Developing cartridge

Abstract

This invention provides a new structure for image forming apparatus that further develops conventional technology. [Solution] The developing cartridge 1 comprises a housing 10, a developing roller 20, a separating member 45, a memory 41, and a holder 42. The housing 10 has a toner storage chamber and a toner filling port 162 for filling the toner storage chamber with toner. The toner filling port 162 is located at one end of the housing 10 in a first direction. The holder 42 is located at the other end of the housing 10 in a first direction. The holder 42 holds the electrical contact surface of the memory 41 movably relative to the housing 10. The holder 42 overlaps with the toner filling port 162 in a first direction.

Description

Technical Field

[0001] This disclosure relates to a developing cartridge.

Background Art

[0002] Conventionally, an electrophotographic image forming apparatus is known. The image forming apparatus includes a developing cartridge having a developing roller and a drum unit having a photosensitive drum. The developing cartridge is attached to the drum unit. Further, the drum unit to which the developing cartridge is attached is attached to the main body frame of the image forming apparatus. A conventional image forming apparatus including the developing cartridge and the drum unit is described in, for example, Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, there is still room for further improvement in the image forming apparatus of Patent Document 1. The object of this disclosure is to provide a new structure that further develops the prior art in an image forming apparatus.

Means for Solving the Problems

[0005] The developer cartridge of this disclosure comprises a housing having a toner storage chamber for storing toner and a toner filling port located at one end in a first direction for filling the toner storage chamber with toner; a developer roller rotatable about an axis extending in the first direction and located at one end of the housing in a second direction intersecting the first direction; a cap attached to one end of the housing in the first direction and covering the toner filling port; a separating member movable in the first direction relative to the housing and having a separating shaft extending in the first direction and a first inclined surface located at one end of the separating member in the first direction, the first inclined surface moving away from the developer roller in the second direction as it approaches the other end of the separating member in the first direction; a memory having an electrical contact surface; and a holder located at the other end of the housing in the first direction for movably holding the electrical contact surface relative to the housing, wherein the holder overlaps with the toner filling port in the first direction. [Effects of the Invention]

[0006] According to this disclosure, it is possible to provide a new image forming apparatus that further develops the prior art. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram of an image forming apparatus. [Figure 2] This is a perspective view of a developing cartridge. [Figure 3] This is a perspective view of a developing cartridge. [Figure 4] This is a perspective view of a developing cartridge. [Figure 5] This diagram shows the developing cartridge viewed from the first toner frame side towards the third direction. [Figure 6] This diagram shows the developing cartridge viewed from the second toner frame side towards the third direction. [Figure 7] This is a diagram showing the developing cartridge viewed from one side in the first direction. [Figure 8] It is a view of the developing cartridge seen from the other side in the first direction. [Figure 9] It is a cross-sectional view of the developing cartridge at the position of the A-A line in FIG. 5. [Figure 10] It is an exploded perspective view of the housing and the agitator. [Figure 11] It is an exploded perspective view of the housing, the first bearing, and the second bearing. [Figure 12] It is an exploded perspective view of the housing and the developing roller. [Figure 13] It is an exploded perspective view of the housing and the blade unit. [Figure 14] It is an exploded perspective view of the housing and the supply roller. [Figure 15] It is a partial cross-sectional view of the developing cartridge near the other end of the supply roller shaft in the first direction. [Figure 16] It is an exploded perspective view of the gear unit. [Figure 17] It is a view of the developing cartridge with the gear cover removed, seen from the gear cover side in the first direction. [Figure 18] It is a view of the vicinity of the first end face of the developing cartridge with the gear cover removed, seen from the second toner frame side in the third direction. [Figure 19] It is an exploded perspective view of the memory assembly. [Figure 20] It is a perspective view of the memory and the holder. [Figure 21] It is an exploded perspective view of the memory and the holder. [Figure 22] It is a perspective view of the developing cartridge with the gear unit removed. [Figure 23] It is a perspective view of the developing cartridge with the gear unit and the separation member removed. [Figure 24] It is a perspective view of the drum unit. [Figure 25] It is a perspective view of the drum unit with four developing cartridges mounted. [Figure 26]A cross-sectional view of a drum unit with a developing cartridge mounted thereon, including a separation member. [Figure 27] A cross-sectional view of a drum unit with a developing cartridge mounted thereon, including a separation member.

Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0009] In the following, the direction in which the rotation axis of the developing roller 20 extends is referred to as the "first direction". Also, the direction in which one end of the housing 10 of the developing cartridge 1 where the developing roller 20 is located and the other end of the housing 10 are aligned is referred to as the "second direction". Further, the direction intersecting the electrical contact surface 411 of the memory 41 is referred to as the "third direction".

[0010] The first direction and the second direction intersect each other. For example, the first direction and the second direction are perpendicular to each other. The second direction and the third direction intersect each other. For example, the second direction and the third direction are perpendicular to each other. The third direction and the first direction intersect each other. For example, the third direction and the first direction are perpendicular to each other.

[0011] <1. Configuration of the Image Forming Apparatus> FIG. 1 is a schematic diagram of an image forming apparatus 100. This image forming apparatus 100 is an electrophotographic printer. Specifically, the image forming apparatus 100 is a laser printer or an LED printer. As shown in FIG. 1, the image forming apparatus 100 includes a main body frame 101, a drum unit 2, and four developing cartridges 1.

[0012] The four developing cartridges 1 can be mounted on the drum unit 2. Also, the drum unit 2 with the four developing cartridges 1 mounted thereon can be mounted on the main body frame 101. The drum unit 2 is mounted on the main body frame 101 by moving in the third direction with respect to the main body frame 101.

[0013] The developing cartridge 1 contains toner. The developing cartridge 1 also has a developing roller 20. The drum unit 2 has four photoreceptor drums 50. When the developing cartridge 1 is installed in the drum unit 2, the developing roller 20 and the photoreceptor drums 50 come into contact.

[0014] The toner in the developing cartridge 1 is supplied to the photoreceptor drum 50 via the developing roller 20. The image forming apparatus 100 prints an image on the printing paper by transferring the toner from the photoreceptor drum 50 to the printing paper.

[0015] The four developing cartridges 1 each contain toner of a different color. For example, the four developing cartridges 1 may be a developing cartridge 1 containing yellow toner, a developing cartridge 1 containing magenta toner, a developing cartridge 1 containing cyan toner, and a developing cartridge 1 containing black toner. The image forming apparatus 100 prints an image on the surface of the printing paper using the toner supplied from the developing cartridges 1.

[0016] <2. Developer Cartridge Configuration> Figures 2, 3, and 4 are perspective views of the developer cartridge 1. Figure 5 is a view of the developer cartridge 1 from the first toner frame 15 side in the third direction. Figure 6 is a view of the developer cartridge 1 from the second toner frame 16 side in the third direction. Figure 7 is a view of the developer cartridge 1 from one side in the first direction. Figure 8 is a view of the developer cartridge 1 from the other side in the first direction. Figure 9 is a cross-sectional view of the developer cartridge 1 at the position of line AA in Figure 5.

[0017] The developing cartridge 1 comprises a housing 10, an agitator 17, a first bearing 18, a second bearing 19, a developing roller 20, a blade unit 23, a supply roller 25, a gear unit 30, a memory assembly 40, and a separation member 45.

[0018] <2-1. Enclosure> The housing 10 is a container capable of holding toner. The housing 10 has a first end face 11 and a second end face 12. The first end face 11 is located at one end of the housing 10 in a first direction. The second end face 12 is located at the other end of the housing 10 in a first direction. The first end face 11 and the second end face 12 are separated from each other in a first direction.

[0019] A toner storage chamber 13 is provided inside the housing 10. The toner is stored in the toner storage chamber 13. The housing 10 also has an opening 14. The 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 are in communication through the opening 14.

[0020] Figure 10 is an exploded perspective view of the housing 10 and agitator 17. As shown in Figure 10, the housing 10 has a first toner frame 15 and a second toner frame 16. The first toner frame 15 and the second toner frame 16 extend in a first direction. The first toner frame 15 and the second toner frame 16 are aligned in a third direction.

[0021] The second toner frame 16 is cup-shaped. Specifically, the second toner frame 16 is concave in the third direction, away from the first toner frame 15. The second toner frame 16 has the first end face 11 and the second end face 12 described above. The first toner frame 15 is plate-shaped. The first toner frame 15 covers the opening of the second toner frame 16.

[0022] The first toner frame 15 and the second toner frame 16 are fixed to each other. For example, the first toner frame 15 and the second toner frame 16 are fixed to each other by welding. However, the first toner frame 15 and the second toner frame 16 may also be fixed to each other by screws. The toner storage chamber 13 is the space surrounded by the first toner frame 15 and the second toner frame 16.

[0023] As shown in Figure 10, the housing 10 has a toner filling port 162 and a cap 163 that closes the toner filling port 162. The toner filling port 162 is located at one end of the second toner frame 16 in the first direction. Also, the toner filling port 162 is located further away from the developing roller 20 in the second direction than the multiple gears included in the gear unit 30. The toner filling port 162 penetrates the first end face 11 in the first direction. Toner is filled into the toner storage chamber 13 inside the housing 10 through the toner filling port 162.

[0024] As shown in Figures 4 and 6, the second toner frame 16 has a toner handle 161. The toner handle 161 is located at the other end of the housing 10 in the second direction. The toner handle 161 is also located in the center of the housing 10 in the first direction. The toner handle 161 is recessed in the second direction from the other end of the housing 10 toward the toner storage chamber 13 in the second direction. The toner handle 161 is also recessed in the third direction from the outer surface of the second toner frame 16 toward the first toner frame 15.

[0025] On the other hand, the first toner frame 15 has an anti-slip portion 158 on its outer surface. The anti-slip portion 158 has a shape in which multiple grooves extending in the first direction are arranged in the second direction. The anti-slip portion 158 and the toner handle 161 are aligned in the third direction. The dimension in the third direction from the toner handle 161 to the anti-slip portion 158 is smaller than the maximum dimension in the third direction of the housing 10. More specifically, the dimension in the third direction from the toner handle 161 to the anti-slip portion 158 is smaller than the maximum dimension in the third direction of the toner storage chamber 13.

[0026] The user of the developer cartridge 1 grasps the cartridge by gripping the toner handle 161 and the anti-slip portion 158. Because the gap between the toner handle 161 and the anti-slip portion 158 is smaller than that between other parts of the housing 10, the user can easily hold the developer cartridge 1. In addition, the anti-slip portion 158 prevents the user's fingers from slipping. Furthermore, by making the toner handle 161 concave rather than convex, the volume of the toner storage chamber 13 can be made larger in the areas other than the toner handle 161.

[0027] As shown in Figure 10, the housing 10 has two first inner bosses 164. The two first inner bosses 164 are located inside the housing 10. The two first inner bosses 164 are spaced apart in a first direction. The two first inner bosses 164 extend in a third direction from the inner surface of the toner handle 161 toward the first toner frame 15. The outer diameter of the first inner bosses 164 gradually decreases as it moves from the second toner frame 16 toward the first toner frame 15. The tips of the first inner bosses 164 contact the inner surface of the first toner frame 15.

[0028] The first inner boss 164 supports the toner handle 161 and the anti-slip portion 158 from the inside in a third direction. Therefore, even if the user grips the toner handle 161 and the anti-slip portion 158 with strong force, the first inner boss 164 suppresses the bending of the housing 10. Specifically, it can suppress the bending of the housing 10 so that the toner handle 161 and the anti-slip portion 158 come closer together. Thus, it can suppress the leakage of toner from inside the housing 10 to the outside due to the bending of the housing 10.

[0029] Furthermore, as shown in Figure 10, the housing 10 has two second inner bosses 165. The two second inner bosses 165 are located inside the housing 10. The two second inner bosses 165 are spaced apart in the first direction. The two second inner bosses 165 are located closer to the developing roller 20 in the second direction than the first inner boss 164. The two first inner bosses 164 are located between the two second inner bosses 165 in the first direction.

[0030] The second inner boss 165 extends in a third direction from the inner surface of the second toner frame 16 toward the first toner frame 15. The outer diameter of the second inner boss 165 gradually decreases as it moves from the second toner frame 16 toward the first toner frame 15. The tip of the second inner boss 165 is welded to the inner surface of the first toner frame 15.

[0031] The second inner boss 165 supports the first toner frame 15 and the second toner frame 16 from the inside in a third direction. This further suppresses the bending of the housing 10. Therefore, leakage of toner from inside the housing 10 to the outside due to the bending of the housing 10 is further suppressed.

[0032] As described above, the tip of the second inner boss 165 is welded to the inner surface of the first toner frame 15. In contrast, the tip of the first inner boss 164 is not welded to the inner surface of the first toner frame 15. This suppresses deformation of the housing 10 due to welding compared to when both the second inner boss 165 and the first inner boss 164 are welded to the first toner frame 15.

[0033] As shown in Figures 4 and 6, the second toner frame 16 has a convex portion 166. The convex portion 166 is a portion that bulges outward from the housing 10 in a third direction compared to the rest of the second toner frame 16. The convex portion 166 is located in the center of the housing 10 in a first direction. The convex portion 166 protrudes in a direction away from the first toner frame 15 in a second direction compared to both ends of the second toner frame 16 in a first direction. The space inside the convex portion 166 is part of the toner storage chamber 13. This allows for a larger volume of the toner storage chamber 13 than if the convex portion 166 were absent.

[0034] Furthermore, as shown in Figures 4 and 6, the second toner frame 16 has two positioning ribs 167. The two positioning ribs 167 are located at both ends of the convex portion 166 in the first direction. Each positioning rib 167 protrudes outward from the outer surface of the second toner frame 16. More specifically, the positioning ribs 167 protrude further outward from the outer surface of the convex portion 166. The positioning ribs 167 are plate-shaped and extend in the second direction.

[0035] With the developing cartridge 1 mounted on the drum unit 2, the positioning rib 167 contacts the drum frame 60 of the drum unit 2, which will be described later. This positions the housing 10 relative to the drum unit 2. More specifically, it determines the position of the housing 10 in the rotational direction around the developing roller 20.

[0036] Furthermore, as shown in Figures 4 and 6, the second toner frame 16 has two pressable portions 168. The two pressable portions 168 are located at both ends of the second toner frame 16 in a first direction. One pressable portion 168 is located between the convex portion 166 and the first end face 11 in the first direction. The other pressable portion 168 is located between the convex portion 166 and the second end face 12 in the first direction. The pressable portions 168 protrude outward from the outer surface of the second toner frame 16 in a third direction.

[0037] When the developing cartridge 1 is mounted on the drum unit 2, the pressed portion 168 comes into contact with the pressing member 64 of the drum unit 2, which will be described later. The pressing member 64 then presses the pressed portion 168 in a second direction toward the photoreceptor drum 50. As a result, the developing roller 20 is pressed against the photoreceptor drum 50.

[0038] <2-2. Agitator> The agitator 17 is a component that agitates the toner inside the housing 10. As shown in Figures 9 and 10, the agitator 17 has an agitator shaft 171 and agitator blades 172. The agitator shaft 171 extends in a first direction within the housing 10. The agitator shaft 171 is supported by the second toner frame 16 in a manner that allows it to rotate about the agitator axis extending in the first direction.

[0039] The agitator blades 172 spread radially outward from the agitator shaft 171. That is, the agitator blades 172 spread toward the inner surface of the housing 10. The tips of the agitator blades 172 contact the inner surface of the housing 10. For example, a flexible and deformable film is used for the agitator blades 172. The agitator 17 rotates around the agitator shaft by a driving force supplied from the image forming apparatus 100 via the gear unit 30. This causes the agitator blades 172 to agitate the toner inside the housing 10.

[0040] As shown in Figure 10, the agitator blade 172 has two agitator recesses 173. The agitator recesses 173 are recessed from the tip of the agitator blade 172 toward the agitator shaft 171. The two agitator recesses 173 are located in the same position as the first inner boss 164 in the first direction.

[0041] When the agitator 17 rotates, the two second inner bosses 165 come into contact with the agitator blades 172. In contrast, the two first inner bosses 164 pass through the agitator recesses 173. This prevents the agitator blades 172 from deforming due to contact with the first inner bosses 164. Therefore, toner present near the first inner bosses 164 can also be effectively agitated by the agitator blades 172. The agitator blades 172 may have slits instead of agitator recesses 173.

[0042] <2-3. First bearing> Figure 11 is an exploded perspective view of the housing 10, the first bearing 18, and the second bearing 19. The first bearing 18 is located on the first end face 11 of the housing 10. The first bearing 18 is a substantially plate-shaped member. The first bearing 18 extends in a direction intersecting the first direction. The first bearing 18 is attached to the first end face 11 of the housing 10 by screws 180. The first bearing 18 is a non-conductive member. Specifically, the first bearing 18 is formed of a resin which is an insulator.

[0043] As shown in Figure 11, the first bearing 18 has a first bearing hole 181 and a second bearing hole 182. The first bearing hole 181 and the second bearing hole 182 are circular holes that penetrate the first bearing 18 in a first direction. The first bearing hole 181 and the second bearing hole 182 are aligned in a second direction. The first bearing hole 181 is located closer to one end of the housing 10 in the second direction than the second bearing hole 182.

[0044] Furthermore, the first bearing 18 has a cylindrical coupling gear shaft 330. The coupling gear shaft 330 is located closer to the other end of the housing 10 in the second direction than the first bearing hole 181 and the second bearing hole 182. The coupling gear shaft 330 protrudes from the surface of the first bearing 18 in the first direction toward the opposite side of the housing 10. The first bearing 18 has a hole that penetrates the coupling gear shaft 330 in the first direction.

[0045] <2-4. Second bearing> The second bearing 19 is located on the second end face 12 of the housing 10. The second bearing 19 is a substantially plate-shaped member. The second bearing 19 extends in a direction intersecting the first direction. The second bearing 19 is attached to the second end face 12 of the housing 10 by screws 190. The second bearing 19 is a conductive member. Specifically, the second bearing 19 is made of a conductive resin.

[0046] As shown in Figure 11, the second bearing 19 has a third bearing hole 191 and a bearing recess 192. The third bearing hole 191 is a circular hole that penetrates the second bearing 19 in a first direction. The bearing recess 192 is a circular recess formed on the surface of the second bearing 19 facing the housing 10. The third bearing hole 191 and the bearing recess 192 are aligned in a second direction. The third bearing hole 191 is located closer to one end of the housing 10 in the second direction than the bearing recess 192.

[0047] <2-5. Developing Roller> The developing roller 20 is a roller that can rotate around a developing axis extending in a first direction. The developing roller 20 is located at the opening 14 of the housing 10. That is, the developing roller 20 is located at one end of the housing 10 in a second direction. As shown in Figure 1, the drum unit 2 has a photoreceptor drum 50. When the developing cartridge 1 is mounted on the drum unit 2, the developing roller 20 comes into contact with the photoreceptor drum 50.

[0048] Figure 12 is an exploded perspective view of the housing 10 and the developing roller 20. As shown in Figure 12, the developing roller 20 has a developing roller body 21 and a developing roller shaft 22. The developing roller body 21 is a cylindrical member extending in a first direction. The developing roller body 21 is made of, for example, elastic rubber. The developing roller shaft 22 is a cylindrical member that penetrates the developing roller body 21 and extends in a first direction. The developing roller body 21 is fixed to the developing roller shaft 22. The developing roller shaft 22 is made of metal or a conductive resin.

[0049] One end of the developing roller shaft 22 in the first direction is inserted into the first bearing hole 181 of the first bearing 18. The end of the developing roller shaft 22 is then supported by the cylindrical circumferential surface of the first bearing hole 181. The other end of the developing roller shaft 22 in the first direction is inserted into the third bearing hole 191 of the second bearing 19. The other end of the developing roller shaft 22 is then supported by the cylindrical circumferential surface of the third bearing hole 191. As a result, the developing roller 20 is supported by the housing 10 in a state where it can rotate around the developing axis.

[0050] The developing roller 20 rotates around the developing axis by a driving force supplied from the image forming apparatus 100 via the gear unit 30. The toner inside the housing 10 is carried on the outer surface of the developing roller 20.

[0051] As shown in Figure 3, the developing roller 20 has a collar 221. The collar 221 is mounted on the other end of the developing roller shaft 22 in the first direction. In the first direction, the collar 221 is located outside the second bearing 19. The collar 221 is a conductive material. Specifically, the collar 221 is made of a conductive resin. The collar 221 is in contact with the second bearing 19. The collar 221 is also in contact with the other end of the developing roller shaft 22 in the first direction. As a result, the second bearing 19 and the developing roller shaft 22 are electrically connected via the collar 221.

[0052] Furthermore, as shown in Figure 12, the developing roller 20 has a ring 222. The ring 222 is an annular plate. The ring 222 is mounted on the developing roller shaft 22. In a first direction, the ring 222 is positioned between the developing roller body 21 and the second bearing 19. In the first direction, one surface of the ring 222 contacts a stepped surface 223 formed on the developing roller shaft 22. In the first direction, the other surface of the ring 222 contacts the inner surface of the second toner frame 16.

[0053] If the developing cartridge 1 falls, a load in the first direction toward the second bearing 19 may be applied to the developing roller shaft 22. In that case, the load in the first direction of the developing roller shaft 22 is received by the second toner frame 16 via the ring 222. Therefore, the load in the first direction of the developing roller shaft 22 is not applied to the second bearing 19. This prevents excessive load from being applied to the second bearing 19.

[0054] As shown in Figure 12, the developer cartridge 1 has a toner film 211. The toner film 211 is a flexible and deformable film. The toner film 211 is located at the opening 14. One end of the toner film 211 is attached to the inner surface of the second toner frame 16. The other end of the toner film 211 is in contact with the outer surface of the developer roller 20. That is, the toner film 211 is interposed between the second toner frame 16 and the developer roller 20. This prevents toner from leaking from inside the housing 10 to the outside of the housing 10 through the space between the developer roller 20 and the second toner frame 16.

[0055] <2-6. Blade Unit> The blade unit 23 is a component for shaping the toner supported on the outer surface of the developing roller 20 to a predetermined thickness. The blade unit 23 is located in the opening 14 of the housing 10. Figure 13 is an exploded perspective view of the housing 10 and the blade unit 23. As shown in Figures 9 and 13, the blade unit 23 has a blade 231 and a blade holder 232.

[0056] The blade 231 extends in a first direction along the outer circumferential surface of the developing roller 20. The blade holder 232 is a member that holds the blade 231. The blade holder 232 is attached to the second toner frame 16. Specifically, both ends of the blade holder 232 in the first direction are fixed to the second toner frame 16 by screws 230. The blade 231 and the blade holder 232 are flexible.

[0057] In the third direction, one end of the blade 231 contacts the outer circumferential surface of the developing roller 20. More specifically, in the third direction, one end of the blade 231 contacts the toner supported on the outer circumferential surface of the developing roller 20. In the third direction, the other end of the blade 231 is attached to the blade holder 232. For example, in the third direction, the other end of the blade 231 is welded to the blade holder 232.

[0058] As the developing roller 20 rotates, a portion of the toner carried on the outer surface of the developing roller 20 is scraped off by the blade 231. This causes the toner carried on the outer surface of the developing roller 20 to be formed to a predetermined thickness.

[0059] Furthermore, as shown in Figures 9 and 13, the developing cartridge 1 includes a convex plate 24. The convex plate 24 is a plate for curving the blade unit 23. The convex plate 24 is attached to the outer surface of the first toner frame 15. Specifically, the convex plate 24 is fixed to the outer surface of the first toner frame 15 by screws 240.

[0060] The convex plate 24 has a curved surface 241 at one end in the second direction. The curved surface 241 is a surface that is curved in a convex shape toward the blade holder 232. That is, the central part of the curved surface 241 in the first direction protrudes toward the blade holder 232 more toward the blade holder 232 than the ends of the curved surface 241 in the first direction.

[0061] The curved surface 241 contacts the blade holder 232. As a result, the blade holder 232 and the blade 231 curve according to the shape of the curved surface 241. Then, by contacting the curved blade 231, the developing roller 20 also curves slightly. Specifically, the central part of the developing roller 20 in the first direction protrudes in a direction away from the blade 231 in the second direction, more so than the ends of the developing roller 20 in the first direction. As a result, when the developing cartridge 1 is mounted on the drum unit 2, the central part of the developing roller 20 in the first direction can be firmly in contact with the photosensitive drum 50.

[0062] Furthermore, as shown in Figures 9 and 13, the developer cartridge 1 has a sealing member 233. The sealing member 233 is a plate-shaped sponge extending in a first direction. The sealing member 233 is located between one end of the first toner frame 15 in a second direction and the blade holder 232. This prevents toner from leaking from inside the housing 10 through the space between the first toner frame 15 and the blade holder 232 to the outside of the housing 10.

[0063] <2-7. Supply Roller> The supply roller 25 is a roller that can rotate around a supply shaft extending in a first direction. The supply roller 25 is located inside the housing 10. More specifically, in a second direction, the supply roller 25 is located between the developing roller 20 and the agitator 17.

[0064] Figure 14 is an exploded perspective view of the housing 10 and the supply roller 25. As shown in Figure 14, the supply roller 25 has a supply roller body 26 and a supply roller shaft 27. The supply roller body 26 is a cylindrical member extending in a first direction. The supply roller body 26 is made of, for example, elastic rubber. The outer circumferential surface of the supply roller body 26 is in contact with the outer circumferential surface of the developing roller body 21. The supply roller shaft 27 is a cylindrical member that penetrates the supply roller body 26 and extends in a first direction. The supply roller body 26 is fixed to the supply roller shaft 27. The supply roller shaft 27 is made of metal or conductive resin.

[0065] One end of the supply roller shaft 27 in the first direction is inserted into the second bearing hole 182 of the first bearing 18. The end of the supply roller shaft 27 is then supported by the cylindrical circumferential surface of the second bearing hole 182. The other end of the supply roller shaft 27 in the first direction is inserted into the bearing recess 192 of the second bearing 19. The other end of the supply roller shaft 27 is then supported by the cylindrical circumferential surface of the bearing recess 192. As a result, the supply roller 25 is supported by the housing 10 in a state where it can rotate around the supply shaft.

[0066] Figure 15 is a partial cross-sectional view of the developing cartridge 1 near the other end of the supply roller shaft 27 in the first direction. As shown in Figure 15, the other end of the supply roller shaft 27 in the first direction contacts the second bearing 19 in the first direction. More specifically, the other end of the supply roller shaft 27 in the first direction contacts the surface of the second bearing 19 in the first direction within the bearing recess 192. This positions the supply roller shaft 27 in the first direction relative to the housing 10 and the second bearing 19. In addition, the second bearing 19 and the supply roller shaft 27 are electrically conductive.

[0067] The supply roller 25 rotates around the developing axis by a driving force supplied from the image forming apparatus 100 via the gear unit 30. Toner inside the housing 10 is supplied to the outer surface of the developing roller 20 via the outer surface of the supply roller 25.

[0068] <2-8. Gear Unit> The gear unit 30 is located on the first end face 11 of the housing 10. The gear unit 30 has a gear cover 31. The gear cover 31 is attached to the first end face 11 of the housing 10. Specifically, the gear cover 31 is fixed to the first end face 11 of the housing 10 by screws 310. The toner filling port 162 and cap 163 described above are covered by the gear cover 31.

[0069] Figure 16 is an exploded perspective view of the gear unit 30. Figure 17 is a view of the developing cartridge 1 with the gear cover 31 removed, seen from the gear cover 31 side in the first direction.

[0070] As shown in Figures 16 and 17, the gear unit 30 includes a coupling 32, a coupling gear 33, a supply roller gear 34, a first idler gear 35, a developing roller gear 36, a second idler gear 37, and an agitator gear 38. The coupling gear 33, supply roller gear 34, first idler gear 35, developing roller gear 36, second idler gear 37, and agitator gear 38 are located between the first end face 11 of the housing 10 and the gear cover 31 in a first direction. That is, the coupling gear 33, supply roller gear 34, first idler gear 35, developing roller gear 36, second idler gear 37, and agitator gear 38 are covered by the gear cover 31.

[0071] The coupling 32, coupling gear 33, supply roller gear 34, first idler gear 35, developing roller gear 36, second idler gear 37, and agitator gear 38 are each rotatable about an axis extending in the first direction.

[0072] The gear cover 31 has a cylindrical coupling holder 311. The coupling holder 311 protrudes from the outer surface of the gear cover 31 in a first direction toward the opposite side of the housing 10. A hole is formed inside the coupling holder 311 that penetrates the gear cover 31 in the first direction.

[0073] The coupling 32 is located inside the coupling holder 311 of the gear cover 31. Therefore, the coupling 32 is exposed to the outside from the gear cover 31. When the drum unit 2 with the developing cartridge 1 attached is mounted on the image forming apparatus 100, the drive shaft of the image forming apparatus 100 is connected to the coupling 32. Specifically, a projection of the drive shaft is inserted into a hole provided in the center of the coupling 32. When the drive shaft rotates, the coupling 32 also rotates together with the drive shaft.

[0074] The coupling gear 33 is a gear that rotates together with the coupling 32. In the first direction, the coupling gear 33 is located between the coupling 32 and the housing 10. In this embodiment, the coupling 32 and the coupling gear 33 are an integrated component. The first bearing 18 also has a coupling gear shaft 330. The coupling gear shaft 330 protrudes from the outer surface of the first bearing 18 in the first direction. The coupling gear shaft 330 is inserted inside the coupling gear 33. This allows the coupling gear 33 and the coupling 32 to be rotatably supported relative to the housing 10.

[0075] However, the coupling 32 and the coupling gear 33 may be separate parts. In that case, it is sufficient that the coupling 32 and the coupling gear 33 are fixed to each other.

[0076] The coupling gear 33 includes a small-diameter coupling gear 331 and a large-diameter coupling gear 332. The small-diameter coupling gear 331 and the large-diameter coupling gear 332 are aligned in a first direction. In the first direction, the large-diameter coupling gear 332 is located between the housing 10 and the small-diameter coupling gear 331. The diameter of the large-diameter coupling gear 332, centered on the coupling gear shaft 330, is larger than the diameter of the small-diameter coupling gear 331, centered on the coupling gear shaft 330.

[0077] The supply roller gear 34 is a gear that rotates the supply roller 25. One end of the supply roller shaft 27 in the first direction is connected to the supply roller gear 34. The supply roller gear 34 meshes with the large-diameter coupling gear 332. Therefore, when the coupling 32 rotates, the rotation is transmitted to the supply roller gear 34 via the large-diameter coupling gear 332. The supply roller 25 then rotates along the supply shaft together with the supply roller gear 34.

[0078] The first idler gear 35 is a gear that transmits rotation from the supply roller gear 34 to the developing roller gear 36. The first bearing 18 has a first idler gear shaft 350. The first idler gear shaft 350 protrudes in a first direction from the outer surface of the first bearing 18 toward the gear cover 31. The first idler gear shaft 350 is inserted into the central hole of the first idler gear 35. This rotatably supports the first idler gear 35 relative to the housing 10. The first idler gear 35 meshes with the supply roller gear 34.

[0079] The developing roller gear 36 is a gear that rotates the developing roller 20. One end of the developing roller shaft 22 in the first direction is connected to the developing roller gear 36. The developing roller gear 36 meshes with the first idler gear 35. Therefore, when the coupling 32 rotates, the rotation is transmitted to the developing roller gear 36 via the large-diameter coupling gear 332, the supply roller gear 34, and the first idler gear 35. The developing roller 20 then rotates with the developing roller gear 36 around the developing shaft.

[0080] The second idler gear 37 is a gear that transmits rotation from the coupling gear 33 to the agitator gear 38. The first bearing 18 has a second idler gear shaft 370. The second idler gear shaft 370 protrudes in a first direction from the outer surface of the first bearing 18 toward the gear cover 31. The second idler gear shaft 370 is inserted into the central hole of the second idler gear 37. This allows the second idler gear 37 to be rotatably supported relative to the housing 10.

[0081] The second idler gear 37 has a large-diameter second idler gear 371 and a small-diameter second idler gear 372. The large-diameter second idler gear 371 and the small-diameter second idler gear 372 are aligned in a first direction. In the first direction, the small-diameter second idler gear 372 is located between the housing 10 and the large-diameter second idler gear 371. The diameter of the small-diameter second idler gear 372, centered on the second idler gear shaft 370, is smaller than the diameter of the large-diameter second idler gear 371, centered on the second idler gear shaft 370. The large-diameter second idler gear 371 meshes with the small-diameter coupling gear 331.

[0082] The agitator gear 38 is the gear that rotates the agitator 17. One end of the agitator shaft 171 in the first direction is connected to the agitator gear 38. The agitator gear 38 meshes with the small-diameter second idler gear 372. Therefore, when the coupling 32 rotates, the rotation is transmitted to the agitator gear 38 via the small-diameter coupling gear 331 and the second idler gear 37. Then, together with the agitator gear 38, the agitator 17 rotates around the agitator shaft. As a result, the developer contained in the housing 10 is agitated.

[0083] The gears of the gear unit 30 may transmit rotational force by the meshing of teeth, or they may transmit rotational force by friction.

[0084] Figure 18 is a view of the area around the first end face 11 of the developing cartridge 1 with the gear cover 31 removed, seen from the second toner frame 16 side in the third direction. As shown in Figure 18, a portion of the coupling gear 33, the supply roller gear 34, the first idler gear 35, the developing roller gear 36, a portion of the second idler gear 37, and the agitator gear 38 are arranged in the same range R in the first direction. This allows the gear unit 30 to be made thinner in the first direction compared to when these gears are arranged in different positions in the first direction.

[0085] As described above, the coupling gear 33 is a two-stage gear including a small-diameter coupling gear 331 and a large-diameter coupling gear 332. This allows the coupling gear 33 to transmit rotations at different rotational speeds to the supply roller gear 34 and the second idler gear 37.

[0086] Furthermore, as described above, the second idler gear 37 is a two-stage gear including a large-diameter second idler gear 371 and a small-diameter second idler gear 372. This allows rotation to be transmitted from the coupling gear 33 to the agitator gear 38 via the second idler gear 37 with a variable speed.

[0087] Furthermore, as shown in Figure 18, the toner filling port 162 protrudes outward from the housing 10 in the first direction beyond the range R described above. That is, the toner filling port 162 protrudes outward from the housing 10 in the first direction beyond the supply roller gear 34, the first idler gear 35, the developer roller gear 36, and the agitator gear 38. This allows for a wider space to be secured inside the housing 10 beyond the toner filling port 162.

[0088] <2-9. Memory Assembly> The memory assembly 40 is located on the second end face 12 of the housing 10. The memory assembly 40 includes a memory 41, a holder 42, and a holder cover 43. Figure 19 is an exploded perspective view of the memory assembly 40. Figure 20 is a perspective view of the memory 41 and holder 42. Figure 21 is an exploded perspective view of the memory 41 and holder 42.

[0089] Memory 41 is a storage medium that stores information about the developing cartridge 1. Memory 41 is, for example, an IC chip. Memory 41 has an electrical contact surface 411. The electrical contact surface 411 is formed of a conductive metal. The electrical contact surface 411 is electrically connected to the memory elements of memory 41.

[0090] Memory 41 stores information regarding the specifications or lifespan of the developing cartridge 1. For example, memory 41 can store information indicating the lifespan of the developing roller 20. Specifically, memory 41 stores at least one of the following: the cumulative number of prints made by the developing roller 20, the cumulative number of rotations of the developing roller 20, and the amount of toner consumed. Memory 41 may also store information such as the serial number of the developing cartridge 1 and compatible models.

[0091] The memory 41 is held on the outer surface of the holder 42. Specifically, the memory 41 is held at one end of the holder 42 in the third direction. Therefore, the electrical contact surface 411 is located at one end of the holder 42 in the third direction. The electrical contact surface 411 extends in a direction intersecting the third direction. However, only the electrical contact surface 411 of the memory 41 may be held by the holder 42, and the memory elements of the memory 41 may be held by other parts of the developing cartridge 1.

[0092] The holder cover 43 is attached to the second end face 12 of the housing 10. Specifically, the holder cover 43 is fixed to the second end face 12 of the housing 10 by screws 430. The holder 42 is located between the second end face 12 of the housing 10 and the holder cover 43 in a first direction. At least a portion of the holder 42 is covered by the holder cover 43.

[0093] The holder 42 has a first boss 421, a second boss 422, and a third boss (not shown). The first boss 421 extends in a first direction toward the holder cover 43 from the surface of the holder 42 facing the holder cover 43. Meanwhile, the holder cover 43 has a first hole 431. The first hole 431 penetrates the holder cover 43 in a first direction. The first boss 421 is inserted into the first hole 431.

[0094] The second boss 422 and the third boss each extend in a first direction toward the housing 10 from the surface of the holder 42 facing the housing 10. Meanwhile, the housing 10 has a second hole 121 and a third hole 122. The second hole 121 and the third hole 122 are recesses formed in the second end face 12 of the housing 10. The second boss 422 is inserted into the second hole 121. The third boss is inserted into the third hole 122.

[0095] The shapes of the first boss 421, the second boss 422, and the third boss may be cylindrical, or they may be other shapes such as prismatics. The shapes of the first hole 431, the second hole 121, and the third hole 122 may be, for example, a roughly elliptical shape extending in the second direction.

[0096] The size of the first hole 431 in the second direction is larger than the size of the first boss 421 in the second direction. The size of the second hole 121 in the second direction is larger than the size of the second boss 422 in the second direction. The size of the third hole 122 in the second direction is larger than the size of the third boss in the second direction. Therefore, the holder 42, together with the first boss 421, the second boss 422, and the third boss, is movable in the second direction relative to the housing 10 and the holder cover 43. When the holder 42 moves in the second direction relative to the housing 10, the memory 41 having the electrical contact surface 411 also moves in the second direction relative to the housing 10 together with the holder 42.

[0097] The size of the first hole 431 in the third direction is larger than the size of the first boss 421 in the third direction. The size of the second hole 121 in the third direction is larger than the size of the second boss 422 in the third direction. The size of the third hole 122 in the third direction is larger than the size of the third boss in the third direction. Therefore, the holder 42, together with the first boss 421, the second boss 422, and the third boss, is movable in the third direction relative to the housing 10 and the holder cover 43. When the holder 42 moves in the third direction relative to the housing 10, the memory 41 having the electrical contact surface 411 also moves in the third direction relative to the housing 10 along with the holder 42.

[0098] Furthermore, the holder 42 is slightly movable in a first direction relative to the housing 10 and the holder cover 43 between the second end face 12 of the housing 10 and the holder cover 43. When the holder 42 moves in the first direction relative to the housing 10, the memory 41 having an electrical contact surface 411 also moves in the first direction relative to the housing 10 along with the holder 42.

[0099] As shown in Figure 21, the holder 42 has a first holder member 423, a second holder member 425, and a spring 427. The first holder member 423 and the second holder member 425 are formed of, for example, resin. The first holder member 423 has the first boss 421, the second boss 422, and the third boss described above.

[0100] The first holder member 423 has a first holder end 424. The first holder end 424 is one end of the holder 42 in the third direction. The memory 41 is attached to the first holder end 424. The second holder member 425 has a second holder end 426. The second holder end 426 is the other end of the holder 42 in the third direction. The first holder end 424 and the second holder end 426 are separated in the third direction. The first holder member 423 is movable in the third direction relative to the second holder member 425. Therefore, the first holder end 424 is movable in the third direction relative to the second holder end 426.

[0101] The spring 427 is an elastic member that can expand and contract in a third direction. The spring 427 is, for example, a coil spring. In the third direction, the spring 427 is located between the first holder end 424 and the second holder end 426. One end of the spring 427 in the third direction is connected to the first holder member 423. The other end of the spring 427 in the third direction is connected to the second holder member 425.

[0102] The spring 427 expands and contracts in a third direction between a first state and a second state that is more compressed than the first state. The length of the spring 427 in the third direction in the first state is longer than the length of the spring 427 in the third direction in the second state. Therefore, the distance in the third direction between the first holder end 424 and the second holder end 426 in the first state is longer than the distance in the third direction between the first holder end 424 and the second holder end 426 in the second state. Also, at least the length of the spring 427 in the third direction in the second state is shorter than the natural length of the spring 427.

[0103] Furthermore, as shown in Figure 21, the second holder member 425 has two holder claws 428. Each of the two holder claws 428 protrudes from the second holder member 425 in a direction intersecting the third direction. On the other hand, the first holder member 423 has two holder openings 429. The holder openings 429 penetrate a portion of the first holder member 423 in the first direction. The holder claws 428 are inserted into the holder openings 429.

[0104] When the spring 427 is in the first state, the holder claw 428 contacts the edge of the holder opening 429 in a third direction. This prevents the length of the spring 427 in the third direction from becoming longer than that of the first state. It also prevents the first holder member 423 and the second holder member 425 from separating. On the other hand, when the spring 427 is in the second state, the holder claw 428 moves away from the edge of the holder opening 429 in a third direction. This causes the holder 42 to contract in the third direction.

[0105] The first holder member 423 may have holder claws, and the second holder member 425 may have a holder opening.

[0106] In Figure 17, the position of the holder 42 is shown by a dashed line. As shown in Figure 17, the holder 42 overlaps with the toner filling port 162 in the first direction. That is, at least a portion of the holder 42 overlaps with a portion of the toner filling port 162 in the first direction. The holder 42 overlaps with the toner filling port 162 in the first direction regardless of its position within the movable range in the second and third directions.

[0107] In this way, by positioning a portion of the holder 42 and a portion of the toner filling port 162 to overlap in the first direction, the limited space on the first end face 11 and the second end face 12 of the housing 10 can be effectively utilized. Furthermore, the dimensions of the developer cartridge 1 in the second direction can be reduced compared to when the holder 42 and the toner filling port 162 are positioned in different locations in the second direction. Also, the dimensions of the developer cartridge 1 in the third direction can be reduced compared to when the holder 42 and the toner filling port 162 are positioned in different locations in the third direction. As a result, the developer cartridge 1 can be made smaller.

[0108] <2-10. Separating members> With the drum unit 2, which has four developing cartridges 1 installed, mounted on the image forming apparatus 100, the image forming apparatus 100 is capable of performing a separation operation on each developing cartridge 1. The separation operation is the movement of the developing roller 20 from a contact position to the photoreceptor drum 50 to a separation position to move away from the photoreceptor drum 50. The image forming apparatus 100 performs the separation operation on the developing cartridge 1 that is not being used. This causes the developing roller 20 of the unused developing cartridge 1 to be separated from the photoreceptor drum 50.

[0109] The separating member 45 is a member for switching the developing roller 20 between the contact position and the separated position described above. In other words, the separating member 45 is a member for switching the developing cartridge 1 mounted on the drum unit 2 from a state in which the developing roller 20 is in the contact position described above to a state in which the developing roller 20 is in the separated position described above.

[0110] Figure 22 is a perspective view of the developing cartridge 1 with the gear unit 30 removed. The separating member 45 is located between one end and the other end of the housing 10 in the second direction. As shown in Figure 22, the separating member 45 has a first cam 46, a second cam 47, and a separating shaft 48.

[0111] The separating member 45 is made of resin, for example. Specifically, the first cam 46, the second cam 47, and the separating shaft 48 are integrally molded from resin. However, the first cam 46, the second cam 47, and the separating shaft 48 may be separate parts. In that case, only the first cam 46 and the second cam 47 may be made of resin, and the separating shaft 48 may be made of metal.

[0112] Figure 23 is a perspective view of the developer cartridge 1 with the gear unit 30 and the separating member 45 removed. As shown in Figure 23, the housing 10 has a guide groove 151. The guide groove 151 is formed on the outer surface of the first toner frame 15. The guide groove 151 is recessed in a third direction from the outer surface of the first toner frame 15 toward the second toner frame 16. The guide groove 151 also extends in a first direction from one end of the first toner frame 15 in the first direction to the other end of the first toner frame 15 in the first direction.

[0113] As shown in Figure 16, the gear cover 31 has a shaft hole 312. The shaft hole 312 penetrates the gear cover 31 in a first direction at a position that overlaps with the guide groove 151 in a first direction. Also, as shown in Figure 19, the holder cover 43 has a shaft groove 432. The shaft groove 432 penetrates the holder cover 43 in a first direction at a position that overlaps with the guide groove 151 in a first direction.

[0114] The separation shaft 48 is positioned within the guide groove 151. The separation shaft 48 extends in a first direction along the guide groove 151. One end of the separation shaft 48 in the first direction is inserted into the shaft hole 312. This supports one end of the separation shaft 48 in the first direction with the gear cover 31. The other end of the separation shaft 48 in the first direction is inserted into the shaft groove 432. This supports the other end of the separation shaft 48 in the first direction with the holder cover 43.

[0115] The first cam 46 is located at one end of the separating member 45 in a first direction. The first cam 46 is located on the first end face 11 of the housing 10. The first cam 46 has a first inclined surface 461. The first inclined surface 461 is part of the circumferential surface centered on the separating shaft 48. The first inclined surface 461 is inclined with respect to a first direction. More specifically, the first inclined surface 461 is inclined so that as it approaches the other end of the separating member 45 in the first direction, it moves away from the developing roller 20 in the second direction.

[0116] The second cam 47 is located at the other end of the separating member 45 in the first direction. The second cam 47 is located at the second end face 12 of the housing 10. The second cam 47 has a second inclined surface 471. The second inclined surface 471 is part of the circumferential surface centered on the separating shaft 48. The second inclined surface 471 is inclined with respect to the first direction. More specifically, the second inclined surface 471 is inclined so that as it approaches the other end of the separating member 45 in the first direction, it moves away from the developing roller 20 in the second direction.

[0117] As shown in Figures 17 and 18, the separating member 45 has a positioning projection 462. The positioning projection 462 is located at one end of the separating member 45 in a first direction. The positioning projection 462 protrudes radially outward from the first cam 46 of the separating shaft 48. More specifically, the positioning projection 462 protrudes from the first cam 46 in a direction toward the developing roller 20 in a second direction. When the developing cartridge 1 is mounted on the drum unit 2, the positioning projection 462 contacts the inner surface of the first side frame 61 of the drum unit 2 (described later) in a first direction. This positions the separating member 45 relative to the drum unit 2 in a first direction.

[0118] The separating member 45 is movable in the first direction between a first position and a second position relative to the housing 10 and the developing roller 20. The first position is the position of the separating member 45 in the first direction when the positioning projection 462 is in contact with the first side frame 61 of the drum unit 2. Movement from the first position to the second position is movement in the direction from the first cam 46 to the second cam 47. In other words, the second position is the position in the first direction where the separating member 45 has moved to the other end side of the first position.

[0119] As shown in Figures 18 and 22, the separating member 45 has a spring support portion 463. The spring support portion 463 is located at one end of the separating member 45 in the first direction. The spring support portion 463 protrudes radially outward from the first cam 46 of the separating shaft 48. More specifically, the spring support portion 463 protrudes from the first cam 46 in the second direction, on the side opposite to the first inclined surface 461.

[0120] As shown in Figures 18, 22, and 23, the developing cartridge 1 has a return spring 49. The return spring 49 is an elastic member that can expand and contract in a first direction. For example, a coil spring is used for the return spring 49. The return spring 49 is located on the first end face 11 of the housing 10. The return spring 49 is covered by the gear cover 31. In the first direction, the return spring 49 is located between the first end face 11 of the housing 10 and the spring receiving portion 463.

[0121] The return spring 49 is located radially outward from the outer circumferential surface of the separation shaft 48, at a distance from it. One end of the return spring 49 in the first direction contacts the spring receiving portion 463. The other end of the return spring 49 in the first direction contacts the first end surface 11 of the housing 10. More specifically, the other end of the return spring 49 in the first direction contacts the second toner frame 16.

[0122] The return spring 49 is compressed in the first direction more than its natural length. Therefore, the return spring 49 biases the separating member 45 in the first direction, from the second position to the first position, due to its repulsive force. In other words, the return spring 49 biases the separating member 45 in the direction from the second cam 47 to the first cam 46. Consequently, the separating member 45 is in the first position when not subjected to external force.

[0123] As shown in Figures 16 and 22, the separating member 45 has a recess 464. The recess 464 is located at one end of the separating member 45 in the first direction. The recess 464 is adjacent to the first inclined surface 461 in the first direction. The recess 464 is located on the other end side of the separating member 45 in the first direction, relative to the first inclined surface 461. In addition, the recess 464 is located between the first developing guide roller 156 (described later) and the first inclined surface 461 in the first direction. In the second direction, the recess 464 is recessed away from the developing roller 20. This prevents the separating member 45 from contacting the drum frame 60 of the drum unit 2 (described later).

[0124] As shown in Figures 22 and 23, the housing 10 has a deflection prevention rib 152. The deflection prevention rib 152 is formed on the outer surface of the first toner frame 15. The deflection prevention rib 152 protrudes in a second direction toward the spaced shaft 48 from the edge of the guide groove 151. The deflection prevention rib 152 is located near the center of the guide groove 151 in the first direction.

[0125] The deflection-preventing rib 152 covers a portion of the separation shaft 48 positioned in the guide groove 151. This suppresses the separation shaft 48 from deflecting in a third direction toward the outside of the housing 10. In particular, when the separation shaft 48 is made of resin, its rigidity is lower than when the separation shaft 48 is made of metal, making it more prone to deflection. However, by covering the vicinity of the center of the separation shaft 48 in the first direction, the deflection-preventing rib 152 can suppress the vicinity of the center of the separation shaft 48 in the first direction from deflecting in a third direction toward the outside of the housing 10.

[0126] As shown in Figure 22, the separation shaft 48 has a thin-walled portion 481. The thin-walled portion 481 is located near the center of the separation shaft 48 in the first direction. The thickness of the thin-walled portion 481 in the third direction is thinner than the thickness of the portion of the separation shaft 48 other than the thin-walled portion 481 in the third direction. The deflection prevention rib 152 covers the thin-walled portion 481. This prevents the deflection prevention rib 152 from protruding from the outer surface of the housing 10 in the third direction.

[0127] Furthermore, as shown in Figure 22, the spaced shaft 48 has a notch 482. The notch 482 is a recess formed in a part of the thin-walled portion 481. The notch 482 penetrates the thin-walled portion 481 in a third direction. The length of the notch 482 in the first direction is longer than the length of the deflection prevention rib 152 in the first direction.

[0128] When attaching the separation member 45 to the housing 10, first, the separation shaft 48 is placed in the guide groove 151 with the deflection prevention rib 152 and the notch 482 overlapping in the third direction. That is, the separation shaft 48 is placed in the guide groove 151 with the deflection prevention rib 152 and the notch 482 in the same position in the first direction. This causes the deflection prevention rib 152 to pass through the notch 482 in the third direction. Then, the separation shaft 48 is moved relative to the housing 10 in the first direction. This causes the deflection prevention rib 152 and the notch 482 to be in different positions in the first direction. As a result, the deflection prevention rib 152 covers the thin-walled portion 481. Consequently, it is possible to prevent the separation shaft 48 from coming out of the guide groove 151.

[0129] Furthermore, as shown in Figures 22 and 23, the housing 10 has a molding groove 153. The molding groove 153 is formed on the outer surface of the first toner frame 15. The molding groove 153 is recessed in a third direction from the outer surface of the first toner frame 15 toward the second toner frame 16. The molding groove 153 extends in a second direction from the central part of the guide groove 151 in the first direction toward the developing roller 20. That is, the molding groove 153 extends away from the deflection prevention rib 152 in the second direction from the portion of the guide groove 151 that is covered by the deflection prevention rib 152. The width of the molding groove 153 in the first direction is greater than the width of the deflection prevention rib 152 in the first direction.

[0130] The first toner frame 15 is manufactured by injection molding. Specifically, the first toner frame 15 is formed by pouring molten resin into a cavity formed between two main cores that are assembled in a third direction, and allowing the resin to harden within the cavity. However, the main cores assembled in a third direction alone are insufficient to form the deflection prevention rib 152. Therefore, a slide core that moves in a second direction relative to the main core is used to form the deflection prevention rib 152.

[0131] The molding groove 153 is a groove formed by the slide core described above. During the molding of the first toner frame 15, after the resin filling the cavity in the main core has hardened, the slide core is removed in a second direction along the molding groove 153.

[0132] As shown in Figure 13, the first toner frame 15 has a screw boss 159. The screw boss 159 protrudes in a third direction from the outer surface of the first toner frame 15. The screw boss 159 has a screw hole through which a screw 240 for fixing the convex plate 24 is fastened. The molding groove 153 is located in a different position from the screw boss 159 in the first direction. Therefore, when the slide core is removed in the second direction, the slide core and the screw boss 159 do not interfere with each other.

[0133] As shown in Figure 23, the guide groove 151 has a first guide projection 154 and a second guide projection 155. The first guide projection 154 is located on the surface of the guide groove 151 on one side in the first direction relative to the molding groove 153. The second guide projection 155 is located on the surface of the guide groove 151 on the other side in the first direction relative to the molding groove 153. The first guide projection 154 and the second guide projection 155 protrude from the surface of the guide groove 151 in a third direction.

[0134] The separation shaft 48 does not contact the entire surface of the guide groove 151, but rather contacts the first guide projection 154 and the second guide projection 155. This reduces friction between the guide groove 151 and the separation shaft 48. In addition, the separation shaft 48 can be supported at two points separated in the first direction. Therefore, the posture of the separation shaft 48 can be stabilized. Furthermore, even if burrs are generated at the boundary between the main core and the slide core during the molding of the guide groove 151, contact between the separation shaft 48 and the burrs can be suppressed.

[0135] As shown in Figure 23, the second toner frame 16 has a first developing guide roller 156 and a second developing guide roller 157. The first developing guide roller 156 is located at one end of the second toner frame 16 in the first direction. The second developing guide roller 157 is located at the other end of the second toner frame 16 in the first direction. That is, the first developing guide roller 156 and the second developing guide roller 157 are separated in the first direction.

[0136] The first developing guide roller 156 is held in a groove formed on the outer surface of the second toner frame 16. The first developing guide roller 156 is rotatable about the first developing guide roller axis which intersects the first and second directions. The first developing guide roller 156 has a cylindrical outer surface centered on the first developing guide roller axis.

[0137] The outer surface of the first developing guide roller 156 contacts the separation shaft 48 in a second direction. As the separation shaft 48 moves in the first direction, the first developing guide roller 156 rotates around the axis of the first developing guide roller. This further reduces friction between the first toner frame 15 and the separation shaft 48.

[0138] The second developing guide roller 157 is held in a groove formed on the outer surface of the second toner frame 16. The second developing guide roller 157 is rotatable about the second developing guide roller axis which intersects the first and second directions. The second developing guide roller 157 has a cylindrical outer surface centered on the second developing guide roller axis.

[0139] The outer surface of the second developing guide roller 157 contacts the separation shaft 48 in a second direction. When the separation shaft 48 moves in the first direction, the second developing guide roller 157 rotates around the second developing guide roller axis. This further reduces friction between the first toner frame 15 and the separation shaft 48.

[0140] <3. Drum Unit Configuration> Next, the configuration of the drum unit 2 will be explained. Figure 24 is a perspective view of the drum unit 2. Figure 25 is a perspective view of the drum unit 2 with four developing cartridges 1 installed. The drum unit 2 comprises four photosensitive drums 50 and a drum frame 60.

[0141] <3-1. Photoconductor Drum> The photoreceptor drum 50 is located at one end of the drum unit 2 in the second direction. The four photoreceptor drums 50 are arranged in the third direction. Each of the four photoreceptor drums 50 corresponds to one of the four developing cartridges 1.

[0142] The photoreceptor drum 50 is supported by a drum frame 60. The photoreceptor drum 50 is rotatable about a drum axis extending in a first direction. The photoreceptor drum 50 has a cylindrical outer surface centered on the drum axis. The outer surface of the photoreceptor drum 50 is covered with a photosensitive material. When the developing cartridge 1 is mounted on the drum unit 2, the outer surface of the developing roller 20 comes into contact with the outer surface of the photoreceptor drum 50.

[0143] <3-2. Drum Frame> The drum frame 60 is a frame that supports the photoreceptor drum 50. As shown in Figure 24, the drum frame 60 has a first side frame 61, a second side frame 62, and four charging frames 63.

[0144] The first side frame 61 is located at one end of the drum frame 60 in a first direction. The first side frame 61 extends along the second and third directions. The first side frame 61 has a plurality of plates. For example, the first side frame 61 has a metal plate and a resin side plate that covers the outer surface of the metal plate.

[0145] The second side frame 62 is located at the other end of the drum frame 60 in the first direction. The second side frame 62 extends along the second and third directions. The second side frame 62 has a plurality of plates. For example, the second side frame 62 has a metal plate and a resin side plate that covers the outer surface of the metal plate.

[0146] The four charging frames 63 are arranged in a third direction. The four charging frames 63 correspond to each of the four developing cartridges 1. Each charging frame 63 extends in a first direction between the first side frame 61 and the second side frame 62. One end of the charging frame 63 in the first direction is fixed to the first side frame 61. The other end of the charging frame 63 in the first direction is fixed to the second side frame 62. The charging frames 63 are formed of, for example, resin. The photoreceptor drum 50 is supported in a rotatable manner relative to the charging frames 63. A charger (not shown) is also attached to the charging frame 63.

[0147] When the developing cartridge 1 is mounted on the drum unit 2, the housing 10 of the developing cartridge 1 is positioned between the first side frame 61 and the second side frame 62 in a first direction.

[0148] Furthermore, as shown in Figure 24, the drum unit 2 has a pressing member 64. When the developing cartridge 1 is mounted on the drum unit 2, the pressing member 64 comes into contact with the pressed portion 168 of the developing cartridge 1. The pressing member 64 then presses the pressed portion 168 of the developing cartridge 1 in a second direction by a spring (not shown). More specifically, the pressing member 64 presses the pressed portion 168 toward the photoreceptor drum 50. This causes the developing roller 20 to be pressed against the photoreceptor drum 50. As a result, the developing roller 20 and the photoreceptor drum 50 can be brought into contact.

[0149] <4. Regarding the action of separating> Next, the separation operation of the image forming apparatus 100 will be explained. Figures 26 and 27 are cross-sectional views of the drum unit 2, to which the developing cartridge 1 is mounted, including the separation member 45. Figure 26 shows the state in which the separation member 45 is in the first position and no separation operation is being performed. Figure 27 shows the state in which the separation member 45 is in the second position and the separation operation is being performed.

[0150] As shown in Figures 26 and 27, the image forming apparatus 100 has a pressing shaft 102. When the drum unit 2, which has four developing cartridges 1 mounted on it, is mounted on the main frame 101, the pressing shaft 102 faces the first cam 46 of the developing cartridge 1 in a first direction.

[0151] The pressing shaft 102 is movable in a first direction between a retracted position (position in Figure 26) and a protruding position (position in Figure 27) that is closer to the developing cartridge 1 than the retracted position. When the image forming apparatus 100 performs a separation operation, it moves the pressing shaft 102 from the retracted position to the protruding position. As a result, the pressing shaft 102 comes into contact with the first cam 46. The pressing shaft 102 then presses the separation member 45 in the first direction, from the first cam 46 toward the second cam 47. As a result, the return spring 49 compresses, causing the separation member 45 to move from the first position to the second position relative to the housing 10 in the first direction.

[0152] When the separating member 45 moves from the first position to the second position, the first inclined surface 461 of the first cam 46 moves in the first direction while contacting the drum frame 60. At this time, the first cam 46 moves in the second direction relative to the drum unit 2 due to the resistance force it receives from the drum frame 60. More specifically, the first cam 46 moves away from the photoreceptor drum 50 relative to the drum unit 2 due to the resistance force it receives from the drum frame 60.

[0153] Similarly, when the separating member 45 moves from the first position to the second position, the second inclined surface 471 of the second cam 47 moves in the first direction while contacting the drum frame 60. At this time, the second cam 47 moves in the second direction relative to the drum unit 2 due to the resistance force it receives from the drum frame 60. More specifically, the second cam 47 moves away from the photoreceptor drum 50 relative to the drum unit 2 due to the resistance force it receives from the drum frame 60.

[0154] As a result, the housing 10 and the developing roller 20 move in a second direction relative to the drum unit 2, together with the separating member 45. More specifically, the housing 10 and the developing roller 20 move away from the photoreceptor drum 50 relative to the drum unit 2. Consequently, the developing roller 20 moves in a second direction from a contact position where it is in contact with the photoreceptor drum 50 to a separated position where it is away from the photoreceptor drum 50.

[0155] The separation shaft 48 contacts the first developing guide roller 156 and the second developing guide roller 157. Therefore, during the separation operation described above, the first developing guide roller 156 and the second developing guide roller 157 receive a load from the separation shaft 48 in the second direction.

[0156] In this structure, of the first toner frame 15 and second toner frame 16 of the housing 10, the second toner frame 16 that supports the developing roller 20 has a first developing guide roller 156 and a second developing guide roller 157. Therefore, during the separation movement described above, the second toner frame 16 that supports the developing roller 20 receives a load in the second direction from the separation shaft 48. As a result, the developing roller 20 can be moved accurately in the second direction relative to the drum unit 2, without depending on the fixing accuracy of the first toner frame 15 and the second toner frame 16 or the dimensional accuracy of the first toner frame 15.

[0157] Even if the first toner frame 15 and the second toner frame 16 are precisely fixed together, a slight amount of play remains between the two frames. Furthermore, even if the first toner frame 15 is precisely molded, it has slight dimensional tolerances. If, during the separation operation, the separation shaft 48 pushes the first toner frame 15, the movement of the separation shaft 48 in the second direction is transmitted to the developing roller 20 via the first toner frame 15 and the second toner frame 16. In this case, the amount of movement of the developing roller 20 changes due to the aforementioned play and dimensional tolerances. However, as described above, if the separation shaft 48 pushes the second toner frame 16 during the separation operation, the movement of the separation shaft 48 in the second direction is transmitted to the developing roller 20 via the second toner frame 16 without going through the first toner frame 15. Therefore, the amount of movement of the developing roller 20 is not affected by the aforementioned play and dimensional tolerances. Consequently, the developing roller 20 can be moved precisely in the second direction relative to the drum unit 2.

[0158] In particular, the outer surface of the first developing guide roller 156 rotates in accordance with the movement of the separation shaft 48 in the first direction. Similarly, the outer surface of the second developing guide roller 157 rotates in accordance with the movement of the separation shaft 48 in the first direction. This reduces the frictional resistance of the separation shaft 48 against the second toner frame 16. Therefore, the separation shaft 48 can be moved with precision in the first direction relative to the housing 10.

[0159] Furthermore, in this embodiment, the first developing guide roller 156 and the second developing guide roller 157, which are separated in the first direction, receive a load in the second direction from the separating shaft 48 at two locations. This allows the developing rollers 29 to be separated from the photoreceptor drum 50 while suppressing the tilting of the developing cartridge 1 relative to the drum unit 2.

[0160] <5. Variation> Although one embodiment has been described above, this disclosure is not limited to the above embodiment.

[0161] In the above embodiment, the number of developing cartridges 1 that could be installed in the drum unit 2 was four. However, the number of developing cartridges 1 that could be installed in the drum unit 2 could be one to three, or five or more.

[0162] Furthermore, the shapes of the developing cartridge and drum unit may differ in detail from those shown in the figures of this application. In addition, the elements that appear in the above embodiments and modifications may be appropriately selected and omitted to the extent that no inconsistencies arise. [Explanation of symbols]

[0163] 1: Developing cartridge 2: Drum Unit 10: Cabinet 15: First toner frame 16: Second toner frame 17: Agitator 18: First bearing 19: Second bearing 20: Developing Roller 23: Blade Unit 25: Supply roller 30: Gear Unit 40: Memory Assembly 45: Separating member 50: Photoconductor drum 60: Drum frame 100: Image forming apparatus

Claims

[Claim 1] It is a casing, A toner storage chamber for storing toner, A toner filling port located at one end in the first direction, comprising a toner filling port for filling the toner into the toner storage chamber, A housing having, A developing roller rotatable about an axis extending in the first direction, the developing roller located at one end of the housing in a second direction intersecting the first direction, A cap attached to one end of the housing in the first direction, the cap covering the toner filling port, A separating member that is movable in the first direction relative to the housing, A spacing shaft extending in the first direction, A first inclined surface located at one end of the separating member in the first direction, wherein as it approaches the other end of the separating member in the first direction, the first inclined surface moves away from the developing roller in the second direction, A separating member having, A memory having an electrical contact surface, A holder located at the other end of the housing in the first direction, the holder which movably holds the electrical contact surface relative to the housing, Equipped with, The developer cartridge is characterized in that the holder overlaps with the toner filling port in the first direction.

Images