Abstract: A camera tube device for use in, for example, a television camera comprises a cathode emitting electrons, and a first grid and a second grid having respective apertures for converging the electrons emitted from the cathode into a fine electron beam. The aperture of the second grid is sufficiently smaller than that of the first grid and plays an important role for the formation of the electron beam. The electron beam scans a target carrying a charge pattern corresponding to the luminous intensity of an object. Voltages applied to the first and second grids are controlled so as to provide the electron beam quantity corresponding to the luminous intensity of the object forming the charge pattern of the target.

Abstract: A magnetic-focus electrostatic-deflection image pickup tube utilizes a magnetic field for electron beam focusing and an electrostatic field for electron beam deflection. The magnetic field generated by a magnetic focus coil is distributed on the tube axis to have the peak of intensity which is offset toward the electron gun. The electron beam can be deflected and focused to provide a minimized beam spot with less distortion.

Abstract: In an image pickup tube including a cathode, a first grid electrode disposed as a next stage of the cathode and provided with an aperture, a second grid electrode disposed as a next stage of the first grid electrode and provided with an aperture, and a photoconductive target, the first grid electrode is operated by a voltage positive with respect to the cathode. To control the amount of the electron beam of the image pickup tube, a voltage corresponding to a signal current obtained from the photoconductive target of the image pickup tube or to a return beam from the photoconductive target is applied to the second grid electrode in such a manner that a polarity of the applied voltage is opposite to a polarity of a signal charge generated on the photoconductive target.

Abstract: A magnetic focusing and electrostatic deflecting image pickup tube comprises electrostatic deflection electrodes each constituted by a straight arrow pattern yoke composed of straight line segments arrayed in a linear zigzag pattern. The pattern yoke has a twist angle set at a value not greater than 105.degree.. An average value of angles formed by each upper apex and two lower apices adjacent to the upper apex of the zigzag pattern yoke with reference to the axis of the tube lies within a range of 116.degree. to 127.degree..

Abstract: A camera tube device for use in a television camera comprises an electron gun including a cathode electrode for emission of an electron beam, and first and second grid electrodes respectively having apertures for controlling the diameter of the electron beam. The aperture of the second grid electrode is sufficiently smaller than the aperture of the first grid electrode. The first grid electrode is applied with a positive voltage relative to the cathode electrode and the second grid electrode is applied with a positive voltage relative to the cathode electrode which is higher than that applied to the first grid electrode. The positive voltage applied to the first grid electrode has such a value that forms the electron beam having passed through the aperture of the first grid electrode into a laminar flow beam.

Abstract: An electron beam focusing lens comprises at least two cylindrical electrodes one of which is to be applied with a high potential and the other of which is to be applied with a low potential. A plate electrode having an aperture at a central portion thereof is provided at an end face of the high-potential cylindrical electrode opposite to the low-potential cylindrical electrode. The plate electrode may be of a circularly curved shape which is projected toward the low-potential cylindrical electrode between the outer and inner circumference of the plate electrode.

Abstract: An electron gun for a television camera tube comprises a cathode for emission of electrons, a first grid disposed subsequently to the cathode and having a first aperture supplied with a positive voltage relative to the cathode, a second grid disposed subsequently to the first grid and having a second aperture supplied with a higher positive voltage than that supplied to the first grid, and an intermediate grid interposed between the first and second grids and having a hole. The intermediate grid forms a divergent electron lens near the first aperture between the first and second grids.

Abstract: An electron gun is disclosed which includes a thermionic cathode for emitting an electron beam, a grid having a first aperture for controlling the diameter of the electron beam, and an anode having a second aperture for catching a part of the electron beam having passed through the first aperture; and in which the diameter of the first aperture is smaller than or equal to the diameter of the second aperture, and the grid and the anode are applied with positive potentials relative to a cathode potential, for example, with a voltage of 5 to tens of volts and a voltage of 100 to 500 volts, respectively, to form a uniform axial field between the grid and the anode, thereby generating a laminar flow electron beam having a constant current density.

Abstract: A television camera tube with electrostatic focusing comprising a triode section at the first stage having a cathode a first grid and a second grid, an electrostatic focusing lens section at the next stage having a third, fourth and fifth grids of cylindrical electrode configuration, and a sixth grid with mesh electrode configuration at the last stage, these electrodes being coaxially arranged in a cylindrical glass envelope, the length of the fourth grid is greater than 1.15 times the inner diameter thereof but equal to or smaller than 2.30 times the inner diameter thereof.

Abstract: A vidicon type camera tube comprising a beam current control section including a thermionic cathode, a first grid having an aperture of diameter d.sub.1, a second grid having an aperture of diameter d.sub.2 and a beam disc having a diaphragm of diameter d.sub.3 disposed at a distance of l along the tube axis from the second grid. The tube further comprises a main lens section constituted of cylindrical electrodes. The diameters d.sub.1, d.sub.2 and d.sub.3 and the distance l are so determined that the value of (d.sub.2 /l)(d.sub.3 /d.sub.1).sup.2 may lie in the range where the difference of the effective cathode loading is positive.

Abstract: A television camera tube with electrostatic focusing and magnetic deflection comprises in an cylindrical envelope a beam current control, a main lens section and a sixth grid in the form of a mesh electrode. The beam current control section includes a cathode, a first grid and a second grid with an electron beam limiting diaphragm in this order. The main lens section includes third, fourth and fifth grids in the form of cylindrical electrodes disposed in this order. Around the cylindrical envelope is mounted a magnetic deflection coil whose length along the envelope axis is 0.18 to 0.40 times the distance from the beam limiting diaphragm to the mesh electrode.