Patent ID: 8194523
Filing Date: 2012-06-05
Classification: G11B

Abstract:
1. An optical disc apparatus for reproducing information from an optical disc, comprising: a light source for emitting laser light; a light source drive unit for driving said light source; an optical element having a function of splitting said laser light into a plurality of light beams; wherein, when said function of splitting is made effective, said laser light is split into one main beam and a plurality of sub-beams, and when said function of splitting is made ineffective, said laser light is not split and only the main beam remains; an optical element control unit for controlling whether to make said function of splitting of said optical element effective or ineffective; a focusing means for focusing the main beam and the plurality of sub-beams onto said optical disc; and a detection unit for detecting said main beam reflected by said optical disc; wherein, adjustment of a power of the main beam emitted from said focusing means is performed by emission power control of said light source drive unit to said light source, based on an amplitude of a reproduced signal obtained by said detection unit when the optical disc is reproduced by irradiating the main beam onto the optical disc, under control of said optical element control unit and under a condition that said function of splitting is made ineffective, and an amplitude of a reproduced signal obtained by said detection unit when the optical disc is reproduced by irradiating the main beam and the plurality of sub-beams onto the optical disc, under control of said optical element control unit and under a condition that the function of spitting is made effective.