Optical modulating/display device and production method therefor and display apparatus mounting the optical modulating/displaying device thereon

• US 20050146897A1
• Filed: 03/13/2003
• Published: 07/07/2005
• Est. Priority Date: 03/14/2002
• Status: Abandoned Application

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Sumiyoshi, Ken, Mimura, Koji, Saitoh, Goroh, Matsusima, Jin, Yagi, Yoshie
• Application Number:
  US10/507,562
• Publication Number:
  US 20050146897A1
• Time in Patent Office: Days
• US Class Current: 362/623
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G02F 1/133616 Front illuminating devices

Abstract

The present invention relates to an optical modulating display device (200) such as a liquid crystal displaying device provided with a front-light type planar illuminating device.

The above front-light type planar illuminating device allows illuminating light to propagate inside a substrate (1), and is provided with a low refraction layer (3) being lower in refractive index than the substrate (1) and being in close contact with the inner surface of the substrate (1), and with reflection structure (11) on the outer surface of the substrate (1).

The optical modulating display device (200) provided with the above front-light type planar illuminating device can ensure a sufficient amount of guide light propagating inside the substrate (1) and reduce non-uniformity in display illumination.

And a display apparatus mounting the above optical modulating display device (200) thereon can be reduced in thickness and weight and provide a high quality display.

Claims

1. An optical modulating display device including a multilayer structure containing an optical modulating layer and a pair of first and second substrates sandwiching the multilayer structure:

wherein

at least the first substrate is constituted so that light propagates therein;

the multilayer structure is constituted so that a boundary surface between the first substrate and a low refraction layer causes total reflection of light entering into the boundary surface in an oblique direction by including the low refraction layer being lower in refractive index than the first substrate and being in direct contact with the first substrate; and

the optical modulating layer comprises a liquid crystal layer and the multilayer structure further includes a polarizing layer transmitting a specific polarized light between the low refraction layer and the liquid crystal layer.

2. An optical modulating display device as claimed in claim 1, wherein a refractive index (nL) of the low refraction layer and a refractive index (nl) of the first substrate meet a condition given by nL−

nl<

−

0.01.

4. An optical modulating display device as claimed in claim 1, further including a reflection structure for reflecting at a right angle, or nearly right angle, to the boundary surface at least a part of the light entering in an oblique direction from the first substrate at an opposite side to the low refraction layer with reference to the first substrate.

5. An optical modulating display device as claimed in claim 1, wherein the reflection structure comprises a layered structure having at least either of a plurality of protrusions and a plurality of grooves at an opposite side to the first substrate.

6. An optical modulating display device as claimed in claim 5, wherein at least either of the plurality of protrusions and the plurality of grooves exist in almost the same region as a displaying region of the optical modulating display device.

7. An optical modulating display device as claimed in claim 1, wherein the low refraction layer comprises a transparent material.

8. An optical modulating display device as claimed in claim 1, wherein the low refraction layer comprises SiO₂.

9. An optical modulating display device as claimed in claim 1, wherein the low refraction layer comprises MgF.

11. An optical modulating display device as claimed in claim 1, wherein the polarizing layer positioned between the low refraction layer and the liquid crystal layer comprises a plurality of color polarizing layers transmitting only specific polarized light of different specific wavelength band and being spatially arranged within each pixel region.

12. An optical modulating display device as claimed in claim 1, wherein at least one or more phase difference layer in addition to the polarizing layer are positioned between the low refraction layer and the liquid crystal layer.

13. An optical modulating display device as claimed in claim 1, wherein the polarizing layer comprises a plurality of color polarizing layers transmitting only specific polarized light of different specific wavelength band and being spatially arranged within each pixel region and the plurality of color polarizing layers and at least one or more phase difference layer are positioned between the low refraction layer and the liquid crystal layer.

14. An optical modulating display device as claimed in claim 1, wherein the multilayer structure includes a laminated body laminated with a color filter layer transmitting light of different specific wavelength band, the polarizing layer, and at least one or more phase difference layer in this order between the low refraction layer and the liquid crystal layer.

15. An optical modulating display device as claimed in claim 1, wherein a light source is arranged in the vicinity of first side end of the first substrate and the first side end is protruded outside compared with a side end of a second substrate.

16. An optical modulating display device as claimed in claim 1, wherein the multilayer structure further includes a seal member provided for attaching the pair of first and second substrates in a peripheral region of the liquid crystal layer included in the multilayer structure, and a light blocking layer adjusted so as to overlap with the seal member viewed from a direction perpendicular to the boundary surface.

17. An optical modulating display device as claimed in claim 1, wherein the multilayer structure further includes a seal member provided for attaching the pair of first and second substrates in a peripheral region of a laminated body laminated with a color filter layer transmitting light of different specific wavelength band and at least one or more phase difference layer in this order between the low refraction layer and the liquid crystal layer.

18. An optical modulating display device as claimed in claim 1, wherein a light source is provided in the vicinity of first side end of the first substrate and a liquid crystal inlet used when injecting a liquid crystal material between the pair of first and second substrates is provided on a side of the liquid crystal layer different from the first side end.

3. (canceled)

10. (canceled)

19. An optical modulating display device including a multilayer structure containing an optical modulating layer and an optical propagating region having a uniform refractive index and being constituted so that light propagates therein;

wherein

the multilayer structure is constituted so that a boundary surface between the optical propagating region and the low refraction layer causes total reflection of light entering into the boundary surface in an oblique direction by including a low refraction layer being lower in refractive index than the optical propagating region and being in direct contact with the optical propagating region; and

the optical modulating layer comprises a liquid crystal layer and the multilayer structure further includes a polarizing layer transmitting only specific polarized light between the low refraction layer and the liquid crystal layer.

20. An optical modulating display device as claimed in claim 19, wherein a refractive index (nL) of the low refraction layer and a refractive index (nl) of the optical propagating region meet a condition given by nL−

nl<

−

0.01.

21. An optical modulating display device as claimed in claim 19, further including a reflection structure for reflecting at a right angle, or nearly right angle, to the boundary surface at least a part of the light entering in an oblique direction from the optical propagating region at an opposite side to the low refraction layer with reference to the optical propagating region.

22. An optical modulating display device as claimed in claim 19, wherein the reflection structure comprises a layered structure having at least either of a plurality of protrusions or a plurality of grooves at an opposite side to the first substrate.

23. An optical modulating display device as claimed in claim 19, wherein the low refraction layer comprises a transparent material.

24. An optical modulating display device as claimed in claim 19, wherein the optical propagating region comprises a substrate constituted so that light propagates therein.

25. An optical modulating display device as claimed in claim 19, wherein the optical propagating region includes a substrate constituted so that light propagates therein and a thin film inserted between the substrate and the low refraction layer and being the same in refractive index as the substrate.

26. An liquid crystal displaying device including at least:

a first and second substrates forming a pair, wherein at least first substrate is constituted so that light propagates therein;

a light source provided in the vicinity of a first side end of the first substrate;

a multilayer structure sandwiched between the first and second substrates, which includes at least an optical modulating layer comprising a liquid crystal layer, a low refraction layer being lower in refractive index than the first substrate and being in direct contact with the first substrate, a color filter layer transmitting light of different specific wavelength band, a polarizing layer positioned between the liquid crystal layer and the low refraction layer and transmitting only specific polarized light, and at least one or more phase difference layer; and

a reflection structure for reflecting at a right angle, or nearly right angle, to the boundary surface at least a part of light entering in an oblique direction from the first substrate at an opposite side to the low refraction layer with reference to the first substrate;

wherein a boundary surface between the first substrate and the low refraction layer causes total reflection of light entering into the boundary surface in an oblique direction.

27. An liquid crystal displaying device as claimed in claim 26, wherein a refractive index (nL) of the low refraction layer and a refractive index (nl) of the first substrate meet a condition given by nL−

nl<

−

0.01.

28. A liquid crystal displaying device as claimed in claim 26, wherein the reflection structure comprises a layered structure having at least either of a plurality of protrusions or a plurality of grooves at an opposite side to the first substrate.

29. A liquid crystal displaying device as claimed in claim 28, wherein at least either of a plurality of protrusions and a plurality of grooves exist in almost the same region as a displaying region of the optical modulating display device.

30. A liquid crystal displaying device as claimed in claim 26, wherein the low refraction layer comprises a transparent material.

31. A liquid crystal displaying device as claimed in claim 26, wherein the low refraction layer comprises SiO₂.

32. A liquid crystal displaying device as claimed in claim 26, wherein the low refraction layer comprises MgF.

33. A liquid crystal displaying device as claimed in claim 26, wherein the first side end of the first substrate is protruded outside compared with a side end of second substrate.

34. A liquid crystal displaying device as claimed in claim 26, wherein the multilayer structure further includes a seal member provided for attaching the pair of first and second substrates in a peripheral region of a liquid crystal layer included in the multilayer structure and a light blocking layer adjusted so as to overlap with the seal member viewed from a direction perpendicular to the boundary surface.

35. A liquid crystal displaying device as claimed in claim 26, wherein the multilayer structure further includes a seal member provided for attaching the pair of first and second substrates in a peripheral region of the color filter layer, the phase difference layer, and the liquid crystal layer.

36. A liquid crystal displaying device as claimed in claim 26, wherein a liquid crystal inlet used when injecting liquid crystal material between the pair of first and second substrates is provided at a side of the liquid crystal layer different from the first side end.

37. A liquid crystal displaying device including at least:

a first and second substrates forming a pair, wherein at least first substrate is constituted so that light propagates therein;

a light source provided in the vicinity of first side end of the first substrate;

a multilayer structure sandwiched between the first and second substrates, which includes at least an optical modulating layer comprising a liquid crystal layer, a low refraction layer being lower in refractive index than the first substrate and further being in direct contact with the first substrate, a plurality of color polarizing layers transmitting only specific polarized light of different specific wavelength band, being spatially arranged within each pixel region and being positioned between the low refraction layer and the liquid crystal layer, and at least one or more phase difference layer; and

a reflection structure for reflecting at a right angle to, or nearly right angle to, the boundary surface at least a part of light entering in an oblique direction from the first substrate at an opposite side to the low refraction layer with reference to the first substrate;

wherein a boundary surface between the first substrate and the low refraction layer causes total reflection of light entering into the boundary surface in an oblique direction.

38. A liquid crystal displaying device as claimed in claim 37, wherein a refractive index (nL) of the low refraction layer and a refractive index (nl) of the first substrate meet a condition given by nL−

nl<

−

0.01.

39. A liquid crystal displaying device as claimed in claim 37, wherein the reflection structure comprises a layered structure having at least either of a plurality of protrusions and a plurality of grooves at an opposite side to the first substrate.

40. A liquid crystal displaying device as claimed in claim 39, wherein the plurality of protrusions and the plurality of grooves exist in almost the same region as a displaying region of the optical modulating display device.

41. A liquid crystal displaying device as claimed in claim 37, wherein the low refraction layer comprises a transparent material.

42. A liquid crystal displaying device as claimed in claim 37, wherein the low refraction layer comprises SiO₂.

43. A liquid crystal displaying device as claimed in claim 37, wherein the low refraction layer comprises MgF.

44. A liquid crystal displaying device as claimed in claim 37, wherein the first side end of the first substrate is protruded outside compared with a side end of a second substrate.

45. A liquid crystal displaying device as claimed in claim 37, wherein the multilayer structure further includes a seal member provided in a peripheral region included in the multilayer structure and a light blocking layer adjusted so as to overlap with the seal member viewed from a direction perpendicular to the boundary surface for attaching the pair of first and second substrates.

46. A liquid crystal displaying device as claimed in claim 37, wherein the multilayer structure further includes a seal member provided for attaching the pair of first and second substrates in a peripheral region of the plurality of color polarizing layers, the phase difference layer, and the liquid crystal layer.

47. A liquid crystal displaying device as claimed in claim 37, wherein a liquid crystal inlet used when injecting a liquid crystal material between the pair of first and second substrates is provided at a side of the liquid crystal layer different from the first side end.

48. An optical modulating display device including at least:

a first and second substrates forming a pair, wherein at least the first substrate is constituted so that light propagates therein;

a light source provided in the vicinity of first side end of the first substrate;

a multilayer structure sandwiched between the first and second substrates, which includes an optical modulating layer comprising a liquid crystal layer, a low refraction layer being lower in refractive index than the first substrate and further being in direct contact with the first substrate, a polarizing layer positioned between the low refraction layer and the liquid crystal layer and transmitting a specific polarized light, and a charged fine particle filled layer; and

a reflection structure for reflecting at a right angle, or nearly right angle, to the boundary surface at least a part of light entering in an oblique direction from the first substrate at an opposite side to the low refraction layer with reference to the first substrate;

wherein a boundary surface between the first substrate and the low refraction layer causes total reflection of light entering into the boundary surface in an oblique direction.

49. An optical modulating display device as claimed in claim 48, wherein a refractive index (nL) of the low refraction layer and a refractive index (nl) of the first substrate meet a condition given by nL−

nl<

−

0.01.

50. An optical modulating display device as claimed in claim 48, wherein the reflection structure comprises a layered structure having at least either of a plurality of protrusions and a plurality of grooves at an opposite side to the first substrate.

51. An optical modulating display device as claimed in claim 50, wherein at least either of the plurality of protrusions and the plurality of grooves exist in almost the same region as a displaying region of the optical modulating display device.

52. An optical modulating display device as claimed in claim 48, wherein the low refraction layer comprises a transparent material.

53. An optical modulating display device as claimed in claim 48, wherein the low refraction layer comprises SiO₂.

54. An optical modulating display device as claimed in claim 48, wherein the low refraction layer comprises MgF.

55. A production method for an optical modulating display device, comprising the steps of:

manufacturing an optical modulating device including a multilayer structure sandwiched between a first substrate constituted so that light propagates therein and a second substrate forming a counterpart to the first substrate, wherein the multilayer structure includes an optical modulating layer comprising a liquid crystal layer, a low refraction layer being in contact with the first substrate and comprising a material being lower in refractive index than the first substrate, and a polarizing layer positioned between the low refraction layer and the liquid crystal layer and transmitting only specific polarized light; and

then, forming a reflection structure for reflecting at a right angle, or nearly right angle, to the boundary surface at least a part of light entering in an oblique direction from the first substrate at an opposite side to the low refraction layer with reference to the first substrate in the optical modulating device.

56. A production method for an optical modulating display device as claimed in claim 55, wherein the step of forming the reflection structure further comprises the steps of:

applying a UV curing transparent resin on an opposite side to the first substrate;

pressing a metal mold having at least either of a plurality of protrusions and a plurality of grooves on the UV curing transparent resin, while pressing, introducing ultraviolet ray into the first substrate from first side end of the first substrate, and hardening the UV curing transparent resin, thereby printing the shape of the metal mold on the UV curing transparent resin.

57. A production method of an optical modulating display device as claimed in claim 55, wherein the step of forming the reflection structure further comprises the steps of:

forming a transparent resin sheet at an opposite side of a first substrate;

pressing a metal mold having at least either of a plurality of protrusions or a plurality of grooves on the transparent resin and applying pressure thereon, and while applying the pressure thereon, heating the transparent resin sheet up to a temperature of a glass transition point or higher of the transparent resin sheet, followed by printing the shape of the metal mold on the transparent resin sheet;

while continuing to apply the pressure thereon, cooling down the transparent resin sheet up to room temperature; and

striping off the metal mold from the transparent resin sheet.

58. A production method of an optical modulating display device as claimed in claim 55, further comprising the steps of:

forming the reflection structure; and

thereafter, further dividing the optical modulating display device into a plurality of individual optical modulating display devices.

59. A production method of an optical modulating display device as claimed in claim 58, wherein the step of manufacturing the optical modulating device further comprises the steps of assembling the pair of first and second substrates and providing previously a score at a side where the optical modulating layer in at least one of the first and second substrates further exist before the step of assembling.

60. A production method of a liquid crystal displaying device comprising the steps of:

manufacturing a liquid crystal device including a first substrate constituted so that light propagates therein, a second substrate forming a counterpart to the first substrate, and a multilayer structure sandwiched between the first and second substrates which includes a liquid crystal layer, a low refraction layer being in contact with the first substrate and comprising a material being lower in refractive index than the first substrate, and a polarizing layer positioned between the low refraction layer and the liquid crystal layer and transmitting only specific polarized light; and

thereafter, forming a reflection structure for reflecting at a right angle, or nearly right angle, to the boundary surface at least a part of light entering in an oblique direction from the first substrate at an opposite side to the low refraction layer with reference to the first substrate in the liquid crystal device.

61. A production method of a liquid crystal displaying device as claimed in claim 60, wherein the step of forming the reflection structure further comprises the steps of:

applying UV curing transparent resin on an opposite side of the first substrate; and

pressing a metal mold having at least either of a plurality of protrusions and a plurality of grooves on the UV curing transparent resin, and while pressing, introducing ultraviolet ray from first side end of the first substrate into the first substrate, followed by hardening the UV curing transparent resin, thereby printing the shape of the metal mold on the UV curing transparent resin.

62. A production method of a liquid crystal displaying device as claimed in claim 60, wherein the step of forming the reflection structure further comprises the steps of:

forming a transparent resin sheet at an opposite side of the first substrate;

pressing a metal mold having at least either of a plurality of protrusions or a plurality of grooves on the transparent resin and applying pressure thereon, and while applying the pressure thereon, heating the transparent resin sheet up to a temperature of a glass transition point or higher of the transparent resin sheet, followed by printing the shape of the metal mold on the transparent resin sheet;

while continuing to apply the pressure thereon, cooling down the transparent resin sheet up to room temperature; and

striping off the metal mold from the transparent resin sheet.

63. A production method of a liquid crystal displaying device as claimed in claim 60, further including a step of dividing the liquid crystal displaying device into a plurality of individual liquid crystal displaying devices after a step of forming the reflection structure.

64. A production method of a liquid crystal displaying device as claimed in claim 63, wherein the step of manufacturing the liquid crystal device further includes a step of assembling the pair of first and second substrates, and a step of previously providing a score at a side in which the liquid crystal layer exists in at least one of the first and second substrates.