| 摘要 |
PURPOSE:To improve the beam transmission factor of a shadow mask, satisfying the fineness of a screen by forming the hole of the shadow mask into a vertically long ellipse and a three-color phosphor dot which is similar to the ellipse. CONSTITUTION:A phosphor dot 5 is formed into an ellipse. The upper and lower semicircles 3 and 4 are circumscribed with phosphors with mutually different luminous colors at the two points 6 and 7 of each circumference section and the lines which are connected to the center of the circumcircles are formed into an equilateral triangel containing the contacts 6 and 7. Besides, they form a phosphor screen so as to share two sides 8 and 9 with the horizontal adjacent dot. The hole 10 of a shadow mask is arranged to coincide with the center of the central dot of a three-color phophor dot trio and the angle made by the center line of the hole with the horizontal line ranges within 33 to 43 degrees. For this purpose, even when high density information is displayed, the beam transmission factor of the shadow mask can be improved and high brightness display be performed. |
