Brightness enhancing film and fabrication method thereof

Abstract

A brightness enhancing film and fabrication method thereof. The brightness enhancing film comprises a plurality of nanoparticles dispersed in a polymer film. Dispersion density of the nanoparticles along a non-stretching direction is about 5-10 times that along a stretching direction. A combination of the brightness enhancing film and a quarter wavelength plate (λ/4 plate) is interposed between a display panel and a backlight module, thereby improving brightness and reducing power consumption.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:

FIG. 1 is a schematic stereograph of a conventional DBEF reflective polarizer;

FIG. 2 is a schematic cross section of a conventional liquid crystal display module with a cholesteric liquid crystal plate and a quarter wavelength plate;

FIG. 3 is a schematic plan view of a brightness enhancing film according to an embodiment of the invention;

FIG. 4 is a schematic cross section of a liquid crystal display module with a brightness enhancing film and a quarter wavelength plate according to an embodiment of the invention.

Claims

1. A brightness enhancing film, comprising: a polymer film; anda plurality of nanoparticles dispersed in the polymer film, with dispersion of the nanoparticles in the polymer film including a stretching direction and a non-stretching direction, with dispersion density of the nanoparticles along the stretching direction different from that along the non-stretching direction.

2. The brightness enhancing film as claimed in claim 1, wherein the dispersion density of the nanoparticles along the non-stretching direction is 5-10 times that along the stretching direction.

3. The brightness enhancing film as claimed in claim 1, wherein the polymer film comprises a thermosetting or a thermoplastic polymer.

4. The brightness enhancing film as claimed in claim 1, wherein the nanoparticles comprises a metal or dielectric material.

5. The brightness enhancing film in claim 1, wherein the nanoparticles are metal.

6. The brightness enhancing film as claimed in claim 1, wherein the nanoparticles have a diameter from 100 to 200 nm.

7. The brightness enhancing film as claimed in claim 1, wherein the dispersion density of the nanoparticles is from 1 to 100 particles/(μm)3.

8. The brightness enhancing film as claimed in claim 1, which has a thickness from 20 to 200 μm.

9. A method of fabricating a brightness enhancing film, comprising: mixing a plurality of nanoparticles with a polymer or a polymer precursor;processing the mixture into a film, the plurality of nanoparticles uniformly dispersed in the film; andstretching the film along a stretching direction, such that the dispersion density of the nanoparticles along the stretching direction is different from that along a non-stretching direction.

10. The method as claimed in claim 9, wherein the dispersion density of the nanoparticles along the non-stretching direction is 5-10 times that along the stretching direction.

11. The method as claimed in claim 9, wherein the diameter of the nanoparticles is from 100 to 200 nm.

12. The method as claimed in claim 9, wherein the dispersion density of the nanoparticles is from 1 to 100 particles/(μm)3.

13. The method as claimed in claim 9, wherein the nanoparticles comprise a metal or dielectric material.

14. The method as claimed in claim 9, wherein the polymer comprises a thermosetting or a thermoplastic polymer.

15. The method as claimed in claim 9, wherein the nanoparticles are metal.

16. The method as claimed in claim 9, wherein a thickness of the brightness enhancing film is from 20 to 200 μm.

17. A liquid crystal display module, comprising: a display panel;a backlight module;a quarter wavelength plate and a brightness enhancing film as claimed in claim 1 interposed between the display panel and the backlight module with the brightness enhancing film facing the display panel; anda pair of polarizers sandwiching the display panel.