The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 13, 1990
Filed:
Nov. 20, 1987
Randal W Tustison, Lexington, MA (US);
Dennis G Montanari, Townsend, MA (US);
Raytheon Company, Lexington, MA (US);
Abstract
An impact resistant antireflection coating for an optical element which mitigates damage to the optical element when an air flight system having the optical element is flown through a high velocity droplet impact medium is described. The coating comprises a material having a relatively high modulus of elasticity compared to the modulus of elasticity of the material of the optical element. The coating is deposited to a half wavelength thickness at a wavelength which must be maximally transmitted through the optical element. A quarter wavelength antireflection coating layer at the wavelength which must be maximally transmitted through the optical element is then disposed over the impact protection coating layer. The material of the antireflection coating is preferably of a high modulus of elasticity material having a refractive index which is intermediate the refractive index of the material of the base layer and the medium through which the airborne system is flown.