Touch screen based topological mapping with resistance framing design
First Claim
Patent Images
1. A touchscreen system comprising:
- (a) a rectangular electrically conductive area;
(b) a cover sheet positioned over an exterior surface of the electrically conductive area;
(c) a complete set of four electrodes, one of the electrodes attached to each corner of the electrically conductive area and connected to an electrical power source;
(d) a band applied to the substrate and framing the electrically conductive area having a conductivity within a range that enables unique non-linear mapping from electrical measurements made on a surface of the cover sheet to a set of Cartesian coordinates;
(e) an electric circuit that measures a potential of a selected point on the conductive area when brought into contact therewith;
(f) a controller that sequentially switches electrical potential from the power source to a first subset of said electrodes thereby establishing a first non-uniform electrical potential distribution on the conductive area, and then to a second subset of said electrodes thereby establishing a second electrical potential distribution on the conductive area; and
(g) a processor that processes each set of potential measurements of said first and second electrical potential distributions from the electric circuit and uses an electrical measurement from each of the first and second electrical potential distributions corresponding to the selected point to perform unique non-linear mapping to determine a location of the selected point.
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Abstract
A new touch screen is based upon the mapping of coordinates from an equipotential space defined by a simple set of screen electrodes to some other, more useful coordinates, such as Cartesian. The key idea is that unique coordinate mapping can be achieved with each sensing pair of electronic readings. A new sensor is described with a band of intermediate conductivity framing the sensor area. This sensor can be used advantageously either as a standalone with uniform equipotential distributions or in connection with the mapping concepts discussed herein with non-uniform distributions.
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Citations
11 Claims
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1. A touchscreen system comprising:
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(a) a rectangular electrically conductive area;
(b) a cover sheet positioned over an exterior surface of the electrically conductive area;
(c) a complete set of four electrodes, one of the electrodes attached to each corner of the electrically conductive area and connected to an electrical power source;
(d) a band applied to the substrate and framing the electrically conductive area having a conductivity within a range that enables unique non-linear mapping from electrical measurements made on a surface of the cover sheet to a set of Cartesian coordinates;
(e) an electric circuit that measures a potential of a selected point on the conductive area when brought into contact therewith;
(f) a controller that sequentially switches electrical potential from the power source to a first subset of said electrodes thereby establishing a first non-uniform electrical potential distribution on the conductive area, and then to a second subset of said electrodes thereby establishing a second electrical potential distribution on the conductive area; and
(g) a processor that processes each set of potential measurements of said first and second electrical potential distributions from the electric circuit and uses an electrical measurement from each of the first and second electrical potential distributions corresponding to the selected point to perform unique non-linear mapping to determine a location of the selected point. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A touchscreen having a transparent substrate completely coated with an electrically conductive material thereby providing a generally rectangular conductive area having a conductivity, the touchscreen comprising:
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a complete set of four electrodes, one of the electrodes positioned at each corner of the conductive area; and
a discrete rectangular band including four strips applied to the substrate, each strip electrically coupled to the electrodes and the conductive area, each strip having a substantially uniform width and a conductivity, the band framing the electrically conductive area, wherein a ratio of the band conductivity to the conductive area conductivity multiplied by a ratio of the band strip width to the conductive area dimension measured in the same direction as the band strip width is greater than 0.25 and less than 10. - View Dependent Claims (10)
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11. A touchscreen system comprising:
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a touchscreen having a transparent substrate completely coated with an electrically conductive material thereby providing a generally rectangular conductive area having a conductivity, the touchscreen comprising;
a complete set of four electrodes, one of the electrodes positioned at each corner of the conductive area; and
a discrete rectangular band including four strips applied to the substrate, each strip electrically coupled to the electrodes and the conductive area, each strip having a substantially uniform width and a conductivity, the band framing the electrically conductive area, wherein a ratio of the band conductivity to the conductive area conductivity multiplied by a ratio of the band strip width to the conductive area dimension measured in the same direction as the band strip width is greater than 0.25 and less than 10; and
an electric circuit that measures a potential of a selected point on the conductive area when brought into contact therewith;
a controller that sequentially switches electrical potential from the power source to a first subset of said electrodes thereby establishing a first non-uniform electrical potential distribution on the conductive area, and then to a second subset of said electrodes thereby establishing a second electrical potential distribution on the conductive area; and
a processor that processes each set of potential measurements of said first and second electrical potential distributions from the electric circuit and uses an electrical measurement from each of the first and second electrical potential distributions corresponding to the selected point to perform unique non-linear mapping to determine a location of the selected point.
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Specification