| 摘要 |
PURPOSE:To record or reproduce disks having different recording wavelengths by a common recorder or reproducer by providing a shutter for selectively passing lasers of long and short wavelengths that are spectrally separated, and an objective lens for condensing and emitting the selected light to a recording medium. CONSTITUTION:A shutter 21 is provided in a spectral optical path. In the case of recording, the shutter 21 formed with a through hole 21a is slid in a direction B to shield an optical path of a short wavelength laser light and to allow recording by a long wavelength laser light. In contrast, it is slid in a direction A to shield an optical path of a long wavelength laser light and to allow recording by a short wavelength laser light. Both the lights are condensed and emitted by an objective lens. Further, in the case of reproducing, the shutter 21 is disposed in a predetermined state. Both the lights are emitted to the disk, and reflected. Thus, two types of the disk having different recording wavelengths can be recorded or reproduced by the same recorder or reproducer. |
