In a recording and reproducing apparatus capable of continuously recording to and reproducing from a plurality of media, the recording and reproducing apparatus includes a recording and reproducing device for recording data to and reproducing it from the medium and a controller for performing...http://www.google.com.hk/patents/US5731923?utm_source=gb-gplus-share專利 US5731923 - Medium recording apparatus and medium reproducing apparatus, and medium recording method and medium reproducing method, and medium used therefor 
