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AssigneeMatsushita Electronics Corporation
InventorsHideyuki Nakanishi, Akira Ueno, Hideo Nagai, Akio Yoshikawa
Estimating the term…
An optical head for optical recording and reproducing apparatuses is disclosed. The optical head comprises a semiconductor laser, a mirror for reflecting a light beam emitted from the semiconductor laser, a diffraction grating for dividing the light beam into zero order, plus and minus first-order beams. It also comprises a holographic diffraction grating being arranged at an optical path of the beams divided by the diffraction grating, an objective lens for focusing the beams on a disk and causing the beams reflected from the disk to be incident on the holographic diffraction grating to diffract the beams, and a photodetector for detecting a tracking error signal by receiving the beams diffracted by the holographic diffraction grating. The semiconductor laser has a beam incident area onto which the beam reflected from the disk is incident. The beam incident area acts to scatter or absorb the incident beam. As a result, the optical head is able to obtain a stable tracking error signal.
An optical head comprising:
An optical head comprising:
Dependencies are inferred from the claim text.