drum cartridge

Abstract

To provide a technique for suppressing friction of an electrical contact surface, in a drum cartridge comprising the electrical contact surface.SOLUTION: A drum cartridge 2 comprises a drum frame 50, a photoreceptor drum 40, a memory 70 and a coil spring 90. An image developing cartridge 1 can be fitted to the drum frame 50. The photoreceptor drum 40 can rotate about an axis extending in a first direction. The memory 70 has an electrical contact surface 71. The coil spring 90 is an elastic member positioned between the electrical contact surface 71 and the drum frame 50. The coil spring 90 can be extended and contracted between a first state, and a second state which is shorter than the first state in a second direction crossing the electrical contact surface. Therefore, the electrical contact surface 71 can move in the second direction relative to the drum frame 50. Accordingly, friction of the electrical contact surface 71 can be suppressed when the drum cartridge 2 is fitted to an image forming apparatus.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] Electrophotographic image forming apparatuses such as laser printers and LED printers have been known in the past. A conventional image forming apparatus is described, for example, in Patent Document 1. The image forming apparatus in Patent Document 1 has a developer cartridge and a drum cartridge. The developer cartridge is attached to the drum cartridge. The drum cartridge with the developer cartridge attached is then attached to the image forming apparatus. The developer cartridge in Patent Document 1 also has an IC chip. The IC chip stores various information related to the developer cartridge. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-189740 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for IC chips to be installed not only in developer cartridges but also in drum cartridges. However, when an IC chip is installed in a drum cartridge, the electrical contact surface of the IC chip on the drum cartridge must be in contact with the electrical contacts of the image forming device. When this happens, the pressure generated between the electrical contacts and the electrical contact surface causes friction on the electrical contact surface.

[0005] An object of the present disclosure is to provide a technology capable of suppressing friction on an electrical contact surface in a drum cartridge having the electrical contact surface. [Means for solving the problem]

[0006] The first disclosure of the present application is a drum cartridge comprising: a drum frame onto which a developing cartridge can be attached; a photosensitive drum rotatable about an axis extending in a first direction; a memory having an electrical contact surface; and an elastic member positioned between the electrical contact surface and the drum frame, the elastic member being expandable and contractible between a first state and a second state that is shorter than the first state in a second direction intersecting the electrical contact surface, and the distance in the second direction between the drum frame and the electrical contact surface when the elastic member is in the second state is shorter than the distance in the second direction between the drum frame and the electrical contact surface when the elastic member is in the first state.

[0007] A second disclosure of the present application is the drum cartridge of the first disclosure, characterized in that the memory stores the number of times the developing cartridge can be replaced with respect to the drum frame.

[0008] The third disclosure of the present application is a drum cartridge as described in the first or second disclosure, characterized in that the developing cartridge does not have a memory and comprises a first gear rotatable about an axis extending in the first direction, the first gear having a first engagement portion on a portion of its outer periphery, and a second gear rotatable about an axis extending in the first direction, the second gear having a second engagement portion that engages with the first engagement portion.

[0009] A fourth disclosure of the present application is the drum cartridge of the third disclosure, characterized in that the first engagement portion is a plurality of gear teeth along a portion of the outer periphery of the first gear.

[0010] The fifth disclosure of the present application is a drum cartridge according to any one of the first to fourth disclosures, characterized in that the memory stores at least one of the amount of developer contained in the developer cartridge, the dot count that can be printed using the developer, and the number of pages that can be printed using the developer.

[0011] The sixth disclosure of the present application is a drum cartridge described in any one of the first to fifth disclosures, characterized in that the electrical contact surface is located on the outer surface of the drum frame when the developing cartridge is attached to the drum frame.

[0012] The seventh disclosure of the present application is a drum cartridge according to any one of the first to sixth disclosures, further comprising a holder that holds the electrical contact surface, wherein one of the drum frame and the holder has a claw, and the other of the drum frame and the holder has a hole into which the claw fits, and the size of the hole in the second direction is larger than the size of the claw in the second direction.

[0013] An eighth disclosure of the present application is the drum cartridge according to any one of the first to seventh disclosures, wherein the elastic member is a coil spring.

[0014] The ninth disclosure of the present application is a drum cartridge according to any one of the first to eighth disclosures, characterized in that the photosensitive drum is located at one end of the drum frame in a third direction that intersects with the first direction. [Effects of the Invention]

[0015] According to the first to ninth disclosures of the present application, the electrical contact surface is movable in the second direction relative to the drum frame, thereby suppressing friction of the electrical contact surface.

[0016] Furthermore, according to the second disclosure of the present application, the control unit of the image forming apparatus can manage the number of times the developing cartridge has been replaced by reading the number of times the developing cartridge has been replaced from the memory of the drum cartridge.

[0017] Furthermore, according to the third disclosure of the present application, the control unit of the image forming apparatus can detect whether the developing cartridge is new or not by detecting the rotation of the first gear.

[0018] Furthermore, according to the fifth disclosure of the present application, the control unit of the image forming device can read the amount of developer contained in the developer cartridge, the dot count that can be printed using the developer, or the number of pages that can be printed using the developer from the memory of the drum cartridge, and notify the user when it is time to replace the developer cartridge.

[0019] Furthermore, according to the seventh disclosure of the present application, the movement of the holder in the second direction is restricted, thereby preventing the holder from falling off the drum frame. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a conceptual diagram of an image forming apparatus. [Figure 2] FIG. 2 is a perspective view of a developing cartridge and a drum cartridge. [Figure 3] FIG. 2 is a perspective view of the drum cartridge with the developing cartridge attached thereto. [Figure 4] FIG. 2 is a view of the drum cartridge with the developer cartridge attached, viewed from one side in the first direction. [Figure 5] FIG. 2 is a plan view of a first gear and a second gear included in the gear unit. [Figure 6] FIG. 2 is an exploded perspective view of a memory, a holder, a coil spring, and a drum frame. [Figure 7] FIG. 2 is a cross-sectional view of a memory, a holder, a coil spring, and a drum frame. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, preferred embodiments of the present disclosure will be described with reference to the drawings.

[0022] In the following description, the direction in which the rotation axis of the photosensitive drum extends will be referred to as the "first direction." The direction intersecting the electrical contact surface will be referred to as the "second direction." The direction in which the end of the drum frame where the photosensitive drum is located is aligned with the other end will be referred to as the "third direction." The first and second directions intersect (preferably perpendicular to) each other. The second and third directions intersect (preferably perpendicular to) each other. The third direction and the first direction intersect (preferably perpendicular to) each other.

[0023] <1. Configuration of image forming device> FIG. 1 is a conceptual diagram of an image forming apparatus 900. This image forming apparatus 900 is an electrophotographic printer. Examples of the image forming apparatus 900 include a laser printer and an LED printer. As shown in FIG. 1, the image forming apparatus 900 has a main body frame 910, a control unit 920, four developing cartridges 1, and four drum cartridges 2.

[0024] The main body frame 910 has four slots 911. The four slots 911 are arranged at intervals in the second direction. One developer cartridge 1 is attached to one drum cartridge 2. One drum cartridge 2 with one developer cartridge 1 attached is attached to one slot 911. Therefore, four sets of one drum cartridge 2 with one developer cartridge 1 attached can be attached to the main body frame 910.

[0025] The four developer cartridges 1 contain developers of different colors (e.g., cyan, magenta, yellow, and black). The image forming apparatus 900 forms an image on the printing surface of printing paper using the developers (e.g., toner) supplied from the developer cartridges 1. However, the number of drum cartridges 2 that can be attached to the main body frame 910 may be one to three, or may be five or more.

[0026] The control unit 920 is configured with, for example, a circuit board. The control unit 920 has a processor such as a CPU and various memories. The control unit 920 executes various processes in the image forming apparatus 900 by the processor operating in accordance with a program.

[0027] Each of the four drum cartridges 2 has a memory 70. The memory 70 is a storage medium from which information can be read and written. When a drum cartridge 2 is attached to a slot 911 of a main body frame 910, the memory 70 and a control unit 920 are electrically connected.

[0028] <2. About the developing cartridge> Fig. 2 is a perspective view of the developer cartridge 1 and the drum cartridge 2. Fig. 3 is a perspective view of the drum cartridge 2 with the developer cartridge 1 attached. Fig. 4 is a view of the drum cartridge 2 with the developer cartridge 1 attached, viewed from one side in the first direction. As shown in Figs. 2 and 3, the developer cartridge 1 has a casing 10, a development roller 20, and a gear portion 30.

[0029] The casing 10 is a housing capable of containing a developer. The casing 10 has a first outer surface 11 and a second outer surface 12. The first outer surface 11 and the second outer surface 12 are spaced apart from each other in a first direction. The casing 10 extends in the first direction between the first outer surface 11 and the second outer surface 12. The gear portion 30 is located on the first outer surface 11. A storage chamber 13 is provided inside the casing 10. The developer is stored in the storage chamber 13. The casing 10 also has an opening 14. The opening 14 is located at one end of the casing 10 in a third direction. The external space of the casing 10 and the storage chamber 13 are in communication via the opening 14.

[0030] The developing roller 20 is a roller that can rotate about a rotation axis that extends in the first direction. The developing roller 20 is located in the opening 14 of the casing 10. That is, the developing roller 20 is located at one end of the casing 10 in the third direction. The developing roller 20 has a roller body and a roller shaft. The roller body is a cylindrical member that extends in the first direction. The roller body is made of, for example, elastic rubber. The roller shaft is a cylindrical member that penetrates the roller body in the first direction. The roller shaft is made of, for example, metal or conductive resin.

[0031] The roller body is fixed to the roller shaft. One end of the roller shaft in the first direction is fixed to a developing roller gear 31 included in the gear unit 30. Therefore, when the developing roller gear 31 rotates, the roller shaft also rotates, and the roller body rotates together with the roller shaft.

[0032] The roller shaft does not have to penetrate the roller body in the first direction. For example, the roller shaft may extend in the first direction from both ends of the roller body in the first direction.

[0033] The developer cartridge 1 also has a supply roller (not shown). The supply roller is located between the developer roller 20 and the storage chamber 13. The supply roller is rotatable about a rotation axis extending in the first direction. When the developer cartridge 1 receives a driving force, developer is supplied from the storage chamber 13 in the casing 10 to the outer circumferential surface of the developer roller 20 via the supply roller. At that time, the developer is frictionally charged between the supply roller and the developer roller 20. Meanwhile, a bias voltage is applied to the roller shaft of the developer roller 20. Therefore, the developer is attracted to the outer circumferential surface of the developer roller 20 due to the electrostatic force between the roller shaft and the developer.

[0034] The developer cartridge 1 also has a layer thickness regulating blade 21. The layer thickness regulating blade 21 shapes the developer supplied to the outer peripheral surface of the development roller 20 to a uniform thickness. The developer on the outer peripheral surface of the development roller 20 is then supplied to a photosensitive drum 40 (described later) of the drum cartridge 2. At this time, the developer moves from the development roller 20 to the photosensitive drum 40 in accordance with the electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 40. As a result, the electrostatic latent image is visualized on the outer peripheral surface of the photosensitive drum 40.

[0035] The gear unit 30 is located on the first outer surface 11 of the casing 10. The gear unit 30 has multiple gears including the above-mentioned developing roller gear 31, a toner coupling 32, and a gear cover 33. The gear cover 33 is fixed to the first outer surface 11 of the casing 10, for example, by screws. At least some of the multiple gears are located between the first outer surface 11 and the gear cover 33. The toner coupling 32 is exposed from the gear cover 33. When the drum cartridge 2 with the developing cartridge 1 installed is installed in the main body frame 910 of the image forming apparatus 900, the toner drive shaft of the image forming apparatus 900 is connected to the toner coupling 32. Then, rotation of the toner drive shaft is transmitted to the multiple gears including the developing roller gear 31 via the toner coupling 32.

[0036] The gears included in the gear unit 30 may transmit a rotational force by meshing of teeth, or may transmit a rotational force by friction.

[0037] FIG. 5 is a plan view of the first gear 34 and the second gear 35 included in the gear unit 30. The first gear 34 is a gear for transmitting information about the developer cartridge 1 to the image forming apparatus 900. The information about the developer cartridge 1 includes information about whether the developer cartridge 1 is a new (unused) developer cartridge or a used developer cartridge. The information about the developer cartridge 1 also includes specifications of the developer cartridge 1. The specifications of the developer cartridge 1 include yield information that indicates the amount of developer in the developer cartridge 1 or the number of pages that can be printed using the developer.

[0038] The first gear 34 is rotatable about a rotation axis extending in the first direction. The first gear 34 has a plurality of gear teeth 341 (first engagement portion) on a portion of its outer periphery. However, the first gear 34 does not have gear teeth 341 on other portions of its outer periphery. The first gear 34 also has a detection protrusion 342. The detection protrusion 342 protrudes from one surface of the first gear 34 in the first direction toward one side in the first direction. The detection protrusion 342 also extends in an arc shape centered on the rotation axis of the first gear 34.

[0039] The second gear 35 is a gear that can mesh with the first gear 34. The second gear 35 is rotatable about a rotation axis that extends in the first direction. The second gear 35 has gear teeth 351 (second engagement portion) around the entire circumference of its outer periphery. When the developing cartridge 1 is new, the gear teeth 341 of the first gear 34 and the gear teeth 351 of the second gear 35 are engaged with each other.

[0040] When the drum cartridge 2 with a new developer cartridge 1 installed is mounted on the main body frame 910 of the image forming apparatus 900, the toner coupling 32 receives a driving force from the toner drive shaft of the image forming apparatus 900. The driving force transmitted from the toner coupling 32 then rotates the second gear 35. The first gear 34 then rotates together with the second gear 35. However, the first gear 34 has gear teeth 341 only on a portion of its outer periphery. Therefore, when the first gear 34 rotates by a predetermined angle, the first gear 34 and the second gear 35 disengage from each other, and the rotation of the first gear 34 stops.

[0041] In this way, in a developer cartridge 1 that has been used once in the image forming apparatus 900, the meshing between the first gear 34 and the second gear 35 is disengaged. Therefore, when a developer cartridge 1 that has been used once is removed from the main body frame 910 and then reattached to the main body frame 910, the rotation of the second gear 35 is not transmitted to the first gear 34. Therefore, the first gear 34 does not rotate.

[0042] The image forming apparatus 900 also has a lever 930 and an optical sensor 940. The lever 930 is capable of coming into contact with the detection protrusion 342 of the first gear 34. The lever 930 is rotatable about a rotation axis extending in the first direction between a first position (position indicated by a solid line in FIG. 5) and a second position (position indicated by a two-dot chain line in FIG. 5) that is farther away from the rotation axis of the first gear 34 than the first position.

[0043] The optical sensor 940 detects the displacement of the lever 930 and transmits a detection signal to the control unit 920. For example, a sensor unit having a light-emitting unit and a light-receiving unit is used as the optical sensor 940. When the lever 930 is in the first position, light from the light-emitting unit is incident on the light-receiving unit without being blocked by the lever 930. On the other hand, when the lever 930 is in the second position, the light from the light-emitting unit is blocked by the lever 930. Therefore, the light from the light-emitting unit does not enter the light-receiving unit. In this way, the optical sensor 940 can determine whether the lever 930 is in the first position or the second position based on the presence or absence of light entering the light-receiving unit.

[0044] The control unit 920 detects whether the developing cartridge 1 attached to the image forming apparatus 1 is new or not based on the detection signal obtained from the optical sensor 940. The control unit 920 also detects the specifications of the developing cartridge 1 attached to the image forming apparatus 1 based on the waveform of the detection signal.

[0045] <3. About the drum cartridge> As shown in FIGS. 2 to 4, the drum cartridge 2 includes a photosensitive drum 40, a drum frame 50, a drum coupling 60, a memory 70, a holder 80, and a coil spring 90.

[0046] The photosensitive drum 40 is a drum that can rotate about a rotation axis that extends in a first direction. The photosensitive drum 40 has a cylindrical outer peripheral surface that extends in the first direction. The outer peripheral surface of the photosensitive drum 40 is covered with a photosensitive material. When the developer cartridge 1 is installed in the drum cartridge 2, the outer peripheral surface of the developing roller 20 of the developer cartridge 1 comes into contact with the outer peripheral surface of the photosensitive drum 40.

[0047] The drum frame 50 has a first side plate 51 and a second side plate 52 located on the other side of the first side plate 51 in the first direction. The photosensitive drum 40 is located at one end of the drum frame 50 in the third direction. More specifically, the photosensitive drum 40 is located between one end of the first side plate 51 in the third direction and one end of the second side plate 52 in the third direction. The photosensitive drum 40 is rotatably supported by the first side plate 51 and the second side plate 52.

[0048] The drum frame 50 can accommodate the developer cartridge 1. Specifically, the drum frame 50 has a recess 53 into which the developer cartridge 1 is attached. The recess 53 is located between the first side plate 51 and the second side plate 52 and on the other side of the photosensitive drum 40 in the third direction.

[0049] The drum coupling 60 is a member that can rotate together with the photosensitive drum 40. The drum coupling 60 is located on the outer surface of one side of the drum frame 50 in the first direction. More specifically, the first side plate 51 has a circular hole at one end of the first side in the third direction. The drum coupling 60 is located within the circular hole. When the drum cartridge 2 is mounted in the main body frame 910 of the image forming device 900, the drum drive shaft of the image forming device 900 is connected to the drum coupling 60. The rotation of the drum drive shaft is then transmitted to the photosensitive drum 40 via the drum coupling 60.

[0050] The memory 70 is a storage medium capable of storing various pieces of information related to the drum cartridge 2. The information stored in the memory 70 includes, for example, at least one of the following: the serial number of the drum cartridge 2, the cumulative number of rotations of the photosensitive drum 40, the cumulative number of pages printed using the photosensitive drum 40, the compatible model of the drum cartridge 2, the specifications of the drum cartridge 2, information indicating whether the drum cartridge 2 is new or not, information indicating whether the drum cartridge 2 is a genuine product or not, and an error history related to the drum cartridge 2. The memory 70 also stores the number of times the developer cartridge 1 can be replaced with respect to the drum frame 50.

[0051] When the memory 70 stores the cumulative number of rotations or the cumulative number of printed sheets, the control unit 920 of the image forming apparatus 900 updates the cumulative number of rotations or the cumulative number of printed sheets stored in the memory 70 each time a print process is executed. The cumulative number of rotations or the cumulative number of printed sheets may be updated by incrementing from 0 or by decrementing from a predetermined value.

[0052] For example, an IC chip is used for the memory 70. The memory 70 has a conductive electrical contact surface 71.

[0053] The holder 80 is a member that holds the memory 70. The holder 80 is located at the other end of the first side plate 51 in the third direction. FIG. 6 is an exploded perspective view of the memory 70, the holder 80, the coil spring 90, and the drum frame 50. FIG. 7 is a cross-sectional view of the memory 70, the holder 80, the coil spring 90, and the drum frame 50 taken along line AA in FIG. 4. As shown in FIGS. 6 and 7, the holder 80 has a holding surface 81 at one end in the second direction. The memory 70 is held by the holding surface 81. For example, the memory 70 is fixed to the holding surface 81 with an adhesive. Therefore, the electrical contact surface 71 of the memory 70 is located at one end of the holder 80 in the second direction. Even when the developer cartridge 1 is attached to the drum frame 50, the electrical contact surface 71 is not covered by the developer cartridge 1 and is located on the outer surface of the drum frame 50.

[0054] The coil spring 90 is an elastic member that can expand and contract in the second direction. The coil spring 90 is located between the holding surface 81 and the drum frame 50 in the second direction. That is, the coil spring 90 is located between the electrical contact surface 71 of the memory 70 and the drum frame 50 in the second direction. One end of the coil spring 90 in the second direction is connected to the holder 80. The other end of the coil spring 90 in the second direction is connected to the drum frame 50.

[0055] The coil spring 90 is expandable and contractible in the second direction between a first state and a second state in which the coil spring 90 is shorter in the second direction than the first state. The distance in the second direction between the drum frame 50 and the electrical contact surface 71 when the coil spring 90 is in the second state is shorter than the distance in the second direction between the drum frame 50 and the electrical contact surface 71 when the coil spring 90 is in the first state. That is, the holder 80 is movable in the second direction relative to the drum frame 50. When the holder 80 moves in the second direction relative to the drum frame 50, the electrical contact surface 71 of the memory 70 also moves in the second direction relative to the drum frame 50 together with the holder 80.

[0056] As shown in FIGS. 6 and 7 , the holder 80 has a first hole 82 and a second hole 83. The first hole 82 is located at one end of the holder 80 in the first direction. The second hole 83 is located at the other end of the holder 80 in the first direction. The first hole 82 and the second hole 83 may be through holes or concave grooves. The drum frame 50 has a first claw 54 and a second claw 55. The first claw 54 extends from the drum frame 50 toward one side in the second direction, with its tip protruding toward one side in the first direction. The second claw 55 extends from the drum frame 50 toward one side in the second direction, with its tip protruding toward the other side in the first direction. The tip of the first claw 54 fits into the first hole 82. This allows the first claw 54 to engage with the first hole 82. The tip of the second claw 55 fits into the second hole 83. This causes the second claw 55 to engage with the second hole 83. The size of the first hole 82 in the second direction is larger than the size of the first claw 54 in the second direction. The size of the second hole 83 in the second direction is larger than the size of the second claw 55 in the second direction.

[0057] When the coil spring 90 is in the first state described above, the first claw 54 contacts the edge of the first hole 82 of the holder 80 on the other side in the second direction, and the second claw 55 contacts the edge of the second hole 83 of the holder 80 on the other side in the second direction. This limits movement of the holder 80 to the other side in the second direction. Therefore, the holder 80 is prevented from coming off the drum frame 50. Furthermore, when the coil spring 90 is in the second state described above, the first claw 54 moves away from the edge of the first hole 82 of the holder 80 on the other side in the second direction, and the second claw 55 moves away from the edge of the second hole 83 of the holder 80 on the other side in the second direction.

[0058] The first and second claws may be provided on the holder 80. In this case, it is sufficient that the drum frame 50 has a first hole into which the first claw fits and a second hole into which the second claw fits. In other words, it is sufficient that either the drum frame 50 or the holder 80 has a claw, and the other of the drum frame 50 and the holder 80 has a hole into which the claw fits.

[0059] As shown in FIG. 1 , the image forming apparatus 900 has a conductive electrical contact 950. The electrical contact 950 is electrically connected to the control unit 920. When the drum cartridge 2 with the developer cartridge 1 installed is mounted to the main body frame 910 of the image forming apparatus 900, the electrical contact surface 71 of the memory 70 comes into contact with the electrical contact 950. This electrically connects the control unit 920 to the memory 70 via the electrical contact 950 and the electrical contact surface 71. Therefore, the control unit 920 can perform at least one of reading information from the memory 70 and writing information to the memory 70.

[0060] When the electrical contact surface 71 of the memory 70 comes into contact with the electrical contact 950, the coil spring 90 contracts from the first state to the second state. Then, the electrical contact surface 71 moves toward the other side in the second direction relative to the drum frame 50. That is, the distance in the second direction between the drum frame 50 and the electrical contact surface 71 is shortened. This reduces the pressure applied between the electrical contact surface 71 and the electrical contact 950. As a result, rubbing of the electrical contact surface 71 is suppressed.

[0061] After the drum cartridge 2 with the developer cartridge 1 installed is mounted to the main body frame 910, the image forming apparatus 900 may perform a separation operation to temporarily separate the development roller 20 from the photosensitive drum 40. During the separation operation, the casing 10 of the developer cartridge 1 moves toward the other side in the third direction relative to the drum frame 50 of the drum cartridge 2. However, even during the separation operation, the position of the drum frame 50 relative to the main body frame 910 does not change. Therefore, the positions of the electrical contact 950 and the electrical contact surface 71 do not change either. For this reason, even if the holder 80 is not configured to be movable in the third direction relative to the drum frame 50, no friction occurs between the electrical contact 950 and the electrical contact surface 71 during the separation operation.

[0062] Furthermore, in this embodiment, the number of times the developer cartridge 1 has been replaced with respect to the drum cartridge 2 is stored in the memory 70 of the drum cartridge 2. Therefore, even if the developer cartridge 1 does not have a memory, the control unit 920 can read out the number of times the developer cartridge 1 has been replaced from the memory 70 of the drum cartridge 2. Therefore, the control unit 920 can manage the number of times the developer cartridge 1 has been replaced.

[0063] The memory 70 of the drum cartridge 2 may also store at least one of the amount of developer contained in the developer cartridge 1, the dot count that can be printed with the developer, and the number of pages that can be printed with the developer. The memory 70 of the drum cartridge 2 may also store at least one of the cumulative number of rotations of the developer roller 20, the cumulative number of pages printed using the developer roller 20, and the cumulative dot count using the developer roller 20. In this case, the control unit 920 of the image forming apparatus 900 updates the cumulative number of rotations, the cumulative number of pages printed, or the cumulative dot count stored in the memory 70 each time a print process is performed. The cumulative number of rotations, the cumulative number of pages printed, or the cumulative dot count may be updated by incrementing from 0 or by decrementing from a predetermined value. In this way, even if the developer cartridge 1 does not have a memory, the control unit 920 can determine the life of the developer cartridge 1 based on the information stored in the memory 70 of the drum cartridge 2. Therefore, the control unit 920 can notify the user when it is time to replace the developer cartridge 1.

[0064] <4. Modifications> Although one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above embodiment.

[0065] In the above embodiment, the memory 70 having the electrical contact surface 71 is fixed to the outer surface of the holder 80. However, only the electrical contact surface 71 may be disposed on the outer surface of the holder 80, and the portion of the memory 70 other than the electrical contact surface 71 may be disposed in another position on the drum cartridge 2.

[0066] In the above embodiment, the coil spring 90 is used as the elastic member. However, instead of the coil spring 90, other types of elastic members such as a leaf spring, a torsion spring, or rubber may be used.

[0067] In the above embodiment, the developer cartridge 1 includes the developer roller 20. However, the developer cartridge 1 may not include the developer roller 20, and the drum cartridge 2 may include the developer roller 20.

[0068] Furthermore, the detailed shapes of the developing cartridge 1, the drum cartridge 2, and the image forming apparatus 900 may differ from those shown in the drawings of the present application. Furthermore, the elements appearing in the above-described embodiments and modifications may be combined as appropriate within the scope of not causing any contradiction. [Explanation of symbols]

[0069] 1 Developer cartridge 2 drum cartridges 10 Casing 20 Developing roller 30 Gear section 40 Photosensitive drum 50 Drum Frame 54 First Claw 55 Second Claw 60 Drum Coupling 70 memory 71 Electrical Contact Surface 80 Holder 82 Hole 1 83 2nd hole 90 Coil spring 341 gear teeth 351 gear teeth 900 Image forming device 910 main frame 920 Control Unit 950 Electrical Contacts

Claims

1. A drum frame that allows the developer cartridge to be detachably attached; a photosensitive drum rotatable about an axis extending in a first direction; a memory having an electrical contact surface; a holder, the electrical contact surface of which is located on an outer surface in a second direction intersecting the electrical contact surface, the holder being movable in the second direction relative to the drum frame; an elastic member having one end in the second direction connected to the holder, the elastic member being stretchable between a first state and a second state that is shorter in the second direction than the first state; Equipped with the electrical contact surface is located at a first position when the elastic member is in the first state, and is located at a second position away from the first position in the second direction when the elastic member is in the second state; The drum cartridge is characterized in that the electrical contact surface is located on an outer surface of the drum frame when the developing cartridge is attached to the drum frame.

2. A drum frame to which a developing cartridge can be detachably attached; a photosensitive drum rotatable about an axis extending in a first direction; a memory having an electrical contact surface; a holder, the electrical contact surface of which is located on an outer surface in a second direction intersecting the electrical contact surface, the holder being movable in the second direction relative to the drum frame; an elastic member having one end in the second direction connected to the holder, the elastic member being stretchable between a first state and a second state that is shorter in the second direction than the first state; Equipped with the electrical contact surface is located at a first position when the elastic member is in the first state, and is located at a second position away from the first position in the second direction when the elastic member is in the second state; The memory stores a number of times that the developing cartridge can be replaced with respect to the drum frame.

3. A drum frame to which a developing cartridge can be detachably attached; a photosensitive drum rotatable about an axis extending in a first direction; a memory having an electrical contact surface; a holder, the electrical contact surface of which is located on an outer surface in a second direction intersecting the electrical contact surface, the holder being movable in the second direction relative to the drum frame; an elastic member having one end in the second direction connected to the holder, the elastic member being stretchable between a first state and a second state that is shorter in the second direction than the first state; Equipped with the electrical contact surface is located at a first position when the elastic member is in the first state, and is located at a second position away from the first position in the second direction when the elastic member is in the second state; The developing cartridge does not have a memory, a first gear rotatable about an axis extending in the first direction, the first gear having a first engagement portion on a part of an outer periphery thereof; a second gear rotatable about an axis extending in the first direction, the second gear having a second engaging portion that engages with the first engaging portion; A drum cartridge comprising:

4. 4. The drum cartridge according to claim 3, The drum cartridge according to claim 1, wherein the first engagement portion is a plurality of gear teeth along a portion of the outer periphery of the first gear.

5. A drum frame to which a developing cartridge can be detachably attached; a photosensitive drum rotatable about an axis extending in a first direction; a memory having an electrical contact surface; a holder, the electrical contact surface of which is located on an outer surface in a second direction intersecting the electrical contact surface, the holder being movable in the second direction relative to the drum frame; an elastic member having one end in the second direction connected to the holder, the elastic member being stretchable between a first state and a second state that is shorter in the second direction than the first state; Equipped with the electrical contact surface is located at a first position when the elastic member is in the first state, and is located at a second position away from the first position in the second direction when the elastic member is in the second state; The memory stores at least one of the amount of developer contained in the developer cartridge, the dot count that can be printed with the developer, and the number of pages that can be printed with the developer.

6. A drum frame to which a developing cartridge can be detachably attached; a photosensitive drum rotatable about an axis extending in a first direction; a memory having an electrical contact surface; a holder, the electrical contact surface of which is located on an outer surface in a second direction intersecting the electrical contact surface, the holder being movable in the second direction relative to the drum frame; an elastic member having one end in the second direction connected to the holder, the elastic member being stretchable between a first state and a second state that is shorter in the second direction than the first state; Equipped with the electrical contact surface is located at a first position when the elastic member is in the first state, and is located at a second position away from the first position in the second direction when the elastic member is in the second state; One of the drum frame and the holder has a claw, the other of the drum frame and the holder has a hole into which the claw fits, a size of the hole in the second direction being larger than a size of the claw in the second direction;

7. 7. The drum cartridge according to claim 1, The drum cartridge is characterized in that the elastic member is a coil spring.

8. 8. The drum cartridge according to claim 1, The drum cartridge is characterized in that the photosensitive drum is located at one end of the drum frame in a third direction intersecting the first direction.

9. An image forming apparatus comprising the drum cartridge according to any one of claims 1 to 8, The body frame and an electrical contact electrically connectable to the memory, the electrical contact contacting the electrical contact surface when the drum cartridge with the developer cartridge mounted therein is mounted to the main body frame; Equipped with The image forming apparatus, wherein the elastic member contracts from the first state to the second state when the electrical contact surface comes into contact with the electrical contact.

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