| 摘要 |
PURPOSE:To miniaturize an optical head, to simplify assembly and adjustment and to stably detect a light beam by providing a non-polarizing reflection surface on a transmission means and turning a light beam from a light source toward a focusing means through the reflection surface. CONSTITUTION:A non-polarizing light beam split surface (m) is used as a separation means for the light beam generated from a semiconductor laser element 2 and the plane of polarization of the light beam generated from the laser element 2 is rotated by about 45 deg., for example, against the reference axis included in a plane parallel with a direction where the light beam is transmitted on the polarizing light beam split surface for separating the light beam and making it incident on photodetectors 26 and 28, that is, a Y-axis. Therefore, the device has stable characteristic with simple constitution and the assembly and the adjustment can be possible. Furthermore, the optical path of the light beam from the laser element 2 is bent to be parallel with an optical disk 12 being an information recording medium by a non-polarizing reflection surface (m). Thus, the miniaturized optical head whose thickness is thin is obtained. |
