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Patent US4027569A successfully refreshed from Google Patents.
US4027569A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Keyboard for an electronic musical instrument employing variable capacitors
Assignee: NORLIN MUSIC Inc
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Filing: 1975-06-19
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Granted: 1977-06-07
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Expires: 1995-06-19
Abstract
Abstract A keyboard of an electronic musical instrument incorporates a plurality of variable capacitors, one for each key, with one conductor of each capacitor being connected for movement with an individual key of the keyboard toward and away from the other conductor, so as to vary the capacitance of the capacitor in accordance with the force with which the key is depressed.
Inventors
- 👤 David A. Luce
- 👤 Anthony Marchese
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:32
CPC Classifications
G; G10; G10H; G10H1/00; G10H1/02; G10H1/04; G10H1/053; G10H1/055; G10H1/0551; Y; Y10; Y10S; Y10S84/00; Y10S84/07
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
147 words
For use with an electronic musical instrument having a keyboard for selecting sounds to be audibly produced, said keyboard having a plurality of pivotal keys, the combination comprising a variable capacitor associated with a key of said keyboard, said variable capacitor having a first conductor, and a second conductor in the form of a resilient conductive member, one of said conductors being shaped relative to the other so that relative movement of said conductors deforms said resilient member from its normal shape, and including a layer of insulation between said first and second conductors, one of said first and second conductors being fixed in position and the other being connected to said key, for movement relative to each other in response to operation of said key of said keyboard, for selectively varying the capacitance of said capacitor in accordance with the amount of movement of said key.
Claim 2
Dependent Claim
147 words
For use with an electronic musical instrument having a keyboard for selecting sounds to be audibly produced, said keyboard having a plurality of pivotal keys, the combination comprising a variable capacitor associated with a key of said keyboard, said variable capacitor having a first conductor, and a second conductor in the form of a resilient conductive member, one of said conductors being shaped relative to the other so that relative movement of said conductors deforms said resilient member from its normal shape, and including a layer of insulation between said first and second conductors, one of said first and second conductors being fixed in position and the other being connected to said key, for movement relative to each other in response to operation of said key of said keyboard, for selectively varying the capacitance of said capacitor in accordance with the amount of movement of said key.
Claim 3
Dependent Claim
36 words
Apparatus according to claim 1, wherein said first conductor is secured to said key for movement therewith, and said second conductor is mounted in fixed relation to said keyboard in spaced relation to said first conductor.
Claim 4
Dependent Claim
39 words
Apparatus according to claim 1, wherein said second conductor is formed of a sheet of conductive elastomer, a portion of said conductive elastomer conforming to the shape of a portion of said first conductor as said key is depressed.
Claim 5
Dependent Claim
21 words
Apparatus according to claim 3, including resilient means engaging said conductive elastomer for urging said second conductor toward said first conductor.
Claim 6
Dependent Claim
21 words
Apparatus according to claim 1, including a plurality of said variable capacitors juxtaposed with said keyboard, one for each key thereof.
Claim 7
Dependent Claim
28 words
Apparatus according to claim 1, wherein said first conductor is formed of a metal having an insulating oxide, said layer of insulation being formed of said insulating oxide.
Claim 8
Dependent Claim
18 words
Apparatus according to claim 6, wherein said metal is selected from the group containing aluminum, titanium, and chromium.
Claim 9
Dependent Claim
46 words
Apparatus according to claim 1, including a plurality of variable capacitors each with an individual first conductor member, and means for connecting each of said variable capacitors individually with a key of said keyboard, whereby operation of said keys varies the capacitance of their respective capacitors.
Claim 10
Dependent Claim
13 words
Apparatus according to claim 1, wherein said first conductor has a convex shape.
Claim 11
Dependent Claim
16 words
Apparatus according to claim 1, wherein said first conductor is formed of solid non-resilient conducting material.
Claim 12
Dependent Claim
19 words
Apparatus according to claim 1, wherein said first conductor is formed with a spherical surface facing said second conductor.
Claim 13
Dependent Claim
20 words
Apparatus according to claim 1, wherein said first conductor is formed with an irregular convex surface facing said second conductor.
Claim 14
Dependent Claim
31 words
Apparatus according to claim 1, including means connecting one of said conductors to said key for causing said conductors to move toward each other in response to operation of said key.
Claim 15
Dependent Claim
34 words
Apparatus according to claim 1, wherein said other conductor is rigidly connected to said key and extends downwardly of said key, with said one conductor being rigidly supported in fixed position below said key.
Claim 16
Dependent Claim
30 words
Apparatus according to claim 1, wherein said first conductor is shaped in relation to said second conductor to provide a non-linear rate of change of capacitance relative to key movement.
Claim 17
Dependent Claim
16 words
Apparatus according to claim 1, wherein said other conductor is small in relation to said key.
Claim 18
Dependent Claim
27 words
Apparatus according to claim 1, wherein said resilient member is deformable by bending simultaneously about two orthogonal axes, to partially envelop a surface of said shaped conductor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-06 | 1980-12-06 | 1981-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-06 | 1984-12-06 | 1985-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-06 | 1988-12-06 | 1989-06-07 | $7700.00 | Window Closed / Lapsed |