Patent ID: 7634943

Claim:
A sheet member information acquiring device configured to acquire information about a sheet member and output the information, the device comprising: a load-applying member configured to apply a load to the sheet member; a rotation bearing configured to hold the load-applying member rotatably around at least a rotation axis; wherein said load-applying member has a protrusion provided at an end portion of said load-applying member subjected to contact with the sheet member, the protrusion being located at a position offset by a predetermined distance from the rotation axis; a changing portion configured to change relative positions of the sheet member and said load-applying member while in a contact state; and a detecting portion configured to detect a displacement of said load-applying member, wherein the detecting portion comprises at least one of an acceleration sensor, a pressure sensitive element and a displacement measuring unit, and wherein the sheet member information acquiring device acquires the information about the sheet member on the basis of information provided by the detecting portion.