Patent ID: 7654581
Filing Date: 2010-02-02
Classification: B42D,Y10S

Abstract:
1. A security document having a security feature and a first side and a second side, wherein said security feature comprises: (a) a transparent window extending through said security document from said first side to said second side; (b) a transparent ultraviolet light blocking layer within the area defined by said transparent window; and, (c) a printed first ultraviolet fluorescent ink pattern between said transparent ultraviolet light blocking layer and said first side, and within said transparent window, said first ultraviolet fluorescent ink pattern normally being invisible but becoming visible when illuminated with ultraviolet light; wherein when illuminated with ultraviolet light from said first side, said first ultraviolet fluorescent ink pattern becomes visible in said transparent window when viewed from said first side but is not visible in said transparent window when viewed from said second side.