Apparatus and methods are provided for inserting data into a vertical blanking interval (VBI) line of video frames. The method includes the steps of inserting first data into a first vertical blanking interval VBI line for a plurality of consecutive video frames, inserting second data into a second vertical...http://www.google.com.tw/patents/US5543852?utm_source=gb-gplus-share專利 US5543852 - Apparatus and methods for avoiding loss of closed caption data when using extended data services
