Color display system utilizing red and cyan light

Claim 1

IN A COLOR DISPLAY SYSTEM FOR PRODUCING COLORED IMAGES FROM FIRST AND SECOND RECORDS: A VIEWING SCREEN COMPRISING PARTICLES OF A FIRST PHOSPHOR WHICH EMIT LIGHT OF A FIRST COLOR WHEN EXCITED BY A BEAM OF ELECTRONS HAVING A VELOCITY OF AT LEAST A FIRST PREDETERMINED VALUE, AND PARTICLES OF A SECOND PHOSPHOR EACH HAVING A SURFACE LAYER WHICH CONSTITUTES A PARTIAL BARRIER TO ELECTRONS WHEREBY THE SECOND PHOSPHOR PARTICLES HAVE A HIGHER ELECTRON ENERGIZATION THESHOLD THAN THAT OF SAID FIRST PHOSPHOR PARTICLES, SAID SECOND PHOSPHOR PARTICLES EMITTING A SECOND COLOR LIGHT SUBSTANTIALLY COMPLEMENTARY TO A FIRST COLOR WHEN EXCITED BY A BEAM OF ELECTRONS HAVING A VELOCITY OF AT LEAST A SECOND PREDETERMINED VALUE WHICH IS GREATER THAN SAID FIRST VALUE, MEANS FOR GENERATING A FIRST BEAM OF ELECTRONS HAVING A VELOCITY OF SAID FIRST PREDETERMINED VALUE AND AN INTENSITY MODULATED IN ACCORDANCE WITH SAID FIRST RECORD THEREBY TO CAUSE SAID FIRST PHOSPHER PARTICLES TO EMIT LIGHT OF SAID FIRST COLOR AND PRODUCE AN IMAGE IN SAID FIRST COLOR CORRESPONDING TO SAID RECORD AND MEANS FOR GENERATING A SECOND BEAM OF ELECTRONS HAVING A VELOCITY OF SAID SECOND PREDETERMINED VALUE AND AN INTENSITY MODULATED IN ACCORDANCE WITH SAID SECOND RECORD THEREBY TO CAUSE BOTH SAID FIRST AND SECOND PHOSPHOR PARTICLES TO EMIT SUBSTANTIALLY ACHROMATIC LIGHT AND PRODUCE AN IMAGE IN SUBSTANTIALLY ACHROMATIC LIGHT CORRESPONDING TO SAID SECOND RECORD.