US 20050260419A1
(19) United States
(12) Patent Application Publication (io) Pub. No.: US 2005/0260419 Al
Hukari et al. (43) Pub. Date: Nov. 24,2005
(54) PROTECTIVE LAYERS FOR OPTICAL COATINGS
(75) Inventors: Kyle W. Hukari, Davis, CA (US);
Peter A. Maschwitz, Sebastopol, CA
(US); Rand D. Dannenberg, Benicia,
CA (US)
Correspondence Address:
OBLON, SPIVAK, MCCLELLAND, MAIER &
NEUSTADT, PC.
1940 DUKE STREET
ALEXANDRIA, VA 22314 (US)
(73) Assignee: AFG INDUSTRIES, INC., Kingsport, TN
(21) Appl. No.: 10/809,700
(22) Filed: Mar. 26, 2004
Related U.S. Application Data
(62) Division of application No. 10/054,973, filed on Jan. 25, 2002, now Pat. No. 6,770,321.
Publication Classification
(51) Int. CI.7 B32B 17/06
(52) U.S. CI 428/428; 428/432; 428/408
(57) ABSTRACT
An optical coating on a transparent substrate is provided with a temporary layer of carbon as protection during manufacturing against scratches and corrosive environments. When the optical coating and/or substrate are tempered in an atmosphere reactive to carbon, such as air, the layer of carbon is removed as a carbon-containing gas. For an optical coating with a brittle, glassy, outermost layer furthest from the substrate, additional protection is provided by a scratch propagation blocker layer between the outermost layer and the carbon protective layer.
carbon protective coating 3
scratch propagation blocker layer 4
Si3N4 layer 2a
optical coating 2
