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:
Aug. 21, 1979
Filed:
Feb. 01, 1978
Ikutaro Kakehashi, Osaka, JP;
Roland Corporation, , JP;
Abstract
A device for producing a chorus effect in an electronic musical instrument. An electronic delay circuit and a non-modulating amplifier means are coupled in parallel and the outputs are mixed in a mixing amplifier. A carrier oscillator is coupled to the delay circuit for controlling the time delay of the delay circuit according to the frequency of its output, and normally oscillates at a relatively high frequency in the range of 80-100 KHz. A modulation signal generator is coupled to the carrier oscillator for frequency modulating the carrier oscillator toward lower oscillating frequencies, and a control signal generator is coupled between the input to the delay circuit and the modulation signal generator for detecting the musical tone signal input to the delay circuit and producing a control signal only when a musical tone signal input is detected. The delay time of the electronic delay circuit is thus modulated only when a musical tone signal input exists and when the carrier oscillator is not subjected to frequency modulation when no musical tone signal exists, the noise in the delay circuit is not modulated and any jarring effect in the output thereof is substantially eliminated.