Apparatus for extracting envelope data from an input waveform signal and for approximating the extracted envelope data
US4958552A · kind A · utility
8Cited by
11References
24Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 14, 1989 |
| Grant date | Sep 25, 1990 |
| Priority date | — |
| Expiry date | Sep 14, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10H1/0575
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
An envelope extracting circuit extracts an envelope from the waveform sampled by a musical tone sampling circuit, and stores the envelope data into a memory. An envelope approximating circuit approximates the envelope data as stored in the memory by the function data such as linear or exponential function data. The original envelope is approximated by a limited number of function waveforms whose characteristics change at switching points.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.