Use of polarizing materials to overcome light leakage

Claim 1

AN OPTICAL RECORD-SENSING DEVICE COMPRISING: (A) A RADIATION SOURCE, THE RADIATION FROM SAID SOURCE BEING DIRECTED ALONG A PATH; (B) A RECORD MEMBER HAVING PERFORATED AND NON-PERFORATED AREAS AT A SELECTED LOCATION WHEREIN SAID NONPERFORATED AREAS ARE PARTIALLY TRANSPARENT, SAID PATH OF RADIATION FROM SAID SOURCE BEING DIRECTED AT SAID SELECTED LOCATION OF SAID RECORD MEMBER; (C) A FIRST PLANE POLARIZING MEANS INTERPOSED BETWEEN SAID RADIATION SOURCE AND SAID PARTIALLY TRANSPARENT RECORD MEMBER, SAID FIRST PLANE POLARIZING MEANS BEING ORIENTED ADJACENT SAID RADIATION SOURCE TO RECEIVE ENERGY RADIATION FROM SAID SOURCE, SAID FIRST PLANE POLARIZING MEANS BEING FURTHER ORIENTED ADJACENT SAID RECORD MEMBER; (D) A SENSING MEANS TO DETECT THE INTENSITY OF RADIATION ALONG SAID PATH; (E) A SECOND PLASNE POLARIZING MEANS INTERPOSED BETWEEN SAID RECORD MEMBER AND SAID SENSING MEANS, SAID SECOND PLANE POLARIZING MEANS BEING ORIENTED ACROSS SAID PATH OF RADIATION, THE AXES OF POLARIZATION OF SAID FIRST AND SECOND PLANE POLARIZING MEANS BEING SO ARRANGED THAT THE PROPORTION OF THE RADIATION TRANSMITTED TO SAID SENSING MEANS FROM SAID SECOND PLANE POLARIZING MEANS DEPENDS UPON WHETHER SUCH PLANE POLARIZED RADIATION HAS BEEN DEPOLARIZED BY TRANSMISSION THROUGH SAID PARTIALLY TRANSPARENT, NON-PERFORATED AREA AT SAID SELECTED LOCATION OF SAID RECORD MEMBER, OR HAS RETAINED ITS PLANE POLARIZATION ON PASSING THROUGH SAID PERFORATION FORMED IN SAID RECORD MEMBER AT SAID SELECTED LOCATION.