Touch sensor and controller
First Claim
1. A touch sensor for detecting the variable force and the force-weighted average position of external forces exerted against the outer surface of the touch sensor, comprising:
- an X insulating substrate forming a first outer surface of the touch sensor;
a plurality of X conductive traces deposited on the X substrate;
an X fixed resistor deposited on the X substrate and connected to each of the X conductive traces thereby providing a fixed resistance between adjacent X conductor traces;
two X terminals connected to either end of the X fixed resistor for interfacing the X fixed resistor to external circuitry;
a Y insulating substrate forming a second outer surface of the touch sensor;
a plurality of Y conductive traces deposited on the Y substrate and arranged in orthogonal orientation to the X conductive traces;
a Y fixed resistor deposited on the Y substrate and connected to each of the Y conductive traces thereby providing a fixed resistance between adjacent Y conductor traces;
two Y terminals connected to either end of the Y fixed resistor for interfacing the Y fixed resistor to external circuitry; and
a through-mode force variable resistor layer positioned between the X conductive traces and the Y conductive traces and providing a resistance from at least one X conductive trace to at least one Y conductive trace that decreases with increasing external force.
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0 Petitions
Accused Products
Abstract
A touch sensor is disclosed that senses the two-dimensional position and pressure of an object 34, such as a stylus or finger, that is touching its surface. The sensor is comprised of two insulating substrates 28 and 29 which extend over the area to be sensed. A first fixed resistor 33 establishes a potential gradient over the first substrate 29 in a first, or X, position dimension. A second fixed resistor 32 establishes a potential gradient over the second substrate 28 in a second, or Y, position dimension. Between the substrates is a force variable resistor 42 that changes its local resistance under the touch point as a function of the touch pressure. Two touch controllers are also disclosed that comprise the touch sensor 50 and an electronic circuit that accurately measures the resistance values of the touch sensor. The touch controllers output three signals: the X position, the Y position, and the pressure of the touch point. The first touch controller uses a current regulator 51 to supply a constant current through the touch sensor. The second touch controller uses a voltage regulator 67 to supply a constant voltage across the touch sensor.
453 Citations
17 Claims
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1. A touch sensor for detecting the variable force and the force-weighted average position of external forces exerted against the outer surface of the touch sensor, comprising:
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an X insulating substrate forming a first outer surface of the touch sensor; a plurality of X conductive traces deposited on the X substrate; an X fixed resistor deposited on the X substrate and connected to each of the X conductive traces thereby providing a fixed resistance between adjacent X conductor traces; two X terminals connected to either end of the X fixed resistor for interfacing the X fixed resistor to external circuitry; a Y insulating substrate forming a second outer surface of the touch sensor; a plurality of Y conductive traces deposited on the Y substrate and arranged in orthogonal orientation to the X conductive traces; a Y fixed resistor deposited on the Y substrate and connected to each of the Y conductive traces thereby providing a fixed resistance between adjacent Y conductor traces; two Y terminals connected to either end of the Y fixed resistor for interfacing the Y fixed resistor to external circuitry; and a through-mode force variable resistor layer positioned between the X conductive traces and the Y conductive traces and providing a resistance from at least one X conductive trace to at least one Y conductive trace that decreases with increasing external force. - View Dependent Claims (2, 3, 4, 5, 6, 7, 12, 13, 14, 15, 16, 17)
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8. A touch sensor for detecting the variable force and the force-weighted average position of external forces exerted against the outer surface of the touch sensor, comprising:
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an X insulating substrate forming a first outer surface of the touch sensor; an X resistor layer deposited on the X substrate, having a fixed resistance within the plane of the touch sensor and having a force variable resistance normal to the plane of the touch sensor; two X terminals connected to each of two opposing sides of the X resistor layer for interfacing the X resistor layer to external circuitry; a Y insulating substrate forming a second outer surface of the touch sensor; a Y resistor layer deposited on the Y substrate, having a fixed resistance within the plane of the touch sensor and having a force variable resistance normal to the plane of the touch sensor; and two Y terminals connected to each of two opposing sides of the Y resistor layer and oriented in an orthogonal direction to the X terminals for interfacing the Y resistor layer to external circuitry, whereby an external force exerted against an outer surface of the touch sensor causes a region of the X resistor layer to contact a region of the Y resistor layer and the resistance between the X resistor layer and the Y resistor layer decreases with increasing force. - View Dependent Claims (9, 10, 11)
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Specification