Patent ID: 6429927
Filing Date: 2002-08-06
Classification: G06K

Abstract:
An optical imaging device comprisinga light transmitting element having at least a first surface on which an imaged object can be placed and at which incident light beam transmitted through the light transmitting element may undergo frustrated total internal reflection, and a second surface through which light reflected from the first surface may exit as a reflected beam, an image sensor disposed at a distance from the light transmitting element for receiving an image of said object from said light transmitting element, a lens disposed in the path of said reflected beam between the light transmitting element and the sensor for focusing said reflected beam to produce a focused beam, the lens having two dissimilar surfaces, a first refractive convex surface facing the incident reflected beam from the light-transmitting element, and a second surface having a significantly lesser curvature than said first convex surface, and a reflective surface disposed adjacent said second surface for reflecting said reflected beam through said refractive surface, onto said image sensor so that an image of said object can be detected, wherein the incident reflected beam passes through said refractive surface immediately before reflection off of the reflective surface and the reflected beam passes through said refractive surface immediately after reflection off of the reflective surface.