Reflection-type liquid crystal display device having partition wall between liquid crystal layers and light scattering layer

• US 6,717,640 B2
• Filed: 08/22/2002
• Issued: 04/06/2004
• Est. Priority Date: 08/22/2001
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Sato, Eiji, Teranishi, Tomoko, Itoh, Yasuhisa, Minoura, Kiyoshi
• Primary Examiner(s): Dudek, James
• Assistant Examiner(s): SCHECHTER, ANDREW M
• Application Number:
  US10/225,466
• Publication Number:
  US 20030043334A1
• Time in Patent Office: 593 Days
• Field of Search: 349/74-80, 349/112, 349/115
• US Class Current: 349/112
• CPC Class Codes: G02F 1/13473 for wavelength filtering or for colour display without the use of colour mosaic filters
• CPC Class Codes: G02F 1/13478 based on selective reflection
• CPC Class Codes: G02F 1/13718 based on a change of the texture state of a cholesteric liquid crystal
• CPC Class Codes: G09G 2300/0486 Cholesteric liquid crystals, including chiral-nematic liquid crystals, with transitions between focal conic, planar, and homeotropic states

Abstract

The reflection-type liquid crystal display device includes two liquid crystal layers for selectively reflecting light in a specific wavelength range, and a partition wall interposed between the liquid crystal layers so as to separate the liquid crystal layers from each other. The partition wall serves as a scattering layer having a light scattering function.

Claims

1. A reflection-type liquid crystal display device, comprising:

at least two liquid crystal layers for selectively reflecting light in a specific wavelength range; and

at least one partition wall interposed between the at least two liquid crystal layers so as to separate the liquid crystal layers from each other, wherein

any one of the partition wall, a part of the liquid crystal layer which contacts the partition wall, and a part of the liquid crystal layer which contacts an alignment layer laminated to the partition wall serves as a scattering layer having a light scattering function.

2. The reflection-type liquid crystal display device according to claim 1, wherein the scattering layer is formed by any one of the following methods (1) to (4):

(1) performing a vertical alignment process to the partition wall;

(2) performing no alignment process to the partition wall;

(3) forming a vertical alignment layer on the partition wall; and

(4) forming concaves and convexes at a surface of the partition wall.

3. The reflection-type liquid crystal display device according to claim 1, wherein a half value width of a selective reflection wavelength is 150 nm or more in a visible light range, and a 50% selective reflection wavelength includes a range of 450 nm to 600 nm.

4. The reflection-type liquid crystal display device according to claim 1, wherein the at least two liquid crystal layers are two or three liquid crystal layers, and the liquid crystal layers selectively reflect different specific wavelength ranges and have different threshold voltages.

5. The reflection-type liquid crystal display device according to claim 1, wherein a scattered light intensity I (θ

) of the scattering layer is distributed such that an average value of I (0°

) to I (10°

) is equal to or less than 500 times an average value of I (20°

) to I (30°

).

6. The reflection-type liquid crystal display device according to claim 1, wherein a scattered light intensity I (θ

) of the scattering layer is distributed such that an average value of I (0°

) to I (10°

) is equal to or less than 400 times an average value of I (20°

) to I (30°

).

7. The reflection-type liquid crystal display device according to claim 1, wherein a scattered light intensity I (θ

) of the scattering layer is distributed such that an average value of I (0°

) to I (10°

) is equal to or less than 200 times an average value of I (20°

) to I (30°

).

8. The reflection-type liquid crystal display device according to claim 1, wherein a scattered light intensity I (θ

) of the scattering layer is distributed such that an average value of I (0°

) to I (10°

) is equal to or less than 100 times an average value of I (20°

) to I (30°

).

9. The reflection-type liquid crystal display device according to claim 1, wherein a scattered light intensity I (θ

) of the scattering layer is distributed such that an average value of I (0°

) to I (10°

) is equal to or less than 50 times an average value of I (20°

) to I (30°

).

10. The reflection-type liquid crystal display device according to claim 1, wherein a scattered light intensity I (θ

) of the scattering layer is distributed such that an average value of I (0°

) to (10°

) is equal to or less than 30 times an average value of I (20°

) to I (30°

).

11. The reflection-type liquid crystal display device according to claim 1, wherein a scattered light intensity I (θ

) of the scattering layer is distributed such that an average value of I (0°

) to I (10°

) is equal to or less than 20 times an average value of I (20°

) to I (30°

).

12. The reflection-type liquid crystal display device according to claim 1, wherein a scattered light intensity I (θ

) of the scattering layer is distributed such that an average value of I (0°

) to I (10°

) is equal to or less than 10 times an average value of I (20°

) to I (30°

).

13. The reflection-type liquid crystal display device according to claim 1, wherein a scattered light intensity I (θ

) of the scattering layer is distributed such that an average value of I (0°

) to I (10°

) is equal to or less than 5 times an average value of I (20°

) to I (30°

).

14. The reflection-type liquid crystal display device according to claim 1, wherein the liquid crystal layers are chiral nematic liquid crystal layers or holographic polymer-dispersed liquid crystal layers.