Method for simulating a touch on a touch screen

• US 7,639,238 B2
• Filed: 10/04/2005
• Issued: 12/29/2009
• Est. Priority Date: 11/30/2001
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Hauck, Karl P.
• Primary Examiner(s): Dharia; Prabodh M
• Application Number:
  US11/242,972
• Publication Number:
  US 20060202969A1
• Time in Patent Office: 1,547 Days
• Field of Search: 345156-158, 345/162, 345/184, 345173-179, 345/443, 178/19, 178/20, 178 1801- 1807, 340/712, 341/22, 341/20
• US Class Current: 345/173
• CPC Class Codes: G06F 3/04186 Touch location disambiguation

Abstract

Methods are provided for simulating a touch on a touch screen by applying a first signal to a first surface of the touch screen, applying a second signal to a second, opposing surface of the touch screen sensor, and changing the first signal relative to the second signal. Such methods can be used to simulate a touch to the center of the touch screen, for example. The simulated touch can be used in some embodiments to perform diagnostics and/or calibrations functions.

Claims

1. A method of simulating a touch on a touch screen sensor having a top surface and a bottom surface, the top surface including a resistive layer configured to detect touch inputs and the bottom surface including a conductive layer, the method comprising:

applying a first signal to the resistive layer of the top surface;

applying a second signal to the conductive layer of the bottom surface; and

in the absence of a touch input to the touch screen, changing the first signal relative to the second signal to produce a simulated touch at an expected location on the touch screen sensor.

2. The method of claim 1, wherein the first and second signals comprise AC voltage signals.

3. The method of claim 1, wherein the expected location is at the touch screen center.

4. The method of claim 1, further comprising calculating an observed position for the simulated touch.

5. The method of claim 4, further comprising comparing the observed position with the expected location to develop an error value.

6. The method of claim 5, further comprising using the error value to perform a diagnostics function.

7. The method of claim 5, further comprising using the error value to perform a calibration function.

8. The method of claim 1, wherein the conductive layer of the bottom surface is configured for shielding the resistive layer during normal touch input detection operations.

9. The method of claim 1, wherein the touch screen sensor is a capacitive touch screen sensor.

10. The method of claim 1, wherein the recited steps are performed automatically on a periodic basis.

11. The method of claim 1, wherein the recited steps are performed automatically on a scheduled basis.

12. The method of claim 1, wherein the recited steps are performed automatically on power-up of a computer system for which the touch screen sensor provides a user input interface.

13. The method of claim 1, wherein the recited steps are performed automatically after a period of user inactivity.

14. The method of claim 1, wherein the recited steps are performed automatically responsive to a detected threshold.

15. A method of simulating a touch on a touch screen sensor having a top surface and a bottom surface, the top surface including a resistive layer configured to detect touch inputs and the bottom surface including a conductive layer, the method comprising:

applying a first signal to the resistive layer of the top surface;

applying a second signal to the conductive layer of the bottom surface; and

in the absence of a touch input to the touch screen, changing the first signal relative to the second signal to produce a simulated touch at an expected location on the touch screen sensor, wherein the recited steps are performed automatically responsive to a detected threshold that is based on a temperature measurement.

16. A method of calibrating a touch screen sensor having a top surface and a bottom surface, the top surface including a resistive layer configured to detect touch inputs and the bottom surface including a conductive layer, the method comprising the steps of:

applying a first signal to the resistive layer of the top surface;

applying a second signal to the conductive layer of the bottom surface;

changing the first signal relative to the second signal to produce a simulated touch at an expected location on the touch screen sensor,

calculating an observed position for the simulated touch;

comparing the observed position with the expected location to determine an error; and

using the error value to calibrate the touch screen sensor.

17. The method of claim 16, wherein the steps are performed automatically in the absence of a touch input to the touch screen sensor.

18. The method of claim 17, wherein the steps are performed automatically on at least one of:

a periodic basis, on a scheduled basis, on power-up of a computer system for which the touch screen sensor provides a user input interface, after a period of user inactivity, and responsive to a detected threshold.

19. The method of claim 17, wherein the steps are performed automatically responsive to an ambient condition measured by a sensor.

20. The method of claim 19, wherein the ambient condition is a temperature.