Patent ID: 7012858

Claim:
A method for checking the existence of an optical disk in a disk drive using a focus error signal, comprising the steps of: (a) receiving a focus error signal; (b) sampling the received focus error signal at constant intervals; (c) summing the values of the sampled focus error signal, which are less than a first predetermined reference level; (d) determining whether the summed value is greater than a predetermined judging level; (e) judging the existence of the optical disk in the disk drive based on the result in the determining step (d); wherein the step (b) is started when the value of the focus error signal exceeds the first predetermined reference level, while moving an optical pickup; and wherein the predetermined reference level includes first and second predetermined reference levels, where the first predetermined reference level is for starting said sampling step (b) and the second predetermined reference level is for sampling the focus error signal.