Cartridge

Abstract

To improve toner circulation performance in a configuration in which a developing chamber is disposed below a developer accommodating chamber.SOLUTION: In a posture in which the developing device is mounted on an image forming apparatus and used for image formation, a developing chamber is provided below a containing chamber, at least a part of an opening is located above a supply roller, and a stirring shaft is located above the opening. A second stirring sheet member is provided on the opposite side of a virtual line passing through the rotation center of the stirring shaft from a side where a first stirring sheet member is provided. Both the first stirring sheet member and the second stirring sheet member have lengths such that their respective other ends can reach the opening when the stirring shaft rotates.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cartridge for an image forming apparatus used to form an image on a recording medium. [Background technology]

[0002] Conventionally, image forming apparatuses using an electrophotographic image forming process have adopted a cartridge system in which cartridges such as developing cartridges and process cartridges can be attached to and detached from the main body of the image forming apparatus for use. One example of a developing device in such a cartridge is a developing device that is divided into a developing chamber having a developing roller and a developer supply roller, and a developer storage chamber that stores developer, and has an opening for connecting the developing chamber and the developer storage chamber.

[0003] Patent Document 1 proposes a configuration in which a development chamber is disposed below a developer storage chamber, and a stirring member disposed inside the developer storage chamber transports the developer to the development chamber. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2022-130369 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention is a further development of the conventional configuration, and aims to improve the circulation performance of toner in a configuration in which a developer storage chamber is disposed above a development chamber. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the cartridge of the present application is a cartridge that is mounted on an image forming apparatus and used to form images, and includes: a storage chamber that stores toner; a rotatable developing roller that carries toner; a rotatable supply roller that supplies toner to the developing roller; a developing chamber that communicates with the storage chamber through an opening and in which the developing roller and the supply roller are disposed; and an agitating member that is provided inside the storage chamber and agitates the toner, the agitating member including a rotating agitating shaft; a first agitating sheet member that is sheet-like and has one end fixed to the agitating shaft and the other end free; and a second agitating sheet member that is sheet-like and has one end fixed to the agitating shaft and the other end free. and a second agitation sheet member having a shape similar to that of a developing chamber, and when viewed from the direction of the rotation axis of the agitation shaft, in an attitude in which the developing chamber is attached to the image forming apparatus and used for forming an image, the developing chamber is provided below the storage chamber, at least a portion of the opening is located above the supply roller, the agitation shaft is located above the opening, the second agitation sheet member is provided on the opposite side of an imaginary line passing through the rotation center of the agitation shaft to the side on which the first agitation sheet member is provided, and the lengths of the first agitation sheet member and the second agitation sheet member are both long enough that the other ends of the first agitation sheet member can reach the opening when the agitation shaft rotates. [Effects of the Invention]

[0007] According to the present invention, in a configuration in which the development chamber is disposed below the developer storage chamber, the circulation performance of the toner can be improved. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a cross-sectional view illustrating the configuration of a developing unit according to the present invention. [Figure 2] 1 is a schematic cross-sectional view of an image forming apparatus according to the present invention. [Figure 3] FIG. 2 is a cross-sectional view of a process cartridge according to the present invention. [Figure 4] 1 is a cross-sectional view of an image forming apparatus according to the present invention. [Figure 5]1 is a cross-sectional view of an image forming apparatus according to the present invention. [Figure 6] 1 is a cross-sectional view of an image forming apparatus according to the present invention. [Figure 7] FIG. 2 is an exploded perspective view of the drum unit according to the present invention. [Figure 8] FIG. 1 is an exploded perspective view of a development unit according to the present invention; [Figure 9] FIG. 2 is an assembled perspective view of the process cartridge according to the present invention. [Figure 10] FIG. 2 is a perspective view of a process cartridge according to the present invention. [Figure 11] FIG. 2 is a diagram illustrating a first frame according to the present invention. [Figure 12] FIG. 2 is a diagram illustrating a second frame according to the present invention. [Figure 13] 3A and 3B are diagrams illustrating a stirring member according to the present invention. [Figure 14] 5A and 5B are diagrams illustrating the state of toner inside a developing unit according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0010] However, the functions, materials, shapes, dimensions, and relative arrangements of the components described in these examples should be changed as appropriate depending on the configuration of the device to which the invention is applied and various conditions, and unless otherwise specified, it is not intended to limit the scope of this invention to these alone.

[0011] First Embodiment A first embodiment of the present invention will be described below with reference to the drawings. In the first embodiment, an image forming apparatus to which four process cartridges can be detachably attached is exemplified. However, the number of process cartridges attached to the image forming apparatus is not limited to this. It can be set appropriately as needed.

[0012] In the embodiment described below, a laser beam printer is exemplified as one aspect of the image forming apparatus.

[0013] (Schematic configuration of image forming apparatus) The overall configuration of an electrophotographic image forming apparatus 1 (hereinafter referred to as 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 cross-sectional view of a process cartridge 100.

[0014] This 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 process cartridge type, and a process cartridge 100 is removably attached to the image forming apparatus main body 2, and a color image is formed on the recording medium 3.

[0015] 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.

[0016] The drive side of the process cartridge 100 is the side where the drum coupling member (photosensitive member coupling member) described later is arranged when viewed in the axial direction of the photosensitive drum, and is the side where the development coupling member described later is arranged when viewed in the axial direction of the development roller (developing member).

[0017] In the image forming apparatus main body 2, first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) are arranged in a substantially horizontal direction.

[0018] The first to fourth process cartridges 100 (100Y, 100M, 100C, 100K) each have the same electrophotographic process mechanism, but differ in the color and amount of developer (hereinafter referred to as toner). Therefore, in the following, unless a particular distinction is required, the suffixes Y to K will be omitted and the process cartridges will be described collectively.

[0019] A rotational driving force is transmitted to the first to fourth process cartridges 100 from a driving output section (details will be described later) of the image forming apparatus main body 2, and bias voltages (charging bias, developing bias, electrostatic residual detection bias, etc.) are supplied from contacts of the image forming apparatus main body 2 (not shown).

[0020] 3, the process cartridge 100 of this embodiment has a photosensitive drum 101 and a drum unit 120 equipped with charging means as process means acting on the photosensitive drum 101. Here, the drum unit 120 may have not only the charging means but also cleaning means as process means.

[0021] The process cartridge 100 also has a developing unit 150 equipped with a developing means for developing the electrostatic latent image on the photosensitive drum 101 .

[0022] The drum unit 120 and the developing unit 150 are coupled to each other. A more specific configuration of the process cartridge 100 will be described later.

[0023] In FIG. 2, the first process cartridge 100Y accommodates yellow (Y) toner in the developing frame, and forms a yellow toner image on the surface of the photosensitive drum 101.

[0024] Similarly, the second process cartridge 100M accommodates magenta (M) toner in the developing frame, and forms a magenta toner image on the surface of the photosensitive drum 101.

[0025] The third process cartridge 100C accommodates cyan (C) toner in the developing frame, and forms a cyan toner image on the surface of the photosensitive drum 101.

[0026] The fourth process cartridge 100K accommodates black (K) toner in the developing frame, and forms a black toner image on the surface of the photosensitive drum 101.

[0027] 2, a laser scanner unit 11 serving as an exposure means is provided above the first to fourth process cartridges 100. 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 process cartridge 100 and scans and exposes the surface of the photosensitive drum 101.

[0028] An intermediate transfer unit 5 serving as a transfer member is provided below the first to fourth process cartridges 100. This intermediate transfer unit 5 has a drive roller 5e and a tension roller 5b, and a flexible transfer belt 5a is stretched over them.

[0029] The lower surface of the photosensitive drum 101 of each of the first to fourth process cartridges 100 contacts the upper surface of the transfer belt 5a. This contact area is the primary transfer portion. A primary transfer roller 5d is provided on the inner side of the transfer belt 5a, facing the photosensitive drum 101.

[0030] A secondary transfer roller 6 is brought into contact with the drive roller 5e via the transfer belt 5a. The contact area between the transfer belt 5a and the secondary transfer roller 6 is the secondary transfer portion.

[0031] Below the intermediate transfer unit 5, there is provided a feeding unit 4 having a paper feed tray 4a in which recording media 3 are stacked and accommodated, and a paper feed roller 4b.

[0032] A fixing device 7 and a paper discharge device 8 are provided in the upper right corner of the image forming apparatus main body 2 in FIG.

[0033] 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 then discharged onto a paper discharge tray 9 .

[0034] (Image formation operation) The image forming operation will be described with reference to Figures 2 and 3. The operation for forming a full-color image is as follows.

[0035] The photosensitive drum 101 of each of the first to fourth process cartridges 100 is rotationally driven at a predetermined speed (the direction of arrow A in FIG. 3). The transfer belt 5a is also rotationally driven in the forward direction (the direction of arrow B in FIG. 2) relative to the rotation of the photosensitive drum 101 at a speed corresponding to the speed of the photosensitive drum 101.

[0036] The laser scanner unit 11 is driven. In synchronization with the driving of the laser scanner unit 11, the charging roller 102 in each process 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.

[0037] 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 (the direction of arrow C in FIG. 3) relative to the rotation of the photosensitive drum 101.

[0038] By the electrophotographic image forming process operation as described above, a yellow toner image corresponding to the yellow component of the full-color image is formed on the photosensitive drum 101 of the first process cartridge 100Y as shown in Figure 2. Then, the toner image is primarily transferred onto the transfer belt 5a.

[0039] 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 process cartridge 100M. Then, this toner image is primarily transferred onto the transfer belt 5a, superimposed on the yellow toner image already transferred onto the transfer belt 5a.

[0040] 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 process cartridge 100C. Then, this toner image is primarily transferred onto the transfer belt 5a, superimposed on the yellow and magenta toner images already transferred onto the transfer belt 5a.

[0041] 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 process cartridge 100K. Then, this toner image is primarily transferred onto the transfer belt 5a, superimposed on the yellow, magenta, and cyan toner images already transferred onto the transfer belt 5a.

[0042] In this way, an unfixed full-color toner image of four colors, yellow, magenta, cyan, and black, is formed on the transfer belt 5a.

[0043] 2, the recording media 3 are separated and fed one by one at a predetermined control timing, and then transported to a secondary transfer section, which is a contact point between the secondary transfer roller 6 and the transfer belt 5a, at a predetermined control timing.

[0044] As a result, the four-color superimposed toner image on the transfer belt 5a is transferred onto the surface of the recording medium 3 in a batch in sequence while the recording medium 3 is being transported through the secondary transfer portion.

[0045] The structure of the image forming apparatus main body will be described in more detail below.

[0046] (Process cartridge installation / removal configuration overview) The cartridge tray 20 (hereinafter referred to as the tray 20) that supports the process cartridge 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 image forming 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 image forming apparatus main body 2, and the process cartridge 100 housed inside 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 image forming apparatus main body 2, and the process cartridge 100 removed from the tray 20.

[0047] As shown in FIGS. 4 and 5, the tray 20 is movable in the direction of arrow X1 (pushing direction) and the direction of arrow X2 (pulling direction), which are substantially horizontal directions, relative to the image forming apparatus main body 2 installed on a horizontal surface. That is, the tray 20 is provided so that it can be pulled out and pushed into the image forming apparatus main body 2. When the image forming apparatus main body 2 is installed on a horizontal surface in this manner, the tray 20 is configured to be movable in a substantially horizontal direction. Here, the state in which the tray 20 is positioned inside the image forming apparatus main body 2 with the front door 10 open (the state in FIG. 4) will be referred to as the inside position. Furthermore, the state in which the tray 20 is positioned outside the image forming apparatus main body 2 (the state in FIG. 5) will be referred to as the outside position. In this way, in the inside state in which the tray 20 is positioned inside and the outside state in which the tray 20 is positioned outside, the photosensitive drum 101 and the transfer belt 5a are spaced apart.

[0048] The tray 20 also has a mounting portion 20a at its outer position, into which the first process cartridge 100Y can be detachably attached, as shown in FIG. 6. (The tray 20 also has similar mounting portions 20a into which the second to fourth process cartridges 100M, 100C, and 100K can be detachably attached.) The process cartridge 100, while attached to the mounting portion 20a, moves toward the inside of the image forming apparatus main body 2 as the tray 20 moves. 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 intermediate transfer belt 5a contact each other) (the state shown in FIG. 4). When the front door 10 is opened, the intermediate transfer unit 5 is lowered in the direction of arrow Z2, separating the photosensitive drum 101 and the intermediate transfer belt 5a.

[0049] As described above, the tray 20 allows multiple process cartridges 100 to be moved together to a position inside the image forming apparatus main body 2 where image formation is possible, and also allows them to be pulled out together to the outside of the image forming apparatus main body 2.

[0050] (Overall structure of the process cartridge) The structure of the process cartridge will be described with reference to FIGS.

[0051] Fig. 7 is an exploded perspective view of the drum unit 120. Fig. 8 is an exploded perspective view of the development unit 150. Fig. 9 is an assembled perspective view of the process cartridge 100 as seen from the drive side, which is one end side in the axial direction of the photosensitive drum 101. Fig. 10 is a perspective view of the process cartridge 100 as seen from the drive side.

[0052] The process cartridge 100 includes a photosensitive drum 101 and process means that act on the photosensitive drum 101. The process means includes a charging roller 102 as charging means that charges the photosensitive drum 101, and a developing roller 103 as developing means that develops the latent image formed on the photosensitive drum 101. The process cartridge 100 is divided into a drum unit 120 and a developing unit 150.

[0053] In the following description, the longitudinal direction Y of the drum unit 120 and the developing unit 150 is a direction substantially parallel to the rotation axis a of the photosensitive drum 101 (FIG. 9).

[0054] <Drum unit configuration> As shown in Figure 7, the drum unit 120 is made up 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 against the photosensitive drum 101 (in the direction of arrow F in Figure 3) by pressure springs 126b and 127b. The photosensitive drum 101 is rotatably supported by a driving-side cartridge cover member 122 and a non-driving-side cartridge cover member 123, which are provided at both ends of the process cartridge 100 in the longitudinal direction.

[0055] 9, a coupling member 125 for transmitting a driving force to the photosensitive drum 101 is provided on one end side in the longitudinal direction of the photosensitive drum 101. The coupling member 125 engages with a main body side drum drive coupling 30 serving as a drum drive output part of the image forming apparatus main body 2, and the driving force of a drive motor (not shown) of the image forming apparatus main body 2 is transmitted to the photosensitive drum 101, causing it to rotate in the direction of arrow A in FIG. 3. In addition, the photosensitive drum 101 has a drum flange 124 on the other end side in the longitudinal direction.

[0056] As shown in FIG. 7, the driving side charging roller bearing 126a and the non-driving side charging roller bearing 127a that support the charging roller 102 are supported by the drum frame 121 so that the charging roller 102 can contact the photosensitive drum 101 and rotate in the direction of arrow E in FIG. 3.

[0057] (Configuration of the development unit) As shown in FIG. 3, the developing unit 150 is made up of a developing roller 103, a developer supplying roller 104, a developing blade 156, a developing frame, and the like.

[0058] The developing frame is made up of a first developing frame 151 and a second developing frame 152. The first developing frame 151 and the second developing frame 152 are joined by ultrasonic welding or the like. The developing frame has a toner storage section (storage chamber) 162 that stores toner to be supplied to the developing roller 103.

[0059] As shown in FIG. 8, the developing frame rotatably supports the developing roller 103 and the developer supply roller 104 via a drive side bearing 153 and a non-drive side bearing 154, and holds a developing blade 156 that regulates the thickness of the toner layer carried on the circumferential surface of the developing roller 103.

[0060] The developing blade 156 is made by attaching an elastic member 156b, which is a sheet metal with a thickness of about 0.1 mm, to a supporting member 156a, which is a metal material with an L-shaped cross section, by welding, etc. The developing blade 156 is attached to the developing frame body at two points, one end side and the other end side in the longitudinal direction, with fixing screws 156c.

[0061] A development drive input gear 159 for transmitting a driving force to the development unit 150 is provided on one end side in the longitudinal direction of the development unit 150. The development drive input gear 159 is provided with a development input coupling portion 159a that receives driving force from the main body side development drive coupling 40 of the image forming apparatus main body 2, and the driving force of a drive motor (not shown) of the image forming apparatus main body 2 is input to the development unit 150 via the development input coupling portion 159a.

[0062] The driving force input to the developing unit 150 is transmitted to the developing roller gear 157, causing the developing roller 103 to rotate in the direction of arrow C in Fig. 3, and is transmitted to the developer supply roller gear 158, causing the developer supply roller 104 to rotate in the direction of arrow D in Fig. 3. In addition, the driving force is transmitted to the stirring gear 160, causing the stirring member 161 to rotate in the direction of arrow G in Fig. 3, stirring the toner contained in the toner container 162.

[0063] As shown in FIG. 3, the agitation member 161 has a rotation shaft 161a parallel to the rotation axis direction of the developing roller 103, and a first agitation sheet (first agitation sheet member) 161b and a second agitation sheet (second agitation sheet member) 161c, which are flexible sheet conveying members. One end of each agitation sheet is attached to a fixed surface (first fixed surface, second fixed surface) of the rotation shaft 161a, and the other end of each agitation sheet is a free end. As the rotation shaft 161a rotates, the agitation sheets also rotate, thereby agitating the toner. In addition, a sealing member 163 is attached to the first agitation sheet 161b via double-sided tape, and in the shipping state, the developing opening 151a is sealed by the sealing member 163. The developing opening 151a is an opening that connects the developing chamber 164 and the toner storage section 162.

[0064] The sealing member 163 is peeled off from the developing opening as the agitating member 161 rotates. As shown in Figure 8, a developing device cover member 155 that supports and covers the developing drive input gear 159 is provided on one longitudinal end side of the developing unit 150.

[0065] (Assembly of drum unit and developing unit) The assembly of the drum unit 120 and the developing unit 150 will be described using Figure 9. The drum unit 120 and the developing unit 150 are connected by a drive-side cartridge cover member 122 and a non-moving-side cartridge cover member 123, which are provided at both longitudinal ends of the process cartridge 100. The drive-side cartridge cover member 122, which is provided at one longitudinal end of the process cartridge 100, is provided with a developing unit support hole 122b for supporting the developing unit 150 so that it can swing (move). Similarly, the non-drive-side cartridge cover member 123, which is provided at the other longitudinal end of the process cartridge 100, is provided with a developing unit support hole 123b for supporting the developing unit 150 so that it can swing. Furthermore, the drive-side cartridge cover member 122 and the non-moving-side cartridge cover member 123 are provided with drum support holes 122a and 123a, respectively, for rotatably supporting the photosensitive drum 101. Here, at one end, the outer diameter portion of the cylindrical portion 155a of the developing cover member 155 is fitted into the developing unit support hole 122b of the driving side cartridge cover member 122. At the other end, the outer diameter portion of the cylindrical portion (not shown) of the non-driving side bearing 154 is fitted into the developing unit support hole 123b of the non-moving side cartridge cover member 123. Furthermore, both longitudinal ends of the photosensitive drum 101 are fitted into the drum support hole 122a of the driving side cartridge cover member 122 and the drum support hole 123a of the non-moving side cartridge cover member 123. Then, the driving side cartridge cover member 122 and the non-moving side cartridge cover member 123 are fixed to the drum unit 120 with screws, adhesive, etc. (not shown). As a result, the developing unit 150 is rotatably supported relative to the drum unit 120 (photosensitive drum 101) by the driving side cartridge cover member 122 and the non-moving side cartridge cover member 123, and the developing roller 103 can be positioned to act on the photosensitive drum 101 during image formation.

[0066] The drum unit 120 and the developing unit 150 are assembled through the above steps and integrally formed as the process cartridge 100, as shown in FIG.

[0067] The axis connecting the center of the developing unit support hole 122b of the driving-side cartridge cover member 122 and the center of the developing unit support hole 123b of the non-moving-side cartridge cover member 123 is referred to as the swing axis b. Here, the cylindrical portion 155a of the developing unit cover member 155 on one end side is coaxial with the developing input coupling 159a. In other words, the developing unit 150 is configured to receive driving force from the image forming apparatus main body 2 at this swing axis b. The developing unit 150 is also supported rotatably about the swing axis b.

[0068] (Details of the internal structure of the development unit) Next, the internal structure of the developing unit will be described in detail with reference to FIGS. 1, 11, 12, and 13. FIG.

[0069] FIG. 1 is a principal cross-sectional view of the developing unit 150 in this embodiment. As described above, the developing unit 150 is composed of two frames, a first frame 151 and a second frame 152, joined together. An agitating member 161 is provided in the center of the developing unit 150 and agitates the developer at a constant speed. As shown in FIG. 13, the agitating member 161 is composed of a rotating agitating shaft 161a, a first agitating sheet 161b, and a second agitating sheet 161c. When new, a sealing member 163 is attached to the tip of the first agitating sheet 161b via an attachment means such as double-sided tape.

[0070] The first agitation sheet 161b and the second agitation sheet 161c are fixed at positions that are out of phase with each other by approximately 180 degrees relative to the agitation shaft 161a by thermally caulking the caulking bosses 161d.

[0071] The thermal crimping method is a processing method in which heat is applied to soften the material, and then the material is clamped with a tool and crushed by pressure. Therefore, when clamping and pressurizing the crimping boss 161d, it is desirable that both of the opposing surfaces are flat. In other words, it is desirable that the fixing surfaces (first fixing surface, second fixing surface) to which the first stirring sheet 161b and the second stirring sheet 161c are attached, and the opposite surface that corresponds to the fixing surfaces and is simultaneously pressed during thermal crimping, are also flat.

[0072] Furthermore, since the agitating member 161 is a rotating body that rotates around the agitating shaft 161a, it is preferable that the agitating member 161 be rotationally symmetrical with respect to the agitating shaft 161a, which is the axis of rotation, in order to stabilize the rotation.

[0073] That is, the second stirring sheet 161c is configured to be provided on the opposite side of the first stirring sheet 161b with respect to an imaginary line that passes through the center of rotation of the stirring shaft 161a and is perpendicular to the fixing surface to which the first or second stirring sheet is fixed.

[0074] The first agitation sheet 161b and the second agitation sheet 161c are typically made of a resin such as polycarbonate (PC) or polyphenylene sulfide (PPS) with a thickness of 50 μm to 200 μm, with the shape and material selected to achieve the required agitation, circulation, and durability. In this embodiment, a PC sheet with a thickness of 130 μm to 180 μm is used, and the reaction force of the sheet is adjusted by the shape of the agitation shaft 161a, such as by separating the ridge of the agitation shaft 161a from the crimped boss 161d, thereby achieving both performance characteristics. The sheet length (short side) in the cross section of FIG. 1 is set to a value that realizes the rotation radius R of the agitation member shown in FIG. 1 and is set to penetrate into the developing opening 151a and parts of the first and second frames 151 and 152. "Intrusion" refers to, for example, reaching a position where one component, such as a sheet, would overlap the other component if it were not deformed during rotation or other movement. In reality, after one part comes into contact with the other part, the part with lower rigidity bends and deforms. Also, the sheet length (long side) in the longitudinal direction of the developing unit 150 (the direction perpendicular to the paper surface in FIG. 1) is set to be longer than the developing opening 151a from the viewpoint of circulation.

[0075] The sealing member does not need to have the rigidity required to stir the toner, so the thickness of the sealing member is 40 to 50 μm, which is equal to or less than the thicknesses of the first stirring sheet 161b and the second stirring sheet 161c. The sealing member is preferably made of polyethylene terephthalate (PET), which has a lower flexural modulus than the first stirring sheet 161b and the second stirring sheet 161c.

[0076] The sealing member is a member that closes the developing opening 151a, and as described above, is attached to the tip of the first agitation sheet 161b via an attachment means such as double-sided tape. Therefore, the width of the sealing member in the rotational axis direction of the agitation shaft should be larger than the developing opening 151a and narrower than the width of the first agitation sheet 161b. The width of the sealing member in the rotational axis direction of the agitation shaft should be shorter than the length of the double-sided tape so that there is no portion that is not attached to the double-sided tape.

[0077] Next, the configuration of the first frame body 151 and the second frame body 152 will be described with reference to FIGS.

[0078] Each frame is provided with a first guide rib 166 and a second guide rib 167. As shown in the figure, each guide rib is arranged at multiple locations along the longitudinal direction, and serves to partially penetrate into the agitation sheet to guide the agitation member 161 as it rotates.

[0079] 11, opening-crossing ribs 151b are provided at multiple locations along the length of the developing opening 151a of the first frame 151. If the first agitating sheet 161b and the second agitating sheet 161c come into contact with the developer supply roller 104, image defects may occur. Therefore, the opening-crossing ribs 151b are provided to prevent the first agitating sheet 161b and the second agitating sheet 161c from entering the inside of the developing chamber 164.

[0080] Next, the circulation of toner within the developing unit 150 will be described with reference to FIG.

[0081] In the developing chamber 164, the developing roller 103 and the developer supply roller 104 are arranged in contact with each other. Driven by the developing roller gear 157 and the developer supply roller gear 158, the rollers rotate counterclockwise (directions C and D in the figure). The developer supply roller 104 is made of a sponge material and has the function of storing toner conveyed in the P1 direction by the agitating member 161 inside and supplying it to the developing roller 103. When the developer supply roller 104 comes into contact with the developing roller 103 and is crushed (region V), it expels the toner in the P2 direction. Therefore, in the developing chamber 164, toner circulates as indicated by arrows P1 and P2. The toner expelled in the P2 direction passes through the developing opening 151a and returns to the inside of the developer storage chamber.

[0082] (Agitation inside the development unit) Next, the stirring operation inside the developing unit 150 will be described with reference to FIG.

[0083] FIG. 14 is a time-series diagram illustrating the agitation operation of the agitation member 161. In this embodiment, as described above, the rotation radius R of the agitation member is set so that the first agitation sheet 161b and the second agitation sheet 161c penetrate into a portion of the inner wall of the container. Therefore, in the phase (first phase) shown in FIGS. 14(a) and 14(b), both the first agitation sheet 161b and the second agitation sheet 161c penetrate into the container, and the toner is divided into two regions (T1 and T2) inside the toner storage section 162 by the agitation member. In the phase (second phase) shown in FIG. 14(c), only one of the first agitation sheet 161b and the second agitation sheet 161c penetrates into the container.

[0084] Here, the developing chamber 164 is disposed below the toner storage unit 162 in the direction of gravity. Specifically, in this embodiment, when the toner storage unit 162 is installed in the image forming apparatus 1, the upper end of the developing opening 151a is disposed above the developer supply roller 103, and the rotation shaft 161a of the agitating member 161 is disposed above the developing opening 151a. At this time, the toner powder pressure F in the toner storage unit 162 acts on the developing opening 151a. In particular, if the toner storage unit 162 does not have the agitating member 161 or has only one agitating sheet, the toner powder pressure F becomes large, making it difficult to return a sufficient amount of toner from the developing chamber 164 to the toner storage unit 162, resulting in problems with circulation. However, in this embodiment, two agitating sheets are provided, and as shown in FIGS. 14(a) and 14(b), there is a phase in which two agitating sheets (161b and 161c) enter the container at the same time. At this time, the agitator 161 prevents the toner (T2) above the agitator 161 from falling, so that only the toner T1 remains above the developing opening 151a. This makes it possible to reduce the toner powder pressure F acting on the developing opening 151a. This allows a sufficient amount of toner in the developing chamber 164 to be returned to the toner storage portion 162, improving the toner circulation performance inside the developing unit 150.

[0085] Although the effect is reduced compared to the configuration of the above embodiment, it is still possible to achieve the effect even when the rotation radius R of the agitator is smaller than in the figure (the agitator sheet is shorter) and the agitator sheet does not penetrate into the container in the phase shown in FIG. 14(a). This is because, compared to when there is one short agitator sheet, when there are two short agitator sheets, a larger amount of toner accumulates on the agitator member 161 in the phase shown in FIG. 14(a), resulting in a relatively smaller volume of toner T2 and a reduced toner powder pressure F at the development opening 151a. Therefore, regardless of whether the agitator sheet penetrates into the container, providing two agitator sheets improves toner circulation. Note that the number of agitator sheets is not limited to two; if there are multiple agitator sheets, the powder pressure F can be reduced in the same way as when there is one agitator sheet. Therefore, providing multiple agitator sheets can improve toner circulation.

[0086] Furthermore, the lengths (short sides) of the two agitation sheets in the cross section of FIG. 14 are designed to penetrate into the developer opening 151a. This allows the agitation member 161 to temporarily remove the toner accumulated on the developer opening 151a as it penetrates into the developer opening 151a during rotation, facilitating the return of toner from the developer chamber 164 to the toner storage section 162. Additionally, in the phase shown in FIG. 14(c), where the agitation sheet 161b penetrates into the developer opening 151a, the agitation sheet 161c is provided on the opposite side of the agitation sheet 161b, thereby suppressing the flow of toner T1 from the right side to the toner T2 region from the left side in the figure. In this case, the powder pressure F acting on the developer opening 151a is relatively reduced compared to when there is only one agitation sheet (when the agitation sheet 161c is not present in the figure). Therefore, having two agitation sheets (161b and 161c) long enough to penetrate into the developer opening 151a is ultimately effective in improving toner circulation.

[0087] Furthermore, as shown in FIGS. 11 and 14(c), providing the opening-crossing rib 151b on the developer opening 151a of the first frame 151 eliminates the risk of the two agitating sheets coming into contact with the developer supply roller 104. Therefore, the rotation radius (R) of the agitating sheets can be secured to prevent the toner (T2) above the agitating member 161 from falling as shown in FIG. 14(a), while also allowing the distance L between the agitating member 161 and the developer opening 151a to be set small. By reducing the distance L, the agitating force of the two agitating sheets can be increased as they pass over the developer opening 151a, thereby reducing the toner powder pressure F. Therefore, providing the opening-crossing rib 151b on the developer opening 151a ultimately improves the toner circulation performance inside the development unit 150.

[0088] As described above, according to the proposed configuration, in a configuration in which the developing chamber 164 is located below the toner storage section 162, it is possible to reduce the toner powder pressure F acting on the developing opening 151a due to the toner's own weight, thereby improving the toner circulation performance inside the developing unit 150. When the toner circulation performance is improved, toner deterioration is less likely to progress even if the amount of toner stored increases, and the cartridge can have a longer lifespan. [Explanation of symbols]

[0089] 1. Electrophotographic image forming apparatus 2. Image forming device main body 3. Recording media 4 Feeding unit 4a Paper tray 4b Paper feed roller 5 Intermediate transfer unit 5a Transfer belt 5b Tension roller 5c Turn Roller 5d Primary transfer roller 5e Drive roller 6 Secondary transfer roller 7 Fixing device 8 Paper ejection device 9. Paper output tray 10 Front door 11 Laser scanner unit 12 Laser light 20 Cartridge Tray 20a Mounting part 30 Main body drum drive coupling 40 Main body side developing drive coupling 100 Process cartridge 101 Photosensitive drum 102 charging roller 103 Developing roller 104 Developer supply roller 120 drum unit 121 Drum frame 122 Drive side cartridge cover member 122a Drum support hole 122b Development unit support hole 123 Non-drive side cartridge cover member 123a Drum support hole 123b Development unit support hole 124 Drum flange 125 Coupling member 126 Drive side charging roller bearing unit 126a Drive side charging roller bearing 126b Pressure spring 127 Non-drive side charging roller bearing unit 127a Non-drive side charging roller bearing 127b Pressure spring 128 Exposure window 129 Drive side charging roller spacing member 130 Non-driving side charging roller spacing member 150 Development Unit 151 First developing frame 151a Development aperture 151b Opening cross rib 152 Second developing frame 153 Drive side bearing 154 Non-drive side bearing 155 Developing cover member 155a Cylindrical part 156 Developing blade 156a Support member 156b Elastic member 156c fixing screw 157 Developing roller gear 158 Developer supply roller gear 159 Development drive input gear 159a Development input coupling section 160 stirring gear 161 Stirring member 161a Agitator shaft 161b First stirring sheet 161c Second stirring sheet 161d Crimped boss 162 Toner storage unit 163 Sealing member 164 Developing Room 166 First guide rib 167 Second guide rib 168 Opening 170 Adhesive part 171 Blowout prevention sheet F Toner powder pressure L distance G Rotation direction of stirring member P1 direction P2 direction R: Radius of rotation of stirring member T1 Developer T2 Developer V area a Drum rotation axis b Swing axis

Claims

1. A cartridge that is mounted in an image forming apparatus and used to form an image, a storage chamber for storing toner; a rotatable developing roller that carries toner; a supply roller configured to be rotatable and supplying toner to the developing roller; a developing chamber communicating with the accommodation chamber through an opening and in which the developing roller and the supply roller are disposed; a stirring member provided inside the storage chamber for stirring the toner; The stirring member comprises: A rotating stirring shaft; a first stirring sheet member having one end fixed to the stirring shaft and the other end being a free end; a second stirring sheet member having one end fixed to the stirring shaft and the other end being a free end; Equipped with When viewed from the direction of the rotation axis of the stirring shaft, In the position where the image forming apparatus is mounted and used for forming an image, the developing chamber is provided below the storage chamber, At least a portion of the opening is located above the supply roller, The stirring shaft is located above the opening, With respect to an imaginary line passing through the rotation center of the stirring shaft, the second agitation sheet member is provided on the opposite side to the side where the first agitation sheet member is provided, and the lengths of the first agitation sheet member and the second agitation sheet member are each such that the other end of each can reach the opening when the agitation shaft rotates. A cartridge characterized by:

2. The first stirring sheet member and the second stirring sheet member are made of polycarbonate or polyphenylene sulfide and are sheets having a thickness of 50 μm or more and 200 μm or less.

2. The cartridge according to claim 1, wherein the cartridge comprises:

3. When the stirring member rotates around the rotation center, In a first phase, the first agitation sheet member and the second agitation sheet member are in contact with the inner wall of the storage chamber, In the second phase, the first agitation sheet member abuts against the inner wall of the storage chamber, and the second agitation sheet member does not abut against the inner wall of the storage chamber.

2. The cartridge according to claim 1.

4. The stirring member further includes a sheet-like sealing member, The sealing member has one end fixed to the first stirring sheet member and the other end configured to seal the opening in a new state, a width of the sealing member in the direction of the rotation axis of the agitator shaft is shorter than that of the first agitation sheet member; The thickness of the sealing member is thinner than that of the first stirring sheet member.

4. The cartridge according to claim 3.

5. the sealing member is fixed to the first agitation sheet member with double-sided tape, The first agitation sheet member and the second agitation sheet member are fixed to the agitation shaft by thermal caulking.

5. The cartridge according to claim 4.

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