TOUCH CIRCUIT CHIP AND TOUCH APPARATUS USING THE SAME

• US 20140240275A1
• Filed: 07/08/2013
• Published: 08/28/2014
• Est. Priority Date: 02/07/2013
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: WANG, Chao-Chen, CHEN, Chao-Chuan, TUN, KYAW KYAW
• Granted Patent: US 9,329,735 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G01D 18/004 Continuous recalibration
• CPC Class Codes: G01D 5/24 by varying capacitance
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• 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 touch circuit chip includes a load adjustment unit and a comparator. The load adjustment unit adjusts a determined impedance value according to an impedance matching signal. The first comparator has a first end electrically coupled to a first load and from which to receive a sensing signal, a second end electrically coupled to a second load via the load adjustment unit and from which to receive a reference signal, and an output end. The comparator compares the received sensing signal with the received reference signal and accordingly output a comparison result. The touch circuit chip determines whether there exists a change of a capacitance value of a coupling capacitor between the first and second loads according to the comparison result, wherein the determined impedance value is matched to the impedance value of the coupling capacitor and the first load. A touch apparatus is also provided.

Claims

1. A touch circuit chip, comprising:

a load adjustment unit configured to adjust a determined impedance value according to an impedance matching signal; and

a first comparator having a first end, a second end and an output end, the first end of the first comparator being electrically coupled to a first load and from which to receive a sensing signal, the second end of the first comparator being electrically coupled to a second load via the load adjustment unit and from which to receive a reference signal, the first comparator being configured to compare a voltage of the received sensing signal with a voltage of the received reference signal and accordingly output a comparison result via the output end thereof, the touch circuit chip being configured to determine whether there exists a change of a capacitance value of a coupling capacitor between the first and second loads according to the comparison result,

wherein the determined impedance value is matched to the impedance value of the coupling capacitor and the first load.

2. The touch circuit chip according to claim 1, wherein the impedance matching signal comprises at least a first control signal, at least a second control signal and at least a third control signal, and the load adjustment unit comprises:

a first capacitor module having a first end and a second end, the first end of the first capacitor module being electrically coupled to the second load and from which to receive the reference signal, the first capacitor module being configured to adjust a capacitance value thereof according to the first control signal;

a second capacitor module having a first end and a second end, the first end of the second capacitor module being electrically coupled to the second end of the first capacitor module, the second end of the second capacitor module being electrically coupled to ground, the second capacitor module being configured to adjust a capacitance value thereof according to the second control signal; and

a resistor module having a first end and a second end, the first end of the resistor module being electrically coupled to the first end of the second capacitor module, the second end of the resistor module being electrically coupled to the second end of the first comparator, the resistor module being configured to adjust a resistance value thereof according to the third control signal.

3. The touch circuit chip according to claim 2, wherein the first capacitor module comprises a plurality of capacitors, the capacitors are arranged in parallel and corporately electrically coupled to the second end of the first capacitor module by one ends thereof and corporately electrically coupled to the first end of the first capacitor module by the other ends thereof via a plurality of switches respectively, wherein the switches are controlled by the first control signal.

4. The touch circuit chip according to claim 2, wherein the second capacitor module comprises a plurality of capacitors, the capacitors are arranged in parallel and corporately electrically coupled to the second end of the second capacitor module by one ends thereof and corporately electrically coupled to the first end of the second capacitor module by the other ends thereof via a plurality of switches respectively, wherein the switches are controlled by the second control signal.

5. The touch circuit chip according to claim 2, wherein the resistor module comprises a plurality of resistors, the resistors are arranged in parallel and corporately electrically coupled to the second end of the resistor module by one ends thereof and corporately electrically coupled to the first end of the resistor module by the other ends thereof via a plurality of switches respectively, wherein the switches are controlled by the third control signal.

6. The touch circuit chip according to claim 2, further comprising:

a dynamic detection unit, electrically coupled to the first load through a switch, configured to detect an impedance value of the first load and the coupling capacitor and accordingly output a detection information; and

a control unit, electrically coupled to the dynamic detection unit, configured to receive the detection information from the dynamic detection unit, compare the detection information with a lookup table stored therein and accordingly output the first control signal, the second control signal and the third control signal,

wherein the switch is switched-off while the predetermined impedance value of the load adjustment unit is adjusted to match to the impedance value of the first load and the coupling capacitor.

7. The touch circuit chip according to claim 6, wherein the dynamic detection unit is further configured to calculate the impedance value of the first load and the coupling capacitor according to a voltage, a current or the both and thereby generate the detection information.

8. The touch circuit chip according to claim 1, further comprising:

a readout amplification unit, electrically coupled to the output end of the first comparator, configured to amplify the comparison result outputted from the first comparator and accordingly generate an amplification signal, wherein the touch circuit chip determines whether there exists a change of the capacitance value of the coupling capacitor according to the amplification signal generated by the readout amplification unit.

9. The touch circuit chip according to claim 8, wherein the readout amplification unit comprises:

a second comparator having a first end, a second end and an output end, the first end of the second comparator being electrically coupled to the output end of the first comparator, and the second end of the second comparator being electrically coupled to ground; and

a capacitor having a first end and a second end, the first end of the capacitor being electrically coupled to the first end of the second comparator, and the second end of the capacitor being electrically coupled to the output end of the second comparator.

10. The touch circuit chip according to claim 1, wherein the output end of the first comparator is electrically coupled to ground via a capacitor.

11. The touch circuit chip according to claim 1, wherein one end of the second load is electrically coupled to a signal source and from which to receive a driving signal.

12. A touch apparatus, comprising:

a touch panel comprising a plurality of driving electrodes and a plurality of sensing electrodes arranged in an intersection manner, and a coupling capacitor being formed at each of intersecting points resulted by the intersection of the driving electrodes and the sensing electrodes; and

a touch circuit chip electrically coupled to the touch panel, the touch circuit chip comprising;

a load adjustment unit configured to adjust a determined impedance value according to an impedance matching signal, and the determined impedance value being matched to an impedance value of the coupling capacitor and one of the sensing electrode; and

a first comparator having a first end, a second end and an output end, the first end of the first comparator being electrically coupled to one of the sensing electrodes and from which to receive a sensing signal, the second end of the first comparator being electrically coupled to one of the driving electrodes via the load adjustment unit and from which to receive a reference signal, the first comparator being configured to compare a voltage of the received sensing signal with a voltage of the received reference signal and accordingly output a comparison result via the output end thereof, the touch circuit chip being configured to determine whether there exists a change of a capacitance value of the coupling capacitors according to the comparison result.

13. The touch apparatus according to claim 12, wherein the impedance matching signal comprises at least a first control signal, at least a second control signal and at least a third control signal, and the load adjustment unit comprises:

a first capacitor module having a first end and a second end, the first end of the first capacitor module being electrically coupled to one of the driving electrodes and from which to receive the reference signal, the first capacitor module being configured to adjust a capacitance value thereof according to the first control signal;

a second capacitor module having a first end and a second end, the first end of the second capacitor module being electrically coupled to the second end of the first capacitor module, the second end of the second capacitor module being electrically coupled to ground, the second capacitor module being configured to adjust a capacitance value thereof according to the second control signal; and

a resistor module having a first end and a second end, the first end of the resistor module being electrically coupled to the first end of the second capacitor module, the second end of the resistor module being electrically coupled to the second end of the first comparator, the resistor module being configured to adjust a resistance value thereof according to the third control signal.

14. The touch apparatus according to claim 13, wherein the first capacitor module comprises a plurality of capacitors, the capacitors are arranged in parallel and corporately electrically coupled to the second end of the first capacitor module by one ends thereof and corporately electrically coupled to the first end of the first capacitor module by the other ends thereof via a plurality of switches respectively, wherein the switches are controlled by the first control signal.

15. The touch apparatus according to claim 13, wherein the second capacitor module comprises a plurality of capacitors, the capacitors are arranged in parallel and corporately electrically coupled to the second end of the second capacitor module by one ends thereof and corporately electrically coupled to the first end of the second capacitor module by the other ends thereof via a plurality of switches respectively, wherein the switches are controlled by the second control signal.

16. The touch apparatus according to claim 13, wherein the resistor module comprises a plurality of resistors, the resistors are arranged in parallel and corporately electrically coupled to the second end of the resistor module by one ends thereof and corporately electrically coupled to the first end of the resistor module by the other ends thereof via a plurality of switches respectively, wherein the switches are controlled by the third control signal.

17. The touch apparatus according to claim 13, further comprising:

a dynamic detection unit, electrically coupled to one of the sensing electrodes through a switch, configured to detect an impedance value of one of the sensing electrodes and the respective coupling capacitor and accordingly output a detection information; and

a control unit, electrically coupled to the dynamic detection unit, configured to receive the detection information from the dynamic detection unit, compare the detection information with a lookup table stored therein and accordingly output the first control signal, the second control signal and the third control signal,

wherein the switch is switched-off while the predetermined impedance value of the load adjustment unit is adjusted to match to the impedance value of one of the sensing electrodes and the coupling capacitor.

18. The touch apparatus according to claim 17, wherein the dynamic detection unit is further configured to calculate the impedance value of one of the sensing electrodes and the coupling capacitor according to a voltage, a current or the both and thereby generate the detection information.

19. The touch apparatus according to claim 12, wherein the touch circuit chip further comprises:

a readout amplification unit, electrically coupled to the output end of the first comparator, configured to amplify the comparison result outputted from the first comparator and accordingly generate an amplification signal, wherein the touch circuit chip determines whether there exists a change of the capacitance value of the coupling capacitor according to the amplification signal generated by the readout amplification unit.

20. The touch apparatus according to claim 19, wherein the readout amplification unit comprises:

a second comparator having a first end, a second end and an output end, the first end of the second comparator being electrically coupled to the output end of the first comparator, and the second end of the second comparator being electrically coupled to ground; and

a capacitor having a first end and a second end, the first end of the capacitor being electrically coupled to the first end of the second comparator, and the second end of the capacitor being electrically coupled to the output end of the second comparator.

21. The touch apparatus according to claim 12, wherein the output end of the first comparator is electrically coupled to ground via a capacitor.

22. The touch apparatus according to claim 12, wherein one end of the second load is electrically coupled to a signal source and from which to receive a driving signal.