Coarse position error signal generation in an optical disk storage system employing course servo tracks

Abstract From the Canadian patent

A linear detector (61) for use in a coarse positioning servo system of an optical system. The linear detector produces an error signal having an amplitude linearly proportional to the distance that a relatively narrow strip of light energy (63) falls on a collection surface (62) of the detector as measured relative to a fixed reference point on said collection surface. Two reference signals (65, 66) are derived from circuitry associated with the collection surface. A first reference signal (65) has an amplitude proportional to the intensity of the focused light energy and the location that said light energy falls on the collection surface relative to a first reference point. A second …