METHOD AND TOUCH APPARATUS FOR CALIBRATING COORDINATE VALUE NEAR EDGE OF TOUCH PANEL

1 . A method for calibrating a coordinate value near an edge of a touch panel, comprising:

obtaining a calculated coordinate according to a capacitance change corresponding to a proximity event;

selecting a first linear function from a plurality of first linear functions comprised in a look-up table (LUT) according to the calculated coordinate and the capacitance change; and

obtaining a calibrated coordinate according to the first linear function and the calculated coordinate.

2 . The method according to claim 1 , wherein the calculated coordinate and the calibrated coordinate correspond to an axial direction of the touch panel, and the touch panel comprises a plurality of sensing electrode units arranged along the axial direction for sensing a plurality of capacitance changes of the touch panel.

3 . The method according to claim 1 , the step of selecting the first linear function from the LUT further comprises:

obtaining a square root of a total capacitance change according to the calculated coordinate and the capacitance change;

wherein, the LUT comprises slopes and starting points of the first linear functions corresponding to square roots of a plurality of total capacitance changes.

4 . The method according to claim 3 , wherein the LUT further comprises slopes and starting points of a plurality of second linear functions, and the step of obtaining the square root of the total capacitance change comprises:

selecting a second linear function from the second linear functions comprised in the LUT according to the calculated coordinate and a projection area, wherein the projection area is associated with the capacitance change of the touch panel; and

obtaining the square root of the total capacitance change according to the second linear function and the calculated coordinate.

5 . The method according to claim 4 , wherein intervals of the calculated coordinates corresponding to the first linear functions corresponding to the square root of the same capacitance change are different.

6 . The method according to claim 4 , wherein intervals of the calculated coordinates corresponding to the first linear functions corresponding to the same projection area are different.

7 . A touch apparatus adapted to calibrate a coordinate value of a touch panel, comprising:

a memory module, comprising a look-up table (LUT); and

a processing module, coupled to the memory module to perform steps of:

obtaining a calculated coordinate according to a capacitance change corresponding to a proximity event;

selecting a first linear functions from the first linear functions comprised in the LUT according to the calculated coordinate and the capacitance change; and

obtaining a calibrated coordinate according to the first linear function and the calculated coordinate.

8 . The touch apparatus according to claim 7 , wherein the calculated coordinate and the calibrated coordinate correspond to an axial direction of the touch panel, and the touch panel comprises a plurality of sensing electrode units arranged along the axial direction for sensing a plurality of capacitance changes of the touch panel.

9 . The touch apparatus according to claim 7 , wherein the step of selecting the first linear function from the LUT further comprises:

obtaining a square root of a total capacitance change according to the calculated coordinate and the capacitance change;

wherein, the LUT comprises slopes and starting points of the first linear functions corresponding to square roots of a plurality of total capacitance changes.

10 . The touch apparatus according to claim 9 , wherein the LUT further comprises a plurality of second linear functions, and the step of obtaining the square root of the total capacitance comprises:

selecting a second linear function from the second linear functions comprised in the LUT according to the calculated coordinate and a projection area, wherein the projection area is associated with the capacitance change of the touch panel; and

obtaining the square root of the total capacitance change according to the second linear function and the calculated coordinate.

11 . The touch apparatus according to claim 10 , wherein intervals of the calculated coordinates corresponding to the first linear functions corresponding to the square root of the same capacitance change are different.

12 . The touch apparatus according to claim 10 , wherein intervals of the calculated coordinates corresponding to the first linear functions corresponding to the same projection area are different.