| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical pickup at a low cost with a small size by arranging a laser light source, an output control photo detection means and a return light detection means on a same board so as to suppress increase in number of components of an optical system and increase in the size of the optical system. SOLUTION: A laser/photo detector unit 5 is formed by arranging a beam laser diode 1 emitting a laser beam, an output control detector detecting part of the laser beam, and return light detectors 4a, 4b detecting a returned laser beam on the same board. The laser beam emitted from the laser diode 1 is led to a polarized light hologram via a mirror 2 and partial reflected light is detected by C1 , C2 on the photo detector 3. On the other hand, the laser beam transmitted through the polarized light hologram is reflected in an optical disk and diffracted by the hologram grooves and detected by a light receiving sections a1-a5, b1-b5 of the return light detectors 4a, 4b. |
