METHOD AND APPARATUS FOR DETECTING TWO SIMULTANEOUS TOUCHES AND GESTURES ON A RESISTIVE TOUCHSCREEN
First Claim
1. A resistive touchscreen system, comprising:
- a substrate comprising a first conductive coating;
a coversheet comprising a second conductive coating, the substrate and the coversheet positioned proximate each other such that the first conductive coating faces the second conductive coating, the substrate and coversheet being electrically disconnected with respect to each other in the absence of a touch;
a first set of electrodes formed on the substrate for establishing voltage gradients in a first direction;
a second set of electrodes formed on the coversheet for establishing voltage gradients in a second direction, the first and second directions being different; and
a controller configured to bias the first and second sets of electrodes in first and second cycles, the controller further configured to sense a bias load resistance associated with at least one of the sets of electrodes, the bias load resistance having a reference value associated with no touch, a decrease in the bias load resistance relative to the reference value indicating two simultaneous touches.
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Accused Products
Abstract
Resistive touchscreen system has substrate and coversheet with first and second conductive coatings. The substrate and coversheet are positioned proximate each other such that the first conductive coating faces the second conductive coating. The substrate and coversheet are electrically disconnected with respect to each other in the absence of a touch. First set of electrodes is formed on the substrate for establishing voltage gradients in first direction. Second set of electrodes is formed on the coversheet for establishing voltage gradients in second direction wherein the first and second directions are different. Controller biases the first and second sets of electrodes in first and second cycles and senses a bias load resistance associated with at least one of the sets of electrodes. The bias load resistance has a reference value associated with no touch. A decrease in the bias load resistance relative to the reference value indicates two simultaneous touches.
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Citations
20 Claims
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1. A resistive touchscreen system, comprising:
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a substrate comprising a first conductive coating; a coversheet comprising a second conductive coating, the substrate and the coversheet positioned proximate each other such that the first conductive coating faces the second conductive coating, the substrate and coversheet being electrically disconnected with respect to each other in the absence of a touch; a first set of electrodes formed on the substrate for establishing voltage gradients in a first direction; a second set of electrodes formed on the coversheet for establishing voltage gradients in a second direction, the first and second directions being different; and a controller configured to bias the first and second sets of electrodes in first and second cycles, the controller further configured to sense a bias load resistance associated with at least one of the sets of electrodes, the bias load resistance having a reference value associated with no touch, a decrease in the bias load resistance relative to the reference value indicating two simultaneous touches. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for detecting two simultaneous touches on a resistive touchscreen system, comprising;
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connecting controller electronics to first and second electrodes that are electrically connected to opposite sides of a first conductive coating; comparing a bias load resistance measured between the first and second electrodes to a threshold level; and identifying a multiple-touch state when the bias load resistance is less than the threshold level. - View Dependent Claims (16, 17, 18, 19)
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20. A resistive touchscreen system, comprising:
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a substrate comprising a first conductive coating having a perimeter; a coversheet comprising a second conductive coating, the substrate and the coversheet positioned proximate each other such that the first conductive coating faces the second conductive coating, the substrate and coversheet electrically disconnected with respect to each other in the absence of a touch; first and second electrode structures electrically connected to two different portions of the perimeter; and a controller configured to measure a bias load resistance between the first electrode structure and the second electrode structure, the bias load resistance having a reference value associated with no touch, a decrease in the bias load resistance relative to the reference value indicating two simultaneous touches.
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Specification