Optical film, barrier film, light conversion member, backlight unit, and liquid crystal display device

Patent metadata

Field	Value
Publication number	US-9632229-B2
Application number	US-201615041673-A
Country	US
Kind code	B2
Filing date	Feb 11, 2016
Priority date	Aug 12, 2013
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

A liquid crystal display device having high transmittance and a high color reproduction region, which includes a backlight unit including a light conversion member; and a liquid crystal cell and in which the light conversion member includes a light conversion layer containing a fluorescent material and an optical film arranged on both surfaces of the light conversion layer, the optical film includes an optical thin film forming an air interface, and a layer directly adjacent to the optical thin film, the liquid crystal display device satisfies n(535)<nu(535), n(535)×d is in a specific range, transmittance of a laminated body of the optical thin film and the layer directly adjacent to the optical thin film is in a specific range, and the backlight unit emits blue light, green light, and red light.

First claim

What is claimed is:

1. A liquid crystal display device, comprising:
a backlight unit including a light conversion member; and
a liquid crystal cell,
wherein the light conversion member includes a light conversion layer containing a fluorescent material and an optical film arranged on both surfaces of the light conversion layer containing the fluorescent material,
the optical film includes an optical thin film forming an air interface, and a layer directly adjacent to the optical thin film,
the optical film satisfies the following Expression (1),
the optical film satisfies any one of the following Expressions (2-1), (2-2), and (2-3),
all transmittances of the optical film at a Y value in an XYZ color system at a wavelength of 430 nm to 470 nm, a wavelength of 515 nm to 555 nm, and a wavelength of 600 nm to 650 nm are greater than transmittance of the optical film at a Y value in an XYZ color system at a wavelength of greater than 470 nm and less than 515 nm and a wavelength of greater than 555 nm and less than 600 nm,
the backlight unit emits blue light which has an emission peak wavelength in a wavelength range of 430 nm to 480 nm and has a full width at half maximum of less than or equal to 100 nm, green light which has an emission peak wavelength in a wavelength range of 500 nm to 600 nm and has a full width at half maximum of less than or equal to 100 nm, and red light which has an emission peak wavelength in a wavelength range of 600 nm to 650 nm and has a full width at half maximum of less than or equal to 100 nm,
n (535)< nu (535)  Expression (1)

in Expression (1), n(535) represents a refractive index of the optical thin film at a wavelength of 535 nm, and nu(535) represents a refractive index of the layer directly adjacent to the optical thin film at a wavelength of 535 nm,
1.15 μm≦ n (535)× d≦ 1.25 μm  Expression (2-1)

1.42 μm≦ n (535)× d≦ 1.52 μm  Expression (2-2)

1.69 μm≦ n (535)× d≦ 1.79 μm  Expression (2-3)

in Expressions (2-1), (2-2), and (2-3), n(535) represents a refractive index of the optical thin film at a wavelength of 535 nm, d represents a thickness of the optical thin film, and the unit is μm.

2. The liquid crystal display device according to claim 1 ,
wherein the optical film is an optical film in which at least a first organic film, a substrate, an inorganic film, and a second organic film are laminated in this order, and
the optical thin film is the first organic film, and the substrate is the layer directly adjacent to the optical thin film.

3. The liquid crystal display device according to claim 2 ,
wherein the inorganic film is a silicon oxide film or a silicon oxide nitride film.

4. The liquid crystal display device according to claim 1 ,
wherein the optical thin film contains a Cardo polymer.

5. The liquid crystal display device according to claim 1 ,
wherein the optical film of the liquid crystal display device satisfies any one of the following Expressions (2-1A), (2-2A), and (2-3A),
1.16 μm≦ n (535)× d≦ 1.24 μm  Expression (2-1A)

1.46 μm≦ n (535)× d≦ 1.51 μm  Expression (2-2A)

1.70 μm≦ n (535)× d≦ 1.78 μm  Expression (2-3A)

in Expressions (2-1A), (2-2A), and (2-3A), n(535) represents a refractive index of the optical thin film at a wavelength of 535 nm, d represents a thickness of the optical thin film, and the unit is μm.

6. The liquid crystal display device according to claim 5 ,
wherein the liquid crystal display device satisfies Expression (2-2A) described above.

7. The liquid crystal display device according to claim 1 ,
wherein all transmittances of a laminated body of the optical thin film and the layer directly adjacent to the optical thin film at a Y value in an XYZ color system at a wavelength of 430 nm to 470 nm, a wavelength of 515 nm to 555 nm, and a wavelength of 600 nm to 650 nm are greater than or equal to 97%.

8. The liquid crystal display device according to claim 1 ,
wherein all transmittances of the laminated body of the optical thin film and the layer directly adjacent to the optical thin film at a Y value in an XYZ color system at a wavelength of greater than 470 nm and less than 515 nm and a wavelength of greater than 555 nm and less than 600 nm are less than 97%.

9. The liquid crystal display device according to claim 1 ,
wherein the backlight unit includes a light guide plate, and
the light conversion member is arranged between the light guide plate and the liquid crystal cell.

10. The liquid crystal display device according to claim 1 ,
wherein the optical film is a barrier film,
the barrier film is for the light conversion member containing the fluorescent material, and
oxygen permeability of the barrier film is less than or equal to 0.5 cm 3 /m 2 /day/atm.

11. The liquid crystal display device according to claim 1 ,
wherein the fluorescent material is a quantum dot.

12. An optical film for a light conversion member containing a fluorescent material, comprising:
an optical thin film forming an air interface; and
a layer directly adjacent to the optical thin film,
wherein the optical film satisfies the following Expression (1),
the optical film satisfies any one of the following Expressions (2-1), (2-2), and (2-3), all transmittances of the optical film at a Y value in an XYZ color system at a wavelength of 430 nm to 470 nm, a wavelength of 515 nm to 555 nm, and a wavelength of 600 nm to 650 nm are greater than transmittance of the optical film at a Y value in an XYZ color system at a wavelength of greater than 470 nm and less than 515 nm and a wavelength of greater than 555 nm and less than 600 nm,
n (535)< nu (535)  Expression (1)

in Expression (1), n(535) represents a refractive index of the optical thin film at a wavelength of 535 nm, and nu(535) represents a refractive index of the layer directly adjacent to the optical thin film at a wavelength of 535 nm,
1.15 μm≦ n (535)× d≦ 1.25 μm  Expression (2-1)

1.42 μm≦ n (535)× d≦ 1.52 μm  Expression (2-2)

1.69 μm≦ n (535)× d≦ 1.79 μm  Expression (2-3)

in Expressions (2-1), (2-2), and (2-3), n(535) represents a refractive index of the optical thin film at a wavelength of 535 nm, d represents a thickness of the optical thin film, and the unit is μm.

13. The optical film according to claim 12 ,
wherein the optical film is an optical film in which at least a first organic film, a substrate, an inorganic film, and a second organic film are laminated in this order, and
the optical thin film is the first organic film, and the substrate is the layer directly adjacent to the optical thin film.

14. The optical film according to claim 13 ,
wherein the inorganic film is a silicon oxide film or a silicon oxide nitride film.

15. The optical film according to claim 12 ,
wherein the optical thin film contains a Cardo polymer.

16. The optical film according to claim 12 ,
wherein the optical film satisfies any one of the following Expressions (2-1A), (2-2A), and (2-3A),
1.16 μm≦ n (535)× d≦ 1.24 μm  Expression (2-1A)

1.46 μm≦ n (535)× d≦ 1.51 μm  Expression (2-2A)

1.70 μm≦ n (535)× d≦ 1.78 μm  Expression (2-3A)

in Expressions (2-1A), (2-2A), and (2-3A), n(535) represents a refractive index of the optical thin film at a wavelength of 535 nm, d represents a thickness of the optical thin film, and the unit is μm.

17. The optical film according to claim 16 ,
wherein the optical film satisfies Expression (2-2A) described above.

18. The optical film according to claim 12 ,
wherein all transmittances of a laminated body of the optica

Assignees

• Fujifilm Corp

Inventors

• Yamada Naoyoshi
• Oba Tatsuya
• Saitoh Yukito
• Ohmuro Katsufumi
• Watano Akiko

Classifications

• G02B6/005 Primary

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

• G02F2001/133614

  Physics · mapped topic

• G02B6/0023 Primary

  provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source · CPC title

• G02F1/133615

  Edge-illuminating devices, i.e. illuminating from the side · CPC title

• G02F1/133617

  Illumination with ultraviolet light; Luminescent elements or materials associated to the cell · CPC title