CATHODE-RAY TUBE

摘要

A small haze around the spot on the display screen in the corners and at the edge of the display screen is obtained by causing the first grid to form a multipole lens in cooperation with the cathode, which lens mainly is a first quadrupole lens and in cooperation with the second grid also forms a multipole lens which is also a mainly second quadrupole lens and which is rotated 90.degree. with respect to the first quadrupole lens. Such a system of lenses in the first grid can be formed, for example, by giving the aperture in the first grid an elongate cross section both on the side of the cathode and on the side of the second grid, the long axis of said elongate cross-section on the side of the cathode extending substantially at right angles to the long axis of the elongate cross-section on the side of the second grid.