Abstract: In an electron gun for use in a cathode ray tube of the class wherein a main electron lens system is constituted by a plurality of discrete electron lens systems, the plurality of electron lens systems are of the unipotential type and the intensity of the preceding lens system is made larger than that of the succeeding lens system.

Abstract: In light exposure apparatus wherein the face plate of a color picture tube is exposed to the light from a light source through a swinging illumination intensity correcting filter, a correction lens and a color selection electrode, the effective surface of the illumination intensity correcting filter comprises a plurality of regions having different light transmitting ability, and the effect of the optical characteristics at the interfaces between the regions is arranged and substantially eliminated by the swinging motion of the illumination intensity correcting filter.

Abstract: In a correction lens wherein the effective surface thereof has at least a lens member having no island shaped portion, said member being defined by the step shaped border line never closing by themselves to form an island shaped lens segment on said correction lens surface.

Abstract: A fluorescent screen including a plurality of parallel stripes of three colour phosphors is prepared by projecting light from a linear light source positioned in parallel with the stripes on photosensitive substances coated on the inner surface of the panel through a plurality of stripe shaped perforations of a colour selecting member, each divided into a plurality of slit shaped sections by means of bridges. The linear light source is constituted by reciprocating a point light source in parallel with the stripe shaped perforations.