Multi-cathode display tube

Claim 1

A MULTI-CATHODE STRUCTURE FOR USE IN A MULTI-CATHODE CHARACTER DISPLAY TUBE, COMPRISING: A PLURALITY OF COLD CATHODES EACH IN THE FORM OF A PREDETERMINED CHARACTER, A FRAME OF THE SAME METAL AS SAID CHARACTER AND SURROUNDING A RESPECTIVE CATHODE, EACH FRAME BEING CONNECTED TO A CORRESPONDING CHARACTER IN AT LEAST TWO POINTS, AND EACH FRAME AND CHARACTER ASSEMBLY BEING CONSTITUTED BY AN INTEGRALLY FORMED PIECE, EACH FRAME BEING PROVIDED WITH A PAIR OF HOLES FOR PASSING THERETHROUGH SUPPORTING MEANS; AND SUPPORTING MEANS INCLUDING A PAIR OF INSULATING RODS EXTENDING THROUGH SAID HOLES, THE CATHODE AND FRAME ASSEMBLIES BEING STACKED IN SUCH A MANNER THAT SAID RODS PASS THROUGH THE PAIR OF HOLES IN EACH OF SAID FRAMES, AND INSULATING WASHERS, SUCCESSIVE CATHODES BEING EACH LOCATED SANDWICH-WISE BETWEEN TWO INSULATING WASHERS, EACH INSULATING WAHSER BEING SUBSTANTIALLY OF THE SAME SHAPE AS SAID FRAMES WHEREBY SAID FRAMES ARE MASKED AND THE ILLUMINATION THEREOF IS PRECLUDED DURING OPERATION OF THE TUBE, AT LEAST SOME OF SAID INSULATING WASHERS BEING PROVIDED WITHIN THE VICINITY OF A PREDETERMINED CHARACTER WITH TONGUE PORTIONS FOR MASKING PREDETERMINED PORTIONS OF THE CORRESPONDING CHARACTER THEREBY PRECLUDING ILLUMINATION OF SAID PORTIONS DURING OPERATION OF THE TUBE.