| 摘要 |
PURPOSE: To impart a function to prevent accidental recording to the recording film itself by incorporating a photochromic material into the recording film. CONSTITUTION: The photochromic material is incorporated into the recording film of a DRAW type optical disk material. Compds., such as spiropyran, furkid or diallyl ethene, and others, which are in the decoloring state of the stable state and include the wavelength of a laser beam in the wavelength region to absorb light in a colored state are used as the photochromic material to be used here. Such DRAW type optical disk is irradiated with UV rays by using a mercury lamp, etc., by which the recording film is put into the colored state in recording information on the draw type optical disk. When the recording film is irradiated with the laser beam in this state, the temp. of the recording parts rise to the m.p. of the recording material or above and holes are formed, by which the information recording is performance. The recording film is irradiated with the laser beam of a low level and is put into the decoloring state in order to prevent the accidental recording. Since the sensitivity to the laser beam is low in this state, the information recording is not possible to perform by the ordinary laser beam. |
