US3876936A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Visual audio frequency comparator
Assignee: Motorola Solutions Inc
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Filing: 1973-09-17
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Granted: 1975-04-08
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Expires: 1993-09-17
Abstract
Abstract A system for determining the frequency relationship between two notes of a musical instrument includes a split screen display device, and bar generating means connected to the instrument and display device for generating a first plurality of bars representative of the frequency of the first note on one portion of the display device and a second plurality of bars representative of the frequency of the second note on another portion of the display device. The vertical sweep circuit of the display device is synchronized to the frequency of one of the notes.
Inventors
- 👤 Theodore V Lester
- 👤 Donald C Ryon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:36
CPC Classifications
G; G01; G01R; G01R23/00; G01R13/00; G01R13/20; G01R13/22; G01R13/28; G10; G10H; G10H1/00; G10H1/44
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
223 words
A system for comparing the frequencies of first and second musical notes including in combination: means for receiving a first alternating current signal having a predetermined frequency relationship to the frequency of said first musical note; means for receiving a second alternating current signal having a predetermined frequency relationship to the frequency of said second musical note; display means for visually displaying bars in response to alternating current signals applied thereto, the number and position of the bars displayed being proportional to the frequency and phase, respectively, of the alternating current signals applied to said display means said display means including a display device, and a high frequency sweep circuit and a low frequency sweep circuit coupled to said display device, one of said sweep circuits being horizontal and the other being vertical for generating a raster on said display device; and gating means connected to said first and second alternating current signal receiving means and to said display means for alternately applying signals, representative of one of said first and second alternating current signals, to said display means an output of said high frequency sweep circuit being connected to said gating means for causing said gating means to alternately apply one of said first and second alternating current representative signals to said display means for a portion of each high frequency sweep.
Claim 2
Independent Claim
223 words
A system for comparing the frequencies of first and second musical notes including in combination: means for receiving a first alternating current signal having a predetermined frequency relationship to the frequency of said first musical note; means for receiving a second alternating current signal having a predetermined frequency relationship to the frequency of said second musical note; display means for visually displaying bars in response to alternating current signals applied thereto, the number and position of the bars displayed being proportional to the frequency and phase, respectively, of the alternating current signals applied to said display means said display means including a display device, and a high frequency sweep circuit and a low frequency sweep circuit coupled to said display device, one of said sweep circuits being horizontal and the other being vertical for generating a raster on said display device; and gating means connected to said first and second alternating current signal receiving means and to said display means for alternately applying signals, representative of one of said first and second alternating current signals, to said display means an output of said high frequency sweep circuit being connected to said gating means for causing said gating means to alternately apply one of said first and second alternating current representative signals to said display means for a portion of each high frequency sweep.
Claim 3
Dependent Claim
56 words
A system as recited in claim 1 wherein said low frequency sweep circuit is connected to said first signal receiving means, said low frequency sweep circuit being responsive to said first signal receiving means for synchronizing the frequency of operation of said low frequency sweep circuit o a submultiple of the frequency of said first signal.
Claim 4
Dependent Claim
40 words
A system as recited in claim 2 wherein said first and second signal receiving means include a limiting amplifier for generating signals having a substantially rectangular wave shape in response to said first and second alternating current signals applied thereto.
Claim 5
Dependent Claim
50 words
A system as recited in claim 3 further including means for modulating the raster generated by said horizontal and vertical sweep circuits, said modulating means being connected to said gating means and to said display device for modulating the raster in response to said first and second alternating current signals.
References Cited (Backward Citations)
US3074054A
Cited
US3287639A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |