Image forming apparatus

Abstract

The present invention provides an image forming apparatus that can suppress the increase in size of the process cartridge and prevent unnecessary friction between the electrical contact surface and the main body contacts during the process of mounting the process cartridge into the apparatus body. [Solution] The image forming apparatus comprises a main body 21, a main body contact 210, and a process cartridge 5 having a developing unit 7 and a drum unit 6. The developing unit 7 comprises a memory 110 having an electrical contact surface 111 and a holder 120 movable relative to a developing frame 75. The holder 120 has a first end 121 that holds the memory 110 and a second end 122. The drum frame 65 of the drum unit 6 has a receiving portion 65E that the second end 122 can contact. When the process cartridge 5 is mounted on the main body 21, the receiving portion 65E contacts the second end 122 to restrict the movement of the holder 120, and the electrical contact surface 111 is below the photosensitive drum 61 and in contact with the main body contact 210.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus.

Background Art

[0002] As an image forming apparatus, one including an apparatus main body and a process cartridge detachable from the apparatus main body is known (Patent Document 1). In this technology, the process cartridge includes a drum unit and a developing unit attachable to the drum unit. The developing unit includes a memory having an electrical contact surface. The electrical contact surface contacts a main body contact in the apparatus main body when the process cartridge is attached to the apparatus main body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when a memory is provided in the developing unit, the process cartridge may be enlarged. Further, there is a possibility that the electrical contact surface of the memory and the main body contact may be rubbed unnecessarily during the process of attaching the process cartridge to the apparatus main body.

[0005] Therefore, it is desired to be able to suppress the enlargement of the process cartridge and suppress the unnecessary rubbing of the electrical contact surface and the main body contact during the process of attaching the process cartridge to the apparatus main body.

Means for Solving the Problems

[0006] The image forming apparatus includes an apparatus main body, a main body contact, and a process cartridge. The process cartridge is detachable from the main unit of the device. The process cartridge includes a developing unit and a drum unit. The developing unit comprises a developing roller, a developing frame, a memory, and a holder. The developing roller is rotatable about a developing roller axis that extends in a first direction. The developing frame holds the developing roller. The memory has an electrical contact surface. The holder holds the memory. The holder is movable relative to the development frame. The drum unit comprises a photosensitive drum and a drum frame. The photosensitive drum is rotatable about a drum axis that extends in a first direction. The drum frame holds the photosensitive drum. The holder has a first end and a second end. The first end holds the memory. The second end is separated from the first end in a second direction that intersects the first direction. The drum frame has a receiving portion that can be contacted at its second end. With the process cartridge mounted on the main body of the device, the receiving part contacts the second end to restrict the movement of the holder. With the process cartridge installed in the main unit, the electrical contact surface is below the photosensitive drum and contacts the main unit's contacts.

[0007] The drum frame has a receiving portion that restricts the movement of the holder, allowing the holder to be made smaller and thus preventing the process cartridge from becoming larger. Furthermore, when the process cartridge is mounted on the main unit, the electrical contact surface contacts the main unit contacts below the photosensitive drum, which prevents unnecessary friction between the electrical contact surface and the main unit contacts during the process cartridge mounting process cartridge onto the main unit.

[0008] The developing unit may further include an elastic member that biases the electrical contact surface toward the main body contacts when the process cartridge is mounted in the main body of the device.

[0009] The developing unit can stabilize contact between the electrical contact surface and the main body contact by including an elastic member that biases the electrical contact surface toward the main body contact.

[0010] With the process cartridge installed in the main unit, the developing roller may be positioned below the photosensitive drum, and the main unit contacts may also be positioned below the developing roller.

[0011] By positioning the developing roller below the photosensitive drum, and the main unit contacts below the developing roller, unnecessary friction between the electrical contact surface and the main unit contacts can be further suppressed during the process cartridge installation into the device body.

[0012] The device body may have a guide, and the body contacts may be located below the guide. The guide helps to move the process cartridge when it is being installed.

[0013] The main body of the apparatus has an opening on its top surface, and the image forming apparatus may further include a top cover. The top cover is movable between a closed position that closes the opening and an open position that opens the opening. The process cartridge may be removable from the main body of the device through an opening when the top cover is in the open position.

[0014] The process cartridge can be attached to and detached from the device body through an opening on the top surface of the device body, allowing the process cartridge to be installed from top to bottom. This further reduces unnecessary friction between the electrical contact surface and the device body contacts during the installation of the process cartridge into the device body.

[0015] The main contacts can be facing upwards.

[0016] The process cartridge can be mounted from above downward, and since the main body contacts face upward, it is possible to further suppress unnecessary rubbing between the electrical contact surface and the main body contacts during the mounting of the process cartridge to the apparatus main body.

[0017] The top cover is rotatable about a cover shaft extending in the first direction between a closed position and an open position, and the main body contacts may be inclined with respect to a horizontal plane so as to face the cover shaft side.

[0018] By inclining the upward-facing main body contacts with respect to the horizontal plane so as to further face the cover shaft side of the top cover, it is possible to make it difficult to touch the main body contacts in a state where the top cover is in the open position.

[0019] In a state where the process cartridge is mounted to the apparatus main body, the main body contacts and the receiving portion may face each other in the second direction.

[0020] When viewed from the first direction, the main body contacts may be located below a straight line passing through the contact portion between the receiving portion and the second end portion and the drum shaft. When viewed from the first direction, the photosensitive drum rotates in a rotational direction in which the electrical contact surface approaches the main body contacts.

[0021] When viewed from the first direction, the main body contacts are located below a straight line passing through the contact portion between the receiving portion and the second end portion and the drum shaft, and the photosensitive drum rotates in a rotational direction in which the electrical contact surface approaches the main body contacts, so that when the photosensitive drum rotates, the electrical contact surface can be pressed against the main body contacts.

[0022] The main body contacts are located inside the guide in the first direction, and the holder may be located within the width of the drum frame in the first direction.

[0023] Since the main body contacts are located inside the guide in the first direction and the holder is located within the width of the drum frame in the first direction, it is possible to further suppress an increase in size of the process cartridge.

[0024] The developing frame has a boss extending in a first direction, and the holder has a hole into which the boss can fit, and may be movable relative to the developing frame with the boss in the hole.

[0025] The holder comprises a first holder having a first end and a second holder having a second end, and the elastic member may be a compression spring located between the first holder and the second holder.

[0026] The developing unit may be detachable from the drum unit. [Effects of the Invention]

[0027] This design helps to suppress the increasing size of the process cartridge and also prevents unnecessary friction between the electrical contact surface and the main body contacts during the process of installing the process cartridge into the device body. [Brief explanation of the drawing]

[0028] [Figure 1] This is a diagram showing the schematic configuration of an image forming apparatus. [Figure 2] This diagram shows the main unit of the device and the process cartridge with the top cover in the open position. [Figure 3] This is a perspective view showing the process cartridge. [Figure 4] This is a perspective view showing the developing unit and drum unit. [Figure 5] This is an exploded perspective view showing an enlarged view of one end of the developing unit in the first direction. [Figure 6] This is a view of the developing unit with the gear cover removed, seen from one side in the first direction. [Figure 7] These are perspective views showing the memory, holder, and elastic components, with (a) showing the assembled state and (b) showing the disassembled state. [Figure 8] This is a cross-sectional view showing the holder and receiving portion of a process cartridge. [Figure 9] This is a cross-sectional view showing the main body contacts of the device. [Figure 10] This is a perspective view showing the device body with the top cover in the open position. [Figure 11] This is a cross-sectional view showing the process cartridge installed in the main unit of the device. [Figure 12] These are cross-sectional diagrams (a) and (b) illustrating the attachment of the developing unit to the drum unit. [Figure 13] Figures 12 and 12 show cross-sectional views (a) and (b) illustrating the attachment of the developing unit to the drum unit. [Figure 14] This is a cross-sectional view illustrating the installation of a process cartridge into the main body of the device. [Figure 15] This is a cross-sectional view following Figure 14, illustrating the installation of the process cartridge onto the main body of the device. [Figure 16] This is a cross-sectional view following Figure 15, illustrating the installation of the process cartridge onto the main body of the device. [Figure 17] This is a cross-sectional view following Figure 16, illustrating the installation of the process cartridge onto the main body of the device. [Modes for carrying out the invention]

[0029] Next, embodiments will be described. As shown in Figure 1, the image forming apparatus 1 is a printer that forms images on a sheet S such as paper. The image forming apparatus 1 comprises an apparatus body 21, a top cover 22, a sheet supply unit 3, an exposure unit 4, a process cartridge 5, a fixing unit 8, and an ejection roller 9. The apparatus body 21 has an opening 21A on its upper surface (see also Figure 2).

[0030] The top cover 22 opens and closes the opening 21A of the apparatus body 21. More specifically, the top cover 22 is movable relative to the apparatus body 21 between a closed position shown in Figure 1 and an open position shown in Figure 2. The closed position is the position that closes the opening 21A. The open position is the position that opens the opening 21A. The top cover 22 is rotatable between the closed position and the open position about a cover axis 22X that extends in a first direction. In this embodiment, the first direction corresponds to the left-right direction of the image forming apparatus 1. As shown in Figure 1, the top cover 22 has an output tray 22A on its upper surface when it is in the closed position.

[0031] The sheet supply unit 3 is located in the lower part of the main body 21 of the apparatus. The sheet supply unit 3 comprises a sheet tray 31, a pressing plate 32, and a sheet supply mechanism 33. The sheet tray 31 holds the sheets S. The pressing plate 32 pushes the rear of the sheets S in the sheet tray 31 upward. The sheet supply mechanism 33 supplies the sheets S to the process cartridge 5.

[0032] The exposure unit 4 is located above the sheet tray 31. The exposure unit 4 includes a light source, a deflector, a lens, a mirror, and the like.

[0033] The process cartridge 5 is detachable from the main unit 21 of the apparatus. More specifically, the process cartridge 5 is detachable from the main unit 21 of the apparatus through the opening 21A when the top cover 22 is in the open position (see Figure 2). When installed in the main unit 21 of the apparatus, the process cartridge 5 is located above the sheet supply mechanism 33. The process cartridge 5 includes a drum unit 6 and a developing unit 7.

[0034] The drum unit 6 comprises a photosensitive drum 61, a charger 62, a transfer roller 63, and a drum frame 65. The photosensitive drum 61 is rotatable about a drum shaft 61X extending in a first direction. The transfer roller 63 is rotatable about a transfer roller shaft 63X extending in a first direction. The drum frame 65 holds the photosensitive drum 61, the charger 62, and the transfer roller 63.

[0035] The developing unit 7 comprises a developing roller 71, a supply roller 72, a layer thickness regulating blade 73, an agitator 74, and a developing frame 75. The developing roller 71 is rotatable about a developing roller shaft 71X extending in a first direction. The supply roller 72 is rotatable about a supply roller shaft 72X extending in a first direction. The layer thickness regulating blade 73 regulates the thickness of the toner layer on the developing roller 71 to a constant thickness.

[0036] The developing frame 75 holds the developing roller 71, the supply roller 72, the layer thickness regulating blade 73, and the agitator 74. The developing frame 75 is capable of accommodating toner. Specifically, the developing frame 75 has a toner storage section 76 capable of accommodating toner.

[0037] The agitator 74 is rotatable about an agitator shaft 74X extending in a first direction. By rotating, the agitator 74 agitates the toner in the toner storage section 76. The supply roller 72 supplies toner to the developing roller 71.

[0038] The fixing unit 8 is located above the process cartridge 5. The fixing unit 8 includes a heating roller 81 and a pressure roller 82. The heating roller 81 heats the sheet S. The pressure roller 82 sandwiches the sheet S between itself and the heating roller 81.

[0039] The charger 62 charges the surface of the photosensitive drum 61. The exposure unit 4 emits a light beam onto the charged surface of the photosensitive drum 61 as shown by the dashed lines, exposing the surface of the photosensitive drum 61. This forms an electrostatic latent image on the photosensitive drum 61 based on the image data. The developing roller 71 supplies toner to the exposed photosensitive drum 61. This forms a toner image on the photosensitive drum 61.

[0040] The photosensitive drum 61 and transfer roller 63 transport the sheet S supplied from the sheet supply unit 3. This transfers the toner image formed on the photosensitive drum 61 to the sheet S. The heating roller 81 and pressure roller 82 transport the sheet S on which the toner image has been transferred. This fixes the toner image transferred to the sheet S.

[0041] The discharge roller 9 discharges the sheet S on which the toner image has been fixed into the discharge tray 22A.

[0042] As shown in Figures 3 and 4, the developing unit 7 is detachable from the drum unit 6. The drum unit 6 further comprises a shaft 61S. The shaft 61S is made of metal. The shaft 61S extends in a first direction. The shaft 61S is positioned along the drum axis 61X. Both ends of the shaft 61S in the first direction each protrude outward in the first direction from the end face of the drum frame 65 in the first direction.

[0043] The drum frame 65 has a first side wall 65A, a second side wall 65B, a connecting wall 65C (see Figure 4), and a pair of guided bosses 65D. The first side wall 65A is a wall located at one end of the drum frame 65 in a first direction. The second side wall 65B is a wall located at the other end of the drum frame 65 in a first direction. The first side wall 65A and the second side wall 65B face each other at a distance in a first direction.

[0044] The connecting wall 65C is a wall that connects the first side wall 65A and the second side wall 65B. The connecting wall 65C extends in the first direction. The guided boss 65D extends in the first direction. The guided boss 65D located in one direction of the first direction protrudes outward from the first side wall 65A in the first direction. The guided boss 65D located in the other direction of the first direction protrudes outward from the second side wall 65B in the first direction.

[0045] As shown in Figure 5, the developing unit 7 further comprises a gear train 77, a gear cover 78, a memory 110, a holder 120, and an elastic member 130 (see Figure 6).

[0046] The gear train 77 transmits the driving force supplied from the apparatus body 21 to the developing roller 71, the supply roller 72, and the agitator 74 when the process cartridge 5 is mounted on the apparatus body 21. As shown in Figure 6, the gear train 77 includes a coupling gear 77A, a developing roller gear 77B, a supply roller gear 77C, an idler gear 77D, and an agitator gear 77E.

[0047] The developing roller gear 77B is fixed to one end of the developing roller 71 in the first direction. The developing roller 71 rotates around the developing roller shaft 71X as the developing roller gear 77B rotates.

[0048] The supply roller gear 77C is fixed to one end of the supply roller 72 in the first direction. The supply roller 72 rotates around the supply roller shaft 72X as the supply roller gear 77C rotates.

[0049] The agitator gear 77E is fixed to one end of the agitator 74 in the first direction. The agitator 74 rotates around the agitator shaft 74X as the agitator gear 77E rotates.

[0050] The coupling gear 77A is a gear to which driving force is supplied from the main body 21 of the device. The coupling gear 77A meshes with the developing roller gear 77B and the supply roller gear 77C. In addition, the coupling gear 77A meshes with the agitator gear 77E via the idler gear 77D. The developing roller gear 77B, the supply roller gear 77C, and the agitator gear 77E rotate together with the coupling gear 77A as driving force is supplied to the coupling gear 77A.

[0051] As shown in Figure 5, the gear cover 78 is a cover that covers the gear train 77 and the holder 120. The gear cover 78 is fixed to one end of the developing frame 75 in the first direction by a number of screws 79.

[0052] Memory 110 is a storage medium that stores information about the developing unit 7. For example, memory 110 is an IC chip. Memory 110 stores at least one of the identification information and lifespan information of the developing unit 7. The identification information is information for identifying the developing unit 7. For example, the identification information is the serial number of the developing unit 7. The lifespan information is information that represents the lifespan of the developing unit 7. For example, the lifespan information is the cumulative number of rotations of the developing roller 71.

[0053] The memory 110 has an electrical contact surface 111. The electrical contact surface 111 is a metal surface that is a conductor. The electrical contact surface 111 is electrically connected to the memory elements of the memory 110. The electrical contact surface 111 is a surface that intersects in a second direction. The second direction is a direction that intersects in a first direction. In this embodiment, the second direction is a direction perpendicular to the first direction. In this embodiment, the electrical contact surface 111 is a surface perpendicular to the second direction.

[0054] With the developing unit 7 mounted on the drum unit 6, the electrical contact surface 111 is exposed from the drum frame 65 (see Figure 3). With the process cartridge 5 mounted on the main body 21 of the device, the electrical contact surface 111 contacts the main body contacts 210 of the image forming apparatus 1 (see Figure 11). This enables the control unit of the image forming apparatus 1 to communicate with the memory 110.

[0055] The electrical contact surface 111 contacts the main body contact 210 while the process cartridge 5 is being mounted onto the device body 21. In other words, the electrical contact surface 111 contacts the main body contact 210 before the process cartridge 5 is mounted onto the device body 21. In this embodiment, the electrical contact surface 111 contacts the main body contact 210 just before the process cartridge 5 is mounted onto the device body 21.

[0056] As shown in Figure 7(a), the holder 120 is a unit that holds the memory 110. The holder 120 has a first end 121 and a second end 122. The second end 122 is an end that is separated from the first end 121 in a second direction. In this embodiment, the first end 121 is one end of the holder 120 in the second direction. The second end 122 is the other end of the holder 120 in the second direction.

[0057] As shown in Figures 7(a) and 7(b), the holder 120 has a first holder 120A and a second holder 120B. The first holder 120A is a member that holds the memory 110. The first holder 120A has a first end 121. The memory 110 is located at the first end 121. In other words, the electrical contact surface 111 is located at the first end 121.

[0058] The second holder 120B is a member that holds the first holder 120A so that it can move in a second direction. The second holder 120B has a second end portion 122.

[0059] In this embodiment, the first holder 120A has a cup shape that opens toward the second holder 120B. The second holder 120B is inserted inside the first holder 120A. The first holder 120A has a pair of engagement holes 123 (only one is shown). The engagement holes 123 penetrate in a first direction. The second holder 120B has a pair of claws 124. The tips of the claws 124 protrude in a first direction and are capable of engaging with the edges of the engagement holes 123. The engagement of the claws 124 with the edges of the engagement holes 123 prevents the first holder 120A from coming out of the second holder 120B.

[0060] The elastic member 130 is a compression spring. The elastic member 130 is located between the first holder 120A and the second holder 120B. One end of the elastic member 130 in the second direction is in contact with the first holder 120A. The other end of the elastic member 130 in the second direction is in contact with the second holder 120B.

[0061] The elastic member 130 biases the first holder 120A relative to the second holder 120B in a direction away from the second holder 120B in the second direction. In other words, the elastic member 130 biases the first end 121 relative to the second end 122 in a direction away from the second end 122 in the second direction. Furthermore, the elastic member 130 biases the electrical contact surface 111 of the memory 110 relative to the second end 122 in a direction away from the second end 122 in the second direction.

[0062] As shown in Figures 5 and 6, the holder 120 is movable relative to the developing frame 75. More specifically, the developing frame 75 has a boss 75A. The holder 120 has a hole 125. The boss 75A extends in a first direction. More specifically, the boss 75A extends outward in the first direction from one end of the developing frame 75 in the first direction. In this embodiment, the boss 75A is cylindrical. Of the multiple screws 79, screw 79A is fastened to the boss 75A.

[0063] Hole 125 is a hole into which boss 75A can be inserted. Hole 125 penetrates in a first direction. In this embodiment, hole 125 is located in the first holder 120A (see Figure 6). Viewed from the first direction, hole 125 is larger than boss 75A. With boss 75A inserted in hole 125, holder 120 is movable relative to the developing frame 75. More specifically, holder 120 is movable relative to the developing frame 75 in directions perpendicular to the first direction, including a second direction. In the first direction, holder 120 is located between the gear cover 78 and the developing frame 75.

[0064] As shown in Figure 3, with the developing unit 7 mounted on the drum unit 6, the holder 120 is positioned within the width of the drum frame 65 in a first direction. More specifically, the holder 120 is positioned between the first side wall 65A and the second side wall 65B of the drum frame 65 in a first direction. The holder 120 is closer to the first side wall 65A than to the second side wall 65B in a first direction. The holder 120 is positioned between the first side wall 65A and the developing frame 75 in a first direction.

[0065] As shown in Figure 4, the drum frame 65 further has a receiving portion 65E. The receiving portion 65E protrudes from the connecting wall 65C. The receiving portion 65E has a wall shape. The receiving portion 65E is located between the first side wall 65A and the second side wall 65B. In the first direction, the receiving portion 65E is closer to the first side wall 65A than to the second side wall 65B.

[0066] As shown in Figure 8, with the developing unit 7 mounted on the drum unit 6, the receiving portion 65E extends in a direction intersecting the second direction. In this embodiment, with the developing unit 7 mounted on the drum unit 6, the receiving portion 65E extends in a direction perpendicular to the second direction. The receiving portion 65E is contactable by the second end 122 of the holder 120. In this embodiment, with the developing unit 7 mounted on the drum unit 6, the receiving portion 65E is located between the holder 120 and the agitator gear 77E in the second direction.

[0067] As shown in Figure 9, the image forming apparatus 1 further includes a main contact 210. The main contact 210 is located at the bottom of the apparatus body 21. The main contact 210 is made of a conductive metal. The main contact 210 is electrically connected to the control unit of the image forming apparatus 1.

[0068] The main body contact 210 faces upward. Furthermore, the main body contact 210 is inclined with respect to the horizontal plane PL (see dashed line). More specifically, the main body contact 210 is inclined with respect to the horizontal plane PL so as to face the cover axis 22X side of the top cover 22. In this embodiment, the main body contact 210 faces diagonally upward and backward.

[0069] The apparatus body 21 has a guide 220. The guide 220 guides the movement of the process cartridge 5 when it is mounted on the apparatus body 21. In this embodiment, the guide 220 is a groove that is recessed outward in a first direction (left-right direction). The guide 220 includes a first guide 221 and a second guide 222.

[0070] The first guide 221 is engageable with the shaft 61S of the drum unit 6. The first guide 221 engages with the shaft 61S when the process cartridge 5 is mounted on the apparatus body 21 and guides the movement of the shaft 61S. Viewed from a first direction, the first guide 221 extends diagonally upward and forward from the position of the shaft 61S when the process cartridge 5 is mounted on the apparatus body 21. The upper end of the first guide 221 is open upward to allow the shaft 61S to enter.

[0071] The second guide 222 is engageable with the guided boss 65D of the drum unit 6. The second guide 222 engages with the guided boss 65D when the process cartridge 5 is mounted on the device body 21 and guides the movement of the guided boss 65D. Viewed from the first direction, the second guide 222 extends diagonally upward and forward from the position of the guided boss 65D when the process cartridge 5 is mounted on the device body 21. The upper end of the second guide 222 is open upward to allow the guided boss 65D to enter. The second guide 222 is located below the first guide 221.

[0072] The main body of the device 21 includes a first side frame 211, a second side frame 212 (see Figure 2), and a scanner cover 213.

[0073] The first side frame 211 is located at one end of the device body 21 in the first direction. The second side frame 212 is located at the other end of the device body 21 in the first direction. The first side frame 211 and the second side frame 212 face each other, separated from each other, in the first direction.

[0074] The first side frame 211 and the second side frame 212 each have a guide 220 (see also Figure 2). The guide 220 of the first side frame 211 and the guide 220 of the second side frame 212 have a nearly symmetrical structure. The main body contact 210 is located below the guide 220. More specifically, the main body contact 210 is located below the first guide 221. Also, the main body contact 210 is located below the second guide 222. In this embodiment, the main body contact 210 is located below the lower end of the second guide 222.

[0075] The scanner cover 213 is a component that covers the exposure unit 4 from above within the main body 21 of the device. The scanner cover 213 has a plate shape. The scanner cover 213 extends in a first direction so as to connect the first side frame 211 and the second side frame 212. Viewed from the first direction, the scanner cover 213 extends diagonally downward and backward from the opening 21A on the top surface of the main body 21 of the device. The main body contact 210 is located below the scanner cover 213. Also, the main body contact 210 is located behind the scanner cover 213.

[0076] The first side frame 211 further includes a holder guide 230. The holder guide 230 guides the movement of the holder 120 when the process cartridge 5 is mounted on the apparatus body 21. In this embodiment, the holder guide 230 protrudes inward in a first direction, and the holder 120 is contactable on its upper surface. Viewed from the first direction, the holder guide 230 extends diagonally upward and forward to diagonally downward and backward.

[0077] The holder guide 230 is located below the scanner cover 213. Furthermore, the holder guide 230 is located behind the scanner cover 213. The holder guide 230 has a recess 231 at its lower end. The recess 231 has a shape that curves downwards. The main body contact 210 is located within the recess 231.

[0078] As shown in Figure 10, the main body contact 210 is located between the first side frame 211 and the second side frame 212 in the first direction. As a result, the main body contact 210 is located inside the guide 220 in the first direction. The main body contact 210 is closer to the first side frame 211 than to the second side frame 212 in the first direction.

[0079] As shown in Figure 11, with the process cartridge 5 mounted on the main unit 21, the developing roller 71 is positioned below the photosensitive drum 61. Also, with the process cartridge 5 mounted on the main unit 21, the main unit contact 210 is positioned below the developing roller 71. With the process cartridge 5 mounted on the main unit 21, the electrical contact surface 111 is below the photosensitive drum 61 and in contact with the main unit contact 210. Furthermore, with the process cartridge 5 mounted on the main unit 21, the electrical contact surface 111 is below the developing roller 71 and in contact with the main unit contact 210.

[0080] With the process cartridge 5 mounted on the main body 21, the main body contact 210 and the receiving portion 65E of the drum unit 6 face each other in the second direction. With the process cartridge 5 mounted on the main body 21, the receiving portion 65E contacts the second end 122 to restrict the movement of the holder 120. Specifically, the receiving portion 65E contacts the second end 122 to restrict the movement of the holder 120 toward the receiving portion 65E in the second direction. With the process cartridge 5 mounted on the main body 21, the elastic member 130 biases its electrical contact surface 111 toward the main body contact 210.

[0081] Viewed from the first direction, the main contact 210 is located below the straight line LN. The straight line LN is a hypothetical straight line that passes through the contact point CP and the drum shaft 61X when viewed from the first direction. The contact point CP is the contact point between the receiving portion 65E of the drum frame 65 and the second end portion 122 of the holder 120.

[0082] Viewed from the first direction, the photosensitive drum 61 rotates in a rotational direction in which the electrical contact surface 111 approaches the main body contact 210 when a driving force is supplied. In this embodiment, viewed from the other side of the first direction (viewing the image forming apparatus 1 from the right), the photosensitive drum 61 rotates in a counterclockwise direction.

[0083] The image forming apparatus 1 further includes a drum drive gear 240. The photosensitive drum 61 has a drum gear 61G (see Figure 4). The drum gear 61G is located at one end of the photosensitive drum 61 in a first direction. The drum drive gear 240 transmits driving force to the photosensitive drum 61 when the process cartridge 5 is mounted on the apparatus body 21. The drum drive gear 240 meshes with the drum gear 61G when the process cartridge 5 is mounted on the apparatus body 21.

[0084] In this embodiment, as shown in Figure 11, when viewed from the other side of the first direction, the drum drive gear 240 rotates clockwise when a driving force is supplied. As a result, the photosensitive drum 61 rotates counterclockwise. When the photosensitive drum 61 rotates counterclockwise, a force acts on the process cartridge 5 that attempts to rotate the process cartridge 5 counterclockwise around the drum shaft 61X. This force acts as a force that presses the electrical contact surface 111 against the main body contact 210.

[0085] Next, we will explain how to attach the developing unit 7 to the drum unit 6. As shown in Figures 12(a) to (b), when the developing unit 7 is mounted onto the drum unit 6, the holder 120 comes into contact with the receiving portion 65E of the drum frame 65. As shown in Figure 13(a), when the developing unit 7 is further mounted onto the drum unit 6, the second end portion 122 of the holder 120 comes into contact with the receiving portion 65E.

[0086] As shown in Figure 13(b), as the developing unit 7 is further mounted onto the drum unit 6, the holder 120 moves away from the agitator gear 77E in the second direction relative to the developing frame 75. When the developing unit 7 is mounted onto the drum unit 6, the second end portion 122 is in contact with the receiving portion 65E, which restricts the holder 120 from moving toward the agitator gear 77E in the second direction relative to the developing frame 75.

[0087] Next, we will explain how to attach the process cartridge 5 to the main unit 21 of the apparatus. As shown in Figure 14, when the process cartridge 5 is mounted onto the main body 21 of the device along the guide 220, the holder 120 comes into contact with the scanner cover 213.

[0088] As shown in Figure 15, as more process cartridges 5 are mounted onto the main body 21 of the device, the first end 121 of the holder 120 comes into contact with the scanner cover 213. As a result, the first holder 120A of the holder 120 moves toward the second holder 120B, against the biasing force of the elastic member 130.

[0089] As shown in Figure 16, as more process cartridges 5 are mounted onto the device body 21, the first end 121 no longer comes into contact with the scanner cover 213. As a result, the first holder 120A moves away from the second holder 120B due to the biasing force of the elastic member 130. This allows the holder 120 to move over the scanner cover 213.

[0090] Subsequently, as more process cartridges 5 are mounted onto the main body 21 of the apparatus, the first end 121 of the holder 120 comes into contact with the holder guide 230. As a result, the first holder 120A moves again toward the second holder 120B, against the biasing force of the elastic member 130.

[0091] As the process cartridge 5 is further mounted onto the main body 21 of the apparatus, the holder 120 reaches the recess 231. Then, as shown in Figure 17, the first holder 120A moves relative to the second holder 120B in the second direction, away from the second holder 120B, due to the biasing force of the elastic member 130.

[0092] As a result, the electrical contact surface 111 of the memory 110 comes into contact with the main body contact 210. The electrical contact surface 111 is pressed against the main body contact 210 by the biasing force of the elastic member 130. In this embodiment, the process cartridge 5 is mounted on the device body 21 immediately after the electrical contact surface 111 comes into contact with the main body contact 210.

[0093] Next, the effects of the embodiment will be described. Because the drum frame 65 has a receiving portion 65E that restricts the movement of the holder 120, the holder 120 does not need to protrude significantly from the drum frame 65, compared to, for example, the case where the main body of the apparatus 21 has a receiving portion. This allows the holder 120 to be made smaller, thus suppressing an increase in the size of the process cartridge 5.

[0094] Furthermore, with the process cartridge 5 mounted on the main unit 21, the electrical contact surface 111 contacts the main unit contact 210 below the photosensitive drum 61, so that the electrical contact surface 111 can come into contact with the main unit contact 210 at the end of the process of mounting the process cartridge 5 to the main unit 21. This prevents unnecessary friction between the electrical contact surface 111 and the main unit contact 210 during the process of mounting the process cartridge 5 to the main unit 21.

[0095] The developing unit 7 includes an elastic member 130 that biases the electrical contact surface 111 toward the main body contact 210, thereby stabilizing the contact between the electrical contact surface 111 and the main body contact 210.

[0096] The developing roller 71 is positioned below the photosensitive drum 61, and the main body contact 210 is positioned below the developing roller 71. This further suppresses unnecessary friction between the electrical contact surface 111 and the main body contact 210 during the process of mounting the process cartridge 5 into the main body 21 of the device.

[0097] Since the process cartridge 5 can be attached to and detached from the device body 21 through the opening 21A on the top surface of the device body 21, the process cartridge 5 can be installed from above downwards. This further reduces unnecessary friction between the electrical contact surface 111 and the main body contact 210 during the installation of the process cartridge 5 into the device body 21.

[0098] The configuration allows the process cartridge 5 to be installed from top to bottom, and the main body contact 210 faces upward, which further suppresses unnecessary friction between the electrical contact surface 111 and the main body contact 210 during the process of installing the process cartridge 5 into the device body 21.

[0099] The upward-facing main body contact 210 is also tilted relative to the horizontal plane PL so as to face the cover axis 22X side of the top cover 22, making it difficult to touch the main body contact 210 when the top cover 22 is in the open position. Specifically, the main body contact 210 is facing diagonally upward and backward, making it difficult to touch the main body contact 210 when the top cover 22 is in the open position.

[0100] Viewed from the first direction, the main body contact 210 is located below the straight line LN passing through the contact point CP of the receiving portion 65E and the second end portion 122 and the drum shaft 61X, and the photosensitive drum 61 rotates in a rotational direction in which the electrical contact surface 111 approaches the main body contact 210, so that when the photosensitive drum 61 rotates, the electrical contact surface 111 can be pressed against the main body contact 210.

[0101] The main body contact 210 is located inside the guide 220 in the first direction, and the holder 120 is located within the width of the drum frame 65 in the first direction, which further suppresses the increase in size of the process cartridge 5.

[0102] Although embodiments have been described above, the image forming apparatus can be modified as appropriate, as illustrated below.

[0103] In the embodiment, the first holder 120A of the holder 120 had a hole 125, but for example, the second holder may have a hole into which the boss of the developing frame can fit. Also, in the embodiment, the holder 120 was configured as two parts having the first holder 120A and the second holder 120B, but for example, the holder may be configured as three or more parts, or as a single part.

[0104] In this embodiment, the main body contact 210 was inclined with respect to the horizontal plane PL, but for example, the main body contact does not have to be inclined with respect to the horizontal plane.

[0105] In this embodiment, the elastic member 130 was a compression spring (compression coil spring), but for example, the elastic member may be a torsion spring or a leaf spring. Also, the developing unit does not need to be equipped with an elastic member.

[0106] In this embodiment, the developing unit 7 was detachable from the drum unit 6, but for example, the developing unit does not necessarily have to be detachable from the drum unit.

[0107] In this embodiment, the image forming apparatus 1 was a printer, but for example, the image forming apparatus may be a copier or a multifunction device.

[0108] The elements described in the embodiments and modifications may be implemented in any combination. [Explanation of Symbols]

[0109] 1. Image forming apparatus 5 Process Cartridges 6 Drum Units 7. Developing Unit 21 Main unit of the device 61 Photosensitive drum 61X Drum Axis 65 Drum Frames 65E Receiving part 71 Developing roller 71X Developing roller shaft 75 developing frames 110 memory 111 Electrical contact surface 120 Holder 121 First end 122 Second end 210 Main body contacts

Claims

1. The main body of the device, Main unit contacts, A process cartridge that can be attached to the main body of the apparatus, comprising a process cartridge having a developing unit and a drum unit, The aforementioned developing unit is A developing roller that is rotatable with respect to a developing roller shaft extending in the first direction, A developing frame that holds the developing roller, A memory having an electrical contact surface, A holder for holding the memory, comprising a holder that is movable relative to the developing frame, The drum unit is A photosensitive drum that is rotatable with respect to a drum shaft extending in the first direction, The system comprises a drum frame that holds the photosensitive drum, The aforementioned holder is, The first end that holds the memory, It has a second end that is separated from the first end in a second direction intersecting the first direction, The drum frame has a receiving portion that can be contacted by the second end, With the process cartridge installed in the main body of the device, The receiving portion contacts the second end to restrict the movement of the holder. The image forming apparatus is characterized in that the electrical contact surface is located below the photosensitive drum and contacts the main body contacts.

2. The image forming apparatus according to claim 1, further comprising an elastic member that biases the electrical contact surface toward the main body contact when the process cartridge is mounted on the main body of the apparatus.

3. With the process cartridge installed in the main body of the device, The developing roller is located below the photosensitive drum. The image forming apparatus according to claim 1, characterized in that the main body contact is located below the developing roller.

4. The apparatus body has a guide that guides the movement of the process cartridge when the process cartridge is installed. The image forming apparatus according to claim 1, characterized in that the main body contact is located below the guide.

5. The main body of the device has an opening on its upper surface, The image forming apparatus further includes a top cover that is movable between a closed position that closes the opening and an open position that opens the opening. The image forming apparatus according to claim 1, characterized in that the process cartridge is detachable from the main body of the apparatus through the opening when the top cover is in the open position.

6. The image forming apparatus according to claim 5, characterized in that the main body contacts are facing upward.

7. The top cover is rotatable between the closed position and the open position with respect to a cover shaft extending in the first direction. The image forming apparatus according to claim 6, characterized in that the main body contact is inclined with respect to the horizontal plane so as to face the cover shaft side.

8. The image forming apparatus according to claim 1, characterized in that, with the process cartridge mounted on the apparatus body, the main body contact and the receiving portion face each other in the second direction.

9. Viewed from the first direction, The main body contact is located below the line passing through the contact point between the receiving portion and the second end and the drum shaft. The image forming apparatus according to claim 1, characterized in that the photosensitive drum rotates in a rotational direction in which the electrical contact surface approaches the main body contact.

10. The main body contact is located inside the guide in the first direction. The image forming apparatus according to claim 4, characterized in that the holder is located within the width of the drum frame in the first direction.

11. The developing frame has a boss extending in the first direction, The image forming apparatus according to claim 1, characterized in that the holder has a hole into which the boss can be inserted, and is movable relative to the developing frame with the boss inserted into the hole.

12. The aforementioned holder is, A first holder having the aforementioned first end, A second holder having the second end, The image forming apparatus according to claim 2, characterized in that the elastic member is a compression spring located between the first holder and the second holder.

13. The image forming apparatus according to claim 1, characterized in that the developing unit is detachable from the drum unit.

Images