Disc drive apparatus for more than one type of disc

摘要

The present invention provides a disc drive apparatus which identifies a type of a disc mounted on the apparatus by using reflected beam data obtained from a laser beam focused on the disc surface and other reflected beam data obtained from the laser beam being focused on the disc signal plane. For example, while forcibly changing the laser beam focusing point within a variable range at a predetermined velocity, a luminous energy signal or a focus error signal is used to count a time difference between a timing of focusing on the disc surface and a timing of focusing on the disc signal plane. According to the time difference obtained, the disc mounted is identified as a first type of disc or a second type of disc.