US3828109A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chorus generator for electronic musical instrument
Assignee: Chicago Musical Instrument Co
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Filing: 1973-02-20
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Granted: 1974-08-06
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Expires: 1993-02-20
Abstract
Abstract An electronic musical instrument has a plurality of frequency synthesizers for separately generating the musical tones of each octave. Each of the frequency synthesizers is supplied with a train of clock pulses having a pulse repetition rate which is a multiple of the frequency of the highest musical tone generated by such frequency synthesizer. The pulse train applied to the frequency synthesizers for the highest octave is derived from a clock pulse source, and the pulse train applied to each of the other frequency synthesizers is derived from the pulse train supplied to the frequency synthesizer for the next higher octave, by dividing the pulse repetition rate thereof by a factor which differs slightly from two. As a result, corresponding musical tones of successive octaves are not locked in phase relationship but have frequencies which differ slightly from pure harmonics so as to present a generally rolling or moving chorus effect when such tones are reproduced simultaneously.
Inventors
- 👤 E Morez
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:18
CPC Classifications
G; G10; G10H; G10H1/00; G10H1/02; G10H1/06; G10H1/08; G10H1/10; Y; Y10; Y10S; Y10S84/00; Y10S84/04
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
64 words
In an electronic musical instrument, the combination comprising a pair of frequency synthesizer, a source of clock pulses connected to one of said frequency synthesizers, and frequency divider means connected with said source for dividing the pulse repetition rate of said clock pulses by a factor which differs slightly from 2, said frequency divider means being connected to another one of said frequency synthesizers.
Claim 2
Dependent Claim
64 words
In an electronic musical instrument, the combination comprising a pair of frequency synthesizer, a source of clock pulses connected to one of said frequency synthesizers, and frequency divider means connected with said source for dividing the pulse repetition rate of said clock pulses by a factor which differs slightly from 2, said frequency divider means being connected to another one of said frequency synthesizers.
Claim 3
Dependent Claim
56 words
Apparatus according to claim 1 including a third frequency synthesizer, and a second frequency divider means connected with the first frequency divider means for dividing the pulse repetition rate furnished by said first frequency divider circuit by a factor which differs slightly from 2, said second frequency divider means being connected to said second frequency synthesizer.
Claim 4
Dependent Claim
96 words
Apparatus according to claim 1 wherein said frequency divider means comprises a flip-flop for dividing the pulse repetition rate of said clock pulses by a factor of 2, an exclusive OR gate having one input connected to said flip-flop, an oscillator for generating a signal having a lower frequency than said clock pulses means for connecting, said oscillator with a second input of said exclusive OR gate for causing said exclusive OR gate to produce a train of pulses at its output having a pulse repetition rate which differs slightly from the output of said flip-flop.
Claim 5
Dependent Claim
42 words
Apparatus according to claim 3, including a D-type flip-flop having its D input connected to said oscillator and its clock input connected to said source, the output of said D-type flip-flop being connected to said second input of said exclusive OR gate.
Claim 6
Dependent Claim
151 words
Apparatus according to claim 2, wherein said first frequency divider means comprises a first flip-flop for dividing the pulse repetition rate of said clock pulses by a factor of 2, a first exclusive OR gate having one input connected to said first flip-flop, an oscillator for generating a signal having a lower frequency than said clock pulses, means for connecting said oscillator with a second input of said first exclusive OR gate, and said second frequency divider means comprises a second flip-flop having its input connected to the output of said first flip-flop for dividing the pulse repetition rate thereof by a factor of 2, a second exclusive OR gate having one input connected to said second flip-flop, and a second oscillator for generating a signal having a lower frequency than said clock pulses, means connecting said second oscillator (being connected) with a second input of said second exclusive OR gate.
Claim 7
Dependent Claim
17 words
Apparatus according to claim 5, wherein said first and second oscillators are manually adjustable variable frequency oscillators.
Claim 8
Dependent Claim
21 words
Apparatus according to claim 5, wherein the frequency of said second oscillator differs slightly from half that of said first oscillator.
Claim 9
Dependent Claim
105 words
A chorus generator for an electronic musical instrument comprising a frequency synthesizer for each octave of said instrument, a source of clock pulses directly connected to one of said frequency synthesizers, and circuit means connected to the remaining ones of said frequency synthesizers for supplying each of the remaining ones of said frequency synthesizers with a train of pulses, said trains of pulses having pulse repetition rates which are harmonically related approximately by powers of 2, and a plurality of manually adjustable oscillators connected with said circuit means for selecting the amount by whIch said pulse trains differ from being related by powers of 2.
Claim 10
Dependent Claim
105 words
A chorus generator for an electronic musical instrument comprising a frequency synthesizer for each octave of said instrument, a source of clock pulses directly connected to one of said frequency synthesizers, and circuit means connected to the remaining ones of said frequency synthesizers for supplying each of the remaining ones of said frequency synthesizers with a train of pulses, said trains of pulses having pulse repetition rates which are harmonically related approximately by powers of 2, and a plurality of manually adjustable oscillators connected with said circuit means for selecting the amount by whIch said pulse trains differ from being related by powers of 2.
Claim 11
Dependent Claim
49 words
Apparatus according to claim 1, wherein said frequency divider means includes deriving means for deriving a train of pulses having a pulse repetition rate which differs from said clock pulses by a factor of two, and means connected with said deriving means for periodically omitting pulses from said train.
Claim 12
Dependent Claim
50 words
Apparatus according to claim 1, wherein said frequency divider means includes deriving means for deriving a train of pulses having a pulse repetition rate which differs from said clock pulses by a factor of two, and means connected with said deriving means for periodically inserting additional pulses into said train.
Claim 13
Dependent Claim
14 words
Apparatus according to claim 10, wherein said last named means comprises a monostable multivibrator.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-05 | 1978-02-04 | 1978-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-05 | 1982-02-04 | 1982-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-05 | 1986-02-04 | 1986-08-06 | $7700.00 | Window Closed / Lapsed |