Cathode-ray tube having electron gun with three focus lenses

Abstract

An inline electron gun, for use in a cathode-ray tube, comprises four electrode means. The first electrode means forms three inline electron beams including a center beam and two outer beams. The second electrode means pre-focuses each of the electron beams individually and converges the two outer beams toward the center beam to cross-over each other within the electron gun. The third electrode means provides a common main focus lens for the three electron beams at the crossover of the beams. And, the fourth electrode means provides a common post-focusing lens for the three electron beams which causes the two outer beams to converge with the center beam near a screen of the tube.

Dependencies are inferred from the claim text.