Patent ID: 8739954

Claim:
A validation apparatus comprising: at least one broadband source for illuminating an item of currency; at least three specified physical filters, wherein each of the at least three specified physical filters has a transmission spectrum similar to at least one approximating function for reconstructing a predetermined reference spectrum, the reference spectrum being similar to an emission spectrum of at least a portion of a document, wherein each of the at least three specified filters filter light emitted from each respective broadband source such that the resulting transmission spectrum is similar to the predetermined reference spectrum; at least one receiver for receiving filtered light emitted from the at least one broadband source; a transportation unit for transporting the item of currency within the validation apparatus; wherein the at least three specified physical filters are positioned between the at least one broadband source and the at least one receiver; and wherein the light received by the at least one receiver is at least one of light reflected by or light transmitted through the item of currency.