Switch for sensing proximity of an operator
First Claim
1. A device having at least two states comprising:
- a. a reference element;
b. an active element having alterable electrical characteristics responsive to the proximity of an operator; and
c. means for,(i) driving said reference element and said active element at a chosen level and producing signals therefrom, and for,(ii) comparing the signal from said reference element and the signal from said active element and generating a comparison signal therefrom, and for,(iii) altering the state of said device reponsive to said comparison signal.
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Accused Products
Abstract
A proximity switch in which the electronic characteristics of a liquid crystal display are monitored relative to a reference liquid crystal display to determine when an operator has come into proximity thereto. A controller monitors the display elements, liquid crystal displays, respective capacitances or inductance and when an operator comes into proximity to an electrode in the display element, the controller senses this proximity due to the change in capacitance or inductance of the element. This sensing allows the controller to recognize when a change of state is desired by the operator. The use of the reference element allows the controller to respond only to operator proximity and not to noise caused by changes in the environment, such as temperature.
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Citations
17 Claims
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1. A device having at least two states comprising:
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a. a reference element; b. an active element having alterable electrical characteristics responsive to the proximity of an operator; and c. means for, (i) driving said reference element and said active element at a chosen level and producing signals therefrom, and for, (ii) comparing the signal from said reference element and the signal from said active element and generating a comparison signal therefrom, and for, (iii) altering the state of said device reponsive to said comparison signal. - View Dependent Claims (2, 3, 4)
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5. An operator interface comprising:
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a. a reference element; b. an active element having alterable electrical characteristics responsive to the proximity of an operator; and c. control means having at least two states and having, (i) means for supplying a preselected signal to said reference element and generating a signal therefrom, (ii) means for supplying a chosen signal to said active element and generating a signal therefrom, (iii) means for comparing the signal from said reference element to the signal from said active element, and generating a comparison signal, and (iv) means for altering the state of said control means according to said comparison signal. - View Dependent Claims (6, 7, 8, 9, 10, 11)
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12. A method of operating an operator interface having at least two states, comprising the steps of:
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a. driving a reference element at a chosen level; b. driving a display element having alterable electrical characteristics according to the proximity of an operator; c. comparing signals from said reference element and said display element and generating a comparison signal therefrom; and
,d. altering states of said operator interface according to said comparison signal. - View Dependent Claims (13, 14)
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15. A proximity switch having at least two states comprised of:
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a. a first segment; b. a second segment having alterable electrical characteristics responsive to the proximity of an operator; and c. means for, (i) driving said first segment and said second segment at a selected level and generating signals therefrom, and for, (iii) altering the state of said proximity switch according to difference between the signal of said first element and the signal of said second element. - View Dependent Claims (16, 17)
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Specification