Developing cartridge used in image forming apparatus

Abstract

To provide a new form of a developing cartridge.SOLUTION: A developing cartridge comprises: a developer container that has a first frame body including a first projection and a second frame body including a second projection and is provided with an opening communicating with a storage space; a developing roller that faces the opening; and a stirring member that includes a rotation shaft rotatable about a rotation axis and a sheet fixed to the rotation shaft. On a cross-section perpendicular to the rotation axis, the first projection and the second projection are on the inside of a virtual circle that is a rotation locus of a leading end of the sheet in a non-bent state when the rotation shaft rotates. A first leading end surface of the first projection and a second leading end surface of the second projection face each other with a gap therebetween. The gap is set such that the first leading end surface and the second leading end surface are brought into contact with each other when the developer container is pressed by the external force in a direction in which the first frame body and the second frame body approach each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a developing cartridge used in an electrophotographic image forming apparatus. [Background technology]

[0002] 2. Description of the Related Art In an image forming apparatus using an electrophotographic image forming process, a configuration is known in which a developing cartridge is detachably mounted on a tray that can be pulled out from the main body of the apparatus (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-124533 Summary of the Invention [Problem to be solved by the invention]

[0004] SUMMARY OF THE INVENTION An object of the present invention is to provide a new type of developing cartridge. [Means for solving the problem]

[0005] A first aspect of the present invention is a developer cartridge, comprising: a developer container having a first frame including a first inner wall and a first protruding portion protruding from the first inner wall; a second frame including a second inner wall that defines a toner storage space together with the first inner wall and a second protruding portion protruding from the second inner wall and that is aligned with the first frame in a first direction, the developer container having an opening that communicates with the storage space; a developer roller provided opposite the opening; and an agitating member provided in the storage space, the agitating member including a rotation shaft that is rotatable about a rotation axis that extends in a direction intersecting with the first direction; and a sheet having one end and the other end in a direction perpendicular to the rotation axis that are a fixed end fixed to the rotation shaft and a free end, respectively. a stirring member, wherein at least a portion of the first protrusion and at least a portion of the second protrusion are located inside an imaginary circle that is a rotation trajectory of the tip of the free end of the sheet when the sheet is not bent when the rotation axis rotates, in a cross section perpendicular to the rotation axis, a first tip surface of the first protrusion in the first direction and a second tip surface of the second protrusion in the first direction face each other with a gap in between, in the cross section, and the gap is set so that when the developing container is pressed by an external force in a direction that causes the first frame body and the second frame body to approach each other in the first direction, the developing container elastically deforms and the first tip surface and the second tip surface come into contact with each other. [Effects of the Invention]

[0006] According to the present invention, a new form of developing cartridge can be provided. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a cross-sectional view illustrating the configuration of a developing unit according to the first embodiment. [Figure 2] 1 is a schematic cross-sectional view of an image forming apparatus according to a first embodiment. [Figure 3] FIG. 2 is a cross-sectional view of the cartridge according to the first embodiment. [Figure 4] FIG. 1 is a cross-sectional view of an image forming apparatus according to a first embodiment. [Figure 5] FIG. 1 is a cross-sectional view of an image forming apparatus according to a first embodiment. [Figure 6] FIG. 1 is a cross-sectional view of an image forming apparatus according to a first embodiment. [Figure 7] FIG. 2 is an exploded perspective view of the drum unit according to the first embodiment. [Figure 8] FIG. 1 is an exploded perspective view of a development unit according to a first embodiment; [Figure 9] FIG. 2 is an assembled perspective view of the cartridge according to the first embodiment. [Figure 10] FIG. 2 is a perspective view of a cartridge according to the first embodiment. [Figure 11] FIG. 2 is a diagram illustrating a first frame according to the first embodiment. [Figure 12] FIG. 4 is a diagram illustrating a second frame according to the first embodiment. [Figure 13] 5A to 5C are diagrams illustrating deformation of the developing frame according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] The best mode for carrying out the present invention will be described in detail below with reference to the drawings and examples. However, the functions, materials, shapes, dimensions, and relative positions of the components described in the examples may be changed as appropriate depending on the configuration of the device to which the invention is applied and various conditions, and unless otherwise specified, the scope of the present invention is not intended to be limited to these. [Example]

[0009] A first embodiment (Example 1) of the present invention will be described below with reference to the drawings. In the first embodiment, an image forming apparatus to which four cartridges can be detachably attached is exemplified as the image forming apparatus. However, the number of cartridges attached to the image forming apparatus is not limited to this. It can be set appropriately as needed. Furthermore, in the embodiment described below, a laser beam printer is exemplified as one aspect of the image forming apparatus.

[0010] <General configuration of image forming apparatus> The overall configuration of an electrophotographic image forming apparatus 1 according to this embodiment will be described with reference to Fig. 2. Fig. 2 is a schematic cross-sectional view of the image forming apparatus 1. Fig. 3 is a schematic cross-sectional view of a cartridge 100.

[0011] The image forming apparatus 1 is a four-color full-color laser beam printer that uses an electrophotographic process, and forms a color image on a recording medium 3. The image forming apparatus 1 is of a cartridge type, and a cartridge 100 is removably attached to the apparatus main body 2 to form a color image on the recording medium 3.

[0012] Here, with respect to the image forming apparatus 1, the side where the front door 10 is provided is referred to as the front (front face), and the side opposite the front is referred to as the back (rear face). When viewing the image forming apparatus 1 from the front, the right side is referred to as the drive side, the left side is referred to as the non-drive side, the upper side is referred to as the top face, and the lower side is referred to as the bottom face. Figure 2 is a cross-sectional view of the image forming apparatus 1 viewed from the non-drive side, with the front side of the page being the non-drive side of the image forming apparatus 1, the right side of the page being the front of the image forming apparatus 1, and the back side of the page being the drive side of the image forming apparatus 1.

[0013] The drive side of the cartridge 100 is the side on which the drum coupling member (photosensitive member coupling member) described later is arranged when viewed in the direction of the rotation axis RA3 of the photosensitive drum 101, and is the side on which the development coupling member described later is arranged when viewed in the direction of the rotation axis RA2 of the development roller 103 (developing member).

[0014] A first cartridge 100Y, a second cartridge 100M, a third cartridge 100C, and a fourth cartridge 100K (hereinafter referred to as the first to fourth cartridges 100) are arranged in a substantially horizontal direction in the apparatus main body 2. The first to fourth cartridges 100 each have a similar electrophotographic process mechanism, but differ in toner color and filling amount. Therefore, in the following, unless a distinction is particularly required, the suffixes Y to K will be omitted and the cartridges will be described collectively.

[0015] A rotational driving force is transmitted to the first to fourth cartridges 100 (developing cartridges) from a drive output unit (details of which will be described later) of the apparatus main body 2, and bias voltages (charging bias, developing bias, electrostatic residual detection bias, etc.) are supplied from contacts of the apparatus main body 2 (not shown). As shown in FIG. 3, the cartridge 100 of this embodiment has a drum unit 120 including a photosensitive drum 101 and a charging roller 102 (charging means) as a process means acting on the photosensitive drum 101. Here, the drum unit 120 may also include a cleaning means, such as a blade, for cleaning the photosensitive drum 101 as a process means. The cartridge 100 also has a developing unit 150 including a developing means for developing an electrostatic latent image on the photosensitive drum 101. The drum unit 120 and the developing unit 150 are coupled to each other. A more specific configuration of the cartridge 100 will be described later.

[0016] The first cartridge 100Y accommodates yellow (Y) toner in the developing frame and forms a yellow toner image on the surface of the photosensitive drum 101. The second cartridge 100M accommodates magenta (M) toner in the developing frame and forms a magenta toner image on the surface of the photosensitive drum 101. The third cartridge 100C accommodates cyan (C) toner in the developing frame and forms a cyan toner image on the surface of the photosensitive drum 101. The fourth cartridge 100K accommodates black (K) toner in the developing frame and forms a black toner image on the surface of the photosensitive drum 101. A laser scanner unit 11 is provided above the first to fourth cartridges 100 as an exposure means. This laser scanner unit 11 outputs a laser beam 12 corresponding to image information. The laser beam 12 passes through an exposure window 128 of the cartridge 100 and scans and exposes the surface of the photosensitive drum 101.

[0017] An intermediate transfer unit 5 serving as a transfer member is provided below the first to fourth cartridges 100. This intermediate transfer unit 5 includes a drive roller 5e, a turn roller 5c, and a tension roller 5b, around which a flexible transfer belt 5a is wound. The photosensitive drums 101 of the first to fourth cartridges 100 contact the transfer belt 5a to form a contact portion. This contact portion is the primary transfer portion. A primary transfer roller 5d is provided inside the transfer belt 5a so as to face the photosensitive drum 101. A secondary transfer roller 6 is in contact with the drive roller 5e via the transfer belt 5a. The contact portion between the transfer belt 5a and the secondary transfer roller 6 is the secondary transfer portion. A feeding unit 4 is provided below the intermediate transfer unit 5. This feeding unit 4 includes a paper feed tray 4a that holds a stack of recording media 3 and a paper feed roller 4b. A fixing device 7 and a paper discharge device 8 are provided in the upper right corner of the device main body 2 in FIG. 2, and a paper discharge tray 9 is provided on the top surface of the device main body 2. The toner image is fixed onto the recording medium 3 by a fixing means provided in a fixing device 7 , and the recording medium 3 is discharged onto a paper discharge tray 9 .

[0018] <Image formation operation> The operation for forming a full-color image is as follows: The photosensitive drums 101 of the first to fourth cartridges 100 are rotated at a predetermined speed (direction of arrow A in FIG. 3). The transfer belt 5a is also rotated in the forward direction (direction of arrow B in FIG. 2) relative to the rotation of the photosensitive drums 101 at a speed corresponding to the speed of the photosensitive drums 101. The laser scanner unit 11 is also driven. In synchronization with the drive of the laser scanner unit 11, the charging roller 102 in each cartridge 100 uniformly charges the surface of the photosensitive drum 101 to a predetermined polarity and potential. The laser scanner unit 11 scans and exposes the surface of each photosensitive drum 101 with laser light 12 in accordance with an image signal for each color. As a result, an electrostatic latent image corresponding to the image signal for the corresponding color is formed on the surface of each photosensitive drum 101. The formed electrostatic latent image is developed by the developing roller 103, which is rotated at a predetermined speed in the forward direction (direction of arrow C in FIG. 3) relative to the rotation of the photosensitive drum 101. By performing this image formation process, a yellow toner image corresponding to the yellow component of the full-color image is formed on the photosensitive drum 101 of the first cartridge 100Y. This toner image is then primarily transferred onto the transfer belt 5a. Similarly, a magenta toner image corresponding to the magenta component of the full-color image is formed on the photosensitive drum 101 of the second cartridge 100M. This toner image is then primarily transferred and superimposed on the yellow toner image already transferred onto the transfer belt 5a. Similarly, a cyan toner image corresponding to the cyan component of the full-color image is formed on the photosensitive drum 101 of the third cartridge 100C. This toner image is then primarily transferred and superimposed on the yellow and magenta toner images already transferred onto the transfer belt 5a. Similarly, a black toner image corresponding to the black component of the full-color image is formed on the photosensitive drum 101 of the fourth cartridge 100K. This toner image is then primarily transferred and superimposed on the yellow, magenta, and cyan toner images already transferred onto the transfer belt 5a. In this way, an unfixed full-color toner image of four colors, yellow, magenta, cyan, and black, is formed on the transfer belt 5a.

[0019] Meanwhile, recording media 3 are separated and fed one by one at a predetermined control timing. The recording media 3 are introduced into a secondary transfer section, which is the contact point between a secondary transfer roller 6 and a transfer belt 5a, at a predetermined control timing. As a result, as the recording media 3 is transported to the secondary transfer section, the four-color superimposed toner image on the transfer belt 5a is sequentially transferred all at once onto the surface of the recording media 3. The configuration of the device main body will be described in more detail below.

[0020] <Outline of cartridge installation / removal configuration> The tray 20 supporting the first to fourth cartridges 100 will be described in further detail with reference to Figures 4 to 6. Figure 4 is a cross-sectional view of the image forming apparatus 1 with the front door 10 open and the tray 20 positioned inside the apparatus main body 2. Figure 5 is a cross-sectional view of the image forming apparatus 1 with the front door 10 open and the tray 20 positioned outside the apparatus main body 2, with the cartridges 100 supported on the tray 20. Figure 6 is a cross-sectional view of the image forming apparatus 1 with the front door 10 open and the tray 20 positioned outside the apparatus main body 2, with the cartridges 100 removed from the tray 20.

[0021] 4 and 5, the tray 20 is movable in the direction of arrow X1 (pushing direction) and the direction of arrow X2 (pulling out direction), which are substantially horizontal to the device main body 2. That is, the tray 20 is provided so as to be able to be pulled out and pushed into the device main body 2, and is configured so as to be movable in a substantially horizontal direction when the device main body 2 is installed on a horizontal surface. Here, the state in which the tray 20 is located inside the device main body 2 with the front door 10 open (the state in FIG. 4) is referred to as the inside position. Also, the state in which the tray 20 is located outside the device main body 2 (the state in FIG. 5) is referred to as the outside position. In these inside and outside positions, the photosensitive drum 101 and the transfer belt 5a are spaced apart.

[0022] The tray 20 has a mounting portion 20a in the outer position, into which the first cartridge 100Y can be removably attached, as shown in FIG. 6 . The tray 20 also has mounting portions 20a into which the second to fourth cartridges 100 can be removably attached. The cartridge 100, while placed in the mounting portion 20a, moves toward the inside of the apparatus main body 2 by moving the tray 20. In this embodiment, when the front door 10 is closed, the intermediate transfer unit 5 is raised in the direction of arrow Z1 by a link mechanism (not shown) and moves to a position for image formation (a position where the photosensitive drum 101 and the transfer belt 5a contact each other). When the front door 10 is opened, the intermediate transfer unit 5 is lowered in the direction of arrow Z2, and the photosensitive drum 101 and the transfer belt 5a are separated from each other. In this manner, in the image forming apparatus 1 of this embodiment, the tray 20 allows multiple cartridges 100 to be moved together to a position inside the apparatus main body 2 where image formation is possible, and also allows the cartridges 100 to be pulled out together to the outside of the apparatus main body 2.

[0023] <Overall cartridge configuration> The configuration of the cartridge will be described with reference to Figures 7 to 10. Figure 7 is an exploded perspective view of the drum unit 120. Figure 8 is an exploded perspective view of the development unit 150. Figure 9 is an assembled perspective view of the cartridge 100 as seen from the drive side, which is one end side in the axial direction of the photosensitive drum 101. Figure 10 is a perspective view of the cartridge 100 as seen from the drive side. In the drawings, the X direction, Y direction, and Z direction are orthogonal (intersecting) to one another.

[0024] The cartridge 100 includes a photosensitive drum 101 and a process means acting on the photosensitive drum 101. The process means includes a charging roller 102 as a charging means for charging the photosensitive drum 101, and a developing roller 103 as a developing means for developing the latent image formed on the photosensitive drum 101. The cartridge 100 also includes a drum unit 120 and a developing unit 150.

[0025] In the following description, as shown in Figures 8 and 9, the longitudinal direction of the drum unit 120 and the developing unit 150 is a direction (Y direction) that is approximately parallel to the direction of the rotation axis RA3 of the photosensitive drum 101 and the direction of the rotation axis RA2 of the developing roller 103.

[0026] <Drum unit configuration> 7 and 9, the drum unit 120 is composed of a photosensitive drum 101, a charging roller 102, and a drum frame 121. The charging roller 102 is rotatably supported by a driving-side charging roller bearing 126a and a non-driving-side charging roller bearing 127a, and is urged toward the photosensitive drum 101 (in the direction of arrow F in FIG. 3) by pressure springs 126b and 127b. The photosensitive drum 101 is rotatably supported by a first drum cover member 122 and a second drum cover member 123 provided at both ends of the cartridge 100 in the Y direction.

[0027] As shown in Fig. 9, a coupling member 125 for transmitting a driving force to the photosensitive drum 101 is provided at one end of the photosensitive drum 101 in the Y direction. The coupling member 125 engages with a main body-side drum drive coupling 30 serving as a drum drive output unit of the apparatus main body 2, and the driving force of a drive motor (not shown) of the apparatus main body 2 is transmitted to the photosensitive drum 101, causing it to rotate in the direction of arrow A in Fig. 3. The photosensitive drum 101 also has a drum flange 124 at the other end in the Y direction. Bearings 126a and 127a, which support both ends of the charging roller 102 in the Y direction, are supported by the drum frame 121 so that the charging roller 102 can contact the photosensitive drum 101 and rotate following it (in the direction E in Fig. 3).

[0028] <Configuration of the development unit> As shown in FIGS. 3 and 8, the developing unit 150 includes a developing roller 103, a supply roller 104, a developing blade 156, a developing frame 1512 (developing container), and an agitating member 161. The longitudinal direction of the developing unit 150 is the direction of the rotation axis RA2 of the developing roller 103 (Y direction). The developing frame 1512 is formed of resin and includes a first frame 151 (first frame) and a second frame 152 (second frame). The first frame 151 and the second frame 152 have a first inner wall 151d and a second inner wall 152d, respectively. The first frame 151 and the second frame 152 are joined by ultrasonic welding or the like so that the first inner wall 151d and the second inner wall 152d form a toner storage chamber AC for storing toner and a developing chamber DC. The toner storage chamber AC and the developing chamber DC are collectively referred to as a storage space.

[0029] As shown in FIG. 1, the developing frame 1512 is provided with a developing opening 1512a (first opening) and a communication opening 151c (second opening). The toner storage chamber AC and the developing chamber DC are in communication with each other via the communication opening 151c. A supply roller 104 is provided in the developing chamber DC. The developing chamber DC is in communication with the outside of the developing frame 1512 via the developing opening 1512a. The developing opening 1512a is provided at the lower end of the developing frame 1512 when the cartridge 100 is in a detachable mounting position. The developing opening 1512a is formed by the first frame 151 and the second frame 152. The developing roller 103 is provided facing the developing opening 1512a. The toner stored in the toner storage chamber AC is supplied to the supply roller via the communication opening 151c. Furthermore, toner is supplied to the developing roller 103 via the supply roller 104, and the toner is carried by the developing roller 103. The developing frame 1512 further has a first bearing member 153 and a second bearing member 154 at one end and the other end of the developing roller 103 in the Y direction, respectively. Both ends of the developing roller 103 and the supply roller 104 are rotatably supported by the first bearing member 153 and the second bearing member 154. The developing frame 1512 (first frame 151) holds a developing blade 156 (regulating member) for regulating the thickness of the toner layer on the outer peripheral surface of the developing roller 103. The developing blade 156 includes an elastic member 156b, which is a sheet metal with a thickness of approximately 0.1 mm, and a support member 156a to which the elastic member 156b is fixed. The support member 156a has an L-shaped cross section perpendicular to the Y direction and is made of metal. The developing blade 156 is fixed to the developing frame 1512 (first frame 151) at two locations, one end and the other end in the Y direction, by fixing screws 156c.

[0030] A development drive input gear 159 for transmitting a driving force to the development unit 150 is provided on one end side of the development unit 150 in the Y direction. The development drive input gear 159 is provided with a coupling 159a that receives driving force from the coupling 40 of the apparatus main body 2, and the driving force of a drive motor (not shown) of the apparatus main body 2 is input to the development unit 150.

[0031] The driving force input to the developing unit 150 is transmitted to the developing roller gear 157, thereby rotating the developing roller 103 in the direction of arrow C in FIG. 3 , and to the toner conveying roller gear 158, thereby rotating the supply roller 104 in the direction of arrow D in FIG. 3 . Furthermore, the driving force is transmitted to the agitating gear 160, thereby rotating the agitating member 161 in the direction of arrow G in FIG. 3 , thereby agitating the toner in the toner storage chamber AC. The agitating member 161 has a rotating shaft 161a that can rotate about a rotation axis RA1 extending in the Y direction, and an agitating sheet 161b (conveying member) fixed to the rotating shaft 161a. The agitating sheet 161b is a sheet having one end, perpendicular to the rotation axis RA1, fixed to the rotating shaft 161a, and the other end, free end. The agitating sheet 161b agitates the toner stored in the toner storage chamber AC by rotating together with the rotating shaft 161a. A developing unit cover member 155 that supports and covers a developing drive input gear 159 is provided on one end side of the developing unit 150 in the Y direction.

[0032] <Assembling the drum unit and developing unit> Assembly of the drum unit 120 and the developing unit 150 will be described using FIG. 9. The drum unit 120 and the developing unit 150 are connected by a first drum cover member 122 and a second drum cover member 123 provided at both ends of the cartridge 100 in the Y direction. The first drum cover member 122 is provided with a developing unit support hole 122b for supporting the developing unit 150 so that it can swing (move). Similarly, the second drum cover member 123 is provided with a developing unit support hole 123b for supporting the developing unit 150 so that it can swing. Furthermore, the first drum cover member 122 and the second drum cover member 123 are provided with drum support holes 122a and 123a, respectively, for rotatably supporting the photosensitive drum 101. Here, at one end of the cartridge 100 in the Y direction, the outer diameter portion of the cylindrical portion 155a of the developing unit cover member 155 is fitted into the developing unit support hole 122b of the first drum cover member 122. At the other end side in the Y direction of the cartridge 100, the outer diameter portion of the cylindrical portion (not shown) of the second bearing member 154 is fitted into the developing roller support hole 123b of the second drum cover member 123. Furthermore, both ends in the Y direction of the photosensitive drum 101 are fitted into the drum support hole 122a of the first drum cover member 122 and the drum support hole 123a of the second drum cover member 123. Then, the first drum cover member 122 and the second drum cover member 123 are fixed to the drum unit 120 with screws, adhesive, or the like (not shown). As a result, the developing unit 150 is supported by the first drum cover member 122 and the second drum cover member 123 so as to be swingable relative to the drum unit 120 (photosensitive drum 101) in a direction in which the developing roller 103 approaches the photosensitive drum 101.

[0033] FIG. 10 shows the cartridge 100 in a state assembled by the above steps. Here, an imaginary line connecting the center of the developing support hole 122b of the first drum cover member 122 and the center of the developing support hole 123b of the second drum cover member 123 is taken as the swing axis SA. The cylindrical portion 155a of the developing cover member 155 on one end side is arranged coaxially with the coupling 159a (drive input member). In other words, the developing unit 150 is configured to receive driving force from the apparatus main body 2 along the swing axis SA. The developing unit 150 is supported so as to be swingable relative to the drum unit 120 around the swing axis SA.

[0034] <Detailed internal structure of the development unit> The detailed internal configuration of the developing unit will be described using FIGS. 1, 11, and 12. FIG. 1 is a main cross-sectional view of the developing unit 150 in this embodiment. As described above, the developing unit 150 is configured by joining two frames, a first frame 151 and a second frame 152. The agitating member 161 provided in the toner storage chamber AC of the developing unit 150 includes a rotating shaft 161a and an agitating sheet 161b. The agitating member 161 agitates the toner in the toner storage chamber AC. A sheet 171 is attached (fixed) to the lower end of the second frame 152 via double-sided tape. The sheet 171 abuts against the developing roller 103 at the developing opening 1512a so as to close the gap between the developing roller 103 and the second frame 152, thereby preventing toner leakage from the developing opening 1512a.

[0035] A first gripping portion 151a is provided on a first outer surface of the first frame 151 that is exposed to the outside of the cartridge 100. A second gripping portion 152a is provided on a second outer surface of the second frame 152 that is exposed to the outside of the cartridge 100. The first gripping portion 151a and the second gripping portion 152a are aligned in the X direction with the toner storage chamber AC between them.

[0036] The first grip portion 151a and the second grip portion 152a are a plurality of first protrusions and a plurality of second protrusions, respectively. In this embodiment, the plurality of first protrusions and the plurality of second protrusions are aligned at intervals in the Z direction and extend in the Y direction. The first grip portion 151a and the second grip portion 152a are not limited to this shape as long as they have a non-slip shape when the user places his / her fingers on the cartridge 100 (developing unit 150). For example, the first grip portion 151a and the second grip portion 152a may be recessed or have a textured outer surface.

[0037] 5, the user defines the posture of cartridge 100 when tray 20 is located at the outer position and cartridge 100 is supported by tray 20 as the mounted posture for attachment / detachment. The mounted posture for attachment / detachment is the posture of cartridge 100 in a state in which the user can remove cartridge 100. The user attaches / detaches cartridge 100 by grasping first grip portion 151a and second grip portion 152a of cartridge 100 in the mounted posture from the outside.

[0038] As shown in FIG. 1, the first frame 151 has a first protrusion 151b (first protrusion) protruding from the inner wall 151d in the X direction in the toner storage chamber AC and having a first tip surface 151b1 in the X direction. The second frame 152 has a second protrusion 152b (second protrusion) protruding from the inner wall 152d in the X direction in the toner storage chamber AC and having a second tip surface 152b1 in the X direction. The first protrusion 151b and the second protrusion 152b are aligned in the X direction (first direction). The tip surface 151b1 of the first protrusion 151b and the tip surface 152b1 of the second protrusion 152b are aligned in the X direction with a gap S therebetween. In this embodiment, the gap S is 0.35 mm. 11 and 12, the first protrusion 151b and the second protrusion 152b of this embodiment are a plurality of first ribs and a plurality of second ribs, respectively, aligned at intervals in the Y direction. The width of the first protrusion 151b and the second protrusion 152b in the Y direction is narrower than the width in the X direction. A space AC1 (FIG. 11) between the plurality of first ribs and a space AC2 (FIG. 12) between the plurality of second ribs form part of the toner storage chamber AC. Note that the first protrusion 151b and the second protrusion 152b may be at least a part of the plurality of first ribs and the plurality of second ribs aligned in the Y direction, respectively.

[0039] A toner filling port 151f is provided on the Y-direction end face of the first frame 151. To prevent the first protrusion 151b from interfering with the filling of toner when filling the toner, the first protrusion 151b and the toner filling port 151f are arranged so as not to overlap when viewed in the Y direction.

[0040] Here, the distance between the tip 161b1 of the agitation sheet 161b in an unbent state and the rotation axis RA1 of the rotating shaft 161a is defined as the rotation radius R. The rotation trajectory of the tip 161b1 of the agitation sheet 161b in an unbent state when the rotating shaft 161a rotates is defined as a virtual circle VC. The distance from the first portion 151b2 of the first protrusion 151b to the rotation axis RA1 and the distance from the second portion 152b2 of the second protrusion 152b to the rotation axis RA2 are both shorter than the rotation radius R. In other words, the first portion 151b2 of the first protrusion 151b and the second portion 152b2 of the second protrusion 152b are both located inside the virtual circle VC. In other words, the agitation sheet 161b is configured to bend as it abuts against the first portion 151b2 or the second portion 152b2 while the rotating shaft 161a rotates. The agitation sheet 161b is shaped so that the amount of deflection gradually changes as the rotation shaft 161a rotates, so as not to impede the rotation of the agitation sheet 161b when the rotation shaft 161a rotates. The distance between the third portion 151b3 of the first protrusion 151b and the rotation axis RA1 is greater than the rotation radius R. Therefore, the third portion 151b3 does not come into contact with the agitation sheet 161b even when the rotation shaft 161a rotates. When the cartridge 100 is new (unused) (as shipped from the factory), the initial rotation phase of the agitation sheet 161b is the phase in which the third portion 151b3 is present. This prevents creep deformation of the agitation sheet 161b. As shown in FIG. 1, when the cartridge 100 is in the installation position for installation and removal, both the first protrusion 151b and the second protrusion 152b are located above the rotation axis RA1. The developing roller 103 is provided below the rotation axis RA1. The first protrusion 151b and the second protrusion 152b are provided at the upper end of the developing frame 1512 when the cartridge 100 is in the attachment / detachment posture. The first protrusion 151b and the second protrusion 152b are provided on the opposite side of the rotation axis RA1 from the developing roller 103 in a cross section perpendicular to the rotation axis RA1.

[0041] <Structure to prevent deformation of the development unit> 13(a), 13(b), and 1, a characteristic structure for suppressing deformation of the developing frame 1512 of the developing unit 150 will be described. As described above, a user replaces the developing unit by grasping the gripping portions 151a and 152a provided on the first frame 151 and the second frame 152 of the developing frame 1512, respectively. When a user grasps the cartridge 100, a gripping force F is generated, as shown in FIG. 14(a), and each frame is deformed as shown by the solid lines (the broken lines represent the state before deformation). When the developing frame 1512 is deformed as shown in FIG. 14(a), the internal volume of the developing frame 1512 decreases, causing an increase in internal pressure and possibly causing toner to leak to the outside. In particular, in a configuration like this embodiment in which the developing opening 1512a (FIG. 1) is made up of the first frame 151 and the second frame 152, and the gap between the second frame 152 and the developing roller 103 is sealed with the sheet 171, there is a possibility that toner leakage may occur due to deformation of the developing frame 1512. This is because the relative positions of the first frame 151 and the second frame 152 may change due to elastic deformation of the developing frame 1512 caused by the user gripping the grip portions 151a and 152a, which may weaken the contact pressure of the sheet 171 against the developing roller 103 or cause the sheet 171 to separate from the developing roller 103. For this reason, conventionally, measures have been taken, such as increasing the thickness of the sheet 171 to increase the contact pressure between the sheet 171 and the developing roller 103, or providing a deaeration filter member or the like in the developing frame 1512 to reduce the internal pressure.

[0042] 14(b), by providing a first protrusion 151b and a second protrusion 152b facing each other across a gap S on each of the first frame 151 and the second frame 152, it is possible to suppress deformation of the developing frame 1512 when a gripping force F is generated. When the gripping force F is generated and the first frame 151 and the second frame 152 attempt to deform in a direction toward each other, the tip surface 151b1 of the first protrusion 151b and the tip surface 152b1 of the second protrusion 152b come into contact with each other, thereby suppressing the deformation of the first frame 151 and the second frame 152 from becoming too large. The gap S is set so that when an external force presses the developing frame 1512 in the X direction so that the first and second frames 151 and 152 approach each other, the developing frame 1512 elastically deforms, bringing the first end surface 151b1 and the second end surface 152b1 into contact with each other. As described above, the gap S in this embodiment is set to 0.35 mm. The gap S is preferably 0.20 mm or greater and 1.45 mm or less. This configuration in this embodiment reduces the need to increase the contact pressure between the sheet 171 and the developing roller 103 or to provide a deaeration filter member or the like on the developing frame 1512. The first protrusion 151b and the second protrusion 152b are provided on the backsides of the first gripping portion 151a and the second gripping portion 152a, respectively. In other words, the first protrusion 151b and the second protrusion 152b are provided so as to be aligned with the first gripping portion 151a and the second gripping portion 152a, respectively, in the X direction, thereby minimizing deformation of the developing frame 1512.

[0043] As described above, according to this embodiment, it is possible to suppress deformation of the developing frame when the user grips the cartridge, and to prevent toner from leaking from the developing frame to the outside. [Explanation of symbols]

[0044] 1. Image forming device 2. Device body 100 cartridges 101 Photosensitive drum 103 Developing roller 104 Supply roller 121 Drum frame 150 Development Unit 151 First Frame 152 Second Frame 161 Stirring member 161a Rotating shaft 161b Mixing sheet 151b First protrusion 151b1 First tip surface 152b second protrusion 152b1 Second tip surface 1512 Developing frame 1512a aperture AC Toner Containment Chamber R: Radius of rotation of stirring member RA1 Rotation axis of the stirring member S Gap VR Virtual Circle

Claims

1. In the developing cartridge, A developer container, a first frame including a first inner wall and a first protrusion protruding from the first inner wall; a second frame including a second inner wall that defines a toner storage space together with the first inner wall and a second protrusion that protrudes from the second inner wall, the second frame being aligned with the first frame in a first direction; and a developing container provided with an opening communicating with the storage space; a developing roller provided to face the opening; a stirring member provided in the storage space, the stirring member including: a rotating shaft rotatable about a rotation axis extending in a direction intersecting the first direction; and a sheet having one end and the other end in a direction perpendicular to the rotation axis as a fixed end fixed to the rotating shaft and a free end, respectively; Equipped with at least a part of the first protrusion and at least a part of the second protrusion are located inside an imaginary circle that is a rotation locus of a tip of the free end of the sheet in an undeflected state when the rotation shaft is rotated, in a cross section perpendicular to the rotation axis, a first tip surface of the first protruding portion in the first direction and a second tip surface of the second protruding portion in the first direction face each other across a gap in the cross section, the gap is set so that, when the developing container is pressed by an external force in a direction in which the first frame and the second frame approach each other in the first direction, the developing container is elastically deformed and the first tip surface and the second tip surface come into contact with each other. A developing cartridge characterized by:

2. the first frame includes a plurality of first ribs protruding from the first inner wall and spaced apart from one another in the direction of the rotation axis, the second frame includes a plurality of second ribs protruding from the first inner wall and spaced apart from one another in the direction of the rotation axis, the first protrusion is one of the plurality of first ribs, The second protrusion is at least one of the plurality of second ribs.

2. The developing cartridge according to claim 1, wherein the developing cartridge is a developing cartridge having a plurality of developing members.

3. the plurality of first ribs and the plurality of second ribs have a width in the direction of the rotation axis narrower than a width in the first direction; 3. The developing cartridge according to claim 2.

4. a first protrusion is provided on a first outer surface of the first frame that is exposed to the outside of the developing cartridge; a second protrusion is provided on a second outer surface of the second frame that is exposed to the outside of the developing cartridge; the first protrusion is provided so as to be aligned with the plurality of first ribs in the first direction in a cross section perpendicular to the rotation axis, the second protrusion is provided so as to be aligned with the plurality of second ribs in the first direction in a cross section perpendicular to the rotation axis.

3. The developing cartridge according to claim 2, wherein:

5. In a cross section perpendicular to the rotation axis when the developing cartridge is mounted in the main body of an image forming apparatus, the first protrusion and the second protrusion are provided above the rotation axis, The developing roller is provided below the rotation axis.

2. The developing cartridge according to claim 1, wherein the developing cartridge is a developing cartridge having a plurality of developing members.

6. 6. The developing cartridge according to claim 5, wherein the first protrusion and the second protrusion are provided at an upper end of the developing container when the developing cartridge is in the orientation.

7. the first protruding portion and the second protruding portion are provided on the opposite side of the rotation axis from the developing roller in a cross section perpendicular to the rotation axis; 2. The developing cartridge according to claim 1, wherein the developing cartridge is a developing cartridge having a plurality of developing members.

8. the first protrusion has a portion that is outside the imaginary circle in a cross section perpendicular to the rotation axis; 2. The developing cartridge according to claim 1, wherein the developing cartridge is a developing cartridge having a plurality of developing members.

9. a photosensitive drum configured to receive toner from the developing roller; a drum frame that rotatably supports the photosensitive drum; and The developing container is rotatably supporting the developing roller; the developing container is supported by the drum frame so as to be swingable relative to the drum frame in a direction in which the developing roller approaches the photosensitive drum; 2. The developing cartridge according to claim 1, wherein the developing cartridge is a developing cartridge having a plurality of developing members.

10. a supply roller configured to supply toner to the developing roller, the supply roller being in contact with the developing roller; When the opening is a first opening, the first frame has a second opening, The supply roller is provided to face the second opening.

2. The developing cartridge according to claim 1, wherein the developing cartridge is a developing cartridge having a plurality of developing members.

11. the opening is defined by the first frame and the second frame, a sheet fixed to the second frame so as to close a gap between the second frame and the developing roller; 2. The developing cartridge according to claim 1, wherein the developing cartridge is a developing cartridge having a plurality of developing members.

12. a regulating member for regulating the thickness of the toner layer on the developing roller; 12. A developing cartridge according to claim 11, wherein the regulating member is fixed to the first frame.

13. In the developing cartridge, A developing container formed of resin, a first frame including a first inner wall and a first protrusion protruding from the first inner wall; a second frame including a second inner wall that defines a toner storage space together with the first inner wall and a second protrusion that protrudes from the second inner wall, the second frame being aligned with the first frame in a first direction; and a developing container provided with an opening communicating with the storage space; a developing roller provided to face the opening; a stirring member provided in the storage space, the stirring member including: a rotating shaft rotatable about a rotation axis extending in a direction intersecting the first direction; and a sheet having one end and the other end in a direction perpendicular to the rotation axis as a fixed end fixed to the rotating shaft and a free end, respectively; Equipped with at least a part of the first protrusion and at least a part of the second protrusion are located inside an imaginary circle that is a rotation locus of a tip of the free end of the sheet in an undeflected state when the rotation shaft is rotated, in a cross section perpendicular to the rotation axis, a first tip surface of the first protruding portion in the first direction and a second tip surface of the second protruding portion in the first direction face each other across a gap in the cross section, The gap is equal to or greater than 0.20 mm and equal to or less than 1.45 mm. A developing cartridge characterized by:

14. the first frame includes a plurality of first ribs protruding from the first inner wall and spaced apart from one another in the direction of the rotation axis, the second frame includes a plurality of second ribs protruding from the first inner wall and spaced apart from one another in the direction of the rotation axis, the first protrusion is one of the plurality of first ribs, The second protrusion is at least one of the plurality of second ribs.

14. The developing cartridge according to claim 13.

15. the plurality of first ribs and the plurality of second ribs have a width in the direction of the rotation axis narrower than a width in the first direction; 15. The developing cartridge according to claim 14.

16. a first protrusion is provided on a first outer surface of the first frame that is exposed to the outside of the developing cartridge; a second protrusion is provided on a second outer surface of the second frame that is exposed to the outside of the developing cartridge; the first protrusion is provided so as to be aligned with the plurality of first ribs in the first direction in a cross section perpendicular to the rotation axis, the second protrusion is provided so as to be aligned with the plurality of second ribs in the first direction in a cross section perpendicular to the rotation axis.

15. The developing cartridge according to claim 14, wherein:

17. In a cross section perpendicular to the rotation axis when the developing cartridge is mounted in the main body of an image forming apparatus, the first protrusion and the second protrusion are provided above the rotation axis, The developing roller is provided below the rotation axis.

14. The developing cartridge according to claim 13.

18. 18. The developing cartridge according to claim 17, wherein the first protrusion and the second protrusion are provided at an upper end of the developing container when the developing cartridge is in the orientation.

19. the first protruding portion and the second protruding portion are provided on the opposite side of the rotation axis from the developing roller in a cross section perpendicular to the rotation axis; 14. The developing cartridge according to claim 13.

20. the first protrusion has a portion that is outside the imaginary circle in a cross section perpendicular to the rotation axis; 14. The developing cartridge according to claim 13.

21. a photosensitive drum configured to receive toner from the developing roller; a drum frame that rotatably supports the photosensitive drum; and The developing container is rotatably supporting the developing roller; the developing container is supported by the drum frame so as to be swingable relative to the drum frame in a direction in which the developing roller approaches the photosensitive drum; 14. The developing cartridge according to claim 13.

22. a supply roller configured to supply toner to the developing roller, the supply roller being in contact with the developing roller; When the opening is a first opening, the first frame has a second opening, The supply roller is provided to face the second opening.

14. The developing cartridge according to claim 13.

23. the opening is defined by the first frame and the second frame, a sheet fixed to the second frame so as to close a gap between the second frame and the developing roller; 14. The developing cartridge according to claim 13.

24. a regulating member for regulating the thickness of the toner layer on the developing roller; 24. A developing cartridge according to claim 23, wherein the regulating member is fixed to the first frame.

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