MULTI-RESOLUTION MICRO-WIRE TOUCH-SENSING DEVICE
A device for touch detection in a touch-screen device includes a surface having a touch-detection area, a plurality of independently controlled and electrically separate drive electrodes, and a plurality of independently controlled and electrically separate sense electrodes. The drive electrodes and sense electrodes define touch locations in the touch-detection area. A touch-detection circuit has a separate connection to each of the drive electrodes and a separate connection to each of the sense electrodes for detecting touches at a touch location in the touch-detection area. The touch-detection circuit controls three or more electrodes at the same time to detect a single sense signal responsive to the controlled three or more electrodes, the three or more electrodes including at least one drive electrode and at least one sense electrode. The device further includes a processor for analyzing the single sense signal and determining a touch at a touch location.
1 . A device for touch detection in a touch-screen device, comprising:
a surface having a touch-detection area;
a plurality of independently controlled and electrically separate drive electrodes;
a plurality of independently controlled and electrically separate sense electrodes, and wherein the drive electrodes and sense electrodes define touch locations in the touch-detection area; and
a touch-detection circuit having a separate connection to each of the drive electrodes and a separate connection to each of the sense electrodes for detecting touches at a touch location in the touch-detection area;
wherein the touch-detection circuit controls three or more electrodes at the same time to detect a single sense signal responsive to the controlled three or more electrodes, the three or more electrodes including at least one drive electrode and at least one sense electrode; and
a processor for analyzing the single sense signal and determining a touch at a touch location.
2 . The device of claim 1 , wherein the touch-detection circuit controls two or more drive electrodes with a common drive signal at the same time and detects a single sense signal with one or more sense electrodes at the same time.
3 . The device of claim 2 , wherein the touch-detection circuit includes a drive-control circuit having a value input specifying the two or more drive electrodes, a common drive signal input, and a separate output connected to each drive electrode.
4 . The device of claim 1 , wherein the touch-detection circuit controls one or more drive electrodes with a common drive signal at the same time and detects a single sense signal with two or more sense electrodes at the same time.
5 . The device of claim 4 , wherein the touch-detection circuit includes a sense-control circuit having a value input specifying the two or more sense electrodes, a sense-combining circuit input, and a combined single sense signal output.
6 . The device of claim 5 , wherein the sense-combining circuit includes an analog switch for each sense electrode, each analog switch having a sense-electrode input, a switch control input, and a sense output connected in common with the sense output of each of the analog switches.
7 . The device of claim 5 , wherein the sense-combining circuit includes a sample circuit for each sense electrode for storing a sampled value and a combining circuit for reading the sampled values corresponding to the value input.
8 . The device of claim 1 , wherein the touch-detection circuit controls two or more drive electrodes with a common drive signal at the same time and detects a single sense signal with two or more sense electrodes at the same time.
9 . The device of claim 1 , wherein two or more drive electrodes are adjacent or two or more sense electrodes are adjacent.
10 . The device of claim 1 , wherein:
the touch-detection circuit separately and sequentially controls each drive electrode with a drive signal;
for each controlled drive electrode, the touch-detection circuit separately detects a single sense signal for each sense electrode; and
the processor analyzes the single sense signals and determines a touch, thereby performing a high-resolution scan of the touch-detection area to determine a high-resolution touch at a touch location within a high-resolution touch area defined by the controlled one or more drive electrodes and sensed one or more sense electrodes.
11 . The device of claim 1 , wherein:
the electrodes are associated into electrode groups, at least one electrode group having three or more electrodes including at least one drive electrode and at least one sense electrode;
touch-detection circuit separately and sequentially controls each electrode group, wherein controlling each electrode group includes controlling the three or more electrodes in the electrode group at the same time to detect a single sense signal responsive to the controlled three or more electrodes; and
the processor analyzes the single sense signal of each electrode group to determine a touch, thereby performing a low-resolution scan of the touch-detection area to determine a low-resolution touch at a touch location within a low-resolution touch area defined by the controlled drive electrodes and controlled sense electrodes.
12 . The device of claim 11 , further including a storage element wherein the electrode groups are defined by values stored in the storage element.
13 . The device of claim 12 , wherein the values stored in the storage element define the drive electrode(s) in each electrode group and the sense electrode(s) in each electrode group.
14 . The device of claim 11 , further including a clock connected to a counter wherein the counter references a stored value specifying an electrode group.
15 . The device of claim 14 , further including a memory having an input address control connected to the counter and wherein the electrode groups are defined by values stored in the memory.
16 . The device of claim 11 , further including a storage element specifying a first set of electrode groups and a second set of electrode groups.
17 . The device of claim 16 , wherein the first set of electrode groups includes more electrodes than the second set of electrode groups.
18 . The device of claim 16 , wherein the second set of electrode groups is defined by a touch location detected in the first set of electrode groups.
19 . The device of claim 16 , wherein the first set of electrode includes all of the electrodes and the second set of electrode groups includes fewer than all of the electrodes.
20 . The device of claim 16 , further including a storage element storing a third set of electrode groups.