Victor Company of Japan, Limited

Zenju Ohtsuki

Yoshiaki Tanaka

Mamoru Inami

Tomohiro Mori

Akio Hasegawa

A level display device for audio signal comprises a plurality of bandpass filters having filtering bands of respectively different center frequencies, for band-dividing and filtering an input signal supplied thereto through an input terminal, a pulse width converter provided in correspondence with respective bandpass filters, for converting the input signal into a signal in synchronism with a vertical synchronizing signal of a video signal and having a pulse width in accordance with the level of the vertical synchronizing signal, a level indication signal producing circuit connected with outputs of the pulse width converter in parallel, for serially producing the converted pulse signal in synchronism with a horizontal synchronizing signal by successively time-dividing the converted pulse signal during a horizontal scanning period, a character indication signal producing circuit stored with information signals for displaying characters and the like, for serially obtaining a character indication signal in synchronism with a synchronizing signal of the video signal, and a video signal composing circuit driven by the video signal, for obtaining a video signal by composing an output of the level indication signal producing circuit and an output of the character indication signal producing circuit. Bars corresponding to the audio signal level in a vertical direction, characters, and the like, are composed and displayed on a screen of a picture tube, by the outputs of the level indication signal producing circuit and the character indication signal producing circuit.

Level display device for audio signal

An automatic recording bias current setting apparatus comprises a bias current generating circuit for generating a bias current with varied level of the bias current, a testing signal generating circuit for generating two kinds of testing signals having different mid and high frequencies of an audio signal, by independently varying the levels of the testing signals, a recording and reproducing circuit for recording the two kinds of testing signals with the bias current onto a magnetic recording medium and reproducing the same, and a bias current detecting circuit for detecting the level of a bias current. The recording and reproducing circuit repeats an operation in which the two kinds of testing signals are recorded onto the magnetic recording medium and then reproduced with independently varied levels of the two kinds of testing signals under the same bias current obtained from the bias current generating circuit, for each of the different varied bias currents. The bias current detecting circuit detects respective reproduced output levels of the two kinds of testing signals with respect to the different bias currents, to detect a bias current level at a point where a difference between respective maximum reproduced output levels becomes equal to a preset predetermined value.

Automatic recording bias current setting apparatus

A level display device for audio signal comprises a plurality of bandpass filters having filtering bands of respectively different center frequencies, for band-dividing and filtering an input signal supplied thereto through an input terminal, a level indication signal producing circuit for converting the input signal into a signal in synchronism with a horizontal synchronizing signal of a video signal and having a pulse width in accordance with the level of the horizontal synchronizing signal, and serially obtaining the converted signal in sychronism with a vertical synchronizing signal of the video signal by successive time-division carried out during a vertical scanning period, a character indication signal producing circuit stored with information signals for displaying characters and the like, for serially obtaining a character indication signal in synchronism with a synchronizing signal of the video signal, and a video signal composing circuit driven by the video signal, for obtaining a video signal by composing an output of the level indication signal producing circuit and an output of the character indication signal producing circuit. The level display device composes and displays bars in a horizontal direction corresponding to the audio signal level, characters, and the like, on a screen of a picture tube, by the outputs of the level indication signal producing circuit and the character indication signal producing circuit.

Display device for displaying audio signal levels and characters

A maximum output level automatic measuring apparatus comprises a testing signal generating circuit for generating a plurality of testing signals having different frequencies, by independently varying respective levels of the testing signals, a recording and reproducing circuit for recording the plurality of testing signals from the testing signal generating circuit onto a magnetic recording medium, and reproducing the recorded testing signals, a level detector for detecting reproduced levels of the plurality of testing signals from the recording and reproducing circuit, and a display device for displaying a maximum output level curve according to reproduced levels detected at the level detecting circuit. The level detector detects that reproduced levels of the plurality of testing signals have reached predetermined values preset with respect to the respective testing signals. The display device comprises a display screen having a frequency axis and a level axis, and independently displays the reproduced levels which reached the predetermined values detected by the level detector for each of the frequencies.

Growing community of inventors

Tokyo, Japan

Zenju Ohtsuki