US3631472A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Capacitive keying module and system
Assignee: Unisys Corp
•
Filing: 1970-01-02
•
Granted: 1971-12-28
•
Expires: 1990-01-02
Abstract
Abstract A modular key for an electrical keyboard employs a capacitive voltage divider circuit with stator and armature capacitive elements forming a pair of capacitors in ganged relation. Downward motion of one capacitor element when a key is manually depressed produces a corresponding change in the output of the divider sufficient to overcome the threshold of a transistor detector circuit. An inverted output data pulse is supplied, free of disturbing transients, at the input of associated digital processing equipment.
Inventors
- 👤 Andrew J Lincoln
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:28
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/94; H03K17/965; H03K17/975; H03K17/98; G; G06; G06C; G06C7/00; G06C7/02
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
128 words
In a manually operable modular keying means: first means having a first capacitive surface, second means having at least second and third spaced capacitive surfaces cooperative with said first capacitive surface, said second capacitive surface being adapted for coupling to pulsE train signal generator means, said third capacitive surface being adapted for coupling to pulse signal utilization means, manually operable means providing relative motion between said first and second means from a first positional relation to a second positional relation whereby said capacitive surface of said first means capacitively couples said second and third spaced capacitive surfaces in said first positional relation and provides substantially no such capacitive coupling in said second positional relation, and means for returning said first and second means to said first positional relation.
Claim 2
Dependent Claim
128 words
In a manually operable modular keying means: first means having a first capacitive surface, second means having at least second and third spaced capacitive surfaces cooperative with said first capacitive surface, said second capacitive surface being adapted for coupling to pulsE train signal generator means, said third capacitive surface being adapted for coupling to pulse signal utilization means, manually operable means providing relative motion between said first and second means from a first positional relation to a second positional relation whereby said capacitive surface of said first means capacitively couples said second and third spaced capacitive surfaces in said first positional relation and provides substantially no such capacitive coupling in said second positional relation, and means for returning said first and second means to said first positional relation.
Claim 3
Dependent Claim
31 words
Apparatus as described in claim 1 wherein said second means is provided with at least one insulator surface with second, third and fourth spaced capacitive surfaces affixed to said insulator surface.
Claim 4
Dependent Claim
43 words
Apparatus as described in claim 2 wherein said capacitive surface of said first means capacitively couples said second and third spaced capacitive surfaces in said first positional relation and capacitively couples said third and fourth spaced capacitive surfaces in said second positional relation.
Claim 5
Dependent Claim
16 words
Apparatus as described in claim 1 wherein said first means consists of an electrically conductive metal.
Claim 6
Dependent Claim
13 words
Apparatus as described in claim 1 wherein said first means is substantially cruciform.
Claim 7
Dependent Claim
31 words
Apparatus as described in claim 1 wherein said first means is formed of a dielectric material with at least one surface of said material being provided with an electrically capacitive surface.
Claim 8
Dependent Claim
24 words
Apparatus as described in claim 1 wherein said capacitive surface of said first means is electrically insulated so that its electrical potential is self-adjusting.
Claim 9
Dependent Claim
18 words
Apparatus as described in claim 1 wherein said second means has a surface composed of an electrical insulator.
Claim 10
Dependent Claim
36 words
Apparatus as described in claim 2 wherein said second, third, and fourth spaced capacitive surfaces are provided with first, second, and third electrical terminals providing means for connection to circuit means external of said second means.
Claim 11
Dependent Claim
44 words
Apparatus as described in claim 9 wherein said first terminal is connected to ground, said second terminal is connected to supply voltage of level VOUT to utilization apparatus, and said third terminal is connected to a generator of electrical pulses of voltage level VIN.
Claim 12
Dependent Claim
32 words
Apparatus as described in claim 2 wherein a thin film of solid dielectric material lies between said capacitive surface of said first means and said second, third, and fourth spaced capacitive surfaces.
Claim 13
Dependent Claim
27 words
Apparatus as described in claim 10 wherein voltage level VOUT is increased when said first means and said second means are changed to said first positional relation.
Claim 14
Dependent Claim
37 words
Apparatus as described in claim 10 wherein said utilization apparatus includes an amplifier with a threshold potential lying between values of VOUT characteristic of said respective first and second positional relations of said first and second means.
Claim 15
Dependent Claim
34 words
Apparatus as described in claim 13 wherein the input supplying voltage VOUT to said amplifier includes a path from said input to ground for undesired transient signals for the purpose of protecting said amplifier.
Claim 16
Dependent Claim
40 words
Apparatus as described in claim 1 wherein said second means includes at least one external surface having depressions adapted to cooperate with keyboard mounted spring means for holding said modular keying means within an array of said modular keying means.
References Cited (Backward Citations)
US3257658A
Cited
US3293640A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-27 | 1975-06-28 | 1975-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-27 | 1979-06-28 | 1979-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-27 | 1983-06-28 | 1983-12-28 | $7700.00 | Window Closed / Lapsed |