Liquid crystal display device and fabricating method thereof

• US 20070131936A1
• Filed: 06/13/2006
• Published: 06/14/2007
• Est. Priority Date: 12/14/2005
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Kang, Hee, Choo, Kyo
• Granted Patent: US 7,741,646 B2
• Time in Patent Office: Days
• US Class Current: 257/72
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/1354 having a particular photoconducting structure or material
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/136236 using a grey or half tone lithographic process
• CPC Class Codes: G02F 1/13624 having more than one switching element per pixel
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors

Abstract

A liquid crystal display panel and a fabricating method thereof comprising an image sensing capability, image scanning, and touch inputting. In the liquid crystal display device, a gate line and a data line are formed to intersect each other on a substrate to define a pixel area in which a pixel electrode is positioned. A first thin film transistor is positioned at an intersection area of the gate line and the data line. A sensor thin film transistor senses light having image information and supplied with a first driving voltage from the data line. A driving voltage supply line is positioned in parallel to the gate line to supply a second driving voltage to the sensor thin film transistor.

Claims

1. A liquid crystal display device, comprising:

a gate line and a data line crossing each other on a substrate to define a pixel area in which a pixel electrode is positioned;

a first thin film transistor at an intersection area of the gate line and the data line;

a sensor thin film transistor that senses light having image information and supplied with a first driving voltage from the data line; and

a driving voltage supply line substantially in parallel to the gate line to supply a second driving voltage to the sensor thin film transistor.

2. The liquid crystal display device as claimed in claim 1, further comprising:

a first storage capacitor for storing a pixel voltage charged into the pixel electrode;

a second storage capacitor for storing a signal sensed by the sensor thin film transistor;

an integrated circuit for extracting the sensing signal stored in the second storage capacitor;

a second thin film transistor connected to the second storage capacitor and the pre-stage gate line, and for selectively supplying the sensing signal to the integrated circuit; and

a sensing signal transmitting line substantially parallel to the data line with having the pixel area therebetween, and for transmitting a sensing signal from the second thin film transistor into the integrated circuit.

3. The liquid crystal display device as claimed in claim 2, wherein said sensor thin film transistor comprises:

a first gate electrode extended from the driving voltage supply line;

a gate insulating film formed in to cover the first gate electrode;

a first semiconductor pattern overlapped with the first gate electrode with the gate insulating film therebetween;

a first source electrode contacted with the first semiconductor pattern, and connected to the data line; and

a first drain electrode opposite the first source electrode.

4. The liquid crystal display device as claimed in claim 3, wherein said first drain electrode is formed in a “

U”

shape.

5. The liquid crystal display device as claimed in claim 2, wherein said first storage capacitor comprises:

a first lower storage electrode extended from the driving voltage supply line; and

a first upper storage electrode overlapped with the first lower storage electrode with the gate insulating film therebetween,

wherein the first upper storage electrode is contacted, via a first hole passing through a protective film, with the pixel electrode.

6. The liquid crystal display device as claimed in claim 3, wherein said second storage capacitor comprises:

a second-one storage capacitor consisted of a second storage electrode contacted with a first drain electrode of the sensor thin film transistor and the second thin film transistor, and the driving voltage supply line overlapped with the second storage electrode with the gate insulating film therebetween; and

a second-two storage capacitor overlapped with the second storage electrode with a protective film therebetween, and comprising a transparent electrode contacted, via a second hole for exposing the driving voltage supply line, with the driving voltage supply line.

7. The liquid crystal display device as claimed in claim 3, wherein said second thin film transistor comprises:

a second gate electrode contacted with the pre-stage gate line;

a second semiconductor pattern overlapped with the second gate electrode with the gate insulating film therebetween;

a second source electrode electrically connected to the second semiconductor pattern, and extended from the second storage electrode; and

a second drain electrode opposite to the second source electrode, and connected to the sensing signal transmitting line.

8. The liquid crystal display device as claimed in claim 2, wherein said first thin film transistor comprises:

a third gate electrode extended from the gate line;

a third semiconductor pattern formed in such a manner to overlap with the third gate electrode with the gate insulating film therebetween;

a third source electrode electrically connected to the third semiconductor pattern, and extended from the data line; and

a third drain electrode opposite to the third source electrode, and connected to the pixel electrode.

9. A method of fabricating a liquid crystal display device, comprising:

forming a gate pattern including a gate line, a first gate electrode of a sensor thin film transistor, a second gate electrode of a first thin film transistor, and a third gate electrode of a second thin film transistor on a first substrate;

forming a gate insulating film on a substrate provided with the gate pattern;

forming a first semiconductor pattern overlapped with the first gate electrode, a second semiconductor pattern overlapped with the second gate electrode, and a third semiconductor pattern overlapped with the third gate electrode on the gate insulating film;

forming a source/drain pattern including a data line crossing the gate line, a first source electrode and a first drain electrode connected to a first semiconductor pattern, and positioned in such a manner to oppose to each other, a second source electrode and a second drain electrode connected to a second semiconductor pattern, and positioned in such a manner to oppose to each other, and a third source electrode and a third drain electrode connected to a third semiconductor pattern, and positioned in such a manner to oppose to each other with the gate insulating film therebetween to provide a sensor thin film transistor, and a first and second thin film transistors;

forming a protective film having a first hole for exposing the second drain electrode of the first thin film transistor; and

forming a pixel electrode connected, via the first hole, to the second drain electrode,

wherein the first source electrode of the sensor thin film transistor and the second source electrode of the first thin film transistor are connected to the data line, respectively.

10. The method as claimed in claim 9, wherein said forming the gate pattern comprises:

forming a driving voltage supply line formed in parallel to the gate line to supply a driving voltage to the sensor thin film transistor, and

forming a first lower storage electrode in parallel to the gate line and extended from the driving voltage supply line.

11. The method as claimed in claim 9, wherein said forming the source/drain pattern comprises:

forming a first upper storage electrode formed in such a manner to overlap with the first lower storage electrode with the gate insulating film therebetween to consist of the first lower storage electrode and the first storage capacitor.

12. The method as claimed in claim 10, further comprising:

forming a second storage capacitor for storing a signal sensed by the sensor thin film transistor,

wherein said forming the second storage capacitor comprises;

forming a second-one storage capacitor including a second storage electrode positioned between the first drain electrode of the sensor thin film transistor and the second source electrode of the second thin film transistor, and the driving voltage supply line overlapped with the second storage electrode with the gate insulating film therebetween; and

forming a second-two storage capacitor overlapped with the second storage electrode with the second storage electrode and the protective film therebetween, and including a transparent electrode contacted, via a second hole for exposing the second driving voltage supply line, with the second driving voltage supply line.

13. The method as claimed in claim 9, wherein said step of forming the source/drain pattern comprises:

forming a sensing signal transmitting line positioned in parallel to the data line and connected to the third drain electrode of the second thin film transistor.

14. The method as claimed in claim 9, comprising:

preparing a second substrate positioned with the first substrate and the liquid crystal layer therebetween;

forming a black matrix for segmenting a cell area and preventing light leakage on the second substrate; and

forming a color filter at an cell area segmented by the black matrix.

15. The method as claimed in claim 14, wherein said black matrix is formed at an area except for a pixel area corresponding to the pixel electrode and a light receiving area for receiving light in the sensor thin film transistor.

16. A liquid crystal display device, comprising:

a thin film transistor array substrate and a color filter array substrate joined to each other with a liquid crystal layer therebetween, said thin film transistor array substrate further comprising;

a gate line and a data line crossing each other on a substrate to define a pixel area in which a pixel electrode is positioned;

a first thin film transistor at an intersection area of the gate line and the data line;

a sensor thin film transistor to sense light having image information and supplied with a first driving voltage from the pre-stage data line;

a driving voltage supply line substantially parallel to the gate line to supply a second driving voltage to the sensor thin film transistor;

a first storage capacitor for storing a pixel voltage charged into the pixel electrode;

a second storage capacitor for storing a signal sensed by the sensor thin film transistor;

an integrated circuit for extracting the sensing signal stored in the second storage capacitor;

a second thin film transistor connected to the second storage capacitor and the gate line, and for selectively supplying the sensing signal to the integrated circuit; and

a sensing signal transmitting line substantially parallel to the data line with the pixel area therebetween, and for transmitting a sensing signal from the second thin film transistor into the integrated circuit.

17. The liquid crystal display device as claimed in claim 16, wherein said color filter array substrate includes a black matrix for segmenting a cell area on the second substrate and for preventing light leakage;

and a color filter formed at a cell area segmented by the black matrix.

18. The liquid crystal display device as claimed in claim 17, wherein said black matrix is formed at an area except for a pixel area corresponding to the pixel electrode and a light receiving are for receiving a light in the sensor thin film transistor.