Patent ID: 7471894

Claim:
A manufacturing method of a color cathode ray tube comprising a panel portion which includes a phosphor screen on which a black matrix film having a plurality of opening portions and three kinds of phosphor pixels which are arranged in the opening portions of the black matrix film are formed on an inner surface thereof, and a shadow mask which is arranged to face the phosphor screen formed on the inner surface of the panel portion and includes a large number of electron beam passing apertures, wherein a step for forming the black matrix film comprises an exposure step of first phosphor pixel holes, an exposure step of second phosphor pixel holes, and an exposure step of third phosphor pixel holes, the exposure step of the first phosphor pixel holes performs the exposure by arranging a grading filter between the inner surface of the panel portion and an exposure light source with a first distance spaced apart from the exposure light source, the exposure step of the second phosphor pixel holes performs the exposure by arranging the grading filter between the inner surface of the panel portion and the exposure light source with a second distance spaced apart from the exposure light source, the exposure step of the third phosphor pixel holes performs the exposure by arranging the grading filter between the inner surface of the panel portion and the exposure light source with a third distance spaced apart from the exposure light source, and at least one of the first distance, the second distance and the third distance is made different from other distance.