Acute angle source of plural beams for color cathode ray tube

Claim 1

A CATHODE RAY TUBE COMPRISING A SCREEN HAVING ARRAYS OF DIFFERENT COLOR PHOSPHORS; BEAMS PRODUCING MEANS ANGULARLY DISPOSED WITH RESPECT TO EACH OTHER FOR PRODUCING A PLURALITY OF ELECTRON BEAMS WHICH ARE IN A COMMON PLANE AND ORIGINATE IN SPACED RELATION TO EACH OTHER AND AT ACUTE ANGLES TO EACH OTHER AND WHICH ARE DIRECTED TOWARD SAID SCREEN IN DIRECTIONS AT ANGLES TO EACH OTHER SO AS TO IMPINGE ON THE SCREEN AFTER INTERSECTING EACH OTHER AT A LOCATION IN THE TUBE BETWEEN SAID BEAM PRODUCING MEANS AND SAID SCREEN, SAID BEAM PRODUCING MEANS INCLUDING CATHODE MEANS HAVING ELECTRON-EMITTING SURFACES FACING GENERALLY IN SAID DIRECTIONS OF THE BEAMS, FIRST GRID MEANS CONFRONTING SAID ELECTRON-EMITTING SURFACES IN ADJACENT, SUBSTANTIALLY PARALLEL RELATION TO THE LATTER AND HAVING RESPECTIVE SPACED APART APERTURES FOR THE PASSAGE OF SAID ELECTRON BEAMS THERETHROUGH, AND A SECOND GRID HAVING A WALL CONFRONTING SAID FIRST GRID MEANS AT THE SIDE OF THE LATTER FACING AWAY FROM SAID CATHODE MEANS WITH PORTIONS OF SAID WALL BEING IN ADJACENT, SUBSTANTIALLY PARALLEL RELATION TO SAID FIRST GRID MEANS AND HAVING RESPECTIVE SPACED APART APERTURES WHICH ARE ALIGNED WITH RESPECTIVE APERTURES OF SAID FIRST GRID MEANS IN SAID DIRECTIONS OF THE RESPECTIVE BEAMS FOR PASSAGE OF THE LATTER THROUGH SAID APERTURES OF THE SECOND GRID; FIRST, SECOND AND THIRD TUBULAR ELECTRODES ARRANGED SUCCESSIVELY IN AXIAL ALIGNMENT BETWEEN SAID SECOND GRID AND SAID SCREEN FOR THE PASSAGE OF ALL OF SAID BEAMS THERETHROUGH, SAID FIRST AND THIRD ELECTRODES BEING MAINTAINED AT A HIGH ELECTRICAL POTENTIAL RELATIVE TO SAID SECOND ELECTRODE FOR ESTABLISHING AN ELECTRICAL FIELD CONSTITUTING A MAIN FOCUSING ELECTRON LENS COMMON TO ALL OF SAID BEAMS AND BEING POSITIONED TO DISPOSE THE CENTER OF SAID ELECTRICAL FIELD SUBTANTIALLY AT SAID LOCATION WHERE THE BEAMS INTERSECT FOR DIMINISHING THE EFFECTS OF CERTAIN OPTICAL ABBERATIONS; AN AN END WALL ON SAID FIRST TUBULAR ELECTRODE AT THE END OF THE LATTER FACING TOWARD SAID WALL OF THE SECOND GRID WITH PORTIONS OF SAID END WALL BEING IN SUBSTANTIALLY PARALLEL RELATION TO SAID PORTIONS OF THE SECOND GRID WALL AND HAVING RESPECTIVE SPACED APART APERTURES WHICH ARE ALIGNED WITH SAID APERTURES OF THE SECOND GRID WALL IN SAID DIRECTIONS OF THE RESPECTIVE BEAMS FOR PASSAGE OF THE LATTER THROUGH SAID APERTURES IN THE END WALL OF SAID FIRST TUBULAR ELECTRODE, SAID SECOND GRID BEING MAINTAINED AT AN ELECTRICAL POTENTIAL SUBSTANTIALLY LESS THAN THAT OF SAID FIRST TUBULAR ELECTRODE FOR ESTABLISHING INDIVIDUAL ELECTRICAL FIELDS BETWEEN THE ALIGNED APERTURES OF SAID SECOND GRID WALL AND SAID END WALL OF THE FIRST TUBULAR ELECTRODE THROUGH WHICH THE RESPECTIVE BEAMS PASS BETWEEN SAID BEAM PRODUCING MEANS AND SAID MAIN FOCUSING ELECTRON LENS AND WHICH CONSTITUTE RELATIVELY SPATIALLY DISPLACED INDIVIDUAL PREFOCUSING ELECTRON LENSES FOR THE RESPECTIVE BEAMS EACH OPERATIVE TO PARTIALLY FOCUS THE RESPECTIVE BEAM AND TO COMBINE WITH THE EFFECT OF SAID MAIN FOCUSING ELECTRON LENS FOR FOCUSING THE RESPECTIVE BEAM ON SAID SCREEN.