US3617600A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic field responsive key switch device for producing attack effect in electronic musical instruments
Assignee: Nippon Gakki Co Ltd
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Filing: 1969-03-24
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Granted: 1971-11-02
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Expires: 1989-03-24
Abstract
Abstract A key device for electronic musical instruments. A key in the keyboard has a magnet attached thereto directly or by way of a spring plate, and a magnetoresistor, which is an element the electric conductivity of which is controlled by the magnetic field of the magnet, is positioned at the place where the magnetic field of said magnet is applied when the key is depressed or beaten. The magnetoresistor is connected in the switching circuit of the instrument as a switch element so as to produce more voluminous sounds as said magnet comes near to said element. An elastic material such as sponge rubber of felt is mounted on the instrument beneath the key to define the lower position of the key. The combination of the spring plate attached to the key and the stop material to limit the lower position of the key makes possible an attack effect and touch-sensitive control effect during use of the keys.
Inventors
- 👤 Junji Ohno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 00:25
CPC Classifications
G; G10; G10H; G10H1/00; G10H1/02; G10H1/04; G10H1/053; G10H1/055; G10H1/0555; Y; Y10; Y10S; Y10S84/00; Y10S84/07
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
208 words
A key switch device for an electronic musical instrument comprising a key movably supported in the instrument so as to be depressed when it is moved, a spring plate having one end attached to the underside of said key and having the other end free, a magnet element mounted on the free end of said spring plate, and magnetoresistor element the electrical resistance of which varies in accordance with the intensity of magnetic field applied thereto and adapted to be connected in the tonegeneration system of the instrument, said magnetoresistor element being fixed position under said key at a predetermined distance from said magnet element when said key is in the underpressed condition, the said distance being slightly greater than the distance the key moves when it is depressed, whereby when the key is depressed gently the magnet element approaches the stops near the magnetoresistor element relatively slowly, and when the key is depressed forcibly the magnet element approaches the magnetoresistor element rapidly and at the end of the depressing movement the inertia of the magnet element causes it to approach closer to the magnetoresistor element than when the key is depressed gently and then to spring back the invention will be described close approach position. 5, 6,
Claim 2
Dependent Claim
208 words
A key switch device for an electronic musical instrument comprising a key movably supported in the instrument so as to be depressed when it is moved, a spring plate having one end attached to the underside of said key and having the other end free, a magnet element mounted on the free end of said spring plate, and magnetoresistor element the electrical resistance of which varies in accordance with the intensity of magnetic field applied thereto and adapted to be connected in the tonegeneration system of the instrument, said magnetoresistor element being fixed position under said key at a predetermined distance from said magnet element when said key is in the underpressed condition, the said distance being slightly greater than the distance the key moves when it is depressed, whereby when the key is depressed gently the magnet element approaches the stops near the magnetoresistor element relatively slowly, and when the key is depressed forcibly the magnet element approaches the magnetoresistor element rapidly and at the end of the depressing movement the inertia of the magnet element causes it to approach closer to the magnetoresistor element than when the key is depressed gently and then to spring back the invention will be described close approach position. 5, 6,
Claim 3
Dependent Claim
33 words
A key switch device as claimed in claim 1 of a further comprises a stop of elastic material disposed under said key for determining the lower limit to the movement of said key.
Claim 4
Dependent Claim
204 words
A key switch device for an electronic musical instrument comprising a key movably supported in the instrument so as to be depressed when it is moved, a spring plate having one end attached to the underside of said key and having the other end free, a magnetoresistor element the electrical resistance of which varies in accordance with the intensity of magnetic field applied thereto and adapted to be connected in the tone-generation system of the instrument, said magnetoresistor element being mounted on the free end of said spring plate, a magnet element fixed in position under said key at a predetermined distance from said magnetoresistor element when said key is in the undepressed condition, the said distance being slightly greater than the distance the key moves when it is depressed, whereby when the key is depressed gently the magnetoresistor element approaches and stops near the magnet element relatively slowly, and when the key is depressed forcibly the magnetoresistor element approaches the magnet element rapidly and at the end of the depressing movement the inertia of the magnetoresistor element causes it to approach closer to the magnet element than when the key is depressed gently and then to spring back from said close approach position.
Claim 5
Dependent Claim
204 words
A key switch device for an electronic musical instrument comprising a key movably supported in the instrument so as to be depressed when it is moved, a spring plate having one end attached to the underside of said key and having the other end free, a magnetoresistor element the electrical resistance of which varies in accordance with the intensity of magnetic field applied thereto and adapted to be connected in the tone-generation system of the instrument, said magnetoresistor element being mounted on the free end of said spring plate, a magnet element fixed in position under said key at a predetermined distance from said magnetoresistor element when said key is in the undepressed condition, the said distance being slightly greater than the distance the key moves when it is depressed, whereby when the key is depressed gently the magnetoresistor element approaches and stops near the magnet element relatively slowly, and when the key is depressed forcibly the magnetoresistor element approaches the magnet element rapidly and at the end of the depressing movement the inertia of the magnetoresistor element causes it to approach closer to the magnet element than when the key is depressed gently and then to spring back from said close approach position.
Claim 6
Dependent Claim
32 words
A key switch device as claimed in claim 3 which further comprises a stop of elastic material disposed under said key for determining the lower limit to the movement of said key.
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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) | 1974-11-01 | 1975-05-03 | 1975-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-01 | 1979-05-03 | 1979-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-01 | 1983-05-03 | 1983-11-02 | $7700.00 | Window Closed / Lapsed |