TOUCH-PANEL-INTEGRATED LIQUID CRYSTAL DISPLAY AND METHOD OF DRIVING THE SAME

• US 20080278451A1
• Filed: 10/30/2007
• Published: 11/13/2008
• Est. Priority Date: 05/07/2007
• Status: Abandoned Application

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: LEE, Ki-chan
• Application Number:
  US11/927,775
• Publication Number:
  US 20080278451A1
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/047 using sets of wires, e.g. crossed wires

Abstract

A touch-panel-integrated liquid crystal display (“LCD”) which prevents malfunction of a sensor by decoupling coupling noise, and a method of driving the touch-panel-integrated LCD. The touch-panel-integrated LCD includes a plurality of first lines which extend in a first direction, a plurality of second lines which extend in a second direction that intersects the first direction, a plurality of thin film transistors which are respectively disposed at interconnections between the first lines and the second lines, a first comparator which includes first and second nodes, a first sensor line which is connected to the first node, extends in the same direction as the first lines, and transmits a touch signal corresponding to the first direction, and a first decoupler which is connected between the second node and one of the first lines and decouples coupling noise present in the touch signal corresponding to the first direction.

Claims

1. A touch-panel-integrated liquid crystal display comprising:

a plurality of first lines which extend in a first direction;

a plurality of second lines which extend in a second direction that intersects the first direction;

a plurality of thin film transistors which are respectively disposed at interconnections between the first lines and the second lines;

a first comparator which comprises first and second nodes;

a first sensor line which is connected to the first node, extends in a same direction as the first lines, and transmits a touch signal corresponding to the first direction; and

a first decoupler which is connected between the second node and one of the first lines and decouples coupling noise present in the touch signal corresponding to the first direction.

2. The touch-panel-integrated liquid crystal display of claim 1, further comprising:

a second comparator which comprises third and fourth nodes;

a second sensor line which is connected to the third node, extends in a same direction as the second lines, and transmits a touch signal corresponding to the second direction; and

a second decoupler which is connected between the fourth node and one of the second lines and decouples coupling noise present in the touch signal corresponding to the second direction.

3. The touch-panel-integrated liquid crystal display of claim 1, further comprising:

a second comparator which comprises third and fourth nodes;

a second sensor line which is connected to the third node, extends in a same direction as the second lines, and transmits a touch signal corresponding to the second direction; and

a dummy sensor line which is connected to the fourth node and extends in the same direction as the second lines.

4. The touch-panel-integrated liquid crystal display of claim 1, further comprising:

a second comparator which comprises third and fourth nodes;

a second sensor line which is connected to the third node, extends in a same direction as the second lines, and transmits a touch signal corresponding to the second direction;

a common electrode; and

a second decoupler which is connected between the fourth node and the common electrode, and decouples coupling noise present in a common voltage that is applied to the common electrode.

5. The touch-panel-integrated liquid crystal display of claim 1, wherein the first decoupler comprises a decoupling impedance.

6. The touch-panel-integrated liquid crystal display of claim 5, wherein the first decoupler comprises a decoupling resistor and a decoupling capacitor.

7. The touch-panel-integrated liquid crystal display of claim 1, further comprising a driver integrated circuit, wherein the first decoupler is installed in the driver integrated circuit.

8. The touch-panel-integrated liquid crystal display of claim 1, wherein the first lines, the second lines, the thin film transistors, the first comparator, the first sensor line, and the first decoupler are formed on a substrate.

9. A touch-panel-integrated liquid crystal display comprising:

a plurality of first lines which extend in a first direction;

a plurality of second lines which extend in a second direction that intersects the first direction;

a plurality of thin film transistors which are respectively disposed at interconnections between the first lines and the second lines;

a first comparator which comprises first and second nodes;

a first sensor line which is connected to the first node, extends in a same direction as the first lines, and transmits a touch signal corresponding to the first direction;

a common electrode; and

a first decoupler which is connected between the second node and the common electrode, and decouples coupling noise present in a common voltage that is applied to the common electrode.

10. The touch-panel-integrated liquid crystal display of claim 9, further comprising:

a second comparator which comprises third and fourth nodes;

a second sensor line which is connected to the third node, extends in a same direction as the second lines, and transmits a touch signal corresponding to the second direction; and

a second decoupler which is connected between the fourth node and the common electrode and decouples the coupling noise present in the common voltage.

11. The touch-panel-integrated liquid crystal display of claim 9, further comprising:

a second comparator which comprises third and fourth nodes;

a second sensor line which is connected to the third node, extends in a same direction as the second lines, and transmits a touch signal corresponding to the second direction; and

a dummy sensor line which is connected to the fourth node and extends in the same direction as the second lines.

12. The touch-panel-integrated liquid crystal display of claim 9, wherein the first decoupler comprises a voltage divider.

13. A touch-panel-integrated liquid crystal display comprising:

a plurality of first lines which extend in a first direction;

a plurality of second lines which extend in a second direction that intersects the first direction;

a plurality of thin film transistors which are respectively disposed at interconnections between the first lines and the second lines;

a first comparator which comprises first and second nodes;

a second comparator which comprises third and fourth nodes;

a first sensor line which is connected to the first node, extends in a same direction as the first lines, and transmits a touch signal corresponding to the first direction;

a second sensor line which is connected to the third node, extends in a same direction as the second lines, and transmits a touch signal corresponding to the second direction;

a first decoupler which is connected between the second node and one of the first lines and decouples coupling noise present in the touch signal corresponding to the first direction; and

a second decoupler which is connected between the fourth node and one of the second lines, and decouples coupling noise present in the touch signal corresponding to the second direction.

14. The touch-panel-integrated liquid crystal display of claim 13, further comprising a driver integrated circuit, wherein one of the first decoupler and the second decoupler is installed in the driver integrated circuit.

15. The touch-panel-integrated liquid crystal display of claim 13, further comprising a gate driver integrated circuit and a source driver integrated circuit wherein the first decoupler and the second decoupler are respectively integrated in the gate driver integrated circuit and the source driver integrated circuit.

16. The touch-panel-integrated liquid crystal display of claim 13, wherein the first lines, the second lines, the thin film transistors, the first comparator, the second comparator, the first sensor line, the second sensor line, the first decoupler, and the second decoupler are formed on a substrate.

17. A method of driving a touch-panel-integrated liquid crystal display, the method comprising:

providing a touch-panel-integrated liquid crystal display comprising a plurality of first lines which extend in a first direction, a plurality of second lines extend in a second direction that intersects the first direction, a plurality of thin film transistors which are respectively disposed at interconnections between the first lines and the second lines, a first comparator which comprises first and second nodes, a first sensor line which is connected to the first node, extends in the first direction, and transmits a touch signal corresponding to the first direction, and a first decoupler which is connected between the second node and one of the first lines and decouples coupling noise present in the touch signal corresponding to the first direction; and

applying external pressure to a touch panel of the touch-panel-integrated liquid crystal display, generating a signal which is a same as the coupling noise present in the touch signal corresponding to the first direction, and outputting the decoupled touch signal by applying the generated signal to an input terminal of the first comparator.

18. A method of driving a touch-panel-integrated liquid crystal display, the method comprising:

providing a touch-panel-integrated liquid crystal display comprising a plurality of first lines which extend in a first direction, a plurality of second lines extend in a second direction that intersects the first direction, a plurality of thin film transistors which are respectively disposed at interconnections between the first lines and the second lines, a first comparator which comprises first and second nodes, a first sensor line which is connected to the first node, extends in the first direction, and transmits a touch signal corresponding to the first direction, a common electrode, and a decoupler which is connected between the second node and the common electrode, and decouples coupling noise present in a common voltage that is applied to the common electrode; and

applying external pressure to a touch panel of the touch-panel-integrated liquid crystal display, reducing the common voltage, and outputting the decoupled common voltage by applying the reduced common voltage to an input terminal of the first comparator.