METHOD TO IMPROVE PERFORMANCE OF A PROPORTIONAL AREA WEIGHTED SENSOR FOR TWO-DIMENSIONAL LOCATIONS ON A TOUCH SCREEN

• US 20120127131A1
• Filed: 12/22/2010
• Published: 05/24/2012
• Est. Priority Date: 11/22/2010
• Status: Active Grant

• Current Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Original Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Inventors: Jung, David Hann, Nolting, John
• Granted Patent: US 8,400,431 B2
• Time in Patent Office: Days
• US Class Current: 345/178
• 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
• CPC Class Codes: G06F 3/0448 Details of the electrode shape, e.g. for enhancing the detection of touches, for generating specific electric field shapes, for enhancing display quality

Abstract

An electronic appliance including a processor and a computer-readable medium, having instructions for execution by a processor is provided. The instructions causing the processor to perform methods to obtain an error map for locations in a touch sensor. The method including inputting a geometry for a touch sensor layout; inputting coordinates for centroids of sensing elements in the touch sensor layout; and inputting a touch geometry. The method includes the steps of selecting a plurality of test points on the touch sensor layout; generating, a calculated touch location for each of the plurality of test points; and an error map from the calculated touch locations and the test points. The method may include generating an error measure from the error map; displaying, the generated error map and the generated error measure; and adjusting the geometry for the touch sensor layout if the error measure is larger than a tolerance value.

Claims

1. An electronic appliance including a processor, a computer-readable medium, an input device, and a display device, the computer-readable medium including instructions for execution by a processor, the instructions when executed causing the processor to perform a method to obtain an error map for locations in a touch sensor, the method comprising:

inputting, using the input device of the electronic appliance, a geometry for a touch sensor layout;

inputting, using the input device of the electronic appliance, coordinates for a centroid of sensing elements in the touch sensor layout;

inputting, using the input device of the electronic appliance, a touch geometry;

selecting, using the input device of the electronic appliance, a plurality of test points on the touch sensor layout;

generating, by the processor of the electronic appliance, a calculated touch location for each of the plurality of test points;

generating, by the processor of the electronic appliance, an error map from the calculated touch locations and the test points;

generating, by the processor of the electronic appliance, an error measure from the error map;

displaying, on a display device coupled to the electronic appliance, the generated error map and the generated error measure; and

adjusting, using the input device of the electronic appliance, the geometry for the touch sensor layout if the error measure is larger than a tolerance value.

2. The method of claim 1, wherein inputting the geometry for the touch sensor layout comprises inputting a geometry including sensing elements having interlaced, non-overlapping shapes, and each sensing element having a centroid.

3. The method of claim 2, wherein adjusting the geometry for the touch sensor layout comprises:

modifying a shape of at least one of the sensing elements.

4. The method of claim 2, wherein adjusting the geometry for the touch sensor layout comprises:

modifying a location of the centroid of at least one of the sensing elements.

5. The method of claim 3, wherein modifying a shape of at least one of the sensing elements comprises modifying the shape of at least one adjacent sensing element so that a gap between the at least one sensing element and the adjacent sensing element remains nearly constant.

6. The method of claim 1, wherein generating a calculated touch location for each of the plurality of test points comprises:

obtaining overlap proportions from the touch geometry and a plurality of sensing elements in the touch sensor layout on at least one of the test points on the touch sensor layout;

determining a first two-dimensional touch location by an average of the centroid locations of the plurality of sensing elements weighted by the obtained overlap proportions;

determining complementary factors using the determined first two-dimensional touch location;

obtaining a second two-dimensional touch location by an average of locations of each of a plurality of sensing elements weighted by the overlap proportions and the complementary factors.

7. The method of claim 1, wherein generating an error map from the calculated touch locations and the test points comprises:

plotting coordinates of the test points on a two-dimensional frame; and

plotting a two dimensional error vector anchored at each of the test points plotted on the two-dimensional frame.

8. The method of claim 1, wherein generating an error map from the calculated touch locations and the test points comprises:

plotting the magnitude of the two dimensional error vectors as a contour map which may be color coded or gradient shaded according to the magnitude of the error.

9. The method of claim 7, wherein the two dimensional error vector anchored at each of the test points is obtained by determining a difference between the calculated touch location and the test point.

10. The method of claim 1, wherein selecting a plurality of test points on the touch sensor layout comprises selecting a grid of points on the touch sensor layout, each point separated from its nearest neighbor by a predetermined finite distance.

11. The method of claim 1, wherein selecting a plurality of test points on the touch sensor layout comprises selecting a one-dimensional test trajectory on the touch sensor layout.

12. The method of claim 11, wherein the step of generating an error map from the calculated touch locations and the test points comprises plotting a trajectory of calculated locations next to a plot of the one-dimensional test trajectory.

13. The method of claim 11, wherein the one-dimensional test trajectory comprises a plurality of lines parallel to an axis in a two-dimensional frame.

14. The method of claim 11, wherein the one-dimensional test trajectory comprises a plurality of lines parallel to at least two orthogonal axes in a two-dimensional frame.

15. The method of claim 1 wherein generating, by the processor of the electronic appliance, an error measure from the error map comprises the use of a histogram obtained from the magnitude of the distances between the calculated touch locations and the test points in the error map.