Patents by Inventor Leonard H. Greenberg

Leonard H. Greenberg 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).

  • Apparatus for telephone communication over plural channels
    Patent number: 6091721
    Abstract: A method and apparatus for facilitating voice and data communication between audio communication devices while utilizing a communication path other than long distance telephone lines includes interface adapters which respond to predetermined identification codes to automatically establish the desired communication path.
    Type: Grant
    Filed: February 28, 1997
    Date of Patent: July 18, 2000
    Inventors: Leonard H. Greenberg, Philip L. Young
  • Method and apparatus for generating a video signal producing an unviewable display from a videotape recording thereof
    Patent number: 5589944
    Abstract: A standard video signal is modified such that the modified video can be displayed in a normal fashion on a standard monitor device, yet copies made of the modified video signal by videotape recorders will reproduce a video signal containing disturbances which cause a generally unviewable display on a standard television or other video monitor device. The video signal is converted from a standard frame rate to a predetermined, non-standard frame rate video signal utilizing a videotape recorder modified to record at a non-standard speed.
    Type: Grant
    Filed: November 2, 1994
    Date of Patent: December 31, 1996
    Inventors: Philip L. Young, Leonard H. Greenberg
  • Method and apparatus for modifying a video signal to inhibit unauthorized videotape recording and subsequent reproduction thereof
    Patent number: 5251041
    Abstract: A method and an apparatus which modifies a video signal such that a conventional video monitor reproduces a normal picture from the modified video signal, whereas a videotape recording of the modified video signal and subsequent playback thereof produces disturbances in the displayed picture. Predetermined portions of the video signal are identified and copy protection signals are added thereto. The signal mixing and delaying characteristics of a videotape recorder comb filter are exploited to modify, produce and relocate synchronization and burst interfering copy protection signals added to an original videotape recording.
    Type: Grant
    Filed: June 21, 1991
    Date of Patent: October 5, 1993
    Inventors: Philip L. Young, Leonard H. Greenberg