Patent ID: 8213282

Claim:
A method for identifying a disk type of an optical disk, wherein the optical disk is inserted into an optical disk drive, the method comprising: moving a pickup head of the optical disk drive towards the optical disk; observing a reflected signal as said pickup head of the optical drive is moving on the optical disk; determining a first period between motion initiation of the pickup head and a first peak occurrence of the power of the reflected signal, wherein the first peak occurrence corresponds to an polycarbonate layer of the optical disk; determining a second period between the first peak occurrence and a second peak occurrence of the power of the reflected signal, wherein the second peak occurrence corresponds to an reflection layer of the optical disk; determining an identification threshold value according to a predetermined function which is varied in accordance with a length of the first period; comparing the second period with the identification threshold value to obtain a comparison result; and identifying the disk type of the optical disk according to the comparison result.