APPARATUS FOR READING A DISC-SHAPED RECORD CARRIER

摘要

1 PHN 9248 An apparatus for reading a disc-shaped record carrier on which per track circumference one picture of a colour television signal is recorded. The signal being read is converted to a standard PAL colour television signal. The apparatus comprising a command device which by applying command signals to control means can produce a jumpwise radial change in the scanning position on the record carrier, so as to enable the scanning sequence of the recorded pictures to be changed. In order to maintain a standard PAL colour television signal in the case of a changed scanning sequence, the apparatus comprises a correction device for the chrominance signal. This correction device is controlled by the command device and comprises a mixing circuit for mixing the chrominance signal with a reference signal of twice the chrominance subcarrier frequency during time intervals prescribed by the command device, and phase correction means for introducing a phase shift of 0.degree., 90.degree., 180.degree. or 270.degree. in thechrominance signal in accordance with a pattern defined by the command device.