| 摘要 |
PURPOSE:To prevent overheating in case of recording, by selecting a wavelength of an optical beam so that a reflection factor of light from a material becomes large, in case of irradiating a recording optical beam. CONSTITUTION:Recording is executed at a longer wavelength side than a reference wavelength by which a reflection factor becomes the same before and after recording, and an erasion is executed at a lower wavelength side. By providing a laser light source system 10 for generating a laser beam of at least two or more wavelengths, and irradiating a disk 40 supported by a disk supporting body 50 through a beam splitter 20, the recording contents on a disk board are changed (recorded or erased) or read out, and a signal is reproduced by a detector 30. In this way, overheating in case of write can be prevented. |
