APPARATUS FOR REPRODUCING DIGITALLY CODED INFORMATION RECORDED ON AN OPTICALLY READABLE DISC-SHAPED RECORD CARRIER

摘要

26-2-1980 1 PHN 9669 "Apparatus for reproducing digitally coded information recorded on an optically readable disc-shaped record carrier". Apparatus for reproducing digitally coded information recorded on a disc-shaped record carrier in the form of optically detectable information areas arranged in accordance with a concentric or spiral track pattern. These information areas are unit areas. The apparatus comprises a filter which is tuned to a frequency f=V/L, V being the nominal tangential speed of the record carrier and L the nominal centre-to-centre distance of said unit areas. This frequency component has a frequency equal to twice the bit frequency of the coded information and is situated at a zero point of the power spectrum of said information, so that the extracted signal may be employed for the generation of a clock signal.