US Patent 7760971 Anti-EMI lens module

An anti-EMI lens module used in a bill acceptor is disclosed to include a circuit board, which has a plurality of electric recognition devices and a grounding device surrounding the electric recognition devices, a holder base mounted on the circuit board and holding a lens device and having a plurality of through holes respectively aimed at the electric recognition devices and a metal conducting layer disposed in contact with the grounding device of the circuit board and forming with the grounding device a grounding loop for absorbing and discharging static electricity during operation of the bill acceptor to protect the electric recognition devices against static electricity, radiowave and electromagnetic interference.