COLOR PICTURE TUBE HAVING INLINE ELECTRON GUN WITH FOCUS ADJUSTEMENT MEANS

摘要

A color picture tube has a viewing screen and an electron gun for generating and directing three inline electron beams, a center beam and two side beams, toward the screen. The gun includes electrodes that form three focus lenses. A first lens is located in a beam-forming region of the gun. A second lens includes at least one electrode for providing asymmetrically-shaped beams to a third lens. The third lens is a common main focus lens for all three beams. The improvement comprises one of the electrodes of the third lens being shaped to provide a major amount of focus correction for each individual electron beam, and the one electrode of the second lens including means for providing the remaining amounts of focus correction needed to substantially totally correct each individual electron beam.