US4760490A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Proximity switch device
Assignee: Honda Motor Co Ltd
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Filing: 1986-11-12
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Granted: 1988-07-26
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Expires: 2006-11-12
Abstract
Abstract A proximity switch device adapted to provide a contactless switching function for an electric device, such as a radio mounted in a vehicle when approached by an object, such as a driver's hand including a floating capacitance detector and an amplified oscillator circuit for converting a change in floating capacitance into a change in frequency signal, a voltage fluctuation detecting circuit for detecting an approach of the object based upon said frequency signal, and a flip-flop switch for switching on and off the electric device whenever an output signal indicating the approach of the object is produced.
Inventors
- 👤 Eiji Murao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:34
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/22; G08B13/26; H; H03; H03K; H03K17/00; H03K17/94; H03K17/945; H03K17/955
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
215 words
A proximity switch characterized in that it comprises means for converting a change in floating capacitance between a sensor comprising an electrode plate and object to be detected into a change in frequency signal; means for detecting an approach of said object in response to the attenuation of said frequency signal; means for alternately switching on and off an electric device every time when an output signal indicative of detection of said object is produced; wherein said switch device comprises an oscillator for producing a constant frequency signal; a network connected to an output of said oscillator and having a sensor connected to a point between resistors in the network; a band-pass filter and amplifier for noise suppressing and amplifying R. F. output voltage from said network; a detector for detecting the amplified output signal from said band-pass filter and amplifier; a voltage fluctuation detecting circuit for sensing a decrease of said detected voltage signal that exceeds a preselected limit; a flip-flop which changes state in response to an output signal of said voltage fluctuation detecting circuit; a switching element which is turned on and off depending upon an output signal of said flip-flop; and a relay which is energized when said switching element is turned on to perform the switch-on of the electric device.
Claim 2
Dependent Claim
215 words
A proximity switch characterized in that it comprises means for converting a change in floating capacitance between a sensor comprising an electrode plate and object to be detected into a change in frequency signal; means for detecting an approach of said object in response to the attenuation of said frequency signal; means for alternately switching on and off an electric device every time when an output signal indicative of detection of said object is produced; wherein said switch device comprises an oscillator for producing a constant frequency signal; a network connected to an output of said oscillator and having a sensor connected to a point between resistors in the network; a band-pass filter and amplifier for noise suppressing and amplifying R. F. output voltage from said network; a detector for detecting the amplified output signal from said band-pass filter and amplifier; a voltage fluctuation detecting circuit for sensing a decrease of said detected voltage signal that exceeds a preselected limit; a flip-flop which changes state in response to an output signal of said voltage fluctuation detecting circuit; a switching element which is turned on and off depending upon an output signal of said flip-flop; and a relay which is energized when said switching element is turned on to perform the switch-on of the electric device.
Claim 3
Dependent Claim
73 words
The proximity switch device according to claim 1 wherein said voltage fluctuation detecting circuit includes a first amplifier for amplifying the output voltage of said detector; a second amplifier for amplifying the same output voltage and introducing a certain time delay; a comparator for comparing the both amplified output voltages; and a decision circuit for determining whether or not the time duration of the output signal from said comparator exceeds a preselected value.
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) | 1991-07-26 | 1992-01-25 | 1992-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-26 | 1996-01-25 | 1996-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-26 | 2000-01-25 | 2000-07-26 | $7700.00 | Window Closed / Lapsed |