Patent ID: 8688006

Claim:
A drive transmission device, comprising: drive transmission members to transmit drive from a drive source to a driven object, at least a part of the drive transmission members formed by a gear train including a detection target gear; a detection device to detect the rotational position of the detection target gear, the detection device including a position detection member provided to the detection target gear, and configured to change in position in accordance with the change in rotational position of the detection target gear, and a detection unit disposed in the vicinity of the detection target gear, and configured to detect the position detection member at a detection position, the detection unit including a first detection member and a second detection member disposed facing each other, each of the first detection member and second detection member including a facing surface, an opposite surface, and side surfaces; and a shape-variable protection member made of a conductive material and including a first portion disposed in contact with the opposite surface and the side surfaces of the first detection member and a second portion disposed in contact with the opposite surface and the side surfaces of the second detection member, the shape-variable protection member being disposed free from the respective facing surfaces of the first detection member and the second detection.