Integral multilayer optical film

Patent metadata

Field	Value
Publication number	US-12001099-B2
Application number	US-202218080069-A
Country	US
Kind code	B2
Filing date	Dec 13, 2022
Priority date	Dec 16, 2021
Publication date	Jun 4, 2024
Grant date	Jun 4, 2024

Abstract

An integral multilayer optical construction includes opposing first and second structured major surfaces having two-dimensional arrays of respective first and second structures. An optical diffuser is embedded within the optical construction between the first and second structured major surfaces. The optical diffuser has an optical haze of greater than about 5% for at least one visible wavelength in a visible wavelength range extending from about 420 nm to 680 nm. When the optical construction is disposed on a light source with one of the first and second structured major surfaces facing the light source, light emitted by the light source is transmitted by the optical construction with a cross-section of an angular luminous distribution of the transmitted light in at least one first plane that includes a normal to the optical construction, including first and second intensity peaks at respective first and second angles on opposite sides of the normal.

First claim

The invention claimed is:

1. An integral multilayer optical construction comprising:
opposing first and second structured major surfaces comprising substantially regular two-dimensional arrays of respective first and second structures arranged thereacross; and
at least a first embedded optical diffuser embedded within the optical construction between, and spaced apart from, the first and second structured major surfaces, the first embedded optical diffuser having an optical haze of greater than about 5% for at least one visible wavelength in a visible wavelength range extending from about 420 nm to about 680 nm,
such that when the optical construction is disposed on a substantially Lambertian light source with one of the first and second structured major surfaces facing the Lambertian light source, light emitted by the Lambertian light source is transmitted by the optical construction with a cross-section of an angular luminous distribution of the transmitted light in at least one first plane that comprises a normal to the optical construction, comprising first and second intensity peaks at respective first and second angles on opposite sides of the normal, wherein the multilayer optical construction has an integral construction;
wherein in the at least one first plane, the angular luminous distribution of the transmitted light has a global maximum that makes an angle of greater than about 20 degrees with the normal and a global minimum that makes an angle of less than about 10 degrees with the normal.

2. The integral multilayer optical construction of claim 1 , wherein a magnitude of a difference between an intensity of the global maximum and an intensity of the global minimum is greater than about 20%.

3. The integral multilayer optical construction of claim 1 , wherein the global maximum makes an angle of less than about 85 degrees with the normal.

4. The integral multilayer optical construction of claim 1 , wherein the first intensity peak is a global maximum on one of side of the normal and the second intensity peak is a global maximum on the other side of the normal.

5. The integral multilayer optical construction of claim 1 , wherein the at least the first embedded optical diffuser comprises the first and a second embedded optical diffusers embedded within the optical construction between, and spaced apart from, the first and second structured major surfaces, wherein, the first and second embedded optical diffusers are spaced apart from each other along a thickness direction of the optical construction, and wherein the second embedded optical diffuser has an optical haze of greater than about 2% for at least one visible wavelength in a visible wavelength range extending from about 420 nm to about 680 nm.

6. The integral multilayer optical construction of claim 1 , wherein when the optical construction is illuminated with a light source, the optical construction has an average effective transmission T 1 , and when a comparative integral multilayer optical construction that comprises substantially a same construction except that it does not include the at least the first embedded optical diffuser, is illuminated with the light source, the comparative optical construction has an average effective transmission T 2 , T 1 greater than T 2 by at least 0.5%.

7. The integral multilayer optical construction of claim 1 , wherein each of the first and second structures comprises at least two facets meeting at a peak of the structure, the peak having a radius of curvature, wherein the radius of curvatures of the peaks of the first structures are different than the radius of curvatures of the peaks of the second structures by at least a factor of 2.

8. A display system comprising:
a plurality of light emitting sources configured to emit light and disposed on a reflective substrate having an optical reflectance of greater than about 30% at at least one visible wavelength;
a display panel disposed on the light emitting sources and configured to receive the emitted light and form an image;
a reflective polarizer disposed between the display panel and the light emitting sources, such that for a substantially normally incident light and for at least the at least one visible wavelength, the reflective polarizer reflects at least 60% of the incident light having an in-plane first polarization state, and transmits at least 60% of the incident light having an orthogonal in-plane second polarization state; and
the integral multilayer optical construction of claim 1 disposed between the reflective polarizer and the light emitting sources.

9. The display system of claim 8 further comprising first and second prismatic films disposed between the reflective polarizer and the integral multilayer optical construction, each of the prismatic films comprising a plurality of linear prismatic structures extending along a longitudinal direction and arranged along an orthogonal lateral direction, such that an angle between the longitudinal directions of the first and second prismatic films is greater than about 30 degrees.

10. The display system of claim 8 , wherein the at least the first embedded optical diffuser comprises the first and a second embedded optical diffusers embedded within the optical construction between, and spaced apart from, the first and second structured major surfaces, wherein, the first and second embedded optical diffusers are spaced apart from each other along a thickness direction of the optical construction, and wherein the second embedded optical diffuser has an optical haze of greater than about 2% for at least one visible wavelength in a visible wavelength range extending from about 420 nm to about 680 nm.

11. The display system of claim 8 , wherein the first and second structures comprise respective pluralities of first and second peaks, the first peaks sharper than the second peaks, the first peaks facing the plurality of light emitting sources, the second peaks facing away from the plurality of light emitting sources.

12. The integral multilayer optical construction of claim 8 , wherein the first structures are arranged along at least a first direction at an average pitch P 1 and the second structures are arranged along at least a second direction (x-axis) at an average pitch P 2 , and wherein P 1 /P 2 ≤3.

13. The integral multilayer optical construction of claim 8 , wherein the first structures form parallel rows of first structures extending along a first direction and the second structures form parallel rows of second structures extending along a second direction, and wherein the first and second directions form an angle of greater than about 5 degrees and less than about 85 degrees therebetween.

14. The integral multilayer optical construction of claim 8 , wherein the angle between the first and second directions is greater than about 70 degrees and less than about 85 degrees.

15. The integral multilayer optical construction of claim 8 further comprising a light converting material disposed between the opposing first and second structured major surfaces and configured to receive a first light having a first wavelength and, in response, emit a second light having one or more different second wavelengths.

16. The integral multilayer optical construction of claim 15 , wherein the first wavelength is less than about 420 nm and the one or more different second wavelengths are greater than about 420 nm.

17. An integral multilayer optical construction comprising:
opposing first and second structured major surfaces comprising substantially regular two-dimensional arrays of respectiv

Assignees

• 3M Innovative Properties Company

Inventors

• Boyd Gary T
• Fan Shu-Ching
• Pongratz Alex P
• Gaides Gary E

Classifications

• G02F1/133607 Primary

  the light controlling member including light directing or refracting elements, e.g. prisms or lenses · CPC title

• G02F1/133611

  including means for improving the brightness uniformity · CPC title

• G02F1/13362

  providing polarized light, e.g. by converting a polarisation component into another one · CPC title

• G02F1/133504 Primary

  Diffusing, scattering, diffracting elements (associated to illuminating devices G02F1/133606) · CPC title

• G02F1/133603

  with LEDs · CPC title