| 摘要 |
PURPOSE:To improve a shelf life and to permit recording at a high density and easy writing and reading out of information by recording the information and visible image by >=3 kinds of digital signals set in accordance with the difference in the existence amt. of blackened silver per specified area to a photographic emulsion layer on a base. CONSTITUTION:The information and if necessary the visible images by >=3 kinds of the digital signals set in accordance with the difference in the existence amt. of the blackened silver per specified area are recorded on the information recording medium consisting of the photographic emulsion layer 12 and a protective layer 13 on the transparent base (more preferably disk-shaped base) 11. A method for changing electric current in the case of semiconductor laser light and a method for applying AO modulation or EO modulation to the output of the laser light or using a liquid crystal shutter in the case of general laser light, etc. are usable as a method for changing >=3 values of light intensity. The reading of >=3 values of blackening levels is executed by detecting the transmitted light or reflected light of the spot-like incident light with a photodetector. |
