| 摘要 |
PURPOSE:To miniaturize the above element by providing an incident face and exit face of light on an objective lens and providing a reflecting surface between the exit face and the exit face and forming the element integrally. CONSTITUTION:The optical element 1 for optical disks has the exit face 1A and incident face 1B of the aspherical face and is set with the reflecting surface 1C between the exit face 1A and the incident face 1B, by which this element is integrated. The optical axis 8 of a laser beam is perpendicularly bent by the reflecting surface 1C when the laser beam is made incident on the optical element 1 having the incident surface, exit surface and reflecting surface of the aspherical faces. The laser beam is simultaneously condensed onto an optical disk 5 by the aspherical face parts 1A, 1B. This beam travels backward in the same route and arrives at a beam spliter 3. The laser beam transmits the beam splitter 3 and is condensed to a signal reading part 7 by passing a concave lens 6. A moving part 4 moves correpsondingly when the optical disk 5 moves. The misalignment of the focus of the laser beam is thus prevented. The optical element is miniaturized in this way. |
