TV monitoring system for viewer response analysis - uses short coded interrogation signal trains inserted in program in response to state of viewer's keyboard

摘要

The remote monitoring system allows the state of a gp. of t.v. receivers to be determined remotely by connecting various loads to the electrical supply network in response to interrogate signals inserted into the t.v. programmes and in response to keys operated at a special keyboard accessible to the viewer. The keyboard is used by the viewer to express his opinion of the programme. The interrogate signals consists of a train of signals of short duration preceding the connection of the load. The signal train has an identification part and a part containing keyboard activation and memorising signals.