Optical system including light control film and fresnel lens

Patent metadata

Field	Value
Publication number	US-12004410-B2
Application number	US-202017768421-A
Country	US
Kind code	B2
Filing date	Oct 29, 2020
Priority date	Nov 8, 2019
Publication date	Jun 4, 2024
Grant date	Jun 4, 2024

Abstract

An optical system includes a light source, an optical film curved about a first axis, and a light control film curved about the first axis and disposed between the light source and the optical film. The optical film includes a microstructured first major surface and an opposing second major surface. The microstructured first major surface defines a linear Fresnel lens including a plurality of Fresnel elements extending longitudinally along the first axis. The first major surface of the optical film faces the light control film. The light control film includes a plurality of alternating optically transmissive and optically absorptive regions extending longitudinally along the first axis such that in a cross-section orthogonal to the first axis, for at least a majority of the optically transmissive regions, a centerline between adjacent optically absorptive regions is substantially normal to a major surface of the light control film.

First claim

What is claimed is:

1. An optical system comprising:
a light source;
an optical film curved about a first axis and comprising a microstructured first major surface and an opposing second major surface, the microstructured first major surface defining a linear Fresnel lens comprising a plurality of Fresnel elements extending longitudinally along the first axis; and
a light control film curved about the first axis and disposed between the light source and the optical film, the first major surface of the optical film facing the light control film, the light control film comprising a plurality of alternating optically transmissive and optically absorptive regions extending longitudinally along the first axis such that in a cross-section orthogonal to the first axis, for at least a majority of the optically transmissive regions, a centerline between adjacent optically absorptive regions is substantially normal to a major surface of the light control film.

2. The optical system of claim 1 , wherein the light source comprises a backlight.

3. The optical system of claim 2 , wherein the backlight comprises a light guide curved about the first axis.

4. The optical system of claim 2 further comprising a display panel disposed between the backlight and the light control film.

5. The optical system of claim 1 further comprising a display panel, the optical film disposed between the display panel and the light control film.

6. The optical system of claim 1 , wherein the light source comprises an organic light emitting diode (OLED) display curved about the first axis.

7. The optical system of claim 1 , wherein the plurality of Fresnel elements comprises a plurality of polymeric Fresnel elements at least partially coated with an inorganic optically transparent layer.

8. The optical system of claim 7 , wherein each Fresnel element comprises an optical facet and a sidewall meeting the optical facet at a ridge of the Fresnel element, wherein for each Fresnel element in at least a majority of the Fresnel elements, an optically absorptive layer is disposed on and substantially covers the inorganic optically transparent layer disposed on the sidewall.

9. The optical system of claim 1 , wherein an airgap separates at least a majority of the first major surface of the optical film from the light control film.

10. The optical system of claim 1 , wherein the optical film and the light control film are taped to one another along at least an edge of the optical film and corresponding edge of the light control film.

11. The optical system of claim 1 , wherein the first major surface of the optical film comprises a plurality of elongated spacer members extending toward the light control film and being received by an adhesive layer disposed on the light control film.

12. The optical system of claim 1 , further comprising:
a low index layer disposed on and contacting at least a majority of the first major surface of the optical film, the low index layer having a refractive index of no more than 1.45; and
an optical adhesive bonding the low index layer to the light control film.

13. An optical system comprising:
an optical film curved about a first axis and comprising a microstructured first major surface and an opposing second major surface, the microstructured first major surface defining a linear Fresnel lens comprising a plurality of Fresnel elements extending longitudinally along the first axis, each Fresnel element comprising an optical facet and a sidewall meeting the optical facet at a ridge of the Fresnel element, wherein for each Fresnel element in at least a majority of the Fresnel elements, an optically absorptive layer is disposed on and substantially covers the sidewall, the optically absorptive layer having an average thickness t, 100 nm<t<1 micrometer;
a light control film curved about the first axis and disposed proximate the optical film, the first major surface of the optical film facing the light control film, the light control film comprising a plurality of alternating optically transmissive and optically absorptive regions extending longitudinally along the first axis such that in a cross-section orthogonal to the first axis, for at least a majority of the optically transmissive regions, a centerline between adjacent optically absorptive regions is substantially normal to a major surface of the light control film.

14. The optical system of claim 13 , wherein for each Fresnel element in at least the majority of the Fresnel elements, the sidewall of the Fresnel element has a height H from a base of an adjacent Fresnel element to the ridge of the Fresnel element, H/t>15.

15. The optical system of claim 13 , wherein the plurality of Fresnel elements has an extinction coefficient k 0 <0.05, and wherein for each Fresnel element in at least the majority of the Fresnel elements, a first layer is disposed between the sidewall and the optically absorptive layer, the first layer having an extinction coefficient k 1 >k 0 , the optically absorptive layer having an extinction coefficient k 2 , wherein k 2 −k 1 >0.05.

Assignees

• 3M Innovative Properties Company

Inventors

• Liu Tao
• Boyd Gary T
• Schmidt Daniel J
• Nelson Caleb T
• Anderson Owen M
• Pham Tri D
• Hao Encai
• Fan Shu-Ching

Classifications

• H10K59/879 Primary

  comprising refractive means, e.g. lenses · CPC title

• G02B3/08 Primary

  with discontinuous faces, e.g. Fresnel lens {(diffractive Fresnel lenses G02B5/1876)} · CPC title

• G02B5/003 Primary

  Light absorbing elements · CPC title

• G02B5/0263

  with positional variation of the diffusing properties, e.g. gradient or patterned diffuser · CPC title

• G02B5/208

  for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation · CPC title