ERROR SIGNAL DETECTOR FOR OPTICAL RECORDER

摘要

PURPOSE: An error signal detector for an optical recorder is provided to be capable of detecting an oblique error signal having high accuracy and precision by respectively performing the photoelectric conversion for overlapped portions between an 0 order diffraction light and a +/- one order diffraction light and only the 0 order diffraction light. CONSTITUTION: The error signal detector comprises an optical detector(30) and a circuit part(50). In the optical detector(30), row directional division boundary lines and column directional division boundary lines are respectively parallel to a radial tangent line and a track tangent line of a record medium, and four light receive areas(A1,A2)(B1,B2)(C1,C2)(D1,D2) are divided into two division plates(A2,B2,C2,D2)(A1,B1,C1,D1) by a division boundary line parallel to the track tangent line to photoelectrically convert input light. The circuit part(50) compares phases between detection signals of the division plates and then an oblique error signal from the phase comparison signal.