Patent ID: 8095040
Filing Date: 2012-01-10
Classification: G03G

Abstract:
1. An intermediate transfer-type image forming apparatus comprising: a transfer belt unit that is attachable to and detachable from the image forming apparatus and that has a transfer belt that primarily transfers a toner image formed on a photosensitive drum; a secondary transfer unit having a transfer mechanism portion that secondarily transfers the primarily transferred toner image to a paper; a side unit that is equipped with the secondary transfer unit; an optical sensor that detects a reference toner image on the transfer belt, the optical sensor being located downstream of the secondary transfer unit; and a shutter that protects a detection face of the optical sensor, wherein a separation/contact mechanism portion that is disposed so as to be brought into contact with both of the shutter and the secondary transfer unit is provided, and the separation/contact mechanism portion allows the shutter to move so as to open and allows the secondary transfer unit to move so as to separate from the transfer belt when the reference toner image is detected by the optical sensor, and allows the shutter to move to a location away from the transfer belt when the side unit equipped with the secondary transfer unit is drawn out from an apparatus main body to attach or detach the transfer belt unit.