TOUCH PANEL SYSTEM AND METHOD FOR DISTINGUISHING MULTIPLE TOUCH INPUTS

• US 20060139340A1
• Filed: 02/08/2006
• Published: 06/29/2006
• Est. Priority Date: 10/03/2001
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Geaghan, Bernard O.
• Application Number:
  US11/275,976
• Publication Number:
  US 20060139340A1
• Time in Patent Office: Days
• US Class Current: 345/177
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures

Abstract

Touch panel systems and methods are disclosed that can distinguish temporally overlapping touch inputs from single touch inputs so that valid touch position coordinates can be determined. Touch panel systems and methods of the present invention can distinguish overlapping touches by comparing signal magnitudes to specified thresholds, by comparing the rates of change of signal magnitudes or measured positions to determined parameters, by locating the proximity a calculated location to icons or other such active areas, and the like. Because touch panel systems and methods of the present invention can discriminate single touches from double touches, they can be used in multiple user applications such as multiplayer games as well as in applications that may be subject to rapidly successive or overlapping touch inputs.

Claims

1. A method for identifying positions of temporally overlapping touch inputs on a touch panel surface in a touch screen system, the touch panel surface having an X dimension and a Y dimension, the method comprising the steps of:

(a) sequentially measuring signals indicative of the touch input positions, the touch input positions having X and Y coordinates in the X and Y dimensions, and the signals having associated X and Y characteristics;

(b) for each measured signal indicative of the touch input positions, storing at least one of the associated X characteristics;

(c) for each measured signal indicative of the touch input positions, storing at least one of the associated Y characteristics;

(d) for possible matching of X and Y coordinates, comparing at least one of the stored X characteristics with a corresponding stored Y characteristic; and

(e) selecting X and Y coordinate matches corresponding to actual touch input positions based on the comparison of step (d).

2. The method of claim 1, wherein the X and Y characteristics comprise signal magnitude.

3. The method of claim 2, wherein the signal magnitude is a signal width.

4. The method of claim 2, wherein the signal magnitude is a signal depth.

5. The method of claim 1, wherein the X and Y characteristics comprise signal rate of change.

6. A touch screen system, comprising:

a touch panel having a touch surface, the touch surface having an X dimension and a Y dimension; and

a processing unit for determining positions of temporally overlapping touch inputs on said touch surface, said processing unit configured to;

sequentially measure signals indicative of touch input positions, said touch input positions having X and Y coordinates in the X and Y dimensions, and said touch input signals having associated X and Y characteristics;

store at least one of said associated X characteristics and at least one of said associated Y characteristics;

compare at least one of said stored X characteristics with a corresponding stored Y characteristic; and

select X and Y coordinate matches corresponding to actual touch input positions based on the comparison between at least one of stored X characteristics and said corresponding Y characteristic.

7. The touch screen system of claim 6, wherein said X and Y characteristics comprise signal magnitude.

8. The touch screen system of claim 7, wherein said signal magnitude is a signal width.

9. The touch screen system of claim 7, wherein said signal magnitude is a signal depth.

10. The touch screen system of claim 6, wherein the X and Y characteristics comprise signal rate of change.

11. A system comprising:

a touch panel input device with a touch surface having an X dimension and a Y dimension;

a signal detector operating for a succession of time intervals to detect an X signal and a Y signal corresponding to touch point inputs on said touch surface, said X signal and said Y signal indicative of actual touch point positions on the touch surface and having associated X and Y characteristics, wherein more than on X signal and more than one Y signal are detected during a single time interval; and

a processing unit adapted to select matching coordinates in said X and Y dimensions corresponding to actual touch point positions of temporally overlapping touch point inputs, wherein the processing unit selects the coordinate matches based on a correlation value between said associated X and Y characteristics.

12. The system of claim 11, wherein said X and Y characteristics comprise signal magnitude.

13. The system of claim 12, wherein said signal detector comprises a reflector array that acts upon acoustic waves propagating along the touch panel input device and reflects waves at sides of the touch panel input device and a receiver for detecting the reflected waves, and wherein said magnitudes correspond to amplitudes of the reflected waves and said coordinates correspond to times at which the reflected waves are detected.

14. The system of claim 12, wherein said signal magnitude is a signal width.

15. The system of claim 12, wherein said signal magnitude is a signal depth.

16. The touch screen system of claim 12, wherein the X and Y characteristics comprise signal rate of change.