| 摘要 |
PURPOSE:To restrain the color purity of an image plane from deteriorating, by supsending a shadow mask frame on a panel side wall with a fine strip elastic member, and setting an angle made between the movable part and a tube axis and another angle made between an electron beam and the tube axis, to the specified relationship. CONSTITUTION:A mask frame 17 supporting a shadow mask 15 of a color picture tube is suspended on a stud 10 of the side wall of a panel 1 by a fine strip elastic member 22. At this juncture, when a thermal expansion coefficient of the mask frame 17 at room temperature or in a range of 200 deg.C is set to alphaf, and that of the shadow mask 15 to alpham as well as an angle made between a movable piece part 22a of the elastic member 22 and a tube axis 20 is set to alpha and that made between an electron beam 24 and the tube axis 20 to beta, respectively, they should be set so as to satisfy a relationship of tan (alpha)>alpham/alphaf.tan(90-beta). And, displacement of the electron beam with thermal expansion in the shadow mask is restrained from occurring. Accordingly, a mislanding quantity is reduced, and reduction in chromatic aberration or the like is promotable. |
