Liquid crystal display including sensing unit

• US 7,692,729 B2
• Filed: 07/26/2006
• Issued: 04/06/2010
• Est. Priority Date: 08/04/2005
• Status: Expired due to Fees

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Joo-Hyung, Pak, Sang-Jin, Uh, Kee-Han, Lee, Myung-Woo
• Primary Examiner(s): Pak; Sung H
• Assistant Examiner(s): SMITH, CHAD
• Application Number:
  US11/493,223
• Publication Number:
  US 20070030221A1
• Time in Patent Office: 1,350 Days
• Field of Search: None
• US Class Current: 349/38
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/13392 spacers dispersed on the cell substrate, e.g. spherical particles, microfibres
• CPC Class Codes: G02F 1/13398 Spacer materials; Spacer properties
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A liquid crystal display is provided. The liquid crystal display includes a first panel, a second panel facing and separated from the first panel, a liquid crystal layer interposed between the first and second panels, a plurality of variable capacitors that vary capacitance thereof by pressure, and a plurality of reference capacitors formed on the second panel and connected to the variable capacitors.

Claims

1. A liquid crystal display comprising:

a first panel;

a second panel facing and separated from the first panel;

a plurality of sensor scanning lines disposed on the second panel;

a plurality of sensor data lines formed on the second panel;

a liquid crystal layer interposed between the first and second panels;

a plurality of variable capacitors, whose capacitance thereof is varied by pressure; and

a plurality of reference capacitors formed on the second panel,

wherein a first electrode of each variable capacitor is connected to a first electrode of a corresponding one of the reference capacitors and is directly connected to one of the sensor data lines,

a second electrode of the corresponding one of the reference capacitors is connected to one of the sensor scanning lines, and

a touch position is detected by sensing a voltage of the first electrode of each variable capacitor.

2. The liquid crystal display of claim 1, wherein the first panel comprises a common electrode, and a second electrode of each variable capacitor is connected to the common electrode.

3. The liquid crystal display of claim 2, wherein the distance between the first and second electrodes of each variable capacitor is varied by pressure on the first panel, and the capacitances of the variable capacitors are varied based on variation of the distance.

4. The liquid crystal display of claim 2, wherein the second electrode of each variable capacitor is supplied with a predetermined voltage that swings between two different magnitudes thereof.

5. The liquid crystal display of claim 1, further comprising a plurality of switching circuits, each switching circuit being connected to one of the sensor data lines and charging the first electrode of each variable capacitor with predetermined voltages.

6. The liquid crystal display of claim 1, further comprising:

a plurality of image scanning lines formed on the second panel;

a plurality of image data lines intersecting the image scanning lines; and

a plurality of pixels connected to the image scanning lines and the image data lines.

7. The liquid crystal display of claim 6, wherein the image scanning lines are used as the sensor scanning lines.

22. The liquid crystal display of claim 1, wherein the second electrode of the corresponding one of the reference capacitors is directly connected to the one of the sensor scanning lines.

8. A liquid crystal display comprising:

a plurality of image scanning lines;

a plurality of image data lines intersecting the image scanning lines;

a plurality of sensor data lines intersecting the image scanning lines;

a plurality of sensor scanning lines intersecting the sensor data lines;

a plurality of pixels connected to the image scanning lines and the image data lines; and

a plurality of sensing units connected to the sensor data lines,

wherein the pixels comprise liquid crystal capacitors and switching elements connected to the liquid crystal capacitors, one of the image scanning lines, and one of the image data lines, respectively,

wherein the sensing units comprise;

variable capacitors having capacitance which varies based on pressure; and

reference capacitors,

wherein a sensing electrode of each variable capacitor is connected to a first electrode of a corresponding one of the reference capacitors and one of the sensor data lines,

a second electrode of the corresponding one of the reference capacitors is connected to one of the sensor scanning lines, and

the sensing unit detects a touch position by sensing a voltage of the sensing electrode of each variable capacitor.

9. The liquid crystal display of claim 8, wherein a common electrode is connected to an electrode of each variable capacitor different from the sensing electrode, and

a liquid crystal dielectric is interposed between the electrode of each variable capacitor different from the sensing electrode.

10. The liquid crystal display of claim 8, wherein the liquid crystal capacitor comprises a pixel electrode, a common electrode facing the pixel electrode, and a liquid crystal dielectric interposed between the pixel electrode and the common electrode.

11. The liquid crystal display of claim 8, further comprising:

an image scanning driver for applying image scanning signals to the image scanning lines;

an image data driver for applying image data signals to the image data lines;

a sensing signal processor for processing sensing signals from the sensor data lines; and

a signal controller for controlling the image scanning driver, the image data driver, and the sensing signal processor.

12. The liquid crystal display of claim 8, wherein the image scanning lines are used as the sensor data lines.

13. The liquid crystal display of claim 8, further comprising:

an image scanning driver for applying image scanning signals to the image scanning lines;

an image data driver for applying image data signals to the image data lines;

a sensor scanning driver for applying sensor scanning signals to the sensor scanning lines;

a sensing signal processor for processing sensing signals from the sensor data lines; and

a signal controller for controlling the image scanning driver, the image data driver, the sensor scanning driver, and the sensing signal processor.

14. A liquid crystal display comprising:

a first panel comprising a common electrode;

a second panel facing and separated from the first panel;

an image scanning line formed on the second panel;

an image data line formed on the second panel and intersecting the image scanning line;

a thin film transistor connected to the image scanning line and the image data line;

a pixel electrode connected to the thin film transistor and facing the common electrode;

a sensor data line formed on the second panel, extending in parallel to the image data line, and facing the common electrode;

a sensor scanning line disposed on the second panel;

a reference electrode formed on the second panel wherein the reference electrode extends from the sensor scanning line and overlaps a part of the sensor data line and a reference capacitor is formed by the reference electrode and the part of the sensor data line; and

a liquid crystal layer interposed between the first and second panel;

wherein a voltage of the sensor data line is varied by a variance of capacitance formed by the common electrode, the sensor data line and the liquid crystal layer,

the capacitance varies according to pressure on the first panel, and

touch positions are detected by the voltage of the sensor data line.

15. The liquid crystal display of claim 14, wherein the image scanning line is used as the sensor scanning line.

16. The liquid crystal display of claim 14, wherein the sensor data line is formed on the same layer as the image data line.

17. The liquid crystal display of claim 14, wherein the sensor data line is formed on the same layer as the pixel electrode.

18. The liquid crystal display of claim 14, wherein the pixel electrode comprises a transmissive electrode and a reflective electrode, and the sensor data line is formed on the same layer as one of the transmissive electrode and the reflective electrode.

19. The liquid crystal display of claim 14, further comprising a spacer disposed between the first and second panels, the spacer supporting the first and second panels and forming a predetermined gap therebetween.

20. The liquid crystal display of claim 14, further comprising an insulator disposed between the reference electrode and the part of the sensor data line.

21. The liquid crystal display of claim 20, wherein the reference capacitor is formed by the reference electrode, the insulating layer and the part of the sensor data line.