| 摘要 |
PURPOSE:To set the S-N ratio of a reproduction signal so that the ratio is made always optimum in accordance with the relative scanning speed of light for reproduction and an optical recording medium without damaging the medium by the light for reproduction. CONSTITUTION:The power of light 8 for reproduction is increased in accordance with the increase of the scanning speed of the light 8 to an optical recording medium. At the same time, the return resistance R1-R5 of a pre-amplifier 26 is reduced in inverse proportion to the power of the light 8. |
