Patent ID: 7986416

Claim:
A size and position detecting system configured for detecting a size and a position of a cutting tool, the size and position detecting system comprising: a laser sensor comprising: an emitter positioned to emit a laser beam; and a receiver positioned opposite to the emitter, the receiver to receive the laser beam from the emitter; and a controller to compute a first time of how long the emitter emits the laser beam, and to compute a second time of how long the receiver receives the laser beam when the cutting tool moves along a first direction perpendicular to and coplanar with a substantially straight line connecting the emitter and the receiver, wherein the controller records a first position of the cutting tool at a moment when the second time is less than the first time, and a second position of the cutting tool when the second time remains changeless for a predetermined amount of time, to determine whether the cutting tool is off-centered according a difference between the first and second positions along the first direction.