| 摘要 |
PURPOSE:To ensure the steady recording and reproduction of the information, by installing with an inclination the lambda/4 plate after the rear cylindrical lens. CONSTITUTION:The lambda/4 plate 6 is installed at the back of convex cylindrical lens 7, and thus reflected light l3' sent from lens 7 is not irradiated to optical detector 11. This is due to the fact that the reflected light from lens 7 does not pass through plate 6 and thus transmits through polarized beam splitter 5 without being reflected toward detector 11. Thus the floating light from lens 7 can be prevented, but the consideration must be given to the reflected light from plate 6 itself. No problem occurs to the reflected light from front surface H of plate 6, but reflected light l4' from back surface I is irradiated to detector 11 to be turned into the floating light. In this connection, plate 6 is tilted by angle theta in order to avoid detection of light l4'. The angle theta is set preferably 2-5 deg.. |
