Drum unit and image forming apparatus

Abstract

To provide a drum unit and an image forming apparatus that can accurately locate an electrical contact surface relative to a body electrode.SOLUTION: A drum unit 50 is removably mounted on an apparatus body of an image forming apparatus, and comprises: photoconductor drums 51; a drum frame 53 that holds the photoconductor drums 51; a drum memory 54; an electrical contact surface 55 that is electrically connected to the drum memory 54, and is in contact with the body electrode of the apparatus body when the drum unit 50 is mounted on the apparatus body; and a holder 220 that is movably held on the drum frame 53 and holds the electrical contact surface 55. The holder 220 has: a first groove 280A that is located on one side of the first direction of the electrical contact surface 55, and when the drum unit 50 is mounted on the apparatus body, has the first body projection of the apparatus body fitted thereto; and a second groove 280B that is located on the other side of the first direction of the electrical contact surface 55, and when the drum unit 50 is mounted on the apparatus body, has the second body projection of the apparatus body fitted thereto.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a drum unit and an image forming apparatus. [Background technology]

[0002] Conventionally, a drum unit that is detachable from the main body of an image forming apparatus is known that includes a photosensitive drum and a storage medium having an electrical contact surface (Patent Document 1). The electrical contact surface of the drum unit contacts the main electrode of the main body when the drum unit is attached to the main body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-028345 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, if the electrical contact surface of the drum unit cannot be accurately positioned relative to the main body electrode of the apparatus main body, for example, there is a possibility that the contact between the electrical contact surface and the main body electrode will not be stable.

[0005] Therefore, it is desirable to be able to accurately position the electrical contact surface of the drum unit relative to the main body electrode of the apparatus main body. [Means for solving the problem]

[0006] The drum unit is detachably attached to the main body of the image forming apparatus and includes a first photosensitive drum, a frame, a storage medium, an electrical contact surface, and a holder. The first photosensitive drum is rotatable about a first axis extending in a first direction. The frame holds a first photosensitive drum. The storage medium stores information about the drum unit. The electrical contact surface is electrically connected to the storage medium, and is in electrical contact with a main body electrode of the apparatus main body when the drum unit is attached to the apparatus main body. The holder is movably held by the frame. The holder holds the electrical contact surface. The holder has a first groove and a second groove. The first groove is located on one side of the electrical contact surface in the first direction. A first main body protrusion of the device main body fits into the first groove when the drum unit is attached to the device main body. The second groove is located on the other side of the electrical contact surface in the first direction. A second main body protrusion of the device main body fits into the second groove when the drum unit is attached to the device main body.

[0007] Since the holder has the first groove and the second groove, the electrical contact surface of the drum unit can be accurately positioned with respect to the main body electrode of the apparatus main body.

[0008] The holder may be movable in a first direction relative to the frame.

[0009] The electrical contact surface may be configured to come into contact with the body electrode with the first body projection fitted in the first groove and the second body projection fitted in the second groove.

[0010] The holder may be movable relative to the frame in a second direction transverse to the electrical contact surface.

[0011] The holder may include a first holder, a second holder, and a spring. The first holder holds the electrical contact surface. The second holder holds the first holder so as to be movable in a second direction. The spring is located between the first holder and the second holder and biases the first holder toward the main body electrode with the first body projection fitted in the first groove and the second body projection fitted in the second groove.

[0012] The spring may be elastically deformable between a first state in which the length in the second direction is a first length and a second state in which the length in the second direction is a second length that is shorter than the first length. The spring is in the second state with the first body projection fitted in the first groove and the second body projection fitted in the second groove.

[0013] The holder may have a first protrusion and a second protrusion. The first projection comes into contact with the first main body projection while the drum unit is being mounted to the apparatus main body. The second projection comes into contact with the second main body projection while the drum unit is attached to the apparatus main body. The electrical contact surface moves in a direction away from the body electrode when the first projection contacts the first body projection and the second projection contacts the second body projection.

[0014] When the first protrusion comes into contact with the first main body protrusion and the second protrusion comes into contact with the second main body protrusion, the electrical contact surface moves in a direction away from the main body electrode, thereby preventing unnecessary friction between the electrical contact surface and the main body electrode when the drum unit is attached to the device main body.

[0015] The holder may have a first boss extending in a first direction from the second holder, and the frame may have a first hole into which the first boss fits. When viewed from the first direction, the first hole is larger than the first boss.

[0016] The first hole is larger than the first boss, so that the holder can move relative to the frame in a direction perpendicular to the first direction.

[0017] The holder may be configured to rotate with respect to the electrical contact surface while the electrical contact surface and the main body electrode are in contact with each other while the drum unit is being removed from the main body of the apparatus.

[0018] While the drum unit is being removed from the device main body, the holder rotates relative to the electrical contact surface, allowing the first groove of the holder to be disengaged from the first main body protrusion and the second groove to be disengaged from the second main body protrusion.

[0019] The holder may have a second boss extending in the first direction from the second holder, and the frame may have a second hole into which the second boss fits. When viewed from the first direction, the second hole is larger than the second boss.

[0020] Because the first hole is larger than the first boss and the second hole is larger than the second boss, the holder can be moved relative to the frame in a direction perpendicular to the first direction, while the frame has a second hole into which the second boss fits, restricting rotation of the holder around the first boss.

[0021] The electrical contact surface may be located on one side of the frame in the first direction, the storage medium may be located on the other side of the frame in the first direction, and the drum unit may include a flat cable. The flat cable electrically connects the electrical contact surface and the storage medium.

[0022] The flat cable may include a first portion extending from the holder, a second portion extending from the first portion, and a third portion extending from the second portion. The direction in which the first portion extends and the direction in which the second portion extends are different from each other. The direction in which the second portion extends and the direction in which the third portion extends are different from each other.

[0023] The first portion extends in a direction different from the direction in which the second portion extends, so that the first portion can rotate at the bent portion between the first portion and the second portion. The second portion extends in a direction different from the direction in which the third portion extends, so that the second portion can rotate at the bent portion between the second portion and the third portion. This makes it difficult for force to be applied to the holder from the flat cable, so that displacement of the holder can be suppressed.

[0024] The frame may have a first wall and a second wall. The first wall extends along the second portion. The second wall extends along the third portion.

[0025] The frame has a first wall and a second wall, which makes it possible to guide the flat cable and also to prevent the flat cable from moving significantly.

[0026] The drum unit may further include a second photosensitive drum. The second photosensitive drum is rotatable about a second axis extending in the first direction. The second photosensitive drum is aligned with the first photosensitive drum in a direction perpendicular to the first direction.

[0027] The image forming apparatus includes an apparatus main body to which a drum unit can be detachably attached. The device body has a body electrode, a first body projection, a second body projection, and a contact surface. The contact surface faces the main body electrode in the second direction. The contact surface comes into contact with the second holder when the drum unit is attached to the apparatus main body. The holder spring is in a second state with the electrical contact surface in contact with the body electrode and the second holder in contact with the contact surface.

[0028] When the electrical contact surface is in contact with the main body electrode and the second holder is in contact with the contact surface, the spring is in the second state, so that when the drum unit is attached to the device main body, the spring can reliably bring the electrical contact surface into contact with the main body electrode.

[0029] The device body may have a guide surface. The guide surface guides the second holder to the contact surface while the drum unit is being attached to the main body of the apparatus. The guide surface is inclined with respect to the second direction. The spring of the holder elastically deforms from the first state to the second state while the second holder is guided by the guide surface.

[0030] While the second holder is guided by the guide surface, the spring elastically deforms from the first state, so that the holder can be guided between the contact surface and the main body electrode when the drum unit is attached to the device main body. Effect of the Invention

[0031] The electrical contact surface of the drum unit can be accurately positioned relative to the main body electrodes of the apparatus main body. [Brief description of the drawings]

[0032] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of an image forming apparatus. [Diagram 2] FIG. 2 is a perspective view showing the drum unit. [Diagram 3] 2 is a perspective view showing a first connector, a relay board, and a flat cable. FIG. [Figure 4] FIG. [Diagram 5] 4 is a cross-sectional view showing a state in which the first connector and the main body connector are electrically connected. FIG. [Figure 6] 1A is a perspective view showing a first connector, and FIG. 1B is a cross-sectional view showing the first connector. [Figure 7] 4 is a perspective view showing a first boss, a second boss, a first hole, and a second hole on one side in a first direction. FIG. [Figure 8] 4 is a cross-sectional view showing a first boss, a second boss, a first hole, and a second hole on the other side in the first direction. FIG. [Figure 9] FIG. 2 is a perspective view showing a part of the drum frame and a part of the flat cable. [Figure 10] 4 is a diagram showing a cross section of a part of the drum frame and a first connector, and a part of the flat cable. FIG. [Figure 11] 11 is a cross-sectional view showing a state in which a main body protrusion of the device main body is fitted into a groove of the holder. FIG. [Figure 12] 13A and 13B are diagrams illustrating the operation when the drum unit is attached to the main body of the apparatus. [Figure 13] 13A and 13B are diagrams continuing from FIG. 12, illustrating the operation when the drum unit is attached to the main body of the apparatus. [Figure 14] 13(a) and 13(b), which explain the operation when the drum unit is attached to the main body of the apparatus. [Figure 15]11A to 11C are diagrams illustrating the operation when the drum unit is removed from the main body of the apparatus. [Figure 16] 16A to 16C are diagrams continuing from FIG. 15, illustrating the operation when the drum unit is removed from the main body of the apparatus. [Figure 17] 17A to 17C are diagrams continuing from FIG. 16, illustrating the operation when the drum unit is removed from the main body of the apparatus. [Figure 18] 18A to 18C are diagrams continuing from FIG. 17, illustrating the operation when the drum unit is removed from the main body of the apparatus. [Figure 19] 18(a) to (c), which are continued from FIG. 18, and explain the operation when the drum unit is removed from the main body of the apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Next, an embodiment will be described. 1, the image forming apparatus 1 is a color printer capable of forming a color image on a sheet S such as paper. The image forming apparatus 1 includes a device main body 10, a cover 11, a sheet supply unit 20, and an image forming unit 30.

[0034] In the drawings referred to, the first direction (see FIG. 2), the third direction, the fourth direction, and the fifth direction are indicated by an arrow and indicated by an absence of an arrow.

[0035] The device body 10 has an opening 10A. The cover 11 opens and closes the opening 10A. The cover 11 is movable relative to the device body 10 between a closed position shown by a solid line and an open position shown by a virtual line. Specifically, the cover 11 is rotatable relative to the device body 10 between the closed position and the open position. The closed position is a position where the opening 10A is closed. The open position is a position where the opening 10A is opened. The device main body 10 is equipped with a main body connector 100 .

[0036] The sheet supply unit 20 includes a sheet tray 21 and a sheet supply mechanism 22. The sheet tray 21 stores the sheets S. The sheet supply mechanism 22 includes a pickup roller 23, a separation roller 24, a separation pad 25, a transport roller 26, and a registration roller 27.

[0037] The pickup roller 23 delivers the sheet S from the sheet tray 21 . The separation roller 24 and the separation pad 25 separate the sheets S sent out by the pickup roller 23 into one sheet. The conveying roller 26 and the registration roller 27 convey the sheet S to the image forming unit 30 .

[0038] The image forming section 30 includes an exposure unit 40, a drum unit 50, four developing cartridges 60, a transfer unit 70, and a fixing unit 80. The exposure unit 40 includes a light source, a deflector, a lens, a mirror, etc. The exposure unit 40 emits a light beam as indicated by a dashed line to expose the surface of the photosensitive drum 51.

[0039] The drum unit 50 includes four photosensitive drums 51, four chargers 52, a first connector C1, and four second connectors C2. A toner image is formed on the surface of the photosensitive drum 51 .

[0040] The photosensitive drums 51 include a first photosensitive drum 51Y, a second photosensitive drum 51M, a third photosensitive drum 51C, and a fourth photosensitive drum 51K. The first photosensitive drum 51Y is rotatable about a first axis X1 extending in a first direction. The second photosensitive drum 51M is rotatable about a second axis X2 extending in the first direction. The third photosensitive drum 51C is rotatable about a third axis X3 extending in the first direction. The fourth photosensitive drum 51K is rotatable about a fourth axis X4 extending in the first direction.

[0041] The second photosensitive drum 51M is aligned with the first photosensitive drum 51Y in the third direction. The third photosensitive drum 51C is aligned with the first photosensitive drum 51Y and the second photosensitive drum 51M in the third direction. The fourth photosensitive drum 51K is aligned with the first photosensitive drum 51Y, the second photosensitive drum 51M, and the third photosensitive drum 51C in the third direction.

[0042] Specifically, the four photosensitive drums 51 are arranged in the order of the first photosensitive drum 51Y, the second photosensitive drum 51M, the third photosensitive drum 51C, and the fourth photosensitive drum 51K from one side to the other in the third direction. More specifically, the four photosensitive drums 51 are arranged in the order of the first photosensitive drum 51Y, the second photosensitive drum 51M, the third photosensitive drum 51C, and the fourth photosensitive drum 51K from upstream to downstream in the transport direction of the sheet S.

[0043] The charger 52 charges the surface of the photosensitive drum 51 . The first connector C1 is electrically connected to the main body connector 100 when the drum unit 50 is attached to the apparatus main body 10. The second connector C2 is electrically connected to the first connector C1.

[0044] The third direction is a direction perpendicular to the first direction (see FIG. 2). The fourth direction is a direction perpendicular to the first direction. The fourth direction is a direction intersecting the third direction. In this embodiment, the fourth direction is a direction perpendicular to both the first direction and the third direction. The fourth direction corresponds to the up-down direction of the image forming apparatus 1. One side of the fourth direction corresponds to the upper side of the image forming apparatus 1, and the other side of the fourth direction corresponds to the lower side of the image forming apparatus 1.

[0045] The drum unit 50 is detachable from the device body 10 of the image forming apparatus 1. Specifically, the drum unit 50 is detachable from the device body 10 through the opening 10A when the cover 11 is in the open position shown by the imaginary line.

[0046] In this embodiment, when the drum unit 50 is attached to the device body 10, it moves along the third direction from one side to the other side of the third direction relative to the device body 10, and then moves diagonally toward the other side of the third direction and the other side of the fourth direction. When the drum unit 50 is removed from the device body 10, it moves diagonally toward one side of the third direction and one side of the fourth direction relative to the device body 10, and then moves along the third direction from the other side of the third direction to one side.

[0047] In the following, the direction in which the drum unit 50 moves diagonally downward and rearward when the drum unit 50 is attached to the device body 10 and the direction in which the drum unit 50 moves diagonally upward and frontward when the drum unit 50 is removed from the device body 10 are referred to as the fifth direction. One of the fifth directions is the direction in which the drum unit 50 moves diagonally downward and rearward. The other of the fifth directions is the direction in which the drum unit 50 moves diagonally upward and frontward.

[0048] The developing cartridge 60 contains toner and includes a developing roller 61, a developing connector 62, and a developing memory 63. The developing roller 61 supplies the toner to the photosensitive drum 51 . The developing connector 62 is electrically connected to the second connector C2 when the developing cartridge 60 is attached to the drum unit 50.

[0049] The developing memory 63 is electrically connected to the developing connector 62. The developing memory 63 is, for example, an IC chip. The developing memory 63 stores information about the developing cartridge 60. The information about the developing cartridge 60 is, for example, information about the developing roller 61, information about the life of the developing cartridge 60, etc. The information about the developing roller 61 is, for example, the manufacturing date, manufacturing location, and maximum number of rotations of the developing roller 61 that can be used. The information about the life of the developing cartridge 60 is, for example, the cumulative number of rotations of the developing roller 61, the cumulative number of prints using the developing cartridge 60, etc. The device main body 10 can communicate with the developing memory 63 in a state in which the developing connector 62 and the second connector C2 are electrically connected and the first connector C1 and the main body connector 100 are electrically connected.

[0050] The developing cartridges 60 are detachable from the drum unit 50. The developing cartridges 60 include a first developing cartridge 60Y, a second developing cartridge 60M, a third developing cartridge 60C, and a fourth developing cartridge 60K.

[0051] The first developing cartridge 60Y contains yellow toner. The first developing cartridge 60Y includes a first developing roller 61Y. The first developing roller 61Y supplies yellow toner to the first photosensitive drum 51Y. The second developing cartridge 60M contains magenta toner. The second developing cartridge 60M has a second developing roller 61M. The second developing roller 61M supplies magenta toner to the second photosensitive drum 51M.

[0052] The third developing cartridge 60C contains cyan toner. The third developing cartridge 60C includes a third developing roller 61C. The third developing roller 61C supplies cyan toner to the third photosensitive drum 51C. The fourth developing cartridge 60K contains black toner. The fourth developing cartridge 60K has a fourth developing roller 61K. The fourth developing roller 61K supplies black toner to the fourth photosensitive drum 51K.

[0053] The transfer unit 70 includes a drive roller 71, a driven roller 72, an endless transfer belt 73, and four transfer rollers 74. The transfer belt 73 is stretched over a driving roller 71 and a driven roller 72. The outer surface of the transfer belt 73 contacts the photosensitive drum 51. The transfer roller 74 is disposed on the inner side of the transfer belt 73. The transfer roller 74 and the photosensitive drum 51 sandwich the transfer belt 73 therebetween.

[0054] The fixing unit 80 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 .

[0055] The charger 52 charges the surface of the photosensitive drum 51. Next, the exposure unit 40 emits a light beam onto the charged surface of the photosensitive drum 51. As a result, an electrostatic latent image based on image data is formed on the photosensitive drum 51. Next, the development roller 61 supplies toner to the exposed surface of the photosensitive drum 51. As a result, a toner image is formed on the photosensitive drum 51.

[0056] Thereafter, the photosensitive drum 51 and the transfer roller 74 transport the sheet S supplied from the registration roller 27. As a result, the toner image formed on the photosensitive drum 51 is transferred to the sheet S. Thereafter, the heating roller 81 and the pressure roller 82 transport the sheet S onto which the toner image has been transferred. As a result, the toner image transferred to the sheet S is fixed onto the sheet S. The intermediate discharge rollers 15 and the discharge rollers 16 discharge the sheet S onto which the toner image has been fixed onto the discharge tray 13.

[0057] As shown in FIG. 2, the drum unit 50 further includes a drum frame 53 as a frame, a drum memory 54 as a storage medium, and an electrical contact surface 55 of the first connector C1.

[0058] The drum frame 53 holds the four photosensitive drums 51 (the first photosensitive drum 51Y, the second photosensitive drum 51M, the third photosensitive drum 51C, and the fourth photosensitive drum 51K), the four chargers 52, the first connector C1, and the four second connectors C2. The drum frame 53 has a first frame 53A, a second frame 53B, a third frame 53C, and a fourth frame 53D.

[0059] The first frame 53A is located at one end in the first direction of the drum frame 53. The first frame 53A extends in the third direction. The second frame 53B is located at the other end in the first direction of the drum frame 53. The second frame 53B extends in the third direction. The first frame 53A and the second frame 53B face each other in the first direction.

[0060] The third frame 53C is located at one end in the third direction of the drum frame 53. The third frame 53C extends in the first direction. The third frame 53C connects one end in the third direction of the first frame 53A and one end in the third direction of the second frame 53B.

[0061] The fourth frame 53D is located at the other end of the drum frame 53 in the third direction. The fourth frame 53D extends in the first direction. The fourth frame 53D connects the other end of the first frame 53A in the third direction to the other end of the second frame 53B in the third direction. The third frame 53C and the fourth frame 53D face each other in the third direction.

[0062] The drum memory 54 is located on the other side of the drum frame 53 in the first direction. Specifically, the drum memory 54 is located at the other end of the fourth frame 53D in the first direction. The drum memory 54 stores information about the drum unit 50. The information about the drum unit 50 is, for example, information about the photosensitive drum 51, information about the life of the drum unit 50, etc. The information about the photosensitive drum 51 is, for example, the manufacturing date, manufacturing place, and maximum number of rotations of the photosensitive drum 51 that can be used. The information about the life of the drum unit 50 is, for example, the cumulative number of rotations of the photosensitive drum 51, the cumulative number of printed sheets using the photosensitive drum 51, etc.

[0063] The electrical contact surface 55 is in electrical contact with the main electrode 110 (see FIG. 4) of the main body 10 when the drum unit 50 is attached to the main body 10. The electrical contact surface 55 is located on one side of the drum frame 53 in the first direction. Specifically, the electrical contact surface 55 is located on one end of the fourth frame 53D in the first direction.

[0064] The apparatus main body 10 is capable of communicating with the drum memory 54 when the drum unit 50 is attached to the apparatus main body 10 and the first connector C1 and the main body connector 100 are electrically connected (see FIG. 1).

[0065] 3, the drum unit 50 further includes a flat cable 56. The flat cable 56 electrically connects the electrical contact surface 55 and the drum memory 54. The flat cable 56 is, for example, a flexible flat cable (FFC).

[0066] As shown in FIG. 4, the main body connector 100 of the device main body 10 has a plurality of main body electrodes 110, a first connector frame 120, and a second connector frame . The multiple body electrodes 110 are aligned in a first direction. As an example, the body electrodes 110 are pogo pins.

[0067] The first connector frame 120 holds the body electrode 110. The first connector frame 120 has a body protrusion 140. The body protrusion 140 includes a first body protrusion 140A and a second body protrusion 140B. The first body projection 140A is located on one side of the body electrode 110 in the first direction. The second body projection 140B is located on the other side in the first direction of the body electrode 110. The body electrode 110 is located between the first body projection 140A and the second body projection 140B in the first direction.

[0068] 5, the main body connector 100 opens toward the other side in the fifth direction. This allows the main body connector 100 to receive the first connector C1 that moves from the other side to the one side in the fifth direction when the drum unit 50 is attached to the apparatus main body 10.

[0069] The second connector frame 130 has a contact surface 131 and a guide surface 132 . The contact surface 131 comes into contact with the second holder 240 of the first connector C1 when the drum unit 50 is attached to the apparatus main body 10. The contact surface 131 faces the main body electrode 110 in the second direction.

[0070] The second direction is a direction intersecting with the electrical contact surface 55. In this embodiment, the second direction is a direction perpendicular to the electrical contact surface 55. More specifically, the second direction is a direction perpendicular to the electrical contact surface 55 in a state in which the drum unit 50 is attached to the apparatus main body 10 and the electrical contact surface 55 is in contact with the main body electrode 110.

[0071] The first connector C1 is located between the main body electrode 110 and the contact surface 131 when the drum unit 50 is attached to the apparatus main body 10. The contact surface 131 is perpendicular to the second direction.

[0072] The guide surface 132 guides the second holder 240 of the first connector C1 toward the contact surface 131 while the drum unit 50 is being attached to the apparatus main body 10. The guide surface 132 extends from the contact surface 131. The guide surface 132 is inclined with respect to the second direction. Specifically, the guide surface 132 is inclined such that the position in the second direction becomes farther away from the main electrode 110 as the guide surface 132 moves away from the contact surface 131.

[0073] As shown in FIG. 6, the first connector C1 includes a connector board 210 and a holder 220. The connector board 210 and the holder 220 include a connector substrate 210 and a connector holder 220. As shown in FIG.

[0074] The connector substrate 210 has a plurality of electrodes 211. The plurality of electrodes 211 are arranged in a first direction. The electrodes 211 have a flat plate shape. In this embodiment, the electrical contact surface 55 is a surface of the electrode 211 that contacts the main body electrode 110. In other words, the electrode 211 has an electrical contact surface 55.

[0075] 3, the electrical contact surface 55 is electrically connected to the drum memory 54. Specifically, the drum memory 54 is located on a relay substrate 57. The electrode 211 having the electrical contact surface 55 is electrically connected to the drum memory 54 by the flat cable 56 and the wiring on the relay substrate 57.

[0076] 6, the holder 220 holds the electrical contact surface 55. Specifically, the holder 220 holds a connector substrate 210 having electrodes 211. The holder 220 includes a first holder 230, a second holder 240, and two springs 250.

[0077] The first holder 230 holds the electrical contact surface 55. Specifically, the first holder 230 holds the connector board 210. Second holder 240 holds first holder 230. More specifically, second holder 240 holds first holder 230 so as to be movable in the second direction. Second holder 240 holds first holder 230 so as to be linearly movable in the second direction.

[0078] The spring 250 biases the first holder 230 in the second direction in a direction in which the electrical contact surface 55 moves away from the second holder 240. The spring 250 is located between the first holder 230 and the second holder 240. As an example, the spring 250 is a compression coil spring.

[0079] The spring 250 can be elastically deformed between a first state shown by a virtual line in Fig. 6(b) and a second state shown by a solid line. In the first state, the length of the spring 250 in the second direction is a first length L1. In the second state, the length of the spring 250 in the second direction is a second length L2. The second length L2 is shorter than the first length L1.

[0080] As shown in FIG. 5, the second holder 240 has a holder end surface 241 and an inclined surface 242. The holder end surface 241 comes into contact with the contact surface 131 of the main body connector 100 when the drum unit 50 is attached to the apparatus main body 10. The holder end surface 241 is an end surface of the second holder 240 that is farther from the electrical contact surface 55 in the second direction.

[0081] The inclined surface 242 comes into contact with the guide surface 132 of the main body connector 100 while the drum unit 50 is attached to the apparatus main body 10. The inclined surface 242 extends from the holder end surface 241. The inclined surface 242 is inclined with respect to the second direction. Specifically, the inclined surface 242 is inclined such that the position of the inclined surface 242 in the second direction approaches the electrical contact surface 55 as it moves away from the holder end surface 241.

[0082] The spring 250 biases the first holder 230 toward the main electrode 110 when the drum unit 50 is attached to the apparatus main body 10, the electrical contact surface 55 is in contact with the main electrode 110, and the holder end surface 241 is in contact with the contact surface 131. Specifically, the spring 250 is in the second state when the electrical contact surface 55 is in contact with the main electrode 110 and the holder end surface 241 (second holder 240) is in contact with the contact surface 131. As a result, the electrical contact surface 55 is pressed against the main electrode 110 by the restoring force of the spring 250.

[0083] The first connector C1 is a floating connector. A holder 220 of the first connector C1 is movably held by the drum frame 53. More specifically, the holder 220 is movable in a first direction relative to the drum frame 53. The holder 220 is also movable in a second direction relative to the drum frame 53.

[0084] 7 and 8, the holder 220 has a first boss 260 and a second boss 270. The drum frame 53 has a first hole 531 and a second hole 532. The first boss 260 fits into the first hole 531. The second boss 270 fits into the second hole 532.

[0085] The first boss 260 extends in the first direction from the second holder 240. In particular, the first boss 260 includes a one-side first boss 260A and an other-side first boss 260B. The one-side first boss 260A extends from one side surface of the second holder 240 in the first direction toward one side in the first direction. The other-side first boss 260B extends from the other side surface of the second holder 240 in the first direction toward the other side in the first direction.

[0086] The first boss 260 (260A, 260B) has a cylindrical shape. The first boss 260 is located at an end of the side surface of the second holder 240 in the first direction that is far from the electrical contact surface 55 in the second direction and at one end in the third direction. The first boss 260A on one side and the first boss 260B on the other side have a symmetrical structure in the first direction.

[0087] The second boss 270 extends in the first direction from the second holder 240. In particular, the second boss 270 includes a one-side second boss 270A and an other-side second boss 270B. The one-side second boss 270A extends from one side surface of the second holder 240 in the first direction toward one side in the first direction. The other-side second boss 270B extends from the other side surface of the second holder 240 in the first direction toward the other side in the first direction.

[0088] The second boss 270 (270A, 270B) has a cylindrical shape. The second boss 270 is located at an end of the side surface of the second holder 240 in the first direction that is closer to the electrical contact surface 55 in the second direction and at the other end in the third direction. The one-side second boss 270A and the other-side second boss 270B have a symmetrical structure in the first direction.

[0089] The fourth frame 53D of the drum frame 53 has a first retaining wall 533 and a second retaining wall 534. The first retaining wall 533 and the second retaining wall 534 face each other in the first direction. The first retaining wall 533 and the second retaining wall 534 retain the second holder 240.

[0090] The first retaining wall 533 is located on one side in the first direction of the second holder 240. The second retaining wall 534 is located on the other side in the first direction of the second holder 240. The second holder 240 is located between the first retaining wall 533 and the second retaining wall 534 in the first direction.

[0091] The first hole 531 includes a one-side first hole 531A and an other-side first hole 531B. The one-side first hole 531A is located in the first retaining wall 533. The one-side first hole 531A receives the one-side first boss 260A. The other-side first hole 531B is located in the second retaining wall 534. The other-side first hole 531B receives the other-side first boss 260B. The one-side first hole 531A and the other-side first hole 531B have a symmetrical structure in the first direction.

[0092] The second hole 532 includes a one-side second hole 532A and an other-side second hole 532B. The one-side second hole 532A is located in the first retaining wall 533. The one-side second hole 532A receives the one-side second boss 270A. The other-side second hole 532B is located in the second retaining wall 534. The other-side second hole 532B receives the other-side second boss 270B. The one-side second hole 532A and the other-side second hole 532B have a symmetrical structure in the first direction.

[0093] When viewed from the first direction, first hole 531 is larger than first boss 260. Specifically, the dimension of first hole 531 in the third direction is larger than the dimension of first boss 260 in the third direction. Specifically, the dimension of first hole 531 in the third direction is larger than the diameter of first boss 260. Furthermore, the dimension of first hole 531 in the fourth direction is larger than the dimension of first boss 260 in the fourth direction. Specifically, the dimension of first hole 531 in the fourth direction is larger than the diameter of first boss 260.

[0094] When viewed from the first direction, the second hole 532 is larger than the second boss 270. Specifically, the dimension of the second hole 532 in the third direction is larger than the dimension of the second boss 270 in the third direction. Specifically, the dimension of the second hole 532 in the third direction is larger than the diameter of the second boss 270. Furthermore, the dimension of the second hole 532 in the fourth direction is larger than the dimension of the second boss 270 in the fourth direction. Specifically, the dimension of the second hole 532 in the fourth direction is larger than the diameter of the second boss 270.

[0095] This allows the holder 220 to move relative to the drum frame 53 in directions perpendicular to the first direction, including the second direction.

[0096] Moreover, the distance in the first direction between the first holding wall 533 and the second holding wall 534 is slightly larger than the dimension in the first direction of the second holder 240. This allows the holder 220 to move relative to the drum frame 53 in the first direction.

[0097] As shown in FIGS. 9 and 10, the flat cable 56 includes a first portion 56A, a second portion 56B, a third portion 56C, a fourth portion 56D, and a fifth portion 56E. 10, the first portion 56A extends from the holder 220. Specifically, the first portion 56A extends from an end of the holder 220 that is far from the electrical contact surface 55 in the second direction. In this embodiment, the first portion 56A extends along the second direction.

[0098] The second portion 56B extends from the first portion 56A. More specifically, the second portion 56B extends in a bent manner from the end of the first portion 56A farther from the holder 220. The direction in which the first portion 56A extends and the direction in which the second portion 56B extends are different from each other. The angle θ1 between the first portion 56A and the second portion 56B is preferably 70 to 110°.

[0099] In the present embodiment, the second portion 56B extends along the fifth direction. The angle θ1 between the first portion 56A and the second portion 56B is, for example, 88°.

[0100] The third portion 56C extends from the second portion 56B. More specifically, the third portion 56C extends from an end of the second portion 56B farther from the first portion 56A, and is bent. The direction in which the second portion 56B extends and the direction in which the third portion 56C extends are different from each other. The angle θ2 between the second portion 56B and the third portion 56C is preferably 30 to 70°.

[0101] In the present embodiment, the third portion 56C extends along the third direction. The angle θ2 between the second portion 56B and the third portion 56C is, for example, 52°.

[0102] The fourth portion 56D extends from the third portion 56C. More specifically, the fourth portion 56D extends from an end of the third portion 56C far from the second portion 56B in a bent manner. The direction in which the third portion 56C extends and the direction in which the fourth portion 56D extends are different from each other. The angle θ3 between the third portion 56C and the fourth portion 56D is preferably 70 to 110°.

[0103] In the present embodiment, the fourth portion 56D extends along the fourth direction. The angle θ3 between the third portion 56C and the fourth portion 56D is, for example, 90°.

[0104] The fifth portion 56E extends from the fourth portion 56D. More specifically, the fifth portion 56E extends from an end of the fourth portion 56D far from the third portion 56C in a bent manner. The direction in which the fourth portion 56D extends and the direction in which the fifth portion 56E extends are different from each other. In this embodiment, the fifth portion 56E extends so as to be aligned with the third portion 56C.

[0105] The fourth frame 53D of the drum frame 53 has a first wall 535A, a second wall 535B, a third wall 535C, a fourth wall 535D, and a fifth wall 535E. The first wall 535A extends along the second portion 56B of the flat cable 56. The first wall 535A is located between the holder 220 and the second portion 56B.

[0106] The second wall 535B extends along the third portion 56C of the flat cable 56. Specifically, the second wall 535B extends along the third direction. The second wall 535B is located between the third portion 56C and the fifth portion 56E. The first wall 535A extends from near the center of the second wall 535B in the third direction toward one side of the fourth direction, and then bends and extends toward the other side of the fifth direction.

[0107] The third wall 535C extends along the fifth portion 56E of the flat cable 56. Specifically, the third wall 535C extends along the third direction. The third wall 535C is located on the other side of the second wall 535B in the fourth direction. The fifth portion 56E of the flat cable 56 is located between the second wall 535B and the third wall 535C.

[0108] The fourth wall 535D connects the other end in the third direction of the second wall 535B and the other end in the third direction of the third wall 535C. The fifth wall 535E is located on one side in the fourth direction of the first wall 535A. A through hole 536 is formed between the first wall 535A and the fifth wall 535E.

[0109] The first portion 56A of the flat cable 56 passes through the through hole 536 and enters the fourth frame 53D. The flat cable 56 is bent and extends in one direction in the fifth direction so that the second portion 56B is aligned with the first wall 535A. The flat cable 56 is bent and extends in one direction in the third direction so that the third portion 56C is aligned with the second wall 535B.

[0110] The flat cable 56 is bent so that the fourth portion 56D extends in the other direction in the fourth direction, and is further bent so that the fifth portion 56E extends in the other direction in the third direction along the second wall 535B and the third wall 535C. The third portion 56C, the fourth portion 56D, and the fifth portion 56E of the flat cable 56 are arranged to wrap around the second wall 535B.

[0111] 6(a), the holder 220 has a groove 280. Specifically, the first holder 230 has a groove 280. The groove 280 includes a first groove 280A and a second groove 280B.

[0112] The first groove 280A fits into the first main body protrusion 140A (see FIG. 4) of the apparatus main body 10 in a state in which the drum unit 50 is attached to the apparatus main body 10. The first groove 280A is located on one side of the electrical contact surface 55 in the first direction.

[0113] In a state in which the drum unit 50 is attached to the device body 10, the second main body protrusion 140B (see FIG. 4) of the device body 10 fits into the second groove 280B. The second groove 280B is located on the other side in the first direction of the electrical contact surface 55. The electrical contact surface 55 is located between the first groove 280A and the second groove 280B in the first direction.

[0114] The first groove 280A and the second groove 280B have a symmetrical structure in the first direction. The first body protrusion 140A and the second body protrusion 140B have a symmetrical structure in the first direction.

[0115] 11, main body protrusion 140 (140A, 140B) protrudes in the second direction toward holder 220. Main body protrusion 140 has a first protrusion surface 141, a second protrusion surface 142, and an apex 143. First protrusion surface 141 is located on the other side of main body protrusion 140 in the fifth direction. Second protrusion surface 142 is located on one side of main body protrusion 140 in the fifth direction.

[0116] The first protrusion surface 141 and the second protrusion surface 142 are inclined with respect to the fifth direction. Specifically, the first protrusion surface 141 is inclined so as to approach the apex 143 of the main body protrusion 140 from one side to the other side in the fifth direction. The second protrusion surface 142 is inclined so as to approach the apex 143 from one side to the other side in the fifth direction. An angle θ4 that the second protrusion surface 142 makes with the fifth direction is greater than an angle θ5 that the first protrusion surface 141 makes with the fifth direction.

[0117] The groove 280 (280A, 280B) has a shape that can fit into the main body protrusion 140. The groove 280 has a first groove surface 281 and a second groove surface 282. The first groove surface 281 can come into contact with the first protrusion surface 141 when the main body protrusion 140 is fitted into the groove 280. The second groove surface 282 can come into contact with the second protrusion surface 142 when the main body protrusion 140 is fitted into the groove 280.

[0118] As shown in Figures 11 and 5, the electrical contact surface 55 comes into contact with the main body electrode 110 when the drum unit 50 is attached to the device main body 10, the first main body protrusion 140A is fitted into the first groove 280A, and the second main body protrusion 140B is fitted into the second groove 280B.

[0119] Furthermore, with the first body projection 140A fitted in the first groove 280A and the second body projection 140B fitted in the second groove 280B, the spring 250 biases the first holder 230 towards the body electrode 110. Specifically, with the first body projection 140A fitted in the first groove 280A and the second body projection 140B fitted in the second groove 280B, the spring 250 is in the second state.

[0120] 6(a) and 11, the holder 220 further has a holder protrusion 283. Specifically, the first holder 230 has a holder protrusion 283. The holder protrusion 283 includes a first protrusion 283A and a second protrusion 283B.

[0121] The first protrusion 283A comes into contact with the first protrusion surface 141 of the first main body protrusion 140A while the drum unit 50 is being mounted to the device main body 10. The second protrusion 283B comes into contact with the first protrusion surface 141 of the second main body protrusion 140B while the drum unit 50 is being mounted to the device main body 10. The first protrusion 283A and the second protrusion 283B have a symmetrical structure in the first direction.

[0122] 11, holder protrusions 283 (283A, 283B) protrude in the second direction toward first connector frame 120 of main body connector 100. Holder protrusions 283 are located on one side of groove 280 in the fifth direction. The other surface of holder protrusion 283 in the fifth direction forms second groove surface 282. In other words, the other surface of holder protrusion 283 in the fifth direction forms groove 280.

[0123] 12, while the drum unit 50 is attached to the device main body 10, the first protrusion 283A contacts the first main body protrusion 140A, and the second protrusion 283B contacts the second main body protrusion 140B. When the first protrusion 283A contacts the first main body protrusion 140A and the second protrusion 283B contacts the second main body protrusion 140B, the first holder 230 moves in a direction away from the main body electrode 110 in the second direction. In other words, when the first protrusion 283A contacts the first main body protrusion 140A and the second protrusion 283B contacts the second main body protrusion 140B, the electrical contact surface 55 moves in a direction away from the main body electrode 110 in the second direction.

[0124] Next, the operation of mounting the drum unit 50 to the main body 10 will be described. 1, when the drum unit 50 is attached to the device main body 10, the drum unit 50 shown by the imaginary line is pushed in the other direction in the third direction. Then, the drum unit 50 passes through the opening 10A of the device main body 10 and enters the device main body 10, moves from one side to the other in the third direction, and then moves from the other side to one side in the fifth direction.

[0125] 12, when the drum frame 53 moves from the other side to the one side in the fifth direction, the holder protrusions 283 (283A, 283B) of the first holder 230 come into contact with the first protrusion surface 141 of the main body protrusion 140 (140A, 140B). Also, the inclined surface 242 of the second holder 240 comes into contact with the guide surface 132 of the main body connector 100.

[0126] When the drum frame 53 moves further from the other side to the one side in the fifth direction, the first holder 230 moves in the second direction away from the main electrode 110 due to contact between the holder protrusion 283 and the first protrusion surface 141. Also, the second holder 240 moves in the second direction toward the main electrode 110 due to contact between the inclined surface 242 and the guide surface 132.

[0127] The spring 250 elastically deforms from the first state to the second state while the second holder 240 is guided by the guide surface 132. More specifically, the spring 250 elastically deforms from the first state to the second state, and further elastically deforms from the second state to a third state. The third state is a state in which the length of the spring 250 in the second direction is a third length L3. The third length L3 is shorter than the second length L2 (see FIG. 14).

[0128] 13, when the drum frame 53 moves further from the other side to the one side in the fifth direction, the holder protrusion 283 of the first holder 230 passes through the apex 143 of the main body protrusion 140, and the second groove surface 282 comes into contact with the second protrusion surface 142. Also, the holder end surface 241 of the second holder 240 comes into contact with the contact surface 131 of the main body connector 100.

[0129] When the drum frame 53 moves further from the other side to the one side in the fifth direction, the length of the spring 250 in the second direction gradually increases from the third state to the second state. As a result, the first holder 230 moves in the second direction toward the main electrode 110. Then, the electrical contact surface 55 comes into contact with the main electrode 110.

[0130] The electrical contact surface 55 contacts the body electrode 110 along the second direction. In this embodiment, the body electrode 110 is a pogo pin, so in this embodiment, the electrical contact surface 55 can contact the plunger of the pogo pin along the movement direction of the plunger.

[0131] When the cover 11 is moved from the open position shown in phantom lines in Fig. 1 to the closed position shown in solid lines in the state shown in Fig. 13, the drum frame 53 moves from one side to the other in the third direction as shown in Fig. 14. At this time, the main body protrusion 140 of the main body connector 100 fits into the groove 280 of the first holder 230. More specifically, the first main body protrusion 140A fits into the first groove 280A, and the second main body protrusion 140B fits into the second groove 280B.

[0132] When the drum unit 50 is attached to the apparatus main body 10 and the cover 11 is closed, the spring 250 is in the second state. The electrical contact surface 55 is pressed against the main body electrode 110 by the restoring force of the spring 250 in the second state.

[0133] Next, the operation of removing the drum unit 50 from the main body 10 will be described. When the drum unit 50 is removed from the apparatus main body 10, the cover 11 is moved from the closed position shown by the solid line in Fig. 1 to the open position shown by the imaginary line. At this time, the drum frame 53 moves from the position shown in Fig. 15 to the position shown in Fig. 16 relative to the first connector C1 from the other side to the one side in the third direction.

[0134] Thereafter, when the drum unit 50 is pulled in one direction in the third direction, the drum frame 53 first moves from one side to the other side in the fifth direction, as shown in Fig. 17. At this time, one edge of the first hole 531 in the fifth direction abuts against the first boss 260, and the first boss 260 is pushed in the other direction in the fifth direction. As a result, as shown in Figs. 17 and 18, the holder 220 rotates clockwise in the drawings with respect to the electrical contact surface 55 with the main electrode 110 in contact with each other.

[0135] When the drum frame 53 moves further from one side to the other side in the fifth direction, the holder 220 rotates further. As a result, the grooves 280 (280A, 280B) of the holder 220 come off the main body protrusions 140 (140A, 140B) as shown in FIG. 19. This allows the drum frame 53 to move further from one side to the other side in the fifth direction. As the grooves 280 come off the main body protrusions 140, the electrical contact surface 55 moves away from the main body electrode 110.

[0136] 1, the drum unit 50 moves from the other side to the one side in the third direction and is removed from the apparatus main body 10. This makes it possible to replace the developing cartridge 60, replace the drum unit 50 itself, etc.

[0137] Next, the effects of the embodiment will be described. The holder 220 has a first groove 280A into which the first main body protrusion 140A fits and a second groove 280B into which the second main body protrusion 140B fits when the drum unit 50 is attached to the device body 10. This allows the holder 220 to be positioned with high precision relative to the device body 10. This allows the electrical contact surface 55 of the drum unit 50 to be positioned with high precision relative to the main body electrode 110 of the device body 10.

[0138] 5, the spring 250 of the holder 220 is in the second state when the drum unit 50 is attached to the apparatus body 10, the electrical contact surface 55 is in contact with the main body electrode 110, and the second holder 240 is in contact with the contact surface 131. This allows the electrical contact surface 55 to be reliably brought into contact with the main body electrode 110 by the biasing force (restoring force) of the spring 250 when the drum unit 50 is attached to the apparatus body 10.

[0139] As shown in FIG. 8, the first hole 531 of the drum frame 53 is larger than the first boss 260 of the holder 220, so that the holder 220 can move relative to the drum frame 53 in a direction perpendicular to the first direction.

[0140] Furthermore, the drum frame 53 has a second hole 532 into which the second boss 270 of the holder 220 fits, the second hole 532 being larger than the second boss 270. This allows the holder 220 to move relative to the drum frame 53 in a direction perpendicular to the first direction, while restricting rotation of the holder 220 around the first boss 260.

[0141] 10, the extending direction of the first portion 56A of the flat cable 56 is different from the extending direction of the second portion 56B, so that the first portion 56A can be rotated at the bent portion between the first portion 56A and the second portion 56B. Also, the extending direction of the second portion 56B is different from the extending direction of the third portion 56C, so that the second portion 56B can be rotated at the bent portion between the second portion 56B and the third portion 56C.

[0142] Furthermore, since the extending direction of the third portion 56C and the extending direction of the fourth portion 56D are different from each other, the third portion 56C can be rotated at the bending portion between the third portion 56C and the fourth portion 56D. As a result, force is less likely to be applied from the flat cable 56 to the holder 220, and therefore, displacement of the holder 220 can be suppressed.

[0143] The drum frame 53 has a first wall 535A extending along the second portion 56B and a second wall 535B extending along the third portion 56C. This allows the flat cable 56 to be guided by the first wall 535A and the third portion 56C. In addition, the first wall 535A and the third portion 56C can restrict the flat cable 56 from moving significantly.

[0144] 12, when the drum unit 50 is being attached to the apparatus body 10, if the first protrusion 283A contacts the first body protrusion 140A and the second protrusion 283B contacts the second body protrusion 140B, the electrical contact surface 55 moves in the second direction away from the body electrode 110. This makes it possible to prevent the electrical contact surface 55 and the body electrode 110 from rubbing against each other more than necessary when the drum unit 50 is being attached to the apparatus body 10.

[0145] The spring 250 elastically deforms from the first state to the third state via the second state while the second holder 240 is guided by the guide surface 132. This allows the holder 220 to be guided between the contact surface 131 and the main body electrode 110 when the drum unit 50 is attached to the apparatus main body 10.

[0146] 16 to 18, while the drum unit 50 is being removed from the apparatus main body 10, the holder 220 rotates with respect to the electrical contact surface 55 with the main body electrode 110 in contact with each other. By rotating the holder 220, as shown in Fig. 19, the first groove 280A of the holder 220 can be disengaged from the first main body protrusion 140A, and the second groove 280B can be disengaged from the second main body protrusion 140B.

[0147] Although the embodiment has been described above, the drum unit and the image forming apparatus can be modified as appropriate as exemplified below.

[0148] In the above embodiment, the holder 220 has the second boss 270, and the drum frame 53 has the second hole 532, but for example, the second boss and the second hole may not be provided. Even in this case, it is preferable that the holder is held so that the rotation around the first boss is restricted.

[0149] In the above embodiment, the spring 250 is a compression coil spring. However, for example, the spring may be a wire spring, a leaf spring, or the like.

[0150] In the above embodiment, the holder 220 is movable in the first direction and the second direction relative to the drum frame 53, but for example, the holder may be movable only in the first direction relative to the frame. Also, the holder may be movable only in the second direction relative to the frame.

[0151] In the above embodiment, the first portion 56A of the flat cable 56 extends in a direction different from the direction in which the third portion 56C extends, but for example, the first portion may extend in a direction different from the direction in which the third portion extends. Similarly, in the above embodiment, the second portion 56B of the flat cable 56 extends in a direction different from the direction in which the fourth portion 56D extends, but for example, the second portion may extend in a direction different from the direction in which the fourth portion extends.

[0152] In the above embodiment, the drum memory 54 as a storage medium and the electrical contact surface 55 are electrically connected by the flat cable 56, but for example, the storage medium and the electrical contact surface may be located on the same substrate and electrically connected by wiring on the substrate. The drum unit may not have a flat cable. The frame may not have a first wall and a second wall.

[0153] In the above embodiment, the drum unit 50 is configured to include multiple photosensitive drums 51, but for example, the drum unit may be configured to include only one photosensitive drum. In other words, the image forming apparatus may not be a color printer, but a monochrome printer capable of forming only monochrome images. Also, the image forming apparatus may not be a printer, but may be, for example, a copier, a multifunction machine, etc.

[0154] The elements described in the above embodiment and modified examples may be implemented in any combination. [Explanation of symbols]

[0155] 1. Image forming device 10. Device body 50 Drum Unit 51Y First photosensitive drum 53 Drum Frame (Frame) 54 Drum memory (storage medium) 55 Electrical Contact Surface 110 Body electrode 140A First body protrusion 140B 2nd body protrusion 220 Holder 280A 1st groove 280B 2nd groove X1 1st axis

Claims

1. A drum unit that is detachable from a main body of an image forming apparatus, a first photosensitive drum rotatable about a first axis extending in a first direction; a frame for holding the first photosensitive drum; A storage medium that stores information about the drum unit; an electrical contact surface electrically connected to the storage medium, the electrical contact surface being in electrical contact with a main body electrode of the apparatus main body when the drum unit is attached to the apparatus main body; a holder that is movably held on the frame and that holds the electrical contact surface; The holder includes: a first groove located on one side of the electrical contact surface in the first direction, into which a first main body protrusion of the device main body is fitted when the drum unit is attached to the device main body; a second groove located on the other side of the electrical contact surface in the first direction, into which a second main body protrusion of the device main body fits when the drum unit is attached to the device main body.

2. 2. The drum unit according to claim 1, wherein the holder is movable in the first direction relative to the frame.

3. 2. The drum unit according to claim 1, wherein the electrical contact surface contacts the main body electrode when the first main body projection is fitted in the first groove and the second main body projection is fitted in the second groove.

4. 2. The drum unit according to claim 1, wherein the holder is movable relative to the frame in a second direction intersecting the electrical contact surface.

5. The holder includes: a first holder for holding the electrical contact surface; a second holder that holds the first holder movably in the second direction; The drum unit according to claim 4, further comprising: a spring positioned between the first holder and the second holder, the spring urging the first holder toward the main electrode when the first main body protrusion is fitted into the first groove and the second main body protrusion is fitted into the second groove.

6. the spring is elastically deformable between a first state in which the length in the second direction is a first length and a second state in which the length in the second direction is a second length that is shorter than the first length; 6. The drum unit according to claim 5, wherein the spring is in the second state when the first body protrusion is fitted in the first groove and the second body protrusion is fitted in the second groove.

7. The holder includes: a first protrusion that contacts the first main body protrusion while the drum unit is being mounted to the apparatus main body; a second protrusion that contacts the second main body protrusion while the drum unit is being mounted to the apparatus main body; 2. The drum unit according to claim 1, wherein the electrical contact surface moves in a direction away from the body electrode when the first protrusion contacts the first body protrusion and the second protrusion contacts the second body protrusion.

8. the holder has a first boss extending in the first direction from the second holder, the frame has a first hole into which the first boss is inserted; The drum unit according to claim 5 , wherein the first hole is larger than the first boss when viewed from the first direction.

9. 6. The drum unit according to claim 5, wherein the holder rotates relative to the electrical contact surface with the electrical contact surface in contact with the main body electrode while the drum unit is being removed from the main body.

10. the holder has a second boss extending from the second holder in the first direction, the frame has a second hole into which the second boss is inserted; 9. The drum unit according to claim 8, wherein the second hole is larger than the second boss when viewed from the first direction.

11. the electrical contact surface is located on one side of the frame in the first direction; the storage medium is located on the other side of the frame in the first direction; 2. The drum unit according to claim 1, further comprising a flat cable electrically connecting the electrical contact surface and the storage medium.

12. The flat cable is a first portion extending from the holder; a second portion extending from the first portion; a third portion extending from the second portion, The direction in which the first portion extends and the direction in which the second portion extends are different from each other, The drum unit according to claim 11, wherein a direction in which the second portion extends and a direction in which the third portion extends are different from each other.

13. The frame is a first wall extending along the second portion; 13. The drum unit according to claim 12, further comprising a second wall extending along said third portion.

14. 2. The drum unit according to claim 1, further comprising a second photosensitive drum rotatable about a second axis extending in the first direction, the second photosensitive drum being aligned with the first photosensitive drum in a direction perpendicular to the first direction.

15. 7. An image forming apparatus including the main body to which the drum unit according to claim 6 is detachably attached, The device body includes: The body electrode; The first main body projection; The second main body projection; a contact surface facing the main body electrode in the second direction, the contact surface coming into contact with the second holder when the drum unit is attached to the apparatus main body, The image forming apparatus according to claim 1, wherein the spring is in the second state when the electrical contact surface is in contact with the main body electrode and the second holder is in contact with the contact surface.

16. the device main body has a guide surface that guides the second holder to the contact surface while the drum unit is being attached to the device main body, the guide surface being inclined with respect to the second direction; 16. The image forming apparatus according to claim 15, wherein the spring elastically deforms from the first state to the second state while the second holder is guided by the guide surface.

Images