Patents by Inventor David R. Ahlgren

David R. Ahlgren 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).

  • Hybrid lesson format
    Patent number: 6293802
    Abstract: A hybrid format for representing a video lesson which is transported from a first location to a second location across a communication channel includes a first item having a first format type and a second item having a second format type. The first format type is different from said second format type, yet the lesson can be played to the student as if it were a single contiguous data item. As such, efficiencies can be obtained in storage and transfer.
    Type: Grant
    Filed: January 29, 1998
    Date of Patent: September 25, 2001
    Assignee: Astar, Inc.
    Inventor: David R. Ahlgren