| 摘要 |
PROBLEM TO BE SOLVED: To realize a light pickup device with which miniaturization is possible, productivity is good and the easy improvement in the heat radiation characteristic of a semiconductor is possible. SOLUTION: The laser photodiode unit 32 of the light pickup device has a semiconductor substrate 41A which is formed with plural photodiode elements, a sub-mount 42A which is joined onto this semiconductor substrate 41A and has a heat radiation function, a semiconductor laser 43A which is joined atop this sub-mount 42A and an optical prism 44A which is joined onto the semiconductor substrate 41A and directs the progressing direction of the laser beam emitted from the semiconductor laser 43A to the direction, nearly perpendicular to the semiconductor substrate 41A. The laser beam emitted from the semiconductor laser 43A is irradiated onto an optical disk. The return light is diffracted by a hologram and is made incident on the photodiode elements on the semiconductor substrate 41A. |
