LIQUID CRYSTAL DISPLAY DEVICE

• US 20110157504A1
• Filed: 11/23/2010
• Published: 06/30/2011
• Est. Priority Date: 12/25/2009
• Status: Active Grant

• Current Assignee: Japan Display Central Incorporated (Japan Display Incorporated)
• Original Assignee: Toshiba Mobile Display Company Limited (Japan Display Incorporated)
• Inventors: KIMURA, Hiroyuki, Kawamura, Tetsuya, Tabatake, Hiroshi
• Granted Patent: US 8,643,796 B2
• Time in Patent Office: Days
• US Class Current: 349/38
• CPC Class Codes: G02F 1/133707 Structures for producing distorted electric fields, e.g. bumps, protrusions, recesses, slits in pixel electrodes
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

In one embodiment, a liquid crystal display device having a plurality of pixels includes a first substrate having an insulating substrate, a first detection element extending in a first direction above the insulating substrate, a second detection element extending in a second direction crossing the first direction and an insulating film provided between the first and second detection circuits. A second substrate is arranged opposing to the first substrate so as to hold a liquid crystal layer therebetween. A detection circuit is provided on the first substrate to detect change of electrostatic capacitance between the first and second detection elements. At least one of the first and second detection elements is an element required for operating the liquid crystal layer.

Claims

1. A liquid crystal display device having a plurality of pixels, comprising:

a first substrate including;

an insulating substrate,

a signal line arranged above the insulating substrate and extending in a first direction,

a first insulating film covering the signal line,

a capacitance line arranged on the first insulating film and extending in a second direction crossing the first direction, the capacitance line including a slit formed above a portion of the signal line and extending in the first direction,

a second insulating film covering the capacitance line, and

a plurality of pixel electrodes arranged on the second insulating film so as to face the capacitance line, the respective pixel electrodes including a plurality of slits, and

a second substrate opposing to the first substrate;

a liquid crystal layer held between the first and second substrates; and

a detection circuit to detect change of electrostatic capacitance between the signal line and the capacitance line.

2. The liquid crystal display device according to claim 1, further comprising a gate line extending in the second direction, and a switching element electrically connected with the signal line, the gate line, and the pixel electrode.

3. The liquid crystal display device according to claim 1, further comprising an auxiliary capacitance line electrically connected with the capacitance line and extending in the second direction.

4. The liquid crystal display device according to claim 1, further comprising a transmissive mesh type shield electrode or a transmissive conductive paste arranged on an external surface of the second substrate opposing to the first substrate and a polalizer arranged on the external surface of the second substrate through the shield electrode or the transmissive conductive paste.

5. The liquid crystal display device according to claim 1, further comprising a driver IC chip including an image signal writing circuit to write the image signal into the pixel electrode and the detection circuit.

6. The liquid crystal display device according to claim 1, wherein the detection circuit writes a detection signal from one of the signal line and the capacitance line during a detection period successive to an image signal write-in period to write the image signal into the pixel electrode, and thereby detects the change of the electrostatic capacitance between the signal line and the capacitance line.

7. The liquid crystal display device according to claim 6, wherein the writing operation of the detection signal is simultaneously conducted for the plurality of signal lines or the capacitance lines.

8. A liquid crystal display device having a plurality of pixels, comprising:

a first substrate including;

an insulating substrate,

a capacitance line arranged above the insulating substrate and extending in a first direction,

an insulating film covering the capacitance line,

a plurality of pixel electrodes arranged above the insulating film so as to face the capacitance line, the respective pixel electrodes including a plurality of slits extending in a second direction crossing the first direction, and

a signal line arranged between adjacent pixel electrodes above the insulating film and extending in the second direction,

a second substrate opposing to the first substrate;

a liquid crystal layer held between the first and second substrates; and

a detection circuit to detect change of electrostatic capacitance between the signal line and the capacitance line.

9. The liquid crystal display device according to claim 8, wherein the signal line is a detection line.

10. The liquid crystal display device according to claim 8, further comprising a gate line extending in the first direction, a source line extending in the second direction, and a switching element electrically connected with the gate line, the source line, and the pixel electrode, wherein the signal line is arranged above the source line.

11. The liquid crystal display device according to claim 8, wherein a plurality of pixel electrodes are arranged between two adjacent signal lines in the first direction.

12. The liquid crystal display device according to claim 8, wherein the signal line and the pixel electrode are arranged in a same layer on the insulating film, or the signal line and the pixel electrode are respectively arranged in different layers through an interlayer insulating film on the insulating film.

13. The liquid crystal display device according to claim 8, further comprising a transmissive mesh type shield electrode or a transmissive conductive paste arranged on an external surface of the second substrate opposing to the first substrate and a polalizer arranged on the external surface of the second substrate through the shield electrode or the transmissive conductive paste.

14. The liquid crystal display device according to claim 8, further comprising a driver IC chip including an image signal writing circuit to write the image signal into the pixel electrode and the detection circuit.

15. The liquid crystal display device according to claim 8, wherein the detection circuit writes a detection signal from one of the signal line and the capacitance line during a detection period successive to an image signal write-in period to write the image signal into the pixel electrode, and thereby detects the change of the electrostatic capacitance between the signal line and the capacitance line.

16. The liquid crystal display device according to claim 15, wherein the writing operation of the detection signal is simultaneously conducted for the plurality of signal lines or the capacitance lines.

17. The liquid crystal display device according to claim 8, wherein the insulating film includes a concave portion and a convex portion.

18. The liquid crystal display device according to claim 17, wherein the signal line is arranged on the convex portion, and the pixel electrode is arranged on the concave portion.

19. The liquid crystal display device according to claim 17, wherein the signal line is arranged on the concave portion, and the pixel electrode is arranged on the convex portion.

20. A liquid crystal display device having a plurality of pixels, comprising:

a first substrate including;

an insulating substrate,

a capacitance line arranged on the insulating substrate and extending in a first direction,

a first insulating film covering the capacitance line,

a second insulating film formed on the first insulating film,

a switching element formed on the first insulating film and including a semiconductor layer, a gate electrode arranged on the semiconductor layer through a gate insulating film, and a source electrode and a drain electrode arranged on the second insulating film and connected with the semiconductor layer respectively,

a third insulating film covering the source and drain electrodes,

a plurality of pixel electrodes formed on the third insulating film and respectively connected with the drain electrode of the switching element through a contact hole formed in the third insulating film in the respective pixels so as to face the capacitance line, and

a signal line arranged between adjacent pixel electrodes on the second insulating film and extending in a second direction crossing the first direction,

wherein the capacitance line includes a slit formed above a portion of the signal line and extending in the second direction,

a second substrate opposing to the first substrate;

a liquid crystal layer held between the first and second substrates; and

a detection circuit to detect change of electrostatic capacitance between the signal line and the capacitance line.

21. The liquid crystal display device according to claim 20, further comprising a plurality of gate lines extending in the first direction, wherein the slit in the capacitance line is formed in two portions above the signal line extending to a center portion between adjacent gate lines in the second direction from portions near the respective gate lines.

22. The liquid crystal display device according to claim 20, wherein the liquid crystal layer is operated by the twisted nematic (TN) mode.

23. The liquid crystal display device according to claim 20, wherein the detection circuit writes a detection signal from one of the signal line and the capacitance line during a detection period successive to an image signal write-in period to write the image signal into the pixel electrode, and thereby detects change of the electrostatic capacitance between the signal line and the capacitance line.

24. A liquid crystal display device having a plurality of pixels, comprising:

a first substrate including;

an insulating substrate,

a capacitance line arranged on the insulating substrate and extending in a first direction,

a first insulating film covering the capacitance line,

a signal line formed on the first insulating film and extending in a second direction crossing the first direction,

a second insulating film covering the signal line,

a plurality of pixel electrodes formed on the second insulating film facing the capacitance line and having a plurality of slits extending in the second direction, the signal line being arranged between adjacent pixel electrodes in the first direction;

a second substrate opposing to the first substrate;

a liquid crystal layer held between the first and second substrates; and

a detection circuit to detect change of electrostatic capacitance between the signal line and the capacitance line.

25. A liquid crystal display device having a plurality of pixels, comprising:

a first substrate including an insulating substrate, a first detection element extending in a first direction above the insulating substrate, a second detection element extending in a second direction crossing the first direction and an insulating film provided between the first and second detection circuits,

a second substrate opposing to the first substrate;

a liquid crystal layer held between the first and second substrates; and

a detection circuit to detect change of electrostatic capacitance between the first and second detection elements;

wherein at least one of the first and second detection elements is an element required for operating the liquid crystal layer.