Detecting Method for Touch Panel

• US 20100079397A1
• Filed: 09/29/2009
• Published: 04/01/2010
• Est. Priority Date: 09/30/2008
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: AU Optronics Corporation
• Inventors: Yang, Chun-Wei, Hsu, Yu-Min
• Granted Patent: US 8,436,262 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184

Abstract

This invention provides a detecting method for a touch panel, comprising providing a sensing matrix having a plurality of sensing units, detecting sensing data generated from the sensing unit and defining the sensing unit as a touch point or a non-touch point based on the sensing data and group at least a portion of the touch points to form a touch point group. In the same touch point group, projection of a touch point overlaps a projection of at least one touch point of the touch point group in one of a row direction and a column direction while adjacent to a projection in the other direction of at least one touch point of the touch point group. Afterward, extreme positions of the touch point group in the row direction and the column direction is retrieved. Lastly, the detecting method includes determining a touch center position based on the extreme positions in the row direction and the column direction.

Claims

1. A detecting method for a touch panel, comprising:

providing a sensing matrix having a plurality of sensing units;

detecting a sensing data generated from the sensing unit and defining the sensing unit as a touch point or as a non-touch point based on the sensing data;

grouping at least a portion of the touch points to form a touch point group, wherein a projection of the touch point in the touch point group is overlapping a projection of at least one touch point of the touch point group in one of a row direction or a column direction and is adjacent to a projection of at least one touch point of the touch point group in the other direction;

retrieving extreme positions of the touch point group in the row direction and the column direction; and

determining a touch center position based on the extreme positions in the row direction and the column direction.

2. The detecting method of claim 1, wherein the step of defining the sensing unit includes:

dividing the sensing matrix into a plurality of parallel sensing arrays having the sensing units; and

scanning sequentially the sensing data generated from the sensing units of each sensing array and defining the sensing unit as a touch point or a non-touch point based on the sensing data.

3. The detecting method of claim 2, wherein the step of retrieving extreme positions includes:

recording and comparing positions of the touch points of the touch point group first and last detected at each of the sensing arrays to determine the extreme positions of the touch point group in the row direction;

acquiring the sensing array first having the touch point detected to determine the extreme position of the touch point group in the column direction; and

acquiring the sensing array having non of the touch points included in the touch point group to determine the extreme position of the touch point group in the column direction.

4. The detecting method of claim 2, wherein the step of retrieving the extreme positions includes:

recording sequentially the positions of the touch points of the sensing array in the row direction in a plurality of first memory units of a first memory group, wherein each of the first memory units corresponds to one of the sensing units in the sensing arrays;

recording sequentially the positions of the touch points of the next sensing array in the row direction in the first memory units of the first memory group;

grouping the adjacent touch points with positions recorded in the first memory group into the touch point group;

determining the extreme positions in the row direction based on positions recorded in the first memory units.

5. The detecting method of claim 4, wherein the step of retrieving the extreme positions includes:

recording an initial sensing array value in a plurality of second memory units of a second memory group, wherein the initial sensing array value occurs after detecting the first touch point of the touch point group in each of the sensing array;

acquiring a terminal sensing array value after scanning the sensing array not having the touch point of the touch point group; and

determining the extreme positions of the touch point group in the row direction based on the initial sensing array and the terminal sensing array value.

6. The detecting method of claim 1, wherein the step of determining the touch center position includes the following steps:

defining a touch region based on the extreme positions of the touch point group in the row direction and the column direction of the sensing matrix, wherein at least four touch points of the touch point group are adjacent to a periphery of the touch region, the touch region has at least four reference points located at the periphery of the touch region, the reference points correspond to the touch points adjacent to the touch region, the touch region substantially covers the touch point group.

7. The detecting method of claim 6, wherein the reference points includes at least a first reference point, a second reference point, a third reference point and a fourth reference point, the step of determining the touch center position includes:

obtaining a row center coordinate based on positions of the first reference point and the second reference point;

obtaining a column center coordinate based on positions of the third reference point and the fourth reference point; and

determining the touch center position based on the row center coordinate and the column center coordinate.

8. The detecting method of claim 1, wherein the step of defining the sensing unit includes measuring the sensing data transmitted from the sensing unit in a first frame period and obtaining a first threshold value based on the sensing data.

9. The detecting method of claim 8, wherein the step of defining the sensing unit includes:

measuring the sensing data transmitted from the sensing units in a second frame period next to the first frame period; and

comparing the sensing data with the first threshold value to determine if the sensing unit is a touch point or a non-touch point.

10. The detecting method of claim 9, wherein the step of defining the sensing unit further includes generating a second threshold value based on the sensing data obtained in the second frame period.

11. The detecting method of claim 9, wherein the sensing matrix includes a first row and a second row, the first row and the second row respectively includes a plurality of the sensing units, the step of obtaining the first threshold value includes:

measuring the sensing data from the sensing units in the first row;

obtaining a first reference data based on the sensing data from the first row;

measuring the sensing data from the sensing units in the second row;

obtaining a second reference data based on the sensing data from the second row; and

obtaining the first threshold value based on the first reference data and the second reference data.

12. The detecting method of claim 8, wherein the first threshold value is an average value of the sensing data.

13. The detecting method of claim 1, including:

defining a sensing period and an output period; and

transmitting a touch center position signal in the output period based on the touch center position.

14. A touch detection method, including the following steps:

providing a sensing matrix having a plurality of sensing rows, wherein each of the sensing rows includes a plurality of sensing units;

defining the sensing unit as a touch point or a non-touch point based on a sensing data transmitted from the sensing unit;

grouping at least a portion of the touch points to form a touch point group, wherein a projection of the touch point in the touch point group is overlapping a projection in a row direction of at least one touch point of the touch point group and is adjacent to a projection in a column direction of at least one touch point of the touch point group;

detecting the touch points of the touch point group having the most touch points in one of the sensing rows and obtaining positions of the two touch points first and last detected in the sensing row;

obtaining the sensing rows having the touch point first detected and a sensing row first detected to have only non-touch points;

defining a touch region, wherein at least four of the touch points in the touch point group are adjacent to a periphery of the touch region, the touch region has at least four reference points located at the periphery of the touch region; and

determining a touch center position based on positions of the reference points.