Video disk player optics.

The optics of a video disk player are described. The bandwidth and the playing time of a disk had been specified at 12 MHz and 30 min, respectively. A readout photodetector signal of high quality can be obtained with a well-corrected objective having a numerical aperture of at least 0.4. Some alternative readout modes and track formats are indicated. Methods for the generation of error signals for the radial and the vertical tracking are briefly discussed.