US 4,358,787 A · Digital process for controlling the correct reproduction of a composite television signal and a device for implementing said process

Abstract

A digital process for controlling the correct reproduction of a composite television signal and in particular of a composite color television signal comprising sequential-type chrominance signals, transmitted or recorded on an information-carrying medium such as a videodisk in which binary-coded pulsed signals are inserted during available intervals of the line scanning return, the binary value of these pulsed signals representing a particular state to be controlled. This value is detected during the process reproducing the composite television signals to make the particular state to be controlled dependent on this value. A first coded pulsed signal may be used for identifying the two components of the chrominance signals. A second coded pulsed signal may be used for identifying the face read of a transparent videodisk having information recorded on both its faces.

Claims9

Dependent claims

A digital process for checking the correct reproduction of a composite television signal transmitted or recorded on an information-carrying medium at the timing of the scanner of the lines of an image, comprising the steps of:

inserting at least binary-coded pulse signals during the recording or transmission of said composite signal at a predetermined time during the return intervals of said line scanning wherein the succession of logical values assumed by said signal determines a pre-established sequence of binary states to be checked;
detecting said succession of values during the reproduction of said composite signals;
correlating said detecting values with said pre-established sequence of binary states to be checked so that said sequence is dependent upon said succession of values;
and
modifying said correlation so that the dependency of said sequence upon said succession of values is insensitive to consecutive alternations of said pre-established sequence less in number than a predetermined threshold number.

2 more elements

A device for checking the correct reproduction of a composite television signal transmitted or recorded on an information-carrying medium at the timing of the scanning of the lines of an image comprising:

means for inserting at least one binary-coded pulsed signal at a predetermined time during the return intervals of said line scanning during the recording and transmitting process whereby said pulsed signals have a succession of logical values which represent a pre-established sequence of binary states to be checked;
reading and storing means for storing said coded pulsed signals;
first shift register means having a predetermined number of stages;
logic circuit means for repeatedly introducing said coded pulsed signals recorded in said storage means into said first shift register means whereby the repeated introduction of said pulses is sequenced with said line scanning timing;
detection circuit for receiving at its inputs the outputs of said first shift registers means and outputting a pulse for reinitializing said first shift register means when all of said outputs of said stages are at the same logic value.

2 more elements

Dependencies are inferred from the claim text.

Digital process for controlling the correct reproduction of a composite television signal and a device for implementing said process

Life of this patent

Digital process for controlling the correct reproduction of a composite television signal and a device for implementing said process

Life of this patent

Abstract

Claims9