Touch tablet data device
First Claim
1. Structure for use in inputing the X and Y coordinates of a selected contact point into a computer system, graphic display unit or similar structure, comprisinga first sheet of flexible insulating material containing a first surface and a second surface;
- a second sheet of flexible insulating material containing a first surface and a second surface;
resistive material formed on the first surface of said first sheet of insulating material;
resistive material formed on the first surface of said second sheet of insulating material;
a first conductive strip and a second conductive strip formed on two noncontacting edges of the four edges of said first surface of said first sheet adjacent to and in electrical contact with said resistive materials on said first sheet;
a first conductive strip and a second conductive strip formed on two noncontacting edges of the four edges of said first surface of said second sheet adjacent to and in electrical contact with the resistive material on said second sheet;
means for applying a voltage from the first to the second conductive strip through said resistive material on said first sheet;
means, electrically connected to the first and the second conductive strips on said second sheet, for connecting said two conductive strips on said second sheet to the input lead of a means for amplifying; and
means for arranging said first sheet and said second sheet such that said first and second conductive strips on said first sheet are orthogonal to said first and second conductive strips on said second sheet and such that the resistive material on said first sheet faces the resistive material on said second sheet but is separated therefrom by a selected space.
3 Assignments
0 Petitions
Accused Products
Abstract
A touch tablet for use in entering data into a computer or graphics display device comprises a first four-sided sheet containing a resistive material on one surface thereof, a second four-sided sheet containing a resistive material on one surface thereof and a spacer for holding the first sheet apart from the second sheet. The first sheet is oriented relative to the second sheet such that the resistive material on one of the two sheets faces the resistive material on the other sheet. Each sheet contains conductive strips formed on two of the four sides of the sheet in contact with the resistive material. A potential is applied across the conductive strips on one of the two sheets. The input lead to an output amplifier is connected to the two conductive strips formed on the other of the two sheets. A user presses the first sheet into conduct with the second sheet and the output voltage from the output amplifier is representative of one of the two coordinates of the point of contact between the two sheets. By connecting the output amplifier to the two conductive strips on the second sheet rather than merely to one conductive strip as in the prior art, the sensitivity of the tablet to noise is reduced and system performance is improved.
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Citations
4 Claims
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1. Structure for use in inputing the X and Y coordinates of a selected contact point into a computer system, graphic display unit or similar structure, comprising
a first sheet of flexible insulating material containing a first surface and a second surface; -
a second sheet of flexible insulating material containing a first surface and a second surface; resistive material formed on the first surface of said first sheet of insulating material; resistive material formed on the first surface of said second sheet of insulating material; a first conductive strip and a second conductive strip formed on two noncontacting edges of the four edges of said first surface of said first sheet adjacent to and in electrical contact with said resistive materials on said first sheet; a first conductive strip and a second conductive strip formed on two noncontacting edges of the four edges of said first surface of said second sheet adjacent to and in electrical contact with the resistive material on said second sheet; means for applying a voltage from the first to the second conductive strip through said resistive material on said first sheet; means, electrically connected to the first and the second conductive strips on said second sheet, for connecting said two conductive strips on said second sheet to the input lead of a means for amplifying; and means for arranging said first sheet and said second sheet such that said first and second conductive strips on said first sheet are orthogonal to said first and second conductive strips on said second sheet and such that the resistive material on said first sheet faces the resistive material on said second sheet but is separated therefrom by a selected space. - View Dependent Claims (2, 3, 4)
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Specification