Light guide panel, back light assembly and display apparatus each having the light guide panel and method of manufacturing the light guide panel

Patent metadata

Field	Value
Publication number	US-9618674-B2
Application number	US-201414164543-A
Country	US
Kind code	B2
Filing date	Jan 27, 2014
Priority date	Sep 30, 2013
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

A light guide panel, back light assembly and display apparatus are provided. According to an aspect of the inventive concept, there is provided the light guide panel which includes a top surface, a bottom surface, and four side surfaces, and one of the four side surfaces may be a light incident surface.

First claim

What is claimed is:

1. A light guide panel, comprising:
a top surface;
a bottom surface configured to be opposite to the top surface and facing a reflective sheet;
side surfaces connecting the top surface and the bottom surface, the side surfaces including a light incident surface and
an opposite surface opposite to the light incident surface,
wherein:
the bottom surface comprises a flat reference surface and a plurality of diffusion patterns including a plurality of recesses recessed from the flat reference surface and a plurality of protrusions protruding from the flat reference surface and formed along at least parts of circumferences of the recesses;
each of the plurality of protrusions includes a first protrusion disposed in a first region with respect to a reference line and a second protrusion disposed in a second region with respect to the reference line, the reference line extending substantially perpendicular to the light incident surface, passing through each of centers of the plurality of recesses and dividing each of the plurality of recesses in half into the first region and the second region; and
each of a volume of the second protrusions is less than half each of a volume of the first protrusions, and
wherein each of the first regions is disposed at the same one side with respect to the reference line.

2. The light guide panel of claim 1 , wherein the top surface comprises a first flat surface extending horizontally from an upper edge of the light incident surface, an inclined surface inclined downwardly from an edge of the first flat surface, and a second flat surface extending horizontally from a lower edge of the inclined surface.

3. The light guide panel of claim 1 , wherein the light guide panel is formed of one or more selected from the group consisting of polycarbonate (PC) and polymethylmethacrylate (PMMA).

4. The light guide panel of claim 1 , wherein the light guide panel has a thickness of about 100 to about 400 μm.

5. The light guide panel of claim 1 , wherein the light guide panel is manufactured by extrusion molding method.

6. The light guide panel of claim 1 , wherein residual stress is substantially uniform throughout the entire light guide panel.

7. The light guide panel of claim 1 , wherein the light guide panel has a melt mass flow rate (MFR) of about 20 to about 60 cm 3 /10 min.

8. The light guide panel of claim 1 , wherein the light guide panel has a tensile modulus of about 1800 to about 2200 Mpa.

9. The light guide panel of claim 1 , wherein the light guide panel has a flexural strength of about 85 to about 95 Mpa.

10. The light guide panel of claim 1 , wherein a maximum height of the second protrusions is equal to or less than half a maximum height of the first protrusions.

11. The light guide panel of claim 1 , further comprising:
third and fourth side surfaces perpendicular to the light incident surface and the opposite surface,
wherein the plurality of reference lines extend in parallel with each other, the first regions face toward the third side surface and the second regions face toward the fourth side surface.

12. The light guide panel of claim 1 , wherein a height of the first protrusion is increased according to an increase in distance from the reference line.

13. The light guide panel of claim 1 , wherein a volume of the second protrusions is substantially zero.

14. A light guide panel manufactured by extrusion, comprising:
a top surface;
a bottom surface configured to be opposite to the top surface;
side surfaces connecting the top surface and the bottom surface, the side surfaces including a light incident surface and an opposite surface opposite to the light incident surface,
wherein the light guide panel has a tensile modulus of 1800 Mpa to 2200 Mpa, a melt mass flow rate (MFR) of 20 cm 3 /10 min to 60 cm 3 /10 min, and a flexural strength of 85 Mpa to 95 Mpa.

15. A liquid crystal display, comprising:
a light guide panel;
a backlight assembly configured to include a light source unit disposed on one side of the light guide panel and a reflective sheet disposed below the light guide panel;
one or more optical sheets configured to be disposed over the backlight assembly; and
a display panel configured to be disposed on the optical sheets,
wherein the light guide panel comprises a top surface, a bottom surface opposite to the top surface and facing a reflective sheet, and side surfaces connecting the top surface and the bottom surface, the side surfaces including a light incident surface and an opposite surface opposite to the light incident surface,
wherein:
the bottom surface comprises a flat reference surface and a plurality of diffusion patterns including a plurality of recesses recessed from the flat reference surface and a plurality of protrusions protruding from the flat reference surface and formed along at least parts of circumferences of the recesses;
the plurality of protrusions include first protrusions disposed in first regions with respect to a plurality of reference lines and second protrusions disposed in second regions with respect to the plurality of reference lines, the plurality of reference lines extending substantially perpendicular to the light incident surface, passing through centers of the plurality of recesses and dividing the plurality of recesses in half into the first regions and the second regions; and
a volume of the second protrusions is less than half a volume of the first protrusions.

16. The display device of claim 15 , wherein the top surface comprises a first flat surface extending horizontally from an upper edge of the light incident surface, an inclined surface inclined downwardly from an edge of the first flat surface, and a second flat surface extending horizontally from a lower edge of the inclined surface.

17. The display device of claim 16 , wherein the light guide panel has a thickness of about 100 to about 400 μm.

Assignees

• Samsung Display Co Ltd

Inventors

• Kim Hyoung Joo
• Kang Dong Yeon
• Kim Rae Young
• Song Min Young
• Shim Sung Kyu
• Lee Sang Duk

Classifications

• G02B6/0016 Primary

  Grooves, prisms, gratings, scattering particles or rough surfaces · CPC title

• B29D11/00663

  Production of light guides · CPC title

• G02B6/0065

  Manufacturing aspects; Material aspects · CPC title

• G02B6/002

  by shaping at least a portion of the light guide, e.g. with collimating, focussing or diverging surfaces · CPC title

• G02B6/0061

  to provide homogeneous light output intensity · CPC title