Optical unit, a method of manufacturing the same, a backlight assembly having the same and a display device having the same

• US 7,450,809 B2
• Filed: 07/25/2006
• Issued: 11/11/2008
• Est. Priority Date: 07/25/2005
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Choi, Jin-Sung, Park, Jheen-Hyeok, Ha, Ju-Hwa
• Primary Examiner(s): HAHM, SARAH UH YOUNG
• Application Number:
  US11/492,714
• Publication Number:
  US 20070019131A1
• Time in Patent Office: 840 Days
• Field of Search: 385/146, 385/901
• US Class Current: 385/129
• CPC Class Codes: G02B 5/0215 the surface having a regular structure
• CPC Class Codes: G02B 5/0231 the surface having microprismatic or micropyramidal shape macroscopic prism arrays G02B5/045
• CPC Class Codes: G02B 5/0242 by means of dispersed particles
• CPC Class Codes: G02B 5/0278 used in transmission
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02B 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02F 1/133606 including a specially adapted diffusing, scattering or light controlling members
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses
• CPC Class Codes: G02F 1/133611 including means for improving the brightness uniformity
• CPC Class Codes: Y10S 385/901 Illuminating or display apparatus

Abstract

An optical unit, a method of manufacturing the same, a backlight assembly having the same and a display device have the same are provided. The optical unit includes a transparent body, a diffusion part and a luminance increasing part. The diffusion part is formed on or in the body to diffuse light. The luminance increasing part includes an embossing pattern formed on the body to increase a luminance of the diffused light when viewed on a plane.

Claims

1. An optical unit comprising:

a transparent body;

a diffusion part formed on the body to diffuse light; and

a luminance increasing part including an embossing pattern formed on the diffusion part to increase a luminance of the diffused light when viewed on a plane, wherein a first side of the diffusion part is in continuous contact with a surface of the body and a second side of the diffusion part is in continuous contact with a surface of the luminance increasing part,

wherein a side of the embossing pattern makes contact with the diffusion part.

2. The optical unit of claim 1, wherein the diffusion part comprises a plurality of diffusion elements.

3. The optical unit of claim 2, wherein the diffusion elements comprise gas bubbles.

4. The optical unit of claim 3, wherein each of the diffusion elements is about 1 μ

m to about 100 μ

m.

5. The optical unit of claim 2, wherein the diffusion elements comprise beads.

6. The optical unit of claim 1, wherein the luminance increasing part comprises an embossing part including a substantially polygonal pyramid shape having a rounded apex.

7. The optical unit of claim 1, wherein the luminance increasing part comprises an embossing part including a substantially polygonal pyramid shape and a substantially conical shape without a rounded apex.

8. The optical unit of claim 1, wherein the luminance increasing part comprises an embossing part that is protruded from the body, and the embossing part comprises a plurality of gas bubbles.

9. The optical unit of claim 1, wherein the luminance increasing part comprises an ultraviolet light curable resin.

10. The optical unit of claim 1, further comprising an ultraviolet light blocking layer formed on the body to prevent a coloration of the body, wherein the ultraviolet light blocking layer is not adjacent to the diffusion part.

11. A method of manufacturing an optical unit comprising:

forming a diffusion part on a transparent plate including a polymer resin; and

forming a luminance increasing part including an embossing pattern on the diffusion part, wherein a first side of the diffusion part is in continuous contact with a surface of the transparent plate and a second side of the diffusion part is in continuous contact with a surface of the luminance increasing part,

wherein a side of the embossing pattern makes contact with the diffusion part.

12. The method of claim 11, wherein the diffusion part is formed by:

supplying the transparent plate with gas at a pressure higher than an atmospheric pressure so that the gas is absorbed in the transparent plate; and

expanding the absorbed gas to form the gas bubbles in the transparent plate.

13. The method of claim 12, wherein the gas is absorbed in the transparent plate by ejecting the gas at the pressure higher than the atmospheric pressure so that the gas is injected into spaces formed by chains of high polymer molecules of the transparent plate.

14. The method of claim 12, wherein the gas bubbles are formed by:

heating the transparent plate having the absorbed gas to expand the absorbed gas; and

discharging the expanded gas from the transparent plate.

15. The method of claim 12, wherein the gas comprises at least one selected from the group consisting of air, carbon dioxide, nitrogen and oxygen.

16. The method of claim 12, wherein the diffusion part is formed by:

arranging diffusion beads in the transparent plate or on the surface of the transparent plate.

17. The method of claim 11, wherein the luminance increasing part is formed by:

coating an ultraviolet light curable resin layer on the transparent plate having the diffusion part;

pressing the ultraviolet light curable resin layer using a cast having a pattern corresponding to the embossing pattern to form the embossing pattern on the ultraviolet light curable resin layer; and

irradiating an ultraviolet light onto the ultraviolet light curable resin layer having the embossing pattern to solidify the ultraviolet light curable resin layer having the embossing pattern.

18. The method of claim 17, wherein the ultraviolet light curable resin comprises at least one selected from the group consisting of an acryl based resin, an acetophenone based resin, a benzophenone based resin and a thioxanthone based resin.

19. The method of claim 17, further comprising forming a plurality of gas bubbles in the ultraviolet light curable resin layer having the embossing pattern.

20. The method of claim 11, further comprising forming an ultraviolet light blocking layer on the transparent plate corresponding to the luminance increasing part.

21. A backlight assembly comprising:

a light source; and

an optical unit including;

a transparent body;

a diffusion part formed on the body to diffuse light generated from the light source; and

a luminance increasing part including an embossing pattern formed on the diffusion part to increase a luminance of the diffused light when viewed on a plane, wherein a first side of the diffusion part is in continuous contact with a top surface of the body and a second side of the diffusion part is in continuous contact with a surface of the luminance increasing part,

wherein a side of the embossing pattern makes contact with the diffusion part.

22. The backlight assembly of claim 21, wherein the luminance increasing part guides the diffused light toward a front of the optical unit.

23. The backlight assembly of claim 21, wherein the light source is arranged on a bottom surface of the body opposite the luminance increasing part, and the backlight assembly further comprises a diffusion sheet formed on the luminance increasing part to diffuse the light.

24. The backlight assembly of claim 21, further comprising:

a light guiding unit including;

a light incident portion through which the light generated from the light source is incident; and

a light exiting portion facing a bottom surface of the optical unit.

25. A display device comprising:

a display panel that displays an image based on uniform light; and

a backlight assembly supplying the display panel with the uniform light, the backlight assembly including;

a light source; and

an optical unit including a transparent body, a diffusion part formed on the body, the diffusion part having a porous medium to diffuse light generated from the light source, and a luminance increasing part including an embossing pattern formed on the diffusion part to increase a luminance of the diffused light when viewed on a plane to generate the uniform light, wherein a first side of the diffusion part is in continuous contact with a surface of the body and a second side of the diffusion part is in continuous contact with a surface of the luminance increasing part,

wherein a side of the embossing pattern makes contact with the diffusion part.