Patent ID: 11934116
Assignee: KYOCERA DOCUMENT SOLUTIONS INC.
Field: Optics (Instruments)
Classification: CPC G  B | IPC B  G

Claim 0:
1. A transfer unit that transfers a toner image formed on an image carrying member, to a recording medium as the recording medium passes through a transfer nip, the transfer unit comprising:
a transfer roller including a metal shaft and an elastic layer laid around an outer circumferential face of the metal shaft, the transfer roller forming the transfer nip by keeping the elastic layer in pressed contact with the image carrying member, the transfer roller including a first roller and a second roller, the second roller being arranged downstream of the first roller in a conveyance direction of the recording medium and being different from the first roller in a length of the elastic layer in an axial direction;
a roller switching mechanism that arranges the first or second roller selectively at a reference position where the first or second roller forms the transfer nip by being kept in pressed contact with the image carrying member;
an upstream-side guide arranged upstream of the transfer nip in the conveyance direction of the recording member; and
a downstream-side guide arranged downstream of the transfer nip in the conveyance direction of the recording member,
wherein
when the first roller moves to the reference position by the roller switching mechanism, the second roller moves to a first retracted position behind the downstream-side guide, and
when the second roller moves to the reference position by the roller switching mechanism the first roller moves to a second retracted position behind the upstream-side guide and opposite the image carrying member across the upstream-guide, wherein
the downstream-side guide has a first roller guide portion that makes contact with the metal shaft of the second roller,
the upstream-side guide has a second roller guide portion that makes contact with the metal shaft of the first roller,
when the first roller moves to the reference position, the metal shaft of the second roller moves along the first roller guide portion and the second roller is guided to the first retracted position, and
when the second roller moves to the reference position, the metal shaft of the first roller moves along the second roller guide portion and the first roller is guided to the second retracted position.