Patents by Inventor Shailendra Kumar

Shailendra Kumar 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: 5909231
    Abstract: In a inkjet print cartridge ink flows from the reservoir around the edge of the silicon substrate before being ejected out of the nozzles. During operation, warm thermal boundary layers of ink form adjacent the substrate and dissolved gases in the thermal boundary layer of the ink form the bubbles. If the bubbles to grow larger than the diameter of subsequent ink passageways these bubbles choke the flow of ink to the vaporization chambers. This results in causing some of the nozzles of the printhead to become temporarily inoperable. The disclosure describes a method of avoiding such a malfunction in a liquid inkjet printing system by providing a method for reducing residual air bubbles in an inkjet print cartridge by flushing the empty cartridge by passing carbon dioxide through the fill port or the ink ejection nozzles prior to filling the print cartridge with ink and thereby eliminating residual air bubbles from the print cartridge when the print cartridge is filled with ink.
    Type: Grant
    Filed: October 30, 1995
    Date of Patent: June 1, 1999
    Assignee: Hewlett-Packard Co.
    Inventors: Winthrop D. Childers, Brian J. Keefe, Barbara Parcells, Frank Drogo, Shailendra Kumar, Steven L. Webb, Hanno Ix, Kai Kong Iu
  • Patent number: 5742685
    Abstract: An identification card and method and apparatus for producing and authenticating such an identification card. A person whom the identification card will identify, is scanned to produce a digital signal which is compressed, encrypted, and coded as a two dimensional barcode or as some other appropriate form of coding, which is incorporated into one portion of the identification card. The image is also printed or otherwise embodied onto another portion of the identification card. A text message maybe appended to the signal before it is encrypted and also printed as plain text on the identification card. In one embodiment the signal representing the image is encrypted using a public key encryption system and the key is downloaded from a center. To validate the card the coded message is scanned, decoded, decrypted, expanded and displayed.
    Type: Grant
    Filed: October 11, 1995
    Date of Patent: April 21, 1998
    Assignee: Pitney Bowes Inc.
    Inventors: William Berson, Shailendra Kumar
  • Patent number: 5420924
    Abstract: An identification card and method and apparatus for producing and authenticating such an identification card. An object or other entity for which the identification card will evidence identity, status or characteristics is scanned to produce a digital signal a portion of which is compressed, encrypted, and coded and which is recorded on a magnetic strip on the identification card. The image is also printed or otherwise embodied onto another portion of the identification card. A text message maybe appended to the signal before it is encrypted and also printed as plain text on the identification card. In one embodiment the signal representing the image is encrypted using a public key encryption system and the key is downloaded from a center. This key maybe changed from time to tome to increase security. To facilitate authentication the corresponding decryption key is encrypted with another key and incorporated on the card.
    Type: Grant
    Filed: April 26, 1993
    Date of Patent: May 30, 1995
    Assignee: Pitney Bowes Inc.
    Inventors: William Berson, Shailendra Kumar
  • Patent number: 4651126
    Abstract: An electrical resistor of resistivity of less than about 600 ohms per square and with a temperature coefficient of resistance within the range of .+-.200 ppm/.degree.C. comprises an insulating substrate, electrically conductive terminations on a surface of the substrate, and a layer of resistor material on the surface of the substrate and in contact with the terminations. The resistor material comprises from about 25 to about 35% by weight glass and from about 50% to about 75% by weight conductive particles. Preferably the conductive particles consisting essential of tin oxide and at least about 0.2% by weight of ruthenium containing material, expressed as RuO.sub.2. The mass ratio of ruthenium containing material (as RuO.sub.2) to tin oxide is less than 7:93.
    Type: Grant
    Filed: May 2, 1985
    Date of Patent: March 17, 1987
    Inventors: Shailendra Kumar, Gerald Lorenz, Nellie L. Cabato