US4137810A
Expired / Lapsed
US
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Digitally encoded top octave frequency generator
Assignee: GIBSON PIANO VENTURES Inc A DELAWARE Corp
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Filing: 1977-01-12
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Granted: 1979-02-06
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Expires: 1997-01-12
Abstract
Abstract A LSI (large scale integrated circuit) device is disclosed which generates 12 output frequencies related to each other by a multiple of the twelfth root of two from a common time base without the use of parallel divider or shift register strings. The output frequencies comprise the top octave, or a multiple thereof, of the frequencies of an electronic musical instrument. A binary counter serves as a common time base and encodes each wave form period in a form of a binary code. A binary processing circuit associated with each output frequency stores the count position of the next desired wave form transition and updates the stored code after each transition has occurred. The binary processing circuitry comprises a latch circuit, a binary full adder or ROM (read only memory), a digital comparator or ROM, and a J-K flip-flop circuit. The outputs can be easily modified in both actual frequency and waveform symmetry.
Inventors
- 👤 Robert W. Wheelwright
- 👤 Peter E. Solender
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:58
CPC Classifications
G; G10; G10H; G10H5/00; G10H7/00; G10H7/008
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
111 words
A tone generating circuit for an electronic musical instrument comprising means for producing a predetermined frequency, a common digital counter having an input connected to said frequency producing means and having common output means, a plurality of parallel frequency branches connected to said common output means and each comprising a digital processing circuit having a digital output which is either a logical one or zero, and number source means connected to said frequency branches to alternate the digital output between one and zero at a rate determined jointly by said predetermined frequency and said number source means, thus to construct a rectangular wave output of different frequency from each frequency branch.
Claim 2
Dependent Claim
111 words
A tone generating circuit for an electronic musical instrument comprising means for producing a predetermined frequency, a common digital counter having an input connected to said frequency producing means and having common output means, a plurality of parallel frequency branches connected to said common output means and each comprising a digital processing circuit having a digital output which is either a logical one or zero, and number source means connected to said frequency branches to alternate the digital output between one and zero at a rate determined jointly by said predetermined frequency and said number source means, thus to construct a rectangular wave output of different frequency from each frequency branch.
Claim 3
Dependent Claim
21 words
A tone generating circuit as set forth in claim 1 wherein the means for producing a predetermined frequency comprises a clock.
Claim 4
Dependent Claim
19 words
A tone generating circuit as set forth in claim 1 wherein the counter comprises a nine bit binary counter.
Claim 5
Dependent Claim
17 words
A tone generating circuit as set forth in claim 1 wherein the counter comprises a synchronous counter.
Claim 6
Dependent Claim
136 words
A tone generating circuit for an electronic musical instrument comprising means for producing a predetermined frequency, a digital counter having an input connected to said frequency producing means and output means, a plurality of frequency branches connected to said output means and each comprising a digital processing circuit having a digital output which is either a logical one or zero, and number source means connected to said frequency branches to alternate the digital output between one and zero at a rate determined jointly by said predetermined frequency and said number source means, thus to construct a rectangular wave output of different frequency from each frequency branch, including a latch and an adder, said adder receiving one set of inputs from the latch and another set of inputs from a number source means connected to said adder.
Claim 7
Dependent Claim
136 words
A tone generating circuit for an electronic musical instrument comprising means for producing a predetermined frequency, a digital counter having an input connected to said frequency producing means and output means, a plurality of frequency branches connected to said output means and each comprising a digital processing circuit having a digital output which is either a logical one or zero, and number source means connected to said frequency branches to alternate the digital output between one and zero at a rate determined jointly by said predetermined frequency and said number source means, thus to construct a rectangular wave output of different frequency from each frequency branch, including a latch and an adder, said adder receiving one set of inputs from the latch and another set of inputs from a number source means connected to said adder.
Claim 8
Dependent Claim
26 words
A tone generating circuit as set forth in claim 1 wherein said number source means comprises a plurality of number sources, one for each frequency branch.
Claim 9
Dependent Claim
26 words
A tone generating circuit as set forth in claim 5 wherein said number source means comprises a plurality of number sources, one for each frequency branch.
Claim 10
Dependent Claim
27 words
A tone generating circuit as set forth in claim 5 wherein each digital processing circuit further includes a comparator connected to the adder and to said counter.
Claim 11
Dependent Claim
35 words
A tone producing circuit as set forth in claim 8 wherein each digital processing circuit further includes an output flip-flop connected to and controlled by the respective comparator and providing the output frequency wave form.
Claim 12
Dependent Claim
41 words
A tone generating circuit as set forth in claim 1 wherein said number source means comprises a plurality of different number sources respectively connected to the plurality of like frequency branches, and each number source providing a different, nominally fixed number.
Claim 13
Dependent Claim
23 words
A tone generating circuit as set forth in claim 10 and including means for changing at least some of said nominally fixed numbers.
Claim 14
Dependent Claim
19 words
A tone generating circuit as set forth in claim 10 wherein each nominally fixed number source comprises a ROM.
Claim 15
Dependent Claim
26 words
A tone generating circuit as set forth in claim 11 wherein the means for changing the nominally fixed numbers is arranged to transpose the output frequencies.
Claim 16
Dependent Claim
31 words
A tone generating circuit as set forth in claim 11 in which the means for changing the nominally fixed numbers effects a change in duty cycle of the rectangular waves constructed.
Claim 17
Dependent Claim
18 words
A tone generating circuit as set forth in claim 1 wherein the number source means comprises a ROM.
Claim 18
Dependent Claim
127 words
A tone generating circuit for an electronic musical instrument comprising a clock, a digital counter having an input connected to said clock and having output means, and a plurality of like frequency branches each comprising a digital processing circuit including a buffer connected to said counter output means, an adder connected to said buffer, a nominally fixed number source connected to said adder, a comparator connected to said adder and also to said counter output, and a flip-flop output means connected to said comparator and controlled thereby to produce either a logical one or zero output, said counter output means and said nominally fixed number source controlling conjointly the state of said output flip-flop to construct a rectangular wave output of different frequency in each frequency branch.
Claim 19
Dependent Claim
127 words
A tone generating circuit for an electronic musical instrument comprising a clock, a digital counter having an input connected to said clock and having output means, and a plurality of like frequency branches each comprising a digital processing circuit including a buffer connected to said counter output means, an adder connected to said buffer, a nominally fixed number source connected to said adder, a comparator connected to said adder and also to said counter output, and a flip-flop output means connected to said comparator and controlled thereby to produce either a logical one or zero output, said counter output means and said nominally fixed number source controlling conjointly the state of said output flip-flop to construct a rectangular wave output of different frequency in each frequency branch.
Claim 20
Dependent Claim
16 words
A tone generating circuit as set forth in claim 16 wherein said buffer comprises a latch.
Claim 21
Dependent Claim
31 words
A tone generating circuit as set forth in claim 16 wherein said number source comprises a predetermined combination of a fixed voltage and ground connected to different inputs to said adder.
Claim 22
Dependent Claim
17 words
A tone generating circuit as set forth in claim 16 wherein said number source comprises a ROM.
Claim 23
Dependent Claim
22 words
A tone generating circuit as set forth in claim 16 and further including a feedback circuit from said comparator to said buffer.
Claim 24
Dependent Claim
39 words
A tone generating circuit as set forth in claim 1 and further including multiplexing means for serially adding the output of said binary counter and said number source means at a rate other than that of said predetermined frequency.
Claim 25
Dependent Claim
84 words
A digitally encoded waveform generator comprising a clock, a free running digital counter having an input connected to said clock and having output means, a digital processing circuit connected to said output means and having a digital output which is either a logical one or zero, and a number source connected to said digital processing circuit to alternate the digital output between one and zero at a rate determined jointly by said clock and said number source, thus to construct a rectangular wave output.
Claim 26
Dependent Claim
84 words
A digitally encoded waveform generator comprising a clock, a free running digital counter having an input connected to said clock and having output means, a digital processing circuit connected to said output means and having a digital output which is either a logical one or zero, and a number source connected to said digital processing circuit to alternate the digital output between one and zero at a rate determined jointly by said clock and said number source, thus to construct a rectangular wave output.
Claim 27
Dependent Claim
33 words
A digitally encoded frequency generator as set forth in claim 22 wherein said number source comprises means for changing the number supplied thereby to said digital processing circuit, in a time variable manner.
Claim 28
Dependent Claim
25 words
A digitally encoded frequency generator as set forth in claim 23 wherein the number source comprises a ROM and control means for addressing said ROM.
Claim 29
Dependent Claim
24 words
A digitally encoded frequency generator as set forth in claim 24 wherein the counter addressing said ROM is driven by the rectangular wave output.
Claim 30
Dependent Claim
26 words
A digitally encoded frequency generator as set forth in claim 24 wherein the counter addressing said ROM is driven by a separate clock or external means.
Claim 31
Dependent Claim
41 words
A digitally encoded frequency generator as set forth in claim 22 including a plurality of like parallel digital processing circuits connected to said counter output means, and a plurality of number sources each connected to one of said digital processing circuits.
References Cited (Backward Citations)
US3939751A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-02-05 | 1982-08-07 | 1983-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-05 | 1986-08-07 | 1987-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-05 | 1990-08-07 | 1991-02-06 | $7700.00 | Window Closed / Lapsed |