Elo Touchsystems, Inc.

Other

Semiconductor Components Industries, LLC

Elo Touch Solutions, Inc.

Joe Henry Babb

Geoffrey D Wilson

Joel Christopher Kent

Robert L Brennan

Hamid Sheikhzadeh Nadjar

James R Wynne, Jr

Steven W Haungs

A bending wave touch system includes at least one sensor and a touchscreen controller. The at least one sensor is coupled to a substrate and is responsive to vibrations in the substrate. The at least one sensor outputs signals. The controller receives the signals from the at least one sensor and identifies touch coordinates based on high frequency components of the signals when a touch on the substrate includes at least one of a tap, a drag and a lift-off. The controller identifies a status of a hold condition of the touch based on at least two different time averages of low frequency components of the signals.

Method and apparatus for detecting hold condition on an acoustic touch surface

A general method is described for producing an inexpensive touchscreen system that provides accurate positional information and compensates for manufacturing variations without complicated sensor arrangements. Utilizing a set of sensed signals that are unique to each location on the touchscreen sensor, equations for X and Y are derived via curve fitting methods. The coefficients of the equations are stored with the sensor. During touchscreen operation the coefficients are used to calculate X and Y to the desired accuracy directly and independently.

Algorithmic compensation system and method therefor for a touch sensor panel

A method and apparatus for making a five-wire touch-screen compatible with a four-wire interface is provided. A non-microprocessor-based converter is used that can be integrated directly into the touch-screen housing or the screen-to-interface ribbon cable. In one aspect of the converter, an analog logic and switching element routes the reference voltage from the four-wire controller to a current injection control device. The current injection control device applies a constant current to the outermost screen member of the touch-screen. When the outermost screen member and the innermost screen member of the touch screen come into contact, the current from the outermost member is injected into the resistive coating of the innermost member at the point of contact. The injected current is distributed to the four contact electrodes of the innermost member in direct proportion to the coordinates of the point of contact. Each of the four currents is converted to a voltage and routed to a logic amplifier that outputs a pair of voltages proportional to the x- and y-coordinates of the compression point. In another aspect of the converter, a feedback circuit is provided that ensures that the voltages proportional to the x- and y-coordinates continuously track the reference voltage. As a result of this feedback circuit, the coordinate measurement system is both stable and reliable.

Low current four-wire interface for five-wire resistive touch-screen

Algorithmic compensation system and method therefor for a touch sensor

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Knoxville, TN, United States of America

Joe Henry Babb