Music – Instruments
Patent
1979-12-06
1981-04-07
Witkowski, Stanley J.
Music
Instruments
84 124, 84DIG4, 84DIG10, G10H 104, G10H 108
Patent
active
042598885
ABSTRACT:
A digital technique for triangular musical waveform generation is disclosed. A musical scale value corresponding to a selected note is repetitively added to produce an ascending series of non-consecutive numbers which is stored in a latch. A carry output from the limited modulus latch is used to switch a flip-flop which then enables an inverter to reverse the slope of the number series. Alternating reversals produce a rising and falling numerical staircase of controllable slope. This can be directly converted into a smooth triangular waveform, or alternatively it can be used as a series of memory addresses for table look-up purposes. The triangular waveform may be symmetrical, or it may have a controlled degree of asymmetry. Duplicate triangular waveforms with a small frequency mismatch may be used to produce a chorus effect. Or plural triangular waveforms with octavely related frequencies may be used as footages related to a single note, again with a slight frequency mismatch for chorus purposes. The frequency mismatch is effected by introducing extra pulses into the ascending number series by means of a synchronized carry input to the latch. When used in the table look-up mode, the invention permits great savings of waveshape memory capacity by the use of half-cycle and quarter-cycle symmetry. The latter feature is achieved by the use of a format translation from binary offset to sign-magnitude notation for table look-up purposes, after which the resulting waveshape is converted back into the original binary offset notation. The table look-up approach is also used in conjunction with plural triangular waveforms, by virtue of time-division multiplexing.
REFERENCES:
patent: 3763364 (1973-10-01), Deutsch et al.
patent: 3809786 (1974-05-01), Deutsch
patent: 3828109 (1974-08-01), Morez
patent: 3994195 (1976-11-01), Chibana et al.
patent: 4014238 (1977-03-01), Southard
patent: 4103582 (1978-08-01), Chibana
patent: 4116103 (1978-09-01), Deutsch
patent: 4119005 (1978-10-01), Kondo et al.
patent: 4133241 (1979-01-01), Niimi et al.
patent: 4159527 (1979-06-01), Yahata et al.
patent: 4186637 (1980-02-01), Swain et al.
Kail Jack
Kransdorf Ronald J.
Norlin Industries, Inc.
Witkowski Stanley J.
LandOfFree
Tone generation system employing triangular waves does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Tone generation system employing triangular waves, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tone generation system employing triangular waves will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-283716