Wide-area solid-state illumination devices and systems

Patent metadata

Field	Value
Publication number	US-11079533-B2
Application number	US-202016780872-A
Country	US
Kind code	B2
Filing date	Feb 3, 2020
Priority date	Sep 9, 2017
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

Wide-area solid-state illumination devices and systems employing a thin and flexible sheet of an optically transmissive material having at least one broad-area surface patterned with light scattering surface microstructures such as microdots of a non-absorbing UV curable ink. Light is input into the thin and flexible sheet using a number of compact solid-state light sources, such as LEDs, optically coupled to one or more edges or to one or two of the broad-area surfaces defining the thin and flexible sheet. Each surface microstructure forms a semi-opaque layer that extracts light from the thin and flexible sheet and causes light emission from both opposing broad-area surfaces of the sheet.

First claim

What is claimed is:

1. An illumination system, comprising:
a thin and flexible sheet of an optically transmissive material having a first broad-area surface, an opposing second broad-area surface extending parallel to the first broad-area surface, a first edge, and an opposing second edge;
a first plurality of compact solid-state light sources optically coupled to the first edge; and
a two-dimensional pattern of first discrete light extraction features formed on the first broad-area surface with variable spacing, at least one of the first discrete light extraction features comprising a semi-opaque layer of a light scattering material,
wherein the light scattering material comprises an optically transmissive binder material and submicron-sized particles embedded into the binder material and having a greater refractive index than the binder material, wherein the semi-opaque layer has a variable thickness characterized by a curved cross-sectional profile, and wherein a ratio between a longest dimension of said at least one of the first discrete light extraction features and a maximum thickness of the semi-opaque layer is greater than 5.

2. An illumination system as recited in claim 1 , wherein said at least one of the first discrete light extraction features has a size between 10 micrometers and 200 micrometers along a longest dimension and a total volume between 1,000 cubic micrometers to 100,000 cubic micrometers, and wherein the maximum thickness is between 1 and 15 micrometers.

3. An illumination system as recited in claim 1 , further comprising a two-dimensional pattern of second discrete light extraction features formed on the first broad-area surface, at least some of the second discrete light extraction features being located in spaces between the first discrete light extraction features, wherein at least one of the second discrete light extraction features comprises a semi-opaque layer of a light scattering material and has a much smaller size than said at least one of the first discrete light extraction features.

4. An illumination system as recited in claim 1 , further comprising a two-dimensional pattern of second discrete light extraction features formed in the second broad-area surface, wherein at least one of the second discrete light extraction features comprises a semi-opaque layer of a light scattering material disposed in optical contact with the second broad-area surface and configured for extracting light from the thin and flexible sheet.

5. An illumination system as recited in claim 1 , wherein an opacity of the semi-opaque layer is between 30% and 70%.

6. An illumination system as recited in claim 1 , wherein a surface of the semi-opaque layer comprises surface microstructures and is characterized by an RMS surface roughness parameter having values greater than 30 nanometers and less than 0.5 micrometers.

7. An illumination system as recited in claim 1 , wherein the two-dimensional pattern has a plurality of patterned areas alternating with a plurality of separation areas being substantially free from the first discrete light extraction features, and wherein at least one of the separation areas is configured as a continuous strip or band having a width that is greater than a prevalent spacing distance between the first discrete light extraction features in an adjacent patterned area.

8. An illumination system as recited in claim 1 , wherein the two-dimensional pattern has a plurality of patterned areas alternating with a plurality of separation areas being substantially free from the first discrete light extraction features, and wherein at least one of the separation areas has a width that is at least 10 times greater than a prevalent spacing distance between the first discrete light extraction features in an adjacent patterned area.

9. An illumination system as recited in claim 1 , wherein at least one of the first discrete light extraction features comprises a fluorescent material.

10. An illumination system as recited in claim 1 , wherein a concentration of the submicron-sized particles in the binder material is 5-30% by weight, and wherein a size of at least some of the submicron-sized particles is between 100 nanometers and 400 nanometers.

11. An illumination system as recited in claim 1 , wherein said at least one of the first discrete light extraction features has an irregular elongated shape.

12. An illumination system as recited in claim 1 , wherein said at least one of the first discrete light extraction features is disposed in contact or substantially overlaps with a second one of the first discrete light extraction features.

13. An illumination system as recited in claim 1 , wherein the first discrete light extraction features include individual ones having regular shapes and individual ones having irregular shapes.

14. An illumination system as recited in claim 1 , further comprising a second plurality of compact solid-state light sources configured to emit light in a different color than the first plurality of compact solid-state light sources.

15. An illumination system, comprising:
a thin and flexible sheet of an optically transmissive material having a first broad-area surface, an opposing second broad-area surface extending parallel to the first broad-area surface, a first edge, and an opposing second edge;
a plurality of compact solid-state light sources optically coupled to the first edge; and
a two-dimensional pattern of discrete light extraction features formed on the first broad-area surface,
wherein at least one of the light extraction features comprises an inner layer of a partially optically transmissive material, which has a variable thickness with a curved cross-sectional profile, and an outer opaque layer of a light absorbing material conformably coating the inner layer of a partially optically transmissive material.

16. An illumination system as recited in claim 15 , wherein a maximum thickness of the inner layer is at least 5 times less than a longest dimension of said at least one of the light extraction features, and wherein an area defined by a perimeter of the outer opaque layer is greater than an area defined by a perimeter of the inner layer by at least 5%.

17. An illumination system as recited in claim 15 , comprising an image print attached to or positioned in a proximity to the said second broad-area surface.

Assignees

• Vasylyev Sergiy
• Masalitin Mykola
• S V V Tech Innovations Inc

Inventors

• Vasylyev Sergiy
• Masalitin Mykola

Classifications

• G02B6/0076

  Stacked arrangements of multiple light guides of the same or different cross-sectional area · CPC title

• G02B6/0065

  Manufacturing aspects; Material aspects · CPC title

• G02B6/0043 Primary

  provided on the surface of the light guide · CPC title

• G02B6/0061

  to provide homogeneous light output intensity · CPC title

• G02B6/0036

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