| 摘要 |
PROBLEM TO BE SOLVED: To inexpensively provide the optical head capable of high precision assemblage and stable operation. SOLUTION: A laser diode chip 1 is fixed to a heat sink 3, and this heat sink 3 is fixed by a photodiode chip 2. Laser light is emitted forwardly and backwardly by the laser diode chip 1 respectively. The heat sink 3 is formed with a mirror 3a for reflecting the laser light. The forward emitting light 1a of a laser diode is reflected by the mirror 3a to pass through a hologram optical element 9 and a lens 10, and is converged on an optical disk. Reflected light from the optical disk is reversely advanced in the same optical path, diffracted by the hologram optical element 9, and is then detected by light receiving parts 2a-2h of the photodiode chip 2. The backward emitting light 1b of the laser diode is detected by a light receiving part 2i of the photodiode chip 2 for the purpose of controlling an injection current into the laser diode chip 1 so as to make its light emitting quality constant. |
