Patents by Inventor Virgil J. Hull

Virgil J. Hull 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: 5307188
    Abstract: A liquid crystal display unit is provided which includes a primary, image-defining display and a secondary display, arranged in series with the primary display. The primary and secondary displays have equal numbers of light shutters, similarly sized and located on each display, so that when the corresponding light shutters on the primary and secondary displays are closed, substantially no light passes through the viewing side of the primary display. An opaque mask is formed on the input side of the primary display to define the shape of the image elements to be displayed. This mask covers the edges of the primary display light shutters to define the image elements display. This mask permits the primary and secondary displays to be easily aligned with each other. Color patches can be located on the light input side of the primary display light shutters so that the viewed images are in color. The use of the opaque mask to form the image elements eliminates the need to form precisely shaped color patches.
    Type: Grant
    Filed: February 2, 1993
    Date of Patent: April 26, 1994
    Assignee: Xerox Corporation
    Inventors: Richard B. Dingwall, Lowell W. Knapp, John H. Steele, James S. Celebi, Virgil J. Hull
  • Patent number: 5220442
    Abstract: A liquid crystal display unit is provided which includes a primary, image-defining display and a secondary display, arranged in series with the primary display. The primary and secondary displays have equal numbers of light shutters, similarly sized and located on each display, so that when the primary and secondary displays are placed in series their respective light shutters are also in series. When corresponding light shutters on the primary and secondary displays are closed, substantially no light passes through the displays to the opposite side of the primary display. An opaque mask is formed on the input side of the primary display to define the shape of the image elements to be displayed. This mask covers the edges of the primary display light shutters to define the image elements such that each light shutter on the secondary display is larger in size than its corresponding image element on the primary display. This permits the primary and secondary displays to be easily aligned with each other.
    Type: Grant
    Filed: September 6, 1991
    Date of Patent: June 15, 1993
    Assignee: Xerox Corporation
    Inventors: Richard B. Dingwall, Lowell W. Knapp, John H. Steele, James S. Celebi, Virgil J. Hull
  • Patent number: 5177475
    Abstract: Liquid crystal devices are provided with a DC current blocking layer which improves the lifetime of the liquid crystal device and also permits the use of two-level drivers, thus reducing the complexity of the driving scheme necessary to address the liquid crystal devices. Preferably, the blocking layer is the alignment layer which is made from poly-para-xylylene having a thickness sufficient to act as a DC blocking layer. Additionally, specific driving schemes for driving liquid crystal devices are provided. When the liquid crystal device includes a material which relaxes when no voltage is applied thereto (e.g., a nematic material), the information signal is entirely removed from alternating time frames during which the liquid crystal device is addressed.
    Type: Grant
    Filed: December 19, 1990
    Date of Patent: January 5, 1993
    Assignee: Xerox Corporation
    Inventors: Joseph F. Stephany, Joseph J. Wysocki, Sui K. Hark, Virgil J. Hull
  • Patent number: 5111320
    Abstract: A light shutter is provided wherein a first plate which includes a pixel electrode for use in applying a includes a background electrode located adjacent the pixel voltage potential across a ferroelectric material also electrode and substantially surrounding the pixel electrode, whereby an electronic mask can be created adjacent the pixel electrode in the ferroelectric material. A second plate which, along with the first plate sandwiches the ferroelectric material, includes a backplane electrode which is used in conjunction with the pixel and background electrodes on the first plate for applying voltage potentials across the ferroelectric material.
    Type: Grant
    Filed: November 29, 1990
    Date of Patent: May 5, 1992
    Assignee: Xerox Corporation
    Inventors: Joseph J. Wysocki, Sui K. Hark, Virgil J. Hull, Joseph F. Stephany, Andras I. Lakatos, Ram S. Narang
  • Patent number: 4830468
    Abstract: A linear array of liquid crystal shutters mounted near a photoreceptor surface and arranged transversely to the direction of travel of the photoreceptor surface, an array of multiplexed thin film transistors (TFT's) connected to the array of liquid crystal shutters for electrically driving the shutters and logic means connected to the multiplexed array of thin film resistors selectively pulsing the liquid crystal shutters to selectively expose the photoreceptor surface a line at a time. The system further includes a single backplane and circuit means for producing an electric field between the backplane and electrodes of each of the liquid crystal shutters to prevent passage of light through the shutters and means for selectively de-energizing each of the pairs of electrodes for predetermined time period in response to the receipt of input data signals.
    Type: Grant
    Filed: June 30, 1988
    Date of Patent: May 16, 1989
    Assignee: Xerox Corporation
    Inventors: Joseph F. Stephany, Andras I. Lakatos, Virgil J. Hull, Alain E. Perregaux
  • Patent number: 4783146
    Abstract: A linear array of liquid crystal shutters mounted near a photoreceptor surface and arranged transversely to the direction of travel of the photoreceptor surface, an array of thin film transistors connected to the array of liquid crystal shutters for electrically driving the shutters and logic means connected to the array of thin film transistors selectively pulsing the liquid crystal shutters to selectively expose the photoreceptor surface a line at a time. The system further includes circuit means for producing an electric field between the opposed electrodes of each of the liquid crystal shutters to prevent passage of light through the shutters and means for selectively de-energizing each of the pairs of electrodes for predetermined time period in response to the receipt of input data signals.
    Type: Grant
    Filed: January 20, 1987
    Date of Patent: November 8, 1988
    Assignee: Xerox Corporation
    Inventors: Joseph F. Stephany, Andras I. Lakatos, Virgil J. Hull, Alain E. Perregaux
  • Patent number: 4728972
    Abstract: The invention is a liquid crystal material between horizontal and vertical electrodes. A xerographic drum is placed underneath the electrodes/liquid crystal configuration and an optical system provides light or no light at the intersection of the electrodes to be focused on the xerographic drum. A single line of data is created by printing first the odd elements of the data and then the even elements. First, data is clocked into a shift register coincident with clock pulses. This is the data for the next line to be printed or displayed and not the presently printed or displayed line of odd bits. When the new line has been completely shifted in, a latch pulse transfers the data to latches, a one line parallel in parallel out buffer. Then, on the even half of the cycle, the even bits of data which have been shifted in while the odd dots are being printed, are latched to the drivers.
    Type: Grant
    Filed: June 15, 1987
    Date of Patent: March 1, 1988
    Assignee: Xerox Corporation
    Inventors: Joseph F. Stephany, Virgil J. Hull, Eugene C. Faucz, Alain E. Perregaux