Optical pickup system
AssigneePioneer Corporation
InventorsYoshitsugu Araki, Noriaki Murao
Life of this patent
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Abstract
An optical pickup system includes a light source, an objective lens, a beam splitter for splitting light received from the light source and reflected light from an optical disc, a detector for receiving the reflected light, a liquid crystal panel for providing passing light with a phase difference in accordance with a control signal and a control means for providing the control signal to the liquid crystal panel to eliminate an influence of birefringence of the optical disc.
Claims15
An optical pickup system, comprising:
- a light source;
- an objective lens;
- a beam separator for separating light received from the light source and reflected light from an optical disc;
- a detector for receiving the reflected light;
- a liquid crystal panel for providing passing light with a phase difference in accordance with a control signal;
- and
- a controller for providing the control signal to the liquid crystal panel to eliminate an influence of birefringence of the optical disc by causing the liquid crystal panel to provide the passing light with the phase difference in accordance with the control signal,
- wherein the controller adjusts a voltage applied to the liquid crystal panel such that an output signal generated by the detector has a maximum value.
An optical pickup system for reproducing information from a plurality of optical discs including a first optical disc of a first thickness and a second optical disc of a second thickness, comprising:
- a light source;
- an objective lens;
- a beam separator for separating light received from the light source and reflected light from an optical disc;
- a detector for receiving the reflected light;
- a liquid crystal panel for providing passing light with a phase difference in accordance with a control signal;
- and
- a controller for providing the control signal to the liquid crystal panel, wherein the controller controls the liquid crystal panel such that an influence of birefringence of the first optical disc is eliminated by causing the liquid crystal panel to provide the passing light with the phase difference in accordance with the control signal while the optical pickup system reproduces information from the first optical disc, and an influence of birefringence of the second optical disc is eliminated and a numerical aperture is limited while the optical pickup system reproduces information from the second optical disc.
Dependencies are inferred from the claim text.