| 摘要 |
PURPOSE:To simplify the circuit by providing a pulse generating means of horizontal scanning frequency, writing all required information to constituted a synchronizing signal to a storage means and reading it in synchronizing with the horizontal scanning frequency. CONSTITUTION:A sole pulse formed by an input pulse generator 4 is inputted to a shift register 3, a pulse from a generator 4 with a clock pulse formed by an oscillating circuit 1 is circulated in the register 3 so as to form a horizontal scanning frequency. A counter circuit 21a counts a clock pulse from the circuit 1 by using the horizontal scanning period pulse to read a horizontal synchronizing pulse written in a memory 22a. The pulse is waveform-shaped by a latch circuit 23, the result is inputted to a composite decoder circuit 17 and a horizontal blanking pulse BLH stops the operation of the circuit 21a. The counter circuit 21b counts the horizontal synchronizing pulse, reads the vertical synchronizing pulse written in a memory 22b, a latch circuit 23b waveform-shapes it and inputs the result to the circuit 17. A prescribed synchronizing signal is obtained by synthesizing the horizontal and vertical synchronizing pulses at the circuit 17. |
