Unbalance disc detection apparatus and unbalance disc detection method

摘要

An unbalance disc detection apparatus with a photodetector for receiving at its photo reception region reflection light from a disc on which a laser light is irradiated, and a push-pull signal calculation section for obtaining a change of a light quantity detected by the photo reception region as a push-pull signal, whereby an unbalance disc discriminating section discriminates whether or not a level of the push-pull signal exceeds a threshold value set in correspondence to a predetermined measurement rotation speed.