Matsushita Electric Industrial Co., Ltd.

Kousou Takeuchi

Yasuharu Shimeki

Hiroshi Matsushima

Misao Kato

A digital data recording and reproducing method in which a digital data sequence is divided into 8-bit digital data sequences. When the divided 8-bit digital data sequences are encoded into 14-bit code, an 8-bit digital data sequence wherein the value of its DSV (digital sum variation) is limited to a predetermined range is selected from two codes which are assigned to correspond to the 8-bit digital data sequence. In the encoding process, the number of '0' bits which are inserted between two '1' bits in the code sequence is restricted to a number of from one to eight so that the DC component in the code sequence can be eliminated. A bit sequence which never arises in two successive 14-bit code words may then be used as a frame synchronizing signal.

Digital data recording and reproducing method

A method of encoding and decoding binary data, comprising the steps of: dividing the binary data into 2-bit data groups, converting each 2-bit data group into a 5-bit code having a minimum of 4 consecutive bits '0' between a bit '1' and the next bit '1', and converting reversely the encoded 5-bit codes into the original binary data with reference to another 5-bit codes located forwardly of and rearwardly of the 5-bit code. By employing this method, it becomes possible to obtain a density twice higher than that of 'MFM' method.

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Hirakata, Japan

Kousou Takeuchi