Color picture tube having an improved expanded focus lens type inline electron gun

Abstract

An improved color picture tube has an inline electron gun for generating and directing three electron beams, a center beam and two side beams, along coplanar paths toward a screen of the tube. The gun includes a main focus lens for focusing the electron beams. The main focus lens is formed by two spaced electrode members each having three separate inline apertures therein. Each electrode also includes a peripheral rim. The peripheral rims of the two electrodes face each other. The apertured portion of each electrode is within a recess set back from the rim. The width of the recess in at least one of the electrodes is wider at the center beam path than at the side beam paths, measured perpendicular to the plane containing the electron beam paths.

Dependencies are inferred from the claim text.