Image display device having wide and narrow viewing angle modes and method of driving the same

• US 7,675,598 B2
• Filed: 12/26/2006
• Issued: 03/09/2010
• Est. Priority Date: 06/27/2006
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Hong, Hyung-Ki
• Primary Examiner(s): Nelms; David
• Assistant Examiner(s): NGUYEN, THANH NHAN P
• Application Number:
  US11/644,871
• Publication Number:
  US 20070296900A1
• Time in Patent Office: 1,169 Days
• Field of Search: 349/114, 349/110, 349/129
• US Class Current: 349/141
• CPC Class Codes: G02F 1/1323 Arrangements for providing a switchable viewing angle
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence

Abstract

An image display device includes a display panel, and a barrier including a plurality of transmissive portions and a plurality of blocking portions on the display panel, wherein the plurality of transmissive portions and the plurality of blocking portions are arranged in a matrix, wherein 3N^th rows and (3N−1)^th rows include the plurality of transmissive portions and the plurality of blocking portions, N being a positive integer, (3N−2)^th rows include the plurality of transmissive portions excluding the plurality of blocking portions, , and the transmissive and blocking portions are alternately arranged.

Claims

1. An image display device, comprising:

a display panel; and

a barrier including a plurality of transmissive portions and a plurality of blocking portions on the display panel, wherein the plurality of transmissive portions and the plurality of blocking portions are arranged in a matrix, wherein 3N^th rows and (3N−

1)^th rows include the plurality of transmissive portions and the plurality of blocking portions, N being a positive integer, (3N−

2)^th rows include the plurality of transmissive portions excluding the plurality of blocking portions, and the transmissive and blocking portions are alternately arranged.

2. The device according to claim 1, wherein the transmissive portions in the 3N^th row align with the blocking portions in the (3N−

1)^th row.

3. The device according to claim 1, wherein the display panel includes a plurality of image pixel units, wherein each of the plurality of image pixel units includes first to sixth sub-pixels, and each of the plurality of image pixel units includes two columns and three rows.

4. The device according to claim 3, wherein the first and second sub-pixels correspond to a first row of the image pixel unit, the third and fourth sub-pixels correspond to a second row of the image pixel unit, and the fifth and sixth sub-pixels correspond to a third row of the image pixel unit.

5. The device according to claim 4, wherein the barrier provides first and second viewing zones having different viewing angles, the first, second, fourth and fifth sub-pixels display a first image in the first viewing zone, and the first, second, third and sixth sub-pixels display a second image in the second viewing zone.

6. The device according to claim 5, wherein the first viewing zone corresponds to a central region of the display panel, and the second viewing zone corresponds to two side regions of the first viewing zone.

7. The device according to claim 6, wherein an image signal supplied into the third and sixth sub-pixels and an image signal supplied into the fourth and fifth sub-pixels are the same.

8. The device according to claim 6, wherein a first summation between a luminance of an image signal in the first sub-pixel and a luminance of an image signal in third sub-pixel adjacent to the first sub-pixel is same as a second summation between a luminance of an image signal in the second sub-pixel and a luminance of an image signal in the sixth sub-pixel adjacent to the second sub-pixel.

9. The device according to claim 8, wherein the first and second summations has substantially a half of a maximum luminance in each sub-pixel.

10. The device according to claim 3, wherein each blocking portion has a greater area than each image pixel.

11. The device according to claim 1, wherein the barrier includes first and second substrates, first and second polarizers, first and second electrodes and a liquid crystal layer, wherein the first and second substrates face each other, the first and second electrodes are disposed on outer surfaces of the first and second substrates, respectively, the first and second electrodes are disposed on inner surface of the first and second substrates, respectively, the liquid crystal layer is interposed between the first and second substrates, and the second electrode corresponds to one of the transmissive and blocking portions.

12. The device according to claim 1, wherein when the display panel includes a liquid crystal panel and a backlight assembly on a rear side of the liquid crystal panel, the barrier is disposed one of a front side of the liquid crystal panel and between the liquid crystal panel and the backlight assembly.

13. An image display device, comprising:

a display panel; and

a barrier including a first row, a second row and a third row, the first row being substantially transmissive, the second row having a plurality of first transmissive portions and first blocking portions, and the third row having a plurality of second transmissive portions and second blocking portions, the first transmissive portions and the first blocking portions respectively align with the second blocking portions and the second transmissive portions.

14. The device according to claim 13, wherein the first transmissive portions and the first blocking portions are alternatively arranged along the second row, and the second transmissive portions and the second blocking portions are alternatively arranged along the third row.

15. The device according to claim 13, wherein the barrier includes first and second substrates, first and second polarizers, first and second electrodes and a liquid crystal layer.

16. The device according to claim 13, wherein the display panel includes a plurality of image pixel units, wherein each of the plurality of image pixel units includes first to sixth sub-pixels, and each of the plurality of image pixel units includes two columns and three rows.

17. The device according to claim 16, wherein the first and second sub-pixels correspond to a first row of the image pixel unit, the third and fourth sub-pixels correspond to a second row of the image pixel unit, and the fifth and sixth sub-pixels correspond to a third row of the image pixel unit.

18. The device according to claim 16, wherein the barrier provides first and second viewing zones having different viewing angles, the first, second, fourth and fifth sub-pixels display a first image in the first viewing zone, and the first, second, third and sixth sub-pixels display a second image in the second viewing zone.

19. The device according to claim 18, wherein the first viewing zone corresponds to a central region of the display panel, and the second viewing zone corresponds to two side regions of the first viewing zone.

20. A method of driving an image display device including a plurality of image pixel units, which convertibly operates in wide and narrow viewing angle modes, each of a plurality of pixel units has first to sixth sub-pixels are arranged in a matrix of two columns and three rows, comprising:

when operating in the narrow viewing angle mode, supplying first to sixth image signals into the first to sixth sub-pixels, respectively, the third and sixth image signals different from the fourth and fifth image signals; and

when operating in the wide viewing angle mode, supplying the first to sixth image signals into the first to sixth sub-pixels, respectively, the third and sixth image signals being same as the fourth and fifth image signals.

21. The method according to claim 20, wherein the step of supplying the first to sixth image signals includes a step of falsifying the first and second image signals to produce the third and fourth image signals, respectively, wherein a first summation between a luminance of the first and third sub-pixels, which are adjacent to each other, is same as a second summation between a luminance of the second and sixth sub-pixels, which are adjacent to each other.

22. The method according to claim 21, wherein the first and second summations have a half of maximum a luminance in each image pixel.

23. The method according to claim 20, wherein at one gray level, the first and second sub-pixels have a first luminance and the third and fourth sub-pixels have a second luminance, and wherein the second luminance is greater than the first luminance.

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

determining first luminance of the first and second image signals using a first gamma signal curve; and

determining second luminance of the third and fourth image signals using a second gamma signal curve.

25. The method according to claim 24, wherein the second gamma signal curve has luminance C1/C2 times as much as the first gamma signal curve at the gray level, C1 corresponding to a contribution of each the first and second sub-pixel to a total luminance, and C2 corresponding to a contribution of each of the third and sixth sub-pixels to a total luminance.

26. The method according to claim 25, wherein the C1/C2 is proportion to A1/A2, wherein A1 corresponding to an area of each of the first and second sub-pixels that is visible through a barrier over the display panel, and A2 corresponding to an area of each of the third and sixth sub-pixels that is visible through the barrier over the display panel.