Omnidirectional high chroma red structural colors

Patent metadata

Field	Value
Publication number	US-2016245969-A1
Application number	US-201615144283-A
Country	US
Kind code	A1
Filing date	May 2, 2016
Priority date	Jan 28, 2015
Publication date	Aug 25, 2016
Grant date	—

Abstract

A multilayer thin film that reflects an omnidirectional high chroma red structural color. The multilayer thin film may include a reflector layer, at least one absorber layer extending across the reflector layer, and an outer dielectric layer extending across the at least one absorber layer. The multilayer thin film reflects a single narrow band of visible light when exposed to white light and the outer dielectric layer has a thickness of less than or equal to 2.0 quarter wave (QW) of a center wavelength of the single narrow band of visible light.

First claim

What is claimed is:

1 . A multilayer interference thin film that reflects an omnidirectional high chroma red structural color comprising:
a multilayer thin film having a reflector layer, at least one absorber layer extending across the reflector layer; and an outer dielectric layer extending across the at least one absorber layer; wherein the multilayer thin film reflects a single narrow band of visible light when exposed to white light and the outer dielectric layer has a thickness of less than or equal to 2.0 QW of a center wavelength of the single narrow band of visible light, the single narrow band of visible light having:
a visible FWHM width of less than 200 nm;
a color between 0° and 30° on a Lab color space; and
a hue shift of less than 30° on the Lab color space when the multilayer thin film is viewed at angles between 0-45° relative to a direction normal to an outer surface of the outer dielectric layer.

2 . The multilayer interference thin film of claim 1 , wherein the reflector layer has a thickness between 5-200 nm and is made from at least one of Al, Ag, Pt and Sn.

3 . The multilayer interference thin film of claim 1 , wherein the at least one absorber layer is at least one dielectric absorber layer extending between the reflector layer and the outer dielectric layer.

4 . The multilayer interference thin film of claim 3 , wherein the at least one dielectric absorber layer is made from at least one of an oxide and a nitride.

5 . The multilayer interference thin film of claim 4 , wherein the at least one dielectric absorber layer is made from at least one of Fe 2 O 3 and TiN, and has a thickness between 5-500 nm.

6 . The multilayer interference thin film of claim 1 , wherein the outer dielectric layer has an index of refraction greater than 1.6.

7 . The multilayer interference thin film of claim 6 , wherein the outer dielectric layer is made from at least one of MgF 2, ZnS and TiO 2 .

8 . The multilayer interference thin film of claim 7 , wherein the center wavelength of the single narrow band of reflected visible light is between 600-700 nm and the thickness of the outer dielectric layer is less than 175 nm.

9 . The multilayer interference thin film of claim 1 , wherein the at least one absorber layer is a dielectric absorber layer and a transparent absorber layer.

10 . The multilayer thin film of claim 9 , wherein the transparent absorber layer extends across the dielectric absorber layer and is located between the dielectric absorber layer and the outer dielectric layer.

11 . The multilayer interference thin film of claim 9 , wherein the dielectric absorber layer is made from at least one of Fe 2 O 3 and TiN.

12 . The multilayer interference thin film of claim 10 , wherein the dielectric absorber layer has a thickness between 5-500 nm

13 . The multilayer interference thin film of claim 9 , wherein the transparent absorber layer is made from at least one of Cr, Ge, Ni, stainless steel, Ti, Si, V, TiN, W, Mo, Nb and Fe 2 O 3 .

14 . The multilayer interference thin film of claim 13 , where the transparent absorber layer has a thickness between 5-20 nm

15 . The multilayer interference thin film of claim 1 , wherein the single narrow band of visible light has a visible FWHM width of less than 200 nm, a color between 5° and 25° on the Lab color space, and a hue shift of less than 20° on the Lab space color map when the multilayer thin film is viewed at angles between 0-45° relative to a direction normal to an outer surface of the outer dielectric layer.

16 . The multilayer interference thin film of claim 1 , wherein the single narrow band of visible light has a visible FWHM width of less than 200 nm, a color between 10° and 25° on the Lab color space, and a hue shift of less than 15° on the Lab space color map when the multilayer thin film is viewed at angles between 0-45° relative to a direction normal to an outer surface of the outer dielectric layer.

17 . An omnidirectional high chroma red structural color multilayer thin film comprising:
a multilayer thin film having a reflector layer, a dielectric absorber layer extending across the reflector layer, an outer dielectric layer extending across the dielectric absorber layer and a transparent absorber layer extending between the dielectric absorber layer and the outer dielectric layer; wherein the multilayer thin film reflects a single narrow band of visible light when exposed to white light and the outer dielectric layer has a thickness of less than or equal to 2.0 QW of a center wavelength of the single narrow band of visible light, the single narrow band of visible light having:
a visible FWHM width of less than 200 nm;
a color between 0° and 30° on a Lab color space; and
a hue shift of less than 30° on the Lab color space when the multilayer thin film is viewed at angles between 0-45° relative to a direction normal to an outer surface of the outer dielectric layer.

18 . The omnidirectional high chroma red structural color multilayer thin film of claim 17 , wherein the dielectric absorber layer is made from at least one of an oxide and a nitride, and has a thickness between 5-500 nm

19 . The omnidirectional high chroma red structural color multilayer thin film of claim 18 , wherein the dielectric absorber layer is made from at least one of Fe 2 O 3 and TiN.

20 . The omnidirectional high chroma red structural color multilayer thin film of claim 17 , wherein the transparent absorber layer is made from at least one of Cr, Ge, Ni, stainless steel, Ti, Si, V, TiN, W, Mo, Nb and Fe 2 O 3, and has a thickness between 5-20 nm

Assignees

• Toyota Motor Eng & Mfg North America Inc

Inventors

• Banerjee Debasish
• Zhou Li Qin

Classifications

• G02B5/0858

  the reflecting layers comprising a single metallic layer with one or more dielectric layers · CPC title

• G02B5/26

  Reflecting filters (G02B5/28 takes precedence) · CPC title

• G02B5/0825

  the reflecting layers comprising dielectric materials only · CPC title

• G02B5/286 Primary

  having four or fewer layers, e.g. for achieving a colour effect · CPC title