Display device with backlight

• US 20030206256A1
• Filed: 05/06/2002
• Published: 11/06/2003
• Est. Priority Date: 05/06/2002
• Status: Abandoned Application

• Current Assignee: Avery Dennison Corporation
• Original Assignee: Avery Dennison Corporation
• Inventors: Drain, Kieran F., Sasaki, Yukihiko
• Application Number:
  US10/139,456
• Publication Number:
  US 20030206256A1
• Time in Patent Office: Days
• US Class Current: 349/113
• CPC Class Codes: G02F 1/133507 Films for enhancing the luminance
• CPC Class Codes: G02F 1/133603 with LEDs

Abstract

A display device includes a light control device, and a backlight having a panel with one or more light management features. The light control device may be a liquid crystal display (LCD), for example having a plurality of picture elements, such as pixels, selectively activatable to allow or black transmission of light through the LCD. The light management features may include one or more features such as a brightness enhancement film, a transflective film, and/or a polarizing film. The backlight has a light emitting structure that may include an electroluminescent structure, such a small molecule organic light emitting device (SMOLED) or a polymer light emitting device (PLED). The electroluminescent structure of the backlight provides good illumination of the light control device at low voltage and low power, and the inclusion of the one or more light management features in the backlight may result in reduction of size, cost, and/or weight of the display device.

Claims

1. A display device comprising:

a light control device having a plurality of picture elements; and

a backlight coupled to the light control device, wherein the backlight includes;

a first panel that includes at least one light management feature;

a second panel sealingly adhered to the first panel; and

a light emitting structure between the first and second panels.

2. The display device of claim 1, wherein the light emitting structure is formed upon the second panel.

3. The display device of claim 1, wherein the light emitting structure is formed upon the first panel.

4. The display device of claim 1, wherein the at least one light management feature includes a brightness enhancement film.

5. The display device of claim 4, wherein the brightness enhancement film includes a plurality of prisms.

6. The display device of claim 5, wherein the prisms include two-dimensional bars with a triangular cross-section.

7. The display device of claim 5, wherein the prisms include pyramids.

8. The display device of claim 1, wherein the at least one light management feature includes a transflective film.

9. The display device of claim 1, wherein the at least one light management feature includes a polarizing film.

10. The display device of claim 1, wherein the at least one light management feature includes first and second light management features.

11. The display device of claim 10, wherein the first and second light management features are each selected from a group consisting of a brightness enhancement film, a reflective film, a transflective film, a polarizing film, and a light diffusing film.

12. The display device of claim 11, wherein the first and second light management features are different types of light management features.

13. The display device of claim 11, wherein the first and second light management features are the same of type of light management feature.

14. The display device of claim 13, wherein the first light management feature is a first brightness enhancement films, and wherein the second light management feature is a second brightness enhancement film.

15. The display device of claim 14, wherein the first brightness enhancement film has a cross-sectional shape different than a cross-sectional shape of the second brightness enhancement film.

16. The display device of claim 14, wherein the first brightness enhancement film has an orientation different than an orientation of the second brightness enhancement film.

17. The display device of claim 14, wherein the first brightness enhancement film has a protrusion size different than a protrusion size of the second brightness enhancement film.

18. The display device of claim 10, wherein the first and second light management features are on opposite respective sides of the first panel.

19. The display device of claim 1, wherein the light emitting structure includes an anode, a cathode, and a light emitting material between the anode and the cathode.

20. The display device of claim 19, wherein the light emitting material includes a polymer emitter.

21. The display device of claim 20, wherein the polymer emitter includes a blend of light emitting polymers.

22. The display device of claim 21, wherein the blend of light emitting polymers is a miscible blend of light emitting polymers.

23. The display device of claim 21, wherein the blend of light emitting polymers is an immiscible blend of light emitting polymers.

24. The display device of claim 21, wherein the blend of light emitting polymers collectively produces white light.

25. The display device of claim 19, wherein the light emitting material includes an organic emitter.

26. The display device of claim 19, wherein the light emitting material includes a monochrome emitter.

27. The display device of claim 19, wherein the light emitting material includes plural emitters, at least one of which emits different colored light than another of the emitters.

28. The display device of claim 27, wherein the plural emitters includes first, second, and third emitters.

29. The display device of claim 28, wherein the first emitter emits blue light, the second emitter emits red light, and the third emitter emits green light.

30. The display device of claim 27, wherein the plural light emitters are stacked one on top of another.

31. The display device of claim 27;

wherein the plural light emitters are arranged side by side.

32. The display device of claim 31, wherein the plural light emitters are arranged as alternating stripes of different of the light emitters.

33. The display device of claim 19, wherein the light emitting material includes a hole transport material.

34. The display device of claim 33, wherein the hole transport material has a thickness from 100 to 500 Angstroms.

35. The display device of claim 34, wherein the light emitting material further includes an electron transport material.

36. The display device of claim 35, wherein the electron transport material has a thickness from 100 to 500 Angstroms.

37. The display device of claim 33, wherein the light emitting material does not include an electron transport material.

38. The display device of claim 33, wherein the light emitting material further includes an emitter.

39. The display device of claim 37, wherein the emitter has a thickness from 50 to 100 Angstroms.

40. The display device of claim 33, wherein the light emitting material includes a semiconductor material.

41. The display device of claim 33, wherein the light emitting material includes an organic compound.

42. The display device of claim 33, wherein the light emitting material includes a light emitting polymer.

43. The display device of claim 42, wherein the light emitting polymer has a thickness from 20 to 60 nm.

44. The display device of claim 1, wherein the at least one light management feature is microreplicated onto the first panel.

45. The display device of claim 1, wherein the first panel is substantially transparent.

46. The display device of claim 45, wherein the first panel is in contact with the light control device.

47. The display device of claim 1, wherein the light management feature is on a side of the first panel that is closest to the light control device.

48. The display device of claim 1, wherein the light management feature is on a side of the first panel that is farthest to the light control device.

49. The display device of claim 1, wherein the first panel is a flexible panel.

50. The display device of claim 1, wherein the first panel is a rigid panel.

51. The display device of claim 1, wherein the second panel is a flexible panel.

52. The display device of claim 1, wherein the second panel is a rigid panel.

53. The display device of claim 1, wherein the first panel is made of a polymer material.

54. The display device of claim 1, wherein the first panel is made of glass.

55. The display device of claim 1, wherein the second panel is made of a polymer material.

56. The display device of claim 1, wherein the second panel is made of glass.

57. The display device of claim 1, wherein the light control device is a liquid crystal display.

58. The display device of claim 1, wherein the light management feature is on a side of the first panel that is closest to the light control device, and wherein the first panel includes spacers on a side that is farthest from the light control device.

59. The display device of claim 58, wherein the spacers define gaps between the first panel and the light emitting structure, and further comprising an inert gas in the gaps.

60. The display device of claim 58, wherein the spacers are a brightness enhancement film.

61. The display device of claim 1, wherein the second panel includes a reflective film.

62. The display device of claim 1, wherein the light control device is a first light control device, and further comprising a second light control device coupled to the backlight on an opposite side of the backlight from the first light control device.

63. The display device of claim 62, wherein the second panel also includes at least one light management feature.

64. The display device of claim 62, wherein the first and second panels are both transparent.

65. The display device of claim 62, wherein the light emitting structure includes an anode, a cathode, and a light emitting material between the anode and the cathode, and wherein the anode and the cathode are substantially transparent.

66. A method of making a display device, the method comprising:

forming a backlight, including;

forming a light management feature on a first panel;

forming a light emitting structure;

adhering a second panel to the first panel, with the light emitting structure therebetween; and

coupling the backlight to a light control device.

67. The method of claim 66, wherein the forming the light emitting structure includes forming the light emitting structure upon the first panel.

68. The method of claim 66, wherein the forming the light emitting structure includes forming the light emitting structure upon the second panel.

69. The method of claim 66, wherein the adhering the second panel to the first panel includes placing the panels together in a pick and place operation.

70. The method of claim 69, wherein one of the panels is a rigid panel, and the other of the panels is a flexible panel, and wherein the placing the panels together includes using a pick and place device to place the rigid panel on a web that includes the flexible panel.

71. The method of claim 70, wherein the first panel is the flexible panel and the second panel is the rigid panel.

72. The method of claim 71, wherein the forming the light management feature includes microreplicating protrusions on the first panel.

73. The method of claim 72, wherein the microreplicating protrusions includes microreplicating prism-shaped protrusions.

74. The method of claim 66, wherein the adhering the first panel and the second panel includes placing the panels together in a roll operation.

75. The method of claim 74, wherein the panels are both flexible panels.

76. The method of claim 66, wherein the forming the light emitting structure includes:

depositing a first electrode on one of the panels;

depositing a light emitting material on the first electrode; and

depositing a second electrode on the light emitting material.

77. The method of claim 66, wherein the coupling includes adhering the light management feature to the light control device.

78. A display device comprising:

a light control device having a plurality of picture elements; and

a backlight coupled to the light control device, wherein the backlight includes;

a first panel that includes a first light management feature;

a second panel that includes a second light management feature, wherein the second panel is sealingly adhered to the first panel; and

a light emitting structure between the first and second panels.

79. The display device of claim 78, wherein at least one of the light management features includes a brightness enhancement film.

80. The display device of claim 78, wherein at least one of the light management features includes a polarizing film.

81. The display device of claim 78, wherein at least one of the light management features includes a reflective film.

82. The display device of claim 78, wherein the first and second light management features are each selected from a group consisting of a brightness enhancement film, a reflective film, a transflective film, a polarizing film, and a light diffusing film.

83. The display device of claim 82, wherein the first and second light management features are different types of light management features.

84. The display device of claim 83, wherein one of the light management features is a brightness enhancement film, and the other of the light management features is a reflective film.

85. The display device of claim 78, wherein the light emitting structure includes an anode, a cathode, and a light emitting material between the anode and the cathode.

86. The display device of claim 85, wherein the light emitting material includes a polymer emitter.

87. The display device of claim 85, wherein the light emitting material includes an organic emitter.

88. The display device of claim 78, wherein the first panel is substantially transparent.

89. The display device of claim 88, wherein the first panel is in contact with the light control device.

90. The display device of claim 78, wherein the first panel is a flexible panel.

91. The display device of claim 78, wherein the second panel is a flexible panel.

92. The display device of claim 78, wherein the first panel and the second panel are both flexible panels.

93. The display device of claim 78, wherein the light control device is a liquid crystal display.

94. The display device of claim 78, wherein the light management feature is on a side of the first panel that is closest to the light control device, and wherein the first panel includes spacers on a side that is farthest from the light control device.

95. The display device of claim 94, wherein the spacers define gaps between the first panel and the light emitting structure, and further comprising an inert gas in the gaps.

96. The display device of claim 94, wherein the spacers are a brightness enhancement film.