JPS6447186A - Signal generator for recording teletext signal - Google Patents

Abstract

PURPOSE:To surely extract a TELETEXT signal even when a jitter exists at the time of recording by designating a line preceding the line to which character information are overlapped, and overlapping a pilot signal in synchronizing with a clock line. CONSTITUTION:For an inputted video signal, a synchronizing signal is separated in a synchronizing signal separating circuit 46. For the synchronizing signal, an equalizing pulse is removed by a 1/2 pulse killer 47 and the signal is inputted through a pulse delay device 48 to a burst gate 42. On the other hand, in the synchronizing signal, only a vertical synchronizing signal is separated by a vertical synchronizing signal separating circuit 49 and the reset input of a counter 50 is obtained. The counter 50 counts the line to which the pilot signal is inserted with use of the vertical synchronizing signal as a reference, and an inserting position is exactly determined by an inserting position preparing circuit 51 from the output. On the other hand, the color burst of the video signal is extracted through a BPF41 and the gate 42 as the color burst, and obtained as 2.86MHz in a PLL circuit 43. Then, it is overlapped through a gate 45 to the video signal by an adder 59.