| 摘要 |
<p>A medium in tape form for laser recorded optical information featuring a gelatin layer (25) having a thin black crust (26) at the top of the layer. The crust (26) is formed by developed black filamentary silver particles within the top 0.5 micron of a gelatin colloid matrix. The remainder of the colloid matrix is substantially clear gelatin and a reflective metallic layer (24) is disposed below the gelatin. The tape (13) may be disposed on reels (31) and may be pre-patterned during formation of the crust with indicia, such as servo track guides or timing marks (Figs. 5-7). User data (18, 20) may be recorded by modification or by displacing the black silver particles in the crust with a laser (21) to expose the reflective underlayer. A laser (143) or other light source is used to read data on the medium with optical contrast between the black surface and the reflective metallic layer underlaying the gelatin layer which can be observed in the recorded spots.</p> |
