Security document verification system with pressure-rupturable microcapsules
AssigneeWallace Computer Services, Inc.
InventorJohn C. H. Chang
Life of this patent
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Abstract
A pressure-sensitive, laser printer heat-resistant verification system for preventing unauthorized photoduplication of security documents comprising a support bearing an information area comprising a visible principal image, and a verification area comprising a localized, autogenous coating of a pressure-sensitive chromogenic composition for producing a visible colored image by external pressure. The chromogenic composition comprises (a) pressure-rupturable microcapsules containing a chromogen and (b) a color developer capable of reacting with the chromogen to form a visible image. The pressure-rupturable microcapsules and color developer are substantially coextensive on the support, and the verification area is spaced apart from the information area.
Claims29
A security document comprising:
- a support bearing an information area and a verification area;
- said information area comprising a visible principal image;
- said verification area comprising a localized, autogenous coating of a pressure-sensitive chromogenic composition for producing a visible colored image by external pressure, said chromogenic composition comprising (a) chromogen-containing pressure-rupturable microcapsules and (b) a color developer capable of reacting with said chromogen to form a visible image, said pressure-rupturable microcapsules and said color developer being substantially coextensive;
- all portions of said visible principal image on the same side of said support as said localized autogenous coating being spaced apart from all portions of said localized autogenous coating;
- whereby authenticity of said document can be readily confirmed by the appearance of said visible image when external pressure is applied to said localized, autogenous coating and unauthorized photoduplicates of said document are detected by the absence of said visible image.
A security document comprising:
- a support bearing an information area and a verification area;
- said information area comprising a visible principal image;
- said verification area comprising a localized, autogenous coating of a pressure-sensitive chromogenic composition for producing a visible colored image by external pressure, said chromogenic composition comprising (a) pressure-rupturable microcapsules containing a chromogen and an ultraviolet light absorbing compound;
- and (b) a color developer capable of reacting with said chromogen to form a visible image, said pressure-rupturable microcapsules and said color developer being substantially coextensive;
- said verification area being spaced apart from said information area;
- whereby authenticity of said document can be readily confirmed by the appearance of said visible image when external pressure is applied to said localized, autogenous coating and unauthorized photoduplicates of said document are detected by the absence of said visible image.
A security document comprising:
- a support bearing an information area and a verification area;
- said information area comprising a visible principal image;
- said verification area comprising a localized, autogenous coating of a pressure-sensitive chromogenic composition for producing a visible colored image by external pressure, said chromogenic composition comprising (a) pressure-rupturable microcapsules containing a chromogen and a hindered phenol to stabilize said chromogen;
- and (b) a color developer capable of reacting with said chromogen to form a visible image, said pressure-rupturable microcapsules and said color developer being substantially coextensive;
- and
- said verification area being spaced apart from said information area.
A security document comprising:
- a support bearing an information area and a verification area;
- said information area comprising a visible principal image;
- said verification area comprising a localized, autogenous coating of a pressure-sensitive chromogenic composition for producing a visible colored image by external pressure, said chromogenic composition comprising (a) chromogen-containing pressure-rupturable microcapsules;
- and (b) a color developer capable of reacting with said chromogen to form a visible image, said pressure-rupturable microcapsules and said color developer being substantially coextensive;
- said verification area being spaced apart from said information area;
- and
- said chromogenic composition being in the form of a latent image message, and said support has been treated with a coating of an inorganic pigment in a binder after application of said latent image message to conceal location of the latent image message.
Dependencies are inferred from the claim text.