Hitachi, Ltd.

Takehiko Nishimoto

Takeshi Nakayama

Kuniharu Osakabe

Machio Kawashima

Kozi Takahashi

A color picture tube having a shadow mask is disclosed in which, with a view to making occurrence of moire imperceptible, electron beam transmissive apertures of the shadow mask are formed in such an array that a plurality of trains of the electron beam transmissive apertures each arrayed in the vertical direction with a pitch P.sub.y are juxtaposed to one another, wherein, assuming that the order of the harmonics is represented by n and m is an odd number smaller than 2n, there exist the relations (n-0.5)P.sub.l .ltoreq.P.sub.y .ltoreq.(n+0.05)P.sub.l and (m-0.35)P.sub.y /2n.ltoreq..DELTA.y.ltoreq.(m+0.35)P.sub.y /2n among the pitch P.sub.y, pitch P.sub.l of scanning lines and vertical deviation .DELTA.y between two adjacent apertures in the horizontal direction.

Slotted shadow mask having apertures spaced to minimize moire

A color picture tube having a shadow mask provided with a plurality of vertical aperture rows arranged as horizontally juxtaposed to one another, each vertical row comprising the electron beam transmissive apertures vertically arranged in line with a predetermined pitch P.sub.y. With a view to making possibly occurring moires imperceptible, the arrangement of the apertures are made such that, when spatial deviation in the vertical positions between any two apertures in the horizontally adjacent aperture rows is represented by .DELTA.y, there may be included combinations of at least two different type aperture rows of different deviations .DELTA.y which satisfy the following condition ##EQU1## at least when n is equal to 1, 2, 3 or 4 and k is an odd number smaller than 2n.

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Kodaira, Japan

Takehiko Nishimoto