Field number conversion circuit.

摘要

In a field number conversion circuit the mutual positions of the horizontal and vertical synchronizing signal pattern in a field of the television signal to be converted are measured by means of a measuring circuit (201) and these mutual positions are adequately transferred by means of a coupling circuit (203) to a corresponding field in the converted television signal (Fig. 2). Reading the field memories (125, 127) used during the conversion operation is preferably effected at a clock frequency (at 53) which is not coupled to the clock frequency (at 23) used during the writing operation (Fig. 1).