The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 01, 1980
Filed:
Mar. 20, 1978
Masahiko Koike, Hamamatsu, JP;
Nippon Gakki Seizo Kabushiki Kaisha, Namamatsu, JP;
Abstract
A musical sound controlling apparatus preferably incorporated into a music synthesizer type electronic music instrument and capable of generating a musical sound controlling signal in accordance with vocal signals or musical sound signals produced by musical instruments other than the music synthesizer type electronic musical instrument. The apparatus comprises a voltage-controlled filter whose frequency characteristics is controlled in accordance with a control waveform applied thereto and a control waveform generator which produces a control waveform varying with time in response to a trigger signal applied thereto. An external musical sound signal is applied to a switching circuit having a hysteresis characteristic through a rectifier circuit. The switching circuit is arranged to produce a stabilized trigger signal to be applied to the control waveform generator and have first and second different input switching levels for switching the output of the switching circuit. The first input switching level is set higher than the second input switching level. When a rising DC output voltage of the rectifier circuit exceeds the first input switching level the output of switching circuit is switched to produce a trigger signal and when a falling DC output voltage of the rectifier circuit falls below the second input switching level the output of switching circuit is switched back to the original state.