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Video telephone system

  • US 5,347,305 A
  • Filed: 12/17/1990
  • Issued: 09/13/1994
  • Est. Priority Date: 02/21/1990
  • Status: Expired due to Fees
First Claim
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1. A method for transmitting and receiving video and audio signals over an ordinary telephone line in substantially real time, comprising:

  • generating at a transmitting station a video signal having video information, said generating step including providing first means having a number of pixels together comprising a frame and wherein said video signal is generated using a number of frames with an updating of frames being provided at a rate of about 7.5 frames per second;

    generating at said transmitting station an audio signal having audio information;

    producing a composite video/audio signal wherein said composite signal includes a mixture of compressed video information and compressed audio information, with said video and audio information being provided to form said composite signal in a manner that permits accurate restoration thereof at a receiver station and proper synchronization of said video information and said audio information, said step of producing including compressing said video information and separately compressing said audio information;

    modulating said composite signal;

    transmitting said modulating composite signal using an ordinary telephone line having a limited band width;

    receiving said modulated composite signal at a receiving station after having been sent over the ordinary telephone line;

    demodulating said modulated composite signal; and

    reproducing said video information and said audio information at the receiving station using said composite signal.

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