Touch screen system

• US 9,046,973 B2
• Filed: 06/01/2012
• Issued: 06/02/2015
• Est. Priority Date: 06/01/2011
• Status: Expired due to Fees

• Current Assignee: Scriptel Corporation
• Original Assignee: Scriptel Corporation
• Inventors: Powers, Winston J.
• Primary Examiner(s): Mangistu, Amare
• Assistant Examiner(s): ZUBAJLO, JENNIFER L
• Application Number:
  US13/487,095
• Publication Number:
  US 20120306792A1
• Time in Patent Office: 1,096 Days
• Field of Search: 345/173, 345/174, 345/175
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A touch screen system has an electrically non-conductive substrate. At least one electrically conductive pad is disposed upon the substrate, and an electrically non-conductive cover is placed over the pad. The system further includes a controller having a touch switch interface and at least one output, the touch switch interface being electrically coupled to the pad. The controller generates an AC signal, the AC signal being electrically coupled from the controller to the pad through the touch switch interface, thereby generating an electrostatic field proximate the pad. The controller is also configured to detect at the touch switch interface a change in the electrostatic field resulting from an actuating member contacting the cover proximate the pad. The controller provides at the output a signal relating to the change in the electrostatic field.

Claims

1. A touch screen system, comprising:

a single electrically non-conductive substrate having a first side and a second, opposing side;

at least one electrically conductive pad disposed upon each of the first and second sides of the substrate and oriented generally orthogonally with respect to one another; and

a controller having a touch switch interface and at least one output, the touch switch interface being electrically coupled to the pads,

the controller generating an AC signal, the AC signal being electrically coupled from the controller to the pads through the touch switch interface, thereby generating an electrostatic field proximate the pads,

the controller being configured to detect at the touch switch interface a change in the electrostatic field resulting from an actuating member placed in proximity to at least one of the pads, and

the controller further including a memory configured to store a predetermined set of instructions, the set of instructions including a function to increase the signal-to-noise ratio of the touch screen system, the function being configured to measure the signal-to-noise ratio of a predetermined spectrum for the AC signal, select a frequency within the spectrum having a high signal-to-noise ratio, and set the frequency of the AC signal to the select frequency,

the controller providing at the output a signal relating to the change in the electrostatic field.

2. The touch screen system of claim 1 wherein the substrate is made from polyethylene terephthalate.

3. The touch screen system of claim 1 wherein the pads are made from at least one of indium tin oxide, graphene, gold, silver, carbon, electrically-conductive inks, conductive oxides and nano-metal particles.

4. The touch screen system of claim 3 wherein the pads are generally transparent.

5. The touch screen system of claim 1, further including an electrically non-conductive cover over at least a portion of the pads.

6. The touch screen system of claim 1, further comprising a plurality of electrically conductive pads disposed upon each of the first and second sides of the substrate, the pads being arranged in predetermined rows and columns and oriented generally orthogonally with respect to one another.

7. The touch screen system of claim 1 wherein the signal provided at the output of the controller relates to a set of X-Y coordinate points.

8. The touch screen system of claim 1 wherein the pads include at least one of a square, rectangular, round, triangular, wedge-shaped, or a polygonal shape.

9. The touch screen system of claim 1 wherein the controller further includes at least one of a computer, microcontroller or microprocessor configured to execute the instructions.

10. The touch screen system of claim 1 wherein the instructions include a function to control the amplitude of the AC signal, the function being configured to:

monitor for a touch-actuation;

when a touch-actuation is detected, check that the amplitude of the AC signal is sufficient for accurate touch detection; and

if the amplitude of the AC signal is not sufficient for accurate touch detection, increase the amplitude of the AC signal.

11. The touch screen system of claim 1 wherein the pads form a plurality of touch switches and the instructions include a function to alter the resolution of the touch screen system, the function being configured to:

monitor for actuation of at least one touch switch;

when a touch switch actuation is detected, measure and compare the signal levels of each of the plurality of touch switches; and

generate a map relating to an active area comprising actuated touch switches to determine the location of the touch actuation.

12. The touch screen system of claim 1 wherein the pads comprise:

a continuous matrix of channels disposed in the substrate; and

a predetermined quantity of graphene material disposed in the channels.

13. The touch screen system of claim 1 wherein the pads comprise:

a plurality of channels disposed in the substrate;

a predetermined quantity of graphene material disposed in the channels; and

at least one trace electrically connecting together the graphene in the channels.

14. A touch screen system, comprising:

a single electrically non-conductive substrate made from polyethylene terephthalate, the substrate having a first side and a second, opposing side;

at least one electrically conductive, generally transparent pad disposed upon each of the first and second sides of the substrate and oriented generally orthogonally with respect to one another;

an electrically non-conductive cover placed over at least a portion of the pads; and

a controller having a touch switch interface and at least one output, the touch switch interface being electrically coupled to the pads,

the controller generating an AC signal, the AC signal being electrically coupled from the controller to the pads through the touch switch interface, thereby generating an electrostatic field proximate the pads,

the controller being configured to detect at the touch switch interface a change in the electrostatic field resulting from an actuating member placed in proximity to at least one of the pads, and

the controller further including a memory configured to store a predetermined set of instructions, the set of instructions including a function to increase the signal-to-noise ratio of the touch screen system, the function being configured to measure the signal-to-noise ratio of a predetermined spectrum for the AC signal, select a frequency within the spectrum having a high signal-to-noise ratio, and set the frequency of the AC signal to the select frequency,

the controller providing at the output a signal relating to the change in the electrostatic field.

15. The touch screen system of claim 14, further comprising a plurality of electrically conductive pads disposed upon each of the first and second sides of the substrate, the pads being arranged in predetermined rows and columns and oriented generally orthogonally with respect to one another.

16. The touch screen system of claim 14 wherein the signal provided at the output of the controller relates to a set of X-Y coordinate points.

17. The touch screen system of claim 14 wherein the pads include at least one of a square, rectangular, round, triangular, wedge-shaped, or a polygonal shape.

18. A method for providing a touch screen system, comprising the steps of:

selecting a single electrically non-conductive substrate having a first and a second, opposing side;

disposing at least one electrically conductive pad upon each of the first and second sides of the substrate and orienting the pads generally orthogonally with respect to one another; and

providing a controller having a touch switch interface and at least one output, the touch switch interface being electrically coupled to the pads,

the controller generating an AC signal, the AC signal being electrically coupled from the controller to the pads through the touch switch interface, thereby generating an electrostatic field proximate the pads,

the controller being configured to detect at the touch switch interface a change in the electrostatic field resulting from an actuating member placed in proximity to at least one of the pads, and

the controller further including a memory configured to store a predetermined set of instructions, the set of instructions including a function to increase the signal-to-noise ratio of the touch screen system, the function being configured to measure the signal-to-noise ratio of a predetermined spectrum for the AC signal, select a frequency within the spectrum having a high signal-to-noise ratio, and set the frequency of the AC signal to the select frequency,

the controller providing at the output a signal relating to the change in the electrostatic field.