Anti-reflection coatings and coated articles

• US 6,172,812 B1
• Filed: 07/30/1999
• Issued: 01/09/2001
• Est. Priority Date: 01/27/1997
• Status: Expired due to Term

• Current Assignee: Peter (I) D. Haaland
• Original Assignee: Mckoy B. Vincent, Peter (I) D. Haaland
• Inventors: Haaland, Peter D., McKoy, B. Vincent
• Primary Examiner(s): Nguyen, Thong
• Assistant Examiner(s): CHERRY, EUNCHA P
• Application Number:
  US09/364,748
• Time in Patent Office: 529 Days
• Field of Search: 359/589, 359/580, 359/581, 359/582, 359/586, 359/588, 359/590, 428/421, 428/422, 427/164, 427/165
• US Class Current: 359/589
• CPC Class Codes: C03C 17/225 Nitrides
• CPC Class Codes: C03C 17/256 Coating containing TiO2
• CPC Class Codes: C03C 17/30 with silicon-containing compounds
• CPC Class Codes: C03C 17/32 with synthetic or natural resins C03C17/30 takes precedence
• CPC Class Codes: C03C 17/328 Polyolefins
• CPC Class Codes: C03C 17/34 with at least two coatings having different compositions C03C17/44 takes precedence
• CPC Class Codes: C03C 17/42 at least one coating of an organic material and at least one non-metal coating
• CPC Class Codes: C03C 2217/734 comprising an alternation of high and low refractive indexes
• CPC Class Codes: C23C 16/52 Controlling or regulating the coating process C23C16/45557, C23C16/279 take precedence
• CPC Class Codes: G02B 1/11 Anti-reflection coatings
• CPC Class Codes: G02B 1/111 using layers comprising organic materials

Abstract

Coated optical substrates and a method of coating optical substrates with anti-reflective (AR) coatings are described. The composition of the coating is determined by material constraints such as adhesion, durability, ease of manufacture, and cost. The thickness of one or more layers of AR material is determined by minimizing the product of the Fresnel reflection coefficients for the coated article with the angle- and wavelength-dependent sensitivity of the human visual system. Preferred designs have a value of perceived reflectance, F, less than or equal to 1.25 F_min where F_min is the minimized perceived reflectance for the coated article. Coatings which have minimal perceived reflection while maintaining reflections with desired visually perceived colors are also described.

Claims

1. A transparent or translucent coated article having a perceived reflectance F, wherein F=∫

∫

S(λ

,θ

)R(λ

,θ

)dλ

dθ

where

λ

is wavelength,

θ

is incident angle,

S(λ

,θ

) is human sensitivity function as a function of the wavelength and the incident angle, and

R(λ

,θ

) is an average of p- and s-polarized reflectances, the coated article comprising;

an optical substrate; and

one or more layers of anti-reflection material coated on at least a portion of the optical substrate, said one or more layers of anti-reflection material having a thickness such that the perceived reflectance of the coated article is less than or equal to 1.25F_min, where F_min is a minimized perceived reflectance of the coated article.

2. An article as recited in claim 1, wherein the optical substrate is an ophthalmic lens.

3. An article as recited in claim 2, wherein the ophthalmic lens is coated with the anti-reflection material on at least a portion of one or both lens surfaces and/or its edge.

4. An article as recited in claim 1, wherein the optical substrate is a window.

5. An article as recited in claim 1, wherein the optical substrate is a television screen or computer monitor.

6. A coated article as recited in claim 1, wherein at least one layer of anti-reflection material comprises a fluorocarbon film.

7. An article as recited in claim 6, wherein the fluorocarbon film is a plasma deposition product of a perfluorinated organic compound.

8. An article as recited in claim 7, wherein the perfluorinated organic compound is a perfluoroaliphatic or perfluorocycloaliphatic compound.

9. An article as recited in claim 8, wherein the perfluorinated organic compound is selected from the group consisting of perfluorocyclobutane, hexafluoroethane, tetrafluoroethylene, perfluoropropene, and mixtures thereof.

10. An article as recited in claim 6, wherein the fluorocarbon film comprises polytetrafluoroethylene.

11. A coated article as recited in claim 1, wherein at least one layer of anti-reflection material comprises an organic or organosilicon film.

12. A coated article as recited in claim 1, wherein at least one of layer of anti-reflection material comprises a plasma-enhanced chemical vapor deposition product of one or more precursors selected from the group consisting of Si(CH₃)₄, HSi(CH₃)₃, thiophene, furan, benzene, Ti(OC₂H₅)₄, Ti(OC₃H₇)₄, Ti(N(C₂H₅)₂)₄, and perfluorinated organic compounds.

13. An article as recited in claim 1, wherein each layer of anti-reflection material has a physical thickness greater than about 5 nm and less than about 1 micron.

14. An article as recited in claim 1, further comprising an optically thin metal layer deposited on the optical substrate and/or on a layer of anti-reflection material.

15. An article as recited in claim 1, further comprising a layer of hydrophobic material.

16. An article as recited in claim 1, having a color, when viewed at a specified angle or angles, under a specified illumination, that is perceived to lie within a specified volume element of color space defined by the color'"'"'s CIE chromaticity coordinates.

17. An article as recited in claim 16, where the illumination is selected from normal or spectrally filtered daylight, tungsten lamps, fluorescent lamps, and arc lamps.

18. An article as recited in claim 16, where the volume element is defined by a circle of radius 0.1 centered at (1/3, 1/3) in 1931.

19. An article as recited in claim 16, where the volume element is selected to match a background color and thereby decrease the visibility of reflected light.

20. A method for making a transparent or translucent coated article in which an optical substrate is coated with one or more layers of anti-reflection material, said coated article having a perceived reflectance F, wherein F=∫

∫

S(λ

,θ

)R(λ

,θ

)dλ

dθ

where

λ

is wavelength,

θ

is incident angle,

S(λ

,θ

) is human sensitivity function as a function of the wavelength and the incident angle, and

R(λ

,θ

) is an average of p- and s-polarized reflectances, the method comprising;

initiating deposition of one or more layers of anti-reflection material on the substrate; and

terminating deposition when said one or more layers reach a desired thickness such that the perceived reflectance of the coated article is less than or equal to 1.25F_min, where F_min is a minimum perceived reflectance of the coated article.

21. The method of claim 20, wherein the layer is deposited by plasma-enhanced chemical vapor deposition.