| 摘要 |
PURPOSE:To realize a high recording density by making it possible to reduce a recording bit length to not larger than half a spot diameter of laser light. CONSTITUTION:A reproducing film 13 is formed of a metallic material which can be melted by laser light. A thickness of the film 13 is changed correspondingly to recording bits. The reproducing film 13 is melted and turned to liquid at a recessed part 13a only when the recessed part 13 agrees with a high- temperature central part of a laser spot. On the other hand, a projecting part 13b of the film 13 is not melted and maintained in a solid state at all times. Data is read by utilizing a difference of reflectivities of the solid and liquid. |
