Abstract: The novel spot-knocking method for an electron gun mount assembly in an evacuated CRT comprises applying a spot knocking voltage between a first and second anode, and a first focus electrode with the remaining gun elements including a heater, a cathode, a control electrode, a screen electrode and a second focus electrode electrically floating.

Abstract: The novel spot-knocking method for an electron gun mount assembly having a gun axis in an evacuated CRT comprises interconnecting a heater, a cathode, a control electrode and a screen electrode. Then, providing a magnetic field along the gun axis while applying spot-knocking voltages between an anode and the interconnected gun elements. The magnetic field facilitates the initiation of arcs parallel to the magnetic field and to the gun axis and between the adjacent gun elements, and inhibits the initiation of arcs in directions transverse to the magnetic field and the gun axis.

Abstract: A novel electron gun for a cathode-ray tube includes at least one and preferably three cathode assemblies and at least four successive electrodes longitudinally spaced from the cathode assemblies. Each of the electrodes has at least one and preferably three electron beam apertures therethrough. The cathode assemblies and two of the electrodes are attached to a ceramic support member which is the sole supporting interconnection therebetween. A third electrode of the four successive electrodes has a distal electrode member and a proximal electrode member. The proximal member also is attached to the ceramic support member to form a first gun module. A second gun module includes a fourth electrode of the four successive electrodes which is in spaced relation to the distal member of the third electrode. The fourth electrode and the distal member of the third electrode are interconnected by a pair of insulative spacers.

Abstract: An inline electron gun for generating and directing three electron beams, a center beam and two side beams, along initially coplanar paths includes an electrostatic main focusing lens for focusing the electron beams. The main focusing lens is formed by two spaced electrodes, each having three separate inline apertures therein. A first of the main focusing lens electrodes includes a first cylindrical portion having a diameter larger than the sum of the diameters of the apertures therein. A second of the main focusing lens electrodes includes a second cylindrical portion having a diameter larger than the diameter of the first cylindrical portion of the first main focusing lens electrode. At least part of the first cylindrical portion of the first main focusing lens electrode is located within the second cylindrical portion of the second main focusing lens electrode. The largest component of the main focusing lens is established by the first and second cylindrical portions.

Abstract: The present invention is an improvement in an electron gun for use in a cathode ray tube. Such gun includes at least one cathode and a plurality of electrodes spaced from the cathode. At least two of the electrodes form a main focusing lens and the electrode nearest the cathode which forms the main focusing lens includes extrusions about an aperture therein. The improvement comprises means located at the end of the gun opposite the cathode for blocking the exit from the gun of electrons emitted from the extrusions.

Abstract: The novel method of electrically processing a completed and operative CRT comprises (A) heating the portions of the focus electrode that face a high-voltage electrode at temperatures above about 700.degree. C. and simultaneously (B) spot-knocking the heated portions of the focus electrode. The novel method can be applied during the initial processing of the CRT and/or subsequently during a reprocessing procedure.

Abstract: CRT (cathode-ray tube) comprises an evacuated glass envelope, an electron-gun mount assembly housed in the envelope, the electrodes of said envelope being confined by closely-spaced glass surfaces, and an insulative coating on said glass surfaces opposite electrodes of said mount assembly. The insulative coating is a substantially-continuous, noncrystalline film of a nonionic organic polymeric material.

Abstract: A structure and method is proposed for eliminating so-called halo-blocked apertures in color picture tubes. The halo-blocked apertures are caused by insulative negatively-charged particles attached to the gas-sorbing conductive getter metal film on the inside surface of the shadow mask which deflect the transmitting portions of an electron beam. The structure comprises a source within the tube for depositing a gas-sorbing conductive getter metal overlay on the charged particle to render the particle conductive so that the particle cannot deflect the beam.

Abstract: Before a CRT is tipped off following exhaustion of gases to a low pressure, at least a portion of one of the electrodes of the mount assembly (e.g., the grid electrode facing the anode) is heated to high temperatures, preferably about 700.degree. to 800.degree. C., in an atmosphere having a partial pressure of oxygen.

Abstract: The present invention provides an improvement in shadow mask type color picture tubes. The improvement comprises a ferromagnetic member located within a tube and means for holding the ferromagnetic member within the tube. The invention also encompasses a method of utilizing the ferromagnetic member to remove particles from a shadow mask of a color picture tube. The method includes the use of a magnet to release the ferromagnetic member from the holding means and to move the ferromagnetic member over a surface of the shadow mask.

Abstract: A CRT comprising an evacuated envelope having an electrically-insulating neck and a beaded electron-gun mount assembly in the neck. The beads of the assembly are closely spaced from the inner surface of the neck. At least a portion of the surfaces of the beads opposite the neck is electrically conducting.

Abstract: A method for coating a selected portion of the internal surface of the neck of a CRT having a beaded electron-gun mount assembly housed therein. The method comprises providing in the neck at least one source of chromium metal spaced from and within line-of-sight of at least a portion of the neck surface opposite each bead. The CRT is evacuated to a low gas pressure and then chromium metal vapor is released from each source towards the neck surface, whereby chromium metal deposits on the neck surface.

Abstract: A method of reducing the absorption losses in an optical fiber by irradiating the optical fiber with ultraviolet light at a reduced pressure and elevated temperature.

Abstract: A mercury arc lamp envelope is made of high purity synthetic fused silica which contains total metallic impurities of less than one part per million by weight and OH radical content of less than five parts per million by weight. Lamps having envelopes made from this material show little or no devitrification after 1000 hours of operation.