Abstract: A cathode-ray tube comprises an evacuated envelope with a substantially rectangular faceplate panel and implosion protection structure disposed around the periphery of the panel to apply a compressive force thereto. The implosion protection structure includes a tube-contacting portion and an overlapping portion extending at least partially along the tube-contacting portion to provide a double thickness of material to increase the effective cross-sectional area of the implosion protection structure. The implosion protection structure is improved by at least one opening formed through one of the portions thereof. Mounting lugs overlie the opening in the one portion of the implosion protection structure and are secured to the other portion of the structure bounded within the opening. A method of securing the mounting lugs also is disclosed.

Abstract: An apparatus for fusing a polymer powder deposited on a surface of a faceplate panel of a cathode-ray tube comprises a housing having a faceplate support surface and enclosing a chamber. A shutter adjacent to the panel support surface separates the faceplate panel from the chamber. A reservoir for holding a solvent is within the chamber and at least one piezoelectric transducer communicates with the reservoir for atomizing the solvent to create a fog. A fan within the chamber distributes the fog onto the polymer powder. A method for fusing the polymer powder onto the faceplate panel also is described.

Abstract: An automatic gain control circuit includes an amplifier, the gain of which is to be controlled, and an input terminal for receiving an analog input signal. A first signal path is arranged between the input terminal and the amplifier and includes a controllable switch and a first filter. A second signal path is responsive to the input terminal and includes an analog-to-digital converter for providing digital signals representative of levels of the analog input signal. A signal processor receives the digital signals and provides control signals. A pulse width modulator receives the control signals and provides a pulse width modulated signal, the width of which varies in accordance with the digital signals, to the controllable switch.

Abstract: An improved color picture tube includes an evacuated envelope having a rectangular faceplate panel. The panel includes a viewing screen on an inner surface thereof and a shadow mask assembly mounted therein by support means located at the four corners of the panel. The shadow mask assembly includes an apertured shadow mask and a peripheral frame to which the mask is attached. The frame is formed by four sections that are welded together at their ends. Two of the sections are longer than the other two sections and are constructed of a material having a different coefficient of thermal expansion than that of the other two sections. The frame reduces electron beam misregister with elements of the screen.

Abstract: A cathode-ray tube comprises an evacuated envelope having a faceplate panel with a mold-match line. A luminescent screen is disposed on an inner surface of the panel. The envelope further includes a funnel and a neck portion. The funnel is joined to the panel. An electron gun, for generating and directing at least one electron beam toward the screen, is located in the neck portion. A shrinkfit implosion protection band is fitted on the periphery of the panel to apply a compressive force thereto as a result of the tension of the band. The band includes a double thickness of material, a section of which extends forward of the mold-match line. The band is improved over prior bands by adjusting the effective sectional area of the double thickness portion to a value appropriate to provide deformation compensation to the faceplate panel, thereby maintaining register of the electron beam on the screen.

Abstract: A cathode-ray tube comprises an evacuated envelope which includes a faceplate panel joined to a funnel. A shrinkfit implosion protection band of at least one strip of metal, having oppositely disposed ends, is secured together at a connective joint to form a loop with cold dimensions slightly smaller than the periphery of the panel prior to application of the band. The band has a given sectional area with at least one opening formed therethrough. The band is fitted around the periphery of the panel to apply a compressive force thereto, as a result of the tension of the band. The band is improved by providing at least one slot within the band and in communication with the opening, to reduce the sectional area of the band sufficiently to lower the tension of the band below the minimum design limit of the connective joint.

Abstract: The invention relates to a method for manufacturing a phosphor screen on an inner surface of a CRT panel, having a faceplate, a blend radius, and a sidewall. The method includes the steps of depositing at least one phosphor layer (R, G, B), containing a binder, on the inner surface of the faceplate, and then coating the phosphor layer, the blend radius, and at least a portion of the sidewall with a filming material. The coating of the filming material is dried to form a film. The film, or at least that portion thereof overlying the blend radius and the side wall, is contacted with an adhesion-promoting, blister-reducing solution which contains operable quantities of silica particles, a low vapor pressure alcohol and deionized water. A metal layer is deposited on the film, and the film and the binder contained in the phosphor layer are volatilized.

Abstract: A solution for making a wear-resistant conductive contact patch for a faceplate panel of a color CRT which facilitates the electrophotographic manufacturing of a luminescent screen on the panel consists essentially of, in weight percent, solvent 22 to 70, conductive material 62 to 21, and the balance being other compatible additives.

Abstract: A color CRT assembly comprises a tube having an external magnetic deflection yoke thereon. The tube includes an evacuated envelope with a substantially rectangular faceplate panel and a tubular neck connected by a funnel having a rectangular open end sealed to the faceplate panel. A three color phosphor screen is carried on an inner surface of the faceplate panel and a color selection electrode is mounted in spaced relation therefrom. An electronic gun is disposed within the neck of the tube for generating and directing at least one electron beam to the screen. The magnetic deflection yoke is located on the tube, in the region of the funnel-to-neck junction of the envelope, for subjecting the beam to magnetic fields which cause the beam to scan a rectangular raster over the screen. The assembly is improved by the inclusion, in the funnel, of a quantity of glass which attenuates x-radiation from the tube. The quantity of glass is disposed adjacent to the yoke, on the faceplate side thereof.

Abstract: The method of electrophotographically manufacturing a luminescent screen on a substrate of a color CRT, according to the present invention, includes the steps of forming a photoreceptor by sequentially coating the substrate to form a conductive layer and an overcoating of a photoconductive layer, establishing an electrostatic charge on the photoconductive layer, and exposing selected areas of the photoconductive layer to visible light to affect the charge thereon. Then the photoconductive layer is developed by the application of suitable triboelectrically charged, dry-powdered screen structure materials. The improved process provides at least one wear-resistant, conductive contact patch on a peripheral portion of a surface of the substrate. The contact patch has a first portion which underlies at least one of the layers of the photoreceptor and is in electrical contact with the conductive layer, and a second portion which extends from the photoreceptor.

Abstract: A method for manufacturing a metallic, luminescent screen for a CRT includes the steps of: depositing at least one phosphor layer on an inner surface of a faceplate of a panel, to form the luminescent screen; preheating the panel containing the screen to a temperature in excess of a minimum film-forming temperature; and depositing an aqueous emulsion of at least one acrylic film-forming resin onto a screen and drying said emulsion to form the film. Then, a metallic coating is deposited onto the film and the panel bearing the metallized screen is sealed to a funnel by heating the panel and funnel through a sealing cycle. The sealing cycle has predetermined rates of temperature increase and includes a temperature range within which the film is volatilized. The rate of temperature increase within the volatilization range is less than the rate of temperature increase in other portions of the sealing cycle.

Abstract: The method of electrophotographically manufacturing a luminescent screen assembly on a substrate for use within a CRT, according to the present invention, includes the steps of: forming a conductive layer on the substrate; overcoating the conductive layer with a photoconductive solution comprising an organic polymeric material, a suitable photoconductive dye, a plasticizer and a solvent to form a photoconductive layer; and, then, establishing an electrostatic charge on the photoconductive layer. Selected areas of the photoconductive layer are exposed to visible light to affect the charge thereon, and the photoconductive layer is developed with charged screen structure material. The improved method utilizes a dialkyl phthalate plasticizer which is selected from the group consisting of dibutylphthalate (DBP), dioctylphthalate (DOP), and diundecylphthalate (DUP).

Abstract: A method of electrophotographically manufacturing a luminescent screen on an interior concave surface of a CRT faceplate panel having a major axis with a first center of curvature and a minor axis with a second center of curvature, the method including the steps of utilizing a charging apparatus for uniformly charging a photoconductive layer disposed on the concave surface of the faceplate panel by providing a corona voltage from a corona generator to at least one corona charger which has an arcuately-shaped charging electrode, the corona charger has a center of curvature substantially concentric with a center of curvature of the concave surface of the panel, a support arm attached to the corona charger is pivotably located at the other center of curvature, the corona charger substantially conforms to, and is spaced from the photoconductive layer on the concave surface, and moving the corona charger across the concave surface.

Abstract: The improved color picture tube includes an evacuated glass envelope having a rectangular faceplate panel with two long sides and two short sides. The panel includes a major axis paralleling the two long sides, a minor axis paralleling the two short sides and two diagonals that extend between opposing corners of the panel. The panel includes a shadow mask assembly mounted therein by support means that are located at the corners of the panel. The support means at each of the spaced positions includes a stud attached to the glass envelope and a spring having an aperture therein engaging the stud. The improvement comprises the studs being located slightly off of the diagonals of the panel between the diagonals and the major axis.

Abstract: The present invention provides an improvement in a cathode-ray tube that includes a rectangular faceplate having two long sides and two short sides wherein the ratio of the length of the long sides to the length of the short sides is approximately 16 to 9. The tube includes a major axis which parallels the two long sides and a minor axis which parallels the two short sides. The improvement comprises the ratio of the equivalent radius of the faceplate curvature along the major axis to the equivalent radius of the faceplate curvature along the minor axis being in the approximate range of 1.5 to 1.6, the ratio of the equivalent radius of the faceplate curvature along the long sides of the faceplate to the equivalent radius of faceplate curvature along the major axis being in the approximate range of 1.12 to 1.

Abstract: The present invention relates to a method for making a viewing screen structure for a cathode-ray tube. The method includes the steps of coating a support surface with a film of a polymeric material, a suitable dichromate and a sensitizer therefor which is a chromium ion migration enhancer having a reduced sensitivity to thermal and dark hardening; exposing the film to an image in the form of radiant energy until the solubility of the irradiated regions thereof is selectively altered, thereby producing in the film regions of greater solubility and regions of lesser solubility; removing those regions of the film with greater solubility to bare portions of the underlying support surface while retaining those regions of the film with lesser solubility. The bare portions of the support surface and the retained film regions are overcoated with a composition of light-absorbing material which is adherent to the support surface.

Abstract: A variable width pulse generator includes a plurality of logic stages which are coupled in cascade. Each stage is arranged to select one of a plurality of clock signals of differing phase applied thereto responsive to particular bits of a data word defining the pulse width. All of the stages are initially disabled by a precharge pulse occurring at the beginning of each variable pulse interval. The successive stages are enabled by the occurrence of a clock pulse of a clock signal selected by the previous stage. The lastmost stage provides an output corresponding to the variable width pulse.

Abstract: An apparatus for electrophotographically manufacturing a luminescent screen assembly on a substrate for use within a CRT includes a developer for developing a photoconductive layer, having a latent image thereon, with a dry-powdered, triboelectrially-charged screen structure materials. The photoconductive layer overlies a conductive layer in contact with the substrate. A grid-developing electrode is located at a distance from the photoconductive layer that is large relative to the smallest dimension of the latent image. The electrode is biased with a suitable potential to influence the deposition of the charged screen structure materials onto the latent image on the photoconductive layer. A method for electrophotographically manufacturing the screen assembly utilizing the grid-developing electrode is also disclosed.

Abstract: An apparatus for uniformly charging a photoconductive layer disposed on an interior, non-planar surface of a faceplate panel of a CRT during electrophotographic screen processing of the panel includes a corona generator having at least one corona charger and a mechanism for moving the corona charger across the non-planar surface of the faceplate panel. The corona charger substantially conforms to, and is spaced from the photoconductive layer on the non-planar, interior surface of the faceplate panel.

Abstract: A method for making a dark, adherent coating on exposed metal surfaces of a color-selection electrode assembly of a CRT includes the steps of applying a first solution of aqueous phosphoric acid to the metal surfaces of the assembly; contacting the metal surfaces with a second solution of selenium dioxide and methanol; rinsing the assembly; and then, applying a sealing solution to the surfaces of the assembly.