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:
Sep. 28, 1976
Filed:
Sep. 16, 1975
Nobuharu Obayashi, Hamamatsu, JA;
Hikaru Hashizume, Hamamatsu, JA;
Noriji Sakashita, Hamamatsu, JA;
Seiji Kameyama, Hamamatsu, JA;
Sadaaki Ezawa, Hamamatsu, JA;
Toshio Kugisawa, Hamamatsu, JA;
Yutaka Washiyama, Hamamatsu, JA;
Tatsunori Kondo, Hamamatsu, JA;
Hironori Watanabe, Hamamatsu, JA;
Kabushiki Kaisha Kawai Gakki Seisakusho, Hamamatsu, JA;
Abstract
An apparatus for forming a musical-tone waveform for an electronic musical instrument characterized in that at least one cycle of a musical-tone waveform, which it is desired be produced, is divided in amplitude by dividing lines at equal intervals and sampling points on a time axis are determined from respective crossing points between the waveform and the dividing lines and the distance between the initial and the final sampling points is represented by an appropriate number of pulses so that each sampling point may be represented by a pulse number. There is further provided a memory circuit wherein each sampling point, that is, the pulse number thereof is set up in the form of a digital signal. Additionally, there is a set up in the form of a digital signal a tendency such as increase, decrease or equal at each sampling point with reference to the preceding sampling point. An envelope setting device is used wherein the envelope of a muscial-tone waveform, which it is desired be produced, is subjected to sampling and the analog amount of each sampling point is set up in the form of digital signal. An accumulatively adding device is employed whereby the output digital signal of the envelope setting device is accumulatively added to or subtracted from the output digital signal of the memory circuit. The accumulatively adding device is connected at its output terminal to a D-A converter for converting its output signal into an analog signal.