Patent ID: 6320831
Filing Date: 2001-11-20
Classification: G11B

Abstract:
A method of processing signals for an optical disc device, in which a track format optical disc (5) has two land areas (3, 4) of a double spiral structure on which information is recorded, said land areas being arranged adjacent to each other sandwiching between a wobbling groove (1) on which wobble information is recorded by wobbling, an has non-wobbling grooves (2) arranged outside said land areas, the method comprising the steps of:detecting a first reflected light obtained by irradiating the land areas;using a first split photo detector (21) disposed at a first prescribed position to detect a second reflected light obtained by irradiating the wobbling groove (1) or the non-wobbling groove (2) located adjacent to one side of the land area providing the reflected light;using a second split photo detector (23) disposed at a second prescribed position to detect a third reflected light obtained by irradiating the wobbling (1) groove or the non-wobbling groove (2) located adjacent to the other side of the land area providing the reflected light; andrecording or reproducing information on or from the land area while executing tracking control based on the first, second, or third reflected light or on a combination of these lights, whereinphases of a sum signal and a difference signal are compared between a first push-pull signal obtained from an output from the first split photo detector (21) and a second push-pull signal obtained from an output from the second split photo detector (23), in order to determine from the phase relationship obtained between the sum and difference signals which land area (3, 4) is providing said first reflected light.