Moire reducing optical substrates with irregular prism structures

Patent metadata

Field	Value
Publication number	US-9448411-B2
Application number	US-201314010478-A
Country	US
Kind code	B2
Filing date	Aug 26, 2013
Priority date	Jun 9, 2005
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

An optical substrate having a structured surface that enhances brightness and reduces moiré effect. The optical substrate has a three-dimensionally varying, structured light output surface that comprises an irregular prismatic structure. The irregular prismatic structure may be viewed as comprising longitudinal prism blocks or rows thereof, arranged laterally defining peaks and valleys. Adjacent peaks, adjacent valleys, and/or adjacent peak and valley may be parallel or non-parallel, in an orderly, semi-orderly, random, or quasi-random manner. The lateral adjacent peaks, adjacent valleys, and/or adjacent peak and valley are not parallel. The adjacent irregular prism blocks may be irregular longitudinal sections having the same length, or random or quasi-random irregular sections having different lengths. The facets of each prism block may be flat, or curved (convexly and/or concavely).

First claim

The invention claimed is:

1. A light directing film comprising a structured major surface, wherein the structured major surface comprises a plurality of microstructures extending along a first direction, and wherein each microstructure comprises:
a first region with a constant height; and
a second region adjacent to the first region, wherein the second region has a non-constant height and a maximum height greater than the constant height of the first region, and wherein the first region and the second region have the same lateral cross-sectional shape.

2. A method of making a light directing film, comprising:
cutting a tool with a structured major surface, wherein the structured major surface comprises a plurality of grooves extending along a first direction, wherein each groove comprises:
a first region with a constant depth; and
a second region adjacent to the first region, wherein the second region has a non-constant depth and a maximum depth greater than the constant depth of the first region, wherein the first region and the second region have the same lateral cross-sectional shape; and

applying a material to the tool to form a film, wherein the film comprises an arrangement of microstructures corresponding to the grooves of the tool.

3. A light directing film comprising a first structured major surface defining the light output surface of the light directing film, a second major surface opposite to the first structured major surface and defining the light input surface of the light directing film and a reference plane between the first structured major surface and the second major surface, wherein the reference plane is substantially perpendicular to the thickness direction of the light directing film, wherein the first structured major surface comprises a plurality of prisms extending substantially along a first direction, wherein each of at least one of the plurality of prisms comprises a first portion and a second portion disposed along the first direction, wherein the first portion has a constant height relative to the reference plane and the second portion has a maximum height relative to the reference plane, wherein the maximum height of the second portion is larger than the constant height of the first portion; wherein the first portion has a first bottom width and the second portion has a maximum second bottom width, wherein the maximum second bottom width is larger than the first bottom width.

4. A light directing film comprising a first structured major surface defining the light output surface of the light directing film, a second major surface opposite to the first structured major surface and defining the light input surface of the light directing film and a reference plane between the first structured major surface and the second major surface, wherein the reference plane is substantially perpendicular to the thickness direction of the light directing film, wherein the first structured major surface comprises a plurality of prisms extending substantially along a first direction, wherein each of at least one of the plurality of prisms comprises a first portion and a second portion disposed along the first direction, wherein the first portion has a first constant height relative to the reference plane and the second portion has a second constant height relative to the reference plane, wherein the second constant height of the second portion is larger than the first constant height of the first portion.

5. A light directing film comprising a first structured major surface, a second major surface opposite to the first structured major surface and a reference plane between the first structured major surface and the second major surface, wherein the reference plane is substantially perpendicular to the thickness direction of the light directing film, wherein the first structured major surface comprises a plurality of microstructures extending substantially along a first direction, wherein each of at least one of the plurality of microstructures comprises a first portion and a second portion disposed along the first direction, wherein the first portion has a constant height relative to the reference plane and the second portion has a maximum height relative to the reference plane, wherein the maximum height of the second portion is larger than the constant height of the first portion; wherein the first portion has a first cross-sectional shape and the second portion has a second cross-sectional shape, wherein the first cross-sectional shape and the second cross-sectional shape are the same.

6. The light directing film according to claim 5 , wherein the first cross-sectional shape has a first bottom width and the second cross-sectional shape has a maximum second bottom width, wherein the maximum second bottom width is larger than the first bottom width.

7. The light directing film according to claim 5 , wherein the second major surface defines the light input surface of the light directing film and the first structured major surface defines the light output surface of the light directing film.

8. The light directing film according to claim 5 , wherein each of the plurality of microstructures is a prism.

9. The light directing film according to claim 5 , wherein each of the first cross-sectional shape and the second cross-sectional shape is a triangle.

10. The light directing film according to claim 5 , wherein each of the at least one of the plurality of microstructure comprises a set of first portions and a set of second portions alternating with the set of first portions.

11. The light directing film of claim according to 5 , wherein each of the plurality of microstructures extends continuously and linearly along the first direction.

12. The light directing film according to claim 5 , wherein the first portion has a first peak vertex angle and the second portion has a second peak vertex angle, wherein the second peak vertex angle is substantially equal to the first peak vertex angle.

13. A light directing film comprising a first structured major surface, a second major surface opposite to the first structured major surface and a reference plane between the first structured major surface and the second major surface, wherein the reference plane is substantially perpendicular to the thickness direction of the light directing film, wherein the first structured major surface comprises a plurality of microstructures extending substantially along a first direction, wherein each of at least one of the plurality of microstructures comprises a first portion and a second portion disposed along the first direction, wherein the first portion has a first constant height relative to the reference plane and the second portion has a second constant height relative to the reference plane, wherein the second constant height of the second portion is larger than the first constant height of the first portion.

14. The light directing film according to claim 13 , wherein the first portion has a first cross-sectional shape and the second portion has a second cross-sectional shape, wherein the first cross-sectional shape and the second cross-sectional shape are the same.

15. The light directing film according to claim 14 , wherein each of the first cross-sectional shape and the second cross-sectional shape is a triangle.

16. The light directing film according to claim 13 , wherein the first portion has a first bottom width and the second portion has a second bottom width, wherein the second bottom width is larger than the first bottom width.

17. The light directing film according to claim 13 , wherein the

Assignees

• Ubright Optronics Corp

Inventors

• Wang Kong-Hua
• Lin Craig
• Ko Daniel Yaw-Chung

Classifications

• G02B5/045

  Prism arrays · CPC title

• G02F1/133606

  including a specially adapted diffusing, scattering or light controlling members · CPC title

• G02B6/0053

  Prismatic sheet or layer; Brightness enhancement element, sheet or layer · CPC title

• G02B6/0061

  to provide homogeneous light output intensity · CPC title

• G02B27/1073

  characterized by manufacturing or alignment methods · CPC title