Liquid crystal display having particular reflective area and transmissive area

• US 7,486,361 B2
• Filed: 05/24/2007
• Issued: 02/03/2009
• Est. Priority Date: 12/09/2003
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation, Fujitsu Limited
• Inventors: Shibasaki, Masakazu, Tashiro, Kunihiro, Ueda, Kazuya, Tasaka, Yasutoshi, Ohmuro, Katsufumi, Yoshida, Hidefumi, Kamada, Tsuyoshi
• Primary Examiner(s): QI, ZHI QIANG
• Application Number:
  US11/805,831
• Publication Number:
  US 20070273813A1
• Time in Patent Office: 621 Days
• Field of Search: 349/114, 349/144, 349/146
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/133707 Structures for producing distorted electric fields, e.g. bumps, protrusions, recesses, slits in pixel electrodes

Abstract

The invention relates to a transflective liquid crystal display capable of display in both of transmissive and reflective modes and a method of manufacturing the same and provides a transflective liquid crystal display which can achieve high display characteristics in both of the transmissive and reflective modes. A configuration is employed which includes a liquid crystal display panel having a pair of substrates and a liquid crystal layer sealed between the substrates, a pixel region including a reflective area having a reflector for reflecting light entering from the side of one of the pair of substrates and a transmissive area for transmitting light entering from the side of the other of the pair of substrates toward the one of the pair of substrates, a backlight unit having a reflector and a light guide plate for reflecting the light which has entered the transmissive area from the side of the one of the pair of substrates and which has been transmitted by the area to cause the light to enter the transmissive area again from the side of the other of the pair of substrates, and a color filter layer formed only in the transmissive area of the pixel region.

Claims

1. A liquid crystal display comprising:

a pair of substrates opposite to each other;

a liquid crystal layer sealed between the pair of substrates; and

a pixel region having a reflective area including a reflector for reflecting light entering from the side of one of the pair of substrates, the reflector being provided on the other of the pair of substrates, and a transmissive area for transmitting light entering from the side of the other of the pair of substrates toward the one of the pair of substrates,

wherein the reflector is provided at the periphery of the pixel region;

wherein the transmissive area has a transparent pixel electrode which is provided at an opening of the reflector and which is formed above the reflector and electrically isolated from the reflector; and

wherein a cell thickness of the reflective area is substantially equal to or greater than a cell thickness of the transmissive area.

2. A liquid crystal display according to claim 1, wherein the reflector is provided on a bus line formed on the other of the pair of substrates.

3. A liquid crystal display according to claim 1, wherein the reflector is in an electrically floating state.

4. A liquid crystal display according to claim 1, wherein the reflector is at the same potential as that of a common electrode formed on either of the pair of substrates.

5. A liquid crystal display according to claim 1, wherein the reflector is at a ground potential.

6. A liquid crystal display according to claim 1, wherein the reflector is formed such that it is continuous between adjoining pixel regions.

7. A liquid crystal display according to claim 1, wherein the reflector is split between adjoining pixel regions.

8. A liquid crystal display according to claim 1, wherein the pixel electrode partially overlaps the reflector when viewed perpendicularly to a substrate surface.

9. A liquid crystal display according to claim 1, wherein an edge of the pixel electrode is aligned with an edge of the opening of the reflector when viewed perpendicularly to the substrate surface.

10. A liquid crystal display according to claim 1, wherein the edge of the pixel electrode is located inside the edge of the opening of the reflector when viewed perpendicularly to the substrate surface.

11. A liquid crystal display according to claim 1, wherein the edge of the pixel electrode is located outside the edge of the opening of the reflector when viewed perpendicularly to the substrate surface.

12. A liquid crystal display according to claim 1, wherein the pixel electrode includes a plurality of electrode units which are provided adjacent to each other with slits interposed between them and which are electrically connected to each other.

13. A liquid crystal display according to claim 12, wherein the reflector is further formed on the slits.

14. A liquid crystal display according to claim 12, wherein each of the electrode units has a solid electrode provided in a part of the electrode unit, and comb-shaped electrodes including a plurality of linear electrodes extending from the periphery of the solid electrode toward the periphery of the electrode unit.

15. A liquid crystal display according to claim 14, wherein the solid electrode is formed in the transmissive area.

16. A liquid crystal display according to claim 14, wherein the comb-shaped electrodes are formed such that they extend into the reflective area.

17. A liquid crystal display according to claim 16, wherein the comb-shaped electrodes in the reflective area include a smaller number of linear electrodes than the comb-shaped electrodes in the transmissive area.

18. A liquid crystal display according to claim 16, wherein each of gaps between adjoining comb-shaped electrodes formed by the comb-shaped electrodes in the reflective area is greater than each of gaps between adjoining comb-shaped electrodes formed by the comb-shaped electrodes in the transmissive area.

19. A liquid crystal display according to claim 12, wherein each of the electrode units has comb-shaped electrodes including a plurality of linear electrodes extending from a central section of the electrode unit toward the periphery of the electrode unit.

20. A liquid crystal display according to claim 19, wherein each of gaps between adjoining comb-shaped electrodes formed by the comb-shaped electrodes in the reflective area of the electrode unit is greater than each of gaps between adjoining comb-shaped electrodes formed by the comb-shaped electrodes in the transmissive area.

21. A liquid crystal display according to claim 19, wherein the comb-shaped electrodes in the reflective area of the electrode unit include a smaller number of linear electrodes than the comb-shaped electrodes in the transmissive area.

22. A liquid crystal display according to claim 12, wherein either of the pair of substrates has a protrusion for controlling alignment in a region associated with the central section of the electrode unit.

23. A liquid crystal display according to claim 1, further comprising a color filter layer formed under the reflector.

24. A liquid crystal display according to claim 23, further comprising a second color filter layer formed on either of the pair of substrates.

25. A liquid crystal display according to claim 23, further comprising a second color filter layer formed above the reflector.

26. A liquid crystal display according to claim 1, further comprising a color filter layer formed on either of the pair of substrates, wherein the color filter layer is removed in the reflective area.

27. A liquid crystal display according to claim 26, wherein the reflective area has a transparent resin layer having a thickness substantially equal to or smaller than the thickness of the color filter layer.

28. A liquid crystal display according to claim 1, comprising a pair of ¼

wave plates and a pair of polarizers provided outside the pair of substrates, respectively.

29. A liquid crystal display according to claim 1, comprising a light scattering layer formed outside either of the pair of substrates.

30. A liquid crystal display according to claim 29, wherein the light scattering layer is a film which scatters light entering in a predetermined direction.