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 having a first resistance;
a coversheet comprising a second conductive coating having a second resistance, 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 two different cycles, the controller further configured to sense a bias current associated with at least one of the first resistance and the second resistance, the bias current having a reference value associated with no touch, an increase in the bias current relative to the reference value indicating two simultaneous touches.
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Accused Products
Abstract
Resistive touchscreen system has a substrate with a first conductive coating having a first resistance and a coversheet with a second conductive coating having a second resistance. 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 and second sets of electrodes for establishing voltage gradients in first and second directions are formed on the substrate and the coversheet, respectively. A controller biases the first and second sets of electrodes in two different cycles. The controller senses a bias current associated with at least one of the first and second resistances. The bias current has a reference value associated with no touch. An increase in the bias current relative to the reference value indicates two simultaneous touches.
100 Citations
20 Claims
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1. A resistive touchscreen system, comprising:
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a substrate comprising a first conductive coating having a first resistance; a coversheet comprising a second conductive coating having a second resistance, 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 two different cycles, the controller further configured to sense a bias current associated with at least one of the first resistance and the second resistance, the bias current having a reference value associated with no touch, an increase in the bias current relative to the reference value indicating two simultaneous touches. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for detecting two simultaneous touches on a resistive touchscreen system, comprising:
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biasing a resistive touchscreen to generate voltage gradients along a first direction and a second direction; detecting a first bias current associated with the first direction, the first bias current associated with a non-zero first reference value that is representative of a bias current along the first direction when no touch is present on the resistive touchscreen; detecting a second bias current associated with the second direction, the second bias current associated with a non-zero second reference value that is representative of a bias current along the second direction when no touch is present on the resistive touchscreen; and determining that two simultaneous touches are present on the resistive touchscreen when one of the first and second bias currents is greater than the first and second reference values, respectively. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification