| 摘要 |
PURPOSE:To miniaturize an optical reproducer and to obtain a reproduced signal with high S/N, by dividing a reflected light flux into two parts by installing a wedge right after a focusing lens and obtaining a servo signal and a reproduced signal from each of the divided two light fluxes. CONSTITUTION:The reflected light flux given from a disk 6 is focused by a single lens 7 and divided into two parts by a wedge 10 to be led to photodetectors 13 and 14. The servo signals for focusing and tracking are obtained from the detectors 13 and 14, respectively. At the same time, a reproduced signal is obtained from the total sum of the outputs of detectors 13 and 14. Thus the number of optical elements can be reduced in an optical path of reflected light in comparison with the conventional optical system. As a result, not only the miniaturization but a low cost can be realized for an optical reproducer. Furthermore, the reproduced signal is obtained from the whole quantity of reflected light to increase the S/N. |
