Variable frequency generator for polyphonic electronic music system
US4122744A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 15, 1977 |
| Grant date | Oct 31, 1978 |
| Priority date | — |
| Expiry date | Aug 15, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S84/04
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
Simultaneously played notes on a keyboard are automatically provided with different voice timbres. The assignment of voices to notes is by relative frequency-scale position within the chord. If four or more notes are played, the notes are scanned along the musical scale and the three lowest notes played and the highest note are sounded in different voices with the solo voice assigned to the highest note. Assignment of voices occurs automatically when fewer than four keys are played. One form of the system combines time multiplexed keying with priority coupling of the keying information to a plurality of voltage controlled oscillators through sample-and-hold memory circuits. Each oscillator has its own tone voicing circuits. In another preferred all-digital embodiment, the time division multiplex digital logic signals representative of the played keys are applied instead to a memory circuit and a comparator circuit. If the information stored in the memory from the previous scan cycle is the same as the information of the present cycle, thereby indicating no change in played keys, the comparator provides an enabling signal to a monostable and enable logic circuit. A priority selector…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.