Developing cartridge

Abstract

To provide a technique for obtaining high positional accuracy of a plate with respect to a blade and a developing roller.SOLUTION: The developing cartridge 1 includes the casing 10 having the first frame 11 and the second frame 12, the developing roller 30 extending in the first direction, the blade 33 extending in the first direction and the third direction, and the plate 34 extending in the first direction and the second direction. The second frame 12 includes the boss 120 exposed to the outside of the first frame 11 through the opening 110 of the first frame 11. The blade 33 is attached to the second frame 12 and has one end portion in the third direction in contact with the developing roller 30. The plate 34 is disposed on the outer surface of the first frame 11, one end portion in the second direction of the plate 34 is in contact with the other end portion in the third direction of the blade 33, and the other end portion in the second direction of the plate 34 is in contact with the distal end portion 121 of the boss 120. With this, it is possible to ensure the positional accuracy in the second direction of the plate 34 with respect to the blade 33.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a developer cartridge. [Background technology]

[0002] 2. Description of the Related Art Conventionally, electrophotographic image forming apparatuses such as laser printers, LED printers, etc. A conventional image forming apparatus is described in, for example, Patent Document 1.

[0003] The image forming apparatus disclosed in Patent Document 1 includes a developer cartridge and a drum unit. The developer cartridge includes a developer roller. The drum unit includes a photosensitive drum. When the developer cartridge is attached to the drum unit, the developer roller comes into contact with the photosensitive drum.

[0004] Furthermore, the developer cartridge of Patent Document 1 has a blade that contacts the developer roller and a plate for adjusting the shape of the blade. The portion of the blade that contacts the developer roller is shaped so that the center in the axial direction (longitudinal direction) of the developer roller is convex. This prevents the pressing force at the center in the axial direction of the photosensitive drum from weakening when the developer roller contacts the photosensitive drum. The plate is provided to maintain the blade in the desired shape, so high positional accuracy relative to the blade is required. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-151903 Summary of the Invention [Problem to be solved by the invention]

[0006] In the developer cartridge of Patent Document 1, both ends of the blade and the plate in the longitudinal direction (the axial direction of the developing roller) are fixed to the frame. Therefore, in order to prevent the developing roller from warping in a direction perpendicular to the axial direction, the length and thickness of the plate in the lateral direction must be set to a certain value or more. In other words, in order to prevent deformation of the plate, there are restrictions on the shape of the plate. Therefore, in order to appropriately change the shape of the plate, it is necessary to ensure the positional accuracy of the plate relative to the blade by other methods.

[0007] An object of the present disclosure is to provide a technique for obtaining high positional accuracy of the plate relative to the blade and the developing roller. [Means for solving the problem]

[0008] The first disclosure relates to a housing having a toner chamber capable of containing toner, the housing including a first frame and a second frame that define the toner chamber; a developing roller rotatable about a development axis extending in a first direction, the developing roller being located at one end of the housing in a second direction that intersects with the first direction; a blade that extends in the first direction and widens in a third direction that intersects with the first and second directions, the blade having one end in the third direction that can come into contact with the developing roller; and a plate that extends in the first direction and also in the second direction, the one end in the second direction that contacts the developing roller at the other end of the blade in the third direction. and a plate that contacts a surface opposite the developing roller, wherein both ends in the first direction of the blade are attached to the second frame, the second frame has a boss that extends in the third direction from an inner surface that faces the first frame in the third direction and is exposed to the outside of the first frame through an opening in the first frame, the boss having a tip that is located on the opposite side of the plate from the developing roller in the second direction, the plate being arranged on the outer surface opposite the inner surface of the first frame, and the other end of the plate in the second direction contacts the tip of the boss.

[0009] The second disclosure is the developer cartridge of the first disclosure, characterized in that the boss has a stepped surface located between the tip portion and the inner peripheral surface of the second frame, and the stepped surface is welded to the edge of the opening in the inner peripheral surface of the first frame.

[0010] The third disclosure is the developing cartridge of the first disclosure, characterized in that it has a plurality of bosses arranged in the first direction, and each of the plurality of bosses contacts the other end of the plate in the second direction.

[0011] A fourth disclosure is the developing cartridge of the first disclosure, characterized in that the tip portion is disposed closer to the blade than the stepped surface in the second direction.

[0012] The fifth disclosure is a developing cartridge according to the fourth disclosure, characterized in that the first frame has a plate cover that covers the surface of the plate opposite the second frame in the third direction, and that extends from the other end side of the plate in the second direction toward one end side in the second direction.

[0013] The sixth disclosure is a developing cartridge according to the fourth disclosure, characterized in that the central portion of one end surface of the plate in the second direction protrudes toward one side in the second direction more than both ends of the plate in the first direction.

[0014] The seventh disclosure is a developing cartridge according to the third disclosure, characterized in that the plate consists of a plurality of divided plates spaced apart in the first direction, and each divided plate has the boss contacting the other end in the second direction.

[0015] The eighth disclosure is a developing cartridge according to the seventh disclosure, characterized in that the first frame has multiple pairs of plate covers covering both end portions of the dividing plate in the first direction, and each of the plate covers has a wall portion that protrudes in the third direction from the surface of the first frame on which the plate is placed, on the outside of the dividing plate in the first direction, and a cover portion that extends in the first direction from the tip of the wall portion and covers a portion of the surface of the dividing plate opposite the second frame in the third direction.

[0016] The ninth disclosure is a developing cartridge according to the seventh or eighth disclosure, wherein the plurality of dividing plates include a central plate arranged in the center of the first direction and a plurality of outer plates arranged on both sides of the central plate in the first direction, and one end face of the central plate in the second direction protrudes to one side in the second direction more than one end face of the outer plate in the second direction. [Effects of the Invention]

[0017] According to the first to ninth disclosures, the boss of the second frame to which the blade is fixed supports the other end in the second direction opposite to the contact point with the blade (one end in the second direction), thereby preventing the plate from bending in the second direction. This makes it possible to prevent deformation of the plate without limiting the shape of the plate. As a result, the other end in the third direction of the blade can be shaped as desired.

[0018] Furthermore, according to the second disclosure, the boss serves both to position the plate and to stabilize the shape of the first frame and the second frame.

[0019] Furthermore, according to the third disclosure, by supporting the plate at multiple points in the first direction, deformation of the plate can be further suppressed.

[0020] According to the fourth disclosure, the boss on the side closer to the blade (one side in the first direction) supports the plate. This makes it easier to narrow the plate width. As a result, the plate area can be reduced, thereby reducing the amount of charge.

[0021] Furthermore, according to the fifth disclosure, the plate cover prevents the plate from floating up and reduces the charging area, thereby suppressing charging.

[0022] According to the sixth disclosure, the blade shape is also convex in the center in the first direction, just like the plate, so that the part of the developing roller opposite the blade contact part that contacts the photosensitive drum can be firmly pressed against the photosensitive drum not only at both ends in the first direction but also at the center.

[0023] Furthermore, according to the seventh disclosure, the bosses can be used to position the plate in the second direction. This eliminates the need for positioning at both ends in the first direction as in the past, and the plate can be positioned partially. This allows the plate area to be reduced, thereby reducing the amount of charge.

[0024] According to the eighth disclosure, the plate covers can position the divided plates in the first direction and prevent the plates from floating up. Furthermore, the plate area can be reduced, thereby reducing the amount of static electricity.

[0025] According to the ninth disclosure, the blade shape is also convex in the center in the first direction, just like the plate, so that the part of the developing roller opposite the blade contact part that contacts the photosensitive drum can be firmly pressed against the photosensitive drum not only at both ends in the first direction but also at the center. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a schematic diagram of an image forming apparatus. [Figure 2] FIG. 2 is a partial cross-sectional view of a drum unit to which a developing cartridge is attached. [Figure 3] FIG. 2 is a perspective view of the developing cartridge according to the first embodiment. [Figure 4] FIG. 2 is a front view of the developing cartridge according to the first embodiment. [Figure 5] FIG. 2 is a cross-sectional view of the developing cartridge according to the first embodiment. [Figure 6] FIG. 2 is a perspective view of a second frame according to the first embodiment. [Figure 7] FIG. 10 is a perspective view of a developing cartridge according to a second embodiment. [Figure 8] FIG. 10 is a front view of a developing cartridge according to a second embodiment. [Figure 9] FIG. 10 is a cross-sectional view of a developing cartridge according to a second embodiment. [Figure 10] FIG. 10 is a perspective view of a second frame according to a second embodiment. [Figure 11] FIG. 10 is a plan view of a first frame to which divided plates according to a second embodiment are attached. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0028] In the following description, the direction in which the development shaft of the development roller 30 extends will be referred to as the "first direction." The width direction (short side direction) of the plate 34 of the development cartridge 1 will be referred to as the "second direction." The width direction (short side direction) of the blade 33 of the development cartridge 1 will be referred to as the "third direction."

[0029] The first direction and the second direction intersect with each other. For example, the first direction and the second direction are perpendicular to each other. The second direction and the third direction intersect with each other. For example, the second direction and the third direction are perpendicular to each other. The third direction and the first direction intersect with each other. For example, the third direction and the first direction are perpendicular to each other.

[0030] <1. Configuration of image forming device> FIG. 1 is a schematic diagram of an image forming apparatus 9. This image forming apparatus 9 is an electrophotographic printer. Specifically, the image forming apparatus 9 is a laser printer or an LED printer. The image forming apparatus 9 prints an image on the surface of printing paper using toner supplied from a developing cartridge 1.

[0031] 1, the image forming apparatus 9 includes a main body frame 90, a drum unit 2, and four developer cartridges 1. The developer cartridge 1 described here is the developer cartridge 1 of the first embodiment described below, but the same applies when the developer cartridge 1A of the second embodiment is used instead of the developer cartridge 1 of the first embodiment.

[0032] The four developer cartridges 1 can be attached to the drum unit 2. Furthermore, the drum unit 2 with the four developer cartridges 1 attached thereto can be attached to the main body frame 90.

[0033] The four developer cartridges 1 contain toner of different colors. For example, a developer cartridge 1 containing yellow toner, a developer cartridge 1 containing magenta toner, a developer cartridge 1 containing cyan toner, and a developer cartridge 1 containing black toner can be attached to the drum unit 2.

[0034] FIG. 2 is a cross-sectional view of an example of a drum unit 2 in which a developer cartridge 1 is attached. As shown in FIG. 2, when the developer cartridge 1 is attached to the drum unit 2, the developer roller 30 of the developer cartridge 1 comes into contact with the photosensitive drum 70 provided in the drum unit 2. The photosensitive drum 70 is charged by a charger 71, and then an electric latent image is formed on the surface of the photosensitive drum 70 by exposure. Then, the toner carried on the surface of the developer roller 30 adheres to the latent image portion of the photosensitive drum 70 and develops it. Thereafter, the toner on the photosensitive drum 70 is transferred to a printing substrate such as printing paper, thereby forming an image on the printing substrate.

[0035] 2. First Embodiment <2-1. Structure of the developing cartridge> Fig. 3 is a perspective view of the developer cartridge 1. Fig. 4 is a front view of the developer cartridge 1 when the developer cartridge 1 is viewed in a third direction. Fig. 5 is a cross-sectional view of the developer cartridge 1 taken along a cross section perpendicular to the first direction. As shown in Figs. 3 to 5, the developer cartridge 1 includes a housing 10, an agitator 20, a development roller 30, a supply roller 35, and a gear portion 40.

[0036] The housing 10 is a container capable of storing toner. The housing 10 has a first end surface 101 and a second end surface 102. The first end surface 101 is located at one end of the housing 10 in the first direction. The second end surface 102 is located at the other end of the housing 10 in the first direction. The first end surface 101 and the second end surface 102 are spaced apart from each other in the first direction.

[0037] The housing 10 has a first frame 11 and a second frame 12. The first frame 11 and the second frame 12 are aligned in the third direction. The first frame 11 and the second frame 12 are fixed to each other. As an example, the first frame 11 and the second frame 12 are welded to each other. As shown in FIG. 5 , the second frame 12 is cup-shaped. Specifically, the second frame 12 is recessed in a direction away from the first frame 11 in the third direction. The first frame 11 is generally plate-shaped. The first frame 11 covers the second frame 12.

[0038] A toner storage chamber 13 is provided inside the housing 10. The toner storage chamber 13 is a space surrounded by the first frame 11 and the second frame 12. That is, the toner storage chamber 13 is defined by the first frame 11 and the second frame 12. Toner is stored in the toner storage chamber 13. The housing 10 also has an end opening 14. The end opening 14 is located at one end of the housing 10 in the second direction. The external space of the housing 10 and the toner storage chamber 13 communicate with each other via the end opening 14.

[0039] The agitator 20 is a member that agitates the toner inside the housing 10. As shown in FIG. 5 , the agitator 20 has an agitator shaft 21 and an agitator blade 22. The agitator shaft 21 extends in a first direction inside the housing 10. The agitator shaft 21 is supported by the second frame 12 in a state in which it can rotate about the agitator axis extending in the first direction. The agitator blade 22 extends from the agitator shaft 21 toward the outside in the radial direction of the agitator shaft 21. The agitator 20 rotates about the agitator axis by a driving force supplied from the image forming device 9. This agitates the toner inside the housing 10.

[0040] The developing roller 30 is a roller that can rotate about a development axis that extends in the first direction. The developing roller 30 is located in an end opening 14 of the housing 10. That is, the developing roller 30 is located at one end of the housing 10 in the second direction. As shown in FIGS. 1 and 2, the drum unit 2 has a photosensitive drum 70. When the developing cartridge 1 is installed in the drum unit 2, the developing roller 30 comes into contact with the photosensitive drum 70.

[0041] As shown in FIG. 5, the developing roller 30 has a developing roller main body 31 and a developing roller shaft 32. The developing roller main body 31 is a cylindrical member extending in a first direction. The developing roller main body 31 is made of, for example, elastic rubber. The developing roller shaft 32 is a columnar member that penetrates the developing roller main body 31 and extends in the first direction. The developing roller main body 31 is fixed to the developing roller shaft 32. The developing roller shaft 32 is made of metal or conductive resin.

[0042] The developing roller 30 is supported by the second frame 12 in a state in which it can rotate about a development axis extending in the first direction. The developing roller 30 rotates about the development axis by a driving force supplied from the image forming device 9. The toner inside the housing 10 is carried on the outer surface of the developing roller 30.

[0043] As shown in FIG. 5 , the developer cartridge 1 also has a blade 33. The blade 33 is located in the end opening 14. The blade 33 extends in the first direction and widens in the third direction. One end of the blade 33 in the third direction is capable of contacting the developing roller 30. The other end of the blade 33 in the third direction is fixed to the housing 10. When a blade portion 333 (described later) of the blade 33 comes into contact with the toner carried on the outer peripheral surface of the developing roller 30, the blade portion 333 shapes the toner carried on the outer peripheral surface of the developing roller 30 to a predetermined thickness.

[0044] The supply roller 35 is a roller that can rotate about a supply axis that extends in the first direction. The supply roller 35 is located inside the housing 10. More specifically, the supply roller 35 is located between the developing roller 30 and the agitator 20 in the second direction.

[0045] As shown in FIG. 5, the supply roller 35 has a supply roller body 36 and a supply roller shaft 37. The supply roller body 36 is a cylindrical member extending in a first direction. The supply roller body 36 is made of, for example, elastic rubber. The outer circumferential surface of the supply roller body 36 contacts the outer circumferential surface of the developing roller body 31. The supply roller shaft 37 is a cylindrical member extending in the first direction through the supply roller body 36. The supply roller body 36 is fixed to the supply roller shaft 37. The supply roller shaft 37 is made of metal or conductive resin.

[0046] The supply roller 35 is supported by the second frame 12 in a state in which it can rotate about a supply shaft extending in the first direction. The supply roller 35 rotates about the supply shaft by a driving force supplied from the image forming device 9. The toner in the housing 10 is supplied to the outer circumferential surface of the developing roller 30 via the outer circumferential surface of the supply roller 35.

[0047] The gear unit 40 is located on the first end surface 101 of the housing 10. The gear unit 40 has a first cover 41, a coupling 42, and a plurality of gears. The first cover 41 is attached to the first end surface 101 of the housing 10. Specifically, the first cover 41 is fixed to the first end surface 101 of the housing 10 with screws.

[0048] The coupling 42 and the multiple gears are each rotatable about an axis extending in the first direction. At least some of the multiple gears are located between the first end surface 101 of the housing 10 and the first cover 41 in the first direction. In other words, at least some of the multiple gears are covered by the first cover 41.

[0049] The coupling 42 is exposed from the first cover 41. When the drum unit 2 with the developer cartridge 1 attached thereto is installed in the image forming device 9, the drive shaft of the image forming device 9 is connected to the coupling 42. Then, the rotation of the drive shaft is transmitted to the agitator 20, the developing roller 30, and the supply roller 35 via the coupling 42 and multiple gears.

[0050] <2-2. Specific configuration of the blade and its surroundings> The specific configuration of the blade 33 and its surrounding members will be described below.

[0051] The blade 33 has a plate-shaped portion 331, a holder portion 332, a blade portion 333, and a support portion 334. The plate-shaped portion 331 and the holder portion 332 may be separate parts, or may be molded as a single unit. The plate-shaped portion 331 may be welded to the holder portion 332, or may be attached by, for example, a screw.

[0052] The plate-shaped portion 331 is an elastic plate. The plate-shaped portion 331 extends with the first direction as its longitudinal direction and the third direction as its lateral direction. The plate-shaped portion 331 is, for example, a plate spring made of metal such as SUS. Hereinafter, the surface of the plate-shaped portion 331 facing the outside of the housing 10, i.e., the surface on the developing roller 30 side in the second direction, will be referred to as the first surface. Additionally, the surface of the plate-shaped portion 331 on the toner storage chamber 13 side inside the housing 10 will be referred to as the second surface.

[0053] The holder portion 332 is a plate that is thicker than the plate-shaped portion 331. The holder portion 332 is, for example, a metal plate. The holder portion 332 extends with the first direction as its longitudinal direction and the third direction as its lateral direction. The length of the holder portion 332 in the third direction is shorter than the length of the plate-shaped portion 331 in the third direction. The holder portion 332 is fixed to the second surface at the other end of the plate-shaped portion 331 in the third direction. Furthermore, both ends of the holder portion 332 in the first direction are fixed to the second frame 12 of the housing 10.

[0054] The blade portion 333 is a portion that extends in the first direction and comes into contact with the developing roller 30. The blade portion 333 is formed of, for example, resin. The blade portion 333 is fixed to the first surface at one end of the plate-shaped portion 331 in the third direction. The blade portion 333 extends in the first direction along the outer circumferential surface of the developing roller 30. The blade portion 333 comes into contact with the outer circumferential surface of the developing roller 30. More specifically, the blade portion 333 comes into contact with the toner carried on the outer circumferential surface of the developing roller 30. In this way, the blade portion 333 shapes the toner carried on the outer circumferential surface of the developing roller 30 to a predetermined thickness.

[0055] The support portion 334 is a plate-shaped portion extending in the first direction. The support portion 334 is formed of, for example, metal. The support portion 334 is fixed to the second surface at one end of the plate-shaped portion 331 in the third direction. In other words, the support portion 334 is fixed to the rear side of the portion of the plate-shaped portion 331 where the blade portion 333 is fixed. This improves the rigidity of the blade 33 near one end of the blade 33 in the third direction. As a result, the blade portion 333 can contact the developing roller 30 while maintaining a desired shape.

[0056] As shown in FIGS. 3 to 5, the developer cartridge 1 has a plate 34. The plate 34 is a plate extending in a first direction and a second direction. The plate 34 extends with the first direction as its longitudinal direction and the second direction as its short side direction (width direction). The plate 34 is made of, for example, metal.

[0057] The plate 34 is disposed along the outer surface 119 of the first frame 11, except for both ends in the first direction. Both ends of the plate 34 in the first direction are fixed to the second frame 12 of the housing 10. One end of the plate 34 in the second direction contacts the surface of the other end of the blade 33 in the third direction opposite to the developing roller 30. More specifically, the one end of the plate 34 in the second direction contacts the surface of the holder portion 332 of the blade 33 opposite to the plate-shaped portion 331.

[0058] The shape of one end face of the plate 34 in the second direction is such that the central portion in the first direction protrudes further in the second direction than both end portions in the first direction. That is, the central portion of one end face of the plate 34 in the second direction protrudes toward the blade 33. As a result, the entire blade 33 has a curved surface shape in which the center in the first direction protrudes toward one side in the second direction when viewed in the third direction. That is, the center in the first direction of the blade portion 333 that contacts the developing roller 30 also protrudes toward one side in the second direction.

[0059] As a result, the side of the developing roller 30 opposite to the point where the blade 33 contacts, i.e., the point of contact with the photosensitive drum 70, can be firmly pressed against the photosensitive drum 70 not only at both ends in the first direction but also in the center in the first direction.

[0060] Because of this role, the shape of the plate 34 (particularly one end surface in the second direction) requires high positional accuracy relative to the blade 33. Both end portions in the first direction of the blade 33 and the plate 34 are fixed to the second frame 12. That is, the blade 33 and the plate 34 are positioned with high accuracy relative to the second frame 12 at both end portions in the first direction. However, if there is no positioning means near the center in the first direction, the blade 33 and the plate 34 may bend near the center in the first direction, which may reduce the positional accuracy. Therefore, in order to improve the positional accuracy of the plate 34 relative to the blade 33, it is preferable to provide a positioning means for the plate 34 with respect to the second frame 12 at a location other than both end portions in the first direction.

[0061] FIG. 6 is a perspective view of the second frame 12. As shown in FIGS. 3 to 6, the second frame 12 of the housing 10 has a plurality of bosses 120. The plurality of bosses 120 are arranged at intervals in the first direction. In this embodiment, the second frame 12 has five bosses 120. The bosses 120 extend in the third direction from an inner circumferential surface 129 of the second frame 12 that faces the first frame 11. In other words, one end of the boss 120 in the third direction is connected to the inner circumferential surface of the second frame 12.

[0062] The first frame 11 of the housing 10 also has a plurality of openings 110. In this embodiment, the number of openings 110 is five, which is the same as the number of bosses 120. The bosses 120 are exposed to the outside of the first frame 11 through the openings 110. That is, the other end of each boss 120 in the third direction is exposed to the outside of the first frame 11. Hereinafter, the portion of each boss 120 that is exposed to the outside of the first frame 11 will be referred to as a tip portion 121.

[0063] The boss 120 has a stepped surface 122 between the tip end 121 and an inner circumferential surface 129 of the second frame 12. In this embodiment, the cross section of the boss 120 perpendicular to the third direction between one end of the boss 120 in the third direction and the stepped surface 122 is substantially annular. The stepped surface 122 is welded to the edge of the opening 110 in the inner circumferential surface of the first frame 11. This makes it possible to maintain a predetermined distance between the first frame 11 and the second frame 12 in the third direction.

[0064] The tip 121 of the boss 120 contacts the other end of the plate 34 in the second direction. The portion of the tip 121 that contacts the plate 34 has a surface perpendicular to the second direction so as to contact the other end face of the plate 34 in the second direction. As a result, each of the multiple tip portions 121 positions the other end of the plate 34 in the second direction in the second direction. That is, the other end of the plate 34 in the second direction, which is opposite the one end of the second direction that is in contact with the blade 33, is positioned at multiple locations in the first direction with respect to the second frame 12. As a result, bending of the plate 34 in the second direction can be suppressed. Therefore, deformation of the plate 34 can be suppressed without limiting the shape of the plate 34.

[0065] In this embodiment, the tip 121 of the boss 120 is disposed closer to the blade 33 in the second direction than the step surface 122. This allows the width of the plate 34 in the second direction to be reduced.

[0066] Conventionally, the plate 34 has a certain width to prevent deformation of the plate 34. However, as shown in FIG. 2, when the image forming apparatus 9 is in use, the plate 34 is positioned relatively close to the charger 71. As a result, the plate 34 may become charged by static electricity generated by the charger 71, and a large amount of static electricity may accumulate on the plate 34 that cannot be dissipated. To address this problem, it is conceivable to reduce the amount of static electricity accumulated on the plate 34 by reducing the exposed area of ​​the plate 34. However, when the plate 34 is positioned only by the fixing points at both ends in the first direction, as in the conventional case, reducing the width of the plate 34 causes the plate 34 to bend in the second direction, making it difficult to maintain the desired shape of the blade 33.

[0067] In this developing cartridge 1, the plate 34 is positioned in the second direction by the boss 120 of the second frame 12, so that the plate 34 does not bend even if the width of the plate 34 in the second direction is reduced. As a result, the amount of charge on the plate 34 can be reduced while the blade 33 can be appropriately supported.

[0068] As shown in FIGS. 3 to 5, the first frame 11 has a plurality of plate covers 111. The plurality of plate covers 111 are arranged at intervals in the first direction. The plate covers 111 extend from the other end of the plate 34 in the second direction toward one end in the second direction. Each of the plate covers 111 covers the surface of the plate 34 opposite the second frame 12 in the third direction. This prevents the plate 34 from floating up. Furthermore, the exposed area of ​​the plate 34 is reduced by being covered by the plate covers 111. This further suppresses charging of the plate 34.

[0069] <3. Regarding the Second Embodiment> The following describes the configuration of the developer cartridge 1A according to the second embodiment, which differs from that of the first embodiment, with reference to Figures 7 to 9. Figure 7 is a perspective view of the developer cartridge 1A. Figure 8 is a front view of the developer cartridge 1A. Figure 9 is a cross-sectional view of the developer cartridge 1A. Figure 10 is a perspective view of the second frame 12A of the developer cartridge 1A.

[0070] The developing cartridge 1A of this embodiment differs in the shape of the plate 34A and the periphery of the plate 34A of the housing 10A. Regarding the housing 10A, the shape of the plate cover 111A of the first frame 11A and the shape of the boss 120A of the second frame 12A are particularly different. The rest of the configuration is the same as in the first embodiment, and therefore description thereof will be omitted.

[0071] 7 and 8, the plate 34A of this embodiment is made up of multiple divided plates 340A spaced apart in the first direction. That is, the plate 34A is partially arranged in the first direction. While the developer cartridge 1A has three divided plates 340A, the number of divided plates 340A may be two, four, or more.

[0072] The divided plates 340A are plates extending in the first direction and the second direction. The divided plates 340A are made of, for example, metal. The divided plates 340A are arranged along the outer surface 119A of the first frame 11. One end of the divided plate 340A in the second direction contacts the surface of the other end of the blade 33 in the third direction, opposite to the developing roller 30. More specifically, one end of the divided plate 340A in the second direction contacts the surface of the holder portion 332 of the blade 33, opposite to the plate-shaped portion 331.

[0073] The other end of the divided plate 340A in the second direction comes into contact with the boss 120A, thereby positioning the divided plate 340A in the second direction.

[0074] In this embodiment, the three divided plates 340A consist of one central plate 341A and two outer plates 342A. The central plate 341A is located in the center of the three divided plates 340A in the first direction. The two outer plates 342A are located on both sides of the central plate 341A in the first direction.

[0075] One end face of the center plate 341A in the second direction protrudes further toward one side in the second direction than one end face of the outer plate 342A in the second direction. That is, the surface of the center plate 341A that contacts the blade 33 protrudes further toward the blade 33 than the surface of the outer plate 342A that contacts the blade 33. As a result, similar to the first embodiment, the blade 33 has a curved surface shape in which the center in the first direction protrudes toward one side in the second direction when viewed in the third direction. That is, the center in the first direction of the blade portion 333 that contacts the developing roller 30 also protrudes toward one side in the second direction.

[0076] As a result, the side of the developing roller 30 opposite to the point where the blade 33 contacts, i.e., the point of contact with the photosensitive drum 70, can be firmly pressed against the photosensitive drum 70 not only at both ends in the first direction but also in the center in the first direction.

[0077] Because of this role, each divided plate 340A (particularly one end surface in the second direction) is required to have high positional accuracy in the second direction relative to the blade 33. This plate 34A is divided in the first direction, and therefore both ends in the first direction are fixed to the second frame 12A, as in the first embodiment. Therefore, in order to ensure the positional accuracy of the plate 34A relative to the blade 33, it is necessary to provide a positioning means for the plate 34A relative to the second frame 12A.

[0078] FIG. 10 is a perspective view of the second frame 12A. As shown in FIGS. 7 to 10, the second frame 12A of the housing 10A has a plurality of bosses 120A. The plurality of bosses 120A are arranged at intervals in the first direction. In this embodiment, the second frame 12A has three bosses 120A. The bosses 120A extend in the third direction from an inner circumferential surface 129A of the second frame 12A that faces the first frame 11A. In other words, one end of the boss 120A in the third direction is connected to the inner circumferential surface of the second frame 12A.

[0079] The first frame 11A of the housing 10A has a plurality of openings 110A. In this embodiment, the number of openings 110A is three, which is the same as the number of bosses 120A. The bosses 120A are exposed to the outside of the first frame 11A through the openings 110A. That is, the other end of each boss 120A in the third direction is exposed to the outside of the first frame 11A. Hereinafter, the portion of each boss 120A that is exposed to the outside of the first frame 11A will be referred to as a tip portion 121A.

[0080] The boss 120A has a stepped surface 122A between the tip end 121A and the inner circumferential surface 129A of the second frame 12A. In this embodiment, the cross section of the boss 120A perpendicular to the third direction from one end of the boss 120A in the third direction to the stepped surface 122A is substantially annular. In this embodiment, the stepped surface 122A of the boss 120A is positioned closer to the blade 33 than the tip end 121A in the second direction. The stepped surface 122A is welded to the edge of the opening 110A in the inner circumferential surface of the first frame 11A. This allows the distance in the third direction between the first frame 11A and the second frame 12A to be maintained at a predetermined length.

[0081] The tip 121A of the boss 120A contacts the other end of the divided plate 340A in the second direction. The portion of the tip 121A that contacts the divided plate 340A has a surface perpendicular to the second direction so as to contact the other end face of the divided plate 340A in the second direction. As a result, each of the multiple tip 121A positions the other end of the divided plate 340A in the second direction. That is, the other end of the divided plate 340A in the second direction, opposite the one end of the second direction that is in contact with the blade, is positioned at multiple points in the first direction relative to the second frame 12A.

[0082] In this embodiment, the number of bosses 120A is the same as the number of divided plates 340A. The tip end 121 of one boss 120A contacts one divided plate 340A. This positions the other end in the second direction of all divided plates 340A. Note that the number of bosses 120A for one divided plate 340A may be two or more.

[0083] Conventionally, the length of the plate in the first direction is approximately the same as the length of the blade 33 in the first direction. In contrast, in the plate 34A of this embodiment, the total length of all divided plates 340A in the first direction is less than half the length of the blade 33 in the first direction. Meanwhile, as shown in FIG. 2, when the image forming apparatus 9 is in use, the plate 34 is disposed relatively close to the charger 71. As a result, the plate 34 may become charged by static electricity generated by the charger 71, and a large amount of static electricity may accumulate that cannot be dissipated. To address this problem, the plate 34A of this embodiment has a smaller exposed area than conventional plates.

[0084] In this developer cartridge 1A, the bosses 120A of the second frame 12A position each divided plate 340A in the second direction. This eliminates the need to position the plate 34A at both ends in the first direction. Therefore, even if the total length of the plate 34A in the first direction is reduced, the plate 34A does not bend in the second direction. As a result, the amount of charge on the plate 34A can be reduced while properly supporting the blade 33.

[0085] 7 and 8, the first frame 11A has multiple pairs of plate covers 111A. Both ends of the divided plate 340A in the first direction are covered by a pair of plate covers 111A. Each pair of plate covers 111A includes a first plate cover 112A that covers one end of the divided plate 340A in the first direction, and a second plate cover 113A that covers the other end of the divided plate 340A in the first direction.

[0086] 11 is a plan view of the first frame 11A with three divided plates 111A attached, viewed from the second direction. As shown in FIG. 11, each plate cover 111A has a wall portion 51A and a cover portion 52A. The wall portion 51A protrudes in the third direction from the outer surface 119A on which the plate 34A of the first frame 11A is placed, on the outer side of the divided plate 340A in the first direction. The cover portion 52A extends in the first direction from the tip of the wall portion 51A and covers a portion of the surface of the divided plate 340A opposite the second frame 12A in the third direction.

[0087] This prevents the plate 34 from floating up. Furthermore, the exposed area of ​​the plate 34A is reduced by being covered by the cover portion 52A of the plate cover 111A, which further suppresses charging.

[0088] <4. Modifications> Although two embodiments have been described above, the present disclosure is not limited to the above embodiments.

[0089] In the above embodiment, the plate covers 111, 111A are provided on the first frames 11, 11A, but the present invention is not limited to this.

[0090] In the above embodiment, the number of developer cartridges 1 that can be attached to the drum unit 2 is four. However, the number of developer cartridges 1 that can be attached to the drum unit 2 may be one to three, or may be five or more.

[0091] In addition, the detailed shape and structure of the developing cartridge may be appropriately changed without departing from the spirit of the present invention. Furthermore, the elements appearing in the above-described embodiment and modified examples may be appropriately selected without departing from the spirit of the present invention. [Explanation of symbols]

[0092] 1,1A Developer Cartridge 9. Image forming device 10,10A housing 11,11A 1st frame 12,12A 2nd frame 13 Toner Storage Chamber 30 Developing roller 33 Blade 34,34A Plate 51A Wall section 52A Cover 110,110A aperture 111,111A Plate cover 120,120A boss 121,121A Tip 122,122A Step surface 331 Plate-shaped part 332 Holder part 333 Blade section 334 Support part 340A Divided Plate 341A Center Plate 342A Outer Plate

Claims

1. a housing having a toner chamber capable of containing toner, the housing including a first frame and a second frame defining the toner chamber; a developing roller rotatable about a developing shaft extending in a first direction, the developing roller being located at one end of the housing in a second direction intersecting the first direction; a blade extending in the first direction and widening in a third direction intersecting the first direction and the second direction, the blade having one end in the third direction capable of contacting the developing roller; a plate extending in the first direction and the second direction, wherein one end of the plate in the second direction contacts a surface of the blade at the other end of the blade in the third direction on the opposite side from the developing roller; and the blade is attached to the second frame at both ends in the first direction; The second frame is a boss extending in the third direction from an inner peripheral surface facing the first frame in the third direction and exposed to an outside of the first frame through an opening in the first frame, the boss having a tip portion positioned on the opposite side of the plate from the developing roller in the second direction; and A developing cartridge characterized in that the plate is arranged on an outer surface opposite the inner surface of the first frame, and the other end of the plate in the second direction contacts the tip portion of the boss.

2. 2. The developing cartridge according to claim 1, The boss is A developing cartridge characterized in that it has a stepped surface located between the tip portion and the inner surface of the second frame, the stepped surface being welded to the edge of the opening in the inner surface of the first frame.

3. 2. The developing cartridge according to claim 1, a plurality of the bosses arranged in the first direction; a plurality of bosses each contacting the other end of the plate in the second direction;

4. 3. The developing cartridge according to claim 2, a developing cartridge, wherein the tip portion is disposed closer to the blade than the stepped surface in the second direction;

5. 5. The developing cartridge according to claim 4, The first frame is a plate cover that covers a surface of the plate opposite to the second frame in the third direction, the plate cover extending from the other end side of the plate in the second direction toward the one end side in the second direction; A developing cartridge comprising:

6. 5. The developing cartridge according to claim 4, A developing cartridge, characterized in that a central portion in the first direction of one end surface of the plate in the second direction protrudes toward one side in the second direction beyond both end portions of the plate in the first direction.

7. 4. The developing cartridge according to claim 3, The plate is a plurality of divided plates spaced apart in the first direction; It consists of The developing cartridge is characterized in that the boss contacts the other end of each of the divided plates in the second direction.

8. 8. The developing cartridge according to claim 7, The first frame is a plurality of pairs of plate covers covering both end portions of the dividing plate in the first direction, and Each of the plate covers comprises: a wall portion that protrudes in the third direction from a surface of the first frame on which the plate is placed, on an outer side of the divided plate in the first direction; a cover portion extending in the first direction from a tip of the wall portion and covering a part of a surface of the divided plate opposite to the second frame in the third direction; A developing cartridge comprising:

9. 9. The developing cartridge according to claim 7, The plurality of dividing plates include: a center plate disposed at the center in the first direction; a plurality of outer plates disposed on both sides of the central plate in the first direction; Including, a developing cartridge, wherein one end surface of the center plate in the second direction protrudes further to one side in the second direction than one end surface of each of the outer plates in the second direction;

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