| 摘要 |
PURPOSE:To record information with high density and to reproduce the information with high resolution. CONSTITUTION:When the information is recorded to a recording medium 1, laser beams are generated by using together a laser beam source 7 emitting the laser beam with a short wave and the laser beam source 8 emitting the laser beam with a long wave, are converged to irradiate on the recording medium 1 through respective beam splitters 4, 5 and an objective lens 3. On the other hand, when the information is reproduced, the laser beam is generated with only the short wave laser beam source 7, the recording medium 1 is irradiated with the laser beam through the beam splitter 4 and the objective lens 3. Then, the reflected light beam is detected by a photodetector 6 and a regenerating signal is attained. At the time of recording the information, the power of the laser beam from respective beam sources are small since two laser beam sources are used, the wavelength of the laser beam generated from the beam source 8 is shortened than heretofore. Thus, a spot diameter is reduced. |
