Developing cartridge

Abstract

To provide a developing cartridge that can be reduced in size, while achieving a configuration that causes a center part of a blade in a longitudinal direction to project toward a developing roller compared with both ends of the blade in the longitudinal direction.SOLUTION: A developing cartridge 1 comprises: a developing roller 10 that is rotatable about a developing roller axis 10X extending in a first direction; a blade 30 that is in contact with the developing roller 10, the blade 30 extending in the first direction; a flat-shaped holder 40 that extends in the first direction, the holder 40 having a first surface 40A to which the blade 30 is attached and a second surface 40B located on the opposite side of the first surface 40A; and a flat-shaped plate 50 that extends in the first direction, the plate 50 having a first end face 50A in contact with the second surface 40B. A center 50C of the first end face 50A in the first direction projects toward the holder 40 compared with one end 50D and the other end 50E of the first end face 50A in the first direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a developer cartridge that includes a blade that contacts a developer roller. [Background technology]

[0002] Conventionally, a developer cartridge is known that includes a developer roller, a frame, and a layer thickness regulating blade (Patent Document 1). In this technology, the layer thickness regulating blade includes a blade having a rubber portion that contacts the developer roller and a blade metal plate that supports the rubber portion, a first support plate that supports the blade, and a second support plate that sandwiches the blade between the first support plate. The first support plate and the second support plate are formed by bending a metal plate into an L-shape. In addition, one end and the other end of the first support plate in the longitudinal direction are attached to the frame. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-55042 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, as the image forming apparatus in which the developer cartridge is mounted becomes smaller, there is a demand for a smaller developer cartridge. In addition, a configuration may be adopted in which the center of the blade in the longitudinal direction protrudes toward the developer roller beyond both ends of the blade in the longitudinal direction so that the blade comes into uniform contact with the developer roller along the longitudinal direction.

[0005] Therefore, an object of the present disclosure is to reduce the size of a developing cartridge while realizing a configuration in which the central portion of the blade in the longitudinal direction protrudes toward the developing roller further than both ends of the blade in the longitudinal direction. [Means for solving the problem]

[0006] The developing cartridge includes a developing roller rotatable about a developing roller axis extending in a first direction, a blade that contacts the developing roller, the blade extending in the first direction, a flat holder extending in the first direction, the holder having a first surface to which the blade is attached and a second surface located opposite the first surface, and a flat plate extending in the first direction, the plate having a first end surface that contacts the second surface. The center of the first end face in the first direction protrudes toward the holder further than one end and the other end of the first end face in the first direction.

[0007] According to this configuration, it is possible to realize a configuration in which the first end surface of the plate causes the central portion of the holder and the blade in the first direction to protrude toward the developing roller beyond both ends of the holder and the blade in the first direction. Furthermore, since the holder is flat, it is possible to reduce the size of the holder and the blade attached to the holder. This allows the developer cartridge to be reduced in size. In addition, since bending is not required, the holder can be easily manufactured.

[0008] The first end face can have a first convex portion protruding toward the holder, the first convex portion being located at the center of the first end face in the first direction, a second convex portion protruding toward the holder, the second convex portion being located between one end of the first end face and the first convex portion in the first direction, and a third convex portion protruding toward the holder, the third convex portion being located between the other end of the first end face and the first convex portion in the first direction, and the amount of protrusion of the first convex portion can be greater than the amount of protrusion of the second convex portion and the amount of protrusion of the third convex portion.

[0009] This makes it easy to manufacture a plate in which the central portions of the holder and the blade in the first direction protrude toward the developing roller further than both end portions of the holder and the blade in the first direction.

[0010] The first end face may have a fourth convex portion protruding toward the holder and located between the first convex portion and the second convex portion in the first direction, and a fifth convex portion protruding toward the holder and located between the first convex portion and the third convex portion in the first direction, and the amount of protrusion of the fourth convex portion is greater than the amount of protrusion of the second convex portion and less than the amount of protrusion of the first convex portion, and the amount of protrusion of the fifth convex portion is greater than the amount of protrusion of the third convex portion and less than the amount of protrusion of the first convex portion.

[0011] According to this, the stepped convex portion that protrudes toward the center in the first direction allows the shapes of the holder and the blade to be smoothly changed.

[0012] Moreover, the second surface is located on an opposite side to the first surface in a second direction intersecting the first direction, The center of the first end face in the first direction may be configured to protrude in the second direction toward the holder further than one end and the other end of the first end face in the first direction.

[0013] The developing cartridge can also be configured to include a developing frame to which the developing roller, blade, holder and plate are attached, the plate having a second end face located opposite the first end face in the second direction, and the developing frame having a protrusion that contacts the second end face.

[0014] According to this, when the first end surface of the plate receives a force from the second surface of the holder, the second end surface of the plate can be pressed against the protrusion, thereby making it possible to position the plate in the second direction.

[0015] The protrusion may include a first protrusion contacting one end of the second end surface in the first direction, and a second protrusion contacting the other end of the second end surface in the first direction.

[0016] This allows the plate to be positioned stably.

[0017] The developing frame may have a first frame to which the developing roller, the blade and the holder are attached, and a second frame to which the plate is attached, and the first frame may have a protrusion.

[0018] According to this, the plate can be directly positioned with respect to the first frame by the protrusion, so that the positional accuracy of the developing roller, the blade and the holder with respect to the plate can be improved.

[0019] The developing cartridge may further include a screw, the second frame may have a boss protruding in a third direction intersecting the first and second directions and having a screw hole into which the screw is inserted, and the plate may have a boss hole into which the boss is inserted, and the length of the boss in the third direction may be longer than the length of the plate in the third direction.

[0020] This prevents the plate from coming off the developing frame due to the screw. Also, because the length of the boss in the third direction is longer than the length of the plate in the third direction, the tightening force of the screw is not applied to the plate, so the plate can be reliably brought into contact with the protrusion. This allows the plate to be reliably positioned by the protrusion.

[0021] The holder may have a holder central portion located at the center of the holder in the first direction, a first holder end portion located at one end of the holder in the first direction, and a second holder end portion located at the other end of the holder in the first direction, and the length of the holder central portion in a third direction intersecting the first and second directions may be configured to be shorter than the length of the first holder end portion in the third direction and the length of the second holder end portion in the third direction.

[0022] Moreover, the length of the central portion of the holder in the third direction can be, for example, 5 mm or less.

[0023] The developer cartridge may also include a developer frame to which the developer roller, the blade, the holder and the plate are attached. Effect of the Invention

[0024] According to the present disclosure, it is possible to reduce the size of the developer cartridge while realizing a configuration in which the central portion of the blade in the first direction protrudes toward the developer roller further than both ends of the blade in the first direction. [Brief description of the drawings]

[0025] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] FIG. 2 is a cross-sectional view of the developing cartridge. [Figure 4] FIG. [Diagram 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 2 is a perspective view showing a plate and a developing frame. [Figure 8] FIG. [Figure 9] XX cross-sectional view of FIG. 8. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Next, an embodiment of the present disclosure will be described with reference to the drawings as appropriate. As shown in Fig. 1, the developer cartridge 1 is used in an electrophotographic image forming apparatus such as a laser printer, etc. The developer cartridge 1 is detachably mounted in the image forming apparatus.

[0027] 1 and 2, the developer cartridge 1 includes a developer roller 10, a supply roller 20, a blade unit BL, a plate 50, and a developer frame 60. The developer cartridge 1 further includes screws 71-73 for attaching the plate 50 to the developer frame 60, and fixing screws 81, 82 for attaching the blade unit BL to the developer frame 60. The screws 71-73 include a first screw 71, a second screw 72, and a third screw 73. The fixing screws 81, 82 include a first fixing screw 81 and a second fixing screw 82.

[0028] 2, the developing roller 10 is a roller having a surface that carries toner. The developing roller 10 is rotatable about a developing roller axis 10X that extends in a first direction. The developing roller 10 has a metallic developing roller shaft 11 that is rotatably supported by a developing frame 60, and a developing roller main body 12 that covers the developing roller shaft 11. The developing roller main body 12 is made of conductive rubber or the like.

[0029] Here, the first direction is the same as the longitudinal direction of the developing roller 10, the blade unit BL, and the plate 50. The second direction is a direction intersecting the first direction. Preferably, the second direction is a direction perpendicular to the first direction. The second direction is the same as the short side direction of the plate 50. The third direction is a direction intersecting the first direction and the second direction. Preferably, the third direction is a direction perpendicular to the first direction and the second direction. The third direction is the same as the short side direction of the blade unit BL.

[0030] 3, the supply roller 20 is a roller that supplies toner to the developing roller 10. The supply roller 20 is rotatable about a supply roller axis 20X that extends in a first direction. The supply roller 20 has a supply roller shaft 21 that is rotatably supported by the developing frame 60, and a supply roller body 22 that covers the supply roller shaft 21. The supply roller body 22 is made of a sponge or the like.

[0031] The blade unit BL is a member that regulates the toner supplied to the developing roller 10 into a thin layer of a constant thickness. The blade unit BL includes a blade 30 that contacts the developing roller 10 and a holder 40 that supports the blade 30.

[0032] As shown in Fig. 4, the blade 30 extends in a first direction. The blade 30 has a blade metal plate 31 and a rubber portion 32. The blade 30 also has a front side surface 30A and a rear side surface 30B located on the opposite side of the front side surface 30A. More specifically, the blade 30 has the front side surface 30A and a rear side surface 30B located on the opposite side of the front side surface 30A in the second direction. More specifically, the blade metal plate 31 has the front side surface 30A and the rear side surface 30B.

[0033] One end of the blade metal sheet 31 in the third direction is attached to the holder 40. The rubber portion 32 is attached to the other end of the blade metal sheet 31 in the third direction. More specifically, the rubber portion 32 is fixed to the other end of the blade metal sheet 31 in the third direction with an adhesive. The rubber portion 32 is a portion that comes into contact with the circumferential surface of the developing roller 10. The rubber portion 32 is attached to the front side surface 30A of the blade metal sheet 31. More specifically, the rubber portion 32 is fixed to the front side surface 30A of the blade metal sheet 31 with an adhesive.

[0034] The blade 30 has a first hole 34 and a second hole 35. More specifically, the blade sheet metal 31 has a first hole 34 and a second hole 35. The first hole 34 is a round hole, and the second hole 35 is a long hole that is long in the first direction. The second hole 35 is located away from the first hole 34 in the first direction. More specifically, the first hole 34 is located at one end of the blade sheet metal 31 in the first direction, and the second hole 35 is located at the other end of the blade sheet metal 31 in the first direction. In addition, the first hole 34 and the second hole 35 are located away from the rubber part 32 in the third direction. More specifically, the first hole 34 and the second hole 35 are located at one end of the blade sheet metal 31 in the third direction, and the rubber part 32 is located at the other end of the blade sheet metal 31 in the third direction.

[0035] The holder 40 extends in a first direction. The holder 40 is a flat member made of a metal plate. The thickness of the holder 40 in the second direction is greater than the thickness of the blade metal sheet 31 in the second direction. The holder 40 has a first surface 40A and a second surface 40B located on the opposite side of the first surface 40A. The first surface 40A is a surface to which the blade 30 is attached. The second surface 40B is located on the opposite side of the first surface 40A in the second direction.

[0036] The holder 40 has a holder central portion 41 , a first holder end portion 42 and a second holder end portion 43 .

[0037] The holder central portion 41 is located at the center of the holder 40 in the first direction. The holder central portion 41 has a first holder protrusion 44 and a second holder protrusion 45. The first holder protrusion 44 and the second holder protrusion 45 are substantially cylindrical protrusions and protrude from the first surface 40A toward the blade 30. The second holder protrusion 45 is located away from the first holder protrusion 44 in the first direction. Specifically, the first holder protrusion 44 is located at one end of the holder central portion 41 in the first direction, and the second holder protrusion 45 is located at the other end of the holder central portion 41 in the first direction.

[0038] With the rear side surface 30B of the blade 30 and the first surface 40A of the holder 40 in contact with each other, the first holder protrusion 44 fits into the first hole 34 of the blade 30, and the second holder protrusion 45 fits into the second hole 35 of the blade 30. Since the second hole 35 is an elongated hole that is long in the first direction, it is possible to absorb dimensional errors in the first direction of the first hole 34 and the second hole 35, and to absorb linear expansion in the first direction of the blade metal sheet 31 and the holder 40.

[0039] The first holder end 42 is located at one end of the holder 40 in the first direction. The first holder end 42 has a first fixing hole 46 through which a first fixing screw 81 (see FIG. 2) passes. The first fixing hole 46 is a round hole. The first fixing hole 46 is located at a position closer to one end of the holder 40 in the first direction than the first holder protrusion 44.

[0040] The second holder end 43 is located at the other end of the holder 40 in the first direction. The second holder end 43 has a second fixing hole 47 through which a second fixing screw 82 (see FIG. 2) passes. The second fixing hole 47 is an elongated hole that is long in the first direction. The second fixing hole 47 is located at a position closer to the other end of the holder 40 in the first direction than the second holder protrusion 45 in the first direction.

[0041] As shown in Fig. 5, the length H41 in the third direction of the holder central portion 41 is constant over the first direction. The length H41 in the third direction of the holder central portion 41 is shorter than the length H42 in the third direction of the first holder end portion 42 and the length H43 in the third direction of the second holder end portion 43. The length H41 in the third direction of the holder central portion 41 is, for example, 5 mm or less. The length H42 in the third direction of the first holder end portion 42 and the length H43 in the third direction of the second holder end portion 43 are approximately the same.

[0042] The blade unit BL is formed by fixing a blade 30 to a holder 40. More specifically, the blade 30 is fixed to the holder 40 by welding the back side 30B of the blade metal sheet 31 to the first surface 40A of the holder 40 in a contacting state. The back side 30B of the blade 30 is joined to the first surface 40A of the holder 40 by welding.

[0043] As shown in FIG. 6, the plate 50 extends in a first direction. The plate 50 is a flat member made of a metal plate. The shape of the plate 50 is different from the shape of the holder 40. The thickness of the plate 50 in the second direction is thicker than the thickness of the holder 40 in the second direction. The plate 50 has a plate center portion 51 which is the center of the plate 50 in the first direction, a first plate end portion 52 which is one end portion of the plate 50 in the first direction, and a second plate end portion 53 which is the other end portion of the plate 50 in the first direction.

[0044] The length in the second direction of the plate central portion 51 is longer than the length in the second direction of the first plate end portion 52 and the length in the second direction of the second plate end portion 53. The plate central portion 51 has three boss holes 54 and one plate recess 55.

[0045] 7, the boss holes 54 are through holes into which bosses 66 of the developing frame 60, which will be described later, are inserted. The boss holes 54 include a first boss hole 54A into which a first boss 66A, which will be described later, is inserted, a second boss hole 54B into which a second boss 66B, which will be described later, is inserted, and a third boss hole 54C into which a third boss 66C, which will be described later, is inserted.

[0046] The first boss hole 54A is an elongated hole that is long in the second direction. The length of the first boss hole 54A in the second direction, which is the longitudinal direction, is greater than the diameter of the first boss 66A. The length of the first boss hole 54A in the first direction, which is the transverse direction, is approximately the same as the diameter of the first boss 66A.

[0047] The second boss hole 54B is an elongated hole that is long in the second direction. The length of the second boss hole 54B in the second direction, which is the longitudinal direction, is greater than the diameter of the second boss 66B. The length of the second boss hole 54B in the first direction, which is the lateral direction, is greater than the diameter of the second boss 66B. The second boss hole 54B is located away from the first boss hole 54A in the first direction. Specifically, the first boss hole 54A is located at one end of the plate center portion 51 in the first direction, and the second boss hole 54B is located at the other end of the plate center portion 51 in the first direction.

[0048] The third boss hole 54C is an elongated hole that is long in the second direction. The length of the third boss hole 54C in the second direction, which is the longitudinal direction, is greater than the diameter of the third boss 66C. The length of the third boss hole 54C in the first direction, which is the lateral direction, is greater than the diameter of the third boss 66C. The third boss hole 54C is located away from the first boss hole 54A and the second boss hole 54B in the first direction. More specifically, the third boss hole 54C is located between the first boss hole 54A and the second boss hole 54B in the first direction. Specifically, the third boss hole 54C is located in the center of the plate center portion 51 in the first direction.

[0049] The plate recess 55 has a shape recessed toward a first end surface 50A of the plate 50, which will be described later. The plate recess 55 is located at one end of the plate central portion 51 in the first direction. More specifically, the plate recess 55 is located between the first boss hole 54A and the first plate end portion 52 in the first direction. The plate recess 55 is only located at one end of the plate central portion 51 in the first direction, and is not located at the other end of the plate central portion 51 in the first direction.

[0050] Returning to FIG. 6, the plate 50 has a first end surface 50A and a second end surface 50B located on the opposite side to the first end surface 50A. The first end surface 50A is a surface that comes into contact with the second surface 40B of the holder 40 (see FIG. 3). The first end surface 50A spans the plate center portion 51, the first plate end portion 52, and the second plate end portion 53 in the first direction.

[0051] A center 50C of the first end face 50A in the first direction protrudes further toward the holder 40 than one end 50D and the other end 50E of the first end face 50A in the first direction. In particular, the center 50C of the first end face 50A in the first direction protrudes further toward the holder 40 in the second direction than one end 50D and the other end 50E of the first end face 50A in the first direction.

[0052] Specifically, the first end surface 50A has a first convex portion 56A, a second convex portion 56B, a third convex portion 56C, a fourth convex portion 56D, and a fifth convex portion 56E. The first convex portion 56A, the second convex portion 56B, the third convex portion 56C, the fourth convex portion 56D, and the fifth convex portion 56E protrude toward the holder 40 in the second direction.

[0053] The first convex portion 56A is located at the center 50C of the first end surface 50A in the first direction. The second convex portion 56B is located between one end 50D of the first end surface 50A and the first convex portion 56A in the first direction. More specifically, the second convex portion 56B is located at one end of the plate center portion 51 in the first direction. The third convex portion 56C is located between the other end 50E of the first end surface 50A and the first convex portion 56A in the first direction. More specifically, the third convex portion 56C is located at the other end of the plate center portion 51 in the first direction. The fourth convex portion 56D is located between the first convex portion 56A and the second convex portion 56B in the first direction. The fifth convex portion 56E is located between the first convex portion 56A and the third convex portion 56C in the first direction.

[0054] The protruding amount of the first convex portion 56A is larger than the protruding amount of the second convex portion 56B and the protruding amount of the third convex portion 56C. The protruding amount here is the protruding amount from the plane PL connecting one end 50D and the other end 50E of the first end face 50A. The protruding amount of the second convex portion 56B and the protruding amount of the third convex portion 56C are approximately the same. The protruding amount of the fourth convex portion 56D is larger than the protruding amount of the second convex portion 56B and smaller than the protruding amount of the first convex portion 56A. The protruding amount of the fifth convex portion 56E is larger than the protruding amount of the third convex portion 56C and smaller than the protruding amount of the first convex portion 56A. The protruding amount of the fourth convex portion 56D and the protruding amount of the fifth convex portion 56E are approximately the same.

[0055] The protruding amount of the first convex portion 56A, the protruding amount of the second convex portion 56B, and the protruding amount of the fourth convex portion 56D increase in the order of the second convex portion 56B, the fourth convex portion 56D, and the first convex portion 56A from one end 50D of the first end face 50A toward the center 50C in the first direction. The protruding amount of the first convex portion 56A, the protruding amount of the third convex portion 56C, and the protruding amount of the fifth convex portion 56E increase in the order of the third convex portion 56C, the fifth convex portion 56E, and the first convex portion 56A from the other end 50E of the first end face 50A toward the center 50C in the first direction. The second convex portion 56B, the fourth convex portion 56D, the first convex portion 56A, the fifth convex portion 56E, and the third convex portion 56C are in a stepped shape that protrudes toward the center in the first direction.

[0056] The second end surface 50B is located on the opposite side to the first end surface 50A in the second direction. The second end surface 50B spans the plate center portion 51, the first plate end portion 52, and the second plate end portion 53 in the first direction. The second end surface 50B includes a second end surface center portion 51B located in the plate center portion 51, a second end surface one end portion 52B located in the first plate end portion 52, and a second end surface other end portion 53B located in the second plate end portion 53 in the first direction. The second end surface one end portion 52B and the second end surface other end portion 53B are located closer to the first end surface 50A than the second end surface center portion 51B in the second direction.

[0057] As shown in FIG. 2, the developing frame 60 is a member to which the developing roller 10, the supply roller 20, the blade 30, the holder 40, and the plate 50 are attached. The developing frame 60 rotatably supports the developing roller 10 and the supply roller 20. The developing frame 60 is made of resin or the like. The developing frame 60 has a storage chamber 60A (see FIG. 3) and an opening 60B. The storage chamber 60A stores toner. The opening 60B is an opening for supplying the toner in the storage chamber 60A to the developing roller 10.

[0058] 3, the developing frame 60 further includes a first frame 61 and a second frame 62. The first frame 61 has a box shape that is open on one side in the second direction and one side in the third direction. The second frame 62 covers the first frame 61 from one side in the third direction. The second frame 62 is fixed to the first frame 61 by welding, adhesion, or the like.

[0059] The first frame 61 is a portion to which the developing roller 10, the supply roller 20, the blade 30, and the holder 40 are attached. More specifically, the developing roller 10, the supply roller 20, and the blade unit BL are attached to the first frame 61. As shown in FIG. 7, the first frame 61 has a first supporting portion 63A and a second supporting portion 63B, a first fixing portion 64A and a second fixing portion 64B, and two protrusions 65.

[0060] The first support portion 63A and the second support portion 63B are portions that rotatably support the developing roller 10. More specifically, the first support portion 63A and the second support portion 63B rotatably support the developing roller shaft 11 via a bearing member. The second support portion 63B is located away from the first support portion 63A in the first direction. More specifically, the first support portion 63A is located on a first side wall 61A at one end side of the first frame 61 in the first direction, and the second support portion 63B is located on a second side wall 61B at the other end side of the first frame 61 in the first direction.

[0061] The first fixing portion 64A and the second fixing portion 64B are portions to which the blade unit BL is fixed. The first fixing portion 64A and the second fixing portion 64B are located between the first side wall 61A and the second side wall 61B in the first direction. The second fixing portion 64B is located away from the first fixing portion 64A in the first direction. Specifically, the first fixing portion 64A is located at one end of the first frame 61 in the first direction, and the second fixing portion 64B is located at the other end of the first frame 61 in the first direction. The first fixing portion 64A is located inside the first side wall 61A in the first direction, and the second fixing portion 64B is located inside the second side wall 61B in the first direction.

[0062] The two protrusions 65 are portions for positioning the plate 50 relative to the developing frame 60, more specifically, the first frame 61, and protrude in the third direction. The two protrusions 65 (see FIG. 9) contact the second end surface 50B of the plate 50 to position the plate 50 in the second direction. The two protrusions 65 include a first protrusion 65A and a second protrusion 65B.

[0063] 8, the first protrusion 65A contacts one end of the second end face 50B in the first direction. More specifically, the first protrusion 65A contacts one end 52B of the second end face. The first protrusion 65A is located at a position where the first plate end 52 of the plate 50 is sandwiched between the holder 40 and the first protrusion 65A in the second direction. In other words, the first plate end 52 is located between the holder 40 and the first protrusion 65A in the second direction.

[0064] The second protrusion 65B contacts the other end of the second end face 50B in the first direction. More specifically, the second protrusion 65B contacts the other end 53B of the second end face. The second protrusion 65B is located at a position where the second plate end 53 of the plate 50 is sandwiched between the holder 40 and the second protrusion 65B in the second direction. In other words, the second plate end 53 is located between the holder 40 and the second protrusion 65B in the second direction.

[0065] 7, the second frame 62 is a portion to which the plate 50 is attached. The plate 50 is attached to the second frame 62 so as not to come off the developing frame 60. The second frame 62 has three bosses 66 and one frame protrusion 67.

[0066] The three bosses 66 protrude in the third direction from the plate mounting surface 62A of the second frame 62. The three bosses 66 are cylindrical and have screw holes 66H into which the screws 71 to 73 are inserted. The three bosses 66 include a first boss 66A having a first screw hole 66HA, a second boss 66B having a second screw hole 66HB, and a third boss 66C having a third screw hole 66HC. The second boss 66B is located away from the first boss 66A in the first direction. Specifically, the first boss 66A is located at one end of the second frame 62 in the first direction, and the second boss 66B is located at the other end of the second frame 62 in the first direction. The third boss 66C is located away from the first boss 66A and the second boss 66B in the first direction. More specifically, the third boss 66C is located between the first boss 66A and the second boss 66B in the first direction. Specifically, the third boss 66C is located in the center of the second frame 62 in the first direction.

[0067] With the three bosses 66 inserted into the boss holes 54 of the plate 50, the screws 71 to 73 are inserted into the screw holes 66H of the three bosses 66 and fixed to the developing frame 60. In detail, the first screw 71 is inserted into the first screw hole 66HA of the first boss 66A and fixed to the second frame 62, the second screw 72 is inserted into the second screw hole 66HB of the second boss 66B and fixed to the second frame 62, and the third screw 73 is inserted into the third screw hole 66HC of the third boss 66C and fixed to the second frame 62.

[0068] The screw holes 66H may be holes into which the screws 71 to 73 are fixed. In this case, the screw holes 66H may be holes that already have thread grooves on their inner circumferential surfaces, or holes into which thread grooves are created when the screws 71 to 73 are fixed.

[0069] 3, the length H66 of the boss 66 in the third direction is longer than the length T50 of the plate 50 in the third direction. In other words, the amount of protrusion of the boss 66 from the plate mounting surface 62A is greater than the length H66 of the plate 50 in the third direction. Therefore, the tip of the boss 66 protrudes in the third direction from the plate 50 when the boss hole 54 of the plate 50 is inserted into the boss 66. The screws 71 to 73 do not contact the plate 50 when fixed to the developing frame 60. The plate 50 is positioned with a gap between it and the heads of the screws 71 to 73 in the third direction. The tightening force of the screws 71 to 73 is not applied to the plate 50.

[0070] Returning to FIG. 7, the frame protrusion 67 is a portion that fits into the plate recess 55 of the plate 50. The frame protrusion 67 is located at one end of the developing frame 60 in the first direction. More specifically, the frame protrusion 67 is located between the first protrusion 65A and the first boss 66A in the first direction. The frame protrusion 67 is only located at one end of the developing frame 60 in the first direction, and is not located at the other end of the developing frame 60 in the first direction.

[0071] Next, a brief description will be given of a manufacturing method of the developing cartridge 1. Specifically, a method of assembling the developing cartridge 1 will be described. As shown in FIG. 2, first, the supply roller 20 is attached to the developing frame 60.

[0072] Next, the plate 50 is attached to the developing frame 60. More specifically, first, the plate 50 is set on the plate attachment surface 62A of the developing frame 60. At this time, the boss holes 54 of the plate 50 are inserted into the bosses 66 of the developing frame 60, and the plate recesses 55 of the plate 50 are fitted into the frame protrusions 67 of the developing frame 60. Here, if the orientation of the plate 50 in the third direction is reversed, the plate recesses 55 and the frame protrusions 67 will not fit together, and the plate 50 cannot be set correctly on the plate attachment surface 62A. Fitting the plate recesses 55 and the frame protrusions 67 can prevent the plate 50 from being attached in reverse to the developing frame 60.

[0073] 7, the first screw 71 is fixed to the second frame 62 through the first screw hole 66HA of the first boss 66A, the second screw 72 is fixed to the second frame 62 through the second screw hole 66HB of the second boss 66B, and the third screw 73 is fixed to the second frame 62 through the third screw hole 66HC of the third boss 66C. This makes it possible to prevent the plate 50 from coming off the developing frame 60.

[0074] The length of the boss hole 54 in the second direction is larger than the diameter of the boss 66, and the plate 50 is positioned with a gap between it and the heads of the screws 71-73 in the third direction, so that the plate 50 is not fastened by the screws 71-73 (see FIG. 3). Therefore, the plate 50 is movable in the second direction while attached to the developing frame 60.

[0075] Furthermore, since the length of the first boss hole 54A in the first direction is approximately the same as the diameter of the boss 66, it is possible to position the plate 50 relative to the developing frame 60 in the first direction. Furthermore, since the lengths of the second boss hole 54B and the third boss hole 54C in the first direction are greater than the diameter of the boss 66, it is possible to absorb dimensional errors in the first direction between the boss holes 54 and to absorb linear expansion of the plate 50 and the developing frame 60 in the first direction.

[0076] Next, the blade unit BL is attached to the developing frame 60. Specifically, as shown in FIG. 2, the first fixing screw 81 is passed through the first fixing hole 46 of the holder 40 to fix it to the first fixing portion 64A of the developing frame 60, and the second fixing screw 82 is passed through the second fixing hole 47 of the holder 40 to fix it to the second fixing portion 64B of the developing frame 60.

[0077] 8, when the blade unit BL is attached to the developing frame 60, the second end surface 50B of the plate 50 comes into contact with the protrusion 65 of the developing frame 60. This makes it possible to position the plate 50 relative to the developing frame 60 in the second direction.

[0078] Further, in the blade unit BL, the second surface 40B of the holder 40 contacts the first end surface 50A of the plate 50. This allows the convex portions 56A-56E (see FIG. 6) of the first end surface 50A to protrude the center portion of the blade unit BL in the first direction toward the developing roller 10 further than both end portions of the blade unit BL in the first direction. In more detail, the center portions of the holder 40 and the blade 30 in the first direction can be protruded toward the developing roller 10 further than both end portions of the holder 40 and the blade 30 in the first direction.

[0079] Next, the developing roller 10 is attached to the developing frame 60. Specifically, as shown in Fig. 2, the developing roller shaft 11 of the developing roller 10 is positioned on the support portions 63A and 63B of the developing frame 60, and a cylindrical bearing member (not shown) is fitted to the developing roller shaft 11 and the support portions 63A and 63B from the outside in the first direction. This brings the developing roller 10 into contact with the blade 30. More specifically, the circumferential surface of the developing roller main body 12 of the developing roller 10 and the rubber portion 32 of the blade 30 come into contact with each other.

[0080] 9, the force applied from the developing roller 10 to the blade 30 is received by the developing frame 60 via the holder 40 and the plate 50. In detail, the force applied from the developing roller 10 to the rubber part 32 of the blade 30 is received by the protrusion 65 of the first frame 61 via the blade metal plate 31, the holder 40, and the plate 50.

[0081] According to the developing cartridge 1 of this embodiment, a configuration can be realized in which the first end surface 50A of the plate 50 causes the central portions of the holder 40 and the blade 30 in the first direction to protrude toward the developing roller 10 beyond both ends of the holder 40 and the blade 30 in the first direction. Furthermore, since the holder 40 is flat, more specifically, a flat plate shape that has not been subjected to bending, the holder 40 and the blade 30 attached to the holder 40 can be made small. This allows the developing cartridge 1 to be made small. Furthermore, since there is no need to perform bending, the holder 40 can be easily manufactured.

[0082] In addition, the first protrusion 56A of the first end face 50A and the like realizes a configuration in which the central parts of the holder 40 and the blade 30 in the first direction protrude toward the developing roller 10 further than both end parts of the holder 40 and the blade 30 in the first direction. This makes it easier to manufacture the plate 50 compared to, for example, a case in which the first end face is an arch-shaped curved surface.

[0083] Furthermore, the stepped projections 56A to 56E that protrude toward the center in the first direction allow the shapes of the holder 40 and the blade 30 to be smoothly changed.

[0084] In addition, since the developing frame 60 has the protrusion 65 that contacts the second end surface 50B of the plate 50, when the first end surface 50A of the plate 50 receives a force from the second surface 40B of the holder 40, the second end surface 50B of the plate 50 can be pressed against the protrusion 65. This makes it possible to position the plate 50 relative to the developing frame 60 in the second direction.

[0085] Furthermore, since the protrusion 65 includes the first protrusion 65A contacting the second end surface one end 52B and the second protrusion 65B contacting the second end surface other end 53B, the positioning of the plate 50 can be stably performed.

[0086] In addition, since the first frame 61 to which the developing roller 10, the blade 30 and the holder 40 are attached has the protrusions 65, the plate 50 can be directly positioned relative to the first frame 61 by the protrusions 65. This improves the positional accuracy of the developing roller 10, the blade 30 and the holder 40, and the plate 50.

[0087] Furthermore, the screws 71 to 73 can prevent the plate 50 from coming off the developing frame 60. Furthermore, because the length H66 of the boss 66 in the third direction is longer than the length T50 of the plate 50 in the third direction, the tightening force of the screws 71 to 73 is not applied to the plate 50. This allows the plate 50 to be reliably brought into contact with the protrusion 65, and the positioning of the plate 50 by the protrusion 65 can be reliably performed.

[0088] Although the embodiments have been described above, the present disclosure is not limited to the above-described embodiments, and can be modified as appropriate as exemplified below.

[0089] In the above embodiment, the first end surface 50A of the plate 50 has five protrusions 56A to 56E, but the present invention is not limited to this. For example, there may be a plurality of fourth protrusions. In this case, it is preferable that the protrusion amount of the plurality of fourth protrusions is greater as they are closer to the first protrusion in the first direction. The same applies to the fifth protrusion.

[0090] The first end surface of the plate may not have the fourth convex portion and the fifth convex portion. In this case, the second convex portion and the third convex portion may be connected to the first convex portion. The first end surface of the plate may have only the first convex portion. The first end surface of the plate may not have a convex portion, and may be an arched curved surface in which the center of the first end surface in the first direction protrudes toward the holder beyond one end of the first end surface in the first direction and the other end of the first end surface in the first direction.

[0091] In the above embodiment, the protrusion 65 of the developing frame 60 includes the first protrusion 65A and the second protrusion 65B, but the present invention is not limited to this. For example, the developing frame may have only one protrusion.

[0092] In the above embodiment, the blade 30 has the rubber portion 32, but the present invention is not limited to this. For example, the blade may have a configuration that does not include a rubber portion. In other words, the blade may have a blade metal that directly contacts the developing roller.

[0093] In the above-described embodiment, the blade 30 and the holder 40 are fixed to each other by welding, but this is not limiting. For example, the blade and the holder may be fixed to each other by adhesion or the like.

[0094] In the above embodiment, the developing cartridge 1 has the storage chamber 60A in which the toner is stored, but is not limited thereto. For example, the developing cartridge may be configured not to have a storage chamber. In this case, the developing cartridge may be configured to detachably mount a toner cartridge in which the toner is stored.

[0095] The elements described in the above embodiment and modified examples may be implemented in any combination. [Explanation of symbols]

[0096] 1 Developer cartridge 10 Developing roller 10X Developing roller shaft 30 Blades 40 Holder 40A Page 1 40B 2nd side 50 Plates 50A 1st end face 50C center 50D one end 50E other end

Claims

1. a developing roller rotatable about a developing roller axis extending in a first direction; a blade in contact with the developing roller, the blade extending in the first direction; a flat holder extending in the first direction, the holder having a first surface to which the blade is attached and a second surface located opposite to the first surface; a flat plate extending in the first direction and having a first end surface in contact with the second surface; a center of the first end surface in the first direction protrudes toward the holder further than one end and the other end of the first end surface in the first direction; The first end surface is a first protrusion protruding toward the holder and positioned at a center of the first end surface in the first direction; a second protrusion protruding toward the holder and positioned between one end of the first end surface and the first protrusion in the first direction; a third protrusion protruding toward the holder and positioned between the other end of the first end surface and the first protrusion in the first direction; having a protruding amount of the first convex portion is greater than a protruding amount of the second convex portion and a protruding amount of the third convex portion.

2. a developing roller rotatable about a developing roller axis extending in a first direction; a blade in contact with the developing roller, the blade extending in the first direction; a flat holder extending in the first direction, the holder having a first surface to which the blade is attached and a second surface located opposite to the first surface; a flat plate extending in the first direction and having a first end surface in contact with the second surface; a center of the first end surface in the first direction protrudes toward the holder further than one end and the other end of the first end surface in the first direction; the second surface is located on an opposite side to the first surface in a second direction intersecting the first direction, A developing cartridge characterized in that a center of the first end face in the first direction protrudes toward the holder in the second direction further than one end and the other end of the first end face in the first direction.

3. a developing roller rotatable about a developing roller axis extending in a first direction; a blade in contact with the developing roller, the blade extending in the first direction; a flat holder extending in the first direction, the holder having a first surface to which the blade is attached and a second surface located opposite to the first surface; a flat plate extending in the first direction and having a first end surface in contact with the second surface; a developing frame to which the developing roller, the blade, the holder and the plate are attached, a center of the first end surface in the first direction protrudes toward the holder further than one end and the other end of the first end surface in the first direction.

4. The first end surface is a first protrusion protruding toward the holder and positioned at a center of the first end surface in the first direction; a second protrusion protruding toward the holder and positioned between one end of the first end surface and the first protrusion in the first direction; a third protrusion protruding toward the holder and positioned between the other end of the first end surface and the first protrusion in the first direction; having 4. The developing cartridge according to claim 2, wherein a protruding amount of the first convex portion is greater than a protruding amount of the second convex portion and a protruding amount of the third convex portion.

5. The first end surface is a fourth convex portion protruding toward the holder and positioned between the first convex portion and the second convex portion in the first direction; a fifth convex portion protruding toward the holder and positioned between the first convex portion and the third convex portion in the first direction; having a protruding amount of the fourth convex portion is larger than a protruding amount of the second convex portion and is smaller than a protruding amount of the first convex portion; 5. The developing cartridge according to claim 1, wherein a protruding amount of the fifth convex portion is larger than a protruding amount of the third convex portion and smaller than a protruding amount of the first convex portion.

6. the second surface is located on an opposite side to the first surface in a second direction intersecting the first direction, A developing cartridge according to claim 1 or claim 3, characterized in that a center of the first end face in the first direction protrudes toward the holder in the second direction further than one end and the other end of the first end face in the first direction.

7. a developing frame to which the developing roller, the blade, the holder and the plate are attached, the plate has a second end surface located on the opposite side of the first end surface in the second direction, 7. The developing cartridge according to claim 6, wherein the developing frame has a projection that contacts the second end surface.

8. The protrusion is a first protrusion contacting one end of the second end surface in the first direction; a second protrusion contacting the other end of the second end surface in the first direction; The developing cartridge according to claim 7, further comprising:

9. The developing frame is a first frame to which the developing roller, the blade and the holder are attached; a second frame to which the plate is attached; having 9. The developing cartridge according to claim 7, wherein the first frame has the projection.

10. The developing cartridge further includes a screw. the second frame has a boss protruding in a third direction intersecting the first direction and the second direction, the boss having a screw hole into which the screw is inserted; the plate has a boss hole into which the boss is inserted, 10. The developing cartridge according to claim 9, wherein the length of the boss in the third direction is longer than the length of the plate in the third direction.

11. The holder includes: a holder center portion located at a center of the holder in the first direction; a first holder end portion located at one end portion of the holder in the first direction; a second holder end portion located at the other end portion of the holder in the first direction; having A developing cartridge as described in any one of claims 2 and 6 to 10, characterized in that the length of the central portion of the holder in a third direction intersecting the first direction and the second direction is shorter than the length of the first holder end portion in the third direction and the length of the second holder end portion in the third direction.

12. 12. The developing cartridge according to claim 11, wherein the length of the central portion of the holder in the third direction is 5 mm or less.

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