CATHODE-RAY TUBE

摘要

The distribution of geomagnetism on the earth is complicated. Even if an internal magnetic shield and a mask are installed on a flat screen color CRT, it is difficult to make an effective compensation for the displacement of the point that the electron beam reaches on the fluorescent screen due to the external magnetism such as the geomagnetism, depending on the place where the CRT is installed on the earth. As a solution for this problem, a stripe color cathode-ray tube having a big tolerance for vertical difference in the point that the electron beam reaches is used. A gap of nonmagnetic or hard magnetic material or an air gap is provided between the mask frame and the internal magnetic shield so as to allow the magnetic flux flowing into the inside of the mask from the frame (from the edge of the mask of some type) of the internal magnetic shield to flow outside the mask.