| 摘要 |
<p>This invention relates to an improvement in a video disc playback system which derives video signals from a track on a video disc using a light source and an optical path to a lens system which is supported by an air bearing at a predetermined spacing from the surface of the disc. In the prior art, it has been extremely difficult to maintain an exact spacing between a read head and a video disc, and the variations in such spacing result in the reading beam going in and out of focus, producing a poor quality picture. The present invention maintains constant spacing between the read head and the video disc by providing a read head which is yieldably mounted on a head support and adapted to be maintained in close proximity to the video disc surface. A fluid bearing support member is coupled to the read head and has a surface adapted to create a fluid hearing between the fluid bearing support member and the rotating video disc. An adjustable bias assembly, responsive to the radial position of the read head, applies a varying force to the read head in the direction of the disc to achieve the desired predetermined spacing between the head and the disc substantially independent of radial position of the head.</p> |
