Television system using a marking code superimposed on the picture
First Claim
1. A television system comprising a means for superimposing a marking code on one of the pictures to be televised and a decoder able to detect the presence of this code in the pictures, wherein the said marking code is formed by a first vertical strip constituted by a periodic sequence of alternately white and black areas, said strip being positioned along one of the lateral edges of the picture and by a second vertical strip constituted by a sequence of white or black areas, each extending over a height equal to the period of said sequence formed by the first strip, said second strip being located along the other lateral edge of the picture, the video signal corresponding to a picture having received such a code thus incorporating black or white signals located at the start and finish of a scanning line, and wherein the decoder comprises a circuit for detecting, in the video signal which it receives, the presence of white and black signals located at the start and finish of the line and for recognising, on the basis of the thus detected signals, the presence of said code and for transmitting a control order.
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Accused Products
Abstract
Television system using a marking code superimposed on a picture.
According to the invention, this code is constituted by a strip located in the right-hand part of the picture and formed by a periodic sequence of white and black areas constituting a clock and by a strip located in the left-hand part of the picture and formed by a sequence of white or black areas constituting the actual code. A decoder detects the presence of clock signals and compares the code received with stored codes.
132 Citations
6 Claims
- 1. A television system comprising a means for superimposing a marking code on one of the pictures to be televised and a decoder able to detect the presence of this code in the pictures, wherein the said marking code is formed by a first vertical strip constituted by a periodic sequence of alternately white and black areas, said strip being positioned along one of the lateral edges of the picture and by a second vertical strip constituted by a sequence of white or black areas, each extending over a height equal to the period of said sequence formed by the first strip, said second strip being located along the other lateral edge of the picture, the video signal corresponding to a picture having received such a code thus incorporating black or white signals located at the start and finish of a scanning line, and wherein the decoder comprises a circuit for detecting, in the video signal which it receives, the presence of white and black signals located at the start and finish of the line and for recognising, on the basis of the thus detected signals, the presence of said code and for transmitting a control order.
Specification