| 主权项 |
1. A coordinate detecting device comprising:
a plurality of electrodes arranged in a predetermined direction; a detecting unit configured to detect the capacitance of each of the plurality of electrodes; and an arithmetic processing unit configured to calculate the coordinates of a detection target using different calculation methods according to the state of a variation in the capacitance of the plurality of electrodes, wherein the arithmetic processing unit calculates the coordinates of the detection target, using a centroid calculation method of calculating the coordinates of the centroid when a first touch condition is detected, and using a curve approximation method of calculating a peak of a curve when a second touch condition is detected, wherein a touch area under the first touch condition is larger than a touch area under the second touch condition, wherein the arithmetic processing unit switches from one of the centroid calculation method and the curve approximation method to the other of the centroid calculation method and the curve approximation method according to the conditions in relation to the touch areas, wherein the arithmetic processing unit determines a region to be a first recognition region when the region includes electrodes with a capacitance variation equal to or greater than a first threshold value successive from the peak electrode and determines a region to be a second recognition region when the region includes electrodes with a capacitance variation equal to or greater than a second threshold value successive from the peak electrode, wherein when an absolute value of the difference between the capacitance variation of the peak electrode and the capacitance variation of the electrode which is not adjacent to the peak electrode in the first recognition region is equal to or less than a predetermined value, the arithmetic processing unit applies the centroid calculation method to the electrodes in the first recognition region, thereby calculating the coordinates of the detection target, and when the absolute value of the difference between the capacitance variation of the peak electrode and the capacitance variation of the electrode which is not adjacent to the peak electrode is greater than the predetermined value, the arithmetic processing unit applies the curve approximation method to at least the peak electrode and an electrode adjacent to the peak electrode in the second recognition region, thereby calculating the coordinates of the detection target. |
