US 2007/0177899 A1Published application

Image forming apparatus

AssigneeCanon Kabushiki Kaisha

InventorKoji KAWAMURA

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Abstract

An image forming apparatus detachably mounts black and non-black cartridges each including a photosensitive drum and a developing roller. The apparatus includes a driving source; first and second clutches for connecting and disconnecting between the driving source and the developing roller of the black and non-black cartridges, respectively; movable first and second members actable on the first and second clutches, respectively, for switching between transmitting the driving force to the developing rollers and not transmitting the driving force; and a switching member, movable by the driving force of the driving source and actable on the first and second members for switching among first, second, and third modes for transmitting the driving force to the developing rollers of all of the cartridges, not transmitting the driving force to any one of the rollers, and transmitting the driving force only to the developing roller of the black cartridge.

Claims28

Dependent claims

An image forming apparatus for forming a color image on a recording material, comprising:

(i) mounting means for detachably mounting a plurality of process cartridges each including a photosensitive drum and a developing roller for developing an electrostatic latent image formed on said photosensitive drum, said process cartridges including a black process cartridge containing a black color developer and a non-black process cartridge containing a non-black developer;
(ii) a driving source;
(iii) a first clutch for connecting and disconnecting between said driving source and said developing roller for selective driving force transmission to the black process cartridge;
(iv) a second clutch for connecting and disconnecting between said driving source and said developing roller for selective driving force transmission to the non-black process cartridge;
(v) a movable first member actable on said first clutch for switching between an operation state for transmitting the driving force to said developing rollers and a non-operation state not transmitting the driving force thereto;
(vi) a movable second member, actable on said second clutch, for switching between an operation state for transmitting the driving force to said developing rollers and a non-operation state not transmitting the driving force thereto;
(vii) a switching member, movable by the driving force of said driving source and actable on said first member and second member, for switching among a first mode for transmitting the driving force to said developing rollers of all of said process cartridges, a second mode for not transmitting the driving force to any one of said developing rollers, and a third mode for transmitting the driving force only to said developing roller of said black process cartridge.

4 more elements

An image forming apparatus for forming a color image on a recording material, comprising:

(i) mounting means for detachably mounting a plurality of process cartridges each including a photosensitive drum, a developing roller for developing an electrostatic latent image formed on said photosensitive drum, a first frame for rotatably supporting said photosensitive drum and a second frame for rotatably supporting said developing roller, said second frame being movable relative to said first frame to contact said developing roller to said photosensitive drum and spacing said developing roller from said photosensitive drum, said process cartridges including a black process cartridge containing a black color developer and a non-black process cartridge containing a non-black developer;
(ii) a driving source;
(iii) a first clutch for connecting and disconnecting between said driving source and said developing roller for selective driving force transmission to the black process cartridge;
(iv) a second clutch for connecting and disconnecting between said driving source and said developing roller for selective driving force transmission to the non-black process cartridge;
(v) a first member for switching between an operation state for acting on said first clutch and on said second frame of said black process cartridge to contact said photosensitive drum and said developing roller to each other and transmit the driving force to said developing roller in said black process cartridge, and a non-operation state not transmitting the driving force thereto;
(vi) a second member for switching between an operation state for acting on said second clutch and on said second frame of said non-black process cartridge to contact said photosensitive drum and said developing roller to each other and transmit the driving force to said developing roller in said non-black process cartridge, and a non-operation state not transmitting the driving force thereto;
(vii) a switching member, movable by the driving force of said driving source and actable on said first member and second member, for switching among a first mode for contacting said developing rollers to said photosensitive drums, respectively and for transmitting the driving force to said developing rollers of all of said process cartridges, a second mode for spacing said developing rollers from said photosensitive drums and for not transmitting the driving force to any one of said developing rollers, and a third mode for contacting said developing roller to said photosensitive drum and for transmitting the driving force only to said developing roller of said black process cartridge.

4 more elements

An image forming apparatus for forming a color image on a recording material, comprising:

(i) mounting means for detachably mounting a plurality of process cartridges each including a photosensitive drum, a developing roller for developing an electrostatic latent image formed on said photosensitive drum, a first frame for rotatably supporting said photosensitive drum and a second frame for rotatably supporting said developing roller, said second frame being movable relative to said first frame to contact said developing roller to said photosensitive drum and spacing said developing roller from said photosensitive drum, said process cartridges including a black process cartridge containing a black color developer and a non-black process cartridge containing a non-black developer;
(ii) a driving source;
(iii) a first clutch for connecting and disconnecting between said driving source and said developing roller for selective driving force transmission to the black process cartridge;
(iv) a second clutch for connecting and disconnecting between said driving source and said developing roller for selective driving force transmission to the non-black process cartridge;
(v) a movable first member actable on said first clutch for switching between an operation state for transmitting the driving force to said developing rollers and a non-operation state not transmitting the driving force thereto;
(vi) a movable second member, actable on said second clutch, for switching between an operation state for transmitting the driving force to said developing rollers and a non-operation state not transmitting the driving force thereto;
(vii) a movable third member, actable on said second frame of said black process cartridge, for switching between an operation state for transmitting the driving force to said developing rollers and a non-operation state not transmitting the driving force thereto in said black process cartridge;
(viii) a fourth member, actable on said second frame of said non-black process cartridge, for switching between an operation state for transmitting the driving force to said developing rollers and a non-operation state not transmitting the driving force thereto in said non-black process cartridge;
and
(ix) a switching member, movable by the driving force of said driving source and actable on said first member, said second member, said third member and said fourth member, for switching among a first mode for contacting said developing rollers to said photosensitive drums, respectively and for transmitting the driving force to said developing rollers of all of said process cartridges, a second mode for spacing said developing rollers from said photosensitive drums and for not transmitting the driving force to any one of said developing rollers, and a third mode for contacting said developing roller to said photosensitive drum and for transmitting the driving force only to said developing roller of said black process cartridge.

7 more elements

Dependencies are inferred from the claim text.