| 摘要 |
PURPOSE:To reproduce the recorded information of high density with high resolution, high reliability and accurate timing by using a recording medium having different reflection factors and phases of reflected light between a record area and a non-record area to detect the difference of intensity between reflected beams given from the surface of the recording medium as well as the overall intensity and to perform the arithmetic processing. CONSTITUTION:The information is recorded on a recording medium 7 having different reflection factors and phases of reflected light between a record area and a non-record area by the intensive laser light delivered from a semiconductor laser 2 which is actuated by a laser driving circuit 1 via a collimator lens 3, a polarized beam splitter PBS4, a lambda/4 plate 5 and a focusing lens 6. The weak laser light given from the laser 2 is focused on the medium 7, and this reflected light is reflected by the PBS4 and made incident to a 2-split photodetector 8. The output of the detector 8 has an addition of the difference output and the overall output through a correcting adder 14 to obtain a reproduction signal 104 via an addition amplifier 10, a differential amplifier 11 and a level controller 12. Thus it is possible to perform reproduction with high resolution, high reliability and accurate timing. |
