Brightness enhancement film using an array of light concentrators

• US 7,581,867 B2
• Filed: 07/10/2006
• Issued: 09/01/2009
• Est. Priority Date: 06/03/2004
• Status: Expired due to Fees

• Current Assignee: SKC Haas Display Films Co., Ltd. (Dow, Inc.)
• Original Assignee: SKC Haas Display Films Co., Ltd. (Dow, Inc.)
• Inventors: Kessler, David, Lee, Junwon
• Primary Examiner(s): Alavi; Ali
• Application Number:
  US11/483,830
• Publication Number:
  US 20060250819A1
• Time in Patent Office: 1,149 Days
• Field of Search: 362606-607, 362/331, 362612-613, 362617-620
• US Class Current: 362/620
• CPC Class Codes: G02B 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects

Abstract

A brightness enhancement article and illumination system provides light from a two-dimensional surface. The brightness enhancement article has a plurality of light collecting structures wherein each light collecting structure is longitudinally extended in a length direction along the surface. The structures may have various lengthwise shapes such as being curved, concentric, radial, or of varying thickness.

Claims

1. A brightness enhancement article for providing light from a light guiding plate surface, the brightness enhancement article comprising a plurality of light collecting structures, wherein adjacent light collecting structures are arranged to vary their direction along their length on the light-providing light guiding plate surface, each light collecting structure comprising:

(a) an input aperture optically coupled to the light-providing surface;

(b) an output aperture distal from said input aperture, wherein the output aperture has a surface area that is larger than the surface area of the input aperture and wherein the width of the output aperture varies over the length of the light collecting structure alone the light guiding plate surface; and

,

(c) a pair of curved side walls extending along the length direction and extended from the output aperture toward the input aperture;

wherein, in a cross section taken orthogonally with respect to the length direction, the curved side walls approximate a parabolic curvature.

2. The brightness enhancement article according to claim 1 wherein adjacent light collecting structures are arranged to follow concentric circular paths on the light-providing light guiding plate surface.

3. The brightness enhancement article according to claim 1 wherein light collecting structures are arranged to follow curved paths with dimensional modifications along the length thereof on the light guiding plate surface.

4. The brightness enhancement article according to claim 1 wherein the light guiding plate surface and at least one light collecting structure have the same refractive index.

5. The brightness enhancement article according to claim 1 wherein the pitch between adjacent light collecting structures is substantially equal.

6. The brightness enhancement article according to claim 1 wherein the curved side walls of the light collecting structure between the input and output aperature provide total internal reflection to direct light incident at the input aperture to the output aperture.