Patent ID: 6703601
Filing Date: 2004-03-09
Classification: G01D

Abstract:
An optical encoder for detecting position and/or speed of a movable object, comprising:a light source to emit a beam; a conversion device to be operatively connected to the movable object and having a plurality of lens elements arranged periodically with a predetermined pitch, to convert the beam emitted from said light source into a plurality of shifting beams periodically distributed and shifting in accordance with a motion of said movable object, said plurality of lens elements being provided on a light incident surface side and a light outgoing surface side in a pair; and a light receiving section having plurality of a light sensing zones and a plurality of light non-sensing zones which are arranged to be distributed alternately and periodically along a shifting direction of said shifting beams, and disposed stationarily with respect to said shifting beams, wherein said plurality of shifting beams are converged into a plurality of parallel beams, by the plurality of lens elements, such that each of said plurality of shifting beams is converged to a width of one of said light sensing zones, at the time of going out of said conversion device.