| 摘要 |
PURPOSE:To increase the quantity of information to be recorded on an information recording medium by recording multilevel information by one recording unit at the optical information recording/reproducing system. CONSTITUTION:An optical information recording medium 2 is irradiated with a light emitted from a light source 1, its transmissive light is detected by a light receiving element 3 and data is identified by a data converting section 4 by its strength. At this time, the multilvel information over ternary is recorded based on density by one recording unit of the information recording medium 2, the strenghts of the transmissive lights detected from the information recording medium 2 are recognized step by step and the multilevel information is reproduced. |
