Patents by Inventor Gerald L. Pressman

Gerald L. Pressman 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: 5485320
    Abstract: In a magnetic recording system, an asymmetry detector reverses the phase of a read, single-frequency test signal to indicate to a micro-controller whether recording signal asymmetry is present. Upon detecting such asymmetry, the micro-controller causes a current source coupled to the recording head to adjust a write current to correct the timing of a written data signal.
    Type: Grant
    Filed: May 24, 1993
    Date of Patent: January 16, 1996
    Assignee: Trace Mountain Products, Inc.
    Inventors: Russell Vogel, William D. Van Alstyne, Gerald L. Pressman, Charles A. Linquist, James L. Michelotti, Paul A. Lind
  • Patent number: 5479098
    Abstract: In a magnetic recording system, a loop-back test circuit provides a technique to test a magnetic recording head, a read circuit, and a write circuit to a read-write head, is sensed through the voltage generated at the head by the test current, such that a small voltage portion of the test signal is transferred through a resistor toga read circuit. The voltage portion is then filtered through a capacitor to form detectable peaks such that the read signal is generated with pulses corresponding to the peaks.
    Type: Grant
    Filed: March 15, 1993
    Date of Patent: December 26, 1995
    Assignee: Trace Mountain Products, Inc.
    Inventors: Ray Y. Yokoyama, Gerald L. Pressman
  • Patent number: 4338614
    Abstract: An improved electrostatic print head is disclosed comprising a corona source, an aperture mask, a slotted focus plane, and a back plane electrode for supporting a moving dielectric print medium. The aperture mask includes two rows of staggered circular apertures which are surrounded by individual aperture electrodes on the side of the mask facing away from the corona source. The side of the aperture mask facing the corona source has a continuous conductive layer thereon which is biased at a fixed potential. The aperture electrodes are selectively pulsed with a control potential to control the flow of ions from the corona source through the two staggered rows of apertures and the slotted focus plane to form any desired dot-matrix latent image on the moving dielectric print medium.
    Type: Grant
    Filed: October 22, 1979
    Date of Patent: July 6, 1982
    Assignee: Markem Corporation
    Inventors: Gerald L. Pressman, Robert A. Moore, Jeffrey B. Brooks, Robert W. Sengstaken, Jr.
  • Patent number: 4318002
    Abstract: The invention basically comprises systems and methods relating to the field of electrostatics and is concerned with multicolor electrostatic reproduction, printing or constituting on coated and uncoated print receiving media with multilayer apertured elements or screens carrying charge distributions in accordance with selected color separation patterns. Ions accelerated through the apertures of the multilayer element pass therethrough under modulation control dictated by the color separation pattern, thereby forming a modulated ion stream having a cross-sectional density pattern corresponding to the color separation pattern. Electrostatic latent images are formed with modulated ion streams and are developed in various ways.
    Type: Grant
    Filed: August 27, 1979
    Date of Patent: March 2, 1982
    Assignee: ElectroPrint, Inc.
    Inventors: Gerald L. Pressman, Kenneth W. Gardiner
  • Patent number: 4181423
    Abstract: The invention basically comprises systems and methods relating to the field of electrostatics and is concerned with multicolor electrostatic reproduction, printing or constituting on coated and uncoated print receiving media with multilayer apertured elements or screens carrying charge distributions in accordance with selected color separation patterns. Ions accelerated through the apertures of the multilayer element pass therethrough under modulation control dictated by the color separation pattern, thereby forming a modulated ion stream having a cross-sectional density pattern corresponding to the color separation pattern. Electrostatic latent images are formed with modulated ion streams and are developed in various ways.
    Type: Grant
    Filed: November 8, 1976
    Date of Patent: January 1, 1980
    Assignee: Electroprint, Inc.
    Inventors: Gerald L. Pressman, Kenneth W. Gardiner
  • Patent number: 4158564
    Abstract: An electrostatic latent image is impressed on a multilayer apertured screen to establish within the apertures electric fields that modulate the passage of charged particles through the screens so that the charged particles are distributed in correspondence with the image. After imaging the screen is operated to control the gray scale response thereof in order to optimize copy quality. The gray scale screen response is expanded by applying a bias voltage of at least two different values to the screen during the duplication interval. The response is limited by altering the latent image charge to provide a high density cutoff and by applying a bias voltage to establish a low density cutoff during the duplication interval. Copy quality is further improved by adjusting the integrated charged particle current to establish the desired degree of density in regions of the copy image corresponding to high density regions of the original image.
    Type: Grant
    Filed: January 3, 1978
    Date of Patent: June 19, 1979
    Assignee: Electroprint, Inc.
    Inventors: Kenneth W. Gardiner, Gerald L. Pressman
  • Patent number: 4103895
    Abstract: A game or test of skill which is comprised of three principal components: a playing surface that either conceals or suggests a secret pattern of paths, a probe for selecting points on the playing surface, and an indicator that reveals whether a selected point belongs on the pattern of paths. In a preferred form of the game the playing surface is a small card on which is marked a grid that indicates the possible positions and orientations of the concealed paths in the pattern. A start point is indicated on the grid; the player places a hand-held pencil-like probe at the start point and tries to find a continuous path from the start point to the end point. The probe leaves no mark on the card, but the player is aided by the indicator which provides a signal when the probe is on-path--the signal ceases abruptly if the probe is moved off-path.
    Type: Grant
    Filed: March 19, 1976
    Date of Patent: August 1, 1978
    Inventors: Gerald L. Pressman, Louis Wilk
  • Patent number: 4082448
    Abstract: A system for controlling the flow of charged particles and for modulated aperture electrostatic printing. An apertured screen having substantially the entire surfaces formed of a dielectric material is charged with like charges over substantially all of its surfaces to develop fringing fields in the apertures. The charge distributed across one side of the screen is selectively dissipated in accordance with the pattern to be reproduced, thereby modifying the fringing fields to form an electrostatic latent image for controlling a flow of charged particles directed to the screen. The screen is initially pre-image charged to carry a higher potential V.sub.A on one face than on the other V.sub.B to provide a potential difference V.sub.A - V.sub.B through the screen apertures.
    Type: Grant
    Filed: November 25, 1974
    Date of Patent: April 4, 1978
    Assignee: ElectroPrint
    Inventor: Gerald L. Pressman
  • Patent number: 4016813
    Abstract: An electrostatic line printing process employing multilayered particle modulator comprising a layer of insulating material on one side of the insulating layer and a segmented layer of conducting material on the other side of the insulating layer. At least one row of apertures is formed through the multilayered particle modulator. Each segment of the segmented layer of conductive material is formed around a portion of an aperture and is insulatively isolated from every other segment of the segmented conductive layer. Selected potentials are applied to each of the segments of the segmented conductive layer while a fixed potential is applied to the continuous conductive layer. An overall applied field projects charged particles through the row of apertures of the particle modulator and the density of the particle stream is modulated according to the pattern of potentials applied to the segments of the segmented conductive layer.
    Type: Grant
    Filed: January 21, 1975
    Date of Patent: April 12, 1977
    Assignee: Electroprint, Inc.
    Inventors: Gerald L. Pressman, John V. Casanova
  • Patent number: 4014694
    Abstract: A machine for making a copy on a medium such as paper of a visual image. Particles of toner material are accelerated toward the paper through an apertured screen. Formed on the screen is a pattern of electrostatic charge regions that corresponds to the image so that the arrangement of the toner particles impinging on the paper corresponds to the image. A composite apertured screen composed of two conductive layers separated by an insulative layer and having an insulative layer on one outer surface. Means for establishing oppositely polarized fields across the inner insulative layer and across the outer insulative layer. One of the fields is selectively discharged to control the passage of toner particles through the apertures in the screen.
    Type: Grant
    Filed: February 18, 1975
    Date of Patent: March 29, 1977
    Assignee: Electroprint, Inc.
    Inventors: Hewitt D. Crane, Gerald L. Pressman, George J. Eilers
  • Patent number: 4006983
    Abstract: The invention basically comprises systems and methods relating to the field of electrostatics and is concerned with multicolor electrostatic reproduction, printing or constituting on coated and uncoated print receiving media with multilayer apertured elements or screens carrying charge distributions in accordance with selected color separation patterns. Ions accelerated through the apertures of the multilayer element pass therethrough under modulation control dictated by the color separation pattern, thereby forming a modulated ion stream having a cross-sectional density pattern corresponding to the color separation pattern. Electrostatic latent images are formed with modulated ion streams and are developed in various ways.
    Type: Grant
    Filed: October 29, 1973
    Date of Patent: February 8, 1977
    Assignee: Electroprint, Inc.
    Inventors: Gerald L. Pressman, Kenneth W. Gardiner
  • Patent number: 3977323
    Abstract: A system for electrostatic printing including a corona source and electrode for coulombs/m.sup.a substantially uniform stream of ions in the direction of a print receiving medium and a multilayer apertured modulator interposed in the ion stream for modulating the cross-sectional flow density of ions in the stream in accordance with a pattern to be reproduced. A cloud of substantially uncharged liquid aerosol ink particles is introduced adjacent the print receiving medium whereby the modulated ion stream selectively impinges upon and charges particles in the cloud which are thereby accelerated and deposited on the print receiving medium in accordance with the pattern to be reproduced. The average surface charge density on liquid aerosol particles in the cloud is no greater than about 1 .times. 10.sup.-.sup.6 coulombs/m.sup.2, and preferably no greater than about 5 .times. 10.sup.-.sup.7 coulombs 2. The liquid aerosol droplets are in the range of from about 0.10 micron to 50.
    Type: Grant
    Filed: June 2, 1975
    Date of Patent: August 31, 1976
    Assignee: ElectroPrint, Inc.
    Inventors: Gerald L. Pressman, David E. Blake, Hugh F. Frohbach
  • Patent number: 3972716
    Abstract: A system for electrostatic photography using a camera having an aperture formed in one side for imaging light onto a photoconductive insulating layer positioned and supported in the camera housing to permit formation of an electrostatic latent image on dielectric film. A contact charging plate including a conductive layer and the photoconductive insulating layer is positioned in the camera so that light passing through the aperture is imaged onto the photoconductive layer. A dielectric camera "film" is positioned adjacent the photoconductive insulating layer and the film and photoconductive layer are pressure biased against each other. A voltage pulse is applied between conductive layers on either side of the dielectric film and photoconductive layer during exposure of the photoconductive layer to an image to establish on the film an electrostatic latent image which is developed with toner marking particles.
    Type: Grant
    Filed: January 24, 1972
    Date of Patent: August 3, 1976
    Assignee: Electroprint, Inc.
    Inventor: Gerald L. Pressman