| 摘要 |
PURPOSE:To display a peak level and a mean level by a luminance difference one bar, by taking logic of a pulse width signal corresponding to a peak level and a mean level of a frequency spectrum signal to obtain a video signal. CONSTITUTION:Audio signals which have come in from input terminals 1a, 1b are supplied to peak level detectors 3a1, 3b1 and mean level detectors 3a2, 3b2 through filters 2a, 2b. Outputs of each detector are converted to pulse width signals corresponding to its level by comparators 4a1, 4b1 and 4a2, 4b2, and after that, are supplied to multiplexers 8P, 8V, respectively, are time-divided in order in the horizontal scanning period, and are fetched serially. Subsequently, outputs of the multiplexers 8P, 8V are added through resistances R1, R2, and after that, are supplied to an image receiving tube through the adding gate. In this way, in the bar displayed on the image receiving tube, a peak level is displayed at low luminance and a mean level is displayed at high luminance. |
