Cathode ray tube

Claim 1

A CATHODE RAY TUBE COMPRISING A LUMINESCENT SCREEN AND AN ELECTRON GUN ADAPTED TO PROJECT AN ELECTRON BEAM ONTO SAID SCREEN, SAID GUN COMPRISING A PLURALITY OF ELECTRODES ALIGNED ALONG A CENTRAL AXIS, SAID ELECTRODES INCLUDING A CATHODE HAVING A PLANAR ELECTRON EMITTING PORTION, A CONTROL ELECTRODE INCLUDING A PLANAR PORTION HAVING A SUBDIVIDED BEAM CONTROL APERTURE OF GIVEN DIAMETER OPPOSITE SAID CATHODE PORTION, AND ELECTRON ACCELERATING ELECTRODE FOR ACCELERATING ELECTRONS EMITTED FROM SAID CATHODE PORTION INTO SEPARATE STREAMS PASSING THROUGH THE SUBDIVISIONS OF SAID APERTURE, SAID ACCELERATING ELECTRODE HAVING A SINGLE APERTURE OF GIVEN DIAMETER SPACED FROM AND COAXIAL WITH SAID BEAM CONTROL APERTURE, MEANS INCLUDING A LOW POTENTIAL FIELD-FORMING ELECTRODE ADJACENT TO SAID CONTROL ELECTRODE ON THE SIDE THEREOF OPPOSITE FROM SAID CATHODE AND HAVING A SINGLE APERTURE OF SUBSTANTIALLY GREATER DIAMETER THAN SAID GIVEN DIAMETERS COAXIAL WITH SAID BEAM CONTROL APERTURE FOR CREATING BETWEEN SAID CONTROL AND ACCELERATING ELECTRODES A CONVERGENT ELECTRIC FIELD FOR INDIVIDUALLY CONVERGING AND FOCUSING EACH OF SAID ELECTRON STREAMS TO A COMMON CROSSOVER ON SAID CENTRAL AXIS, AND MEANS FOR CONVERGING AND FOCUSING SAID STREAMS BETWEEN SAID CROSSOVER AND SAID SCREEN TO IMAGE SAID CROSSOVER ON SAID SCREEN.