Display device and driving method thereof

• US 20050151711A1
• Filed: 06/28/2004
• Published: 07/14/2005
• Est. Priority Date: 12/30/2003
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Baek, Heum-II
• Granted Patent: US 7,554,565 B2
• Time in Patent Office: Days
• US Class Current: 345/88
• CPC Class Codes: G09G 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A display device includes an image attribute signal generating portion analyzing R, G, and B input data signals with first brightness levels and generating attribute signals; a signal treating portion converting the R, G, and B input data signals to R, G, and B output data signals using the plurality of attribute signals, wherein R, G, and B input data signals used to display images having colors other than white are converted to R, G, and B output data signals, wherein the R. G, and B output data signals have second brightness levels, wherein the second brightness levels are lower than the first brightness levels; and a display portion having a plurality of pixels, wherein each pixel includes R, G, and B sub-pixels, and wherein the R, G, and B output data signals are supplied to respective ones of the R, G, and B sub-pixels.

Claims

1. A display device, comprising:

an image attribute signal generating portion analyzing red (R), green (G), and blue (B) input data signals and generating a plurality of attribute signals;

a signal treating portion connected to the image attribute signal generating portion, the signal treating portion converting the R, G, and B input data signals to R, G, and B output data signals using the plurality of attribute signals, wherein the R, G, and B input data signals have first brightness levels, wherein R, G, and B input data signals used to display images having colors other than white are converted to R, G, and B output data signals, wherein the R, G, and B output data signals have second brightness levels, wherein the second brightness levels are lower than the first brightness levels; and

a display portion having a plurality of pixels, wherein each pixel includes R, G, and B sub-pixels, and wherein the R, G, and B output data signals are supplied to respective ones of the R, G, and B sub-pixels.

2. The display device according to claim 1, wherein the image attribute signal generating portion includes:

a MIN·

MAX extracting portion connected to the signal treating portion, the MIN·

MAX extracting portion extracting minimum and maximum signals from the R, G, and B input data signals;

an image attribute factor generating portion connected to the signal treating portion, the image attribute factor generating portion analyzing R, G, and B input data signals and generating an image attribute factor (α

), wherein 0≦

α

≦

1; and

an intermediate signal generation portion connected to the MIN-MAX extracting portion and the signal treating portion, the intermediate signal generation portion generating an intermediate signal (W) using the minimum signal.

3. The display device according to claim 2, wherein the signal treating portion converts the R, G, and B input data signals to the R, G, and B output data signals using the maximum signal, the image attribute factor, and the intermediate signal.

4. The display device according to claim 2, wherein the intermediate signal is generated in accordance with the expression W=MIN^k (where W is the intermediate signal, MIN is the minimum signal, and k is a real number).

5. The display device according to claim 3, wherein the signal treating portion converts the R, G, and B input data signals to the R, G, and B output data signals in accordance with the expression (Ro, Go, Bo)=((1−

α

)×

MAX+α

×

W)/MAX×

(Ri, Gi, Bi) (where Ro, Go, and Bo are the R, G, and B output data signals, respectively, Ri, Gi, and Bi are the R, G, and B input data signals, respectively, a is the image attribute factor, and MAX is the maximum signal).

6. The display device according to claim 1, further comprising:

a first signal region converting portion connected to the image attribute signal generating portion and the signal treating portion, the first signal region converting portion converting the R, G, and B input data signals in an L* signal region to the R, G, and B input data signals in a Y signal region; and

a second signal region converting portion connected to the signal treating portion, the second signal region converting portion converting the R, G, and B output data signals in the Y signal region to the R, G, and B output data signals in the L* signal region.

7. The display device according to claim 6, wherein

the first and second signal region converting portions each include first and second look-up tables, respectively;

the first look-up table includes pre-calculated values of the R, G, and B input data signals in the L* signal region and corresponding values of the R, G, and B input data signals in the Y signal region; and

the second look-up table includes pre-calculated values of the R, G, and B output data signals in the Y signal region and corresponding values of R, G, and B output data signals in the L* signal region.

8. The display device according to claim 1, further comprising a timing controlling portion outputting the R, G, and B output data signals to the display portion.

9. The display device according to claim 1, further comprising a light source supplying light to the display portion.

10. The display device according to claim 1, wherein the display device includes a liquid crystal display device.

11. A method of driving a display device, comprising:

analyzing red (R), green (G), and blue (B) input data signals and generating a plurality of attribute signals;

converting the R, G, and B input data signals to R, G, and B output data signals using the plurality of attribute signals, wherein the R, G, and B input data signals have first brightness levels, wherein R, G, and B input data signals used to display color images having colors other than white are converted to R, G, and B output data signals, wherein the R, G, and B output data signals have second brightness levels, wherein the second brightness levels are lower than the first brightness levels; and

displaying images via a plurality of pixels, wherein each pixel includes R, G, and B sub-pixels, and wherein the R, G, and B output data signals are supplied to respective ones of the R, G, and B sub-pixels.

12. The method of driving according to claim 11, wherein analyzing the R, G, and B input data signals and generating a plurality of attribute signals includes:

extracting minimum and maximum signals from the R, G, and B input data signals;

analyzing the R, G, and B input data signals and generating an image attribute factor(α

), wherein 0≦

α

≦

1; and

generating an intermediate signal (W) from the minimum signal.

13. The method of driving according to claim 12, wherein the R, G, and B input data signals are converted to the R, G, and B output data signals using the maximum signal, the image attribute factor, and the intermediate signal.

14. The method of driving according to claim 12, wherein the intermediate signal is generated in accordance with the expression W=MIN^k (where W is the intermediate signal, MIN is the minimum signal, and k is a real number).

15. The method of driving according to claim 13, wherein the R, G, and B input data signals are converted to the R, G, and B output data signals in accordance with the expression (Ro, Go, Bo)=((1−

α

)×

MAX+α

×

W)/MAX×

(Ri, Gi, Bi) (where Ro, Go, and Bo are the R, G, and B output data signals, respectively, Ri, Gi, and Bi are the R, G, and B input data signals, respectively, α

is the image attribute factor, and MAX is the maximum signal).

16. The method of driving according to claim 11, further comprising:

converting the R, G, and B input data signals from an L* signal region to R, G, and B input data signals in a Y signal region; and

converting the R, G, and B output data signals from a Y signal region to R, G, and B output data signals in an L* signal region.

17. The method of driving according to claim 11, further comprising outputting the R, G, and B output data signals to respective ones of R, G, and B sub-pixels according to a timing sequence.

18. The method of driving according to claim 11, further comprising supplying light to the plurality of sub-pixels.

19. The method of driving according to claim 11, wherein the display device includes a liquid crystal display device.