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:
Oct. 12, 1993
Filed:
Sep. 04, 1991
Yamaha Corporation, Hamamatsu, JP;
Abstract
There are provided a waveform generating section for generating waveform sample data at a frequency corresponding a designated pitch, a coefficient generating section for generating n coefficients that correspond to a desired interpolation characteristic, a characteristic-controlling section for changing the coefficients to be generated in the coefficient generating section so as to variably control the interpolation characteristic, and an interpolation operation section for operating the coefficients with n digital waveform sample data generated sequentially from the waveform generating section and synthesizing operated data to produce one sample data. With this arrangement, it becomes possible to control the interpolation characteristic and therefore a resultant filter characteristic in accordance with a desired mode, when generating a tone signal of a smooth waveform by waveform interpolation operation utilizing digital filter operation. For example, the interpolation characteristic can be controlled in accordance with a pitch or tone range so that a filter characteristic to be obtained as the result of the interpolation operation can be prevented from shifting as a pitch or tone range changes. Further, by controlling the interpolation characteristic in correspondence with a specific tone range, such characteristic can be established as to reliably eliminate an aliasing noise.