Image formation device

Abstract

This image formation device comprises: a drawer 3 that is movable in a first direction with respect to a body housing; and a cartridge 4 that is detachably attached to the drawer. The drawer 3 has a drawer frame 30, a first drawer electrode 73, and a second drawer electrode 74. The cartridge 4 has a cartridge electrode 200 and a side cover 130. The cartridge electrode 200 is electrically connected to the first drawer electrode 73 and the second drawer electrode 74. The side cover 130 is positioned at one end of a developing roller in a second direction intersecting the first direction. The cartridge electrode 200 is positioned on the side cover 130. The drawer frame 30 has a first recess H1 that is recessed in a third direction intersecting the first direction and the second direction. The side cover 130 has a first protrusion C1 that protrudes in the third direction and enters the first recess H1.

Description

Image forming device

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

[0002] A conventional image forming apparatus is known that includes a main body housing, a drawer that is movable relative to the main body housing, and a cartridge that is attachable to and detachable from the drawer (see Patent Document 1). Also, a conventional image forming apparatus is known that includes a main body housing, a drawer that can be pulled out from the main body housing, a cartridge that is attached to the drawer, a pressing member that presses the top surface of the cartridge, a main body cover that opens and closes an opening in the apparatus main body, and an interlocking mechanism that moves the pressing member in conjunction with the operation of closing the main body cover (see Patent Document 2).

[0003] In the image forming apparatus disclosed in Patent Document 1, the drawer has a first electrode. The cartridge has a second electrode that contacts the first electrode. The main body housing also has a control unit. The drawer has a drum circuit board. Each cartridge has a toner circuit board. The control unit is connected to the drum circuit board. The drum circuit board is connected to each of the multiple toner circuit boards.

[0004] In the image forming apparatus of Patent Document 2, a pressing member presses the cartridge in conjunction with the operation of closing the main body cover, so that the drawer is pressed against the main body housing via the cartridge.

[0005] JP 2020-052339 A JP 2008-165026 A

[0006] In the configuration in which the electrodes of the cartridge are brought into contact with the electrodes of the drawer as described in Patent Document 1, it is necessary to improve the positional accuracy of the electrodes of the cartridge relative to the electrodes of the drawer.

[0007] Therefore, one of the objects of the present disclosure is to improve the positional accuracy of the electrodes of the cartridge relative to the electrodes of the drawer.

[0008] Furthermore, in an image forming apparatus such as that described in Patent Document 1, by providing a new electrical circuit that passes through the main body housing, the drawer, and the cartridge, it is possible to use the new electrical circuit for various purposes.

[0009] Therefore, another object of the present disclosure is to provide an image forming apparatus having a new electrical circuit that passes through the main body housing, the drawer, and the cartridge.

[0010] Furthermore, in the image forming apparatus described in Patent Document 2, an interlocking mechanism that interlocks the main body cover and the pressing member is used, which may result in an increase in size of the apparatus.

[0011] Therefore, another object of the present disclosure is to prevent an image forming apparatus that can press a drawer against a main body housing from becoming large.

[0012] In order to solve at least one of the above problems, an image forming apparatus according to a first disclosure of the present application includes a main body housing, a drawer, and a cartridge. The main body housing has a first main body contact and a second main body contact. The drawer is movable in a first direction relative to the main body housing. The drawer has a drawer frame, a first drawer electrode, and a second drawer electrode. The first drawer electrode is electrically connected to the first main body contact. The second drawer electrode is electrically connected to the second main body contact. The cartridge is detachably attached to the drawer. The cartridge has a developing roller, a photosensitive drum, a cartridge electrode, and a side cover. The developing roller has a developing shaft extending in a second direction. The second direction is a direction intersecting the first direction. The photosensitive drum has a drum shaft extending in the second direction. The cartridge electrode is electrically connected to the first drawer electrode and the second drawer electrode. The side cover is located at one end of the developing roller in the second direction. The cartridge electrode is located on the side cover. The drawer frame has a first recess recessed in a third direction, the third direction being a direction intersecting the first and second directions, and the side cover has a first protrusion protruding in the third direction and fitting into the first recess.

[0013] According to the first disclosure, the first protrusion of the side cover having the cartridge electrode fits into the first recess of the drawer frame, thereby improving the positional accuracy of the cartridge electrode relative to the first drawer electrode or the second drawer electrode.

[0014] Furthermore, a second disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the first disclosure: The first convex portion has a surface orthogonal to the first direction.

[0015] Furthermore, a third disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the first disclosure. The cartridge has a cartridge frame. The cartridge frame rotatably supports a developing shaft and a drum shaft. The cartridge electrode has a one-end contact and an other-end contact. The one-end contact is located at one end of the cartridge frame in a first direction. The other-end contact is located at the other end of the cartridge frame in the first direction. The first convex portion is located between the one-end contact and the other-end contact in the first direction.

[0016] Furthermore, a fourth disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the first or second disclosure. The cartridge has a cartridge frame. The cartridge frame has a developer frame and a drum frame. The developer frame rotatably supports a developer shaft. The drum frame rotatably supports the drum shaft. The developer frame is rotatable relative to the drum frame around a rotation axis extending along the second direction. The drawer frame has a second recess recessed in the third direction. The cartridge frame has a second protrusion protruding in the third direction and inserted into the second recess. The rotation axis is located between the first recess and the second recess in the first direction.

[0017] According to the fourth disclosure, the second protrusion of the cartridge frame fits into the second recess of the drawer frame, so that the cartridge can be positioned with high precision relative to the drawer frame.

[0018] Furthermore, a fifth disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the fourth disclosure: the length of the first recess in the first direction is smaller than the length of the second recess in the first direction.

[0019] Furthermore, a sixth disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the fourth disclosure: In the third direction, the bottom surface of the first recess is closer to the rotation axis than the bottom surface of the second recess.

[0020] Furthermore, the seventh disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the first disclosure. The cartridge has a cartridge frame. The cartridge frame has a developer frame, a drum frame, and a cover. The developer frame rotatably supports a developer shaft. The drum frame rotatably supports a drum shaft. The cover holds the developer frame and the drum frame. The cover is located at the other end of the cartridge frame in the second direction. The drawer frame has a third recess recessed in a third direction. The cover has a third protrusion that fits into the third recess.

[0021] According to the seventh disclosure, the third protrusion of the cover fits into the third recess of the drawer frame, so that the cartridge can be positioned with high precision relative to the drawer frame.

[0022] Furthermore, an eighth disclosure of the present application has the following configuration in addition to the configuration of the seventh disclosure: the third convex portion has a cylindrical surface, the cylindrical surface is in contact with the third concave portion, and the cylindrical surface extends in the second direction.

[0023] The ninth disclosure of the present application has the following configuration in addition to the configuration of the seventh disclosure: the third recess has an inclined surface, and the inclined surface is inclined with respect to the first direction.

[0024] Furthermore, a tenth disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the seventh disclosure: A portion of the first convex portion and a portion of the third convex portion are located at the same position in the first direction.

[0025] An eleventh disclosure of the present application has the configuration of the image forming apparatus of any one of the seventh to tenth disclosures, and also has the following configuration: the length of the third convex portion in the second direction is greater than the length of the first convex portion in the second direction.

[0026] In order to solve at least one of the above problems, an image forming apparatus according to a twelfth disclosure of the present application includes a main body housing, a drawer, and a cartridge. The drawer is movable in a first direction relative to the main body housing between an attached position and a pulled-out position. The attached position is the position of the drawer when the drawer is located within the main body housing. The pulled-out position is the position of the drawer when at least a portion of the drawer is located outside the main body housing. The drawer has a drawer frame and a handle. The handle is located at one end of the drawer frame in the first direction. The cartridge is detachably attached to the drawer frame. The cartridge has a developing roller and a photosensitive drum. The developing roller is rotatable about a developing axis extending in a second direction. The second direction is a direction intersecting the first direction. The photosensitive drum is rotatable about a drum axis extending in the second direction. The drawer further includes an elastic member. The elastic member is displaced from the first position to the second position by receiving force from the main body housing when the drawer moves from the pulled-out position to the attached position. The elastic force of the elastic member when in the second position is greater than the elastic force of the elastic member when in the first position. When the elastic member is displaced from the first position to the second position, the elastic member presses the main body housing in one direction of the third direction, and the drawer is pressed in the other direction of the third direction by the elastic force of the elastic member. The third direction is a direction intersecting the first direction and the second direction.

[0027] According to the twelfth disclosure, the elastic member of the drawer presses the drawer against the main body housing as the drawer is attached, thereby preventing the image forming device from becoming larger than, for example, a configuration that includes a linkage mechanism that links the main body cover and the pressing member.

[0028] Furthermore, a thirteenth disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the twelfth disclosure: the elastic member is located at the other end of the drawer frame in the first direction and at one end in the second direction.

[0029] A fourteenth disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the twelfth or thirteenth disclosure: the drawer further has a pressing lever. The pressing lever is supported on the drawer frame so as to be rotatable about a rotation axis along the second direction. The elastic member presses the main body housing via the pressing lever.

[0030] Furthermore, a fifteenth disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the fourteenth disclosure. The drawer frame has a boss extending in a second direction. The pressing lever has a base end and a tip end. The base end has a hole into which the boss fits. The tip end extends from the base end. The tip end protrudes from the drawer frame.

[0031] Furthermore, a sixteenth disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the twelfth disclosure: the main body housing has a main body electrode; the cartridge has a cartridge electrode; the elastic member is conductive; and the elastic member is electrically connected to the main body electrode and the cartridge electrode.

[0032] Furthermore, a seventeenth disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the fourteenth disclosure. The main body housing has a groove. The groove extends in a first direction. The pressing lever fits into the groove. When the drawer is in the attached position, the elastic member presses the pressing lever against the bottom surface of the groove.

[0033] Furthermore, the eighteenth disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the twelfth disclosure: the drawer frame has a pressing protrusion at the other end in the first direction and the other end in the second direction, the pressing protrusion extending in the second direction, and the pressing protrusion pressing the drawer toward one end in the second direction.

[0034] Furthermore, a nineteenth disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the eighteenth disclosure. The cartridge has a development coupling and a drum coupling. The development coupling transmits a driving force to the development roller. The development coupling is located at the other end of the cartridge in the second direction. The drum coupling transmits a driving force to the photosensitive drum. The drum coupling is located at the other end of the cartridge in the second direction. The pressing protrusion is located at a position different from the development coupling and the drum coupling in the third direction.

[0035] According to the 19th disclosure, since the pressing protrusion is located at a position different from the development coupling and the drum coupling in the third direction, it is possible to prevent the pressing protrusion from coming into contact with a component on the main body housing side that is connected to the development coupling or the drum coupling when the drawer moves.

[0036] Furthermore, a twentieth disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the twelfth disclosure: the main body housing has a cartridge pressing portion that presses the cartridge in a third direction.

[0037] Furthermore, the 21st disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the 20th disclosure. The drawer frame has two recesses. The two recesses position the cartridge. The two recesses are aligned in a first direction. The cartridge has a contact portion that contacts the cartridge pressing portion. The contact portion is located between the two recesses in the first direction.

[0038] Furthermore, the 22nd disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the 12th disclosure. The main body housing has two bosses. The bosses extend in a second direction. The two bosses are spaced apart in the second direction. The drawer frame has two recesses. The two recesses are located at the other end of the drawer frame in the first direction. The two recesses are spaced apart in the second direction. The two recesses are recessed in the first direction. When the drawer is in the attached position, the bosses fit into the recesses.

[0039] According to the twenty-second disclosure, the boss of the main body housing fits into the recess of the drawer frame, so that the drawer can be positioned with high precision relative to the main body housing.

[0040] Furthermore, a 23rd disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the 22nd disclosure: the image forming apparatus includes a belt unit. The belt unit has a belt that contacts a photosensitive drum. The main body housing has side frames that support the belt unit. The side frames have bosses.

[0041] According to the twenty-third disclosure, the side frames that support the belt unit have bosses for positioning the drawer, so that the drawer can be positioned with high precision relative to the belt unit.

[0042] Furthermore, a 24th disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the 23rd disclosure: the side frame has a main body-side convex portion that protrudes in one direction of the third direction; the drawer frame has a drawer-side convex portion that protrudes in the other direction of the third direction; when the drawer is in the attached position, the main body-side convex portion comes into contact with the drawer-side convex portion.

[0043] According to the twenty-fourth disclosure, the main body-side protrusions come into contact with the drawer-side protrusions, so the drawer can be positioned with high precision relative to the side frame.

[0044] Furthermore, the 25th disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the 12th disclosure: the drawer frame has a side surface and a guide rail. The side surface intersects with the second direction. The guide rail protrudes from the side surface. The guide rail extends in the first direction. The guide rail is guided by the main body housing.

[0045] Furthermore, the 26th disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the 25th disclosure. The guide rail has a convex portion. The convex portion is located at the end of the guide rail in the first direction. The convex portion has an R-shape that is convex in the third direction. The main body housing has a concave portion. The concave portion is a concave portion into which the convex portion of the guide rail fits when the drawer is in the attached position. The concave portion is concave in the third direction.

[0046] The image forming apparatus of the present application according to the twenty-sixth disclosure has the following configuration: the recess has an inclined surface, and the inclined surface is inclined toward one of the upstream side in the attachment direction of the drawer and the third direction.

[0047] According to the 27th disclosure, when the drawer is pulled out from the main body housing, the convex portion of the drawer slides along the inclined surface, so that the drawer can be pulled out smoothly.

[0048] Furthermore, a 28th disclosure of the present application has the configuration of the image forming apparatus of any one of the 25th to 27th disclosures, and also has the following configuration: the drawer frame has a boss. The boss is located at one end of a side surface of the drawer frame in a first direction. The boss protrudes from the side surface. The main body housing has a drawer pressing portion that presses the boss in a third direction.

[0049] The twenty-ninth disclosure of the present application has the following configuration in addition to the configuration of the twenty-eighth disclosure: the boss is located at a position different from the guide rail in the third direction.

[0050] Furthermore, the 30th disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the 12th disclosure: the cartridge is attached to the drawer frame in the other direction of the third direction and is removed from the drawer frame in one direction of the third direction.

[0051] The thirty-first disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the twelfth disclosure: The photosensitive drum is located at the other end of the cartridge in the third direction.

[0052] In order to solve at least one of the above problems, an image forming apparatus according to a thirty-second disclosure of the present application includes a main body housing, a drawer, and first and second cartridges. The drawer is movable in a first direction relative to the main body housing. The first and second cartridges are detachably attached to the drawer. The first and second cartridges are aligned in the first direction. The main body housing has a first main body contact and a second main body contact. The drawer has a drawer frame, a first drawer electrode, and a second drawer electrode. The first drawer electrode is electrically connected to the first main body contact. The first drawer electrode is located at one end of the drawer frame in the first direction. The second drawer electrode is electrically connected to the second main body contact. The second drawer electrode is located at the other end of the drawer frame in the first direction. The first cartridge includes a first cartridge frame, a first developing roller, a first photosensitive drum, and a first cartridge electrode. The first developing roller has a first developing shaft extending in a second direction. The second direction intersects with the first direction. The first photosensitive drum has a first drum shaft extending in the second direction. The first cartridge electrode has a first one-end contact, a first other-end contact, and a first electrode body. The first one-end contact is located at one end of the first cartridge frame in the first direction. The first other-end contact is located at the other end of the first cartridge frame in the first direction. The first electrode body extends from the first one-end contact to the first other-end contact. The second cartridge has a second cartridge frame, a second developing roller, a second photosensitive drum, and a second cartridge electrode. The second developing roller has a second developing shaft extending in the second direction. The second photosensitive drum has a second drum shaft extending in the second direction. The second cartridge electrode has a second one-end contact, a second other-end contact, and a second electrode body. The second one-end contact is located at one end of the second cartridge frame in the first direction. The second other-end contact is located at the other end of the second cartridge frame in the first direction. The second electrode body extends from the second one-end contact to the second other-end contact. The first drawer electrode is electrically connected to the first one-end contact.The first other-end contact is electrically connected to the second one-end contact, and the second other-end contact is electrically connected to the second drawer electrode.

[0053] According to the thirty-second disclosure, the first main body contact, the first drawer electrode, the first cartridge electrode, the second cartridge electrode, the second drawer electrode, and the second main body contact are electrically connected, thereby forming an electric circuit that passes current from the first main body contact to the second main body contact via the first drawer electrode, the first cartridge electrode, the second cartridge electrode, and the second drawer electrode. This makes it possible to provide an image forming apparatus having a new electric circuit that passes through the main body housing, the drawer, and the cartridge.

[0054] The thirty-third disclosure of the present application has the following configuration in addition to the configuration of the thirty-second disclosure of the image forming apparatus: The first one-end contact is movable in a first direction.

[0055] Furthermore, the 34th disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the 32nd disclosure. The first cartridge includes a first developing coupling and a first drum coupling. The first developing coupling transmits driving force to the first developing roller. The first drum coupling transmits driving force to the first photosensitive drum. The first cartridge frame has one end and the other end. The one end is located at one end of the first cartridge frame in the second direction. The other end is located at the other end of the first cartridge frame in the second direction. The first cartridge electrode is located at one end of the first cartridge frame. The first developing coupling and the first drum coupling are located at the other end of the first cartridge frame.

[0056] The thirty-fifth disclosure of the present application has the following configuration in addition to the configuration of the thirty-fourth disclosure of the image forming apparatus: the first cartridge includes a first developer electrode; the first developer electrode is electrically connected to a first developer shaft; and the first developer electrode is located at one end of a first cartridge frame.

[0057] Furthermore, the 36th disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the 34th disclosure. The first cartridge frame includes a first drum frame, a first developing frame, and a first side cover. The first drum frame rotatably supports the first drum shaft. The first developing frame rotatably supports the first developing shaft. The first developing frame is rotatable relative to the first drum frame. The first side cover holds the first drum frame and the first developing frame. The first side cover is located at one end of the first cartridge frame. The first cartridge electrode is located on the first side cover.

[0058] Furthermore, the 37th disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the 32nd disclosure. The first cartridge has an inclined surface. The inclined surface is inclined with respect to a first direction. The inclined surface is located at the other end of the first cartridge frame in the first direction. At least a portion of the inclined surface is located at the same position as the first other-end contact in the second direction, and is located upstream of the first other-end contact in the mounting direction of the first cartridge.

[0059] The 38th disclosure of the present application has the following configuration in addition to the configuration of the 37th disclosure: the length of the inclined surface in the second direction is greater than the length of the first one-end contact in the second direction.

[0060] The 39th disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the 38th disclosure: the length of the first one-end contact in the second direction is shorter than the length of the first other-end contact in the second direction.

[0061] The fortieth disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the thirty-second disclosure: the first drawer electrode has a first drawer contact electrically connected to the first one-end contact, and the second drawer electrode has a second drawer contact electrically connected to the second other-end contact.

[0062] The forty-first disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the fortieth disclosure: The second drawer contact is movable in a first direction.

[0063] Furthermore, a 42nd disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the 40th disclosure. The drawer has a connector. The connector is electrically connected to the first drawer electrode. The connector is supplied with power from the first main body contact. The drawer frame has one end and the other end. The one end is located at one end of the drawer frame in the second direction. The other end is located at the other end of the drawer frame in the second direction. The second drawer contact is located at one end of the drawer frame. The connector is located at the other end of the drawer frame.

[0064] Furthermore, a 43rd disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the 40th disclosure. The drawer has a conductive member. The conductive member is electrically connected to the second drawer electrode and the second main body contact. The conductive member is located at the other end of the drawer frame in the first direction. The conductive member protrudes from the drawer frame in a third direction intersecting the first direction and the second direction.

[0065] Furthermore, a 44th disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the 43rd disclosure: the drawer has a conductive spring. The spring biases the conductive member toward the second main body contact. The spring is electrically connected to the second drawer electrode and the conductive member.

[0066] The 45th disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the 40th disclosure: The image forming apparatus includes a control unit, and the control unit determines whether all cartridges are installed in the drawers based on the electrical connection state of a circuit including the first main body contact, the first drawer electrode, the first cartridge electrode, the second cartridge electrode, the second drawer electrode, and the second main body contact.

[0067] Furthermore, the 46th disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the 40th disclosure. The drawer frame has a guide surface. The guide surface guides the first cartridge in a third direction intersecting the first direction and the second direction. The first cartridge frame has a guided surface. The guided surface is guided by the guide surface by coming into contact with the guide surface. The guided surface is located downstream of the first other-end contact in the cartridge mounting direction.

[0068] The 47th disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of the 40th disclosure: the drawer has a handle, and the handle is located at one end of the drawer frame in the first direction.

[0069] The 48th disclosure of the present application has the following configuration in addition to the configuration of the 40th disclosure of the image forming apparatus: The first direction is perpendicular to the second direction.

[0070] The 49th disclosure of the present application has the following configuration in addition to the configuration of the image forming apparatus of any one of the 32nd to 48th disclosures: the second cartridge electrode has an elastic portion that biases the first cartridge in the first direction.

[0071] According to the present disclosure, it is possible to improve the positional accuracy of the cartridge electrodes relative to the drawer electrodes. Furthermore, according to the present disclosure, it is possible to prevent the size of an image forming apparatus from increasing, which allows the drawer to be pressed against the main body housing. Furthermore, according to the present disclosure, it is possible to provide an image forming apparatus having a new electrical circuit that passes through the main body housing, the drawer, and the cartridge.

[0072] 1 is a perspective view showing an image forming apparatus with the drawer pulled out; FIG. 2 is a perspective view showing the drawer in the installed position; FIG. 3 is a cross-sectional view showing the cartridge; FIG. 4 is a perspective view of the inside of the main body housing as seen from one side in the second direction and one side in the third direction; FIG. 5(a) is a perspective view of the inside of the main body housing as seen from the other side in the second direction and the other side in the third direction, and FIG. 5(b) is an enlarged view showing the structure around the second main body electrode; FIG. 6 is a perspective view of the drawer as seen from the other side in the first direction and the other side in the second direction; FIG. 7 is a perspective view of the drawer as seen from one side in the first direction and the other side in the second direction; FIG. 8 is a perspective view of the drawer as seen from one side in the first direction and the other side in the second direction; FIG. 9 is a diagram showing the structure around the pressing lever, with FIG. 9(a) showing the pressing lever in the first lever position and FIG. 9(b) showing the pressing lever in the second lever position; FIG. 10 is a diagram showing the movement of the pressing member when the drawer moves toward the installed position; FIG. 11 is a perspective view of the cartridge as seen from one side in the second direction; FIG. 12 is a perspective view showing the cartridge with the side cover removed; and FIG. 13 is a perspective view of the cartridge as seen from the other side in the second direction. 1A is a perspective view showing the relationship between the side cover and cartridge electrodes, and FIG. 1B is a perspective view showing the cartridge electrodes. FIG. 1A is a side view of the drawer with the cartridge installed, viewed from one side in the second direction, and FIG. 1B is an enlarged view showing the first recess and the second recess in an enlarged manner. FIG. 1A is a side view of the drawer with the cartridge installed, viewed from the other side in the second direction, and FIG. 1B is an enlarged view showing the third recess and the fourth recess in an enlarged manner. FIG. 1A to FIG. 1C are views showing the lengths of the first recess and the second recess in the second direction. FIG. 1A is a perspective view showing the state in which the second cartridge is being installed in a drawer with cartridges other than the second cartridge installed. FIG. 1A is a view showing the state in which the contacts on one end of the second cartridge are guided by the inclined surface of the first cartridge, and FIG. 1B is a view showing the state in which the first protrusion of the second cartridge is guided by the guide surface of the drawer. FIG. 1A is a view showing the relationship between the contacts on one end of the second cartridge and the inclined surface of the first cartridge, and FIG. 1B is a view showing the relationship between the contacts on one end of the second cartridge and the contacts on the other end of the first cartridge. 1A is a diagram showing the relationship between the recessed portion of the drawer and the boss of the side frame, and FIG. 1B is a diagram showing the state in which the side frame supports the belt unit. 1C is a diagram showing the state in which the protrusion on the drawer is supported by the protrusion on the main body.1A to 1C show the state in which the guide rail of the drawer is guided by the guide surface of the main body housing. 1A to 1C show the relationship between the guide rail, the guide surface of the main body housing, and the recess when the drawer is in the attached position. 1A to 1C show the state in which the pressing protrusion of the drawer is pressed by the cam surface of the main body housing when the drawer moves toward the attached position. 1A to 1C show the state in which the pressing protrusion passes between the development joint and the drum joint when the drawer moves. 1A and 1B are perspective views showing modified examples in which the position of the pressing protrusion is changed. 1A and 1B show modified examples in which the pitch of the third recess is set to a different pitch depending on the model.

[0073] Next, an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. As shown in Fig. 1, the image forming apparatus 1 is a color printer. The image forming apparatus 1 includes a main body 2, a drawer 3, and four cartridges 4.

[0074] In the following description, when directions are described, the first, second, and third directions shown in the drawings will be used. In this embodiment, the second direction is perpendicular to the first direction. The third direction is perpendicular to the first and second directions. Also, the arrows indicating each direction in the drawings will point to one side in each direction. Also, the end on one side will be referred to as "one end," and the end on the other side will be referred to as "the other end."

[0075] The main body housing 2 has an opening 2A and a main body cover 21. The opening 2A is an opening through which the drawer 3 can pass. The main body cover 21 opens and closes the opening 2A.

[0076] The drawer 3 is movable in a first direction relative to the main body housing 2. The drawer 3 is movable between a mounted position shown in FIG. 2 and a pulled-out position shown in FIG.

[0077] The mounted position is the position of the drawer 3 when it is located inside the main body housing 2. When the drawer 3 is located in the mounted position, it is possible to print on sheets. The pulled-out position is the position of the drawer 3 when at least a portion of the drawer 3 is located outside the main body housing 2. The pulled-out position is located on one side of the mounted position in the first direction. When the drawer 3 is located in the pulled-out position, it is possible to attach and detach the cartridge 4 to the drawer 3.

[0078] The drawer 3 includes a drawer frame 30 and a handle 30A. The handle 30A is located at one end of the drawer frame 30 in the first direction.

[0079] The cartridge 4 is detachable from the drawer frame 30. Specifically, the cartridge 4 is attached to the drawer frame 30 in the other direction of the third direction. The cartridge 4 is removed from the drawer frame 30 in one direction of the third direction.

[0080] The four cartridges 4 are lined up in the first direction when attached to the drawer frame 30. The four cartridges 4 have the same structure. Each of the four cartridges 4 is filled with toner of a different color. In the following description, the cartridges 4 will also be referred to as the first cartridge 4A, the second cartridge 4B, the third cartridge 4C, and the fourth cartridge 4D, starting from one side in the first direction. In addition, the names of the components constituting the first cartridge 4A may be prefixed with "first" and the reference numerals may end with "A." Similarly, the names of the components constituting the other cartridges may be prefixed with "second, B," "third, C," or "fourth, D," respectively.

[0081] 3, the cartridge 4 has a photosensitive drum 41, a charging roller 42, a developing roller 43, a supply roller 44, and a cartridge frame 100. In other words, the first cartridge 4A has a first photosensitive drum 41A, a first charging roller 42A, a first developing roller 43A, a first supply roller 44A, and a first cartridge frame 100A. The second cartridge 4B has a second photosensitive drum 41B, a second charging roller 42B, a second developing roller 43B, a second supply roller 44B, and a second cartridge frame 100B. The third cartridge 4C and the fourth cartridge 4D also have the aforementioned components.

[0082] The photosensitive drum 41 is rotatable about a drum axis X1 extending in the second direction. The photosensitive drum 41 is located at the other end of the cartridge 4 in the third direction. The surface of the photosensitive drum 41 is charged by a charging roller 42. The charged surface of the photosensitive drum 41 is exposed to light by a scanner (not shown).

[0083] The charging roller 42 is a roller that charges the surface of the photosensitive drum 41. The charging roller 42 is in contact with the photosensitive drum 41. The charging roller 42 is rotatable about a charging axis X2 that extends in the second direction.

[0084] The developing roller 43 is a roller that supplies toner to the photosensitive drum 41. The developing roller 43 contacts the photosensitive drum 41. The developing roller 43 is rotatable about a development axis X3 that extends in the second direction.

[0085] The supply roller 44 is a roller that supplies toner to the developing roller 43. The supply roller 44 contacts the developing roller 43. The supply roller 44 is rotatable about a supply axis X4 that extends in the second direction.

[0086] 4, the image forming apparatus 1 further includes a belt unit 5, a fixing device (not shown), and a control unit 6. The belt unit 5 has a belt 51. The belt 51 is a belt onto which a toner image is transferred from each cartridge 4. The belt 51 comes into contact with the photosensitive drum 41.

[0087] The control unit 6 is capable of executing printing control. When the control unit 6 performs printing control, conveyance of a sheet (not shown) is started, and a toner image is transferred from the belt 51 to the sheet. When the sheet passes through the fixing device, the toner image is fixed to the sheet. After passing through the fixing device, the sheet is discharged outside the main body housing 2.

[0088] The main body housing 2 further includes four development joints J1, four drum joints J2, a first main body electrode 71, two side frames 22 and 23, and an upper frame 24.

[0089] The development joint J1 is a member that transmits a driving force to the development roller 43. The four development joints J1 are arranged at intervals in the first direction. Each development joint J1 is movable in the second direction.

[0090] The drum joint J2 is a member that transmits driving force to the photosensitive drum 41. The four drum joints J2 are aligned at intervals in the first direction. Each drum joint J2 is located on the other side of the developing joint J1 in the third direction. Each drum joint J2 is movable in the second direction.

[0091] The first body electrode 71 is connected to the control unit 6 via wiring (not shown). The first body electrode 71 has a first body contact 71 A. The first body electrode 71 is movable in a second direction.

[0092] The side frame 22 is located at one end in the second direction of the main body housing 2. The side frame 23 is located at the other end in the second direction of the main body housing 2. The two side frames 22, 23 support the belt unit 5.

[0093] Each development joint J1, each drum joint J2, and the first body electrode 71 are located on the side frame 23 on the other end side in the second direction. Each development joint J1, each drum joint J2, and the first body electrode 71 move in one direction in the second direction in conjunction with the operation of closing the body cover 21. Each development joint J1, each drum joint J2, and the first body electrode 71 move in the other direction in conjunction with the operation of opening the body cover 21.

[0094] The interlocking of each development joint J1, each drum joint J2, and the first body electrode 71 with the body cover 21 can be performed mechanically, for example, by an interlocking mechanism that interlocks with the movement of the body cover 21. Alternatively, the interlocking of each development joint J1, each drum joint J2, and the first body electrode 71 with the body cover 21 may be performed by the control unit 6 controlling a drive source for moving each development joint J1, each drum joint J2, and the first body electrode 71 based on the result of detecting whether the body cover 21 is opened or closed.

[0095] The upper frame 24 connects one ends of the side frames 22, 23 in the third direction. As shown in Fig. 5(a) , the upper frame 24 has a groove 25. The groove 25 extends in the first direction. The groove 25 is recessed from a surface located at the other end of the upper frame 24 in the third direction. The groove 25 opens toward the other side in the third direction and toward one side in the first direction.

[0096] 5(a) and 5(b), the groove 25 has a first bottom surface 25A, a second bottom surface 25B, a third bottom surface 25C, and a fourth bottom surface 25D. The first bottom surface 25A is perpendicular to the third direction. The first bottom surface 25A extends in the first direction from one end of the upper frame 24 to the other end in the first direction.

[0097] The second bottom surface 25B extends from the other end of the first bottom surface 25A in the first direction toward the other end in the third direction. The second bottom surface 25B is perpendicular to the first bottom surface 25A.

[0098] The third bottom surface 25C extends from the other end of the second bottom surface 25B in the third direction toward the other end in the third direction and the other end in the first direction. The third bottom surface 25C is inclined with respect to the first bottom surface 25A.

[0099] The fourth bottom surface 25D extends from the other end of the third bottom surface 25C in the first direction toward the other side in the first direction. The fourth bottom surface 25D is perpendicular to the third direction.

[0100] The main body housing 2 further has a second main body electrode 72 , a main body charging electrode 81 , a main body drum electrode 82 , a main body developing electrode 83 , a main body supply electrode 84 , and a main body memory electrode 85 .

[0101] The second body electrode 72, the body-side charging electrode 81, the body-side developing electrode 83, the body-side supply electrode 84, and the body-side memory electrode 85 are each connected to the control unit 6 by wiring (not shown). The body-side drum electrode 82 is grounded.

[0102] The second body electrode 72 has a second body contact 72 A. The second body electrode 72 is located on the fourth bottom surface 25 D of the groove 25 of the upper frame 24 .

[0103] The main body-side charging electrode 81, main body-side drum electrode 82, main body-side developing electrode 83, main body-side supply electrode 84, and main body-side memory electrode 85 are located on one end of the side frame 22 in the second direction. The main body-side charging electrode 81 is an electrode that supplies power to the charging roller 42. The main body-side drum electrode 82 is an electrode that grounds the photosensitive drum 41.

[0104] The main body side developing electrode 83 is an electrode that supplies power to the developing roller 43. The main body side supply electrode 84 is an electrode that supplies power to the supply roller 44. The main body side memory electrode 85 is an electrode that supplies power to a cartridge memory M, which will be described later.

[0105] As shown in FIG. 6 , the drawer frame 30 has a first wall 31, a second wall 32, a third wall 33, a fourth wall 34, a fifth wall 35, four beams 36, two guide rails 37, and a pressing protrusion 38.

[0106] The first wall 31 is located at one end in the first direction of the drawer frame 30. The first wall 31 extends in the second direction. The first wall 31 has a handle 30A.

[0107] The second wall 32 is located at the other end in the first direction of the drawer frame 30. The second wall 32 extends in the second direction.

[0108] The third wall 33 is located at one end of the drawer frame 30 in the second direction. The third wall 33 connects one end of the first wall 31 in the second direction to one end of the second wall 32 in the second direction. The third wall 33 has a plurality of terminals 33A. When the drawer 3 is located in the installation position, each terminal 33A contacts the main body memory electrode 85 shown in FIG. 5A. When the drawer 3 is located in the installation position, the main body charging electrode 81, main body drum electrode 82, main body developer electrode 83, and main body supply electrode 84 shown in FIG. 5A are located on one side of the third wall 33 in the third direction.

[0109] The fourth wall 34 is located at one end of the drawer frame 30 in the second direction and the other end in the third direction. The fourth wall 34 is located at the other end of the third wall 33 in the third direction. The fourth wall 34 connects one end of the first wall 31 in the second direction and one end of the second wall 32 in the second direction. The fourth wall 34 has a side surface 34A. The side surface 34A is a surface that intersects with the second direction. In this embodiment, the side surface 34A is perpendicular to the second direction. The side surface 34A faces one side of the second direction.

[0110] The fifth wall 35 is located at the other end of the drawer frame 30 in the second direction and the other end in the third direction. The fifth wall 35 connects the other end of the first wall 31 in the second direction to the other end of the second wall 32 in the second direction. The fifth wall 35 has a side surface 35A. The side surface 35A is a surface that intersects with the second direction. In this embodiment, the side surface 35A is perpendicular to the second direction. The side surface 35A faces the other side of the second direction.

[0111] The four beams 36 connect the fourth wall 34 and the fifth wall 35. The four beams 36 are arranged at intervals in the first direction.

[0112] The two guide rails 37 are guided by the main body housing 2. One of the two guide rails 37 protrudes from a side surface 34A of the fourth wall 34. The other guide rail 37 protrudes from a side surface 35A of the fifth wall 35. Each guide rail 37 extends in a first direction.

[0113] Each guide rail 37 has a base portion 37A and a protruding portion 37B. The base portion 37A extends in a first direction. The protruding portion 37B is located at the other end of the base portion 37A in the first direction. The protruding portion 37B is convex toward the other end in the third direction. The protruding portion 37B has an R-shape.

[0114] The pressing protrusion 38 is a protrusion for pressing the drawer 3 toward one end in the second direction. The pressing protrusion 38 is located at the other end in the first direction of the drawer frame 30 and the other end in the second direction. More specifically, the pressing protrusion 38 is located at the other end in the second direction of the second wall 32.

[0115] The pressing protrusion 38 extends in the second direction. The pressing protrusion 38 is movable in the second direction. The second wall 32 has a hole 32A into which the pressing protrusion 38 fits. A spring is disposed between the bottom of the hole 32A and the pressing protrusion 38.

[0116] The drawer 3 further includes a first drawer electrode 73, a second drawer electrode 74 shown in FIG. 7 , a connector 75, and a push lever 76. The first drawer electrode 73 and the second drawer electrode 74 are made of sheet metal. The connector 75 has metal terminals and a resin cover that houses the terminals. The push lever 76 is a conductive member made of a conductive resin or the like.

[0117] The first drawer electrode 73 is an electrode electrically connected to the first main body contact 71A shown in FIG. 4 via the connector 75. The first drawer electrode 73 is located at one end of the drawer frame 30 in the first direction and one end in the second direction. More specifically, the first drawer electrode 73 is located at one end of the first wall 31 in the second direction. A portion of the first drawer electrode 73 is located within the first wall 31, and the other portion is exposed from the surface of the first wall 31 facing the second wall 32. The first drawer electrode 73 has a first drawer contact 73A in the portion exposed from the first wall 31.

[0118] The connector 75 is a member to which power is supplied from the first body contact 71A. The connector 75 is located at the other end of the drawer frame 30 in the second direction. More specifically, the connector 75 is located at the other end of the first wall 31 in the second direction. The connector 75 is electrically connected to the first drawer electrode 73. More specifically, the connector 75 is connected to the first drawer electrode 73 by wiring (not shown). The connector 75 is exposed toward the other side in the second direction. The connector 75 is capable of contacting the first body contact 71A.

[0119] 7, the second drawer electrode 74 is an electrode electrically connected to the second body contact 72A shown in FIG. 5 via the pressing lever 76. The second drawer electrode 74 and the pressing lever 76 are located at the other end of the drawer frame 30 in the first direction and at one end in the second direction. More specifically, the second drawer electrode 74 and the pressing lever 76 are located at one end of the second wall 32 in the second direction.

[0120] As shown in FIG. 8( a), a portion of the second drawer electrode 74 is located within the second wall 32, and another portion is exposed from the surface of the second wall 32 facing the first wall 31. The second drawer electrode 74 has a second drawer contact 74A and an elastic portion 74B. The second drawer contact 74A is located on the portion of the second drawer electrode 74 that is exposed from the second wall 32. The second drawer contact 74A is movable in a first direction. The elastic portion 74B biases the second drawer contact 74A toward the fourth cartridge 4D when the fourth cartridge 4D is attached to the drawer 3.

[0121] The pressing lever 76 is supported by the second wall 32 so as to be rotatable about a rotation axis X5 along the second direction. The pressing lever 76 is rotatable between a first lever position shown in Fig. 8(a) and a second lever position shown in Fig. 8(b). The second wall 32 has a boss 32B extending in the second direction.

[0122] The pressing lever 76 has a base end 76A and a tip end 76B. The base end 76A has a hole 76C into which the boss 32B is inserted. The tip end 76B extends from the base end 76A. The tip end 76B protrudes from the second wall 32 in one direction in the third direction.

[0123] 9(a) to 9(c), when the drawer 3 is located at any position between the attached position and the pulled-out position, the pressing lever 76 is in the groove 25 of the main body housing 2. As shown in FIGS. 9(b) and 9(c), when the drawer 3 moves from the pulled-out position to the attached position, the pressing lever 76 comes into contact with the second bottom surface 25B or the third bottom surface 25C of the groove 25, thereby rotating from the first lever position to the second lever position. When the drawer 3 is located at the attached position, the pressing lever 76 comes into contact with the second main body contact 72A and is electrically connected to the second main body contact 72A.

[0124] As shown in FIG. 8B , the drawer 3 further includes an elastic member 77. The elastic member 77 is a conductive torsion spring made of metal or the like. Like the second drawer electrode 74 and the pressing lever 76, the elastic member 77 is located at the other end of the drawer frame 30 in the first direction and at one end in the second direction. The boss 32B is inserted into the coil portion of the elastic member 77.

[0125] One end of the elastic member 77 contacts the second drawer electrode 74. The other end of the elastic member 77 contacts the pressing lever 76. As a result, the elastic member 77 is electrically connected to the second drawer electrode 74 and the pressing lever 76. Furthermore, the pressing lever 76 is electrically connected to the second drawer electrode 74 via the elastic member 77. The elastic member 77 is electrically connected to the second main body electrode 72 via the pressing lever 76.

[0126] The elastic member 77 is displaceable between a first position shown in Fig. 8(a) and a second position shown in Fig. 8(b). The elastic force of the elastic member 77 in the second position is greater than the elastic force of the elastic member 77 in the first position.

[0127] 9(b) and 9(c), when the drawer 3 moves from the pulled-out position to the attached position, the elastic member 77 receives a force from the main body housing 2 and is displaced from the first position to the second position. When the elastic member 77 is displaced from the first position to the second position, the elastic member 77 presses the main body housing 2 in one direction in the third direction via the pressing lever 76, and the drawer 3 is pressed in the other direction in the third direction by the elastic force of the elastic member 77.

[0128] When the drawer 3 is in the attached position, the elastic member 77 presses the pressing lever 76 against the fourth bottom surface 25D of the groove 25. More specifically, when the drawer 3 is in the attached position, the elastic member 77 biases the pressing lever 76 against the second main body contact 72A.

[0129] 10 , the cartridge 4 further includes a charging electrode 91, a drum electrode 92, a developing electrode 93, a supplying electrode 94, a cartridge memory M, and a cartridge electrode 200. The charging electrode 91, the drum electrode 92, the developing electrode 93, the supplying electrode 94, the cartridge memory M, and the cartridge electrode 200 are located at one end of the cartridge frame 100 in the second direction.

[0130] The charging electrode 91 is electrically connected to the charging roller 42. The charging electrode 91 is connected to the charging roller 42 by wiring (not shown). When the drawer 3 is in the attached position, the charging electrode 91 contacts the main body side charging electrode 81.

[0131] 11 , the photosensitive drum 41 has a drum shaft 411 extending in the second direction. The developing roller 43 has a developing shaft 431 extending in the second direction. The supply roller 44 has a supply shaft 441 extending in the second direction.

[0132] The drum electrode 92 is electrically connected to the drum shaft 411. The drum electrode 92 is connected to the drum shaft 411 by wiring (not shown). When the drawer 3 is in the attached position, the drum electrode 92 comes into contact with the main body side drum electrode 82.

[0133] The developing electrode 93 is electrically connected to the developing shaft 431. The developing electrode 93 is connected to the developing shaft 431 by wiring (not shown). When the drawer 3 is in the attached position, the developing electrode 93 contacts the main body side developing electrode 83.

[0134] The supply electrode 94 is electrically connected to the supply shaft 441. The supply electrode 94 is connected to the supply shaft 441 by wiring (not shown). When the drawer 3 is in the attached position, the supply electrode 94 comes into contact with the main body side supply electrode 84.

[0135] The cartridge memory M has a plurality of memory electrodes 95. When the drawer 3 is in the mounted position, the memory electrodes 95 come into contact with the terminals 33A of the drawer 3. As a result, when the drawer 3 is in the mounted position, the memory electrodes 95 are electrically connected to the main body-side memory electrodes 85 via the terminals 33A of the drawer 3.

[0136] The cartridge electrode 200 is an electrode for relaying the first drawer electrode 73 and the second drawer electrode 74. The structure of the cartridge electrode 200 will be described in detail later.

[0137] 12, the cartridge 4 further includes a development coupling CP1 and a drum coupling CP2. The development coupling CP1 and the drum coupling CP2 are located at the other end of the cartridge 4 in the second direction.

[0138] The developing coupling CP1 is a member that transmits the driving force transmitted from the developing joint J1 to the developing roller 43. The developing joint J1 can be inserted into or removed from the developing coupling CP1.

[0139] The drum coupling CP2 is a member that transmits the driving force transmitted from the drum joint J2 to the photosensitive drum 41. The drum joint J2 can be inserted into or removed from the drum coupling CP2. The drum coupling CP2 is located at a position away from the development coupling CP1. The drum coupling CP2 is located on the other side in the third direction and on one side in the first direction relative to the development coupling CP1.

[0140] The cartridge frame 100 includes a developer frame 110, a drum frame 120, a side cover 130, and a cover 140. The side cover 130 is located at one end of the cartridge frame 100 in the second direction. The cover 140 is located at the other end of the cartridge frame 100 in the second direction.

[0141] In other words, the side cover 130 is located at one end of the developing roller 43 in the second direction, and the cover 140 is located at the other end of the developing roller 43 in the second direction.

[0142] 11 , the developing frame 110 rotatably supports the developing shaft 431. The developing frame 110 is located on the other side of the drum frame 120 in the first direction. The developing frame 110 is rotatable relative to the drum frame 120 about a rotation axis X6 extending in the second direction. Specifically, the developing frame 110 is rotatable between a contact position where the developing roller 43 contacts the photosensitive drum 41 and a separation position where the developing roller 43 is separated from the photosensitive drum 41.

[0143] The developing frame 110 has a cylindrical boss 111 centered on the rotation axis X6. The developing electrode 93 and the supply electrode 94 are located at one end of the developing frame 110 in the second direction.

[0144] The drum frame 120 rotatably supports the drum shaft 411 via the side cover 130. The drum frame may directly support the drum shaft.

[0145] The side cover 130 holds one end of the developing frame 110 in the second direction and one end of the drum frame 120 in the second direction. More specifically, the side cover 130 is fixed to one end of the drum frame 120 in the second direction. The side cover 130 has holes 131 into which the bosses 111 of the developing frame 110 are inserted. The side cover 130 rotatably supports the developing frame 110. The charging electrode 91, the drum electrode 92, the cartridge memory M, and the cartridge electrode 200 are located on the side cover 130.

[0146] 12 , the cover 140 holds the other end of the developing frame 110 in the second direction and the other end of the drum frame 120 in the second direction. More specifically, the cover 140 is fixed to the other end of the drum frame 120 in the second direction. The cover 140 supports the developing frame 110 so that it can rotate.

[0147] 13( a) and 13(b), the cartridge electrode 200 is an electrode that is electrically connected to the first drawer electrode 73 and the second drawer electrode 74. The cartridge electrode 200 has a one-end contact 210, an other-end contact 220, an electrode body 230, a one-end engaging portion 240, and an other-end engaging portion 250.

[0148] The one-end contact 210 is a portion that comes into contact with another electrode located on one side in the first direction of the cartridge electrode 200. The one-end contact 210 has a curved surface that is convex toward one side in the first direction.

[0149] The one-end contact 210 is located at one end of the cartridge frame 100 in the first direction. More specifically, the one-end contact 210 is located at one end of the side cover 130 in the first direction. The one-end contact 210 is exposed from the surface of the side cover 130 on one end side in the first direction. The one-end contact 210 is movable in the first direction. A length L1 of the one-end contact 210 in the second direction is smaller than a length L2 of the other-end contact 220 in the second direction (see also FIG. 19(b)).

[0150] The other end contact 220 is a portion that comes into contact with another electrode located on the other side in the first direction of the cartridge electrode 200. The other end contact 220 has a plane that is perpendicular to the first direction.

[0151] The other end contact 220 is located at the other end in the first direction of the cartridge frame 100. More specifically, the other end contact 220 is located at the other end in the first direction of the side cover 130. The other end contact 220 is exposed from the surface of the side cover 130 on the other end side in the first direction.

[0152] The electrode body 230 extends from the one-end contact 210 to the other-end contact 220. The electrode body 230 has an elastic portion 231, a first portion 232, a second portion 233, and a third portion 234. The elastic portion 231, the one-end contact 210, and the one-end engaging portion 240 have the same length in the second direction. The first portion 232, the second portion 233, the third portion 234, the other-end contact 220, and the other-end engaging portion 250 have the same length in the second direction.

[0153] The elastic portion 231 extends from one end of the one-end contact 210 in the third direction to the other end in the first direction, and then extends toward one side in the third direction. The elastic portion 231 is elastically deformable in the first direction. The elastic portion 231 biases the one-end contact 210 toward another electrode located on one side of the cartridge electrode 200 in the first direction.

[0154] The first portion 232 curves from one end of the elastic portion 231 in the third direction toward the other side of the first direction, and then extends toward the other side of the first direction. The second portion 233 extends from the other end of the first portion 232 in the first direction toward the other side of the third direction. The third portion 234 extends from the other end of the second portion 233 in the third direction toward the other side of the first direction, and then extends obliquely toward the other side of the first direction and the other side of the third direction and is connected to the other end contact 220.

[0155] The third portion 234 has an inclined surface 260. The inclined surface 260 is inclined with respect to the first direction. The inclined surface 260 is located at the other end of the cartridge frame 100 in the first direction. More specifically, the inclined surface 260 is located at the other end of the side cover 130 in the first direction.

[0156] 13(b) and 19(b), the length L2 of the inclined surface 260 in the second direction is greater than the length L1 of the one-end contact 210 in the second direction. The inclined surface 260 is located at the same position in the second direction as the other-end contact 220. The inclined surface 260 is located on one side in the third direction relative to the other-end contact 220. In other words, the inclined surface 260 is located upstream of the other-end contact 220 in the mounting direction of the cartridge 4.

[0157] 13A and 13B, the one-end engaging portion 240 is a portion that hooks onto one end in the first direction of the side cover 130. The one-end engaging portion 240 extends from the other end in the third direction of the one-end contact 210 in the other direction in the first direction, and then extends toward the other side in the third direction.

[0158] The other-end engaging portion 250 is a portion that catches on the other end in the first direction of the side cover 130. The other-end engaging portion 250 extends obliquely from the other end in the third direction of the other-end contact 220 toward one side in the first direction and the other side in the third direction, then extends toward one side in the first direction, and then extends toward one side in the third direction.

[0159] 13A, the side cover 130 further includes a drum bearing 132, a drum wiring 133, and a charging wiring 134. The drum bearing 132 is conductive. The drum wiring 133 connects the drum bearing 132 and the drum electrode 92. The charging wiring 134 connects the charging roller 42 and the charging electrode 91.

[0160] The cartridge electrode 200 has a shape that bypasses the drum wiring 133 and the charging wiring 134 so as not to be electrically connected to the photosensitive drum 41 and the charging roller 42. In other words, the drum wiring 133 and the charging wiring 134 are disposed inside the U-shaped portion formed by the elastic portion 231, the first portion 232, and the second portion 233 of the cartridge electrode 200.

[0161] As shown in Figure 14(a), the first cartridge 4A has a first cartridge electrode 200A. The second cartridge 4B has a second cartridge electrode 200B. The third cartridge 4C has a third cartridge electrode 200C. The fourth cartridge 4D has a fourth cartridge electrode 200D.

[0162] The contact state of each electrode when all four cartridges 4 are attached to the drawer 3 will be described below. The first drawer contact 73A of the first drawer electrode 73 contacts the first one-end contact 210A. The first other-end contact 220A contacts the second one-end contact 210B. The second other-end contact 220B contacts the third one-end contact 210C. The third other-end contact 220C contacts the fourth one-end contact 210D. The fourth other-end contact 220D contacts the second drawer contact 74A of the second drawer electrode 74.

[0163] As a result, the first drawer contact 73A of the first drawer electrode 73 is electrically connected to the first one-end contact 210A. The first other-end contact 220A is electrically connected to the second one-end contact 210B. The second other-end contact 220B is electrically connected to the second drawer contact 74A of the second drawer electrode 74 via the third cartridge electrode 200C and the fourth cartridge electrode 200D. The elastic member 77 is electrically connected to the cartridge electrode 200 via the second drawer electrode 74.

[0164] The first elastic portion 231A of the first cartridge electrode 200A biases the first one-end contact 210A toward the first drawer electrode 73. The second elastic portion 231B of the second cartridge electrode 200B biases the second one-end contact 210B toward the first other-end contact 220A. The second elastic portion 231B biases the first cartridge 4A in one of the first directions.

[0165] The third elastic portion 231C of the third cartridge electrode 200C biases the third one-end contact 210C toward the second other-end contact 220B. The third elastic portion 231C biases the second cartridge 4B in one direction in the first direction.

[0166] The fourth elastic portion 231D of the fourth cartridge electrode 200D biases the fourth one-end contact 210D toward the third other-end contact 220C. The fourth elastic portion 231D biases the third cartridge 4C in one direction in the first direction.

[0167] The elastic portion 74B of the second drawer electrode 74 urges the second drawer contact 74A toward the fourth other end contact 220D. The elastic portion 74B of the second drawer electrode 74 urges the fourth cartridge 4D in one direction in the first direction.

[0168] The first drawer electrode 73, each cartridge electrode 200, the second drawer electrode 74, the elastic member 77, and the pressing lever 76 constitute one electric circuit 7. The electric circuit 7 also includes the first body electrode 71 shown in Fig. 4, the second body electrode 72 shown in Fig. 5, and the connector 75 shown in Fig. 6, which are described above.

[0169] The control unit 6 has a function of determining whether all cartridges 4 are installed in the drawer 3 based on the current flow state of the electric circuit 7. More specifically, the control unit 6 makes this determination by applying a voltage to the electric circuit 7 and detecting the current in the electric circuit 7 with a sensor. If the control unit 6 determines, based on information from the sensor, that a current is flowing in the electric circuit 7, it determines that all cartridges 4 are installed in the drawer 3. If the control unit 6 determines, based on information from the sensor, that a current is not flowing in the electric circuit 7, it determines that at least one cartridge 4 is not installed in the drawer 3.

[0170] As shown in Figures 14(b) and 11, the side cover 130 has a first protrusion C1 and a second protrusion C2. The first protrusion C1 is a pillar having a rectangular cross section taken along a plane perpendicular to the third direction. The first protrusion C1 protrudes toward the other side of the third direction. The first protrusion C1 has a first surface C11, a second surface C12, a third surface C13, and a fourth surface C14.

[0171] The first surface C11 and the second surface C12 are surfaces perpendicular to the first direction. The first surface C11 is located at one end of the first protrusion C1 in the first direction. The second surface C12 is located at the other end of the first protrusion C1 in the first direction.

[0172] The third surface C13 and the fourth surface C14 are surfaces perpendicular to the second direction. The third surface C13 and the fourth surface C14 connect the first surface C11 and the second surface C12. The third surface C13 is located at one end of the first protrusion C1 in the second direction. The fourth surface C14 is located at the other end of the first protrusion C1 in the second direction.

[0173] The length of the first convex portion C1 in the third direction is greater than the diameter of the developing roller 43. The length of the first convex portion C1 in the third direction is greater than the diameter of the photosensitive drum 41. As shown in Figure 14 (a) , the first convex portion C1 is located between the one end contact 210 and the other end contact 220 in the first direction.

[0174] As shown in Fig. 14(b), the second protrusion C2 protrudes toward the other side in the third direction. The second protrusion C2 has the drum bearing 132 shown in Fig. 13 described above. The second protrusion C2 has a cylindrical surface C21 centered on an axis along the second direction. The second protrusion C2 is located on one side in the first direction with respect to the first protrusion C1.

[0175] The fourth wall 34 of the drawer frame 30 has a first recess H1 and a second recess H2. The first recess H1 and the second recess H2 are aligned with a gap in the first direction.

[0176] The first recess H1 is recessed toward the other side of the third direction. The first protrusion C1 of the side cover 130 fits into the first recess H1. The first recess H1 has a bottom surface H11, a first surface H12, a second surface H13, and an inclined surface H14. The bottom surface H11, the first surface H12, the second surface H13, and the inclined surface H14 are all flat surfaces.

[0177] The bottom surface H11 is located at the other end of the first recess H1 in the third direction. The first surface H12 extends from one end of the bottom surface H11 in the first direction toward one end of the third direction. The second surface H13 extends from the other end of the bottom surface H11 in the first direction toward one end of the third direction.

[0178] The inclined surface H14 is a surface that can guide the first convex portion C1 toward the bottom surface H11. The inclined surface H14 is inclined with respect to the first direction. The inclined surface H14 extends from one end of the first surface H12 in the third direction toward one side in the first direction and one side in the third direction.

[0179] The first surface H12 of the first recess H1 can come into contact with the first surface C11 of the first protrusion C1. The second surface H13 of the first recess H1 can come into contact with the second surface C12 of the first protrusion C1. When the cartridge 4 is attached to the drawer 3, the first protrusion C1 is spaced apart from the bottom surface H11 of the first recess H1.

[0180] The second recess H2 is recessed in the other direction in the third direction. The second protrusion C2 of the side cover 130 fits into the second recess H2. The second recess H2 has a bottom surface H21, a first surface H22, and a second surface H23.

[0181] The bottom surface H21 is located at the other end of the second recess H2 in the third direction. The first surface H22 extends from one end of the bottom surface H21 in the first direction toward one side in the third direction and one side in the first direction. The first surface H22 is inclined with respect to the first direction. The second surface H23 extends from the other end of the bottom surface H21 in the first direction toward one side in the third direction and the other side in the first direction. The second surface H23 is inclined with respect to the first direction.

[0182] When the cartridge 4 is attached to the drawer 3, the first surface H22 and the second surface H23 contact the cylindrical surface C21 of the second protrusion C2. When the cartridge 4 is attached to the drawer 3, the second protrusion C2 is spaced apart from the bottom surface H21 of the second recess H2.

[0183] The length L3 of the first recess H1 in the first direction is smaller than the length L4 of the second recess H2 in the first direction. As shown in Figure 14(a) , the rotation axis X6 of the developing frame 110 is located between the first recess H1 and the second recess H2 in the first direction. In the third direction, the bottom surface H11 of the first recess H1 is closer to the rotation axis X6 than the bottom surface H21 of the second recess H2.

[0184] The first recesses H1 are disposed at positions corresponding to the first protrusions C1 of each cartridge 4. The second recesses H2 are disposed at positions corresponding to the second protrusions C2 of each cartridge 4. In other words, the fourth wall 34 of the drawer frame 30 has four first recesses H1 and four second recesses H2.

[0185] 15(b) and 12, the cover 140 has a third protrusion C3 and a fourth protrusion C4. The third protrusion C3 protrudes toward the other side of the second direction. The third protrusion C3 has a cylindrical surface C31 whose center is an axis along the second direction. The cylindrical surface C31 extends in the second direction.

[0186] The fourth convex portion C4 protrudes toward the other side of the third direction. The fourth convex portion C4 has a cylindrical surface C41 whose center is along an axis extending in the second direction. The fourth convex portion C4 rotatably supports the drum coupling CP2. When projected in the second direction, the cylindrical surface C41 of the fourth convex portion C4 coincides with the cylindrical surface C21 of the second convex portion C2. In other words, the centers of the cylindrical surfaces C41 and C21 are the same, and the radii of the cylindrical surfaces C41 and C21 are the same.

[0187] 15B, the fifth wall 35 of the drawer frame 30 has a third recess H3 and a fourth recess H4. The third recess H3 and the fourth recess H4 are aligned with an interval in the first direction.

[0188] The third recess H3 is recessed toward the other side of the third direction. The third protrusion C3 of the cover 140 fits into the third recess H3. The third recess H3 has a bottom surface H31, a first surface H32, a second surface H33, a third surface H34, a fourth surface H35, and an inclined surface H36.

[0189] The bottom surface H31 is located at the other end of the third recess H3 in the third direction. The first surface H32 extends from one end of the bottom surface H31 in the first direction toward one end in the third direction and one end in the first direction. The first surface H32 is inclined with respect to the first direction. The second surface H33 extends from one end of the first surface H32 in the first direction toward one end in the third direction.

[0190] The third surface H34 extends from the other end of the bottom surface H31 in the first direction toward one side in the third direction and the other side in the first direction. The third surface H34 is inclined with respect to the first direction. The fourth surface H35 extends from the other end of the third surface H34 in the first direction toward one side in the third direction.

[0191] The inclined surface H36 is a surface that can guide the third convex portion C3 toward the bottom surface H31. The inclined surface H36 is inclined with respect to the first direction. The inclined surface H36 extends from one end of the second surface H33 in the third direction toward one end in the first direction and one end in the third direction. The inclined surface H36 is inclined with respect to the first direction.

[0192] When the cartridge 4 is attached to the drawer 3, the cylindrical surface C31 of the third protrusion C3 contacts the third recess H3. More specifically, the cylindrical surface C31 contacts the first surface H32 and the third surface H34.

[0193] 16(a) to 16(c), a portion of the first protrusion C1 and a portion of the third protrusion C3 are located at the same position in the first direction. As shown in Figs. 16(a) to 16(c), the length L5 of the third protrusion C3 in the second direction is greater than the length L6 of the first protrusion C1 in the second direction.

[0194] 15B, the fourth recess H4 is recessed in the other direction in the third direction. The fourth protrusion C4 of the cover 140 fits into the fourth recess H4. The fourth recess H4 has a bottom surface H41, a first surface H42, and a second surface H43.

[0195] The bottom surface H41 is located at the other end of the fourth recess H4 in the third direction. The first surface H42 extends from one end of the bottom surface H41 in the first direction toward one side in the third direction and one side in the first direction. The first surface H42 is inclined with respect to the first direction. The second surface H43 extends from the other end of the bottom surface H41 in the first direction toward one side in the third direction and the other side in the first direction. The second surface H43 is inclined with respect to the first direction.

[0196] When the cartridge 4 is attached to the drawer 3, the first surface H42 and the second surface H43 contact the cylindrical surface C41 of the fourth protrusion C4. When the cartridge 4 is attached to the drawer 3, the fourth protrusion C4 is spaced apart from the bottom surface H41 of the fourth recess H4.

[0197] The second recess H2 and the fourth recess H4 position the cartridge 4 in the first and third directions. The first recess H1 and the third recess H3 position the cartridge 4 by restricting the cartridge 4 supported by the second recess H2 and the fourth recess H4 from rotating about the central axis of the cylindrical surface C41.

[0198] 15A, the third recesses H3 are disposed at positions corresponding to the third protrusions C3 of each cartridge 4. The fourth recesses H4 are disposed at positions corresponding to the fourth protrusions C4 of each cartridge 4. In other words, the fifth wall 35 of the drawer frame 30 has four third recesses H3 and four fourth recesses H4.

[0199] When each cartridge 4 is attached to the drawer 3, the pressing protrusion 38 of the drawer 3 is located at a position different from the developing coupling CP1 and the drum coupling CP2 in the third direction. More specifically, the pressing protrusion 38 is located between the developing coupling CP1 and the drum coupling CP2 in the third direction.

[0200] The main body casing 2 has cartridge pressing portions 26 that press the cartridges 4 in the other of the third directions. The cartridge pressing portions 26 are disposed at positions corresponding to the respective cartridges 4. In other words, the main body casing 2 has four cartridge pressing portions 26. The cartridge pressing portions 26 may be springs, mechanisms having a spring, or cams that are rotated by a motor.

[0201] The cover 140 of the cartridge 4 has a contact portion 141 that comes into contact with the cartridge pressing portion 26. The contact portion 141 is located between the third recess H3 and the fourth recess H4 in the first direction. As shown in Fig. 12, the contact portion 141 protrudes in one direction in the third direction.

[0202] 17, the fourth wall 34 of the drawer frame 30 has four guide surfaces G1 (see also FIG. 6). The guide surfaces G1 are surfaces that guide the cartridge 4 in the third direction. The guide surfaces G1 are capable of contacting the first protrusion C1 of the cartridge 4.

[0203] The guide surface G1 is disposed at a position corresponding to the first protrusion C1 of each cartridge 4. More specifically, the guide surface G1 is located at one end in the third direction of the second surface H13 of the first recess H1. The guide surface G1 and the second surface H13 are flush with each other.

[0204] 18A and 18B, the second surface C12 of the side cover 130 is a guided surface that comes into contact with the guide surface G1 and is guided by the guide surface G1. The second surface C12 is located downstream of the other end contact 220 in the mounting direction of the cartridge 4.

[0205] As shown in Figure 18(a) , the developing frame 110 has an inclined surface F1. When the cartridge 4 is attached to the drawer 3, the inclined surface F1 is inclined with respect to the first direction. The inclined surface F1 is located at the other end of the cartridge frame 100 in the first direction. More specifically, the inclined surface F1 is located at the other end of the developing frame 110 in the first direction.

[0206] The inclined surface F1 is located on one side in the third direction with respect to the other end contact 220. In other words, the inclined surface F1 is located upstream in the mounting direction of the cartridge 4 with respect to the other end contact 220. The inclined surface F1 is located upstream in the mounting direction of the cartridge 4 with respect to the inclined surface 260 of the cartridge electrode 200.

[0207] 19( a), the length L7 of the inclined surface F1 in the second direction is greater than the length L1 of the one-end contact 210 in the second direction. As shown in Fig. 19( b), the length L7 of the inclined surface F1 in the second direction is greater than the length L2 of the other-end contact 220. A portion of the inclined surface F1 is located at the same position as the other-end contact 220 in the second direction.

[0208] 20A and 20B, the main body housing 2 has a boss B1. More specifically, the side frame 22 that supports the belt unit 5 has the boss B1. The boss B1 extends in the second direction.

[0209] The drawer frame 30 has a recess H5. The recess H5 is located at the other end of the drawer frame 30 in the first direction. The recess H5 is recessed toward one side in the first direction. When the drawer 3 is in the attached position, the boss B1 fits into the recess H5.

[0210] As shown in Figure 4, the main body housing 2 has two of the bosses B1 described above. Specifically, the side frame 23 on the other side in the second direction has a boss B1 similar to the boss B1 on the side frame 22 on one side in the second direction. The two bosses B1 are spaced apart in the second direction. The two bosses are located at the same position in the first and third directions.

[0211] As shown in Figure 6, the drawer frame 30 has two of the recesses H5 described above. One of the two recesses H5 is located at the other end in the first direction of the fourth wall 34 of the drawer frame 30. The other recess H5 is located at the other end in the first direction of the fifth wall 35 of the drawer frame 30. The two recesses H5 are spaced apart in the second direction. When the drawer 3 is in the attached position, each boss B1 shown in Figure 4 fits into the corresponding recess H5.

[0212] 21A and 21B, each of the side frames 22 and 23 has a main body side protrusion B2 that protrudes in one direction in the third direction.

[0213] The fourth wall 34 and the fifth wall 35 of the drawer frame 30 each have a drawer-side protrusion B3. The drawer-side protrusion B3 protrudes toward the other side of the third direction. The drawer-side protrusion B3 is located on one end of the drawer frame 30 in the first direction. When the drawer 3 is in the attached position, each main body-side protrusion B2 comes into contact with the corresponding drawer-side protrusion B3.

[0214] Each boss B1 and each main body-side protrusion B2 supports the drawer 3 from the other side in the third direction. The drawer 3 is positioned relative to the main body housing 2 in the third direction by each boss B1 fitting into the corresponding recess H5 and each main body-side protrusion B2 contacting the corresponding drawer-side protrusion B3.

[0215] 22(a), the main body housing 2 has a guide surface G2 and a recessed portion H6. The guide surface G2 and the recessed portion H6 are provided on each of the two side frames 22, 23. In the following explanation, the guide surface G2 and the recessed portion H6 of the side frame 22 will be explained as a representative example, and the guide surface G2 and the recessed portion H6 of the side frame 23 will not be explained because they have the same structure.

[0216] The guide surface G2 is a surface that guides the drawer 3. As shown in Fig. 22(b), the guide surface G2 has a first guide surface G21, a second guide surface G22, and a connecting surface G23. The first guide surface G21 and the second guide surface G22 extend along the first direction.

[0217] The first guide surface G21 is located at one end in the first direction of the side frame 22. The first guide surface G21 comes into contact with the base portion 37A of the guide rail 37 of the drawer 3 when the drawer 3 is located between the pulled-out position and a position just before the attached position.

[0218] The second guide surface G22 is located on the other side in the first direction and on the other side in the third direction than the first guide surface G21. As shown in Figure 22(c) , the second guide surface G22 comes into contact with the protrusion 37B of the guide rail 37 when the drawer 3 is located between the pulled-out position and a position just before the attached position.

[0219] The connecting surface G23 is connected to the other end of the first guide surface G21 in the first direction and one end of the second guide surface G22 in the first direction. The connecting surface G23 extends from the other end of the first guide surface G21 in the first direction toward the other end of the third direction and the other end of the first direction. The connecting surface G23 is inclined with respect to the first direction.

[0220] 23(c), the recess H6 is recessed from the second guide surface G22 toward the other end in the third direction. The recess H6 is located at the other end of the second guide surface G22 in the first direction. The recess H6 has a bottom surface H61, an inclined surface H62, and a vertical surface H63.

[0221] The bottom surface H61 is located at the other end of the recess H6 in the third direction. The inclined surface H62 extends from one end of the bottom surface H61 in the first direction toward one end in the third direction and one end in the first direction. In other words, the inclined surface H62 extends upstream in the installation direction of the drawer 3 and toward one end in the third direction. The inclined surface H62 is inclined with respect to the first direction.

[0222] The vertical surface H63 extends from the other end of the bottom surface H61 in the first direction toward one end in the third direction. The vertical surface H63 is perpendicular to the first direction.

[0223] When the drawer 3 is in the mounted position shown in Fig. 23(a), the convex portion 37B of the guide rail 37 fits into the concave portion H6, as shown in Fig. 23(c). When the drawer 3 is in the mounted position, the convex portion 37B contacts a surface of the main housing 2 that is flush with the vertical surface H63. Here, the surface of the main housing 2 that contacts the convex portion 37B is located at one end of the vertical surface H63 in the third direction. When the drawer 3 is in the mounted position, the convex portion 37B is spaced apart from the bottom surface H61 and the inclined surface 62.

[0224] 23(b), when the drawer 3 is in the mounted position, the base portion 37A of the guide rail 37 is located on the other side of the first guide surface G21 in the first direction. When the drawer 3 is in the mounted position, the base portion 37A is spaced apart from the second guide surface G22.

[0225] The length of the guide rail 37 in the first direction is approximately the same as the distance in the first direction from the first guide surface G21 to the recess H6. Specifically, the distance in the first direction from one end of the base 37A in the first direction to the other end of the protrusion 37B in the third direction, i.e., the point of contact of the protrusion 37B with the second guide surface G22, is approximately the same as the distance in the first direction from one end of the coupling surface G23 in the first direction to one end of the inclined surface H62 of the recess H6. As a result, when the drawer 3 is moved toward the mounting position, the timing at which the protrusion 37B contacts the inclined surface H62 and the timing at which one end of the base 37A in the first direction contacts the coupling surface G23 are approximately the same.

[0226] In the initial stage of moving the drawer 3 from the pulled-out position to the attached position, the base 37A is supported by the first guide surface G21 and the convex portion 37B is supported by the second guide surface G22, causing the drawer 3 to move along the first direction. After one end of the base 37A in the first direction reaches the connecting surface G23 and the convex portion 37B reaches the inclined surface H62, the drawer 3 moves by its own weight in a direction oblique to the first direction, toward the other side of the third direction and the other side of the first direction.

[0227] As the drawer 3 moves diagonally relative to the first direction, the inner surface of the recess H5 of the drawer 3 comes into contact with the boss B1, and the drawer-side protrusion B3 comes into contact with the main body-side protrusion B2, as shown in Fig. 21 . In other words, as the drawer 3 moves diagonally relative to the first direction, the portion of the main body housing 2 that supports the drawer 3 changes from the coupling surface G23 and the inclined surface H62 to the boss B1 and the main body-side protrusion B2. As a result, as shown in Figs. 23(b) and 23(c), the base portion 37A is maintained at a position away from the second guide surface G22, and the protrusion 37B is maintained at a position away from the bottom surface H61.

[0228] When the drawer 3 is further moved in the other direction in the first direction, the protrusion 37B comes into contact with a surface flush with the vertical surface H63, thereby positioning the drawer 3 relative to the main housing 2 in the first direction and positioning the drawer 3 in the attached position.

[0229] 23(a), 23(b), and 7, the drawer frame 30 has bosses B4. The bosses B4 are provided on both the fourth wall 34 and the fifth wall 35. In the following explanation, the boss B4 on the fourth wall 34 will be described as a representative example, and the boss B4 on the fifth wall 35 will not be described because it has a similar structure.

[0230] The boss B4 is located at one end in the first direction of the side surface 34A of the fourth wall 34. The boss B4 protrudes from the side surface 34A. The boss B4 is located at a position different from the guide rail 37 in the first direction and the third direction.

[0231] Specifically, the boss B4 is located on one side in the first direction relative to the guide rail 37. A portion of the boss B4 is located on one side in the third direction relative to the guide rail 37. Note that the entire boss B4 may be located on one side in the third direction relative to the guide rail 37.

[0232] 23(b), the main body housing 2 has a drawer pressing portion 27 that presses the boss B4 toward the other side in the third direction. The drawer pressing portion 27 is located on one side in the third direction with respect to the boss B4. The drawer pressing portion 27 may be a spring, a mechanism having a spring, or a cam that rotates by a motor.

[0233] 24(a) to 24(c), the side frame 23 has a guide surface G3 that guides the pressing protrusion 38 (see also FIG. 6) of the drawer 3. The guide surface G3 has a first guide surface G31, a second guide surface G32, and a cam surface G33.

[0234] The first guide surface G31 and the second guide surface G32 extend along the first direction. The second guide surface G32 is located on the other side of the first guide surface G31 in the first direction and on one side of the second direction.

[0235] The cam surface G33 is a surface that presses the pressing protrusion 38 in one direction in the second direction. The cam surface G33 extends obliquely from the other end of the first guide surface G31 in the first direction toward one end in the second direction and the other end in the first direction, and is connected to the second guide surface G32.

[0236] The following describes the functions of each part of the image forming apparatus 1 in various situations. When installing the second cartridge 4B in the drawer 3 in which three cartridges 4 other than the second cartridge 4B are installed as shown in Fig. 17, the user slides the one-end contact 210 of the cartridge electrode 200 of the second cartridge 4B along the inclined surface F1 of the first cartridge 4A, as shown in Fig. 18(a).

[0237] 18(b), when the first convex portion C1 of the second cartridge 4B comes into contact with the guide surface G1, the first convex portion C1 is guided toward the first concave portion H1. Then, as shown in FIGS. 14 and 15, the first convex portion C1, the second convex portion C2, the third convex portion C3, and the fourth convex portion C4 of the second cartridge 4B enter the first concave portion H1, the second concave portion H2, the third concave portion H3, and the fourth concave portion H4, thereby attaching the second cartridge 4B to the drawer 3.

[0238] As shown in Fig. 22 , when the drawer 3 is moved from the pulled-out position to the mounted position, the drawer 3 moves along the first direction while being supported by the guide surface G2, and then moves diagonally toward the other side of the third direction and the other side of the first direction. The diagonally moving drawer 3 is supported by the boss B1 and the main body-side protrusion B2 shown in Fig. 21 and positioned in the vertical direction. Then, as shown in Fig. 23 , the drawer 3 moves further, and the protrusion 37B comes into contact with a surface flush with the vertical surface H63, stopping the movement of the drawer 3 and positioning the drawer 3 in the first direction relative to the main body housing 2.

[0239] 9(a) to 9(c), when the drawer 3 moves from the pulled-out position to the attached position, the pressing lever 76 rotates, contracting the elastic member 77. As a result, the pressing lever 76 is pressed against and contacts the second body electrode 72, and one end of the drawer 3 in the first direction is pressed against the boss B1. The other end of the drawer 3 in the first direction is pressed by the drawer pressing portion 27 shown in FIG. 23(b), and is thereby pressed against the main body-side protrusion B2 shown in FIG.

[0240] 24(a) to 24(c), when the drawer 3 moves from the pulled-out position to the attached position, the pressing protrusion 38 is pushed toward one side in the second direction by the cam surface G33, and is thereby pushed into the second wall 32. Then, the spring between the pressing protrusion 38 and the second wall 32 contracts, and the spring biases the other end of the drawer 3 in the first direction toward one side in the second direction.

[0241] When the user moves the drawer 3 to the attached position and then closes the main body cover 21, the development joints J1, drum joints J2, and first main body electrode 71 shown in Fig. 4 move to one side in the second direction. As a result, the first main body electrode 71 contacts the connector 75 of the drawer 3 shown in Fig. 6 and presses one end of the drawer 3 in the first direction to one side in the second direction. As a result, one and the other ends of the drawer 3 in the first direction are pressed to one side in the second direction by the first main body electrode 71 and the pressing protrusion 38, so that the terminal 33A of the drawer 3 is pressed against and comes into contact with the main body memory electrode 85 shown in Fig. 5.

[0242] Each development joint J1 and each drum joint J2 is connected to a corresponding development coupling CP1 or drum coupling CP2. Each development joint J1 and each drum joint J2 presses the corresponding cartridge 4 toward one side in the second direction. As a result, the electrodes (91 to 95) of the cartridge 4 shown in FIG. 10 are pressed against and come into contact with the electrodes (81 to 85) shown in FIG. 5(a).

[0243] 15, when the drawer 3 is in the mounted position, each cartridge pressing portion 26 presses the corresponding cartridge 4 in the other direction in the third direction, thereby pressing each cartridge 4 against the third recess H3, the fourth recess H4, and the second recess H2 shown in FIG.

[0244] As described above, this embodiment provides the following advantages: As shown in Fig. 14, the first protrusion C1 of the side cover 130 having the cartridge electrodes 200 fits into the first recess H1 of the drawer frame 30, improving the positional accuracy of the first cartridge electrode 200A relative to the first drawer electrode 73 and the positional accuracy of the fourth cartridge electrode 200D relative to the second drawer electrode 74.

[0245] Since the second protrusion C2 of the cartridge frame 100 fits into the second recess H2 of the drawer frame 30, the cartridge 4 can be positioned with high precision relative to the drawer frame 30.

[0246] As shown in FIG. 15, the third protrusion C3 of the cover 140 fits into the third recess H3 of the drawer frame 30, so that the cartridge 4 can be positioned with precision relative to the drawer frame 30.

[0247] As shown in Figure 9, when the drawer 3 is attached, the elastic member 77 of the drawer 3 presses the drawer 3 against the main body housing 2, so the size of the image forming device 1 can be reduced compared to a configuration that includes, for example, a linkage mechanism that links a pressing member that presses the drawer with the main body cover.

[0248] As shown in Fig. 15, the pressing protrusion 38 is located between the development coupling CP1 and the drum coupling CP2 in the third direction, and therefore, when the drawer 3 moves, the pressing protrusion 38 passes between the development joint J1 and the drum joint J2 in the third direction, as shown in Fig. 25. Therefore, when the drawer 3 moves, the pressing protrusion 38 can be prevented from coming into contact with the development joint J1 or the drum joint J2.

[0249] The position of the pressing protrusion 38 may be any position as long as it is different from the positions of the development coupling CP1 and the drum coupling CP2 in the third direction. For example, as shown in Figures 25 and 26, the pressing protrusion 381 may be located on one side of the development joint J1 and the drum joint J2 in the third direction. In this case, although not shown in the figures, the pressing protrusion 381 is located on one side of the development coupling CP1 and the drum coupling CP2 in the third direction.

[0250] As shown in FIG. 20, the boss B1 of the main body housing 2 fits into the recess H5 of the drawer frame 30, so that the drawer 3 can be positioned with respect to the main body housing 2 with high precision.

[0251] The side frames 22 and 23 that support the belt unit 5 have bosses B1 for positioning the drawer 3, so that the drawer 3 can be positioned with respect to the belt unit 5 with high precision.

[0252] As shown in FIGS. 21A and 21B, the main body side protrusions B2 come into contact with the drawer side protrusions B3, so that the drawer 3 can be positioned with high precision relative to the side frames 22 and 23.

[0253] As shown in Figure 23 (c), the recess H6 of the main housing 2 has an inclined surface H62, so that when the drawer 3 is pulled out from the main housing 2, the protrusion 37B of the drawer 3 slides along the inclined surface H62, allowing the drawer 3 to be pulled out smoothly.

[0254] 4, the first drawer electrode 73, each cartridge electrode 200, and the second drawer electrode 74 shown in Fig. 14, and the second body contact 72A shown in Fig. 5 are electrically connected, thereby forming an electric circuit 7 that passes current from the first body contact 71A to the second body contact 72A via the first drawer electrode 73, each cartridge electrode 200, and the second drawer electrode 74. Therefore, it is possible to provide an image forming apparatus 1 that has a new electric circuit 7 that passes through the main body housing 2, the drawer 3, and the cartridge 4.

[0255] The present disclosure is not limited to the above-described embodiment, but can be used in various forms as exemplified below. In the following description, members having substantially the same structure as those in the above-described embodiment are denoted by the same reference numerals, and their description will be omitted.

[0256] The four third recesses H3 may be arranged at a constant pitch in the first direction, or may be arranged at different pitches. For example, as shown in FIG. 27A, in an A-type image forming apparatus 1, the pitches of the third recesses H3 may be P2, P3, and P4, in order from the other side in the first direction. The relationship of the pitches may be P2<P3<P4.

[0257] 27B, in the B-type image forming apparatus 1, the pitches of the third recesses H3 can be P1, P1, and P5, starting from the other side in the first direction. The relationship of the pitches can be P1<P2<P3<P4<P5. The position of the third protrusion C3 of each cartridge 4 may be set so as to fit into the corresponding third recess H3.

[0258] In this way, by setting the pitch of the four third recesses H3 to different sizes depending on the model, it is possible to prevent, for example, a type A cartridge 4 from being mistakenly installed in a type B drawer 3. It is also possible to prevent a type B cartridge 4 from being mistakenly installed in an type A drawer 3.

[0259] The second direction may be any direction that intersects with the first direction, and the third direction may be any direction that intersects with the first and second directions.

[0260] 19(b) may be equal to or shorter than the length of the one-end contact in the second direction. In this case, the entire inclined surface 260 may be located at the same position in the second direction as the other-end contact 220. The length of the one-end contact in the second direction may be equal to or longer than the length of the other-end contact in the second direction.

[0261] The electrical circuit may be used to ground the photosensitive drum, specifically, the cartridge electrodes may be connected to the photosensitive drum.

[0262] The second drawer contact may not be movable in the first direction, and the first drawer contact may be movable in the first direction. The one end contact may not be movable in the first direction, and the other end contact may be movable in the first direction.

[0263] The first protrusion does not have to have a surface perpendicular to the first direction. The first protrusion is not limited to a prismatic shape and may be, for example, a cylindrical shape. The first protrusion does not have to be located between the one end contact and the other end contact in the first direction.

[0264] The rotation axis of the developing frame relative to the drum frame does not have to be located between the first recess and the second recess in the first direction.

[0265] The length of the first recess in the first direction may be equal to or greater than the length of the second recess in the first direction. In the third direction, the bottom surface of the first recess may be farther from the pivot axis than the bottom surface of the second recess.

[0266] The third convex portion may not have a cylindrical surface. The third concave portion may not have an inclined surface. The third convex portion may not have a portion located at the same position as a part of the first convex portion in the first direction. In other words, the third convex portion may not overlap with the first convex portion when viewed from the second direction.

[0267] The length of the third protrusion in the second direction may be equal to or less than the length of the first protrusion in the second direction.

[0268] The elastic member is not limited to a torsion spring, and may be, for example, a leaf spring, a wire spring, a coil spring, etc. The elastic member and the pressing lever may be non-conductive.

[0269] The pressing lever may be omitted. In this case, the elastic member may contact the second main electrode as a conductive member. Also, the main body housing may not have a groove for receiving the pressing lever.

[0270] The side surface of the drawer frame may intersect with the second direction.

[0271] The positions and shapes of the components such as the electrodes, elastic members, pressure levers, connectors, pressure protrusions, contact portions, bosses, and recesses are not limited to those in the above-described embodiment and can be changed as appropriate.

[0272] The image forming apparatus may be a copying machine, a multifunction machine, or the like.

[0273] The elements described in the above-described embodiment and modified examples may be implemented in any combination.

[0274] REFERENCE SIGNS LIST 1 Image forming apparatus 2 Main body housing 3 Drawer 4 Cartridge 30 Drawer frame 30A Handle 41 Photosensitive drum 43 Developing roller 71A First main body contact 72A Second main body contact 73 First drawer electrode 74 Second drawer electrode 77 Elastic member 130 Side cover 200 Cartridge electrode 210A First one-end contact 210B Second one-end contact 220A First other-end contact 220B Second other-end contact 230 Electrode main body 411 Drum shaft 431 Developing shaft C1 First convex portion H1 First concave portion X1 Drum shaft X3 Developing shaft

Claims

1. An image forming apparatus comprising: a main body housing having a first main body contact and a second main body contact; a drawer movable in a first direction relative to the main body housing, the drawer having a drawer frame, a first drawer electrode electrically connected to the first main body contact, and a second drawer electrode electrically connected to the second main body contact; and a cartridge detachably attached to the drawer, the cartridge having a developing roller having a developing shaft extending in a second direction intersecting the first direction, a photosensitive drum having a drum shaft extending in the second direction, a cartridge electrode electrically connected to the first drawer electrode and the second drawer electrode, and a side cover located at one end of the developing roller in the second direction, the cartridge electrode being located, wherein the drawer frame has a first recess that is recessed in a third direction intersecting the first direction and the second direction, and the side cover has a first convex portion that protrudes in the third direction and fits into the first recess.

2. An image forming apparatus according to claim 1, wherein said first convex portion has a surface perpendicular to said first direction.

3. An image forming apparatus as described in claim 1, characterized in that the cartridge has a cartridge frame that rotatably supports the developing shaft and the drum shaft, the cartridge electrode has a one-end contact located at one end of the cartridge frame in the first direction and an other-end contact located at the other end of the cartridge frame in the first direction, and the first convex portion is located between the one-end contact and the other-end contact in the first direction.

4. The image forming apparatus described in claim 1 or claim 2, characterized in that the cartridge has a cartridge frame having a developing frame that rotatably supports the developing shaft and a drum frame that rotatably supports the drum shaft, the developing frame is rotatable relative to the drum frame around a rotation axis extending along the second direction, the drawer frame has a second recess that is recessed in the third direction, the cartridge frame has a second convex portion that protrudes in the third direction and enters the second recess, and the rotation axis is located between the first recess and the second recess in the first direction.

5. An image forming apparatus according to claim 4, wherein the length of said first recess in said first direction is smaller than the length of said second recess in said first direction.

6. The image forming apparatus according to claim 4, wherein in the third direction, the bottom surface of the first recess is closer to the rotation axis than the bottom surface of the second recess.

7. The image forming apparatus described in claim 1, characterized in that the cartridge has a cartridge frame having a developing frame that rotatably supports the developing shaft and a drum frame that rotatably supports the drum shaft, the cartridge frame has a cover that holds the developing frame and the drum frame and is located at the other end of the cartridge frame in the second direction, the drawer frame has a third recess that is recessed in the third direction, and the cover has a third convex portion that fits into the third recess.

8. An image forming apparatus according to claim 7, characterized in that the third convex portion has a cylindrical surface that contacts the third concave portion and extends in the second direction.

9. The image forming apparatus according to claim 7, wherein the third recess has an inclined surface inclined with respect to the first direction.

10. An image forming apparatus according to claim 7, wherein a portion of said first convex portion and a portion of said third convex portion are located at the same position in said first direction.

11. An image forming apparatus as described in any one of claims 7 to 10, characterized in that the length of the third convex portion in the second direction is greater than the length of the first convex portion in the second direction.

12. A device comprising: a main housing; a drawer movable in a first direction relative to the main housing between an attached position located within the main housing and a pulled-out position at least a portion of which is located outside the main housing, the drawer having a drawer frame and a handle located at one end of the drawer frame in the first direction; and a cartridge detachable from the drawer frame, the cartridge having a developing roller rotatable about a developing axis extending in a second direction intersecting the first direction, and a photosensitive drum rotatable about a drum axis extending in the second direction, the drawer further comprising: an elastic member that receives a force from the main housing when the drawer moves from the pulled-out position to the attached position, and that is displaced from a first position to a second position, the elastic member having a greater elastic force at the second position than at the first position; An image forming apparatus characterized in that, when the elastic member is displaced from the first position to the second position, the elastic member presses the main housing in one direction of a third direction intersecting the first direction and the second direction, and the drawer is pressed in the other direction of the third direction by the elastic force of the elastic member.

13. The image forming apparatus according to claim 12, wherein the elastic member is located at the other end of the drawer frame in the first direction and at one end of the drawer frame in the second direction.

14. The image forming apparatus of claim 12 or 13, characterized in that the drawer further has a pressure lever supported on the drawer frame so as to be rotatable around a rotation axis along the second direction, and the elastic member presses the main body housing via the pressure lever.

15. An image forming apparatus as described in claim 14, characterized in that the drawer frame has a boss extending in the second direction, and the pressing lever has a base end having a hole into which the boss fits, and a tip end extending from the base end and protruding from the drawer frame.

16. An image forming apparatus according to claim 12, characterized in that the main body housing has a main body electrode, the cartridge has a cartridge electrode, and the elastic member is conductive and electrically connected to the main body electrode and the cartridge electrode.

17. The image forming apparatus according to claim 14, characterized in that the main body housing has a groove extending in the first direction into which the pressure lever fits, and when the drawer is in the attached position, the elastic member presses the pressure lever against a bottom surface of the groove.

18. An image forming apparatus as described in claim 12, characterized in that the drawer frame has a pressing protrusion extending in the second direction at the other end in the first direction and the other end in the second direction, which presses the drawer toward one end in the second direction.

19. The image forming apparatus described in claim 18, characterized in that the cartridge has a development coupling that transmits a driving force to the developing roller, the development coupling being located at the other end of the cartridge in the second direction, and a drum coupling that transmits a driving force to the photosensitive drum, the drum coupling being located at the other end of the cartridge in the second direction, and the pressing protrusion is located at a position different from the development coupling and the drum coupling in the third direction.

20. The image forming apparatus according to claim 12, wherein the main body housing has a cartridge pressing portion that presses the cartridge in the third direction.

21. An image forming apparatus as described in claim 20, characterized in that the drawer frame has two recesses for positioning the cartridge, the two recesses being aligned in the first direction, the cartridge has a contact portion that contacts the cartridge pressing portion, and the contact portion is located between the two recesses in the first direction.

22. The image forming apparatus of claim 12, characterized in that the main body housing has a boss extending in the second direction, the two bosses being spaced apart in the second direction; the drawer frame has two recesses located at the other end in the first direction and spaced apart in the second direction, the two recesses being recessed in the first direction; and when the drawer is in the attached position, the bosses enter the recesses.

23. The image forming apparatus according to claim 22, further comprising a belt unit having a belt that contacts the photosensitive drum, the main body housing having a side frame that supports the belt unit, and the side frame having the boss.

24. An image forming apparatus as described in claim 23, characterized in that the side frame has a main body side convex portion protruding in one direction of the third direction, and the drawer frame has a drawer side convex portion protruding in the other direction of the third direction, and when the drawer is located in the attached position, the main body side convex portion comes into contact with the drawer side convex portion.

25. The image forming apparatus according to claim 12, characterized in that the drawer frame has a side surface that intersects with the second direction, and a guide rail that protrudes from the side surface and extends in the first direction, the guide rail being guided by the main body housing.

26. The image forming apparatus described in claim 25, characterized in that the guide rail has a convex portion located at the end in the first direction and having an R-shaped convex portion that convex toward the third direction, and the main body housing has a recess into which the convex portion fits when the drawer is located in the attached position, the recess being recessed in the third direction.

27. The image forming apparatus according to claim 26, wherein the recess has an inclined surface that is inclined toward one of the upstream side in the mounting direction of the drawer and the third direction.

28. An image forming apparatus as described in any one of claims 25 to 27, characterized in that the drawer frame is located at one end of the side surface in the first direction and has a boss protruding from the side surface, and the main body housing has a drawer pressing portion that presses the boss in the third direction.

29. The image forming apparatus according to claim 28, wherein the boss is located at a position different from the position of the guide rail in the third direction.

30. The image forming apparatus according to claim 12, wherein the cartridge is mounted to the drawer frame in the other direction of the third direction and is removed from the drawer frame in the one direction of the third direction.

31. The image forming apparatus according to claim 12, wherein the photosensitive drum is located at the other end of the cartridge in the third direction.

32. A device comprising: a main housing; a drawer movable in a first direction relative to the main housing; and a first cartridge and a second cartridge detachably attached to the drawer, the first cartridge and the second cartridge being aligned in the first direction, wherein the main housing has a first main body contact and a second main body contact, wherein the drawer has: a drawer frame; a first drawer electrode electrically connected to the first main body contact, the first drawer electrode being located at one end of the drawer frame in the first direction; and a second drawer electrode electrically connected to the second main body contact, the second drawer electrode being located at the other end of the drawer frame in the first direction, wherein the first cartridge has: a first cartridge frame; a first developing roller having a first developing shaft extending in a second direction intersecting the first direction; a first photosensitive drum having a first drum shaft extending in the second direction; and a first cartridge electrode, the first one-end contact being located at one end of the first cartridge frame in the first direction; an electrode body extending from the first one-end side contact to the first other-end side contact; and a second cartridge electrode having a first other-end side contact located at the other end of the first cartridge frame in the first direction, and a first electrode body extending from the first one-end side contact to the first other-end side contact; the second cartridge comprises: a second cartridge frame, a second developing roller having a second developing shaft extending in the second direction, a second photosensitive drum having a second drum shaft extending in the second direction, and a second cartridge electrode having a second one-end side contact located at one end of the second cartridge frame in the first direction, a second other-end side contact located at the other end of the second cartridge frame in the first direction, and a second electrode body extending from the second one-end side contact to the second other-end side contact; and the first drawer electrode is electrically connected to the first one-end side contact, the first other-end side contact is electrically connected to the second one-end side contact, and the second other-end side contact is electrically connected to the second drawer electrode.

33. The image forming apparatus according to claim 32, wherein the first end contact is movable in the first direction.

34. An image forming apparatus as described in claim 32, characterized in that the first cartridge comprises: a first developing coupling which transmits a driving force to the first developing roller; and a first drum coupling which transmits a driving force to the first photosensitive drum; the first cartridge frame has one end located at one end of the first cartridge frame in the second direction and another end located at the other end of the first cartridge frame in the second direction; the first cartridge electrode is located at the one end of the first cartridge frame; and the first developing coupling and the first drum coupling are located at the other end of the first cartridge frame.

35. An image forming apparatus according to claim 34, characterized in that said first cartridge comprises: a first developing electrode electrically connected to said first developing shaft, said first developing electrode being located at said one end of said first cartridge frame.

36. The image forming apparatus described in claim 34, characterized in that the first cartridge frame comprises: a first drum frame rotatably supporting the first drum shaft; a first developing frame rotatably supporting the first developing shaft, the first developing frame being rotatable relative to the first drum frame; and a first side cover holding the first drum frame and the first developing frame, the first side cover being located at the one end of the first cartridge frame; and the first cartridge electrode being located on the first side cover.

37. An image forming apparatus as described in claim 32, characterized in that the first cartridge has an inclined surface that is inclined with respect to the first direction, an inclined surface located at the other end of the first cartridge frame in the first direction, at least a portion of which is located at the same position as the first other end contact in the second direction, and which is located upstream of the first other end contact in the mounting direction of the first cartridge.

38. An image forming apparatus according to claim 37, wherein the length of said inclined surface in said second direction is greater than the length of said first one-end contact point in said second direction.

39. An image forming apparatus according to claim 38, wherein the length of said first one-end contact in said second direction is smaller than the length of said first other-end contact in said second direction.

40. An image forming apparatus as described in claim 32, characterized in that the first drawer electrode has a first drawer contact electrically connected to the first one-end contact, and the second drawer electrode has a second drawer contact electrically connected to the second other-end contact.

41. The image forming apparatus according to claim 40, wherein said second drawer contact is movable in said first direction.

42. An image forming apparatus as described in claim 40, characterized in that the drawer has a connector electrically connected to the first drawer electrode, the connector receiving power from the first main body contact, the drawer frame having one end located at one end of the drawer frame in the second direction and another end located at the other end of the drawer frame in the second direction, the second drawer contact located at the one end of the drawer frame, and the connector located at the other end of the drawer frame.

43. An image forming apparatus as described in claim 40, characterized in that the drawer has a conductive member electrically connected to the second drawer electrode and the second main body contact, the conductive member being located at the other end of the drawer frame in the first direction and protruding from the drawer frame in a third direction intersecting the first direction and the second direction.

44. An image forming apparatus as described in claim 43, characterized in that the drawer has a conductive spring that urges the conductive member against the second main body contact, the spring being electrically connected to the second drawer electrode and the conductive member.

45. An image forming apparatus as described in claim 40, further comprising a control unit which determines whether or not all cartridges are installed in the drawer based on the electrical current state of a circuit including the first main body contact, the first drawer electrode, the first cartridge electrode, the second cartridge electrode, the second drawer electrode and the second main body contact.

46. ​​An image forming apparatus as described in claim 40, characterized in that the drawer frame has a guide surface that guides the first cartridge in a third direction intersecting the first direction and the second direction, and the first cartridge frame has a guided surface that is guided by the guide surface by coming into contact with the guide surface, and is located downstream in the mounting direction of the cartridge from the first other end side contact point.

47. The image forming apparatus according to claim 40, wherein the drawer has a handle located at one end of the drawer frame in the first direction.

48. An image forming apparatus according to claim 40, wherein the first direction is perpendicular to the second direction.

49. An image forming apparatus according to any one of claims 32 to 48, characterized in that the second cartridge electrode has an elastic portion that urges the first cartridge in the first direction.

Images