Optical pickup device

摘要

The device has a beam divider (12) near a laser diode (11), allowing through a beam of a certain wavelength and reflecting another beam of a certain wavelength. A collimator lens (13) converts the reflected beam into a parallel beam and is mounted at right angles to the laser diode. A prism (14) reflects the parallel beam from the collimator lens in a certain direction. A liquid crystal shutter (15) converts the S wave into a P wave, and the P wave into an S wave. A diffraction hologram (16) selectively diffracts the beam. An objective lens (17) focusses the beam on the disc (D).