Patent ID: 6154434
Filing Date: 2000-11-28
Classification: G11B

Abstract:
An optical pickup for writing and/or reading an optical signal recorded on an optical recording medium, comprising:a light source;a collimator lens for condensing the light emitted from said light source into parallel light rays;an objective lens for condensing said parallel light rays on an optical recording medium;a polarization beam splitter interposed between said collimator lens and said objective lens for reflecting part of a return light reflected from said optical recording medium as an optical signal light and transmitting the remaining part of said return light through said optical recording medium as a servo signal light;a first photo-detector for detecting the light reflected from said polarization beam splitter as an optical signal light;means for condensing the light reflected from said polarization beam splitter on said first photo-detector;a second photo-detector for detecting the light transmitted through said polarization beam splitter as a servo signal light;means for condensing the light transmitted through said polarization beam splitter on said second photo-detector; andsaid first photo-detector for detecting an optical signal and said second photo-detector for detecting a servo signal being fabricated on a single substrate, whereinsaid polarization beam splitter is integrally coupled with a condensation device having the function of condensing the light containing the optical signal reflected from said polarization beam splitter, a reflector for reflecting said light toward said first photo-detector, and a polarizer/splitter for splitting said light into two polarized light components thereby to constitute a composite polarization beam splitter (PBS);said polarization beam splitter, said condensation, said reflector, and said polarizer/splitter are arranged in such positions that said light containing the optical signal is passed first through said polarization beam splitter, then said condensation device, then said reflector and then said polarizer/splitter in that order.