Abstract: A cathode ray tube is provided which includes a panel having a fluorescent surface formed on an inside surface thereof, a tension type shadow mask fitted to the panel with a gap formed therebetween, and a frame. The frame includes two main frames fixed to the tension type shadow mask under tension, and two subframes fixed respectively to ends of the two main frames. A distance between the two main frames between a center part or portion of the main frame and an edge part or portion. To assemble the frame assembly and the shadow mask, the main frames are compressed, the tension type shadow mask is welded thereto, and the compression applied to the main frames is then released. The invention improves a howling characteristic by reducing a vibratory length of the shadow mask and increasing a natural frequency of the center part or portion of the shadow mask.

Abstract: Panel in a cathode ray tube having a flat outside and a curved inside surfaces, which can provide a perfect flat image at an appropriate distance of view, wherein a condition of 2.48×106(mm2)≦R×CFT≦4.38×106(mm2) is set for the CRT for use as a TV receiver, and a condition of 2.17×105(mm2)≦R×CFT≦6.93×105(mm2) is set for the CRT for use as a monitor, where R is a curvature represented by at least one of vertical, horizontal and diagonal curvatures of the inside surface of the panel and CFT is a center thickness of the panel.

Abstract: Color cathode ray tube including a panel in front portion of the cathode ray tube, and a shadow mask spaced from, and fitted to rear of the panel for selecting a color from electron beams, wherein at least one of an inside surface of the panel and the shadow mask have a curvature structure in which a radius of curvature varies continuously within a fixed ratio range, thereby enhancing a strength and improving howling.