US3668417A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Touch-sensitive switch employing electret foil
Assignee: AT&T Inc
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Filing: 1970-12-28
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Granted: 1972-06-06
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Expires: 1990-12-28
Abstract
Abstract A keyboard switching arrangement that is mechanically simple, reliable, and which can be fabricated with an overall thickness of less than 1/4 inch, includes a plurality of independent conductive elements aligned with holes in a protective front cover. A single sheet of a metallized foil electret is interposed between the cover and the conductive members. The metal layer of the foil forms a capacitive transducer with each backplate section. Each switch is operated by touching the foil electret through one of the cover holes. The resulting displacement generates an electric output signal which is utilized for actuating an associated switching element or the like.
Inventors
- 👤 Gerhard Martin Sessler
- 👤 Robert Lee Wallace Jr
- 👤 James Edward West
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:54
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/02; H04M1/23; H01; H01G; H01G7/00; H01G7/02; H01G7/021; H01G7/023; H01G7/025; H03; H03K; H03K17/00; H03K17/94; H03K17/965; H03K17/975; H03K17/98
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
136 words
A touch-sensitive signalling device, which comprises, a conductive member and spaced apart metallized electret means supported together in spaced juxtaposition in a transducer-like configuration for generating a voltage pulse in response to a tactile displacement of said electret means with relation to said conductive member, the thickness of said electret means and the spacing between said conductive member and said electret means being respectively proportioned to render said configuration insensitive to nontactile displacement forces, means for directing an externally applied tactile force to said configuration for displacing said electret means with relation to said conductive member, and means in circuit relation with said conductive member and said electret means for delivering to an external circuit the voltage developed between said conductive member and said electret means in response to a tactile displacement of said electret means.
Claim 2
Dependent Claim
136 words
A touch-sensitive signalling device, which comprises, a conductive member and spaced apart metallized electret means supported together in spaced juxtaposition in a transducer-like configuration for generating a voltage pulse in response to a tactile displacement of said electret means with relation to said conductive member, the thickness of said electret means and the spacing between said conductive member and said electret means being respectively proportioned to render said configuration insensitive to nontactile displacement forces, means for directing an externally applied tactile force to said configuration for displacing said electret means with relation to said conductive member, and means in circuit relation with said conductive member and said electret means for delivering to an external circuit the voltage developed between said conductive member and said electret means in response to a tactile displacement of said electret means.
Claim 3
Dependent Claim
29 words
A touch-sensitive signalling device as defined in claim 1, wherein, said metallized electret means comprises a plurality of thin film electrets, each with a conductive coating on one surface.
Claim 4
Dependent Claim
51 words
A touch-sensitive signalling device as defined in claim 1, wherein, said metallized electret means comprises at least one thin film electret with a conductive coating on one surface thereof, and an uncharged auxiliary film overlaying said film electret to sandwich said film electret between said auxiliary film and said conductive member.
Claim 5
Dependent Claim
99 words
A touch-sensitive signalling device, which comprises, an array of independent conductive members, metallized electret means supported in spaced juxtaposition to said conductive members, means for restricting the application of an externally applied displacement force to said electret means to locations in substantial alignment with each of said conductive members, and means in circuit relation with each of said conductive members and said electret means for delivering to an external circuit the voltage developed between a selected conductive member and said metallized electret means in response to a mechanical displacement of said electret in the location of said selected member.
Claim 6
Dependent Claim
99 words
A touch-sensitive signalling device, which comprises, an array of independent conductive members, metallized electret means supported in spaced juxtaposition to said conductive members, means for restricting the application of an externally applied displacement force to said electret means to locations in substantial alignment with each of said conductive members, and means in circuit relation with each of said conductive members and said electret means for delivering to an external circuit the voltage developed between a selected conductive member and said metallized electret means in response to a mechanical displacement of said electret in the location of said selected member.
Claim 7
Dependent Claim
27 words
A touch-sensitive signalling device as defined in claim 4, wherein, said metallized electret means comprises a thin film electret with a conductive coating on one surface thereof.
Claim 8
Dependent Claim
51 words
A touch-sensitive signalling device as defined in claim 4, wherein, said metallized electret means comprises a plurality of thin film electrets, each with a conductive coating on one surface, and means for supporting said film electrets apart from one another by a distance commensurate with the parameters of said film electrets.
Claim 9
Dependent Claim
27 words
A touch-sensitive signalling device as defined in claim 4, wherein, said metallized electret means comprises at least one foil electret and an overlaying uncharged pliable protective layer.
Claim 10
Dependent Claim
46 words
A touch-sensitive signalling device as defined in claim 4, wherein, said means for restricting the application of an externally applied displacement force to said electret means comprises, an apertured cover member overlaying said electret means with said apertures in substantial alignment, respectively, with said conductive members.
Claim 11
Dependent Claim
40 words
A touch-sensitive signalling device as defined in claim 4, wherein, said means for restricting the application of an externally applied displacement force to said electret means comprises, a plurality of individual pushbuttons in substantial alignment, respectively, with said conductive members.
Claim 12
Dependent Claim
97 words
A touch-sensitive selector which comprises, in combination, an array of conductive members, a single sheet foil electret, comprising a thin film electret metallized with a conductive coating on one surface thereof, supported in spaced juxtaposition to said members with said conductive coating away from said members, an insulating apertured cover member overlaying said foil electret with said apertures in substantial alignment with said conductive members, and means responsive to the voltage developed between a conductive member and said conductive coating on said electret occasioned by the displacement of that foil electret portion in juxtaposition to said member.
Claim 13
Dependent Claim
97 words
A touch-sensitive selector which comprises, in combination, an array of conductive members, a single sheet foil electret, comprising a thin film electret metallized with a conductive coating on one surface thereof, supported in spaced juxtaposition to said members with said conductive coating away from said members, an insulating apertured cover member overlaying said foil electret with said apertures in substantial alignment with said conductive members, and means responsive to the voltage developed between a conductive member and said conductive coating on said electret occasioned by the displacement of that foil electret portion in juxtaposition to said member.
Claim 14
Dependent Claim
58 words
A touch-sensitive selector as defined in claim 10, wherein, said array of conductive members comprises, an insulating support with recesses at selected locations therein, a plane conductive element embedded in each of said recesses at a slight distance beneath the front surface of said support, and means for connecting said conductive elements independently to said voltage responsive means.
Claim 15
Dependent Claim
26 words
A touch-sensitive selector as defined in claim 10, wherein said foil electret is polarized with different polarities at discrete areas substantially aligned with said conductive elements.
Claim 16
Dependent Claim
103 words
An electro-mechanical transducer which comprisEs, an array of independent conductive elements, a plurality of thin pliable films, at least one of which comprises a foil electret with a conductive element on one surface thereof, supported in spaced juxtaposition to said independent conductive elements with said conductive elements of all said electrets facing away from said independent elements, an apertured cover member overlaying said thin films with said apertures in substantial alignment with conductive elements of said array, and means responsive to a voltage change between selected conductive elements occasioned by the displacement of that foil electret portion in juxtaposition to said array element.
Claim 17
Dependent Claim
103 words
An electro-mechanical transducer which comprisEs, an array of independent conductive elements, a plurality of thin pliable films, at least one of which comprises a foil electret with a conductive element on one surface thereof, supported in spaced juxtaposition to said independent conductive elements with said conductive elements of all said electrets facing away from said independent elements, an apertured cover member overlaying said thin films with said apertures in substantial alignment with conductive elements of said array, and means responsive to a voltage change between selected conductive elements occasioned by the displacement of that foil electret portion in juxtaposition to said array element.
Claim 18
Dependent Claim
70 words
An electro-mechanical transducer as defined in claim 13, wherein, at least two of said thin pliable films are foil electrets held slightly apart from one another, each with their conductive elements facing away from the conductive elements of said array, and wherein said means responsive to a voltage change includes means for delivering voltage changes occasioned by the individual displacement of each of said foil electrets to an external circuit.
Claim 19
Dependent Claim
33 words
An electro-mechanical transducer as defined in claim 14, wherein, said means responsive to a voltage change includes means for altering the time of delivery of said individual voltage changes to said external circuit.
Claim 20
Dependent Claim
31 words
An electro-mechanical transducer as defined in claim 14, wherein, each of said foil electrets is polarized with selectively different polarities at discrete areas substantially in the vicinity of said conductive elements.
Claim 21
Dependent Claim
109 words
An electro-mechanical transducer as defined in claim 13, wherein, at least two of said thin pliable films are foil electrets held slightly apart from one another, each with their conductive coating facing away from the conductive elements of said array, and wherein said voltage responsive means associated with each of said independent conductive elements includes, means for delaying the voltage change on selected ones of said independent conductive elements in response to the displacement of selected foil electrets, and means for combining said delayed voltage changes from selected ones of said elements with the voltage changes from all remaining conductive elements of said array to produce a composite signal.
Claim 22
Dependent Claim
30 words
An electro-mechanical transducer as defined in claim 13, wherein, said conductive element on said surface of said foil electret is restricted to areas substantially aligned with said independent conductive elements.
Claim 23
Dependent Claim
80 words
A touch-sensitive signalling device, which comprises, a plurality of electret films, each with a conductive coating on one surface, and each supported in spaced juxtaposition to one another, means for restricting the application of an externally applied displacement force to said electret films, and means in circuit relation with said conductive coatings on said electret films for delivering to an external circuit the voltage developed therebetween in response to a mechanical displacement of at least one of said electret films.
Claim 24
Dependent Claim
80 words
A touch-sensitive signalling device, which comprises, a plurality of electret films, each with a conductive coating on one surface, and each supported in spaced juxtaposition to one another, means for restricting the application of an externally applied displacement force to said electret films, and means in circuit relation with said conductive coatings on said electret films for delivering to an external circuit the voltage developed therebetween in response to a mechanical displacement of at least one of said electret films.
Claim 25
Dependent Claim
19 words
A touch-sensitive signalling device as defined in claim 19 wherein all of said electret films are of like polarity.
Claim 26
Dependent Claim
29 words
A touch-sensitive signalling device as defined in claim 19, wherein, selected ones of said electret films are of one polarity and the remaining ones are of the opposite polarity.
Claim 27
Dependent Claim
23 words
A touch-sensitive signalling device as defined in claim 19, wherein, said electret films are polarized with selected polarities at different lateral locations therein.
Claim 28
Dependent Claim
36 words
A touch-sensitive signalling device as defined in claim 19, wherein, said means for delivering said developed voltage changes to an external circuit includes, means for altering the time of delivery of said individually developed voltage changes.
Claim 29
Dependent Claim
84 words
In a touch-sensitive signalling device in which a biased conductive diaphragm is supported in spaced juxtaposition to a conductive membeR and in which a voltage is developed between said biased conductive diaphragm and said conductive member in response to a mechanical displacement of said diaphragm, that improvement in which, said conductive diaphragm comprises at least one metallized electret film, and in which an externally applied mechanical action is directed to a predetermined location for displacing said electret film with relation to said conductive member.
Claim 30
Dependent Claim
84 words
In a touch-sensitive signalling device in which a biased conductive diaphragm is supported in spaced juxtaposition to a conductive membeR and in which a voltage is developed between said biased conductive diaphragm and said conductive member in response to a mechanical displacement of said diaphragm, that improvement in which, said conductive diaphragm comprises at least one metallized electret film, and in which an externally applied mechanical action is directed to a predetermined location for displacing said electret film with relation to said conductive member.
Claim 31
Dependent Claim
65 words
A multiple element electrostatic transducer which comprises, in combination, a planar array of mutually insulated conductive elements, a foil-electret diaphragm commensurate in area with and held in close proximity to said array of conductive elements, and means for recovering electric signals individually from said conductive elements in response to a displacement of said foil-electret portion juxtaposed respectively to said individual ones of said conductive elements.
Claim 32
Dependent Claim
65 words
A multiple element electrostatic transducer which comprises, in combination, a planar array of mutually insulated conductive elements, a foil-electret diaphragm commensurate in area with and held in close proximity to said array of conductive elements, and means for recovering electric signals individually from said conductive elements in response to a displacement of said foil-electret portion juxtaposed respectively to said individual ones of said conductive elements.
Claim 33
Dependent Claim
38 words
A touch-sensitive signalling device as defined in claim 1, wherein, said means for directing an externally applied tactile force to said configuration comprises mechanical actuator means as an interface between an applied tactile force and said electret means.
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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) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |