Image forming apparatus that suppresses deterioration in image quality

摘要

An image forming apparatus includes: an image carrier; a transfer member arranged so as to face the image carrier; and a non-transferred toner adhesion unit that causes a non-transferred toner to adhere to an inter-sheet area present on the image carrier during a period of continuous image formation in which images are continuously formed on the image carrier. The transfer member is a foam roller. The image forming apparatus further includes a contacting and separating unit that causes the foam roller and the image carrier to come into contact with and be separated from each other. The contacting and separating unit separates the image carrier and the transfer member when the inter-sheet area present on the image carrier passes through a transfer area in which the image carrier and the transfer member face each other in association with rotation of the image carrier.

主权项

1. An image forming apparatus comprising:
an image carrier that is rotatably provided and carries a toner image on a surface thereof; a transfer member arranged so as to face the image carrier; and a non-transferred toner adhesion unit that causes a non-transferred toner not to be transferred onto a sheet to adhere to an inter-sheet area present on the image carrier during a period of continuous image formation in which images are continuously formed on the image carrier, wherein: the transfer member includes a foam roller, the image forming apparatus further comprises a contacting and separating unit that causes the transfer member and the image carrier to come into contact with and be separated from each other, the contacting and separating unit separates the image carrier and the transfer member when the inter-sheet area present on the image carrier passes through a transfer area in which the image carrier and the transfer member face each other in association with a rotation of the image carrier, the toner image is formed to a trailing end of the sheet such that there is no margin at an edge at the trailing end of the sheet in a sheet conveying direction, the image forming apparatus has a first image forming mode in which the toner image is formed on the sheet such that there is a margin at edges of an entire perimeter of the sheet and a second image forming mode in which the toner image is formed to the trailing end of the sheet such that there is no margin at the edge at the trailing end of the sheet, a width of the inter-sheet area in a direction of rotation of the image carrier is larger in image formation in the second image forming mode than in image formation in the first image forming mode by a length of a circumference of the transfer member or more, and in the image formation in the second image forming mode, a time during which the transfer member is in contact with the image carrier, and a bias with a polarity opposite to that in the first image forming mode is applied in the inter-sheet area is set to at least a time required for the transfer member to rotate once or more, and a time during which the transfer member is in contact with the image carrier, and a bias with a same polarity as that in the first image forming mode is applied is set to at least a time required for the transfer member to rotate once or more.