Method for detecting multiple touch positions on a touch panel

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

periodically scanning the touch panel;

detecting a possible touch position at a first time during scanning the touch panel;

determining the detected possible touch position as a first actual touch position and recording coordinate values of the first actual touch position on a first dimensional direction and a second dimensional direction;

scanning the touch panel after the first time;

detecting a plurality of new possible touch positions at a second time after the first time; and

comparing coordinate values of the detected new possible touch positions with the coordinate values of the first actual touch position on the first dimensional direction and the second dimensional direction to thereby determine a second actual touch position from the new possible touch positions, comprising:

comparing the coordinate values of the detected new possible touch positions with the coordinate value of the first actual touch position on the first dimensional direction;

comparing the coordinate values of the detected new possible touch positions with the coordinate value of the first actual touch position on the second dimensional direction;

removing some of the new possible touch positions having a coordinate value on the first dimensional direction same as that of the first actual touch position;

removing some of the new possible touch positions having a coordinate value on the second dimensional direction same as that of the first actual touch position; and

determining the remainder of the new possible touch positions as the second actual touch position.

2. The method as claimed in claim 1 , further comprising:

scanning the touch panel after the second time; and

when the detected new possible touch positions are decreased, confirming the coordinate values of the first and second actual touch positions on the first and second dimensional directions according to coordinate values of disappeared possible touch positions of the new possible touch positions on the first and second dimensional directions,

wherein the step of confirming the coordinate values of the first and second actual touch positions on the first and second dimensional directions according to coordinate values of disappeared possible touch positions of the new possible touch positions on the first and second dimensional directions comprises:

acquiring coordinate values of the respective disappeared possible touch positions on the first and second dimensional directions;

acquiring the coordinate value of a first possible touch position of the disappeared possible touch positions on the first dimensional direction and the coordinate value of a second possible touch position of the disappeared possible touch positions on the second dimensional direction, and using the coordinate value of the first possible touch position on the first dimensional direction and the coordinate value of the second possible touch position on the second dimensional direction respectively to confirm the coordinate values of the first actual touch position on the first and second dimensional directions; and

acquiring the coordinate value of the first possible touch position on the second dimensional direction and the coordinate value of the second possible touch position on the first dimensional direction, and using the coordinate value of the second possible touch position on the first dimensional direction and the coordinate value of the first possible touch position on the second dimensional direction respectively to confirm the coordinate values of the second actual touch position on the first and second dimensional directions.

3. A method for detecting multiple touch positions on a touch panel, comprising:

periodically scanning the touch panel; and

determining a new possible touch position by comparing coordinate values of at least one new possible touch position on a first dimensional position and a second dimensional position caused by the new actual touch position on the touch panel with coordinate values of at least one current actual touch position on the first and second dimensional directions detected before the generation of the new actual touch position, comprising:

when the at least one current actual touch position is not existed before the generation of the new actual touch position:

recording the coordinate values of the at least one new possible touch position on the first and second dimensional directions as the coordinate values of the new actual touch position on the first and the second dimensional directions; and

recording the coordinate values of the new actual touch position on the first and second dimensional directions as coordinate values of one current actual touch position on the first and second dimensional directions; and

when the at least one current actual touch position is existed before the generation of the new actual touch position:

detecting a plurality of the new possible touch positions resulting from the generation of the new actual touch position, comparing the coordinate values of the detected new possible touch positions with the coordinate values of the at least one current actual touch position on the first and second dimensional directions and determining the coordinate values of the new actual touch position from the new possible touch positions on the first and second dimensional directions; and

recording the coordinate values of the new actual touch position on the first and second dimensional directions as coordinate values of one current actual touch position on the first and second dimensional directions.

4. The method as claimed in claim 3 , wherein the step of detecting a plurality of the new possible touch positions resulting from the generation of the new actual touch position, comparing the coordinate values of the detected new possible touch positions with the coordinate values of the at least one current actual touch position on the first and second dimensional directions and determining the coordinate values of the new actual touch position from the new possible touch positions on the first and second dimensional directions comprises:

comparing the coordinate values of the detected new possible touch positions with the coordinate values of the at least one current actual touch position on the first and second dimensional directions;

acquiring a particular touch position from the new possible touch positions, wherein a coordinate value of the particular touch position on the first dimensional direction is different from that of the at least one current actual touch position on the first dimensional direction, a coordinate value of the particular touch position on the second dimensional direction is different from that of the at least one current actual touch position on the second dimensional direction; and

determining the particular touch position as the new actual touch position.

5. A method for detecting multiple touch positions on a touch panel, comprising:

periodically scanning the touch panel;

detecting a decreased status of a plurality of possible touch positions to acquire disappeared possible touch positions from the plurality of possible touch positions, wherein the plurality of possible touch positions comprises a plurality of actual touch positions and a plurality of virtual touch positions resulting from an inherent characteristic of the touch panel;

comparing coordinate values of the disappeared possible touch positions on a first dimensional direction and a second dimensional direction with one another to thereby determine one of the disappeared possible touch positions which has a coordinate value on the first dimensional direction same as that of at least one of the other disappeared possible touch positions and has a coordinate value on the second dimensional direction same as of at least one of the other disappeared possible touch positions as one of the actual touch positions.

6. The method as claimed in claim 5 , further comprising:

determining one of the plurality of possible touch positions which is not included in the disappeared possible touch positions as another one of the actual touch positions.