Patents by Inventor James W. Schwartz

James W. Schwartz 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: 4924148
    Abstract: A high brightness panel display (20) includes a plurality of discrete gas discharge cells (24) sealed against a phosphor-carrying front panel section (26) and operable to produce a high brightness display. Gas discharges are ignited and extinguished in selected gas discharge cells (24) to excite or extinguish associated pixels P.sub.m,n that are formed in portions of phosphor strips (35) on the front panel section (26). The gas discharge cells (24) are controlled with electrodes that are common to several cells but driven so that a gas discharge can be ignited or extinguished in one cell without effecting any other cell. Consequently, the pixels may have a 100% per-frame duty cycle, thereby producing very high brightness.
    Type: Grant
    Filed: June 24, 1988
    Date of Patent: May 8, 1990
    Assignee: Tektronix, Inc.
    Inventor: James W. Schwartz
  • Patent number: 4491872
    Abstract: An ultra-compact projection television receiver is disclosed comprising cabinet means for enclosing the components of the receiver. The receiver has vertically arranged elevatable rear projection screen means selectively storable in the receiver. Means are included for elevating the screen means from a first receiver-inoperable position wherein the screen means is stored in the cabinet and the receiver is substantially as compact as a conventional large-screen console television receiver. In a second, elevated receiver-operable position, the screen means is emerged from the cabinet and is capable of displaying an image with an area greater than three times the image area on a conventional console television receiver.
    Type: Grant
    Filed: January 17, 1983
    Date of Patent: January 1, 1985
    Assignee: Zenith Electronics Corporation
    Inventors: Melvin H. Boldt, James W. Schwartz
  • Patent number: 4326762
    Abstract: Apparatus and method is disclosed for spot-knocking a cathode ray picture tube by beneficial arcing between selected electrodes of an electron gun sealed in the evacuated envelope of the tube. The invention is particularly useful in spot-knocking certain cathode ray picture tubes having a resistive arc-suppression means and static elimination system. The picture tube has an inherent capacitance that can store energy in an amount capable of inducing destructive arcing during spot-knocking. In one embodiment of the invention, a bipolar potential is applied across the electrodes to be spot-knocked, resulting in the amount of energy in the induced arcing, for a given applied potential, being very much less than would be the case if a unipolar potential were applied. Other embodiments include resistive means and spark gap means for discharging the voltage between lead-in pins before a destructive arc can occur therebetween.
    Type: Grant
    Filed: October 15, 1980
    Date of Patent: April 27, 1982
    Assignee: Zenith Radio Corporation
    Inventors: Richard L. Hockenbrock, James W. Schwartz
  • Patent number: 4217521
    Abstract: This disclosure depicts a television picture tube subject to an undesired build-up of localized high-potential static charges and high-potential charge retention. The tube is characterized by a resistive coating deposited on at least one of the normally uncoated outer areas of the tube and in contact with the conductive coating to disperse any static charges by means of a flow of electrons through the resistive coating. The "rush" of electrons which may cause an annoying crackling sound upon tube turn-on and turn-off is attenuated thereby to suppress the sound, and any residual high-potential charges remaining after turn-off are discharged to ground.
    Type: Grant
    Filed: December 21, 1977
    Date of Patent: August 12, 1980
    Assignee: Zenith Radio Corporation
    Inventors: Leonard Dietch, James W. Schwartz
  • Patent number: 4208610
    Abstract: This disclosure depicts a television cathode ray picture tube having a plural-beam electron gun for projecting in superimposition on the picture imaging screen of the tube at least two electron beam spots. The gun includes at least one aperture electrode having an aperture for passage therethrough of each of said beams. The beams are subject to a first-order aberration attributable to the aperture electrode resulting in the astigmatizing, and consequent distortion of, the beam spots. This astigmatizing is due to the coalescing of electric field vectors contiguous to each aperture with the vectors of at least one adjacent aperture. The improvement comprises shielding means interposed between the apertures comprising wall means. The wall means are effective to mutually shield the apertures and isolate the electric field vectors to ameliorate the first order aberration.
    Type: Grant
    Filed: June 9, 1978
    Date of Patent: June 17, 1980
    Assignee: Zenith Radio Corporation
    Inventor: James W. Schwartz
  • Patent number: 4196446
    Abstract: A color television receiver system has a cathode ray picture tube including an imaging faceplate having deposits of multi-color phosphor targets thereon. The tube includes a three-beam electron gun and a color selection aperture mask having apertures in registration with the targets. A beam-current-control signal is derived from the scansion circuit means of the receiver system; the amplitude of the signal varies monotonically as a function of the distance of the beams from the center of the faceplate. Means are provided for receiving the beam-current-control signal for modulating the receiver system luminance signal with the beam-current-control signal, which has such characteristics that the modulation causes a predetermined gradational reduction in beam current as a function of the distance of the beam from the center of the faceplate. The benefits include enhanced color purity and improved resolution, and energy savings.
    Type: Grant
    Filed: November 24, 1978
    Date of Patent: April 1, 1980
    Assignee: Zenith Radio Corporation
    Inventors: William A. Rowe, James W. Schwartz
  • Patent number: 4168452
    Abstract: This disclosure depicts an electron gun especially for use in a color cathode ray tube of the small-neck, shadow-mask type. The gun design is also applicable to other television cathode ray tube displays that require a gun that provides small, symmetrical spots of uniform cross-section, such as guns used in monochrome television and beam index tubes. The gun is comprised essentially of a four-element tetrode section and a main focus lens section. The tetrode section generates at least one electron beam and a cross-over that is imaged on the screen of the tube focused by the main focus lens. The tetrode section is characterized by having a strong prefocus; that is, a prefocus in which the electron trajectories are substantially refracted, or bent, before exiting the tetrode section.
    Type: Grant
    Filed: December 15, 1977
    Date of Patent: September 18, 1979
    Assignee: Zenith Radio Corporation
    Inventors: John A. Christensen, Peter E. Loeffler, James W. Schwartz
  • Patent number: 4158157
    Abstract: This disclosure depicts an image display panel partitioned into two distinct sections comprising a high voltage front section and a low voltage rear section. An electron source means located in the low-voltage rear section is disposed along a row-wise edge of the panel for generating a supply of electrons. A plurality of low-energy electron beams drawn from the electron source means are formed, shaped and modulated. Each beam is directed into a beam guide-isolator responsive to relatively low applied beam control voltages. The beams are further directed by the plurality of beam guide-isolators perpendicular to said edge and parallel to the image display panel faceplate, and are repetitively, and preferably substantially periodically, focused and refocused to constrain the electrons from leaving the beam guide-isolators.
    Type: Grant
    Filed: October 26, 1976
    Date of Patent: June 12, 1979
    Assignee: Zenith Radio Corporation
    Inventor: James W. Schwartz
  • Patent number: 4143298
    Abstract: An improved internal voltage divider for use in a television cathode ray tube is disclosed that provides one or more temperature-invariant voltages. The tube is subject to internal spatial temperature patterns fixed or varying with time which are incidental to tube warm-up and operation. The voltage divider according to the invention is comprised of at least two electrically series connected resistive sections having like temperature coefficients, and having resistive values of the same order of magnitude. Each section is so positioned and arranged relative to the aforesaid temperature patterns as to have similar average temperature experiences. The voltage divider is connected between a relatively high anode voltage and a suitable low-voltage terminal for receiving a relatively low voltage through the base of the tube. Means are provided for tapping off at least one temperature-invariant intermediate voltage.
    Type: Grant
    Filed: September 1, 1977
    Date of Patent: March 6, 1979
    Assignee: Zenith Radio Corporation
    Inventors: Valentijn B. Bing, James W. Schwartz
  • Patent number: 4137486
    Abstract: This disclosure depicts an image display panel partitioned into two distinct sections comprising a high voltage front section and a low voltage rear section. An electron source means located in the low-voltage rear section is disposed along a row-wise edge of the panel for generating a supply of electrons. A plurality of low-energy electron beams drawn from the electron source means are formed, shaped and modulated. Each beam is directed into a beam guide-isolator responsive to relatively low applied beam control voltages. The beams are further directed by the plurality of beam guide-isolators perpendicular to said edge and parallel to the image display panel faceplate, and are repetitively, and preferably substantially periodically, focused and refocused to constrain the electrons from leaving the beam guide-isolators.
    Type: Grant
    Filed: April 25, 1978
    Date of Patent: January 30, 1979
    Assignee: Zenith Radio Corporation
    Inventor: James W. Schwartz
  • Patent number: 4101803
    Abstract: This disclosure depicts a television cathode ray tube including an evacuated glass envelope having on an external surface of a funnel portion thereof an outer conductive coating and on an internal surface thereof an inner conductive coating for receiving a high voltage charge. The tube has an electron gun located in a neck of the funnel.
    Type: Grant
    Filed: June 1, 1977
    Date of Patent: July 18, 1978
    Assignee: Zenith Radio Corporation
    Inventors: Michael Walter Retsky, James W. Schwartz
  • Patent number: 4095138
    Abstract: Arc-inhibiting means for a television picture tube having an electron gun with a main focus lens section of the extended field type. The lens establishes an extended, axially continuously active focusing field which is substantially shielded from external field disturbances. There exist widely disparate potentials with a potential difference in the range of tens of kilovolts across the gap between a grid means of an electron source means and an initial end electrode of the main focus lens. The potential difference is sufficient to introduce a tendency toward destructive arcing between the grid means and the initial end electrode. The electron gun according to the invention is characterized by having at least one arc-inhibiting electrode disposed between the grid means and the initial end electrode, and having a potential thereon that is intermediate to the disparate potentials to provide an arc-inhibiting voltage gradient between the grid means and the initial end electrode.
    Type: Grant
    Filed: November 29, 1976
    Date of Patent: June 13, 1978
    Assignee: Zenith Radio Corporation
    Inventor: James W. Schwartz
  • Patent number: 4069567
    Abstract: This disclosure depicts a method useful in the manufacture of a color cathode ray tube of the type having a phosphor screen and spaced therefrom a tensed color selection electrode. The method is a method of installing the electrode such that under normal tube operating conditions, the electrode is held by a holder in a hypertensed state and is thus capable of withstanding an unusually high electron beam bombardment before relaxing. In a preferred execution the method comprises selecting for the electrode a material which has a significantly higher coefficient of thermal expansion than that of the holder. The electrode and the holder are externally heated together, as by an oven, while the electrode is tensed.
    Type: Grant
    Filed: February 28, 1977
    Date of Patent: January 24, 1978
    Assignee: Zenith Radio Corporation
    Inventor: James W. Schwartz
  • Patent number: 4058753
    Abstract: This disclosure depicts an electron gun for use in a color cathode ray tube of the small neck, shadow mask-type. The gun includes an extended field lens for generating a cluster of electron beams converged and individually focused at the screen of the tube. Three main focus lens means are situated on lens axes which are mutually parallel and parallel to a gun central axis. At least two of the lens axis are off-axis with respect to the gun axis. The focus lens means has for each beam at least three electrodes including a focus electrode for receiving a variable potential for electrically adjusting the focus of the beam. In succession down-beam, there are at least two associated electrodes having potentials thereon which forms in the gaps between adjacent electrodes significant main focus field components. To adjust beam focus, the strength of a first of these components is controlled by adjustment of the voltage received by the focus electrode.
    Type: Grant
    Filed: March 15, 1976
    Date of Patent: November 15, 1977
    Assignee: Zenith Radio Corporation
    Inventors: Allen P. Blacker, James W. Schwartz
  • Patent number: 4032811
    Abstract: This disclosure depicts and describes a unitized, in-line electron gun for television cathode ray tubes having a bead-type structure for mechanically supporting, spacing, and aligning gun components. This disclosure is particularly directed to an improved structure which promotes a greater stability of electrode support with a reduced tendency toward bead fracture.
    Type: Grant
    Filed: December 18, 1975
    Date of Patent: June 28, 1977
    Assignee: Zenith Radio Corporation
    Inventors: James W. Schwartz, Norman F. Gioia, Franklyn P. Gautier
  • Patent number: 4010988
    Abstract: A towel apparatus which handles an endless towel within a cabinet and subjects the same to cleaning and drawing, making use of a low vapor pressure chemical type solvent.
    Type: Grant
    Filed: March 7, 1975
    Date of Patent: March 8, 1977
    Inventor: James W. Schwartz
  • Patent number: 3995194
    Abstract: A television cathode ray tube has associated therewith a power supply for developing discrete supply voltages. A general purpose electron gun is depicted for receiving supply voltages from the power supply to produce a sharply focused beam of electrons at the cathode ray tube screen. The gun comprises associated cathode means and grid means for producing a beam of electrons, and novel focus lens means. The focus lens means receives electrons from the cathode means and a predetermined pattern of voltages from the power supply and comprises at least three electrodes for establishing a single, continuous electrostatic focusing field characterized by having an axial potential distribution which, at all times during tube operation, decreases smoothly and monotonically from a relatively intermediate potential to a relatively low potential spatially located at a lens intermediate position, and then increases smoothly, directly and monotonically from said relatively low potential to a relatively high potential.
    Type: Grant
    Filed: August 2, 1974
    Date of Patent: November 30, 1976
    Assignee: Zenith Radio Corporation
    Inventors: Allen Palmer Blacker, Jr., James W. Schwartz
  • Patent number: 3980819
    Abstract: Method and apparatus for enhancing the edges of video images displayed on a cathode ray tube. The scanning velocity of the cathode ray tube electron beam is modulated so as to counteract the blurring effect which occurs when a video amplitude transition causes an increase in beam current and a corresponding increase in the size of the electron beam spot at the screen of the cathode ray tube. When such a transition occurs, the beam is deflected in the direction of normal scan at a rate which corresponds to the rate of change in the size of the diameter of the spot so as to substantially arrest the spot edge, thereby causing a displayed video transition to have a better defined vertical edge. Horizontal edges of images are sharpened by auxiliary vertical deflection of the electron beam. Image edges are further improved by a video peaking scheme which eliminates the large spot size growth usually associated with large amplitude video transitions which have been peaked.
    Type: Grant
    Filed: November 1, 1974
    Date of Patent: September 14, 1976
    Assignee: Zenith Radio Corporation
    Inventor: James W. Schwartz