Antireflection coatings

• US 10,591,724 B2
• Filed: 10/20/2017
• Issued: 03/17/2020
• Est. Priority Date: 10/21/2016
• Status: Active Grant

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Neuman, George A., Saenger Nayver, Mario F., Anderson, John S.
• Primary Examiner(s): Crockett, Ryan
• Application Number:
  US15/788,939
• Publication Number:
  US 20180113306A1
• Time in Patent Office: 879 Days
• Field of Search: None
• CPC Class Codes: G02B 1/11 Anti-reflection coatings
• CPC Class Codes: G02B 1/113 using inorganic layer materials only
• CPC Class Codes: G02B 2027/0112 comprising device for genereting colour display
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 27/01 Head-up displays
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G02F 1/133502 Antiglare, refractive index matching layers
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/157 Structural association of cells with optical devices, e.g. reflectors or illuminating devices

Abstract

A transparency includes a first substrate having a first surface and a second surface. A second substrate includes a third surface and a fourth surface. An optical coating is positioned on the fourth surface. The optical coating having a refractive index of greater than about 1.8 and an nk ratio of greater than about 0.6. The reflectance of the fourth surface has a reflectance of less than about 1.2% as measured from the first surface.

Claims

1. An electro-optic element, comprising:

a first substrate defining a first surface and a second surface;

a second substrate defining a third surface and a fourth surface, wherein the second and third surfaces are positioned in a spaced apart configuration;

an electrochromic medium positioned between the first and second substrates;

an anti-reflective electrode positioned on the second surface comprising a first color suppression layer positioned proximate the second surface and a transparent conductive oxide between the color suppression layer and the third surface; and

a metal layer positioned on the anti-reflective electrode and positioned between the transparent conductive oxide and the electrochromic medium, wherein a reflectance as viewed through the first substrate is about 1% or less.

2. The electro-optic element of claim 1, further comprising:

a liquid crystal material positioned between the first and second substrates.

3. The electro-optic element of claim 1, wherein a sheet resistance of the transparent conductive oxide is about 12 ohms/sq or less.

4. The electro-optic element of claim 3, wherein a sheet resistance of the transparent conductive oxide is about 6 ohms/sq or less.

5. The electro-optic element of claim 1, wherein a reflectance as viewed through the first substrate is about 0.5% or less.

6. The electro-optic element of claim 1, wherein the reflectance is selected from at least one of an eye-weighted reflectance and an average reflectance over the visible light spectrum.

7. The electro-optic element of claim 1, wherein the metal layer comprises at least one of AlSi alloys, AlTi alloys, chromium, molybdenum, MoRe alloys, MoSi₂, niobium, cobalt, iridium, platinum, rhenium, ruthenium, stainless steel, tantalum, tungsten, vanadium, zirconium, mixtures thereof, and alloys thereof.

8. The electro-optic element of claim 1, wherein the metal layer comprises a thickness of from about 0.1 nm to about 5 nm.

9. The electro-optic element of claim 1, wherein the metal layer comprises a reflected color C* value in the CIELAB color system of less than about 10.

10. The electro-optic element of claim 1, wherein the color suppression layer comprises a graded refractive index.

11. The electro-optic element of claim 1, wherein the color suppression layer comprises a refractive index of from between about 1.6 to about 1.75.

12. The electro-optic element of claim 1, wherein the color suppression layer comprises a bi-layer including high refractive index material and low refractive index material.

13. The electro-optic element of claim 1, wherein the color suppression layer comprises a quarter-wave optical thickness for a wavelength between about 450 nm to about 600 nm.

14. The electro-optic element of claim 1, wherein the transparent conductive oxide comprises indium tin oxide (ITO).

15. The electro-optic element of claim 1, wherein the metal layer has a thickness such that a reflectance as viewed through the first substrate including the metal layer is within 10% of a reflectance as viewed through the first substrate in the absence of the metal layer and a transmission through the first substrate including the metal layer is decreased by greater than about 5% compared to a transmission through the first substrate in the absence of the metal layer.

16. The electro-optic element of claim 1, further comprising a transflective coating positioned proximate the first surface.

17. The electro-optic element of claim 1, wherein the metal layer comprises a refractive index real component n of greater than about 2.5, as measured at 550 nm.

18. The electro-optic element of claim 1, wherein the metal layer comprises a ratio nk of the real component n of the refractive index to the imaginary component k of the refractive index of between about 0.6 and about 2.0.

19. The electro-optic element of claim 1, further comprising one of a dielectric layer, an insulator layer, and a transparent conducting oxide layer positioned on the metal layer.

20. The electro-optic element of claim 1, wherein a transmittance as viewed through the first substrate is about 70% or greater.