| 摘要 |
PURPOSE:To record and erase information at high speed and, at the same time, to prevent occurrence of insufficient erasing of information, by projecting both spots of natural light and laser beam upon an optical recording medium, with the natural light spot preceding the laser beam spot in the moving direction of the medium. CONSTITUTION:An optical means which projects a spot of laser beam (i) and spot of natural light (n) which is larger than the spot of laser beam closely to each other upon an optical recording medium 14 is provided and both spots are projected upon the medium 14 under a condition where the spot of the natural light (n) precedes the spot of laser beam (i) in the moving direction of the medium 14. Since sufficiently high output one can be obtained for the light source of the natural light, the energy density of the natural light spot can be made sufficiently high on the recording medium and the spot of the natural light (n) can make preheating works by heating wide areas preceding the laser beam spot on the optical recording medium 14. Therefore, the temperature raising time can be made shorter and high-speed recording and erasing of information or recording, while erasing is made, can be realized. Moreover, since heating can be performed at the high energy density, all information to be erased can be erased completely at the time of erasing.
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