| 摘要 |
PURPOSE:To accurately read the signal on a disc by photoelectrically detecting the components distributing other than the exit light conical body of a read objective lens. CONSTITUTION:The light emitted and condensed from a read objective lens 26 radiates the pits 31 on a disc 31. The light having been reflected and refracted after radiating the pits 31 assumes a distribution like 29, becoming such that the light also exists other than the exit light conical body. The distribution of the largest quantity of light other than the exit light conical body is when the pit depth is lambda/ 4. This quantity of light is detected with photoelectric detectors 32, 33. |
