Patent ID: 7017812

Claim:
A symbol reader for reading marked regions on a substrate comprising: at least one light source providing an impingement beam; a beam splitter receiving the impingement beam from the at least one light source and splitting the impingement beam emitted from the at least one light source to allow some light from the impingement beam to contact the substrate as a contact beam while allowing some light to proceed in a first direction to not contact the substrate; a reflected beam proceeding one hundred and eighty degrees relative to the contact beam returned from the substrate, said reflected beam proceeding into the beam splitter where a first portion of the reflected beam is directed in a second direction 180 degrees relative to the first direction, and a second portion of the reflected beam passes through the beam splitter; a telecentric lens positioned relative to the beam splitter to receive one of the first and second portions of the reflected beam after passing through the beam splitter; a sensor located opposite of the telecentric lens from the beam splitter, said sensor receiving the portion of the reflected beam after it passes through the telecentric lens.