LATENT IMAGES COMPRISING PHASE SHIFTED MICRO PRINTING

摘要

A security device comprising a substrate having applied thereto an array of characters, the characters being of a sufficiently small size as to appear uniform when ordinarily viewed but individually identifiable when viewed with the aid of appropriate magnification means, whereby group(s) of the characters are phase-shifted relative to the others in such a manner as to collectively define an image, the image being relatively indiscernible when the device is ordinarily viewed but discernible when viewed with the aid of a finding screen.