Variable index light extraction layer and method of making the same

Patent metadata

Field	Value
Publication number	US-10139550-B2
Application number	US-201314423654-A
Country	US
Kind code	B2
Filing date	Aug 21, 2013
Priority date	Aug 24, 2012
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

Variable index light extraction layers that contain a first region with a first material and a second region including a second material are described, where the first region has a lower effective index of refraction than the second region. Optical films and stacks may use the variable index light extraction layers in front lit or back lit display devices and luminaires.

First claim

What is claimed is:

1. A method of forming a variable index extraction layer, comprising
patterning a first substance on a substrate and overcoating a second substance to form a layer;
wherein first regions of the layer correspond to areas where the first substance was selectively printed and second regions of the layer correspond at least to areas between where the first substance was selectively printed;
wherein the first region has a lower effective index of refraction than the second region;
wherein a difference between an effective index of refraction of the first region and an effective index of refraction of the second region is greater than about 0.03;
wherein the first substance is a nanovoided polymeric material;
wherein the second substance is not a nanovoided polymeric material; and
wherein the first and second regions of the layer are disposed such that the layer selectively extracts guided mode light from the substrate based on the geometric arrangement of the first and second regions.

2. The method of claim 1 , further comprising forming a plurality of optical microstructures on a major surface of the layer opposite the substrate.

3. The method of claim 2 , wherein forming a plurality of optical microstructures of a major surface of the layer opposite the substrate uses a cast and cure method.

4. The method of claim 2 , wherein the plurality of optical microstructures is a diffractive surface.

5. The method of claim 1 , wherein patterning a first substance on a substrate uses flexographic printing.

6. The method of claim 1 , wherein patterning a first substance on a substrate uses indirect gravure printing.

7. The method of claim 1 , wherein patterning a first substance on a substrate uses direct gravure printing.

8. The method of claim 1 , wherein patterning a first substance on a substrate uses inkjet printing.

Assignees

• 3M Innovative Properties Co

Inventors

• Thompson David Scott
• Dodds Shawn C
• Pekurovsky Mikhail L
• Schaffer Kevin R
• Stay Matthew S
• Solomonson Steven D
• Wheatley John A
• Yang Zhaohui
• Woody V Joseph W

Classifications

• G02B6/0043 Primary

  provided on the surface of the light guide · CPC title

• G02B6/0055

  Reflecting element, sheet or layer · CPC title

• G02B6/0065

  Manufacturing aspects; Material aspects · CPC title

• G02B6/0063 Primary

  for extracting light out both the major surfaces of the light guide · CPC title

• G02B6/005

  provided by one optical element, or plurality thereof, placed on the light output side of the light guide · CPC title