Light Control Film and Method of Fabricating Same

Patent metadata

Field	Value
Publication number	US-2025271605-A1
Application number	US-202318857872-A
Country	US
Kind code	A1
Filing date	Apr 24, 2023
Priority date	May 6, 2022
Publication date	Aug 28, 2025
Grant date	—

Abstract

A light control film has opposing substantially planar substantially parallel first and second major surfaces spaced apart along a thickness direction of the light control film, and a plurality of substantially parallel optically transparent polymeric columns disposed in, and substantially surrounded by, a light absorbing polymeric material. Each of the polymeric columns has a first column end at the first major surface and an opposite second column end at the second major surface, such that the first column ends are arranged to define a plurality of substantially parallel alternating substantially linear rows of the first column ends and substantially linear rows of continuous light absorbing polymeric material. Methods of fabricating the light control film are described.

First claim

1 - 15 . (canceled)

16 . A light control film comprising:
opposing substantially planar substantially parallel first and second major surfaces spaced apart along a thickness direction of the light control film by less than about 500 microns; and a plurality of substantially parallel optically transparent polymeric columns disposed in, and substantially surrounded by, a light absorbing polymeric material, each of the polymeric columns having a first column end at the first major surface and an opposite second column end at the second major surface, each of the polymeric columns having an aspect ratio of greater than about 3, such that the first column ends are arranged to define a plurality of substantially parallel alternating substantially linear rows of the first column ends and substantially linear rows of continuous light absorbing polymeric material, wherein for each pair of a plurality of adjacent first column ends, the adjacent first column ends are nested and separated by the light absorbing polymeric material.

17 . The light control film of claim 16 , wherein the rows of continuous light absorbing polymeric material are thinner than the rows of first column ends.

18 . The light control film of claim 16 , wherein the first column ends of each row of first column ends are separated by light absorbing polymeric material.

19 . The light control film of claim 16 , wherein for each pair of the plurality of adjacent polymeric columns, the adjacent polymeric columns have adjacent sides facing each other and concave toward a same direction.

20 . The light control film of claim 16 , wherein the polymeric columns have an in-plane aspect ratio of less than 5.

21 . The light control film of claim 16 , wherein the plurality of first column ends is more periodic along a first direction and less periodic along a second direction substantially orthogonal to the first direction.

22 . The light control film of claim 16 , wherein the first column ends define a plurality of substantially parallelogram shapes arranged into a plurality of substantially parallel substantially linear rows, wherein at least some of the substantially parallelogram shapes have no right angles.

23 . The light control film of claim 22 , wherein at least 50 percent of the substantially parallelogram shapes have no right angles.

24 . The light control film of claim 22 , wherein at least 70 percent of the substantially parallelogram shapes have no right angles.

25 . The light control film of claim 16 , wherein for a substantially collimated incident light having a wavelength in a wavelength range from about 400 nm to about 2000 nm, an optical transmittance of the light control film versus an incident angle of the incident light in a first incident plane has a peak transmittance of greater than about 2% with a corresponding first full width at half maximum (FWHM) of between about 5 degrees and about 120 degrees.

26 . The light control film of claim 25 , wherein an optical transmittance of the light control film versus an incident angle of the incident light in a second incident plane different from the first incident plane has a transmitted peak with a corresponding second FWHM different from the first FWHM by at least about 10%.

27 . A light control film comprising:
opposing substantially planar substantially parallel first and second major surfaces spaced apart along a thickness direction of the light control film by less than about 750 microns; and a plurality of substantially parallel optically transparent polymeric columns disposed in, and substantially surrounded by, a light absorbing polymeric material, each of the polymeric columns having a first column end at the first major surface and an opposite second column end at the second major surface, each of the polymeric columns having an aspect ratio of greater than about 3, such that the first column ends of at least one pair of adjacent first and second polymeric columns comprise respective first and second non-straight sides facing one another to define substantially complementary shapes, wherein the polymeric columns are arranged to define a plurality of substantially parallel alternating substantially planar rows of the columns and substantially planar rows of continuous light absorbing polymeric material.

28 . The light control film of claim 27 , wherein for each pair of a plurality of adjacent polymeric columns, the adjacent polymeric columns are nested and separated by the light absorbing polymeric material.

29 . The light control film of claim 27 , wherein for a substantially collimated incident light having a wavelength in a wavelength range from about 400 nm to about 2000 nm, an optical transmittance of the light control film versus an incident angle of the incident light in a first incident plane has a peak transmittance of greater than about 2% with a corresponding first full width at half maximum (FWHM) of between about 5 degrees and about 120 degrees.

30 . A method of fabricating a light control film, comprising:
providing a plurality of first films, each first film having an orthogonal length and width and comprising a plurality of alternating optically transparent polymeric first regions and light absorbing polymeric second regions, the first and second regions extending along the length and arranged along the width, each first region having a thickness along a thickness direction substantially orthogonal to the length and width; forming a stack of the first films along the thickness direction; and applying at least one of pressure and heat to the stack of first films along at least one direction substantially orthogonal to the length resulting in an integral block comprising optically transparent columns formed from the first regions, wherein the columns are arranged to define a plurality of substantially parallel alternating substantially planar rows of the columns and substantially planar rows of continuous light absorbing polymeric material, wherein the at least one of pressure and heat modifies the thickness of the polymeric first regions, such that in at least one cross-section orthogonal to the thickness direction and for each pair of a plurality of adjacent columns, the adjacent columns are nested and separated by the light absorbing polymeric material.

31 . The method of claim 30 , wherein each the first films comprises at least one light absorbing layer substantially coextensive with the first film along the length and width.

Assignees

• 3M Innovative Properties Company

Inventors

• Fay William T
• Lindquist Timothy J
• Antila Garth V
• Johnson Stephen A
• Yu Li
• Pham Tri D

Classifications

• G02B2207/123

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

• G02B5/003 Primary

  Light absorbing elements · CPC title

• G02B5/223 Primary

  containing organic substances, e.g. dyes, inks or pigments · CPC title