Clustered scan method of capacitive touch device
A clustered scan method of a capacitive touch device is disclosed. According to the method, n drive lines of the capacitive touch device are divided into multiple clusters. Each of the clusters has a same number of drive lines. The clusters are driven by a clustered scan procedure in sequence. In each clustered scan procedure, the drive lines of the present cluster are driven for b times, wherein b is equal to the number of the drive lines of each cluster. If at least one bordering drive line exists, a bordering clustered scan procedure is executed, and a bordering drive line and some of drive lines of the previous clusters are driven.
1. A clustered scan method of a capacitive touch device having n drive lines X 1 to Xn and a sense line, wherein the n drive lines are divided into C clusters and k bordering drive lines, each cluster has b driving lines, and C, b, and k are positive integers, and the clustered scan method comprising:
(s1) sequentially driving each of the C clusters to obtain sensed values of sense points crossed by the drive lines of the cluster and the sense line; wherein when driving each of the C clusters, b drive lines of the cluster are driven simultaneously; and
(s2) executing a scanning process for driving the bordering drive lines, wherein the scanning process comprises:
(a) simultaneously driving b drive lines including the n th drive line k times by using k combinations of driving signals to obtain sensed values A n , A n−1 , . . . , A n−k+1 of the sense line; and
(b) determining the sensed values of sense points crossed by the drive lines from the n th drive line to the (n−k+1) th drive line and the sense line according to the sensed values A n , A n−1 , . . . , A n−k+1 of the sense line;
wherein in the step (b), the sensed values of the sense points crossed by the drive lines from the n th drive line to the (n−k+1) th drive line and the sense line are obtained based on the sensed values of the sense points crossed by the drive lines from the (n−k) th drive line to the (n−b+1) th drive line and the sense line.
2. The clustered scan method as claimed in claim 1 , wherein the sensed values, A n , A n−1 , . . . , A n−k+1 in step (a) are represented by sensing equations respectively, and the clustered scan method further comprises:
predetermining whether the sensing equations corresponding to the k combinations of driving signals have no solutions, when the sensing simultaneous equations have no solutions, modifying the k combinations of the driving signals and then executing the step (a).
3. The clustered scan method as claimed in claim 2 , wherein in the step (b), the sensed values of the sense points crossed by the drive lines from the n th drive line to the (n−k+1) th drive line and the sense line are obtained based on the sensed values of the sense points crossed by the drive lines from the (n−k) th drive line to the (n−b+1) th drive line and the sense line.
4. The clustered scan method as claimed in claim 1 , wherein each of the combinations of the driving signals comprises b driving signals, and each driving signal is a positive driving signal, zero, or a negative driving signal.
5. The clustered scan method as claimed in claim 3 , wherein each of the combinations of the driving signals comprises b driving signals, and each driving signal is a positive driving signal, zero, or a negative driving signal.
6. The clustered scan method as claimed in claim 4 , wherein b is a positive integer between 3 and (n−1).
7. The clustered scan method as claimed in claim 5 , wherein b is a positive integer between 3 and (n−1).
8. The clustered scan method as claimed in claim 6 , wherein the sensed values A n , A n−1 , . . . , A n−k+1 , are digital values converted from analog values obtained by sensing the sensing line.
9. The clustered scan method as claimed in claim 7 , wherein the sensed values A n , A n−1 , . . . , A n−k+1 , are digital values converted from analog values obtained by sensing the sensing line.
10. The clustered scan method as claimed in claim 8 , wherein the driving signals for driving different drive lines have a same frequency.
11. The clustered scan method as claimed in claim 9 , wherein the driving signals for driving different drive lines have a same frequency.
12. The clustered scan method as claimed in claim 10 , wherein the different clusters respectively correspond to different drive lines.
13. The clustered scan method as claimed in claim 11 , wherein the different clusters respectively correspond to different drive lines.
14. The clustered scan method as claimed in claim 12 , wherein the positive signal and the negative signal are generated by phase shifting.
15. The clustered scan method as claimed in claim 13 , wherein the positive signal and the negative signal are generated by phase shifting.
16. The clustered scan method as claimed in claim 1 , wherein the k bordering drive lines are determined by whether a reminder k exists, and the reminder k is obtained by dividing n by b.