Image forming apparatus and developing cartridge
An image forming apparatus includes a drum unit which holds plural photosensitive drums, a developing cartridge which is provided for each photosensitive drum, a translation member which is provided to be movable linearly, and a movable member for each developing cartridge. The movable member includes a main body rotatably supported by the supporting shaft at one end portion thereof, an input portion provided at the other end portion thereof and to which a pressing force is input by the translation member with the linear movement thereof; an abutting portion which is provided between the one and other end portions of the main body, and abuts the drum unit while the movable member rotates about the supporting shaft; and an operating portion which applies to the supporting shaft a force for moving the developing cartridge as the movable member is rotated with the middle portion as a fulcrum.
1. An image forming apparatus comprising:
an apparatus body;
a tandem photosensitive drum unit which holds a plurality of photosensitive drums to be in parallel with each other, and is movably mounted in the apparatus body along an array direction of the photosensitive drums;
a developing cartridge which is provided for each of the photosensitive drums, supports a developing roller for supplying developer to the corresponding photosensitive drum, and is configured to be detachably mounted in the tandem photosensitive drum unit;
a translation member which is provided in the apparatus body to be movable linearly in the array direction;
a supporting shaft which is provided on each of the developing cartridges; and
a movable member which is rotatably supported by the supporting shaft, and provided at a position where the translation member abuts along a linear movement thereof,
wherein the movable member includes:
a main body which extends in a direction orthogonal to the supporting shaft, and is rotatably supported by the supporting shaft at a first end portion of the main body in a longitudinal direction thereof;
an input portion which is provided at a second end portion of the main body opposite to the first end portion, and to which a pressing force is input by the translation member with the linear movement of the translation member after abutting the input portion;
an abutting portion which is provided at a middle portion between the first and second end portions of the main body, and abuts the tandem photosensitive drum unit while the movable member rotates about the supporting shaft by the input of the pressing force to the input portion; and
an operating portion which is configured to apply a force to the supporting shaft for moving the developing cartridge from a first position where the developing roller contacts the photosensitive drum to a second position where the developing roller is separated from the photosensitive drum as the movable member is rotated with the abutting portion as a fulcrum by the input of the pressing force to the input portion while the abutting portion abuts the tandem photosensitive drum unit.
2. The image forming apparatus according to claim 1 , wherein the abutting portion includes a boss which protrudes from the main body of the movable member in a direction parallel to the supporting shaft.
3. The image forming apparatus according to claim 1 ,
wherein the apparatus body includes a body reference shaft which extends in an axial direction of the photosensitive drum,
wherein the tandem photosensitive drum unit abuts the body reference shaft in a state where the tandem photosensitive drum unit is mounted in the apparatus body, and
wherein a direction in which the tandem photosensitive drum unit abuts the body reference shaft is substantially same as a direction of the pressing force input to the input portion of the movable member from the translation member.
4. The image forming apparatus according to claim 1 , wherein the translation member includes a cam portion which is provided for each of the movable members, and abuts the input portion of the corresponding movable member to press the input portion.
5. The image forming apparatus according to claim 4 , wherein the cam portions are arranged so as to take a first state where all the cam portions abut the input portions of the movable members, respectively, a second state where at least one of the cam portions abuts the input portion of the corresponding movable member, and a third state where all the cam portions are separated from the input portions of the movable members, respectively, according to the linear movement of the translation member.
6. The image forming apparatus according to claim 5 ,
wherein the developing cartridges correspond to colors of black, yellow, magenta, and cyan, respectively, and
wherein in the second state, one of the cam portions corresponding to the input portion of the movable member for the black is separated therefrom, and the others of the cam portions corresponding to the input portions of the movable members for the yellow, magenta, and cyan abut thereon.
7. The image forming apparatus according to claim 4 , wherein each of the cam portions has an inclined surface configured to abut the input portion of the corresponding movable member, the inclined surface being inclined with respect to an axial direction of the photosensitive drum.
8. The image forming apparatus according to claim 1 , further comprising:
a pressing mechanism which is provided for each of the developing cartridges to press the corresponding developing cartridge in a direction in which the developing roller and the photosensitive drum oppose each other in a state where the developing cartridge is mounted in the tandem photosensitive drum unit.
9. The image forming apparatus according to claim 8 ,
wherein each of the pressing mechanisms is rotatably supported by a second supporting shaft provided in the tandem photosensitive drum unit, and
wherein each of the pressing mechanisms includes:
a pressing member which abuts a pressed portion provided in the corresponding developing cartridge, and
a spring which resiliently presses the pressing member to the pressed portion of the corresponding developing cartridge.
10. The image forming apparatus according to claim 1 , wherein the movable member is provided on both sides of each developing cartridge in an axial direction of the developing roller.
11. The image forming apparatus according to claim 10 , further comprising a connecting portion which connects the input portions of the movable members together.
12. The image forming apparatus according to claim 1 , wherein the movable member is provided such that the operating portion, the abutting portion, and the input portion are arranged in order from a developing roller side in a direction in which the developing roller and the photosensitive drum oppose each other.
13. A developing cartridge configured to be detachably mountable in an apparatus body of an image forming apparatus, the developing cartridge comprising:
a developing roller which is configured to supply developer to a photosensitive drum;
a supporting shaft; and
a movable member which is rotatably supported by the supporting shaft,
wherein the movable member includes:
a main body which extends in a direction orthogonal to the supporting shaft, and is rotatably supported by the supporting shaft at a first end portion of the main body in a longitudinal direction thereof;
an input portion which is provided at a second end portion of the main body opposite to the first end portion, and to which a pressing force is input from an external member;
an abutting portion which is provided at a middle portion between the first and second end portions of the main body, and abuts a predetermined portion in the apparatus body while the movable member rotates about the supporting shaft by the input of the pressing force to the input portion; and
an operating portion which is configured to apply a force to the supporting shaft for moving the developing cartridge from a first position where the developing roller contacts the photosensitive drum to a second position where the developing roller is separated from the photosensitive drum as the movable member is rotated with the abutting portion as a fulcrum by the input of the pressing force to the input portion while the abutting portion abuts the predetermined portion.
14. The developing cartridge according to claim 13 , wherein the movable member is provided on both sides of the developing cartridge in an axial direction of the developing roller.
15. The developing cartridge according to claim 14 , further comprising a connecting portion which connects input portions of the movable members together.
16. The developing cartridge according to claim 13 , wherein the movable member is provided such that the operating portion, the abutting portion, and the input portion are arranged in order from the developing roller side in a direction in which the developing roller and the photosensitive drum oppose each other.
17. An image forming apparatus comprising:
an apparatus body;
a drum unit which holds a photosensitive drum, and is movably mounted along a first direction orthogonal to an axial direction of the photosensitive drum;
a developing cartridge which supports a developing roller for supplying developer to the photosensitive drum, and is configured to be detachably mounted in the drum unit, the developing cartridge including a supporting shaft extending along the axial direction;
a translation member in the apparatus body to be movable linearly in the first direction; and
a movable member including:
a first part provided at one end thereof, and rotatably supported by the supporting shaft;
a second part provided at the other end thereof and located at a position abuttable on the translation member moving linearly to rotate the movable member about the supporting shaft;
a middle part provided between the first part and second part, and configured to abut the drum unit when the movable member rotates by abutment between the translation member and the second part.