Optical information recording and reproducing apparatus and method for different spot size type media

摘要

Optical information recording and reproducing apparatus and method of the invention perform the recording and reproducing for various types of information recording media each having a converged laser spot size different from the spot sizes of the other types. The optical information recording and reproducing apparatus includes a spot size recognizing circuit for recognizing a spot size suitable for an information recording medium to be loaded, and performs erasing, recording, and reproducing to the information recording medium by defocusing or by off-tracking based on the spot size recognized by the spot size recognizing circuit.