| 摘要 |
<p>1530811 Recording and playback of television signals PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd 30 Sept 1975 [3 Oct 1974] 39940/75 Heading G5R In an optically-readable record of a television signal, the spatial frequency of areas 4, e.g. pits, along a track 2 represents a first carrier wave frequency-modulated with the luminance information while lateral undulation of the track 2 represents further carrier waves modulated with other information, the frequency of the first carrier wave being at least twice that of any of the further carrier waves. As described, the frequency of, the undulation represents chrominance information while its amplitude represents sound information, and a second undulation with a constant frequency an order of magnitude lower is superimposed on the first to facilitate track-following in playback apparatus of the type described in Specification 1,530,812.</p> |
