| 摘要 |
<p>A cathode ray tube with a central axis includes a panel (2) with an inner phosphor screen (3) and a rear portion. The panel has a substantially rectangular effective screen portion with two long sides in a horizontal axis direction, two short sides in a vertical axis direction and four edges in a diagonal axis direction. A funnel (10) is connected to the rear portion of the panel. The funnel sequentially has a body (12) with a large-sized end (12a) and a small-sized end (12b), and a cone portion (14) with a large-sized end (14a) and a small-sized end (14b). The large-sized end of the body is sealed to the rear portion of the panel. The small-sized end of the body meets the large-sized end of the cone portion at a point. The meeting point (16) of the body and the cone portion becomes an inflection point of the funnel. The cone portion has a sectional shape varying from a circle to a non-circle like a rectangle while proceeding from the small sized end to the large sized end such that the cone portion is provided with a curvature radius Rh in the horizontal axis direction, a curvature radius Rv in the vertical axis direction, and a curvature radius Rd in the diagonal axis direction. A neck (8) is sealed to the small-sized end of the cone portion. An electron gun (6) is fitted within the neck to produce electron beams. A deflection yoke (4) is mounted around the cone portion of the funnel. The horizontal, vertical and diagonal curvature radii Rh, Rv and Rd of the cone portion of the funnel satisfy the following condition: Rh < Rv < Rd. <IMAGE></p> |
