Photosensitive radiant-energy transducers

Claim 1

A RADIANT-ENERGY TRANSDUCER COMPRISING: A FIRST ELECTRODE; A PHOTOCONDUCTIVE ELEMENT IN REGISTRATION WITH SAID ELECTRODE AND HAVING AN ELECTRICAL IMPEDANCE PER UNIT AREA WHICH IS VARIABLE IN RESPONSE TO INCIDENT RADIATIONS; AN ELECTROLUMINESCENT ELEMENT, RESPONSIVE TO AN APPLIED ELECTRICAL POTENTIAL EXCEEDING A PREDETERMINED THRESHOLD MAGNITUDE FOR EMITTING LIGHT RADIATIONS, IN REGISTRATION WITH SAID PHOTOCONDUCTIVE ELEMENT; A SECOND ELECTRODE IN JUXTAPOSITION WITH SAID ELECTROLUMINESCENT ELEMENT OPPOSITE SAID PHOTOCONDUCTIVE ELEMENT; SAID FIRST ELECTRODE BEING AT LEAST SUBSTANTIALLY TRANSPARENT TO SAID INCIDENT RADIATIONS AND SAID SECOND ELECTRODE BEING AT LEAST SUBSTANTIALLY TRANSPARENT TO SAID LIGHT RADIATIONS; MEANS FOR PROJECTING INCIDENT RADIATIONS THROUGH SAID FIRST ELECTRODE UPON SAID PHOTOCONDUCTIVE ELEMENT TO CAUSE VARIATIONS IN ITS ELECTRICAL IMPEDANCE PER UNIT AREA; AND MEANS, INCLUDING A SOURCE OF UNIDIRECTIONAL POTENTIAL SUPERIMPOSED UPON AN ALTERNATING POTENTIAL WITH SAID UNIDIRECTIONAL AND ALTERNATING POTENTIALS INDIVIDUALLY OF LESS MAGNITUDE THAN SAID THRESHOLD POTENTIAL MAGNITUDE BUT TOGETHER HAVING A MAGNITUDE EXCEEDING SAID THRESHOLD POTENTIAL MAGNITUDE, FOR ESTABLISHING AN ELECTRICAL POTENTIAL DIFFERENCE BETWEEN SAID ELECTRODES TO CAUSE SAID ELECTROLUMINESCENT ELEMENT TO EMIT LIGHT IN RESPONSE TO THE VARIATIONS IN THE VOLTAGE APPLIED TO SAID ELECTROLUMINESCENT ELEMENT RESULTING FROM SAID VARIATIONS IN SAID ELECTRICAL IMPEDANCE OF SAID PHOTOCONDUCTIVE ELEMENT.