Patent US3740746A successfully refreshed from Google Patents.
US3740746A
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Magnetic keyboard
Assignee: Alcatel CIT SA
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Filing: 1971-11-30
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Granted: 1973-06-19
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Expires: 1991-11-30
Abstract
Abstract Magnetic keyboard transforms the depression of a key to electric signals corresponding to a numerical code, comprising circuits having superimposed coils, magnetically decoupled by a conductive disc placed in the immediate vicinity of the primary circuit. The depression of a key moves the conductive disc away and couples the secondary coil to the primary coil.
Inventors
- 👤 G Dureau
- 👤 L Roche
- 👤 M Villain
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:52
CPC Classifications
H; H04; H04L; H04L17/00; H04L17/02; H04L17/04; G; G06; G06C; G06C7/00; G06C7/02; G11; G11C; G11C17/00; G11C17/02; H03; H03K; H03K17/00; H03K17/94; H03K17/965; H03K17/97; H03K17/972
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
179 words
In a magnetic keyboard for the input in digital systems of data in the form of a code having N digits said keyboard comprising M keys and associated coding means, the improvement wherein said coding means comprise: M keyboard transformers, one per key, each consisting of a primary coil and of a secondary coil arranged face to face on an insulating support and a decoupling means; a coding matrix having N + 1 lines and M columns comprising (M X N + 1) coding transformers each consisting of a primary coil and a secondary coil arranged face to face on an insulating support; a coding layer acting upon said coding matrix; a voltage supply feeding the primary coils of the M keyboard transformers; and means connecting said primary coils of the M keyboard transformers in series and means connecting the secondary coil of each of the M keyboard transformers to the input of one of the M columns of the coding matrix consisting of the N + 1 primary coils of (N + 1) coding transformers connected in series.
Claim 2
Dependent Claim
179 words
In a magnetic keyboard for the input in digital systems of data in the form of a code having N digits said keyboard comprising M keys and associated coding means, the improvement wherein said coding means comprise: M keyboard transformers, one per key, each consisting of a primary coil and of a secondary coil arranged face to face on an insulating support and a decoupling means; a coding matrix having N + 1 lines and M columns comprising (M X N + 1) coding transformers each consisting of a primary coil and a secondary coil arranged face to face on an insulating support; a coding layer acting upon said coding matrix; a voltage supply feeding the primary coils of the M keyboard transformers; and means connecting said primary coils of the M keyboard transformers in series and means connecting the secondary coil of each of the M keyboard transformers to the input of one of the M columns of the coding matrix consisting of the N + 1 primary coils of (N + 1) coding transformers connected in series.
Claim 3
Dependent Claim
33 words
The magnetic keyboard according to claim 1, wherein the decoupling means consists of a conductive disc spring biased against the primary coil but electrically insulated from the latter by a thin insulating film.
Claim 4
Dependent Claim
51 words
The magnetic keyboard according to claim 1, wherein the coding layer acting upon the coding matrix consists of an insulating film applied on the said coding matrix and bearing, opposite each coding transformer to be decoupled, a disc made of conductive material having substantially the same diameter as the primary coil.
Claim 5
Dependent Claim
51 words
The magnetic keyboard according to claim 2, wherein the coding layer acting upon the coding matrix consists of an insulating film applied on the said coding matrix and bearing, opposite each coding transformer to be decoupled, a disc made of conductive material having substantially the same diameter as the primary coil.
Claim 6
Dependent Claim
41 words
The magnetic keyboard according to claim 1, further comprising a dummy compensation keyboard identical, from the electrical point of view, with the magnetic active keyboard, in which each keyboard transformer is provided with a conductive disc simulating a key at rest.
Claim 7
Dependent Claim
41 words
The magnetic keyboard according to claim 2, furtHer comprising a dummy compensation keyboard identical, from the electrical point of view, with the magnetic active keyboard, in which each keyboard transformer is provided with a conductive disc simulating a key at rest.
Claim 8
Dependent Claim
41 words
The mangetic keyboard according to claim 3, further comprising a dummy compensation keyboard identical, from the electrical point of view, with the magnetic active keyboard, in which each keyboard transformer is provided with a conductive disc simulating a key at rest.
Claim 9
Dependent Claim
37 words
The magnetic keyboard according to claim 1, wherein each secondary turn of each keyboard transformer, the N + 1 series connected primary coils of the coding matrix corresponding thereto form a single circuit on an insulating film.
Claim 10
Dependent Claim
37 words
The magnetic keyboard according to claim 2, wherein each secondary turn of each keyboard transformer, the N + 1 series connected primary coils of the coding matrix corresponding thereto form a single circuit on an insulating film.
Claim 11
Dependent Claim
37 words
The magnetic keyboard according to claim 3, wherein each secondary turn of each keyboard transformer, the N + 1 series connected primary coils of the coding matrix corresponding thereto form a single circuit on an insulating film.
Claim 12
Dependent Claim
54 words
The magnetic keyboard according to claim 5, wherein each secondary turn of each keyboard transformer, the N + 1 series connected primary coils of the coding matrix corresponding thereto and the secondary coil which is the element corresponding to the dummy keyboard, if there exists one, form a single circuit on an insulating film.
Claim 13
Dependent Claim
20 words
The magnetic keyboard according to claim 8, wherein each of the said circuits is deposited on the same insulating film.
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) | 1976-06-18 | 1976-12-18 | 1977-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-18 | 1980-12-18 | 1981-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-18 | 1984-12-18 | 1985-06-19 | $7700.00 | Window Closed / Lapsed |