Stylus detection system having touch object detecting mode and stylus detecting mode
A stylus detecting system includes a sense array including N number of first lines and M number of second lines crossing the N number of first lines; and a touch controller connected to the sense array and configured to: (i) in a touch object detecting mode, drive the N number of first lines as transmission (TX) lines with a finger sensing TX signal and measure reception (RX) signals on the M number of second lines as RX lines, and (ii) in a stylus detecting mode, measure a stylus TX signal transmitted by a stylus, on both the N number of first lines and the M number of second lines, using # number of multiple RX channels (#RX channels) to sense more than one line of the N number of first lines and the M number of second lines at the same time, such that a stylus scanning time is reduced as compared to using a single RX channel to scan all lines, thereby completing a stylus scan in fewer total scans.
1 . A stylus detecting system, comprising:
a sense array including N number of first lines and M number of second lines crossing the N number of first lines, wherein N and M are positive integers greater than 0; and
a touch controller connected to the sense array and configured to:
(i) in a touch object detecting mode, drive the N number of first lines as transmission (TX) lines with a finger sensing TX signal and measure reception (RX) signals on the M number of second lines as RX lines, and
(ii) in a stylus detecting mode, measure a stylus TX signal transmitted by a stylus, on both the N number of first lines and the M number of second lines, using # number of multiple RX channels (#RX channels), wherein # is a positive integer greater than 0, to sense more than one line of the N number of first lines and the M number of second lines at the same time, such that a stylus scanning time is reduced as compared to using a single RX channel to scan all lines, thereby completing a stylus scan in fewer total scans.
2 . The stylus detecting system according to claim 1 , wherein the touch controller is configured to:
(i) in the touch object detecting mode, sense the M number of second lines as RX lines using the #RX channels, such that a touch scanning time is reduced as compared to using a single RX channel to scan all lines, thereby completing a touch scan in fewer total scans.
3 . The stylus detecting system according to claim 1 , wherein the touch controller is configured to:
(ii) in the stylus detecting mode, transmit synchronization or timing data to cause the stylus to transmit the stylus TX signal.
4 . The stylus detecting system according to claim 3 , wherein the stylus TX signal transmitted by the stylus has a greater amplitude than the finger sensing TX signal.
5 . The stylus detecting system according to claim 4 , wherein the stylus TX signal ranges approximately between 20V-50V.
6 . The stylus detecting system according to claim 5 , wherein the finger sensing TX signal is less than 10V.
7 . The stylus detecting system according to claim 6 , wherein the finger sensing TX signal is more than 5 V.
8 . The stylus detecting system according to claim 3 , wherein the stylus TX signal is different in either frequency or phase from a TX signal from a TX drive circuit.
9 . The stylus detecting system according to claim 3 , wherein the stylus TX signal has a higher frequency than the finger sensing TX signal.
10 . The stylus detecting system according to claim 9 , wherein the stylus TX signal has at least double the upper frequency limit of the finger sensing TX signal.
11 . The stylus detecting system according to claim 3 , wherein the stylus TX signal has a different code for code modulation than a code used in a TX signal from a TX drive circuit.