Method and apparatus for exposure of phosphor screen

摘要

An exposure method and apparatus for forming phosphor stripes or black matrix stripes on the inner surface of a face plate of a stripe phosphor screen type color picture tube or CRT (cathode-ray tube), in which a single linear light source is used as the exposure light source, and a prism device including many juxtaposed prisms is disposed between the linear light source and the face plate. The taper angle of the prisms is continuously changed so that the single linear light source can be observed as a plurality of discontinuous virtual linear light sources at whatever point on the inner surface of the face plate, and the virtual linear light sources have a most suitable center-to-center distance at individual positions on the face plate. The above arrangement eliminates the necessity for drive means for moving the linear light source, and a phosphor screen having three color phosphor stripes of satisfactorily uniform width can be formed on the entire inner surface of the face plate with use of the single linear light source.