Thin light guiding plate and methods of manufacturing

• US 20090040771A1
• Filed: 08/08/2007
• Published: 02/12/2009
• Est. Priority Date: 08/08/2007
• Status: Abandoned Application

• Current Assignee: SKC Haas Display Films Co., Ltd. (Dow, Inc.)
• Original Assignee: Rohm and Haas Denmark Finance A/S
• Inventors: Aylward, Peter F., Lee, Junwon, Hu, Tseng-En, Landry, Michael R., Lei, Herong, Greener, Jehuda, Anderson, Charles C.
• Application Number:
  US11/890,969
• Publication Number:
  US 20090040771A1
• Time in Patent Office: Days
• US Class Current: 362/330
• 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 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects

Abstract

The present invention provides a composite light guiding plate comprising a light guiding layer comprising an incident face for receiving light from at least one light source, a light guiding output surface that is also generally orthogonal to the incident face, a featured surface, opposite the light-guiding output surface and generally orthogonal to the input face for redirecting light through the light guiding output surface. Further, the featured surface comprises a plurality of rows of linear prismatic structures extended in a length direction that is substantially perpendicular to the incident face and having height and width dimensions of 10 to 200 microns and wherein the length-to-width aspect ratio of the linear prismatic structures is greater than 100:1 the thickness of the light guiding layer is less than 1 mm. Further, the plate is formed from polymeric materials comprising polyesters, amorphous polyesters, polyarylates, polycarbonates, polyamides, polyether-amides, polyamide-imides, polyimides, polyetherimides, cyclic olefin polymers, impact-modified polymethacrylates, polyacrylates, polyacrylonitrile, polystyrenes, polyethers, cellulosics, sulfur-containing polymers and blends or alloys of two or more polymers or copolymers thereof. Additionally, the plate comprises a light extraction layer comprising an input surface having a plurality of protruding light extraction features that have tips that are bonded to the light-guiding output surface of the light guiding layer and provide optical contact between the light guiding and light extraction layers and an illumination output surface for providing light output from the composite illumination plate. Further, the thickness of the light extraction layer is less than 1 mm and wherein one or more channels of air or other gas are sandwiched between the light guiding layer and the light extraction layer.

Claims

1. A composite light guiding plate comprising:

a light guiding layer comprising;

an incident face for receiving light from at least one light source;

a light guiding output surface that is also generally orthogonal to the incident face;

a featured surface, opposite the light-guiding output surface and generally orthogonal to the input face for redirecting light through the light guiding output surface;

wherein the featured surface comprises a plurality of rows of linear prismatic structures extended in a length direction that is substantially perpendicular to the incident face and having height and width dimensions of 10 to 200 microns,

wherein the length-to-width aspect ratio of the linear prismatic structures is greater than 100;

1 the thickness of the light guiding layer is less than 1 mm; and

wherein the plate is formed from polymeric materials comprising polyesters, amorphous polyesters, polyarylates, polycarbonates, polyamides, polyether-amides, polyamide-imides, polyimides, polyetherimides, cyclic olefin polymers, impact-modified polymethacrylates, polyacrylates, polyacrylonitrile, polystyrenes, polyethers, cellulosics, sulfur-containing polymers and blends or alloys of two or more polymers or copolymers thereof; and

a light extraction layer comprising;

an input surface having a plurality of protruding light extraction features that have tips that are bonded to the light-guiding output surface of the light guiding layer and provide optical contact between the light guiding and light extraction layers;

an illumination output surface for providing light output from the composite illumination plate; and

wherein the thickness of the light extraction layer is less than 1 mm and wherein one or more channels of air or other gas are sandwiched between the light guiding layer and the light extraction layer.

2. The composite light guiding plate of claim 1 wherein the polymeric materials comprise amorphous polyesters, polycarbonates, cyclic olefin polymers, impact-modified polymethacrylates, and polymeric materials comprising ester and carbonate moieties.

3. The composite light guiding plate of claim 1 wherein each light extraction feature has a first side comprising two or more planar segments extending in the length direction and a second side comprising two or more planar segments similarly extending in the length direction and wherein the first and second sides intersect at an apex.

4. A method for forming a flexible light guiding plate comprising:

extrusion roll molding a flexible light guiding plate having a featured surface and a light-guiding output surface onto a carrier web;

releasing the light guiding plate from the used carrier web; and

wherein the light guide plate further comprises;

an incident face for receiving light from at least one light source;

an output surface, generally orthogonal to the incident face;

a featured surface generally orthogonal to the incident face for redirecting light through the output surface;

wherein the featured surface comprises a plurality of rows of linear light redirecting structures extended in a length direction that is substantially perpendicular to the incident face, each linear light redirecting structure having height and width dimensions of 10 to 200 microns;

wherein the length-to-width aspect ratio of the linear light redirecting structures is greater than 100;

1 and wherein the light guiding plate has a total thickness less than 1 mm; and

wherein the plate is formed from polymeric materials comprising polyesters, amorphous polyesters, polyarylates, polycarbonates, polyamides, polyether-amides, polyamide-imides, polyimides, polyetherimides, cyclic olefin polymers, impact-modified polymethacrylates, polyacrylates, polyacrylonitrile, polystyrenes, polyethers, cellulosics, sulfur-containing polymers and blends or alloys of two or more polymers or copolymers thereof.

5. The method of claim 4 wherein the polymeric materials comprise amorphous polyesters, polycarbonates, cyclic olefin polymers, impact-modified polymethacrylates and polymeric materials comprising ester and carbonate moieties.

6. A method for forming a composite light guiding plate comprising:

forming a flexible light guiding layer having a featured surface and a light-guiding output surface by extrusion roll molding using a first carrier web;

forming a light extraction layer having an input surface with a plurality of protruding light-extraction features;

bonding protruding ends of the light extraction features of the light extraction layer to the light-guiding output surface of the light guiding layer to form the composite light guiding plate; and

wherein the composite light guiding plate further comprises;

a light guiding layer comprising;

an incident face for receiving light from at least one light source;

a light guiding output surface that is also generally orthogonal to the incident face for directing light outward from the light guiding layer;

a featured surface, opposite the light-guiding output surface and generally orthogonal to the input face for redirecting light through the light guiding output surface;

wherein the featured surface comprises a plurality of rows of linear prismatic structures extended in a length direction that is substantially perpendicular to the incident face and having height and width dimensions of 10 to 200 microns,

wherein the length-to-width aspect ratio of the linear prismatic structures is greater than 100;

1 the thickness of the light guiding layer is less than 1 mm; and

wherein the plate is formed from polymeric materials comprising polyesters, amorphous polyesters, polyarylates, polycarbonates, polyamides, polyether-amides, polyamide-imides, polyimides, polyetherimides, cyclic olefin polymers, impact-modified polymethacrylates, polyacrylates, polyacrylonitrile, polystyrenes, polyethers, cellulosics, sulfur-containing polymers and blends or alloys of two or more polymers or copolymers thereof; and

a light extraction layer comprising;

an input surface having a plurality of protruding light extraction features that have tips that are bonded to the light-guiding output surface of the light guiding layer and provide optical contact between the light guiding and light extraction layers;

an illumination output surface for providing light output from the composite light guiding plate; and

wherein the thickness of the light extraction layer is less than 1 mm and wherein one or more channels of air or other gas are sandwiched between the light guiding layer and the light extraction layer.

7. The method of claim 6 wherein the polymeric materials comprise amorphous polyesters, polycarbonates, cyclic olefin polymers, impact-modified polymethacrylates and polymeric materials comprising ester and carbonate moieties.

8. The method of claim 6 wherein bonding uses an adhesive.