Backlight unit and liquid crystal display device

Patent metadata

Field	Value
Publication number	US-2017162133-A1
Application number	US-201715434727-A
Country	US
Kind code	A1
Filing date	Feb 16, 2017
Priority date	Aug 18, 2014
Publication date	Jun 8, 2017
Grant date	—

Abstract

An aspect of the present invention relates to a backlight unit, including: a polarized light source unit which is capable of allowing polarized light to exit; and a condensing sheet which is disposed on the polarized light source unit on an exiting side, in which a depolarization degree of the condensing sheet is less than or equal to 0.1500, and a liquid crystal display device, including: the backlight unit; and a liquid crystal panel.

First claim

What is claimed is:

1 . A backlight unit, comprising:
a polarized light source unit which is capable of allowing polarized light to exit; and a condensing sheet which is disposed on the polarized light source unit on an exiting side, wherein a depolarization degree of the condensing sheet is less than or equal to 0.1500.

2 . The backlight unit according to claim 1 ,
wherein a visible light reflectivity measured on a surface of the condensing sheet on the polarized light source unit side is less than or equal to 70%.

3 . The backlight unit according to claim 1 ,
wherein the polarized light source unit includes at least a light source and a reflective polarizer.

4 . The backlight unit according to claim 3 ,
wherein the polarized light source unit includes a quantum dot-containing layer between the light source and the reflective polarizer.

5 . The backlight unit according to claim 4 ,
wherein the light source is a blue light source, and the quantum dot-containing layer contains a quantum dot which is excited by exciting light and emits red light arid a quantum dot which is excited by exciting light and emits green light.

6 . The backlight unit according to claim 5 , further comprising:
a selective reflective layer having a reflective center wavelength in a wavelength range of b e light between the quantum dot-containing layer and the reflective polarizer.

7 . The backlight unit according to claim 5 , further comprising:
a selective reflective layer having a reflective center wavelength in a wavelength range of green light and in a wavelength range of red light between the light source and the quantum dot-containing layer.

8 . The backlight unit according to claim 1 ,
wherein the polarized light source unit includes at least a light source and a quantum rod-containing layer.

9 . The backlight unit according to claim 8 , further comprising:
a selective reflective polarizer having a reflective center wavelength in a wavelength range of blue light between the quantum rod-containing layer and the condensing sheet, wherein the light source is a blue light source, and the quantum rod-containing layer contains a quantum rod which is excited by exciting light and emits red polarized light and a quantum rod which is excited by exciting light and emits green polarized light.

10 . The backlight unit according to claim 9 , further comprising:
a selective reflective polarizer having a reflective center wavelength in a wavelength range of green light and in a wavelength range of red light between the light source and the quantumrod-containing layer.

11 . The backlight unit according to claim 1 ,
wherein the condensing sheet includes a plurality of convex portions on a surface on the exiting side.

12 . The backlight unit according to claim 11 ,
wherein a sectional shape of the convex portion is a curved surface shape.

13 . The backlight unit according to claim 1 ,
wherein the condensing sheet is a laminated sheet of two or more layers, and includes a plurality of convex portions protruding to the exiting side on an interface between two layers.

14 . The backlight unit according to claim 13 ,
wherein a sectional shape of the convex portion is a curved surface shape.

15 . The backlight unit according to claim 1 ,
wherein the condensing sheet is a gradient index rod lens array sheet,

16 . The backlight unit according to claim 15 ,
wherein the gradient index rod lens is a cylinder lens.

17 . A liquid crystal display device, comprising:
the backlight unit according to claim 1 ; and a liquid crystal panel.

Assignees

• Fujifilm Corp

Inventors

• Sekiguchi Megumi
• Kamo Makoto

Classifications

• G09G3/36 Primary

  using liquid crystals · CPC title

• G02B6/005

  provided by one optical element, or plurality thereof, placed on the light output side of the light guide · CPC title

• G02F2202/36

  Micro- or nanomaterials · CPC title

• G02F1/133614

  using photoluminescence, e.g. phosphors illuminated by UV or blue light · CPC title

• G02B6/0056

  for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements · CPC title