High-definition cathode-ray tube and manufacturing method thereof

Abstract

A color cathode-ray tube, and a method for manufacturing this color cathode-ray tube capable of reducing light/dark line patterns produced while the color cathode-ray tube is operated. Exposing light which has passed through a correction lens made of a continuous lens and a discontinuous lens is irradiated onto a photosensitive film of an inner surface of a face panel of the color cathode-ray tube via a shadow mask so as to expose this photosensitive film, and then while using the exposed photosensitive film as a mask, fluorescent dot patterns are formed on a surface of the face panel. The correction lens having a discontinuous plane owns a plurality of light incident planes, a light projection plane for projecting the light entered into the light incident planes outside this light projection plane, and a plurality of level difference planes arranged between the light incident planes located adjacent to each other. The plural light incident planes are arranged in a matrix form, and enters therein light emitted from an exposing light source, and also refracts the entered light along a desirable direction. Then, the plural level difference planes are provided in such a manner that two sets of the light which have entered into two sets of the light incident planes located adjacent to the level difference plane are continuously projected from the light projection plane with being close to each other.