Voltage-indicating apparatus employing electroquenchable phosphor layer

Claim 1

A VOLTAGE INDICATOR COMPRISING: A PHOSPHOR LAYER IN WHICH LUMINESCENCE IS EXCITABLE BY IRRADIATION OF SAID LAYER WITH RADIANT ENERGY OF A GIVEN WAVELENGTH AND IS QUENCHABLE AT ANY REGION OF SAID LAYER, DURING SAID IRRADIATION, BY APPLICATION OF A REVERSE-BIASING POTENTIAL TO A RECTIFYING CONNECTION MADE TO SAID REGION, FIRST AND SECOND CONDUCTIVE LAYER RESPECTIVELY APPLIED TO OPPOSING SURFACES OF SAID PHOSPHOR LAYER, AT LEAST PORTIONS OF SAID TWO CONDUCTIVE LAYERS BEING OVERLAPPED, ONE OF SAID TWO CONDUCTIVE LAYERS HAVING A COMPOSITION SUCH TAHT SAID ONE LAYER MAKES A RECTIFYING CONNECTION TO THE AREA OF SAID PHOSPHOR LAYER COVERED BY SAID ONE LAYER, AND ONE OF SAID TWO CONDUCTIVE LAYERS BEING TRANSMISSIVE OF RADIANT ENERGY EMITTED BY SAID PHOSPHOR LAYER WHEN IRRADIATE WITH RADIANT ENERGY OF SAID GIVEN WAVELENGTH, MEANS FOR ESTABLISHING A POTENTIAL GRADIENT BETWEEN FIRST AND SECOND SPACED PORTIONS OF SAID FIRST CONDUCTIVE LAYER, SAID GRADIENT-ESTABLISHING MEANS COMPRISING FIRST MEANS FOR MAKING AN ELECTRICAL CONNECTION TO SAID FIRST PORTION, SAECOND MEANS FOR MAKING AN ELECTRICAL CONNECTION TO SAID SECOND PORTION, AND MEANS FOR APPLYING A UNIDIRECTIONAL VOLTAGE BETWEEN SAID FIRST MEANS AND SAID SECOND MEANS, MEANS FOR APPLYING RADIANT ENERGY OF SAID GIVEN WAVELENGTH TO SAID PHOSPHOR LAYER TO EXCITE SAID PHOSPHOR LAYER INTO LUMINESCENCE, AND MEANS FOR APPLYING BETWEEN SAID SECOND CONDUCTIVE LAYER AND ONE OF SAID FIRST AND SECOND MEANS A UNIDIRECTIONAL VOLTAGE TO BE MEASURED, WHEREBY, WHEN THE POTENTIAL OF SAID SECOND CONDUCTIVE LAYER IS ESTABLISHED BY SAID VOLTAGE TO BE MEASURED AT A VALUE INTERMEDIATE THE RESPECTIVE POTENTIALS OF SAID FIRST MEANS AND SAID SECOND MEANS, A PART OF SAID RECTIFYING CONNECTION IS REVERSE-BIASED TO QUENCH THE LUMINESCENCE OF THE REGION OF SAID PHOSPHOR LAYER COVERED BY SAID REVERSE-BIASED PART.