Image forming apparatus featuring a constant contact-pressure drive

Claim 2

An image forming apparatus, comprising: a movable image bearing member; a rotatable member press-contacted to said image bearing member in relation to an image forming process for forming an image on said image bearing member, said rotatable member having a longitudinal shaft; driving means for driving said rotatable member; and transmission means for transmitting a driving force to the shaft of said rotatable member from said driving means, said transmission means having coupling means for transmitting a rotational force substantially without imparting to said shaft a force in a radial direction thereof.

Claim 3

An apparatus according to claim 1, wherein said rotatable member comprises elastic material.

Claim 4

An apparatus according to claim 1 or 2, wherein said rotatable member is supported for movement toward and away from said image bearing member.

Claim 5

An apparatus according to claim 3, further comprising guiding means for guiding said rotatable member toward and away from said image bearing member.

Claim 6

An apparatus according to claim 3, further comprising pressing means for press-contacting said rotatable member to said image bearing member.

Claim 7

An apparatus according to claim 5, wherein said pressing means is a spring.

Claim 8

An apparatus according to claim 3, wherein said coupling means transmits the rotational force substantially without transmitting a force in a direction of the movement toward and way from said image bearing member.

Claim 9

An apparatus according to claim 1, wherein said transmission means includes a gear for transmitting the driving force from said driving means to an upstream side of said coupling means with respect to a drive transmission direction.

Claim 10

An apparatus according to claim 1, further comprising a supporting member for fixedly supporting a shaft of said image bearing member.

Claim 11

An apparatus according to claim 1, wherein said coupling includes a projection and a groove for slidable engagement with the projection for transmitting the driving force from said driving means.

Claim 12

An apparatus according to claim 1, wherein said rotatable member is an image transfer rotatable member for transferring an image formed on said image bearing member to a transfer material.

Claim 13

An apparatus according to claim 1, wherein said rotatable member is a charging rotatable member for electrically charging said image bearing member.

Claim 14

An apparatus according to claim 1, wherein said rotatable member is a cleaning roller for removing residual matter from said image bearing member.

Claim 15

An apparatus according to claim 1, wherein said rotatable member includes a belt for press-contact to said image bearing member and a roller for urging the belt to said image bearing member.

Claim 16

An apparatus according to claim 1, wherein said coupling means includes an absorbing portion for absorbing deformation toward and away from said image bearing member, transmitted from an upstream side of said coupling means in a direction of a drive transmission.

Claim 17

An apparatus according to claim 1, 9, or 15, wherein said coupling means is slidable in the radial direction.

Claim 18

An apparatus according to claim 1, wherein said transmission means has a drive transmission member for transmitting the driving force to said shaft substantially without changing an angular speed of said drive transmission member despite movement of said shaft relative to said transmission means.

Claim 19

An image forming apparatus, comprising: a movable image bearing member; a rotatable member press-contacted to said image bearing member in relation to an image formation process for forming an image on said image bearing member, said rotatable member having a longitudinal shaft, said image bearing member being rotatably supported; driving means for driving said rotatable member; drive transmission means for transmitting driving force from said driving means coaxially with said shaft of said rotatable member, said drive transmission means having a drive transmission member rotatably supported on a shaft for transmitting the driving force to said shaft of said press-contacted rotatable member, and the drive transmitting force being transmitted to said shaft of said press-contacted rotatable member substantially without changing an angular speed of said drive transmission member despite movement of said shaft of said press-contacted rotatable member relative to said shaft of said drive transmission member.

Claim 20

An image forming apparatus, comprising: a movable image bearing member; a rotatable member press-contacted to said image bearing member in relation to an image formation process for forming an image on said image bearing member, said rotatable member having a longitudinal shaft, said image bearing member being rotatably supported; driving means for driving said rotatable member; drive transmission means for transmitting driving force from said driving means coaxially with said shaft of said rotatable member, said drive transmission means having a drive transmission member rotatably supported on a shaft for transmitting the driving force to said shaft of said press-contacted rotatable member, and the drive transmitting force being transmitted to said shaft of said press-contacted rotatable member substantially without changing an angular speed of said drive transmission member despite movement of said shaft of said press-contacted rotatable member relative to said shaft of said drive transmission member.

Claim 21

An apparatus according to claim 18, wherein said rotatable member comprises elastic material.

Claim 22

An apparatus according to claim 18 or 19, wherein said rotatable member is supported for movement toward and away from said image bearing member.

Claim 23

An apparatus according to claim 20, further comprising guiding means for guiding said rotatable member toward and away from said image bearing member.

Claim 24

An apparatus according to claim 20, further comprising pressing means for press-contacting said rotatable member to said image bearing member.

Claim 25

An apparatus according to claim 22, wherein said pressing means is a spring.

Claim 26

An apparatus according to claim 5 or 22, wherein said pressing means has first and second urging members having the same configuration, at opposite longitudinal ends of said shaft of said rotatable member.

Claim 27

An apparatus according to claim 20, wherein said drive transmission means transmits the driving force substantially without transmitting a force in a direction of the movement toward and away from said image bearing member.

Claim 28

An apparatus according to claim 18, wherein said transmission means includes a gear for transmitting the driving force from said driving means to an upstream side of said drive transmission member with respect to a drive transmission direction.

Claim 29

An apparatus according to claim 18, further comprising a supporting member for fixedly supporting a shaft of said image bearing member.

Claim 30

An apparatus according to claim 18, wherein said drive transmission member includes a projection and a groove for slidable engagement with the projection for transmitting the driving force from said driving means.

Claim 31

An apparatus according to claim 18, wherein said rotatable member is an image transfer rotatable member for transferring an image formed on said image bearing member to a transfer material.

Claim 32

An apparatus according to claim 18, wherein aid rotatable member is a charging rotatable member for electrically charging said image bearing member.

Claim 33

An apparatus according to claim 18, wherein said rotatable member is a cleaning roller for removing residual matter from said image bearing member.

Claim 34

An apparatus according to claim 18, wherein said rotatable member includes a belt for press-contact to said image bearing member and a roller for urging the belt to said image bearing member.

Claim 35

An apparatus according to claim 18, wherein said drive transmission member includes an absorbing portion for absorbing deformation toward and away from said image bearing member, transmitted from an upstream side of said drive transmission member in a direction of a drive transmission.

Claim 36

An apparatus according to claim 18 or 19, further comprising a supporting member for securely supporting said shaft of said drive transmission member.

Claim 37

An apparatus according to claim 34, wherein said shaft of said drive transmission member receives force in a direction crossing with an axial direction of said shaft of said drive transmission member, at a side thereof upstream with respect to said drive transmitting direction thereof.

Claim 38

An apparatus according to claim 18, wherein said shaft of the drive transmission member and said shaft of said press-contacted rotatable member are overlaid.

Claim 39

An image forming apparatus, comprising: an image bearing member rotatable about an axis; a rotatable member press-contacted to said image bearing member in relation to an image forming process for forming an image on said image bearing member, said rotatable member having a longitudinal shaft; driving means for driving said image bearing member; and transmission means for transmitting a driving force from said driving means to said image bearing member, said transmission means including coupling means for transmitting a rotational force substantially without imparting to said shaft a force in a radial direction thereof.

Claim 40

An image forming apparatus, comprising: an image bearing member rotatable about an axis; a rotatable member press-contacted to said image bearing member in relation to an image forming process for forming an image on said image bearing member, said rotatable member having a longitudinal shaft; driving means for driving said image bearing member; and transmission means for transmitting a driving force from said driving means to said image bearing member, said transmission means including coupling means for transmitting a rotational force substantially without imparting to said shaft a force in a radial direction thereof.

Claim 41

An apparatus according to claim 37, wherein said transmission means has a drive transmission member rotatably supported on a shaft for transmitting the driving force to said shaft substantially without changing an angular speed of the drive transmission means despite movement of said shaft relative to said transmission means.

Claim 42

An apparatus according to claim 38, wherein said press-contacted rotatable member comprises a longitudinal shaft and wherein said shaft of the drive transmission member and said shaft of said press-contacted rotatable member are overlaid.

Claim 43

An apparatus according to claim 38, further comprising a supporting member for securely supporting a shaft of said drive transmission member.

Claim 44

An apparatus according to claim 40, wherein the shaft of said drive transmission member receives force in a direction crossing with an axial direction of said shaft of said drive transmission member, at a side thereof upstream with respect to said drive transmitting direction thereof.

Claim 45

An apparatus according to claim 29, wherein said rotatable member is an image transfer rotatable member for transferring an image formed on said image bearing member to a transfer material.

Claim 46

An apparatus according to claim 37 or 39, wherein said image bearing member is supported for movement toward and away from said rotatable member.

Claim 47

An apparatus according to claim 29, wherein said rotatable member comprises elastic material.