Patent ID: 7558176

Claim:
A method for preventing an optical disk from being scraped, comprising: moving a pickup head of an optical read/write device to a focal position in which laser light emitted from said optical read/write device is focused on a read/write surface of an optical disk; and setting a vertical movement boundary in a vertical direction for said optical read/write device according to said focal position; wherein said vertical movement boundary has an upper boundary and a bottom boundary, said vertical direction is perpendicular to said read/write surface of said optical disk, and the process of said setting said vertical movement boundary comprises: taking said focal position as a detection basis; shifting a first distance L 1 from said focal position upward to an upper bound point in said vertical direction; and shifting a second distance L 2 from said focal position downward to a bottom bound point in said vertical direction; and wherein a first horizontal plane parallel with said optical disk comprising said upper bound point is said upper boundary and a second horizontal plane parallel with said optical disk comprising said bottom bound point is said bottom boundary.