| 摘要 |
PURPOSE:To lower the electricity consumption of a color picture receiving apparatus without deteriorating its picture quality, by forming its picture tube with an integrally united body of a neck portion having a circular cross-section and a funnel portion whose cross-section changes from a circle to a laterally long ellipse gradually. CONSTITUTION:A funnel portion 10, to be sealed to a neck portion 9 having a circular cross-section, is formed into configurations surrounded by an elliptical curve 5 which is in turn formed of three arcs, namely, the first arc having a radius R1 and its center at a point P on the (y) axis, the second arc having a radius R3 and its center at a point S on the (x) axis, and the third arc having a radius R2 and its center at a point Q. A glass tube body is formed by making the increment rate of its vertical length-to-horizontal length ratio large at the small diameter side thereof but small at the large diameter side thereof. In this constitution, the space distance in the (y) axis direction can be made short. Accordingly, compared with a picture tube whose funnel portion has a circular cross-section, the electricity consumption can be considerably cut down. In addition, owing to the circular cross-section of the neck portion, the picture quality is prevented from deterioration. |
