| 摘要 |
PURPOSE:To obtain a system of recording data by irregularities on the surface of a medium and having erasing and rewriting functions by a method wherein the irregularities are formed on a thin film according to a quantity of energy or an irradiation time by forming a slow-cooling or quenching state after a laser irradiation. CONSTITUTION:A thin film 31 has a uniform amorphous structure as an initial state, and thereon an uncontinuous crystalline part, i.e. a recessed part, is formed by a latent image forming means 20. The latent image forming means 20 consists of two laser irradiators and an optical system for irradiating the laser to a required position on the thin film 31. The laser includes a smoothing laser 21 and an image forming laser 22. The smoothing laser 21 emitted in a linear form uniformly irradiates the surface of the thin film 31 by the rotation of a thin film drum 30. The image forming laser 22 emitted in a dot form linearly scans the surface of the thin film 31 by the rotation of a polygon mirror deflecting device and irradiates a required position. In the forming of a latent image, the image forming laser 22 is irradiated succeeding to the irradiation of the smoothing laser 21, whereby the irradiated part is gradually cooled to form a crystalline structure, i.e. a recessed part. The recessed part is required to be several micrometers in depth. |
