Capacitive Touch Sensing Apparatus and Detection Method Thereof

• US 20110083911A1
• Filed: 05/11/2010
• Published: 04/14/2011
• Est. Priority Date: 10/14/2009
• Status: Abandoned Application

• Current Assignee: Novatek Microelectronics Corporation (Novatek Microelectronics Corp Limited)
• Original Assignee: Novatek Microelectronics Corporation (Novatek Microelectronics Corp Limited)
• Inventors: Hsu, Chih-Hsin, Tang, Wing-Kai
• Application Number:
  US12/777,271
• Publication Number:
  US 20110083911A1
• Time in Patent Office: Days
• US Class Current: 178/18.06
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/04186 Touch location disambiguation
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A capacitive touch sensing apparatus includes a plurality of sensing capacitor units, a control signal generation unit, a plurality of high impedance controllers, and a detection unit. The plurality of sensing capacitor units are utilized for generating a plurality of touch analog signals. The control signal generation unit is utilized for generating a plurality of control signals. The plurality of high impedance controllers are installed by intersections of a plurality of control signal lines and a plurality of signal transmission lines, where each of the high impedance controllers conducts a corresponding touch analog signal to a corresponding signal transmission line according to a corresponding control signal. The detection unit is utilized for determining whether a touch event occurs according to the conducted touch analog signal

Claims

1. A capacitive touch sensing apparatus, comprising:

a substrate;

a plurality of sensing capacitor units, disposed on the substrate, for generating a plurality of analog touch signals;

a plurality of control signal lines, parallel with each other and disposed along a first direction;

a plurality of signal transmission lines, parallel with each other and disposed along a second direction different from the first direction;

a control signal generation unit, coupled to the plurality of control signal lines, for generating a plurality of control signals transmitted through the plurality of control signal lines;

a plurality of high impedance controllers, respectively disposed by intersections of the plurality of control signal lines and the plurality of signal transmission lines, wherein each of the high impedance controllers comprises an input end coupled to a corresponding sensing capacitor unit, a control end coupled to a corresponding control signal line, and an output end coupled to a corresponding signal transmission line, for conducting a corresponding analog touch signal generated by the corresponding sensing capacitor unit to the corresponding signal transmission line according to the corresponding control signal; and

a detection unit, coupled to the plurality of signal transmission lines, for determining sensing variations of the plurality of sensing capacitor units according to the plurality of analog touch signals to detect whether a touch event occurs on the corresponding sensing capacitor unit.

2. The capacitive touch sensing apparatus of claim 1, wherein each of the sensing capacitor units comprises an electrode.

3. The capacitive touch sensing apparatus of claim 2, wherein the electrode is made of Indium Tin Oxide material.

4. The capacitive touch sensing apparatus of claim 1, wherein the first direction is perpendicular to the second direction.

5. The capacitive touch sensing apparatus of claim 1, wherein the control signal generation unit controls the plurality of control signals to take turns in the enable state to enable the corresponding high impedance controller coupled to the corresponding control signal line.

6. The capacitive touch sensing apparatus of claim 5, wherein the control signal generation unit controls the plurality of control signals to be in the enable state along the first direction by turns to enable the corresponding high impedance controller coupled to the corresponding control signal line.

7. The capacitive touch sensing apparatus of claim 1, wherein each of the analog touch signals comprises an environmental capacitance and a variation amount of touch sensing capacitance.

8. The capacitive touch sensing apparatus of claim 7, wherein the detection unit determines a sensing capacitor unit corresponding to one of the plurality of analog touch signals undergoing a touch event when the sum of the environmental capacitance and the variation amount of touch sensing capacitance of the corresponding analog touch signal is greater than a threshold value.

9. The capacitive touch sensing apparatus of claim 7, wherein the detection unit determines a sensing capacitor unit corresponding to one of the plurality of analog touch signal undergoing a touch event when the variation amount of touch sensing capacitance of the corresponding analog touch signal is greater than a threshold value.

10. The capacitive touch sensing apparatus of claim 1, wherein only one of the control signals is in an enable state at the same time.

11. A capacitive touch sensing apparatus, comprising:

a substrate;

a sensing capacitor unit, disposed on the substrate, for generating an analog touch signal;

a control signal generation unit, for generating a control signals;

a detection unit, for determining sensing variations of the sensing capacitor unit according to the analog touch signal to detect a touch event; and

a high impedance controller, coupled to the sensing capacitor unit, the control signal generation unit, and the detection unit, for conducting the analog touch signal to the detection unit according to the control signal.

12. The capacitive touch sensing apparatus of claim 11, wherein the sensing capacitor unit comprises an electrode.

13. The capacitive touch sensing apparatus of claim 12, wherein the electrode is made of Indium Tin Oxide material.

14. The capacitive touch sensing apparatus of claim 11, wherein the analog touch signals comprise an environmental capacitance and a variation amount of touch sensing capacitance.

15. The capacitive touch sensing apparatus of claim 14, wherein the detection unit determines the sensing capacitor unit undergoes a touch event when the sum of the environmental capacitance and the variation amount of touch sensing capacitance of the analog touch signal is greater than a threshold value.

16. The capacitive touch sensing apparatus of claim 14, wherein detection unit determines the sensing capacitor unit undergoes a touch event when the variation amount of touch sensing capacitance of the analog touch signal is greater than a threshold value.

17. A multi-touch detection method for a capacitive touch sensing apparatus, the capacitive touch sensing apparatus comprising a plurality of control signal lines, a plurality of signal transmission lines, a plurality of high impedance controllers, the plurality of control signal lines parallel with each other and disposed along a first direction, the plurality of signal transmission lines parallel with each other and disposed along a second direction different from the first direction, the plurality of high impedance controllers respectively disposed by intersections of the plurality of control signal lines and the plurality of signal transmission lines, the multi-touch detection method comprising:

generating a plurality of analog touch signals;

generating a plurality of control signals transmitted through the plurality of control signal lines;

conducting a corresponding analog touch signal to a corresponding signal transmission line according to a corresponding control signal by each of the corresponding high impedance controllers; and

determining whether sensing variation is occurring according to the conducted analog touch signal to detect a touch event.

18. The multi-touch detection method of claim 17, wherein the first direction is perpendicular to the second direction.

19. The multi-touch detection method of claim 17 further comprising:

controlling the plurality of control signals to take turns in the enable state to enable the corresponding high impedance controller coupled to the corresponding control signal line.

20. The multi-touch detection method of claim 19, wherein the step of controlling the plurality of control signals to take turns in the enable state to enable the corresponding high impedance controller coupled to the corresponding control signal line comprises controlling the plurality of control signals to be in the enable state along the first direction in turn to enable the corresponding high impedance controller coupled to the corresponding control signal line.

21. The multi-touch detection method of claim 17, wherein each of the analog touch signals comprises an environmental capacitance and a variation amount of touch sensing capacitance correspondingly.

22. The multi-touch detection method of claim 21, wherein the step of determining whether sensing variation occurs according to the conducted analog touch signal to detect the touch event comprises determining the touch event is detected when the sum of the environmental capacitance of the analog touch signal and the variation amount of touch sensing capacitance of the corresponding analog touch signal is greater than a threshold value.

23. The multi-touch detection method of claim 21, wherein the step of determining whether sensing variation occurs according to the conducted analog touch signal to detect the touch event comprises determining the touch event is detected when the variation amount of touch sensing capacitance of the corresponding analog touch signal is greater than a threshold value.

24. The multi-touch detection method of claim 17, wherein only one of the control signals is in an enable state at the same time.