Rader Fishman & Grauer PLLC
Optical pickup device, optical disk drive, optical device and composite optical element
An optical pickup device is provided which includes a double-wavelength objective lens (34) that collects a light beam selectively emitted from a light-emitting/-detecting element (31) that selectively emits a plurality of light beams different in wavelength from each other, and also return light from an optical disk (2), a first diffraction grating (45) that splits the light beam emitted from a light-emitting/-detecting element (31) into three beams including a zero-order light beam and positive and negative first-order light beams, a second diffraction grating (46) that diffracts the return light for traveling along a light path separate from that of the outgoing light, and a third diffraction grating (47) that corrects a light-path deviation by diffracting the positive first-order light beam diffracted by the second diffraction grating (46). The light-emitting/-detecting element (31) provides a focusing error signal FE by detecting the negative first-order light beam diffracted by the third diffraction element (47), and a tracking error signal by detecting return portions of the positive and negative first-order light beams from the first diffraction grating (45).
Sony Corporation
G G G G
G11B G11B G11B G11B
inventional additional additional inventional
Takeshi Kiyoshi Norio Tetsu Satoru Masahiro Junichi
Kubo Toyota Fukasawa Tanaka Ishii Saito Suzuki