Single-beam color picture tube employing venetian blind deflection grid

Claim 1

IN AN ELCTRON TUBE FOR REPRODUCING COLOR TELEVISION PICTURES, HAVING FOCUSING AND DEFLECTION MEANS OF THE KIND CUSTOMARILY EMPLOYED IN CONNECTION WITH MONOCHROMATIC PICTURE TUBES, AND HAVING DISPOSED IN AN EVACUATED TUBE STEM A SYSTEM FOR PRODUCING AN ELECTRON BEAM WHICH CAN BE MODULATED AS TO ITS INTENSITY, AND HAVING A PICTURE SCREEN ELECTRODE WHICH IS CONNECTED TO HIGH VOLTAGE AND PROVIDED WITH AT LEAST TWO SUBSTANCES ADAPTED TO LUMINESCE IN DIFFERENT COLORS RESPONSIVE TO ELECTRON IMPACT THEREON, SAID SUBSTANCES BEING DISPOSED ALONG DISCRETE AND REGULARLY DISTRIBUTED AREAS WHICH RESPECTIVELY REPRESENT ELEMENTARY GROUPS, AND ALSO HAVING TWO MUTUALLY SPACED APART GRIDS DISPOSED AHEAD OF THE PICTURE SCREEN ELECTRODE AND PRACTICALLY PARALLEL THERETO, AND FURTHER HAVING MEANS FOR CAUSING THE ELECTRONS TO ENTER PERPENDICULARY INTO THE PLANE OF THE RESPECTIVE GRIDS, WHEREBY SAID ELECTRONS ARE SLOWED DOWN TO EASILY INFLUENCED SLOW ELECTRONS, THE ACCELERATION FIELD OF THE SCREEN ELECTRODE DEFLECTING SAID ELECTRONS FROM THEIR PATHS AT THE SCREEN SIDE AND SIMULTANEOUSLY FOCUSING THE ELECTRONS, AND HAVING COLOR SELECTION MEANS FOR PERIODICALLY AFFECTING THE ACCELERATION OF SAID ELECTRONS SO AS TO CAUSE SUCCESSIVE PICTURING THEREOF UPON THE INDIVIDUAL AREAS OF DIFFERENT COLORS OF THE RESPECTIVE ELEMENTARY GROUPS; THE IMPROVEMENT WHICH IS CHARACTERIZED BY THE PROVISION OF A PLURALITY OF MUTUALLY PARALLEL DISPOSED METALLIC STRIPS WHICH ARE IN THE FASHION OF SLATS OF A VENETIAN BLIND MUTUALLY SPACED APART, SUCH SPACING BEING IN ACCORDANCE WITH A GRID CONSTANT WHICH IS EQUAL TO OR SMALLER THAN THE ELECTRON BEAM DIAMETER, THE RESPECTIVE METAL STRIPS BEING RESPECTIVELY BENT SO AS TO RETAIN THEREBETWEEN SOME CLEARANCE IN THE DIRECTION OF THE TUBE AXIS, SAID VENETIAN BLIND GRID BEING ONE OF SAID TWO MUTUALLY SPACED GRIDS AND BEING DISPOSED DIRECTLY AHEAD OF SAID SCREEN ELECTROD, SAID SCREEN ELECTRODE BEING METAL-BACKED AND THE AREAS OF THE RESPECTIVE ELEMENTARY GROUPS BEING PROVIDED THEREON IN THE FORM OF STRIPS EXTENDING IN PARALLEL WITH THE STRIPS OF SAID VENETIAN BLIND GRID, THE SECOND ONE OF SAID TWO MUTUALLY SPACED APART GRIDS BEING DISPOSED DIRECTLY AHEAD OF SAID VENETIAN BLIND GRID AND SERVING SUBSTANTIALLY SOLELY FOR CAUSING THE ELECTRONS TO ENTER SAID GRID PLANES PERPENDICULARLY, THE DIVISION OF SAID SECOND GRID BEING INDEPENDENT OF THE DIVISION OF SAID VENETIAN BLIND GRID AND ALSO INDEPENDENT OF THE DIVISION OF SAID ELEMENTARY GROUPS.