Oblon, Spivak, McClelland, Maier & Neustadt, L.L.P.
Optical pickup apparatus and optical disc apparatus
An optical pickup apparatus and an optical disc apparatus are adapted to raise the efficiency of utilization of the lasers of the apparatus for accurately detecting tracking errors by raising the intensity ratio of the beam of the 0-th order to the beams of the ±1st orders produced by splitting of the laser beam of the wavelength to be subjected to division by three. The optical pickup apparatus includes a light emitting section for emitting a first laser beam having wavelength λ1 and a second laser beam having wavelength λ2 different from the wavelength λ1. 
Sony Corporation
G G G
G11B G11B G11B
inventional inventional additional
Kiyoshi Norio Junichi Masahiro
Toyota Fukasawa Suzuki Saito