Patent ID: 7230896

Claim:
An optical disk reproducing device comprising: a motor for rotating an optical disk having at least one of a first area and a second area; an optical head for receiving a spot light after being reflected on the optical disk; a signal generating section for generating a comparison reference signal from an output signal of the optical head; a comparing section for comparing the comparison reference signal with a predetermined threshold value, and generating a comparison signal containing at least one of a first signal status corresponding to the first area and a second signal status corresponding to the second area; and a control section for observing signal status of the comparison signal at least throughout a duration during which the spot light goes round once on the optical disk, and making a decision based on the observed result, about in which of the first area and the second area the spot light falls, wherein the signal generating section generates a bottom hold signal of the output signal from the optical head as the comparison reference signal; and the comparing section generates the comparison signal which takes the first signal status when the comparison reference signal came short of the predetermined threshold value, and takes the second signal status when the comparison reference signal exceeded the predetermined threshold value.