| 摘要 |
Apparatus and process for writing upon a video record and for reading the video information from the video record after the writing is complete, and the video disc structure so written. The apparatus includes a laser and an optical system which directs the laser beam to a prepared rotating disc. The disc has a very thin metallic coating. A first lens acts to diverge the laser beam so as to fill a miscroscope objective lens which focuses the beam to a small spot of approximately 1 mu m in diameter. The spot contains sufficient energy to melt the metallic surface coating on the disc. The surface tension of the molten metal makes it draw back leaving a hole. Video information in the form suitable for display with a T.V. monitor is applied to an F.M. modulator for forming an F.M. signal. The F.M. signal intensity modulates a laser beam passing through a Pockels cell-Glan prism combination. The series of holes forming the coating of the disc represent the F.M. signal. Since an F.M. signal characteristically is a frequency variable signal, the length of the holes and the distance between successive holes vary to represent the F.M. signal. |
