ERASURE METHOD FOR OPTICAL INFORMATION

PURPOSE:To obtain a reproduction signal with excellent quality by radiating a converged laser beam spot while being shifted not in excess of the width of a recessed part or a projection in both adjacent directions from the center of the recessed part or the projection. CONSTITUTION:The optical information is erased by radiating a converged laser beam spot 3 to a position from the center of a projection 1 or a recessed part 2 in the direction of both adjacent projection or recessed parts by a shift quantity not in excess of the width of the recessed part or the projection once. Thus, sufficient erasure is attained with an erasure laser power less than the recording laser power. Then the erasure of information suitable for obtaining a reproduction signal with excellent quality is attained with a power less than the recording laser power.