Optical film
The subject invention provides an optical film comprising a transparent substrate and a structured surface layer, wherein the structured layer is positioned on the upper surface of the substrate and comprises a plurality of non-parallel, adjacent columnar structures. The optical film according to the subject invention can effectively enhance the brightness of a liquid crystal display and reduce the optical interference.
1. An optical film, comprising:
a plastic substrate, and
a structured surface layer, positioned on one side of the substrate,
wherein the structured surface layer has an irregular brightness enhancing structure that comprises a plurality of non-parallel, adjacent columnar structures, wherein the plurality of non-parallel, adjacent columnar structures a set of two non-parallel, crossed columnar structures and a set of two non-parallel, non-crossed columnar structures.
2. The optical film as claimed in claim 1 , wherein the columnar structures are selected from the group consisting of prismatic columns, arc columns and a combination thereof .
3. The optical film as claimed in claim 1 , wherein the columnar structures are prism columns.
4. The optical film as claimed in claim 3 , wherein the prism columns have an apex angle in a range from 50° to 120°.
5. The optical film as claimed in claim 4 , wherein the apex angle of the prism columns is in a range from 85° to 95°.
6. The optical film as claimed in claim 1 , wherein the columnar structures are arc columns.
7. The optical film as claimed in claim 1 , wherein the columnar structures comprise a combination of prism columns and arc columns.
8. The optical film as claimed in claim 1 , wherein the plurality of non-parallel, adjacent columnar structures are linear.
9. The optical film according to claim 1 , wherein the structured surface layer is produced by forming a colloidal coating layer on the plastic substrate and then roller embossing with a roller having grooves that form said structured surface layer with said plurality of non-parallel, adjacent columnar structures.
10. An optical film, comprising:
a polyester resin substrate, and
a structured surface layer, positioned on the upper surface of the substrate,
wherein the structured surface layer has an irregular brightness enhancing structure that comprises a plurality of non-parallel, adjacent linear prism columnar structures, wherein the plurality of non-parallel, adjacent linear prism columnar structures comprise a set of two non-parallel crossed linear prism columnar structures and a set of two non-parallel, non-crossed linear prism columnar structures, the width of the columnar structures is in a range from 1 μm to 100 μm, and the optical film has a refractive index of at least 1.50.
11. The optical film as claimed in claim 10 , wherein the structured surface layer further comprises a set of two columnar structures parallel to each other.
12. The optical film as claimed in claim 10 , wherein the prism columnar structures have an apex angle in a range from 50° to 120°.
13. The optical film as claimed in claim 12 , wherein the apex angle of the prism columnar structures is in a range from 85° to 95°.
14. The optical film as claimed in claim 10 , wherein the structured surface layer is composed of a (meth)acrylate resin.
15. The optical film as claimed in claim 10 , wherein the lower surface of the substrate is smooth.
16. The optical film as claimed in claim 10 , wherein the lower surface of the substrate is unsmooth.
17. The optical film according to claim 10 , wherein the structured surface layer is produced by forming a colloidal coating layer on the plastic substrate and then roller embossing with a roller having grooves that form said structured surface layer with said plurality of non-parallel, adjacent linear prism columnar structures.
18. A liquid crystal display, comprising:
a surface light source device; and
an optical film disposed above the light-out plane of the surface light source device,
wherein the optical film has a structured surface layer, and the structured surface layer has an irregular brightness enhancing structure that comprises a plurality of non-parallel, adjacent columnar structures, wherein the plurality of non-parallel, adjacent columnar structures comprise a set of two non-parallel, crossed linear prism columnar structures and a set of two non-parallel, non-crossed linear prism columnar structures.
19. The liquid crystal display according to claim 18 , wherein the structured surface layer is produced by forming a colloidal coating layer on the plastic substrate and then roller embossing with a roller having grooves that form said structured surface layer with said plurality of non-parallel, adjacent columnar structures.