Liquid crystal display device including image sensor and method of driving the same

• US 20080158120A1
• Filed: 05/11/2007
• Published: 07/03/2008
• Est. Priority Date: 12/29/2006
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Jo, Yong-Won, An, Cheung-Hwan
• Granted Patent: US 8,519,943 B2
• Time in Patent Office: Days
• US Class Current: 345/88
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence
• CPC Class Codes: H01L 27/14645 Colour imagers
• CPC Class Codes: H01L 27/14678 Contact-type imagers
• CPC Class Codes: H01L 27/14689 MOS based technologies
• CPC Class Codes: H01L 31/125 Composite devices with photosensitive elements and electroluminescent elements within one single body

Abstract

A liquid crystal display device includes a first data line and a second data line, the first and second data lines substantially parallel to one another, a first gate line, the first gate line crossing the first data line and the second data line, a display sub-pixel defined by the crossing of the first gate line and the first data line, a sensing sub-pixel defined by the crossing of the first gate line and the second data line, and a first switching element for connecting the second data line connected to one of a sensing processing unit and a ground terminal, wherein the display sub-pixel transmits light supplied from a light source in accordance to a data signal applied to the first data line, and the sensing sub-pixel senses light incident on the liquid crystal display device and generates charges corresponding to the sensed light.

Claims

1. A liquid crystal display device, comprising:

a first data line and a second data line, the first and second data lines substantially parallel to one another;

a first gate line, the first gate line crossing the first data line and the second data line;

a display sub-pixel defined by the crossing of the first gate line and the first data line;

a sensing sub-pixel defined by the crossing of the first gate line and the second data line; and

a first switching element for connecting the second data line to one of a sensing processing unit and a ground terminal,

wherein the display sub-pixel transmits light supplied from a light source in accordance to a data signal applied to the first data line, and

the sensing sub-pixel senses light incident on the liquid crystal display device and generates charges corresponding to the sensed light.

2. The device according to claim 1, wherein the display sub-pixel includes a second switching element connected to the first gate line and the first data line.

3. The device according to claim 1, wherein the sensing sub-pixel includes a third switching element for sensing the incident light and a fourth switching element for selectively applying the charges to the second data line.

4. The device according to claim 3, wherein the third switching element is connected to a common line and a power line, and the fourth switching element is connected to the second data line and one of the first gate line and a next gate line.

5. A liquid crystal display device, comprising:

a plurality of first sub-pixels, the first sub-pixels activated to display an image by selectively transmitting light irradiated from a rear side of the device; and

a plurality of second sub-pixels, the second sub-pixels selectively activated to sense one color light irradiated onto a front side of the device;

wherein the first sub-pixels and the second sub-pixels locate alternatively with one another.

6. The device according to claim 5, wherein the first sub-pixels include a first color display sub-pixel, a second color display sub-pixel and a third color display sub-pixel, the first, second and third color display sub-pixels sequentially driven.

7. The device according to claim 5, wherein the second sub-pixels include a first color sensing sub-pixel, a second color sensing sub-pixel and a third color sensing sub-pixel, the first, second and third color sensing sub-pixels sequentially generating intensity signals.

8. The device according to claim 7, further comprising:

a sensing processing unit, the sensing processing unit selectively connected to receive the intensity signals from one of the first, second and third color sensing sub-pixels.

9. The device according to claim 5, further comprising:

a plurality of gate lines, first data lines, second data lines, power lines and common lines, the gate lines crossing the first data lines to define the plurality of first sub-pixels, the gate lines crossing the second data lines to define the plurality of second sub-pixels.

10. A method of driving a liquid crystal display device comprising:

in a display mode, sequentially activating a first color display sub-pixel, a second color display sub-pixel and a third color display sub-pixel; and

in a sensing mode,

during a first sub-period, activating a first color sensing sub-pixel;

during a second sub-period, activating a second color sensing sub-pixel; and

during a third sub-period, activating a third color sensing sub-pixel.

11. The method according to claim 10, wherein

the color display sub-pixels include a red color display sub-pixel, a green display sub-pixel and a blue display sub-pixel,

the color sensing sub-pixels include a red color sensing sub-pixel, a green sensing sub-pixel and a blue sensing sub-pixel, and

in the sensing mode, activating the color sensing sub-pixels includes:

supplying a gate signal of a high level voltage to an n^th gate line to turn on at least three first switching elements and at least three second switching elements connected to the n^th gate line;

sequentially supplying a first display data signal to one of the red, green and blue display sub-pixels through one of a red display data line, a green display data line and a blue display data line; and

reading a sensing data signal in the red, green and blue sensing sub-pixels through a red sensing data line, a green sensing data line and a blue sensing data line, respectively.

12. The method according to claim 11, further comprising:

in the sensing mode, supplying a second display data signal to two of the red, green and blue display sub-pixels through two of the red, green and blue display data lines, the second display data signal having a voltage lower than the first display data signal and each of the red, green and blue display sub-pixels receiving one of the first and second display data signals at a time period.

13. The method according to claim 12, wherein the first and second display data signals respectively correspond to maximum and minimum transmittances of each of the red, green and blue display sub-pixels.

14. The method according to claim 11, wherein the reading the sensing data signal includes transmitting the sensing data signal in one of the red, green and blue sensing sub-pixels to a sensing processing unit through one of the red sensing data line, the green sensing data line and the blue sensing data line.

15. The method according to claim 10, wherein

the color display sub-pixels include a red color display sub-pixel, a green display sub-pixel and a blue display sub-pixel,

the color sensing sub-pixels include a red color sensing sub-pixel, a green sensing sub-pixel and a blue sensing sub-pixel, and

in the sensing mode, activating the color sensing sub-pixels includes:

supplying a gate signal of a high level voltage to an n^th gate line to turn on at least three first switching elements connected to the n^th gate line;

supplying the gate signal of a high level voltage to an (n+1)^th gate line to turn on at least three second switching elements connected to the (n+1)^th gate line;

sequentially supplying a first display data signal to the red, green and blue display sub-pixels through a red display data line, a green display data line and a blue display data line, respectively; and

reading a sensing data signal in the red, green and blue sensing sub-pixels through a red sensing data line, a green sensing data line and a blue sensing data line, respectively.

16. The method according to claim 15, further comprising:

in the sensing mode, supplying a second display data signal to two of the red, green and blue display sub-pixels through two of the red, green and blue display data lines, the second display data signal having a voltage lower than the first display data signal and each of the red, green and blue display sub-pixels receiving one of the first and second display data signals at a time period.

17. The method according to claim 16, wherein the first and second display data signals respectively correspond to maximum and minimum transmittances of each of the red, green and blue display sub-pixels.

18. The method according to claim 15, wherein the reading the sensing data signal includes transmitting the sensing data signal in one of the red, green and blue sensing sub-pixels to a sensing processing unit through one of the red sensing data line, the green sensing data line and the blue sensing data line.

19. The method according to claim 10, further comprising:

during the first sub-period, resetting the second color sensing sub-pixel and the third color sensing sub-pixel;

during the second sub-period, resetting the first color sensing sub-pixel and the third color sensing sub-pixel; and

during the third sub-period, resetting the first color sensing sub-pixel and the second color sensing sub-pixel.

20. The method according to claim 10, wherein the resetting the sensing sub-pixels includes grounding charges generated at the sensing sub-pixels.

21. A method of driving a liquid crystal display device having first, second and third pixels, each of the first, second and third pixels having a display sub-pixel and a sensing sub-pixel, comprising:

transmitting a first light through the display sub-pixel and sensing a second light in the sensing sub-pixel of one of the first, second and third pixels; and

shielding the first light in the display sub-pixels of the other two of the first, second and third pixels.

22. The method according to claim 21, wherein the transmitting and shielding the first light are repeated to sequentially transmit the first light through the display sub-pixel of each one of the first, second and third pixels.

23. The method according to claim 21, further comprising:

while sensing the second light, sensing a third light in the sensing sub-pixels of the other two of the first, second and third pixels, and resetting a sensing data signal corresponding to the third light in the other two of the first, second and third pixels.