Windshield moisture sensor
First Claim
1. A sensor for detecting moisture comprising:
- a dielectric substrate;
first and second electroconductive members positioned adjacent to each other and secured along a first major surface of said substrate and spaced apart a first predetermined distance, wherein adjacent portions of said first and second members have exposed, uncoated electroconductive surfaces;
first and second electroconductive leads extending from said first and second electroconductive members, respectively, and secured along said substrate surface wherein said leads are spaced apart a second predetermined distance and portions of said leads have exposed, uncoated electroconductive surfaces;
means to permit electrical connection of said leads to a signal generator; and
means to permit electrical connection of said leads to a monitoring means capable of detecting variations in a predetermined characteristic of said sensor, wherein said first predetermined distance is sufficiently different from said second predetermined distance so that said monitored characteristic of said sensor when said leads are electrically interconnected by moisture therebetween is measurably different from said monitored characteristic when said electroconductive members or said electroconductive members and leads are electrically interconnected by moisture therebetween.
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Accused Products
Abstract
A moisture sensor to sense rain on a windshield includes sensor members and leads on the outboard surface of the windshield. The members and leads are uncoated and directly exposed to any moisture accumulation on the sensor. Leads connect the sensor to a controller which includes a signal generator and sensor monitor. The relative spacing between the leads as compared to the spacing between the sensor members is such that the impedance of the sensor when the leads are electrically interconnected by moisture is measurably different from the sensor impedance when said members or said members and leads are electrically interconnected. In response to the latter signal, the windshield wipers are actuated.
79 Citations
29 Claims
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1. A sensor for detecting moisture comprising:
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a dielectric substrate; first and second electroconductive members positioned adjacent to each other and secured along a first major surface of said substrate and spaced apart a first predetermined distance, wherein adjacent portions of said first and second members have exposed, uncoated electroconductive surfaces; first and second electroconductive leads extending from said first and second electroconductive members, respectively, and secured along said substrate surface wherein said leads are spaced apart a second predetermined distance and portions of said leads have exposed, uncoated electroconductive surfaces; means to permit electrical connection of said leads to a signal generator; and means to permit electrical connection of said leads to a monitoring means capable of detecting variations in a predetermined characteristic of said sensor, wherein said first predetermined distance is sufficiently different from said second predetermined distance so that said monitored characteristic of said sensor when said leads are electrically interconnected by moisture therebetween is measurably different from said monitored characteristic when said electroconductive members or said electroconductive members and leads are electrically interconnected by moisture therebetween. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A sensor for detecting moisture comprising:
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a dielectric substrate; first and second electroconductive members positioned adjacent to each other and secured along a first major surface of said substrate and spaced apart a first predetermined distance, wherein adjacent portions of said first and second members have exposed, uncoated electroconductive surfaces; first and second electroconductive leads extending from said first and second electroconductive members, respectively, and secured along said substrate surface wherein said leads are spaced apart a second predetermined distance and portions of said leads have exposed, uncoated electroconductive surfaces; a signal generator electrically interconnected to said leads; and means to monitor a predetermined characteristic of said sensor, wherein said first predetermined distance is sufficiently different from said second predetermined distance so that said monitored characteristic of said sensor when said leads are electrically interconnected by mositure therebetween is measurably different from said monitored characteristic when said electroconductive members or said electroconductive members and leads are electrically interconnected by moisture therebetween. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A sensor for detecting moisture comprising:
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a dielectric substrate; first and second electroconductive members positioned adjacent to each other and secured along a first major surface of said substrate and spaced apart a first predetermined distance, wherein adjacent portions of said first and second members have exposed, uncoated electroconductive surfaces; and first and second electroconductive leads extending from said first and second electroconductive members, respectively, and secured along said substrate surface wherein said leads are spaced apart a second predetermined distance and portions of said leads have exposed, uncoated electroconductive surfaces, wherein said first predetermined distance is sufficiently different from said second predetermined distance so that a predetermined electrical characteristic of said sensor indicates the presence or absence of moisture on selected portions of said sensor.
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23. A method of detecting moisture on a dielectric substrate comprising:
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positioning and securing first and second electroconductive members adjacent to each other along a first major surface of said substrate and spaced apart a first predetermined distance, wherein adjacent portions of said first and second members have exposed, uncoated electroconductive surfaces; extending and securing first and second electroconductive leads from said first and second electroconductive members, respectively, along said substrate surface, wherein said leads are spaced apart a second predetermined distance and portions of said leads have exposed, uncoated electroconductive surfaces; passing an electrical signal through said sensor; and
monitoring variations in a predetermined characteristic of said sensor, wherein said first predetermined distance is sufficiently different from said second predetermined distance so that said monitored characteristic of said sensor when said leads are electrically connected by moisture therebetween is measurably different from said monitored characteristic when said members are interconnected by moisture therebetween. - View Dependent Claims (24, 25, 26)
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27. A sensor for detecting moisture comprising:
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a dielectric substrate; first and second electroconductive members secured to a first major surface of said substrate and positioned adjacent to each other and spaced apart a predetermined distance, wherein adjacent portions of said first and second members have exposed, uncoated electroconductive surfaces; first and second electroconductive leads secured to said first major surface of said substrate and extending from said first and second electroconductive members, respectively, wherein said leads are spaced apart a second predetermined distance different from said first predetermined distance, and portions of said leads have exposed uncoated electroconductive surfaces, said sensor having a first electrical characteristic when moisture interconnects only said first and second leads, indicating a first operating condition, and a second electrical characteristic, different from said first electrical characteristic when moisture at least interconnects said first and second electroconductive members, indicating a second operating condition; and means to permit electrical connection of said leads to controller having a signal generator and a signal monitoring means capable of detecting a change in the electrical characteristic of said sensor from said first electrical characteristic to said second electrical characteristic.
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28. A sensor for detecting moisture comprising:
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a dielectric substrate; first and second electroconductive members secured to a first major surface of said substrate and positioned adjacent to each other and spaced apart a predetermined distance wherein adjacent portions of said first and second members have exposed uncoated electroconductive surfaces; first and second electroconductive leads secured to said first major surface of said substrate and extending from said first and second electroconductive members, respectively, wherein said leads are spaced apart a second predetermined distance different from said first predetermined distance and portions of said leads have exposed uncoated electroconductive surfaces, said sensor having a first electrical characteristic when moisture interconnects only said first and second leads, indicating a first operating condition, and a second electrical characteristic, different from said first electrical characteristic, when moisture at least interconnects said first and second electroconductive members, indicating a second operating condition; and a controller electrically connected to said leads and having a signal generating means and a signal monitoring means, wherein said monitoring means of capable of detecting a change in the electrical characteristic of said sensor from said first electrical characteristic to said second electrical characteristic.
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29. A method of detecting moisture on a dielectric substrate comprising:
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securing first and second electroconductive members to a first major surface of said substrate, said members being adjacent to each and spaced apart a first predetermined distance wherein adjacent portions of said first and second members having exposed uncoated electroconductive surfaces; securing first and second electroconductive leads extending from said first and second electroconductive members, respectively, to said substrate surface wherein said leads are spaced apart a second predetermined distance different from said first predetermined distance and portions of said leads have exposed, uncoated electroconductive surfaces, and further wherein said sensor has a first electrical characteristic when moisture interconnects only said first and second electroconductive leads, indicating a first operating condition, and a second electrical characteristic, different from said first electrical characteristic, when moisture at least interconnects said first and second electroconductive members, indicating a second operating condition; passing an electrical signal through said sensor; monitoring said electrical characteristic of said sensor; and activating means to remove moisture from said sensor when said monitoring step detects said second electrical characteristic and deactivating said removal means when said monitoring step detects said first electrical characteristic.
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Specification