PURPOSE: To obtain uniform degree of allowance between phosphor dot and electron beam trios regardless of any axial position by forming the phosphor dot trio consisting of almost round phosphor dots even when an electron beam passing hole section is located in any position within the effective area of a panel.

CONSTITUTION: As shown in the figure, since allowance can be generated almost averagely in both the vertical axis Y and horizontal axis X directions from a viewpoint of landing by making phosphor dot trios 13R, 13G, and 13B almost round, allowance is reserved as the total color picture tube by the effects of ΔΔ r characteristics, α characteristics that are used to indicate the characteristics of the color picture tube, shape error characteristics, production scattering, and terrestial magnetism even when the balance is lost in the vertical axis Y, horizontal axis X, and diagonal axis P and Q directions. Besides, when an opening section for the phosphor dots and the phosphor dots are formed, even in the exposure process, the unbalance of the effect of the total and partial shadows of an exposure light source is reduced in each axial direction and both dot omission and overlapping are hard to take place.