Light control film including optical cavities containing liquid

Patent metadata

Field	Value
Publication number	US-12596209-B2
Application number	US-202318303276-A
Country	US
Kind code	B2
Filing date	Apr 19, 2023
Priority date	Apr 29, 2022
Publication date	Apr 7, 2026
Grant date	Apr 7, 2026

Abstract

A light control film includes a plurality of substantially parallel optical cavities. Each of the optical cavities has a height H along a thickness direction of the light control film and a minimum lateral dimension W along an in-plane width direction orthogonal to the thickness direction, where H≥W. The optical cavities are substantially filled with a liquid including a plurality of light absorbing particles configured to move along the thickness direction in response to one or more applied signals or fields such that the movement along the thickness direction causes each of the optical cavities to transition between a substantially opaque state and a substantially transparent state. A full viewing angle of the light control film increases when the optical cavities transition from the substantially opaque state to the substantially transparent state.

First claim

What is claimed is:

1 . A light control film comprising a plurality of substantially parallel optical cavities, each of the optical cavities having a height H along a thickness direction of the light control film and a minimum lateral dimension W along an in-plane width direction orthogonal to the thickness direction, H≥W, the optical cavities substantially filled with a liquid comprising a plurality of light absorbing particles configured to move along the thickness direction in response to one or more applied signals or fields such that the movement along the thickness direction causes each of the optical cavities to transition between a substantially opaque state and a substantially transparent state, wherein a full viewing angle of the light control film increases when the optical cavities transition from the substantially opaque state to the substantially transparent state,
wherein the light control film comprises first and second optical components comprising respective first and second unitary elements, the first and second unitary elements comprising respective first and second polymeric layers and respective pluralities of first and second structures formed on, and extending from, the respective first and second polymeric layers, the first and second optical components assembled so that the first and second structures are disposed between the first and second polymeric layers and interleaved to form a plurality of pairs of adjacent first and second structures, wherein each optical cavity of the plurality of optical cavities is defined between a pair of adjacent first and second structures.

2 . The light control film of claim 1 , wherein the one or more applied signals or fields comprises one or more electrical signals.

3 . The light control film of claim 1 further comprising a first substantially transparent electrically conductive layer disposed on a first side of the plurality of substantially parallel optical cavities.

4 . The light control film of claim 3 further comprising a second substantially transparent electrically conductive layer disposed on a second side of the plurality of substantially parallel optical cavities opposite the first side, the first and second substantially transparent electrically conductive layers substantially coextensive with one another.

5 . The light control film of claim 3 further comprising a plurality of electrically conductive ribbons disposed on a second side of the plurality of substantially parallel optical cavities opposite the first side, the ribbons extending along a length direction orthogonal to the width and thickness directions and being arranged along the width direction such that the ribbons are aligned with the optical cavities in one-to-one correspondence.

6 . The light control film of claim 1 , wherein the particles are electrically charged.

7 . The light control film of claim 1 , wherein the full viewing angle of the light control film increases by at least about 30 degrees when the optical cavities transition from the substantially opaque state to the substantially transparent state.

8 . The light control film of claim 1 , wherein the first and second optical components comprise respective first and second substrates, the first and second substrates comprising the respective first and second polymeric layers and further comprising respective first and second substantially transparent electrically conductive layers, the first and second polymeric layers disposed between the first and second substantially transparent electrically conductive layers.

9 . A light control film comprising a plurality of substantially parallel optical cavities, each of the optical cavities having a height H along a thickness direction of the light control film and a minimum lateral dimension W along an in-plane width direction orthogonal to the thickness direction, H≥W, each of the optical cavities substantially filled with a liquid comprising a plurality of light absorbing particles substantially uniformly dispersed therein so that the optical cavity has a first optical absorption along the width direction of the optical cavity at at least a first location along the thickness direction of the optical cavity, such that in response to a first electrical signal at least a majority of the light absorbing particles in the liquid move to one or more predetermined locations within the optical cavity resulting in the optical cavity having a second optical absorption along the width direction of the optical cavity at the at least the first location along the thickness direction, the second optical absorption smaller than the first optical absorption,
wherein the light control film comprises first and second optical components comprising respective first and second unitary elements, the first and second unitary elements comprising respective first and second polymeric layers and respective pluralities of first and second structures formed on, and extending from, the respective first and second polymeric layers, the first and second optical components assembled so that the first and second structures are disposed between the first and second polymeric layers and interleaved to form a plurality of pairs of adjacent first and second structures, wherein each optical cavity of the plurality of optical cavities is defined between a pair of adjacent first and second structures.

10 . The light control film of claim 9 , wherein each optical cavity extends along the thickness direction between opposing ends of the optical cavity, the one or more predetermined locations comprising a location adjacent one of the opposing ends.

11 . The light control film of claim 10 , wherein the first location is disposed about halfway between the opposing ends.

12 . The light control film of claim 9 , wherein the light absorbing particles comprise electrically charged particles and the liquid comprises a continuous phase comprising a non-polar liquid.

13 . The light control film of claim 9 , wherein the first and second optical components comprise respective first and second substrates, the first and second substrates comprising the respective first and second polymeric layers and further comprising respective first and second substantially transparent electrically conductive layers, the first and second polymeric layers disposed between the first and second substantially transparent electrically conductive layers.

14 . The light control film of claim 9 , wherein a full viewing angle of the light control film increases by at least about 30 degrees when the light absorbing particles move from being substantially uniformly dispersed in the liquid to the one or more predetermined locations.

15 . A light control film extending along orthogonal length and width directions of the light control film, the light control film comprising a plurality of optical cavities arranged along the width direction, each of the optical cavities extending along the length direction and along a thickness direction of the light control film orthogonal to the length and width directions, each of the optical cavities having a height H along the thickness direction and a width W along the width direction, H≥W, the optical cavities substantially filled with a liquid comprising a plurality of light absorbing particles configured to move translationally in response to one or more applied signals or fields such that the translational movement causes each of the optical cavities to transition between a substantially opaque state and a substantially transparent state, wherein a full viewing angle of the light control film increases when the

Assignees

• 3M Innovative Properties Company

Inventors

• Gotrik Kevin W
• Etzkorn Stephen J
• Johnson Nicholas A
• Liu Tao
• Sullivan John J
• Acharya Bharat R

Classifications

• G02F1/153

  Constructional details · CPC title

• G02B2207/123

  Optical louvre elements, e.g. for directional light blocking · CPC title

• G02B5/003 Primary

  Light absorbing elements · CPC title