Patent ID: 7403295
Filing Date: 2008-07-22
Classification: G02B,H04N

Abstract:
1. A position-detecting system, comprising: a movable member that is moved in a two-dimensional plane relative to a fixed member; a light source unit that is provided on one of said fixed member and said movable member, and said light source unit comprises a plurality of light emitting devices which is separately disposed at a predetermined distance; a position-sensing device that is provided on another one of said fixed member and said movable member, and which receives light from said light source unit and detects a position where said light is received; a light-source controller that selectively turns on one of said plurality of light emitting devices in a predetermined order; and a calculator that calculates a direction, displacement, and rotation of motion of said movable member in accordance with two pairs of position data, in which one pair of position data represents positions where light from a pair of light emitting devices is detected and the other pair of position data represents positions where light from said pair of light emitting devices is detected at a predetermined time interval after said one pair of position data is detected.