A video cassette recorder includes a tape transport and servo that records digital data at one tape speed and plays back the digital data at one twentieth of the recording speed, both with a fixed speed of rotation of a drum head. On playback, each recorded segment of data on the tape is read from...http://www.google.de/patents/US5802243?utm_source=gb-gplus-sharePatent US5802243 - Time expansion method and system for slower than real-time playback with video cassette recorders 
