Abstract:
Thin film optical variable article to be used in a reflection mode having a gold to green color shift with angle for currency authentication and adapted to be carried by a substantially opaque currency sheet which serves as a substrate. The article includes a substantially transparent, optically thick element carrying a colorant and having first and second surfaces and a multilayer interference coating carried on one of said first and second surfaces. The article is adapted to be carried by the currency sheet so that the coating faces the currency sheet and the colorant carrying element serves as a superstrate facing the incident light. The multilayer interference coating is comprised of a substantially opaque layer of aluminum nearest the substrate, followed by a layer of magnesium fluoride, and then by a layer of chromium having substantial transmission. The colorant has a yellow hue whereby at normal incidence of light the article has a coppery-gold color shifting towards a vivid green at non-normal incidence of light. The colorant operates in an essentially subtractive mode to cause a modification of the normal incidence gold color and the color shift with angle properties as seen by reflection.
Abstract:
Thin film optical variable article to be used in a reflection mode having a gold to green color shift with angle for currency authentication and adapted to be carried by a substantially opaque currency sheet which serves as a substrate. The article includes a substantially transparent, optically thick element carrying a subtractive colorant and having first and second surfaces and a multilayer interference coating carried on one of said first and second surfaces. The article is adapted to be carried by the currency sheet so that the coating faces the currency sheet and the colorant carrying element serves as a superstrate facing the incident light. The multilayer interference coating is comprised of a substantially opaque layer of aluminum nearest the substrate, followed by a layer of magnesium fluoride, and then by a layer of chromium having substantial transmission. The colorant has a yellow hue. At normal incidence of light the article has a coppery-gold color shifting towards a vivid green at non-normal incidence of light. The colorant operates in an essentially subtractive mode in combination with the multilayer interference coating to provide the color shift from gold to green at two different angles of incidence and substantially no color at higher angles of incidence to cause a modification of the normal incidence gold color and the color shift with angle properties as seen by reflection.
Abstract:
Optical article having a substrate with first and second surfaces and with a conductive antireflection coating disposed on the first surface. The conductive antireflection coating is comprised of at least one layer of a low index material carried by said first surface and a thin transparent conducting layer of a material having a high index of refraction carried by the layer of material having a low index of refraction. The conducting layer provides an exposed surface to which the direct electrical contact can be made. The conducting layer has an optical thickness ranging from 1.0 to 30.0 nanometers. The layer of material having a low index of refraction has its design thickness reduced to compensate for the thickness of the conducting layer whereby the conducting layer does not seriously degrade the optical performance of the coating over that which could be obtained without the use of the conducting layer.
Abstract:
Thin film optically variable article having substantial color shift with varying angle of light incidence and viewing and including an optically thick, substantially transparent element carrying a colorant and having first and second surfaces. A multilayer interference coating is carried on one of said first and second surfaces. The colorant serves to modify in essentially a subtractive mode the color at normal incidence and the color shift with angle of the multilayer interference coating as seen by reflection or transmission.
Abstract:
Thin film optical variable article to be used in a reflection mode having a gold to green color shift with angle for currency authentication and adapted to be carried by a substantially opaque currency sheet which serves as a substrate. The article includes a substantially transparent, optically thick element carrying a subtractive colorant and having first and second surfaces and a multilayer interference coating carried on one of said first and second surfaces. The article is adapted to be carried by the currency sheet so that the coating faces the currency sheet and the colorant carrying element serves as a superstrate facing the incident light. The multilayer interference coating is comprised of a substantially opaque layer of aluminum nearest the substrate, followed by a layer of magnesium fluoride, and then by a layer of chromium having substantial transmission. The colorant has a yellow hue. At normal incidence of light the article has a coppery-gold color shifting towards a vivid green at non-normal incidence of light. The colorant operates in an essentially subtractive mode in combination with the multilayer interference coating to provide the color shift from gold to green at two different angles of incidence and substantially no color at higher angles of incidence to cause a modification of the normal incidence gold color and the color shift with angle properties as seen by reflection.
Abstract:
An energy control sheet, including a highly transparent substructure having first and second surfaces, a substantially transparent, thin film metal layer formed on one surface of the substructure, and a highly transparent thin film dielectric layer formed over said metal layer. The dielectric layer comprises a mixed metal oxide layer having metal constituents of at least one lanthanide series metal (e.g. cerium oxide) and at least one transition or semiconductor metal (e.g. tin oxide). The dielectric layer is characterized by substantial water vapor impermeability so that the weatherability of the energy control sheet is substantially improved. The metal layer is either a silver layer or a silver-palladium alloy.