Patents by Inventor Timothy J. Donovan

Timothy J. Donovan 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: 5900623
    Abstract: An active pixel sensor implemented with CMOS technology that employs a plurality of photocells, each including a photodiode to sense illumination and a separate storage node with a stored charge that is discharged during an integration period by the photocurrent generated by the photodiode. Each photocell includes a switching network that couples the photocurrent to the storage node only during the integration period while ensuring that a relatively constant voltage is maintained across the photodiode during integration and non-integration periods. The transistors in the switching network operate in a forward active subthreshold region, ensuring linear operation and the diode voltage is clamped to a small positive voltage so that the diode is always reverse-biased. A source-follower generates a output signal correlated to the charge on the storage node that is coupled to column output circuitry that samples the signal.
    Type: Grant
    Filed: August 11, 1997
    Date of Patent: May 4, 1999
    Assignee: Chrontel, Inc.
    Inventors: Randy P.L. Tsang, Lawrence Tze-Leung Tse, Timothy J. Donovan, King Cheung Yen
  • Patent number: 5781241
    Abstract: A method and system is disclosed for scaling computer video in the process of scan rate conversion. In the disclosed system and method storage is provided for at least two lines of graphics pixels per video component composing the computer graphics signals and less than a full frame's worth of the graphics pixels. The graphics pixels are stored as they are provided so that the newest graphics pixels or a linear combination of the newest graphics pixels and stored graphics pixels overwrite previously-stored graphics pixels. In a repeating pattern for every M television lines, where M>2, television pixels composing the television video signals are generated from a weighted sum of the stored graphics pixels such that a different precomputed set of weights are used to compute the television pixels for each of the M television lines. The television signals are horizontally and vertically scaled so the graphics image corresponding to the computer graphics signals being converted fits within a television display.
    Type: Grant
    Filed: November 8, 1996
    Date of Patent: July 14, 1998
    Assignee: Chrontel, Inc.
    Inventor: Timothy J. Donovan
  • Patent number: 5138320
    Abstract: A skew code generator for digitally quantizing the width of a pulse. A series connected string of identical voltage controllable delay elements is supplied with the pulse, which is sensed as it passes through each of the delay elements. Output signals are developed in response to the leading edge of the pulse and are latched in response to the trailing edge of the pulse. An encoder generates a binary output from the latched output signals, which is indicative of the width of the pulse.
    Type: Grant
    Filed: November 14, 1990
    Date of Patent: August 11, 1992
    Assignee: Zenith Electronics Corporation
    Inventors: Duc Ngo, Timothy J. Donovan
  • Patent number: 4766483
    Abstract: An automatic color tuning system includes a counter controlled oscillator that is started in the middle of its controllable frequency range. If the counter counts around and no color burst signal is detected, the oscillator is stopped. Whenever the oscillator is sweeping, an automatic phase control circuit is operated at low gain for assuring that the oscillator will be close to the frequency of the color burst signal when lock-up occurs. Whenever the oscillator is stopped, the automatic phase control circuit gain is made high. Once the automatic phase control circuit locks up the oscillator to a color burst signal, a subsequent loss of the color signal does not re-initiate the counter.
    Type: Grant
    Filed: June 2, 1987
    Date of Patent: August 23, 1988
    Assignee: Zenith Electronics Corporation
    Inventors: Timothy J. Donovan, Daniel L. Reneau
  • Patent number: 4581754
    Abstract: A rack of radiographically transparent material for positioning and restraining animals such as dogs and cats during radiographical procedures is shown to include converging load support walls to wedge an animal in either a ventro dorsal or dorso ventral position. The converging walls are truncated and separated to provide space for the dorsal spinous processes and the width of the spline and has sufficient width that the weight of the animal is evenly distributed along its trunk to avoid distortion of its anatomy.
    Type: Grant
    Filed: January 5, 1984
    Date of Patent: April 8, 1986
    Inventor: Timothy J. Donovan