Patent ID: 7995426
Filing Date: 2011-08-09
Classification: G11B

Abstract:
1. An optical disk apparatus for reading information which is recorded on an optical disk, wherein, the optical disk includes: a data area for recording main information; and an identification area for recording identification information for identifying the optical disk, the identification area having optical characteristics different from those of the data area, the optical disk apparatus comprising: an optical pickup for radiating light onto the optical disk and detecting reflected light from the optical disk to generate a light amount signal; a detecting section for outputting a detection signal whenever a change in the signal level of the light amount signal is detected; a retriggerable pulse signal output section for generating a pulse signal which continues for a first predetermined time (B), the retriggerable pulse signal output section being triggered by the detection signal; and an area determination section for determining whether an irradiated position of the light is within the identification area or not based on the pulse signal, wherein the area determination section is adapted for comparing a duration of the pulse signal with a second predetermined time (C) longer than the first predetermined time (B) and determines whether the irradiated position of the light is within the identification area or not based on the result of the comparing.