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US 5,708,460 AGranted
Touch screen
AssigneeAVI Systems, Inc.
InventorsThomas M. Young, William Martin Becker, Joseph Shamash
Life of this patent
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AssigneeAVI Systems, Inc.
InventorsThomas M. Young, William Martin Becker, Joseph Shamash
Estimating the term…
A touch screen or touch panel wherein there is a monitoring of relative distribution of force via one or more, preferably symmetrically positioned, sensors such as strain gage sensors. The strain gage sensors are positioned such that bending strain on the touch screen, engendered by touch, is detected by the one or more strain gages and accurately measured by an electronic controller, connected to the strain gage(s). The electronic controller, or associated hardware, is programmed to relate relative bending force to a unique position on the screen and is a charge balancing and multiplying analog-to-digital converter which provides accurate position determination, even with very low forces and with very minor differentiation in position related forces. A sum and divide analog-to-digital converter uses charge balancing and integration, with the balance charge coming from the plus and minus sum of the corners (wherein four sensors are positioned at the corners of a square or rectangular display), and the input signal is the difference between two sides of the display panel. This, in effect, results in the input signal being divided by the sum signal and the sum of charge counts over a fixed interval, resulting in the output value and unique position determination. A unique mounting structure for flat panel displays includes using the flat panel as the bending beam and wherein a circuit board mounted behind the flat panel transmits forces to sensors mounted on the circuit board.
A touch screen comprising sensors for monitoring relative distribution of force thereon, said sensors being positioned relative to the touch screen such that bending strain on the touch screen, engendered by touch, is detected by the sensors, wherein said sensors transmit one or more input signals to a charge balancing and multiplying analog to digital converter configured to relate bending force to an identifiable unique position on the screen, the charge balancing and multiplying analog to digital converter comprising a sum and divide analog-to-digital converter using charge balancing and integration, wherein said sensors provide sensing and valuation of touch forces on said screen, from opposite sides of said screen, with conversion of the valuation of the touch forces from opposite sides of the screen to separate proportional charge signals, whereby a balance charge comes from the plus and minus sum of the sensing of touch forces on said screen from opposite sides thereof, and means for converting the balance charge to a position on the screen, wherein said screen is quadrilateral and wherein said sensors include at least four sensors positioned at the four corners of the quadrilateral screen, wherein an input signal is the difference between proportional charge signals from two opposite sides of the screen and wherein the input signal is divided by the sum signal and the sum of charge counts over a fixed interval, resulting in an output value used by the means for converting the balance charge to a position on the screen.
A touch screen device comprising:
Dependencies are inferred from the claim text.