Matsushita Electronics Corporation

Osamu Yoshida

Kakuichiro Hosokoshi

This invention concerns an improvement in manufacturing of color picture tubes wherein photosensitive slurry is applied on the inner surface of a face panel of the tube and dried to form a dried slurry, then a shadow mask is secured to the face panel with a specified gap in between, and ultraviolet rays impinge on the dried slurry layer through a path-refracting lens and apertures of said shadow mask so as to form dots on the inner surface. The improvement lies in provision of a light attenuator to control exposure distribution of the ultraviolet rays closely beneath the shadow mask. With this arrangement, sizes of the dots in the edge part of a screen can be made almost equal irrespective of changes of position of the ultraviolet ray source. Consequently, the dots for the three colors in the edge portion of the screen can be made substantially equal in size, and good color balance throughout the picture screen is obtainable.

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Kyoto, Japan

Osamu Yoshida