TOUCH SENSING APPARATUS AND METHOD

• US 20110042152A1
• Filed: 08/19/2009
• Published: 02/24/2011
• Est. Priority Date: 08/19/2009
• Status: Active Grant

• Current Assignee: Silicon Integrated Systems Corporation (Silicon Integrated Systems Corporation Taiwan)
• Original Assignee: U-Pixel Technologies, Inc.
• Inventors: Wu, Hung-Wei
• Granted Patent: US 8,791,907 B2
• Time in Patent Office: Days
• US Class Current: 178/18.03
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184

Abstract

A touch sensing apparatus utilizes the characteristics of orthogonal vectors is disclosed. A random spread spectrum (RSS) signal or a periodic wave is used to modulate a driving signal so as to driving a row of a sensing array, and the RSS signal or periodic wave is also use to extract touch information of a node from a sensing signal measured from a column of the sensing array. The node is an intersection of the driven row and the measured column. When different RSS signals and/or periodic waves are used to drive multiple rows simultaneously, multipoint touching information can be obtained from the same sensing signal at the same time by respectively using the RSS signals and/or periodic waves to extract touching information of multiple points which are the intersections of the driven rows and the measured column.

Claims

1. A touching sensing apparatus comprising:

a sensing array having multiple rows and multiple columns intersecting with each other to define multiple nodes;

a driving circuit for providing a driving signal which is modulated by a modulation signal to drive a row of the sensing array; and

a sensing circuit receiving a sensing signal measured from a column of the sensing array and extracting touching information of a node, which is an intersection of the driven row and the measured column by using the modulation signal.

2. The touch sensing apparatus of claim 1, wherein the driving circuit comprises a pseudorandom noise (PN) code generator for providing a PN code as the modulation signal.

3. The touch sensing apparatus of claim 1, wherein the PN code generator comprises a linear feedback register (LFSR) random code generator.

4. The touch sensing apparatus of claim 1, wherein the driving circuit comprises a periodic wave generator for providing a periodic wave as the modulation signal.

5. The touch sensing apparatus of claim 4, wherein the periodic wave is a square wave.

6. The touch sensing apparatus of claim 4, wherein the periodic wave is a sine wave.

7. A touching sensing apparatus comprising:

a sensing array having multiple rows and multiple columns intersecting with each other to define multiple nodes;

a plurality of driving circuits, each for providing a driving signal, which is modulated by a modulation signal, to drive a row of the sensing array; and

a plurality of sensing circuits, each receiving a sensing signal measured from a column of the sensing array and extracting touching information of a node, which is an intersection of the driven row and the measured column, by using the modulation signal used by a corresponding one of the driving circuits,

wherein the respective driving circuits provide different modulated driving signals modulated with different modulation signals to drive different rows of the sensing array, and the sensing signal of the measured column is provided to the respective sensing circuits.

8. The touch sensing apparatus of claim 7, wherein each driving circuit comprises a pseudorandom noise (PN) code generator for providing a PN code as the modulation signal, the respective PN code generators provide different PN codes as the modulation signals.

9. The touch sensing apparatus of claim 7, wherein each driving circuit comprises a periodic wave generator for providing a periodic wave as the modulation signal, the respective periodic wave generators provide periodic waves of different frequencies as the modulation signals.

10. The touch sensing apparatus of claim 9, wherein the different frequencies are separated from each other by an interval of at least 10 kHz.

11. The touch sensing apparatus of claim 9, wherein the periodic waves are square waves.

12. The touch sensing apparatus of claim 9, wherein the periodic waves are sine waves.

13. The touch sensing apparatus of claim 7, wherein some of the driving circuits comprise PN code generators for respectively providing different PN codes, and the other driving circuits comprises periodic wave generators for respectively providing periodic waves of different frequencies.

14. The touch sensing apparatus of claim 13, wherein the PN code generators and the periodic wave generators are arranged alternately.

15. The touch sensing apparatus of claim 13, wherein the periodic waves are square waves of different frequencies.

16. The touch sensing apparatus of claim 13, wherein the periodic waves are sine waves of different frequencies.

17. A touching sensing apparatus comprising:

a sensing array having multiple rows and multiple columns intersecting with each other to define multiple nodes;

a plurality of driving circuits, each for providing a driving signal, which is modulated with a modulation signal and comprising;

a PN code generator for providing a PN code;

a periodic wave generator for providing a periodic wave;

a first multiplexer for selecting the PN code or the periodic wave as the modulation signal; and

a plurality of sensing circuits, each receiving a sensing signal measured from a column of the sensing array and extracting touching information of a node, which is an intersection of the driven row and the measured column, by using the modulation signal provided by a corresponding one of the driving circuits,

wherein the respective driving circuits provide different modulation signals so as to generate different modulated driving signals to drive different rows of the sensing array, and the sensing signal of the measured column is provided to the demodulators of the respective signal processing units, and the sensing signal of the measured column is provided to the respective sensing circuits.

18. The touch sensing apparatus of claim 17, wherein each sensing circuit comprises:

a first demodulator receiving the sensing signal measured from the column of the sensing array and demodulating the sensing signal with the same PN code;

a second demodulator receiving a sensing signal measured from a column of the sensing array and demodulating the sensing signal with the same periodic wave; and

a second multiplexer for selecting an output of the first or second demodulator depending on which of the PN code and the periodic wave is selected as the modulation signal.

19. The touch sensing apparatus of claim 17, wherein the first multiplexer of each driving circuit makes different selections at different times.

20. The touch sensing apparatus of claim 17, wherein each periodic wave is a square wave.

21. The touch sensing apparatus of claim 17, wherein each periodic wave is a sine wave.

22. A touching sensing apparatus comprising:

a sensing array having multiple rows and multiple columns intersecting with each other to define multiple nodes;

a signal source for providing a driving signal; and

a plurality of channels, each channel comprising;

a plurality of driving circuits, each for providing a driving signal, which is modulated by a modulation signal, to drive a row of the sensing array; and

a plurality of sensing circuits, each receiving a sensing signal measured from a column of the sensing array and extracting touching information of a node, which is an intersection of the driven row and the measured column, by using the modulation signal used by a corresponding one of the driving circuits,

wherein the respective driving circuits of each channel provide different modulated driving signals modulated with different modulation signals to drive different rows of the sensing array, and the sensing signals measured from the columns are provided to the respective sensing circuits at a time.

23. The touch sensing apparatus of claim 22, wherein each driving circuit comprises a pseudorandom noise (PN) code generator for providing a PN code as the modulation signal, the respective PN code generators provide different PN codes as the modulation signals.

24. The touch sensing apparatus of claim 23, wherein some channels share the PN code generators of the respective driving circuits.

25. The touch sensing apparatus of claim 22, wherein each driving circuit comprises a periodic wave generator for providing a periodic wave as the modulation signal, the respective periodic wave generators provide periodic waves of different frequencies as the modulation signals.

26. The touch sensing apparatus of claim 25, wherein some channels share the periodic wave generators of the respective driving circuits.

27. A touching sensing apparatus comprising:

a sensing array having multiple rows and multiple columns intersecting with each other to define multiple nodes;

a plurality of channels, each channel comprising;

a plurality of driving circuits, each for providing a driving signal, which is modulated with a modulation signal and comprising;

a PN code generator for providing a PN code;

a periodic wave generator for providing a periodic wave;

a first multiplexer for selecting the PN code or the periodic wave as the modulation signal; and

a plurality of sensing circuits, each receiving a sensing signal measured from a column of the sensing array and extracting touching information of a node, which is an intersection of the driven row and the measured column, by using the modulation signal provided by a corresponding one of the driving circuits,

wherein the respective driving circuits of each channel provide different modulated driving signals modulated with different modulation signals to drive different rows of the sensing array, and the sensing signals measured from the columns are provided to the respective sensing circuits at a time.

28. The touch sensing apparatus of claim 27, wherein some channels share the PN code generators and the periodic wave generators of the respective driving circuits.

29. A method for sensing a touch event to a touch sensing apparatus having a sensing array, the method comprising:

providing at a driving signal modulated by a modulation signal to drive at least one trace of the sensing array; and

using the same modulation signal to extract touching information of the driven trace.

30. The method of claim 29, wherein the modulation signal comprises a random spread spectrum signal.

31. The method of claim 29, wherein the at least one modulation signal comprises at least one periodic wave.

32. A method for sensing a plurality of touch events to at least one touch sensing apparatus having a sensing array, the method comprising:

providing a plurality of driving signals respectively modulated by different modulation signals to drive a plurality of traces of the sensing array; and

respectively using the same modulation signals to extract touching information of the driven traces.

33. The method of claim 32, wherein the modulation signals comprise different random spread spectrum signals.

34. The method of claim 32, wherein the modulation signals comprise periodic waves of different frequencies.

35. The method of claim 32, wherein the modulation signals comprise different random spread spectrum signals and periodic waves of different frequencies.