Musical note display device
US4510840A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1983 |
| Grant date | Apr 16, 1985 |
| Priority date | — |
| Expiry date | Dec 30, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10H2250/235
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
An input audio signal is AD converted into digital data which is processed by a central processing unit (CPU) in which Fast Fourier Transform (FFT) operation and power spectrum calculation are effected. Furthermore, spectrum data obtained in this way is processed to obtain a fundamental tone to determine the pitch of each sound of the input audio signal. After the pitch is determined, data indicative of a given pattern is produced so that a musical note is indicated at an appropriate position on a staff displayed on a screen of a display unit. Such data from the CPU is fed via a video display processor to a video RAM to be stored therein where the video display processor produces a video signal fed to the display unit in turn. Since the fundamental tone does not necessarily have the highest level within the spectrum of the input audio signal, various ways for accurate determination of the pitch are used. Furthermore, a reference pitch preset in the musical note display device may be changed so as to be equal to a reference pitch emitted from a musical instrument or the like by changing sampling frequency of sampling pulses fed to an AD converter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.