Backlight unit and display device comprising same

Patent metadata

Field	Value
Publication number	US-10168461-B2
Application number	US-201515321643-A
Country	US
Kind code	B2
Filing date	Feb 25, 2015
Priority date	Jun 27, 2014
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A backlight unit including a light source formed to provide primary light; a quantum dot phosphor excited by the primary light provided from the light source to emit secondary light having a wavelength different from a wavelength of the primary light and disposed to be spaced apart from the light source; an optical agent absorbing light having a specific wavelength from the primary light provided by the light source and the secondary light emitted from the quantum dot phosphor; and a matrix configured to support the quantum dot phosphor and the optical agent. Further, the quantum dot phosphor and the optical agent are randomly mixed in the matrix; and the quantum dot phosphor, the optical agent, and the matrix form a composite.

First claim

The invention claimed is:

1. A backlight unit comprising:
a light source formed to provide primary light;
a quantum dot phosphor excited by the primary light provided from the light source to emit secondary light having a wavelength different from a wavelength of the primary light and disposed to be spaced apart from the light source;
an optical agent absorbing light having a specific wavelength from the primary light provided by the light source and the secondary light emitted from the quantum dot phosphor; and
a matrix configured to support the quantum dot phosphor and the optical agent, wherein
the quantum dot phosphor and the optical agent are randomly mixed in the matrix, and
the quantum dot phosphor, the optical agent, and the matrix form a composite.

2. The backlight unit of claim 1 , wherein
the optical agent includes:
at least one of a dye absorbing or reflecting light having a specific wavelength;
a pigment absorbing or reflecting light having a specific wavelength; and
a luminescent dye absorbing light having a specific wavelength and emitting light having a wavelength longer than that of the absorbed light.

3. The backlight unit of claim 2 , wherein the optical agent includes dyes or pigments coloring red, green, or purple.

4. The backlight unit of claim 3 , wherein the red coloring dye or pigment reflects light with 620-650 nm, green coloring dye or pigment reflects light with 520-550 nm, blue coloring dye or pigment reflects light with 440-460 nm, and purple coloring dye or pigment reflects light with 400-460 nm.

5. The backlight unit of claim 2 , wherein
the dye or pigment absorbs light with 480-520 nm, 540-630 nm, or 650 nm or greater.

6. The backlight unit of claim 2 , wherein
the optical agent includes luminescent dyes absorbing light with 480-520 nm, 540-630 nm, or 650 nm or greater, and emitting light with 620-650 nm, 520-550 nm, 440-460 nm, or 400-460 nm.

7. The backlight unit of claim 1 , wherein
the light source is disposed on one surface of a printed circuit board (PCB), and
the composite is provided in the form of a film, provided in a position spaced apart from the PCB, and disposed to face the light source.

8. The backlight unit of claim 1 , further comprising:
a light guide plate guiding light provided from the light source,
wherein
the light source is disposed on the edge of the light guide plate, and
the composite is provided in the form of a tube and disposed between the light source and the light guide plate.

9. The backlight unit of claim 1 , wherein
the backlight unit further includes a light guide plate guiding light provided from the light source,
the light source is disposed on the edge of the light guide plate, and
the composite is provided in the form of a film and disposed to face one surface of the light guide plate.

10. The backlight unit of claim 1 , further comprising:
a first matrix configured to support the quantum dot phosphor; and
a second matrix configured to support the optical agent,
wherein
the quantum dot phosphor and the first matrix form a quantum dot phosphor film or a quantum dot phosphor tube,
the optical agent and the second matrix form an optical film, and
the optical film is stacked on the quantum dot phosphor film or the quantum dot phosphor tube.

11. The backlight unit of claim 10 , wherein
the light source is disposed on one surface of a printed circuit board (PCB),
the quantum dot phosphor film is provided in a position spaced apart from the PCB and disposed to face the light source, and
the optical film is disposed on the opposite side of the light source with respect to the first matrix.

12. The backlight unit of claim 10 , further comprising:
a light guide plate guiding light provided from the light source,
the light source is disposed on the edge of the light guide plate,
the quantum dot phosphor tube is disposed to face one surface of the light guide plate, and
the optical film is disposed on the opposite side of the light guide plate with respect to the quantum dot phosphor tube.

13. The backlight unit of claim 10 , further comprising:
a light guide plate guiding light provided from the light source,
wherein
the light source is disposed on the edge of the light guide plate,
the quantum dot phosphor film is disposed to face one surface of the light guide plate, and
the optical film is disposed on the opposite side of the light guide plate with respect to the quantum dot phosphor film.

14. A backlight unit comprising:
a light source formed to provide primary light;
a quantum dot phosphor excited by the primary light provided from the light source to emit secondary light having a wavelength different from a wavelength of the primary light and disposed to be spaced apart from the light source;
an optical agent absorbing light having a specific wavelength from the primary light and the secondary light;
a bead configured to support the quantum dot phosphor and the optical agent; and
a matrix configured to support the bead,
wherein the bead includes the quantum dot phosphor and the optical agent and forms a composite together with the matrix.

15. The backlight unit of claim 14 , wherein
the light source is disposed on one surface of a printed circuit board (PCB),
the composite is provided in the form of a film, provided in a position spaced apart from the PCB, and disposed to face the light source.

16. The backlight unit of claim 14 , further comprising:
a light guide plate guiding light provided from the light source,
wherein
the light source is disposed on the edge of the light guide plate, and
the composite is provided in the form of a tube and disposed between the light source and the light guide plate.

17. The backlight unit of claim 14 , further comprising:
a light guide plate guiding light provided from the light source,
wherein
the light source is disposed on the edge of the light guide plate, and
the composite is provided in the form of a film and disposed to face one surface of the light guide plate.

18. A display device comprising:
a liquid crystal panel; and
a backlight unit emitting light to a rear side of the liquid crystal panel,
wherein the backlight unit includes:
a light source providing primary light;
a quantum dot phosphor exciting the primary light provided from the light source to emit secondary light having a wavelength different from a wavelength of the primary light, and disposed to be spaced apart from the light source; and
an optical agent absorbing light having a specific wavelength from the primary light provided by the light source and the secondary light emitted from the quantum dot phosphor; and
a matrix configured to support the quantum dot phosphor and the optical agent, wherein
the quantum dot phosphor and the optical agent are randomly mixed in the matrix, and
the quantum dot phosphor, the optical agent, and the matrix form a composite.

Assignees

• Lg Electronics Inc

Inventors

• Oh Jinmok
• Cho Byoungkwon
• Choi Moongoo

Classifications

• G02B6/005

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

• G02F1/133617

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

• G02F1/133308

  Support structures for LCD panels, e.g. frames or bezels · CPC title

• G02B6/0088

  of the light guide or other optical sheets in the package · CPC title

• G02B6/001

  the light being emitted along at least a portion of the lateral surface of the fibre · CPC title