Patent ID: 6163034
Filing Date: 2000-12-19
Classification: G07D

Abstract:
A validator comprising a pathway through which a banknote is moved past an optical sensor which evaluates optical characteristics on a face of a banknote; said optical sensor comprising a lens, a plurality of radiation emitters and a radiation receiver, said lens having a first surface which is generally planar and a second surface which is convex with said surfaces defining a focal point of said lens which faces said convex surface, said pathway including an opening therein which receives said lens with said planar surface closing said opening and forming part of said pathway, said radiation emitters and said radiation receiver being closely clustered at said focal point and including a shield member which isolates said receiver from direct radiation of said emitters, said lens collimating the emitted radiation of said emitters to produce parallel rays of radiation for radiating a banknote as it moves past said sensor and to focus reflected radiation from said banknote that impinges said lens on said receiver, said convex surface of said lens being selected to direct radiation reflected by said convex surface away from said receiver to reduce cross talk between said receiver and said emitters.