Method and device for heating the electrodes of an electron gun during its manufacture
AssigneeVideocolor
InventorGiuliano Giudici
Life of this patent
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Abstract
Method for heating the first electrodes of electrostatic lenses of the bi-potential type of an electron gun forming part of a cathode ray tube, this heating being performed during manufacture of the tube and wherein the first electrodes of the two lenses are brought to a same potential and the second electrodes are also brought to a same potential but at a value different from that of the first one and the electrons produced by the gun are used for heating the first electrode of each lens at its end adjacent to the second electrode of this same lens.
Claims10
Method for heating the first electrodes of two electrostatic lenses of the bi-potential types of an electron gun forming part of a cathode ray tube, this heating being carried out during the manufacture of the tube, the first electrodes of these two lenses being brought to the same potential and the second electrodes also being brought to a same potential, but of a value different to that of the first, method in which, for the heating, use is made of the electrons produced by the gun, wherein the heating of the first electrode of each lens is localized at its end adjacent to the second electrode of this same lens.
Method for heating the first electrodes of two electrostatic lenses of the bi-potential type of an electron gun forming part of a cathode ray tube, this heating being carried out during manufacture of the tube, the first electrodes of these two lenses being raised to a same potential and the second electrodes also being raised to a same potential but of a value different to that of the first one, method in which for the heating, use is made of electrons produced by the gun, wherein the heating of the first electrode of each lens being localized at its end adjacent to the second electrode of this same lens, to localize the heating on the end of the first electrode of the first lens which is adjacent to the second electrode of this same lens is applied on this second electrode a negative potential sufficiently high in absolute value to prevent the electrons from crossing through this second electrode, and wherein to localize the heating on the end of the first electrode of the second lens adjacent to the second electrode of this same lens, on the second electrodes of the two lenses are applied a same negative potential which, in absolute value, is sufficiently low so that the electrons can cross through the second electrode of the first lens but sufficiently high so that the second electrode of the second lens repells the electrons.
Dependencies are inferred from the claim text.