Circuit for blending anologue signals and alphanumeric characters into the picture screen of a television receiver

Abstract

Abstract The insertion circuit consists of a clock generator (2), one counter (3, 5) or one monostable flipflop each and associated decoders (4, 7) for determining the location of insertion in the horizontal and vertical direction, the decoders (4, 7) selecting addresses of a memory (ROM) (10) in which the various analogue and alphanumeric characters to be inserted are stored. So that the insertion circuit simultaneously reproduces several analogue voltages by multiple utilisation and causes information parts of previous insertions to be masked out, an additional vertical counter (11) is provided which, after a presettable number of input pulses, outputs a pulse to a bistable flipflop (12) which can be reset by the vertical synchronisation pulses. One output of the bistable flipflop (12) switches on the second analogue display (UB) to be inserted via an electronic switch (13) whereas the other output of the bistable flipflop (12) at the same time inhibits alphanumeric information coming from the memory (10) during the period of this additional insertion. <IMAGE>

Inventors

• 👤 Bodo Arendt
• 👤 Walter Dipl.-Ing. Späth

Bibliographic Details