Touch detecting method and flat display device with in-cell touch panel

• US 8,976,143 B2
• Filed: 02/23/2011
• Issued: 03/10/2015
• Est. Priority Date: 05/18/2010
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Lee, Ping-Hwan, Hsu, Yu-Min, Cheng, Yung-Tse
• Primary Examiner(s): Sasinowski, Andrew
• Assistant Examiner(s): RAYAN, MIHIR K
• Application Number:
  US13/033,271
• Publication Number:
  US 20110285663A1
• Time in Patent Office: 1,476 Days
• Field of Search: 345/174
• US Class Current: 345/174
• 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
• CPC Class Codes: G06F 3/044 by capacitive means

Abstract

A touch detecting method comprises: enabling a sample signal in a period between driving a previous gate line and a previous two gate line before a corresponding gate line of a sense unit, and sampling a readout signal in a corresponding readout line during a sample period corresponding to the enabled sample signal by a readout unit; using the sampled readout signal during the sample period by the readout unit as a sample reference signal; enabling a sense readout signal in a period between driving the corresponding gate line of the sense unit and a next gate line, and reading out the readout signal during a sense readout period corresponding to the enabled sense readout signal; using the readout signal during the sense readout period as a sense signal; and judging whether the sense unit is touched according to the sample reference signal and the sense signal.

Claims

1. A touch detecting method applied into a flat display device with an in-cell touch panel, the flat display device comprising a plurality of gate lines, a plurality of data lines, a plurality of sense units and a plurality of readout lines, the gate lines being arranged crossing over with the data lines and thereby dividing the flat display device into a plurality of pixel regions, the sense units being disposed into some of the pixel regions, each of the sense units being electrically coupled to a corresponding one of the gate lines and thereby being driven by a gate signal on the corresponding gate line, and each of the sense units being further electrically coupled to a corresponding one of the readout lines so as to electrically couple to a readout unit, and the touch detecting method comprising:

enabling a sample signal during a period between driving the nearest gate line and driving the second nearest gate line preceding the corresponding gate line of one of the sense units, and sampling a readout signal by the readout unit on the corresponding readout line of the sense unit during a sample period corresponding to the sample signal being enabled, wherein the nearest gate line and the second nearest gate line preceding the corresponding gate line of one of the sense units are not connected to any one of the sense units;

using the readout signal sampled by the readout unit during the sample period as a sample reference signal;

enabling a sense readout signal during another period between driving the corresponding gate line and the nearest gate line succeeding the corresponding gate line of the sense unit, and reading out the readout signal by the readout unit on the corresponding readout line during a sense readout period corresponding to the sense readout signal being enabled, wherein the nearest gate line succeeding the corresponding gate line of the sense unit is not connected to any one of the sense units;

using the readout signal read out by the readout unit during the sense readout period as a sense signal; and

determining whether the sense unit is touched according to the sample reference signal and the sense signal;

wherein a capacitance-coupling influence caused by inputted gate signals of gate line driving in the sample reference signal has a polarity same to that of another capacitance-coupling influence caused by inputted gate signals of gate line driving in the sense signal when displaying a specific pattern, resulting from the sample signal being enabled during the period between driving the nearest gate line and driving the second nearest gate line preceding the corresponding gate line of one of the sense units, and the sense readout signal being enabled during the another period between driving the corresponding gate line and the nearest gate line succeeding the corresponding gate line of the sense unit.

2. The touch detecting method as claimed in claim 1, wherein the readout unit comprises:

an operational amplifier, comprising;

a positive input terminal electrically coupled to a reference voltage;

a negative input terminal electrically coupled to the corresponding readout line; and

an output terminal configured for outputting the sample reference signal or the sense signal;

a first capacitor electrically coupled between the negative input terminal and the output terminal of the operational amplifier;

a first switch electrically coupled between the negative input terminal and the output terminal of the operational amplifier and in parallel with the first capacitor;

a second switch electrically coupled to the output terminal of the operational amplifier;

a second capacitor electrically coupled between the second switch and a grounding potential, to receive and store the sample reference signal when the second switch is switched on;

a third switch electrically coupled to the output terminal of the operational amplifier;

a third capacitor electrically coupled between the third switch and the grounding potential, to receive and store the sense signal when the third switch is switched on; and

a processor electrically coupled to the second capacitor and the third capacitor to determine whether the sense unit is touched according to the sample reference signal and the sense signal.

3. The touch detecting method as claimed in claim 2, wherein every four of the gate lines in the flat display device are divided into a group, and the sense units are respectively electrically coupled to third gate lines of the groups.

4. The touch detecting method as claimed in claim 3, wherein the first switch is switched off when using the readout signal read out by the readout unit during the sense readout period as the sense signal.

5. The touch detecting method as claimed in claim 4, wherein the first switch is switched on when using the readout signal sampled by the readout unit during the sample period as the sample reference signal.

6. The touch detecting method as claimed in claim 4, wherein the first switch is switched off when using the readout signal sampled by the readout unit during the sample period as the sample reference signal.

7. The touch detecting method as claimed in claim 4, wherein

for the sense units corresponding to a first group of the gate lines, the first switch is switched on when using the readout signal sampled by the readout unit during the sample period as the sample reference signal;

and

for the sense units corresponding to the other groups of the gate lines, the first switch is switched off when using the readout signal sampled by the readout unit during the sample period as the sample reference signal.

8. A flat display device with in-cell touch panel, comprising:

a plurality of gate lines;

a plurality of data lines arranged crossing over the gate lines to divide the flat display device into a plurality of pixel regions;

a plurality of readout lines;

a plurality of sense units disposed in some of the pixel regions, and each of the sense units being electrically coupled to a corresponding one of the gate lines and thereby being driven by a gate signal on the corresponding gate line and further electrically coupled to a corresponding one of the readout lines; and

a plurality of readout units electrically coupled to the sense units respectively through the readout lines;

wherein when performing a touch detecting operation, a sample signal is enabled during a period between driving the nearest gate line and the second nearest gate line preceding the corresponding gate line of one of the sense units, a corresponding one of the readout units samples the corresponding readout line during a sample period corresponding to the sample signal being enabled to obtain a sample reference signal;

a sense readout signal is enabled during another period between driving the corresponding gate line and the nearest gate line succeeding the corresponding gate line of the sense unit, the corresponding readout unit samples the corresponding readout line during a sense readout period corresponding to the sense readout signal being enabled to obtain a sense signal, and then the sense unit whether is touched or not is determined according to the sample reference signal and the sense signal;

wherein the nearest gate line and the second nearest gate line preceding the corresponding gate line of one of the sense units are not connected to any one of the sense units, the nearest gate line succeeding the corresponding gate line of the sense unit is not connected to an one of the sense units;

wherein a capacitance-coupling influence caused by inputted gate signals of gate line driving in the sample reference signal has a polarity same to that of another capacitance-coupling influence caused by inputted gate signals of gate line drying in the sense signal when displaying a specific pattern, resulting from the sample signal being enabled during the period between driving the nearest gate line and driving the second nearest gate line preceding the corresponding gate line of one of the sense units, and the sense readout signal being enabled during the another period between driving the corresponding gate line and the nearest gate line succeeding the corresponding gate line of the sense unit.

9. The flat display device with in-cell touch panel as claimed in claim 8, wherein each of the readout unit comprises:

an operational amplifier, comprising;

a positive input terminal electrically coupled to a reference voltage;

a negative input terminal electrically coupled to the corresponding readout line; and

an output terminal configured for outputting the sample reference signal or the sense signal;

a first capacitor electrically coupled between the negative input terminal and the output terminal of the operational amplifier;

a first switch electrically coupled between the negative input terminal and the output terminal of the operational amplifier and in parallel with the first capacitor;

a second switch electrically coupled to the output terminal of the operational amplifier;

a second capacitor electrically coupled between the second switch and a grounding potential to receive and store the sample reference signal when the second switch is switched on;

a third switch electrically coupled to the output terminal of the operational amplifier;

a third capacitor electrically coupled between the third switch and the grounding potential to receive and store the sense signal when the third switch is switched on; and

a processor electrically coupled to the second capacitor and the third capacitor to judge whether the sense unit is touched according to the sample reference signal and the sense signal.

10. The flat display device with in-cell touch panel as claimed in claim 9, wherein every four of the gate lines in the flat display device are divided into a group, and the sense units are electrically coupled to third gate lines of the groups.

11. The flat display device with in-cell touch panel as claimed in claim 10, wherein the first switch is switched off when obtaining the sense signal.

12. The flat display device with in-cell touch panel as claimed in claim 11, wherein the first switch is switched on when obtaining the sample reference signal.

13. The flat display device with in-cell touch panel as claimed in claim 11, wherein the first switch is switched off when obtaining the sample reference signal.

14. The flat display device with in-cell touch panel as claimed in claim 11, wherein

for the sense units corresponding to a first group of the gate lines, the first switch is switched on when obtaining the sample reference signal;

and

for the sense units corresponding to the other groups of the gate lines, the first switch is switched off when obtaining the sample reference signal.

15. A touch detecting method applied into a flat display device with an in-cell touch panel, the flat display device comprising a plurality of gate lines, a plurality of data lines, a plurality of sense units and a plurality of readout lines, the gate lines being arranged crossing over with the data lines, the sense units being electrically connected to some of the gate lines while electrically unconnected to the others of the gate lines, and each of the sensing units further being electrically connected to a corresponding one of the readout lines, and the touch detecting method comprising:

obtaining a sample reference signal by sampling a readout signal from the corresponding readout line of one of the sense units in a period between sequentially driving two neighboring gate lines preceding a corresponding one of the gate lines which the sense unit electrically connected thereto, wherein the two neighboring gate lines are electrically unconnected to any one of the sense units;

obtaining a sense signal by sampling the readout signal from the corresponding readout line of the sense unit in another period between sequentially driving the corresponding gate line and the nearest gate line succeeding the corresponding gate line, wherein the nearest gate line is electrically unconnected to any one of the sense units; and

determining whether the sense unit is touched according to the sample reference signal and the sense signal;

wherein a capacitance-coupling influence caused by inputted gate signals of gate line driving in the sample reference signal has a polarity same to that of another capacitance-coupling influence caused by inputted gate signals of gate line driving in the sense signal when displaying a specific pattern, resulting from the sample reference signal being obtained by sampling a readout signal from the corresponding readout line of one of the sense units in a period between sequentially driving two neighboring gate lines preceding a corresponding one of the gate lines which the sense unit electrically connected thereto, and the sense signal being obtained by sampling the readout signal from the corresponding readout line of the sense unit in another period between sequentially driving the corresponding gate line and the nearest gate line succeeding the corresponding gate line.