Image forming apparatus to change image magnification by controlling sheet conveyance speed

摘要

Provided is an image forming apparatus which enables control to change a longitudinal magnification of an image transferred on a sheet in a sheet conveyance direction by changing a rotation speed of a second transfer section while prohibiting misalignment of transfer without requiring a changing time of the longitudinal magnification which causes the decreasing of productivity.

主权项

1. An image forming apparatus, comprising:
an image carrier to carry a toner image; a toner image forming section to form the toner image on the image carrier: an intermediate transfer member to transfer the toner image: a first transfer section to transfer the toner image on the image carrier onto the intermediate transfer member, and a second transfer member to conduct secondary transfer in which the toner image transferred by the first transfer section is transferred onto a sheet and convey the sheet, a control section; a registering section located at an upstream side of the second transfer section to adjust sheet conveyance timing when transferring onto the sheet and to transfer the sheet, and a fixing section located at a downstream side to fix the toner image on the sheet on which the toner image is transferred, wherein the control section controls a magnification of the toner image transferred onto the sheet at a secondary transfer position in a sheet conveyance direction to be a target value by changing a rotation speed of the second transfer section while a rotation speed of the intermediate transfer member remains unchanged so as to change a conveyance speed of the sheet while controlling at least a sheet conveyance speed of the register section or a sheet conveyance speed of the fixing section in accordance with the target value of the magnification of the toner image in the sheet conveyance direction.