| 摘要 |
PURPOSE:To make the face portion flatter thereby to provide the face portion giving nicer impression, by adapting the radii of curvature from the center of the face portion to the ends of the diagonal axis, the horizontal axis, and the vertical axis to be specified values. CONSTITUTION:If the radii of curvature of the internal surface of the face portion in the directions of the vertical axis, the horizontal axis, and the diagonal axis are respectively represented by RV, RH, and RD, and half the maximum effective lengths of the circumferential frame of the internal surface of the face portion in the directions of the vertical axis, the horizontal axis, and the diagonal axis are respectively represented by SV, SH, and SD, then the degree of the variations in the curvature or the differences in the distances in the longitudinal direction of the cathode ray tube between the center of the face portion and the ends of the diagonal axis, the horizontal axis, and the vertical axis are adapted to be respectively as specified by the formulas I to III. Then, it is made possible to provide a cathode ray tube having the ratios of SV to SH to SD made to be substantially 3:4:5 and the face portion made flatter. |
