| 摘要 |
An optical data storage system is contemplated, one employing a data-modulated writing laser beam and a non-erasing reading laser beam of predetermined wavelength. Improved optical media for such systems are described, these characterized by multiple layers whose optical characteristics and thickness are chosen to accommodate a prescribed writing and reading energy and wavelength and so provide an "anti-reflection" condition for unrecorded portions of the medium and a relatively higher reflectivity for recorded portions. A preferred optical medium includes a highly reflective aluminum layer, a relatively transparent polymer spacer layer overlying the reflective layer, and an optical absorber (recording) layer overlying the spacer layer. Overcoating structure is specified in some detail; e.g., as a "soft pad" layer (e.g., fluoropolymer) on the absorber, with a "Hard" layer (e.g., radiation-cured acrylic) laid over the "soft pad" as an outer protective overcoat. Also, the "spacer" may be rendered as such a "soft pad". And "spiral" coating techniques for applying the "Hard" layer are described. |
