US4103252A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Capacitive touch-activated transducer system including a plurality of oscillators
Assignee: Xerox Corp
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Filing: 1976-11-26
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Granted: 1978-07-25
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Expires: 1996-11-26
Abstract
Abstract A human touch on an etched copper electrode produces a capacitive change to vary the time constant of an RC network as a part of an oscillator. The variation in the capacitance of the sensor changes the time constant of the RC network which results in a change in frequency of the output signal of the oscillator. This change in frequency thus varies with the human touch to the copper electrode. To develop a directional indication of the touch position, four electrodes are arranged in opposed pairs along orthogonal axes. Each electrode is part of an RC network connected to an oscillator with each of the four oscillators identified with one of the four positions along the orthogonal axes. The output signal from each of the oscillators is transmitted to timing and control circuitry that generates four separate pulse trains, one pulse train identified with each of four positions along the orthogonal axis.
Inventors
- 👤 Thomas W. Bobick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 00:43
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/94; H03K17/96; H03K17/962; G; G06; G06F; G06F3/00; G06F3/01; G06F3/03; G06F3/033; G06F3/0354; G06F3/03547
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
72 words
A capacitive activated transducer, comprising: a sensor responsive to a touch by a human operator to generate a change in capacitance, an oscillator connected to said sensor and generating a signal at a frequency varying with the capacitance of said sensor, and means for gating a pulse train signal to an output terminal, said means connected to said oscillator and responsive to a time window varying with the frequency of said oscillator.
Claim 2
Dependent Claim
72 words
A capacitive activated transducer, comprising: a sensor responsive to a touch by a human operator to generate a change in capacitance, an oscillator connected to said sensor and generating a signal at a frequency varying with the capacitance of said sensor, and means for gating a pulse train signal to an output terminal, said means connected to said oscillator and responsive to a time window varying with the frequency of said oscillator.
Claim 3
Dependent Claim
31 words
A capacitive activated transducer as set forth in claim 1 wherein said oscillator includes an integrated circuit generating pulse signals at a repetition rate related to the capacitance of said sensor.
Claim 4
Dependent Claim
27 words
A capacitive activated transducer as set forth in claim 2 wherein said gating means is responsive to the output of said integrated circuit and to enabling pulses.
Claim 5
Dependent Claim
42 words
A capacitive activated transducer as set forth in claim 1 wherein said sensor includes a substrate of an electrically insulating material with an etched copper pattern overlaying said substrate connected to said oscillator and responsive to a touch by a human operator.
Claim 6
Dependent Claim
99 words
A capacitive activated transducer, comprising: a sensor having a plurality of electrodes, each responsive to a touch by a human operator to generate a change in capacitance at each electrode, and a plurality of oscillators equal in number to said plurality of electrodes, each oscillator connected to one of said electrodes and generating a signal at a frequency related to the capacitance of said electrode, and timing and control means connected to said plurality of oscillators for gating a pulse train signal to an output terminal for a preset time window varying with the frequency signal from said oscillators.
Claim 7
Dependent Claim
99 words
A capacitive activated transducer, comprising: a sensor having a plurality of electrodes, each responsive to a touch by a human operator to generate a change in capacitance at each electrode, and a plurality of oscillators equal in number to said plurality of electrodes, each oscillator connected to one of said electrodes and generating a signal at a frequency related to the capacitance of said electrode, and timing and control means connected to said plurality of oscillators for gating a pulse train signal to an output terminal for a preset time window varying with the frequency signal from said oscillators.
Claim 8
Dependent Claim
36 words
A capacitive activated transducer as set forth in claim 5 wherein each of said oscillators includes an integrated logic circuit generating pulse signals at a repetition rate related to the capacitance of the electrode connected thereto.
Claim 9
Dependent Claim
24 words
A capacitive activated transducer as set forth in claim 5 wherein said sensor consists of two pairs of opposed electrodes oriented along orthogonal axes.
Claim 10
Dependent Claim
28 words
A capacitive activated transducer as set forth in claim 7 including a finger electrode extending inward from each of said electrodes toward the intersection of the orthogonal axes.
Claim 11
Dependent Claim
32 words
A capacitive activated transducer as set forth in claim 5 wherein said sensor includes a substrate of an electrically insulating material with the electrodes consisting of a copper pattern on said substrate.
Claim 12
Dependent Claim
18 words
A capacitive activated transducer as set forth in claim 9 including a protective shield overlaying said copper electrodes.
Claim 13
Dependent Claim
156 words
A sensor for a capacitive activated transducer, comprising: a first pair of opposed electrodes positioned along a first of two orthogonal axes and spaced an equal and predetermined distance from the intersection of said orthogonal axes, each electrode of said first pair having a shape symmetrical with said first orthogonal axis, and a second pair of opposed electrodes positioned along the second of said two orthogonal axes and spaced an equal and predetermined distance from the intersection of said orthogonal axes, each electrode of said second pair having a shape symmetrical with said second orthogonal axis and positioned with respect to the adjacent electrodes of said first pair such that a predetermined portion of the periphery of said electrode is spaced a predetermined distance from a corresponding portion of said adjacent electrodes, whereby a change in capacitance may be sensed with respect to the two orthogonal axes when the sensor is touched by a human operator.
Claim 14
Dependent Claim
156 words
A sensor for a capacitive activated transducer, comprising: a first pair of opposed electrodes positioned along a first of two orthogonal axes and spaced an equal and predetermined distance from the intersection of said orthogonal axes, each electrode of said first pair having a shape symmetrical with said first orthogonal axis, and a second pair of opposed electrodes positioned along the second of said two orthogonal axes and spaced an equal and predetermined distance from the intersection of said orthogonal axes, each electrode of said second pair having a shape symmetrical with said second orthogonal axis and positioned with respect to the adjacent electrodes of said first pair such that a predetermined portion of the periphery of said electrode is spaced a predetermined distance from a corresponding portion of said adjacent electrodes, whereby a change in capacitance may be sensed with respect to the two orthogonal axes when the sensor is touched by a human operator.
Claim 15
Dependent Claim
31 words
A sensor for a capacitive activated transducer as set forth in claim 11 wherein said first and second pairs of electrodes have a shape whose outer peripheries form a ring-shaped configuration.
Claim 16
Dependent Claim
27 words
A sensor for a capacitive activated transducer as set forth in claim 12 wherein the radius of the outer edge of the ring-shaped configuration is substantially constant.
Claim 17
Dependent Claim
30 words
A sensor for a capacitive activated transducer as set forth in claim 11 including a finger electrode extending toward the intersection of said orthogonal axes from each of said electrodes.
Claim 18
Dependent Claim
26 words
A sensor for a capacitive activated transducer as set forth in claim 14 wherein each finger electrode is oriented along one of the two orthogonal axes.
Claim 19
Dependent Claim
169 words
A sensor for a capacitive activated transducer, comprising: a substrate of an electrically insulating material, a first pair of opposed electrodes formed on said substrate along a first of two orthogonal axes and spaced an equal and predetermined distance from the intersection of said orthogonal axes, each electrode of said first pair having a shape symmetrical with said first orthogonal axis, and a second pair of opposed electrodes formed on said substrate along the second of said two orthogonal axes and spaced an equal and predetermined distance from the intersection of said orthogonal axes, each electrode of said second pair having a shape symmetrical with said second orthogonal axis and positioned with respect to the adjacent electrodes of said first pair such that a predetermined portion of the periphery of said electrode is spaced a predetermined distance from a corresponding portion of said adjacent electrodes, whereby a change in capacitance may be sensed with respect to the two orthogonal axes when the sensor is touched by a human operator.
Claim 20
Dependent Claim
169 words
A sensor for a capacitive activated transducer, comprising: a substrate of an electrically insulating material, a first pair of opposed electrodes formed on said substrate along a first of two orthogonal axes and spaced an equal and predetermined distance from the intersection of said orthogonal axes, each electrode of said first pair having a shape symmetrical with said first orthogonal axis, and a second pair of opposed electrodes formed on said substrate along the second of said two orthogonal axes and spaced an equal and predetermined distance from the intersection of said orthogonal axes, each electrode of said second pair having a shape symmetrical with said second orthogonal axis and positioned with respect to the adjacent electrodes of said first pair such that a predetermined portion of the periphery of said electrode is spaced a predetermined distance from a corresponding portion of said adjacent electrodes, whereby a change in capacitance may be sensed with respect to the two orthogonal axes when the sensor is touched by a human operator.
Claim 21
Dependent Claim
24 words
A sensor for a capacitive activated transducer as set forth in claim 16 wherein said electrodes comprise an etched copper pattern overlaying said substrate.
Claim 22
Dependent Claim
21 words
A sensor for a capacitive activated transducer as set forth in claim 17 including a protective shield overlaying said copper pattern.
Claim 23
Dependent Claim
32 words
A sensor for a capacitive activated transducer as set forth in claim 17 wherein said first and second pairs of copper electrodes have a shape whose outer peripheries form a ring-shaped configuration.
References Cited (Backward Citations)
US2219497A
Cited
US2546307A
Cited
US3582827A
Cited
US3497617A
Cited
US3773989A
Cited
US3737670A
Cited
US3751612A
Cited
US4001807A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-24 | 1982-01-23 | 1982-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-24 | 1986-01-23 | 1986-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-24 | 1990-01-23 | 1990-07-25 | $7700.00 | Window Closed / Lapsed |