| 摘要 |
PURPOSE:To provide a small-sized and inexpensive optical head with simple constitution reducing the number of parts. CONSTITUTION:In the optical head 1, a prism 5 is arranged between a semiconductor laser 2, a photodetector 3 and an optical disk 4, and an objective lens 6 is arranged between the optical disk 4 and the prism 5. Further, a collimate lens 7 is arranged between the semiconductor laser 2, the photodetector 3 and the prism 5. Then, the prism 5 on whose incident end surface 5a a special coat splitting a beam is applied. The incident end surface 5a applied with such as special coat whose surface is set so that a beam shape of a light beam outgoing from the semiconductor laser 2 is shaped from an ellipse to a circle, and the incident beam is refracted in the dirrection orthogonal to the optical disk 4 surface. Further, a total reflection coat is performed on the surface 5c as a reflection end surface. |
