Display panel, display device having the same and method of detecting touch position

• US 8,199,116 B2
• Filed: 09/11/2006
• Issued: 06/12/2012
• Est. Priority Date: 09/26/2005
• Status: Expired due to Fees

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Jeon, Jin, Kim, Hyung-Guel, Song, Jun-Ho
• Primary Examiner(s): Wang, Quan-Zhen
• Assistant Examiner(s): DAVIS, TONY O
• Application Number:
  US11/518,707
• Publication Number:
  US 20070070047A1
• Time in Patent Office: 2,101 Days
• Field of Search: 345/98, 345/102, 345/173
• US Class Current: 345/173
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• 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 display panel includes an array substrate and an opposite substrate. The array substrate includes pixels, first signal lines, and second signal lines. The opposite substrate is combined with the array substrate, interposing a liquid crystal layer there between. The opposite substrate includes an opposite base substrate and first and second protruded electrodes. The first and second protruded electrodes are formed in regions corresponding to the first and second signal lines, respectively, and are electrically connected to the first and second signal lines, respectively, based on an externally provided pressure. Therefore, a thickness of the display panel is decreased, and a touch position is easily detected.

Claims

1. A display panel comprising:

an array substrate including;

a plurality of gate lines;

a plurality of data lines crossing the gate lines;

a plurality of pixels driven by the gate lines and the data lines;

a plurality of first signal lines extended substantially in parallel with the gate lines;

a plurality of second signal lines extended substantially in parallel with the data lines;

an insulation layer covering the first and second signal lines;

a plurality of first sensing electrodes disposed on the insulation layer and electrically connected to the first signal lines; and

a plurality of second sensing electrodes disposed on the insulation layer and electrically connected to the second signal lines; and

an opposite substrate combined with the array substrate interposing a liquid crystal layer there between, the opposite substrate including;

an opposite base substrate; and

first and second protruded electrodes protruding from the opposite substrate and disposed overlapping the first and second sensing electrode, respectively,

wherein the first and second protruded electrodes contact the first and second sensing electrodes, respectively, to be electrically connected to the first and second signal lines, when applied with an externally provided pressure,

wherein the first and second protruded electrodes electrically are spaced apart from the first and second sensing electrodes, when not applied with an externally provided pressure.

2. The display panel of claim 1, wherein each of the first and second protruded electrodes comprises:

an insulating part protruded from the opposite base substrate; and

a common electrode layer covering the insulating part, the common electrode layer further covering the opposite base substrate.

3. The display panel of claim 1, wherein the first and second protruded electrodes comprise:

a common electrode layer covering a substantially entire surface of the opposite base substrate; and

a plurality of conductive parts on the common electrode layer.

4. The display panel of claim 1, wherein a thickness of the opposite base substrate is about 0.2 mm to about 0.5 mm.

5. The display panel of claim 1, wherein the array substrate further comprises a plurality of pixel electrodes defining the plurality of pixels, and the first and second sensing electrodes are formed from a substantially same layer as the plurality of pixel electrodes.

6. The display panel of claim 1, wherein the first signal lines further comprises a plurality of branch lines substantially in parallel with the data lines, and the first sensing electrodes are formed on the branch lines.

7. The display panel of claim 6, wherein at least two pixels are formed between adjacent branch lines and adjacent second signal lines.

8. The display panel of claim 6, wherein each of the branch lines and each of the second signal lines are between adjacent pixels.

9. The display panel of claim 8, wherein each of the first protruded electrodes is integrally formed with each of the second protruded electrodes.

10. The display panel of claim 1, further comprising a spacer maintaining a distance between the array substrate and the opposite substrate.

11. The display panel of claim 10, wherein the spacer comprises a column spacer.

12. The display panel of claim 10, wherein the spacer comprises a ball spacer.

13. The display panel of claim 1, wherein a height of each of the first and second protruded electrodes is less than a cell gap between the array substrate and the opposite substrate.

14. A display device comprising:

a display panel including;

an array substrate including a plurality of gate lines, a plurality of data lines, a plurality of first signal lines extended substantially in parallel with the gate lines, a plurality of second signal lines extended substantially in parallel with the data lines, an insulation layer covering the first and second signal lines, a plurality of first sensing electrodes disposed on the insulation layer and electrically connected to the first signal lines, and a plurality of second sensing electrodes disposed on the insulation layer and electrically connected to the second signal lines; and

an opposite substrate combined with the array substrate interposing a liquid crystal layer there between, the opposite substrate including an opposite base substrate, and first and second protruded electrodes protruding from the opposite substrate and disposed overlapping the first and second sensing electrodes, respectively, wherein the first and second protruded electrodes respectively contact the first and second sensing electrodes to be a plurality of protruded electrodes electrically connected to the first and second signal lines when applied with an externally provided pressure, wherein the first and second protruded electrodes are spaced apart from the first and second sensing electrodes, when not applied with an externally provided pressure;

a panel driving part which applies gate and data signals to the gate and data lines, respectively;

a touch position detecting part which detects first and second signal lines electrically connected to protruded electrodes to output a detection signal; and

a position determining part which determines position coordinates of the externally provided pressure based on the detection signal.

15. The display device of claim 14, wherein the panel driving part comprises:

a gate driving part which applies a plurality of gate signals to the gate lines, respectively;

a data driving part which applies a plurality of data signals to the data lines, respectively; and

a timing controlling part which controls timing of the gate and data signals.

16. The display device of claim 14, wherein the touch position detecting part comprises:

a voltage controlling part which controls application of an initial driving voltage to the first and second signal lines; and

a data sampling part which detects voltage variations of the first and second signal lines, and outputs a detection signal when the first and second signal lines are electrically connected to the first and second protruded electrodes, respectively, when applied with the externally provided pressure.

17. The display device of claim 16, wherein a common voltage is applied to the first and second protruded electrodes.

18. The display device of claim 16, wherein the data sampling part is electrically connected to each of the first and second signal lines.

19. The display device of claim 18, wherein the data sampling part comprises a latch.

20. The display device of claim 18, wherein the data sampling part comprises an operational amplifier.

21. The display device of claim 14, wherein the touch position detecting part is integrally formed with the panel driving part.

22. A method of detecting touch position on a display device, the method comprising:

applying an initial driving voltage to first and second sensing electrodes, which are disposed on an insulation layer covering first and second signal lines disposed on an array substrate, and are electrically connected to the first and second signal lines, respectively;

applying a pressure on an opposite substrate such that first and second protruded electrodes, which protrude from the opposite substrate and disposed overlapping the first and second sensing electrodes, respectively contact the first and second sensing electrodes to be electrically connected to the first and second signal lines, the first and second signal lines receiving a common voltage from the first and second protruded electrodes;

detecting the first and second signal lines electrically connected to the first and second protruded electrodes and outputting a first detection signal and a second detection signal, wherein a voltage level of the first and second signal lines is changed by a contact with the first and second protruded electrodes; and

determining position coordinates corresponding to the externally provided pressure based on the first and second detection signals,

wherein the first and second protruded electrodes are spaced apart from the first and second signal lines, respectively, when not applied with an externally provided pressure.

23. The method of claim 22, wherein applying the initial driving voltage to the first and second sensing electrodes comprises applying the initial driving voltage having a higher level than the common voltage.

24. The method of claim 23, wherein detecting the first and second signal lines electrically connected to the first and second protruded electrodes and outputting the first and second detection signals comprises latching a voltage level at a time when a changed voltage level of the first and second signal lines becomes a voltage level of the common voltage to generate the first and second detection signals.

25. The method of claim 22, wherein applying the initial driving voltage to the first and second sensing electrodes comprises applying the initial driving voltage having a lower level than the common voltage.

26. The method of claim 25, wherein detecting the first and second signal lines electrically connected to the first and second protruded electrodes and outputting the first and second detection signals comprises comparing a reference voltage with a changed voltage level of the first and second signal lines at a time when the changed voltage level of the first and second signal lines becomes a voltage level of the common voltage to amplify a voltage difference between the reference voltage and the changed level of the first and second signal lines, thereby generating the first and second detection signals.

27. The method of claim 22, wherein determining the position coordinates corresponding to the externally provided pressure based on the first and second detection signals comprises determining a crossing point between the first and second signal lines having a changed voltage level based on the first and second detection signals.

28. A display panel comprising:

an array substrate including;

a gate line;

a data line crossing the gate line;

a pixel driven by the gate line and the data line;

a first signal line extended substantially in parallel with the gate line;

a second signal line extended substantially in parallel with the data line;

an insulation layer covering the first and second signal lines;

a first sensing electrode disposed on the insulation layer and electrically connected to the first signal line; and

a second sensing electrode disposed on the insulation layer and electrically connected to the second signal line and

an opposite substrate combined with the array substrate interposing a liquid crystal layer there between, the opposite substrate including;

an opposite base substrate; and

a protruded electrode protruding from the opposite substrate and disposed overlapping the first and second sensing electrodes,

wherein the protruded electrode contacts the first and second sensing electrodes to be electrically connected to the first and second signal lines, when applied with an externally provided pressure, and

wherein the protruded electrode is spaced apart from the first and second sensing electrodes, when not applied with an externally provided pressure.