Patent ID: 8086155

Claim:
A transfer device to transfer an image onto a recording medium directly or indirectly, the transfer device comprising: an endless belt member extended between a drive roller rotated by a drive source thereof and a driven roller rotated with the drive roller, the endless belt member configured to receive the image formed on a surface of an image carrier part of an image forming apparatus onto either a surface thereof or the recording medium carried on the surface thereof while moving according to rotations of the drive roller; an image detector configured to detect the image formed on the endless belt member directly or the recording medium carried on the endless belt member, the image detector disposed facing the driven roller in a circumferential direction of the endless belt member; and a rotation speed detector configured to detect a rotation speed of the driven roller, wherein the image detector is positioned based on a position of the driven roller with a positioning member, at an upstream side from the drive roller in a belt travel direction, and facing an outer surface of the endless belt member where an inner surface thereof is held in contact with the driven roller, and wherein the image detector comprises multiple sensors disposed along a longitudinal axis of the driven roller.