| 摘要 |
PURPOSE:To display a bar in the longitudinal direction, and a character in a frequency band, etc. in accordance with an input signal level, by synthesizing a level display signal obtained by converting the pulse duration of plural audio input signals, and a character display signal, and using its composite signal as a video signal. CONSTITUTION:An audio signal which has come in from an input terminal 1 is supplied to a pulse duration transducer 4 through plural filters 2 connected in parallel and plural rectifying and smoothing circuits 3, is synchronized with a vertical synchronizing signal of a video signal, and is converted to a pulse duration signal corresponding to its level. This pulse duration signal is time-divided in order in the horizontal scanning period by a multiplexer 5, is fetched serially, is supplied to an image receiving tube 8 through an adding gate 10, and is displayed as a bar graph. On the other hand, by a control signal from a CPU 14, an RAM 15 storing a character, a numeral and its display position is operated, a parallel signal from a character generator 16 is converted to a serial signal by parallel-series converting circuit 17, is supplied to the adding gate 10, and displays a character, a numeral, etc. |
