreign matter collection recess 242 in the foreign matter collection section 241 and provide the transport section 250b at a position facing at least the foreign matter collection recess 242.

[0100] As described above, the foreign object collection device shown in FIG. 23 includes a foreign object collection section 241 that forms a storage space for storing foreign objects, and a foreign object transport member 250 that transports foreign objects within the storage space. By providing the foreign object transport member 250 below the foreign object collection section 241, foreign objects such as paper dust can be efficiently stored in the foreign object collection section 241 and moved within the storage space. In other words, the storage space can be efficiently utilized to increase the amount of foreign objects that can be stored. Note that the foreign object collection recess 242 shown in FIG. 18 may be provided below the foreign object collection section 241 shown in FIG. 23.

[0101] [Third embodiment] Next, a third embodiment of the present invention will be described with reference to Fig. 24. Fig. 24 is a cross-sectional view showing a state in which a rotatable collection conveying sheet 260 is in contact with a collection roller 220.

[0102] 24, a collection conveying sheet 260 (third collection member) is provided in the foreign object collection section 241. The collection conveying sheet 260 is formed by a shaft 260a and a collection conveying section 260b, which is made of a flexible sheet material and rotates about a rotation axis extending in the left-right direction by a driving means (not shown). Furthermore, when the collection conveying sheet 260 rotates, the leading edge of the collection conveying section 260b abuts against the outer peripheral surface of the collection roller 220 as it approaches the collection roller 220, and moves away from it as it moves away.

[0103] The reasons for allowing the recovery and conveyance sheet 260 to come into contact with the recovery roller 220 (second recovery member) midway through its rotation, as in this embodiment, are, first, to remove foreign matter such as paper dust remaining on the recovery roller 220 and convey it to the foreign matter recovery section 241, second, to extend the life of the scraping member 230, and third, to prevent the charge polarity of the foreign matter on the recovery roller 220 from being reversed. The reasons are explained in detail below.

[0104] Since the collection roller 220 and the scraping member 230 are in constant contact, in a process cartridge with a long life, the scraping member may wear out and the scraping ability may decrease. The scraping member 230 wears out because large foreign objects get caught between the collection roller 220 and the scraping member 230 and rotate in that state for a long time. When the scraping member 230 wears out, the foreign objects pass through in a streak along the direction of rotation of the collection roller 220. Some of the foreign objects that have passed through in a streak-like manner are rubbed against each other as they rotate around the collection roller 220. The foreign matter with the reversed polarity is electrostatically transferred from the collection roller 220 to the cleaning roller 210, and then transferred from the cleaning roller 210 to the photosensitive member 61, which may cause image defects.

[0105] In this embodiment, the rotatable collection conveying sheet 260 is brought into contact with the collection roller 220 during rotation, and when the collection conveying sheet 260 comes into contact with the collection roller 220, the difference in peripheral speed (relative movement) causes the collection conveying sheet 260 to brush off large foreign matter on the collection roller 220 and convey it to the foreign matter collection section 241. In addition, the contact position of the collection conveying sheet 260 with the collection roller 220 is upstream of that of the scraping member 230 in the rotation direction of the collection roller 220, so that the collection roller 220 is less likely to enter the scraping member 230 with large foreign matter adhering thereto, thereby enabling the scraping member 230 to have a longer life.

[0106] For foreign matter that is not brushed off by the collection conveying sheet 260 and remains on the collection roller 220, the charge polarity is maintained so that it does not change due to the rubbing between the collection conveying portion 260b of the collection conveying sheet 260 and the foreign matter. Therefore, it is preferable to use a material that can maintain the charge polarity of the foreign matter for the collection conveying portion 260b of the collection conveying sheet 260. It is conceivable to select a material such as Teflon (registered trademark) if it is desired to maintain the foreign matter positively charged, or nylon if it is desired to maintain the foreign matter negatively charged, but there is no limitation to these as long as the material can achieve the maintenance of the charge polarity of the foreign matter.

[0107] While this embodiment illustrates an example of a recovery conveying sheet having a shaft portion 260a and a recovery conveying portion 260b, other configurations may be used as long as they achieve the above-described functions. For example, a roller with a spirally wound sponge or brush can also be effective. Furthermore, the recovery conveying sheet 260 and the recovery roller 220 do not need to be in uniform contact with each other; their rotation axes may or may not be parallel. Furthermore, the rotation direction of the recovery conveying sheet 260 relative to the rotation direction of the recovery roller 220 may be either forward or reverse. In other words, any configuration is acceptable as long as the third recovery member can be brought into contact with the second recovery member and a difference in peripheral speed (relative movement) occurs between the contact surfaces at the contact portion. For example, if the contact surfaces of the second and third recovery members at the contact portion move in the same direction, the moving speed of the contact surface of the third recovery member can be controlled to be slower than the moving speed of the contact surface of the second recovery member, thereby scraping off adhering materials from the second recovery member. Furthermore, by controlling the contact surfaces of the second and third collection members to move in different directions at the contact portion, it is possible to scrape off the deposits from the second collection member. Note that the third collection member may be in contact with the second collection member intermittently or may be in contact with the second collection member at all times.

[0108] [Fourth embodiment] Next, a fourth embodiment of the present invention will be described with reference to Figures 25 and 26. Figure 25 is a cross-sectional view showing the rotation direction of cleaning roller 210 and collection roller 220. Figure 26 is a cross-sectional view showing another embodiment of scraping member 231.

[0109] As described above, the collection roller 220 rotates in contact with the surface of the cleaning roller 210, so that foreign matter such as paper dust held by the cleaning roller 210 is held by the collection roller 220. Here, in order to improve the performance of scraping off foreign matter adhering to the cleaning roller 210, it is advisable to increase the area of ​​contact between the collection roller 220 and the surface of the cleaning roller 210.

[0110] In addition, it is preferable to provide a speed difference between the surface of the collection roller 220 and the surface of the cleaning roller 210, so that the surfaces of the cleaning roller 210 and the collection roller 220 are rubbed against each other. This is done by applying a rotational force to the cleaning roller 210 and the collection roller 220 using gears or the like. 25, the collection roller 220 rotates in the opposite direction to the cleaning roller 210 at the contact point between the cleaning roller 210 and the collection roller 220.

[0111] That is, the cleaning roller 210 and the collection roller 220 are rotationally driven so that the surfaces of the cleaning roller 210 and the collection roller 220 move in opposite directions at the contact portion where the cleaning roller 210 and the collection roller 220 come into contact with each other.

[0112] This further improves the ability to scrape off foreign matter adhering to the cleaning roller 210. However, there is a concern that an increase in rotational load torque may occur due to the collection roller 220 rotating in the opposite direction to the cleaning roller 210. Therefore, by using a brush roller, low-resilience sponge, low-resistance sponge, a roller with a spirally wound sponge, or the like for the collection roller 220, the increase in rotational load can be suppressed.

[0113] Next, we will explain the configuration in which foreign matter such as paper powder held on the surface of the collection roller 220 is collected in the foreign matter collection section 241 when the collection roller 220 rotates so as to move in the opposite direction relative to the cleaning roller 210 at the contact point where the cleaning roller 210 and the collection roller 220 come into contact.

[0114] 26(a), scraping member 231 is disposed in the circumferential direction of collection roller 220 so as to be downstream in the rotation direction of straight line L connecting the centers of rotation of cleaning roller 210 and collection roller 220. This is to prevent foreign matter collected in foreign matter collection section 241 from adhering again to cleaning roller 210. Furthermore, scraping member 231 is formed from a foam material, and is fixed to scraping member 231 holder 240d provided in case 240.

[0115] In other words, when viewed from the direction of the rotation axis of the collection roller 220, the scraping member 231 is disposed on the opposite side to the side where the photosensitive drum 61 is located with respect to the imaginary line L connecting the rotation center of the cleaning roller 210 and the rotation center of the collection roller 220. This makes it easier for the foreign matter scraped off by the scraping member 231 to move in the direction opposite to the side where the photosensitive drum 61 is located.

[0116] The scraping member 231 may be a rubber blade or a metal blade. With this configuration, the foreign matter scraped off from the collection roller 220 can be collected in the foreign matter collection section 241 without adhering to the cleaning roller 210 again. Also, as shown in FIG. 26(b), a foreign matter collection recess 242 may be provided in the foreign matter collection section 241, and the rotation direction of the collection roller 220 and the arrangement of the scraping member 231 may be arranged as described above.

[0117] As described above, by rotating the collection roller 220 in the opposite direction to the cleaning roller 210 and by devising an arrangement of the scraping member 231, the collection roller 220 can efficiently scrape off foreign matter such as paper dust from the cleaning roller 210.

[0118] In carrying out the present invention, the configurations and arrangements described in the above-described embodiments can be appropriately selected and combined within the scope of no contradiction.

[0119] For example, (1) the foreign matter collecting section 241 shown in FIG. 18 may be provided with the foreign matter transport member 250 shown in FIG. 24(a) or 24(b). Alternatively, (2) the foreign matter collecting section 241 shown in FIG. 21(a) or FIG. 21(b) may be provided with a foreign matter transporting member 250 shown in FIG. 24(a) or FIG. 24(b). 24(a) or 24(b) in the foreign matter collecting recess 621 shown in FIG. 22. A foreign object transport member 250 may be provided. Alternatively, (4) the foreign matter collecting section 241 shown in FIG. 25 may be provided with the foreign matter transporting member 250 shown in FIG. 24(a) or 24(b). Alternatively, (5) the foreign matter collecting section 241 shown in FIG. 26(a) or FIG. 26(b) may be provided with the foreign matter transporting member 250 shown in FIG. 24(a) or FIG. 24(b). Alternatively, (6) a foreign matter collecting recess 242 shown in FIG. 21(a) or 21(b) may be provided behind the first side surface 240b of the foreign matter collecting portion 241 shown in FIG. 25 or 26(a). Alternatively, a plurality of the above-described configurations (1) to (6) may be combined. [Explanation of symbols]

[0120] 1...image forming apparatus, 2...apparatus main body, 5...process cartridge, 6...photosensitive unit, 7...developing unit, 32a...paper feed pickup roller, 61...photosensitive drum, 71...developing roller, 200...cleaning unit, 210...cleaning roller, 220...recovery roller, 230, 231...scraping member, 240...case, 240a...first inner bottom surface, 240b...first side surface, 240c...connecting surface, 240d...holding portion, 240e...partition portion, 240f...second side surface, 240g...connecting surface, 241...foreign matter recovery portion, 242...foreign matter recovery recess, 242a...outer peripheral bottom surface, 250...foreign matter transport member, 250a...shaft portion, 250b...transport portion, 260...recovery transport sheet, 260a...shaft portion, 260b...recovery transport portion, 610...frame

Claims

1. A frame body, an image carrier rotatably supported by the frame and carrying a developer image; a first recovery member that is rotatably supported by the frame and that recovers foreign matter from the surface of the image carrier by rotating in contact with the surface of the image carrier; a second recovery member that is rotatably supported by the frame and rotates while in contact with a surface of the first recovery member, thereby recovering the foreign matter recovered by the first recovery member from the first recovery member; a scraping member provided on the frame so as to be able to slide against the rotating second collection member, for scraping the foreign matter from the second collection member; a third retrieval member capable of contacting the second retrieval member, the third retrieval member having a shaft portion and a seat portion attached to the shaft portion; the third recovery member is controlled to contact an outer circumferential surface of the second recovery member during a rotational movement of the second recovery member; The foreign object recovery device is characterized in that the outer peripheral surface of the seat portion is capable of abutting against the second recovery member.

2. The foreign matter recovery device according to claim 1, characterized in that the first recovery member and the second recovery member are rotationally driven so that the surfaces of the first recovery member and the second recovery member move in opposite directions at the contact portion where the first recovery member and the second recovery member come into contact.

3. The foreign matter recovery device described in claim 2, characterized in that, when viewed from the direction of the rotation axis of the second recovery member, the scraping member is arranged on the opposite side of the virtual line connecting the rotation center of the first recovery member and the rotation center of the second recovery member from the side on which the image carrier is located.

4. The foreign matter recovery device according to claim 1 ; a charging member for charging the image bearing member.

5. a developer carrier that carries a developer; 5. A process cartridge according to claim 4, wherein the developer remaining on the image carrier after transfer from the image carrier is collected by the developer carrier.

6. 6. A process cartridge according to claim 4, further comprising a transfer member for transferring a developer image from said image bearing member.

7. 5. The process cartridge according to claim 4, which is detachably mountable to the main body of the image forming apparatus.

8. The foreign matter recovery device according to claim 1 ; and a fixing member.

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