Method for manufacture of color television picture tubes using rotating light source

摘要

The invention discloses a method and apparatus for manufacture of color television picture tubes of the type having a shadow mask with a multiplicity of slots, and more particularly for selectively exposing a light sensitive film uniformly coated over the inner surface of a face-panel in order to form the temporary dots or strips. The exposure light source is rotated in the form of a ring while it is displaced relative to the light sensitive film in the longitudinal direction of the slots in a shadow mask, whereby the spacing in the longitudinal direction between the adjacent exposed areas or light images projected may be advantageously reduced without reducing the spacing in the longitudinal direction between the adjacent slots in the shadow mask; that is, the width of the bridge therebetween, so that the color television picture tubes with excellent brightness and contrast characteristics may be provided without adversely affecting the mechanical strength of the shadow mask.