ERASING METHOD FOR OPTICAL INFORMATION

PURPOSE:To enable sufficient erasure by irradiating a recording medium with a laser beam spot while wobbling it at a frequency higher then the pre-groove follow-up performance of the laser beam by a quantity which does not exceeds the width of a projection or recessed part of the recording medium. CONSTITUTION:The information recorded at the projection or recessed parts 1 of the recording medium is irradiated with the laser beam spot 2 which is converged into one at the frequency higher than the pre-groove follow-up performance of the laser beam by the quantity which does not exceed the width of the recessed or projection parts 1 from the center of the projection or recessed part 1 to both adjacent projection or recessed parts, so that the information is erased. Consequently, the erasure of the information for obtaining a reproducing signal of good quality with smaller power than recording laser power becomes possible.