Patent ID: 6483787
Filing Date: 2002-11-19
Classification: G11B

Abstract:
A reproduction apparatus for selectively playing back a first optical disc wherein two side faces of each of grooves or lands formed thereon are wobbled at a first frequency and information is recorded on the wobbled grooves or lands and a second optical disc wherein one of two side faces of each of grooves or lands formed thereon is wobbled at a second frequency while the other side face of each of the grooves or lands is formed as a flat face and information is recorded on the grooves or lands, comprising:an optical head for irradiating light upon a predetermined one of the grooves or lands and those of the lands or grooves adjacent the predetermined groove or land; first detection means for detecting reflected light from the predetermined groove or land; second detection means for detecting reflected light from the lands or grooves adjacent the predetermined groove or land; first calculation means for calculating a difference between the reflected light of said first detection means and the reflected light of said second detection means to produce a first tracking error signal; second calculation means for calculating a difference between the reflected light from one and the reflected light from the other of the lands or grooves adjacent the predetermined groove or land detected by said second detection means to produce a second tracking error signal; discrimination means for discriminating whether an optical disc loaded on said reproduction apparatus is the first optical disc or the second optical disc; and tracking controlling means for performing, when said discrimination means discriminates that the loaded optical disc is the first optical disc, tracking control based on the first tracking error signal produced by said first calculation means, but performing, when said discrimination means discriminates that the loaded optical disc is the second optical disc, tracking control based on the second tracking error signal produced by said second calculation means.