| 摘要 |
<p>A mold for use in forming at least the video information layer of a video disc is disclosed. The mold includes a body having a substantially flat upper surface with discontinuities out of the plane of the surface, the discontinuities being separated by a flat portion of the surface. The discontinuities and the flat portions are arranged in a video information track, which track is substantially circular. Each discontinuity has a constant radial dimension and a constant maximum dimension in the direction perpendicular to the flat surface. The length of each discontinuity in the circumferential direction and the corresponding separation between adjacent discontinuities represents the stored information. The discontinuities may take the form of depressions in the surface or protrusions above the surface.</p> |
