Patent ID: 8441339

Claim:
A displacement detector used for a detection of a relative displacement of a fixed member and a movable member relatively movable with respect to the fixed member, comprising: a first member secured to the fixed member and composed of an electrical insulator; and a second member undergoing relative movement with respect to the fixed member, integrally with the movable member, the second member being disposed opposite to the first member and perpendicular to a direction of the relative movement, and the second member being composed of an electrical insulator, wherein either one of the first member and the second member includes an IC tag for detection performing non-contact communication with a peripheral device, and the other includes a blocking member composed of an electrical conductor that blocks the communication performed by the IC tag for detection, and when the second member undergoes at least a predetermined amount of relative movement with respect to the first member, starting from an initial state in which the first member and the second member are relatively overlapped, the IC tag for detection moves from inside to outside a region of the blocking member, or from outside to inside the region thereof, as viewed from a direction perpendicular to the direction of the relative movement.