Sanyo Electric Co. Patent applications |
Patent application number | Title | Published |
20090290475 | OPTICAL PICKUP APPARATUS - An optical pickup apparatus comprising: a diffraction grating configured to diffract laser light from a laser diode so that signals recorded in first and second optical discs are selectively reproduced, thicknesses of protective layers between surfaces and signal recording surfaces of the first and second optical discs being different from each other; a polarization beam splitter configured to divide laser light from the diffraction grating into first and second laser lights whose light amounts are substantially the same; a first objective lens configured to focus the first laser light onto the signal recording surface of the first optical disc; a second objective lens configured to focus the second laser light onto the signal recording surface of the second optical disc; and a photodetector configured to be applied with return lights of the first and second laser lights reflected from the signal recording surfaces of the first and second optical discs. | 11-26-2009 |
20090129245 | Optical Pickup Apparatus - An optical pickup apparatus comprising: an objective lens focusing laser light emitted from a laser diode to a signal recording layer of an optical disc; a photodetector including a substantially square light-receiving region made of first to fourth sensors divided by boundaries in a first direction corresponding to a tracking direction and a second direction crossing the first direction, the light-receiving region being irradiated with reflected light of the laser light which is reflected from the signal recording layer thereof; and a half mirror reflecting the laser light in a direction of the objective lens and allowing the reflected light to pass therethrough in a direction of the photodetector, the boundary in the second direction for dividing the first to fourth sensors in the light-receiving region being set according to a shape of a spot of the reflected light directly applied from the half mirror to the light-receiving region. | 05-21-2009 |
20090073857 | OPTICAL PICKUP APPARATUS - An optical pickup apparatus comprising: a collimating lens configured to convert laser light emitted from a laser diode, from diffused light into parallel light; an objective lens; and a prism configured to guide the laser light emitted from the collimating lens to the objective lens, the prism including: a first face that the laser light emitted from the collimating lens enters; a second face that reflects the laser light entering the first face; and a third face that reflects the laser light reflected from the second face in a direction of the second face, and emits the laser light reflected again from the second face in a direction of the objective lens. | 03-19-2009 |