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:
Feb. 17, 1987
Filed:
Jul. 07, 1978
Akiyoshi Oya, Hamamatsu, JP;
Nippon Gakki Seizo Kabushiki Kaisha, Hamamatsu, JP;
Abstract
An electronic musical instrument capable of producing, by frequency modulation, a musical tone containing harmonic components of integer and non-integer orders at complicated ratios which change with time. In frequency modulation, amplitudes of carrier and side frequencies are preceded by a positive or negative sign depending upon a value of modulation index. By suitably setting the value of modulation index, phase inversion occurs in the side frequencies so that cancellation or augmentation of amplitude will occur between side frequencies of the same frequency. By utilizing this phenomenon and also the fact that the harmonic spectrum can be varied by varying the carrier and the modulating waves, the electronic musical instrument according to the invention produces a musical tone containing extremely complex harmonic components. An embodiment of the invention is disclosed in which a single sinusoidal carrier is frequency modulated by a single sinusoidal modulating wave to provide the frequency modulated wave as a musical tone signal. In this embodiment, the phase component of the carrier wave, phase component of the modulating wave, modulation index and amplitude coefficient are all time-variant values. In another embodiment of the invention, a single sinusoidal carrier is frequency modulated by two sinusoidal modulating waves. Other examples are also disclosed in which function waveforms other than a sine wave and containing harmonics are used as the carrier and modulating waves.