Patents Represented by Attorney T. Carter Pledger
  • Patent number: 4922397
    Abstract: A DC to DC converter is described having a bridge circuit coupled to the secondary windings of a transformer, the transformer supplying power to a capacitor and a constant current load source. The circuit parameters are chosen to provide a circuit that has quasi-resonant characteristics close to the frequency of the signal providing power to the transformer, but at a higher value. Other constraints on the circuit parameters are discussed. The resulting circuit provides an efficient transfer of energy from the source power supply to the load.
    Type: Grant
    Filed: February 6, 1989
    Date of Patent: May 1, 1990
    Assignee: Digital Equipment Corporation
    Inventor: Albert M. Heyman
  • Patent number: 4918526
    Abstract: In order to process video images under control of a data processing system, a video signal processing device is described that can be coupled to a data processing system interface unit. The video signal processing device includes two image frame buffers and apparatus for transferring signals in a controllable manner between the two image frame buffers. The video signal processing device also includes apparatus for combining the output signals of the image frame buffers in a controllable manner. The control of the signal transfer between image frame buffers and the control for the combining of the output signals of the image frame buffers is provided by the data processing system. The data processing system loads a multiplicity of registers with information to provide the desired output signal and the video signal processing unit executes the functions determined by the register contents. In this manner, the data processing system can devote relatively few of the available resources to processing the image.
    Type: Grant
    Filed: March 20, 1987
    Date of Patent: April 17, 1990
    Assignee: Digital Equipment Corporation
    Inventors: Richard E. Lewis, John C. Kingsolver
  • Patent number: 4896315
    Abstract: Apparatus and method are disclosed for determining the location of a network component coupled to a local area network segment. A remote segment monitor unit is coupled to either end of a cable segment of a local area network system. The remote segment monitor unit, for each transaction on the cable segment, determines a value related to the transaction signal strength and determines the identity of the network node from which the transaction originated. By providing a record of the transaction signal strength associated with each network node (component) in both remote segment monitors, the location of network nodes can be ascertained.
    Type: Grant
    Filed: November 23, 1987
    Date of Patent: January 23, 1990
    Assignee: Digital Equipment Corporation
    Inventors: Michael A. Felker, Chang J. Wang, Angelo N. Viverito, John W. Gilstrap, Jesus J. Martos
  • Patent number: 4890278
    Abstract: Apparatus and method are disclosed for providing a calibrated measurement of signals applied to a local area network cable segment. A remote segment monitor unit has the signal sampling circuit coupled to a signal generating unit. The signal generating unit is controlled by a network system member (node) and applies a series of known signal levels to the signal sampling circuit of the remote segment monitor unit. The known signal levels from the signal generating unit and the signal levels measured by the remote segment monitor as a result of the known signal levels are compared and an appropriate scale factor entered in the processing circuit of the remote segment monitor. Using the calibrated remote segment monitor, the location of network nodes can be identified from the signal levels measured by the remote segment monitor.
    Type: Grant
    Filed: June 16, 1989
    Date of Patent: December 26, 1989
    Assignee: Digital Equipment Corporation
    Inventors: Michael A. Felker, Angelo N. Viverito, John W. Gilstrap, Jesus J. Martos, Ruben Trujillo, Chang J. Wang
  • Patent number: 4835599
    Abstract: In order to represent a color image with a reduced quantity of information, during the transformations from color parameter pixel information to luminance/chrominance information, the first of the three luminance/chrominance parameters (i.e., the luminance) is determined for each pixel point. The two remaining luminance/chrominance parameters are determined for a predetermined pixel subarray. The luminance/chrominance subarray parameters are determined by calculating the remaining luminance/chrominance parameters for the pixel array. The remaining luminance/chrominance parameters are then determined for each pixel subarray location by calculating a weighted average of the parameters for the pixel locations that are in the neighborhood of the subarray. Only the averaged luminace/chrominance parameters for the subarray are then stored along with the first luminance/chrominance parameters for all pixels.
    Type: Grant
    Filed: February 25, 1987
    Date of Patent: May 30, 1989
    Assignee: Digital Equipment Corporation
    Inventor: Claude A. Sigel
  • Patent number: 4799211
    Abstract: A remote segment monitor unit is disclosed that is coupled to a segment cable of a local area network system. The remote segment monitor unit, for each transaction on the cable segment, determines a value related to the transaction signal strength and determines the identity of the network node from which the transaction originated. By providing a record of the transaction signal strength associated with each network node as a function of time, components that are functioning outside of acceptable boundaries, components showing erratic behavior and components with deteriorating performance can be identified.
    Type: Grant
    Filed: July 23, 1987
    Date of Patent: January 17, 1989
    Assignee: Digital Equipment Corporation
    Inventors: Michael Felker, Angelo Viverito
  • Patent number: 4749093
    Abstract: A memory aid is provided for use with a vial for containing medicine taken in doses at predetermined times. The aid comprises a base for attachment to a vial, a top, a reminder for moving relative to the top, and a locking element for preventing relative movement between the reminder and the top in one direction and permitting relative movement in the other direction.
    Type: Grant
    Filed: March 11, 1987
    Date of Patent: June 7, 1988
    Inventor: O. Lee Trick
  • Patent number: 4666051
    Abstract: A memory aid is provided for use with a vial for containing medicine taken in doses at predetermined times. The aid comprises an attachment base for attachment to a conventional top for the vial, an attachment top, a reminder for moving relative to the attachment top, and a locking element for preventing relative movement between the reminder and the attachment top in one direction and permitting relative movement in the other direction.
    Type: Grant
    Filed: July 22, 1985
    Date of Patent: May 19, 1987
    Inventor: O. Lee Trick
  • Patent number: D295024
    Type: Grant
    Filed: May 6, 1985
    Date of Patent: April 5, 1988
    Inventor: O. Lee Trick