Abstract: A pair of disc-shaped members of magnetic material each having three through holes for passing the beams emitted from three electron guns R, G and B are arranged in parallel to each other within the glass neck of a color picture tube. An annular permanent magnet is provided on the outer surface of the glass neck at a position nearest to the outer periphery of each of the disc-shaped members of magnetic material. The annular permanent magnet for magnetizing one of the members has an S pole at its part nearer to the outer surface of the glass tube and an N pole at its part farther from the outer surface of the glass tube, while the other annular permanent magnet for magnetizing the other member of magnetic material has N and S poles nearer to and farther from the glass tube respectively.

Abstract: An electron beam focusing structure for a three in-line gun color picture tube comprises a permanent magnet or a focusing coil and a pair of magnetic yokes made of magnetic material high in magnetic permeability and having beam-passing through-holes and being disposed opposite to each other and perpendicular to the axis of the tube, for controlling the focusing magnetic fields generated for the plural electron beams by the permanent magnet or focusing coil in such a manner that the beams converge near the phosphor screen and focused respectively on the phosphor screen. The magnetic yokes are provided with cylindrical magnetic members extending in the axial direction of the tube, the cylindrical magnetic members for the center beam being different in length from the cylindrical magnetic members for the side beams, whereby the effective pole gap lengths for the respective beams between the magnetic yokes are so controlled as to provide optimum focusing fields for the respective beams.

Abstract: An electron gun structure for a pickup tube comprises a cathode lens electrode assembly, a beam disc electrode and a main lens electrode assembly. The main lens electrode assembly includes first and second electrodes adapted to be supplied with different potentials so as to form a bipotential electron lens in the main lens electrode assembly. The beam disc electrode which has a beam limiting hole is adapted to be supplied with a potential not higher than about 2.5 times the lower one of the potentials to be supplied to the first and second electrodes in the main lens electrode assembly.