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. 23, 1997
Filed:
May. 09, 1995
Yoichiro Ogai, Hamamatsu, JP;
Masahiro Shimizu, Hamamatsu, JP;
Yamaha Corporation, , JP;
Abstract
A pitch-asynchronous-type musical tone creating apparatus, provided for an electronic musical instrument, comprises at least a waveform memory, a low-pass filter and an interpolation section. Waveform samples, stored by the waveform memory, are sequentially read out, so that the interpolation section performs interpolation process on the waveform samples to create interpolation samples. Musical-tone parameters, such as a tone-color characteristic and an envelope characteristic, are imparted to the interpolation samples so as to create musical-tone samples. When performing reading operations on the waveform memory at a high speed which causes skipping of the reading operations, certain frequency components, which cause occurrence of folding noises, are incorporated into the interpolation samples. Those frequency components are removed from the waveform samples, read from the waveform memory, by the low-pass filter whose cut-off frequency is determined responsive to a frequency number. The frequency number is set responsive to a pitch designated for a musical tone to be produced. The low-pass filter is activated only when the frequency number is larger than a certain number so that skipping of the reading operations may occur. The musical-tone samples are accumulated with respect to a plurality of channels which operate in a time-division manner, so that musical tone signals, corresponding to musical tones to be produced, are created based on the musical-tone samples accumulated.