Patent ID: 8794626

Claim:
A sheet thickness detecting device for detecting a thickness of a sheet passing through a conveying path, comprising: a fixed roller rotatably supported by a shaft so that the fixed roller faces one side of the sheet passing through the conveying path; a movable roller rotatably provided so that the movable roller and the fixed roller sandwich and feed the sheet, and configured to be displaced in accordance with the thickness of the sandwiched sheet; a swing member configured to rotatably support the movable roller and including a shaft so that the swing member is swung around the shaft, wherein the swing member further includes a detection target part formed in a manner that a distance between the detection target part and the shaft is greater than a distance between a position where the movable roller is supported by the swing member and the shaft; a detecting unit configured to detect the displacement amount of the detection target part of the swing member; a shaft roller including the shaft disposed on the upstream side of a position where the movable roller and the fixed roller are facing each other in a sheet feeding direction, and being rotatably supported by the swing member via the shaft; and a belt member configured to be stretched between the movable roller and the fixed roller and move along the sheet feeding direction.