Patent ID: 7903522
Filing Date: 2011-03-08
Classification: G11B

Abstract:
1. A disk playback apparatus, comprising: first reading means for obtaining a first signal that is recorded onto a disk-shaped recording medium with a length and pitch of pits by modulating first digital information according to a required format; second reading means for reading second digital information that is recorded so as to be superimposed on the first signal by wobbling the pits, wherein the pits are wobbled in one of a positive direction and a negative direction during a first period and wobbled in the other direction during a second period for each of a plurality of bits constituting the second digital information; a plurality of signal integrating means for integrating the second digital information read by the second reading means according to a relative position from a sync signal contained in the first signal read by the first reading means, wherein each of the plurality of signal integrating means integrates each of the bits constituting the second digital information a plurality of times; and determining means for determining an output of the plurality of signal integrating means to decode the plurality of bits of the second digital information in a unit period of each sync signal serving as the second digital information.