Patent ID: 11971670
Assignee: CANON KABUSHIKI KAISHA
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An image forming apparatus comprising:
a photosensitive drum configured to bear a toner image;
an intermediate transfer belt that is endless and is configured to form a primary transfer portion by being in contact with the photosensitive drum, wherein, when transferred, the toner image is primarily transferred onto the intermediate transfer belt from the photosensitive drum at the primary transfer portion;
a plurality of stretching rollers that includes an inner roller and is configured to stretch the intermediate transfer belt;
an outer roller configured to form a secondary transfer portion by being in contact with the intermediate transfer belt at a position facing the inner roller, and configured to secondarily transfer the toner image from the intermediate transfer belt onto a recording material at the secondary transfer portion;
a power source configured to apply a voltage to the outer roller;
a registration roller arranged upstream of the secondary transfer portion in a conveyance direction of the recording material, wherein the registration roller is configured to regulate orientation of the recording material by being in contact with the outer roller and the registration roller; and
a control unit configured to control a secondary transfer voltage to be output by the power source for a secondary transfer,
wherein the intermediate transfer belt has conductivity enabling a current flow in a circumferential direction, and
wherein, in the conveyance direction of the recording material, the control unit controls to acquire information regarding a timing at which the recording material passes through a contact portion with the registration roller, and controls, based on the acquired information, a target value of the secondary transfer voltage for the secondary transfer to the recording material to be a first target value at a timing at which a leading edge of the recording material comes into contact with the secondary transfer portion, and a second target value of the secondary transfer voltage applied at a timing before a trailing end of the recording material comes into contact with the secondary transfer portion and after a timing at which the trailing end of the recording material passes through the contact portion with the registration roller, which has an absolute value larger than the first target value.