System to process a valuable document

A sensing system to process at least one valuable document, the system comprising: a light source to generate a light beam; at least one light pipe coupled to the light source, wherein the light pipe has one or more diverting surfaces to direct the light beam at a predetermined angle of incidence onto the valuable document; at least one reflective surface to receive a first portion of the light beam transmitted through the valuable document and to reflect the first portion of the light beam towards the valuable document; a light detector to receive at least a second portion of the light beam re transmitted through the valuable document; and one or more diverting surfaces to direct at least the second portion of the light beam to the light detector. IN N1 oo h C4 o 00 N% N% loe Co6