| 摘要 |
PURPOSE:To display a horizontal direction bar and a character corresponding to an input signal level on the same picture, by generating a video signal from an output which has converted plural audio input signals to pulse width signals, and a signal corresponding to a character, etc. CONSTITUTION:Audio signals which are fed from input terminals 1a, 1b are supplied to pulse width transducers 4a, 4b through plural filters 2a, 2b connected in parallel, and plural rectifying and smoothing circuits 3a, 3b, are synchronized with a horizontal synchronizing signal of a video signal, and are converted to a pulse width signal corresponding to its level. This pulse width signal is time- divided in order in the vertical scanning period by a multiplexer 5, and is fetched serially, and it is supplied to an image receiving tube through an adding gate 10, and is displayed as a bar graph. On the other hand, in accordance with a control signal from a central control processor, an RAM storing a character and its display position is operated, a parallel signal from a character generator is supplied to the adding gate 10 through a parallel-series converter, and a character, a numeral, etc. are displayed. |
