| 摘要 |
PURPOSE:To enable stable observation, by triggering an oscilloscope with every horizontal synchronizing signal only during te selected section and picturing the waveform of a television signal of the section on the scope screen. CONSTITUTION:A television signal is applied to an input terminal 2 as the X axis input of an oscilloscope 3, and it is applied to a luminance separation circuit 6 with the polarity as it is or its inversion to detect the first position reference pulse after the vertical synchronizing signal. A flipk-flot 7 is set with the reat edge of the detection output. The vertical synchronizing signal is detected at a synchronizing separation circuit 8 and the rear edge resets the flip-flop 7. The output of the flip- flop 7 is inputted to a counter circuit 11 via a differentiation circuit 9 and AND gate 10 to start the count of a horizontal synchronizing signal. A count circuit 11 outputs outputs eA-eE. They gates the horizontal synchronizing signal and applies it to an external trigger terminal of the oscilloscope 3. |
