Hitachi, Ltd.

Fumiaki Yonai

Hiroshi Yoshioka

Eiichi Yamazaki

Masaaki Yamauchi

Takashi Fujimura

Michio Tsukii

Ryoji Hirai

Takumi Karasawa

Akira Kotoyori

Eiichi Nishiyama

Takashi Atobe

Kunio Shimada

In a proposed color cathode-ray tube with deflection yoke, adjustment of static convergence and purity is performed by controlling the polarities and magnetization forces of a plurality of pole pieces made of metal alloy circumferentially held around the outer periphery. Tap bolts pressing the external wall of a funnel nearly in the perpendicular direction are so disposed on a deflection yoke mounting member as to be adjacent to the funnel of the color cathode-ray tube. The tap bolts press the funnel to fix the deflection yoke.

Color cathode-ray tube having deflection yoke

A color picture tube of shadow mask type includes a faceplate panel mounted on the tube. The faceplate panel has curvatures along its major and minor axes, respectively. When the outer surface contour of the faceplate panel is represented by a three-dimensional expression in the orthogonal coordinate system defined by the X-axis corresponding to the major axis, the Y-axis corresponding to minor axis, and the Z-axis corresponding to the axis of the tube, respectively, curved contours Z.sub.x and Z.sub.y of the faceplate panel along the major axis and the minor axis are so realized as to be approximated by Z.sub.x A.sub.1 X.sup.2 +A.sub.2 X.sup.4 and Z.sub.y =A.sub.3 Y.sup.2 +A.sub.4 Y.sup.4, respecvtively, where X and Y represent distances from the center of the faceplate panel along the X-axis and the Y-axis, respectively, and wherein the constants A.sub.1, A.sub.2, A.sub.3 and A.sub.4 are so selected that the conditions that 0.3.ltoreq.P.sub.x (X=X.sub.1).ltoreq.0.6 and 0.95.ltoreq.P.sub.y (Y=Y.sub.2).ltoreq.1.0 where P.sub.x =A.sub.1 X.sup.2 /(A.sub.1 X.sup.2 +A.sub.2 X.sup.4), P.sub.y =A.sub.3 Y.sup.2 /(A.sub.3 Y.sup.2 +A.sub.4 Y.sup.4) are satisfied at points X.sub.1 and Y.sub.2 on the boundaries defining an effective picture area on the faceplate. Further, the contours of the effective picture area defining boundaries extending in parallel with short and long sides of the outer surface of the faceplate panel are so curved as to have approximately equal curvature, the radius R (mm) of which on the boundary is so selected as to satisfy the condition that 1.5 (42.5 V+45.0).ltoreq.R.ltoreq.2.0 (42.5 V+45.0), where V represents the diagonal length of the effective picture area.

Color picture tube of shadow mask type with particular faceplate panel

In exposure apparatus adapted to expose the phosphor on the face plate of a colour picture tube provided with a slot type colour selection electrode of the type comprising an exposure light source and a correction lens disposed between the light source and the colour selection electrode the exposure light source and the correction lens are moved with respect to the colour selection electrode.

Exposure apparatus

Growing community of inventors

Mobara, Japan

Fumiaki Yonai