Method of determining touch event in touch detection system
A method of determining a touch event in a touch detection system includes transmitting at least one driving signal to a touch panel of the touch detection system; receiving a sensing signal corresponding to the driving signal from the touch panel; determining whether the touch event occurs by performing an initial digital operation on the sensing signal; determining whether the sensing signal is interfered with by a noise signal; and performing an entire determination on the sensing signal when the touch event is determined to occur or the sensing signal is determined to be interfered with by the noise signal.
1. A method of determining a touch event in a touch detection system, comprising:
transmitting at least one driving signal to a touch panel of the touch detection system;
receiving a sensing signal corresponding to the at least one driving signal from the touch panel;
determining whether the touch event occurs by performing an initial digital operation on the sensing signal;
determining whether the sensing signal is interfered with by a noise signal;
performing an entire determination on the sensing signal after the touch event is determined to occur or the sensing signal is determined to be interfered with by the noise signal; and
not performing the entire determination on the sensing signal after the touch event is not determined to occur and the sensing signal is not determined to be interfered with by the noise signal.
2. The method of claim 1 , wherein the entire determination comprises a series of digital operations.
3. The method of claim 1 , wherein the entire determination comprises a maximum likelihood operation or a signal processing scheme using a filter.
4. The method of claim 1 , wherein the step of performing the initial digital operation on the sensing signal comprises:
performing a non-uniform sampling on the sensing signal.
5. The method of claim 4 , wherein the step of performing the non-uniform sampling on the sensing signal comprises:
deleting at least one fragment of the sensing signal before sampling the sensing signal, wherein the at least one fragment is interfered with by a regular noise.
6. The method of claim 5 , wherein an operation of the non-uniform sampling is described by a general form equation as follows:
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R
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∑
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=
∑
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A
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noise
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,
wherein R(t) denotes the sensing signal and is divided into a signal part A×g(t) and a noise part noise(t), g(t) is a basic signal, and sequence(t) denotes a sequence of time frames remained after the at least one fragment of the sensing signal is deleted.
7. The method of claim 1 , further comprising:
scheduling to reserve a plurality of digital operation periods for performing the initial digital operation and a plurality of entire determination periods for performing the entire determination alternately, wherein each of the plurality of digital operation periods is followed by one of the plurality of entire determination periods.
8. The method of claim 1 , wherein the entire determination provides a higher resolution than the initial digital operation.
9. The method of claim 1 , further comprising:
determining whether a plurality of determination results of the sensing signal are interfered with by the noise signal; and
selecting to use at least one of the plurality of determination results which is not determined to be interfered with by the noise signal to determine touch information related to the touch event.