| 摘要 |
A television picture on a television test and measurement instrument adds a vertical sweep generator, and if necessary a horizontal sweep generator, to a conventional instrument. Vertical and horizontal sweep triggers are generated by a sync processor of the instrument from an input video signal to drive the respective sweep generators. A vertical sweep signal from the vertical sweep generator is input to a switch together with the input video signal. The output of the switch drives a vertical deflection circuit such that when the input video signal is output from the switch the instrument is in standard waveform monitor mode, and when the vertical sweep signal is output from the switch the instrument is in a picture mode to provide a raster scan image of the input video signal on a display. Also the horizontal sweep signal may be input to the switch such that the horizontal and vertical deflection circuits are driven by component signals from the input video signal in a vectorscope mode, and by the horizontal and vertical sweep signals in the picture mode. For apparent simultaneous display of the measurement signal and the video picture, switching occurs at a field or frame rate.
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