Demultiplexer for providing a color television signal having an increased image frequency

Claim 1

A demultiplexer for a combined color television signal composed of a plurality of first components containing luminance information and a plurality of second components containing chrominance information, the television signal initially being in a form such that the second components alternate in time with the first components, said demultiplexer comprising: first shift register means having a plurality of register locations, a serial input connected to receive the television signal in its initial form, parallel inputs and outputs and a serial output; second shift register means having a plurality of register locations parallel inputs and a serial output; memory means connected to said parallel inputs and parallel outputs and having a plurality of individually addressable memory locations arranged in rows and columns; and sequence control means including a plurality of address counters connected to said memory means so that each said counter independently addresses a selected group of memory locations, said counters including two write address counters operable for writing each component of the television signal into a respective group of memory locations from said parallel outputs of said first shift register means, and two read address counters operable for reading each first component of the television signal from said memory means to said parallel inputs of one of said shift register means and for reading each second component of the television signal from said memory means to said parallel inputs of the other one of said shift register means, whereby the first components of the television signal are supplied in succession to said serial output of said one register means and the second components of the television signal are supplied in succession to said serial output of the other one of said register means.