Lightguide

Patent metadata

Field	Value
Publication number	US-9684119-B2
Application number	US-201414537308-A
Country	US
Kind code	B2
Filing date	Nov 10, 2014
Priority date	Aug 12, 2009
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

Flexible unitary lightguide and a method of making the same are disclosed. The lightguide includes a structured input side that includes a first pattern having smaller features superimposed on a second pattern having larger features. The lightguide further includes a structured top surface that includes a first region and a different second region. The first region includes a plurality of discrete light extractors for extracting light that propagates within the flexible unitary lightguide by total internal reflection. The second region includes a taper portion for directing light from the structured input side to the first region. The light extractors form a periodic array that has a first period along the length of the flexible unitary lightguide. The first period is such that substantially no visible moire fringes occur when the flexible unitary lightguide is used as a backlight in a pixelated display.

First claim

What is claimed is:

1. A method of fabricating a lightguide comprising the steps of:
(a) providing a first tool;
(b) forming a patterned first tool by:
(i) patterning a first region of the first tool using a first patterning method to form a first patterned region; and
(ii) patterning a second region of the first tool, different than the first region of the first tool, using a second patterning method different than the first patterning method to form a second patterned region;

(c) replicating the patterned first tool into a lightguide material to form a lightguide comprising a first replicated region corresponding to the first patterned region of the patterned first tool and a second replicated region corresponding to the second patterned region of the patterned first tool; and
(d) cutting the lightguide to form a structured input side comprising a first pattern having smaller features superimposed on a second pattern comprising larger features.

2. The method of claim 1 , wherein the first patterning method comprises an engraving method and the second patterning method comprises a thread cutting method.

3. The method of claim 1 , wherein the lightguide material is liquid.

4. The method of claim 1 , wherein a temperature of the lightguide material is greater than a glass transition temperature of the lightguide material.

5. The method of claim 1 , wherein the lightguide material is molten.

6. The method of claim 1 , wherein the lightguide material physically contacts an outermost surface of the patterned first tool.

7. The method of claim 1 , wherein the step of replicating the patterned first tool into a lightguide material comprises disposing the lightguide material in between the first tool and a second tool.

8. The method of claim 7 , wherein the lightguide material physically contacts an outermost surface of the second tool.

9. The method of claim 7 , wherein the second tool comprises a smooth outermost surface resulting in the lightguide having a smooth bottom surface.

10. The method of claim 7 , wherein the second tool comprises a structured outermost surface resulting in the lightguide having a structured bottom surface.

11. The method of claim 10 , wherein the structured bottom surface of the lightguide prevents wet out.

12. The method of claim 1 , wherein the step of cutting the lightguide comprises cutting the lightguide by a die cutting or a laser cutting method.

Assignees

• 3M Innovative Properties Co

Inventors

• Solomon Jeffrey L
• Kinder Brian A
• Boyd Gary T

Classifications

• C03B11/082

  having profiled, patterned or microstructured surfaces · CPC title

• G02B6/0088

  of the light guide or other optical sheets in the package · CPC title

• B29D11/0074

  Production of other optical elements not provided for in B29D11/00009- B29D11/0073 · CPC title

• G02B6/0036 Primary

  2-D arrangement of prisms, protrusions, indentations or roughened surfaces · CPC title

• G02B6/0028

  Light guide, e.g. taper · CPC title