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Apparatus and methods for avoiding loss of closed caption data when using extended data services

  • US 5,543,852 A
  • Filed: 06/24/1994
  • Issued: 08/06/1996
  • Est. Priority Date: 06/02/1994
  • Status: Expired due to Term
First Claim
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1. A method for inserting data into a vertical blanking interval line of video frames, the method comprising the steps of:

  • inserting extended data services (EDS) data into a first vertical blanking interval line in a first field for a plurality of consecutive video frames;

    counting a number of consecutive video frames having EDS data inserted into the first vertical blanking interval line;

    terminating the insertion of EDS data for a first number of video frames before again inserting EDS data into the first vertical blanking interval line when the counted number of consecutive video frames into which EDS data is inserted into the first vertical blanking interval line equals a second number;

    inserting second data into a second vertical blanking interval line in a second field for a plurality of consecutive video frames, the second vertical blanking line being a same line number as a line number for the first vertical blanking line number;

    detecting when the insertion of second data into the second vertical blanking interval line terminates;

    terminating for a second number of video frames the insertion of EDS data into the first vertical blanking interval line upon detecting the termination of insertion of the second data into the second vertical blanking interval line; and

    repeating the steps.

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