Resistive touch screen incorporating conductive polymer
First Claim
Patent Images
1. A resistive touch screen transmissive of visible light comprising:
- a top sheet movable toward a bottom substrate under the influence of a touch input, the top sheet comprising a first conductive polymer layer facing a second conductive polymer layer disposed on the bottom substrate, the touch screen configured for electronic coupling to controller electronics that use signals generated when the first and second conductive polymer layers make local contact to determine the position of local contact.
1 Assignment
0 Petitions
Accused Products
Abstract
Conductive polymers can be used as the signal carrying layers in resistive touch screens. Using conductive polymers can allow higher sheet resistance than is conventionally obtained using indium tin oxide while maintaining electrical continuity and durability of the layer. Higher sheet resistance can also lead to reduced errors and reduced power consumption, as well as better optical transmission. Sheet resistance may be limited on an upper end by desired data sampling rates. Also disclosed are resistive touch screens that employ a conductive polymer on both the topsheet and bottom substrate and that can be operated with the use of conventional electronics.
75 Citations
18 Claims
-
1. A resistive touch screen transmissive of visible light comprising:
a top sheet movable toward a bottom substrate under the influence of a touch input, the top sheet comprising a first conductive polymer layer facing a second conductive polymer layer disposed on the bottom substrate, the touch screen configured for electronic coupling to controller electronics that use signals generated when the first and second conductive polymer layers make local contact to determine the position of local contact. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
-
15. A resistive touch screen system comprising:
-
a top sheet movable toward a bottom substrate under the influence of a touch input, the top sheet comprising a first resistive layer facing a second resistive layer disposed on the bottom substrate, at least one of the first and second resistive layers comprising a conductive polymer; and
controller electronics electronically coupled to the first and second resistive layers, the controller electronics configured to use signals generated when the first and second resistive layers make local contact to determine the position of local contact, wherein the touch screen systems yields 100,000 or more touch inputs in the same location before failure of the device when the controller electronics are operated at about 3 to 5 volts. - View Dependent Claims (16)
-
-
17. A method of making a touch sensor comprising a resistive layer disposed on a substrate comprising:
-
selecting a desired minimum sampling rate for the touch sensor;
selecting a touch sensor construction and dimensions for the resistive layer;
determining the RC constant of the resistive layer given the selected dimensions;
determining a maximum sheet resistance for the resistive layer based on the determined RC constant; and
coating a conductive polymer material on the substrate to form the resistive layer at a thickness that gives a sheet resistance that does not exceed the maximum sheet resistance. - View Dependent Claims (18)
-
Specification