Liquid-crystal display device and method of fabricating the same

• US 6,924,856 B2
• Filed: 06/14/2002
• Issued: 08/02/2005
• Est. Priority Date: 06/14/2001
• Status: Expired due to Term

• Current Assignee: NLT Technologies, Ltd. (Tianma Microelectronics Company Limited)
• Original Assignee: NEC LCD Technologies Limited (Tianma Microelectronics Company Limited)
• Inventors: Okumura, Hiroshi, Suzuki, Masayoshi
• Primary Examiner(s): Ton, Toan
• Assistant Examiner(s): DUONG, TAI V
• Application Number:
  US10/172,261
• Publication Number:
  US 20020191128A1
• Time in Patent Office: 1,145 Days
• Field of Search: 349/57, 349/61, 349/64, 349/86, 349/95, 349/112, 349/117, 349/119, 349/143, 349/146, 349/155, 349/156, 349/177, 349/178
• US Class Current: 349/96
• CPC Class Codes: G02F 1/133526 Lenses, e.g. microlenses or Fresnel lenses
• CPC Class Codes: G02F 1/133638 Waveplates, i.e. plates with a retardation value of lambda/n
• CPC Class Codes: G02F 1/1393 the birefringence of the liquid crystal being electrically controlled, e.g. ECB-, DAP-, HAN-, PI-LC cells G02F1/1396, G02F1/141 take precedence

Abstract

A LCD device is provided. On the input side, the collimated-light generator generates collimated light from incident light and then, the first polarizer plate of the first polarized-light controller generates first polarized light from the collimated light. The first quarter wavelength plate of the first polarized-light controller generates second polarized light from the first polarized light. The second polarized light thus generated passes through the liquid crystal layer to reach the output side. On the output side, the second polarized light passes through the second quarter wavelength plate of the second polarized-light controller and the second quarter wavelength plate thereof. Thus, the polarization state of the second polarized light is returned to its original one.

Claims

1. A liquid crystal display device comprising:

(a) a first substrate located on an input side;

(b) a second substrate fixed to be opposite to the first substrate;

the second substrate being located on an output side;

(c) a liquid crystal layer interposed between the first substrate and the second substrate;

the liquid crystal layer containing a liquid crystal;

the liquid crystal layer and the first and second substrates constituting a liquid crystal section;

(d) a collimator for collimating its incident light;

the collimator being located on the input side;

(e) a first polarization controller for controlling polarization state of its incident light;

the first polarization controller being located on the input side;

the first polarization controller including a first polarizer member and a first quarter wavelength member;

(g) a second polarization controller for controlling polarization state of its incident light;

the second polarization controller being located on the output side;

the second polarization controller including a second polarizer member and a second quarter wavelength member;

wherein said collimator is located between said first nolarization controller and second polarization controller.

2. The device according to claim 1, further comprising a half wavelength plate located between the first or second polarizer member and the first or second substrate.

3. The device according to claim 1, wherein the collimator is a microlens array having microlenses arranged in a matrix array corresponding to respective pixels.

4. The device according to claim 3, wherein the microlens array is made of a material deformable by irradiation of laser light;

and wherein the array is united with a back of the first substrate.

5. The device according to claim 1, wherein the liquid crystal of the liquid crystal layer has negative anisotropy of dielectric constant;

and wherein molecules of the liquid crystal are orientated approximately perpendicular to the first substrate when no voltage is applied across the liquid crystal layer.

6. The device according to claim 5, wherein the liquid crystal has an optical anisotropy Δ

n and the liquid crystal layer has a thickness d;

and wherein product (Δ

n·

d) of the anisotropy Δ

n and the thickness d is in a range of 400 nm to 800 nm.

7. The device according to claim 1, wherein the liquid crystal of the liquid crystal layer has positive anisotropy of dielectric constant;

and wherein molecules of the liquid crystal are aligned to have a homogeneous structure when no voltage is applied across the liquid crystal layer.

8. The device according to claim 1, wherein the first substrate has scan signal electrodes, data electrodes, and pixel electrodes;

and wherein the second substrate has a counter electrode opposite to the pixel electrodes.

9. The device according to claim 8, wherein each of the electrodes on the first substrate has a symmetrical shape;

and wherein the counter electrode on the second substrate covers entirely the electrodes on the first substrate, and is wider than the electrodes on the first substrate.

10. The device according to claim 8, wherein each of the electrodes on the first substrate has a series of symmetrical shapes.

11. The device according to claim 9, wherein each of the electrodes on the first substrate has a depression at a position corresponding to a symmetrical axis.

12. The device according to claim 9, wherein each of the electrodes on the first substrate has a columnar spacer at a position corresponding to a symmetrical center.

13. The device according to claim 9, wherein the electrode on the second substrate has a structure including protrusions formed entirely or partially at positions overlapped with symmetrical axes of the electrodes on the first substrate when observed along a normal of the first substrate.

14. The device according to claim 9, wherein the electrode on the second substrate has a structure including openings formed entirely or partially at positions overlapped with symmetrical axes of the electrodes on the first substrate when observed along a normal of the first substrate.

15. The device according to claim 1, wherein the device operates in a vertical alignment mode.

16. A liquid crystal display device comprising:

(a) a first substrate located on an input side;

(b) a second substrate fixed to be opposite to the first substrate;

the second substrate being located on an output side;

(c) a liquid crystal layer interposed between the first substrate and the second substrate;

the liquid crystal layer containing a liquid crystal;

the liquid crystal layer and the first and second substrates constituting a liquid crystal section;

(d) a collimator for collimating its incident light;

the collimator being located on the input side;

(e) a first polarization controller for controlling polarization state of its incident light;

the first polarization controller being located on the input side;

the first polarization controller including a first polarizer plate and a first quarter wavelength plate;

(g) a second polarization controller for controlling polarization state of its incident light;

the second polarization controller being located on the output side;

the second polarization controller including a second polarizer plate and a second quarter wavelength plate; and

(h) a viewing-angle controller member located on the output side

wherein said collimator is located between said first polarization controller and said second polarization controller.

17. The device according to claim 16, wherein the viewing-angle controller member includes a polymer-dispersed liquid crystal layer;

and wherein a transmittance of the polymer-dispersed liquid crystal layer is changed by a voltage applied across the polymer-dispersed liquid crystal layer, thereby adjusting viewing angle.

18. The device according to claim 16, further comprising a half wavelength plate located between the first polarizer plate and the first substrate.

19. The device according to claim 16, wherein the collimator is a microlens array having microlenses arranged in a matrix array corresponding to respective pixels.

20. The device according to claim 19, wherein the microlens array is made of a material deformable by irradiation of laser light;

and wherein the array is united with a back of the first substrate.

21. The device according to claim 16, wherein the liquid crystal of the liquid crystal layer has negative anisotropy of dielectric constant;

and wherein molecules of the liquid crystal are orientated approximately perpendicular to the first substrate when no voltage is applied across the liquid crystal layer.

22. The device according to claim 21, wherein the liquid crystal has an optical anisotropy Δ

n and the liquid crystal layer has a thickness d;

and wherein product (Δ

n·

d) of the anisotropy Δ

n and the thickness d is in a range of 400 nm to 800 nm.

23. The device according to claim 16, wherein the liquid crystal of the liquid crystal layer has positive anisotropy of dielectric constant;

and wherein molecules of the liquid crystal are aligned to have a homogeneous structure when no voltage is applied across the liquid crystal layer.

24. The device according to claim 16, wherein the first substrate has scan signal electrodes, image signal electrodes, and pixel electrodes;

and wherein the second substrate has a counter electrode opposite to the pixel electrodes.

25. The device according to claim 24, wherein each of the electrodes on the first substrate has a symmetrical shape;

and wherein the counter electrode on the second substrate covers entirely the electrodes on the first substrate, and is wider than the electrodes on the first substrate.

26. The device according to claim 24, wherein each of the electrodes on the first substrate has a series of symmetrical shapes.

27. The device according to claim 25, wherein each of the electrodes on the first substrate has a depression at a position corresponding to a symmetrical axis.

28. The device according to claim 25, wherein each of the electrodes on the first substrate has a columnar spacer at a position corresponding to a symmetrical center.

29. The device according to claim 25, wherein the electrode on the second substrate has a structure including protrusions formed entirely or partially at positions overlapped with symmetrical axes of the electrodes on the first substrate when observed along a normal of the first substrate.

30. The device according to claim 25, wherein the electrode on the second substrate has a structure including openings formed entirely or partially at positions overlapped with symmetrical axes of the electrodes on the first substrate when observed along a normal of the first substrate.

31. The device according to claim 16, wherein the device operates in a vertical alignment mode.

32. A liquid crystal display device comprising:

(a) a first substrate located on an input side;

(b) a second substrate fixed to be opposite to the first substrate;

the second substrate being located on an output side;

(c) a liquid crystal layer interposed between the first substrate and the second substrate;

the liquid crystal layer containing a liquid crystal;

the liquid crystal layer and the first and second substrates constituting a liquid crystal

(d) a collimator for collimating its incident light;

the collimator being located on the input side;

(e) a first polarization controller for controlling polarization state of its incident light;

the first polarization controller being located on the input side;

the first polarization controller including a first polarizer elate and a first quarter wavelength plate;

(g) a second polarization controller for controlling polarization state of its incident light;

the second polarization controller being located on the output side;

the second polarization controller including a second polarizer plate and a second quarter wavelength plate; and

(h) a viewing-angle controller member located on the output side wherein the viewing-angle controller member is detachable;

and wherein viewing angle is adjustable by replacing the viewing-angle controller member with another one.