Detecting a ‘no touch’ state of a touch screen display
First Claim
1. In a touch-screen display system for generating pixel coordinate estimates responsive to a user touching a display screen, an apparatus for enabling detection of a “
- no touch”
state of said touch-screen display system comprising;
at least one bus bar;
at least one driver electrically connected to said at least one bus bar to selectively switch said at least one bus bar between at least two of a plurality of electrical potentials; and
at least one shunt electrically connected across said at least one driver.
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Accused Products
Abstract
An enhanced touch-screen display system is disclosed for generating pixel coordinate estimates corresponding to a location on a display screen touched by a user. The system is an analog resistive touch-screen display system having a processor and associated software algorithms to allow for the calibration and validation of pixel coordinate estimates as an integral part of the real-time generation of the pixel coordinate estimates. Multiple calibrated pixel coordinate estimates are generated and processed at a pre-defined sampling rate to determine a valid pixel position to minimize sampling delays due to settling times. The x-axis position is also validated before the system attempts to generate a y-axis position to avoid the wasted time for generating y-axis estimates when x-axis estimates are corrupted. Noisy estimates are inherently reduced in the touch-screen display system by providing shunts across certain drivers in the system that also allow for detection of a “no touch” state.
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Citations
31 Claims
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1. In a touch-screen display system for generating pixel coordinate estimates responsive to a user touching a display screen, an apparatus for enabling detection of a “
- no touch”
state of said touch-screen display system comprising;at least one bus bar; at least one driver electrically connected to said at least one bus bar to selectively switch said at least one bus bar between at least two of a plurality of electrical potentials; and at least one shunt electrically connected across said at least one driver. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
- no touch”
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16. In a touch-screen display system for generating pixel coordinate estimates responsive to a user touching a display screen, a method for enabling detection of a “
- no touch”
state of said touch-screen display system comprising;selectively switching at least one reference point of at least one axis of said touch-screen display system between at least two of a plurality of electrical potentials by employing electrical driving techniques and electrical shunting techniques. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
- no touch”
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27. A method of determining whether or not a touch screen has been touched comprising the steps of:
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reading a first coordinate of a coordinate pair at a first time; consecutively reading the same coordinate at a second time; determining if the absolute value of the difference between the first coordinate and the consecutive coordinate is less than a predetermined value; and quantifying, responsive to the difference determining step the coordinate position as a function of the first or the consecutive coordinate.
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28. Apparatus determining whether a touch screen has been touched comprising:
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means for reading a first coordinate of a coordinate pair at a first time; means for consecutively reading the same coordinate at a second time; means for determining if the absolute value of the difference between the first coordinate and the consecutive coordinate is less than a predetermined value; and means, response to the determining means, for quantifying the coordinate position as a function of the first or the consecutive coordinate. - View Dependent Claims (29)
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30. In a touch-screen display system for generating pixel coordinate estimates responsive to a user touching a display screen, an apparatus for enabling detection of a “
- no touch”
state of said touch-screen display system comprising;at least one bus bar; at least one driver electrically connected to said at least one bus bar to selectively switch said at least one bus bar between at least two of a plurality of electrical potentials wherein the at least one driver is selected to have an off state impedance establishing a pre-determined discharge rate.
- no touch”
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31. In a touch-screen display system for generating pixel coordinate estimates responsive to a user touching a display screen, an apparatus for enabling detection of a “
- no touch”
state of said touch-screen display system comprising;at least one bus bar; at least one driver electrically connected to said at least one bus bar to selectively switch said at least one bus bar between at least two of a plurality of electrical potentials wherein the at least one driver is controlled to establish pre-determined discharge rates.
- no touch”
Specification