Patents by Inventor Charles J. Prazak, III

Charles J. Prazak, III has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5127866
    Abstract: Method and apparatus are disclosed for tensioning uniform foil shadow masks by clamping the edges of a mask and moving the clamps through a preselected fixed displacement, thereby obviating the need for extensive controls on the tensioning process.
    Type: Grant
    Filed: October 29, 1990
    Date of Patent: July 7, 1992
    Assignee: Zenith Electronics Corporation
    Inventors: Robert Adler, Charles J. Prazak, III, Johann Steiner
  • Patent number: 4998901
    Abstract: A method is disclosed for use in the manufacture of a color cathode ray tube having a foil tension mask with a central pattern of apertures. A transparent flat front panel has a cathodoluminescent screen pattern on its inner surface. A plurality of mask support means, located on opposed sides of the screen pattern, have respective mask-receiving surfaces for receiving a shadow mask in tension. Q-height error data is developed according to the invention, and the aperture pattern of the mask in expanded and positioned in response to the error data to compensate for errors in Q-height to bring the mask apertures into registry with the screen pattern. Apparatus for measuring Q-height is also disclosed.
    Type: Grant
    Filed: September 8, 1989
    Date of Patent: March 12, 1991
    Assignee: Zenith Electronics Corporation
    Inventors: Robert Adler, James R. Fendley, Howard G. Lange, Charles J. Prazak, III, Johann Steiner, Paul Strauss
  • Patent number: 4902257
    Abstract: This disclosure describes method and apparatus useful in the manufacture of shadow mask color cathode ray tubes of the flat tension mask type, wherein the shadow masks and associated glass front panels are respectively interchangeable during mask-panel assembly.
    Type: Grant
    Filed: July 22, 1988
    Date of Patent: February 20, 1990
    Assignee: Zenith Electronics Corporation
    Inventors: Robert Adler, James R. Fendley, Howard G. Lange, Charles J. Prazak, III, Johan Steiner, Paul Strauss
  • Patent number: 4891110
    Abstract: An improved cataphoretic process is disclosed for use in the manufacture of a color cathode ray tube. The process provides for depositing in sequence on the tube screening surface at least two separate patterns of phosphor elements, with each pattern of elements capable of emitting light of a different color when excited. The process according to the invention comprises first depositing an electrically conductive coating over the screening surface for use as an electrode during each deposition operation. Second, an electrically insulative barrier is deposited over the conductive coating. Portions of the barrier are removed selectively and sequentially for controlling patterned, sequenced cataphoretic access to the electrically conductive coating.
    Type: Grant
    Filed: November 10, 1986
    Date of Patent: January 2, 1990
    Assignee: Zenith Electronics Corporation
    Inventors: Philomena C. Libman, Charles J. Prazak, III
  • Patent number: 4884006
    Abstract: Inner specular reflection is suppressed in a flat faceplate for use in a color cathode ray tube (CRT) by forming a flat glass faceplate to have an aft, or inner surface characterized by an undefined roughness. By allowing for an aft surface of undefined roughness, a subsequent lapping process is utilized to produce a predetermined roughness of the aft surface that will substantially eliminate specular reflection from that surface.
    Type: Grant
    Filed: December 30, 1986
    Date of Patent: November 28, 1989
    Assignee: Zenith Electronics Corporation
    Inventor: Charles J. Prazak, III
  • Patent number: 4794299
    Abstract: A planar tension mask is disclosed for use in a color cathode ray tube having a substantially flat faceplate. The shadow mask according to the invention has an aperture pattern characterized by the vertical pitch of the apertures being constant, but with the horizontal pitch of the apetures increasing outwardly from the mask center according to a function which is parabolic with horizontal displacement, and parabolic with vertical displacement. The horizontal pitch increase is isotropic in the sense that the increase in pitch is the sum of the horizontal displacement increase and the vertical displacement increase. A color cathode ray tube front assembly having such a shadow mask is also disclosed.
    Type: Grant
    Filed: March 25, 1986
    Date of Patent: December 27, 1988
    Assignee: Zenith Electronics Corporation
    Inventors: Wayne R. Chiodi, Charles J. Prazak, III
  • Patent number: 4767962
    Abstract: A shadow mask blank is disclosed for use in the manufacture of an ultra-high resolution color cathode tube. The mask blank is adapted to be expanded and secured under tension in spaced adjacency to the screen of the tube. The blank comprises a central field of electron-beam-passing apertures, an outer band adapted to be gripped during the expanding, and at least one field of selectively weakened metal between the central field and the outer band. The selectively weakened metal is effective to equalize stress and prevent wrinkling of the blank under electron beam heating when the blank is expanded and secured under tension. An inner band peripheral to the central field may be provided for mounting the blank on a support structure and securing it thereto. Means may also be provided for linking the inner band with the outer band to selectively strengthen weakened areas.
    Type: Grant
    Filed: July 2, 1986
    Date of Patent: August 30, 1988
    Assignee: Zenith Electronics Corporation
    Inventors: Robert Adler, Charles J. Prazak, III
  • Patent number: 4678447
    Abstract: An assembly-in-process consisting of three components-in-process is disclosed. The components-in-process comprise, respectively, a faceplate with a sealing area circumscribing a target area including of plurality of first registration-affording V-grooves; secondly, a shadow mask support assembly having a frame ultimately constituting a part of the tube envelope, and a sealing area having a like plurality of registration-affording V-grooves in alignment with the first V-grooves; and third, a like plurality of balls disposed between the mated first and second V-grooves for establishing precise registration between the faceplate and the frame in the process of screening a pattern of phosphor deposits on the target area and later in the final assembly of the tube.
    Type: Grant
    Filed: June 10, 1985
    Date of Patent: July 7, 1987
    Assignee: Zenith Electronics Corporation
    Inventor: Charles J. Prazak, III
  • Patent number: 4672260
    Abstract: A glass faceplate for use in a color cathode ray tube has a target area with a pattern of phosphor deposits circumscribed by a sealing area, and a frame supporting a shadow mask with a sealing area geometrically matching the sealing area of the faceplate. Three indexing means are spaced apart along the sealing areas for indexing the faceplate in relation to the frame, providing a gap of predetermined width, and leaving at least one corner of the faceplate unsupported. Shims means having shimming dimension equivalent to or slightly less than the predetermined gap width is located in the gap at the unsupported corner, whereby the unsupported corner is supported by the shim means such that the predetermined gap width is maintained during tube fabrication even at the unsupported corner. A method for assembling a color cathode ray tube which utilizes the shimming means according to the invention is also disclosed.
    Type: Grant
    Filed: July 12, 1985
    Date of Patent: June 9, 1987
    Assignee: Zenith Electronics Corporation
    Inventor: Charles J. Prazak, III
  • Patent number: 4652791
    Abstract: A color cathode ray tube comprises an envelope including a faceplate portion having on an inner surface a pattern of cathodoluminescent phosphors deposited thereon. The envelope includes a continuous peripheral support surface within the envelope spaced approximately a predetermined distance from the inner surface of the faceplate. The tube has a tensed foil aperture mask cemented to the support surface by cement means. The mask blank has a first field of apertures in coordinate relationship to the pattern of cathodoluminescent phosphors for color selection. A second field of apertures peripheral to the first field, and coordinate with the support surface, provides for receiving cementing means during assembly of the blank into a cathode ray tube. The apertures have the form of a band of substantially uniform width at least along the sides of the blank, and are small in diameter relative to the width of the band.
    Type: Grant
    Filed: April 30, 1985
    Date of Patent: March 24, 1987
    Assignee: Zenith Electronics Corporation
    Inventors: Kazimir Palac, Charles J. Prazak, III, Paul Strauss
  • Patent number: 4052519
    Abstract: This disclosure depicts a non-settling process for forming on an inner viewing surface of a color cathode ray tube faceplate, a coating of an aqueous slurry composed of an organic binder and a suspension of particulate phosphor material of distributed particle size, which coating exhibits an extraordinarily suppressed radial streaking, a high degree of coating weight uniformity, and a predictable particle size distribution.
    Type: Grant
    Filed: July 2, 1975
    Date of Patent: October 4, 1977
    Assignee: Zenith Radio Corporation
    Inventor: Charles J. Prazak, III
  • Patent number: 3993516
    Abstract: A method of forming a pattern of electron-transmissive apertures in a color selection mask for a color cathode ray tube. The method includes providing an electrically conductive preformed blank comprising a relatively thin aperture-defining layer on a relatively thick substrate layer; establishing a first etchant-resistant structure on the aperture-defining layer; etching through the blank to form preliminary sized and shaped apertures in the aperture-defining layer; establishing a second etchant-resistant structure on the aperture-defining layer; etching the aperture-defining layer forming ultimate apertures in the aperture-defining layer; and stripping the etchant-resistant structure from the aperture-defining layer.
    Type: Grant
    Filed: October 7, 1974
    Date of Patent: November 23, 1976
    Assignee: Zenith Radio Corporation
    Inventors: Charles J. Prazak,III, Raymond M. Stachniak
  • Patent number: 3984902
    Abstract: This disclosure depicts curtain coating apparatus for applying a coating of phosphor or other CRT screen material to the concave inside surface of a curved skirtless cathode ray tube front panel. The apparatus conveys the panel through a curtain of the coating material with its concave surface facing upwardly. The path along which the panel is conveyed (and thus the panel motion) is such as to produce a high degree of uniformity in the coating received by the panel.
    Type: Grant
    Filed: January 5, 1976
    Date of Patent: October 12, 1976
    Assignee: Zenith Radio Corporation
    Inventor: Charles J. Prazak, III