Nippon Hoso' Kyokai

Matsushita Electric Industrial Co., Ltd.

Fuji Photo Film Company, Limited

Japan Broadcasting Corporation

Hotaka Minaguchi

Toshihiro Uehara

Tatsuji Kitamoto

Koji Sasazawa

Yasunori Kawakami

Mikio Fujiwara

Yoshinobu Oba

Sigekazu Togashi

Hiromichi Shibaya

A digital signal recording/reproducing system specifically has an adaptive automatic equalizer for performing automatic waveform equalization disposed in a reproducing circuit of an RF system. In order to provide a run-up pattern which enables stable operation settlement of the adaptive automatic equalizer and a clock reproducing PLL at the time of reproduction, the digital signal recording/reproducing system comprises a run-up code generator for producing a run-up pattern composed of a combination of at least two digital value series of different inversion intervals. Thus, since an optimum run-up pattern for the reproducing circuit of the RF system is produced and recorded on a recording medium within a fixed period at the time recording, stable settlement of the operation of the clock reproducing PLL and the adaptive automatic equalizer is attained within a run-up period at the time of reproduction, thereby making it possible to suppress occurrence of a code error to a minimum.

Digital signal recording/reproducing system

A digital modulation method for modulating 8-bit digital data into 14-bit digital modulation codes. The number of consecutive identical bits in a series of 14-bit digital modulation codes is restricted to 2-7. The absolute value of DSV at the end of each 14-bit digital modulation code is restricted to 2 or less, and the absolute value of DSV at each bit of any 14-bit digital modulation codes is limited to 7 or less. The direct current component of the 14-bit modulation codes can be effectively reduced.

Digital modulation method

A method for magnetic recording and reproduction comprising the steps of: (1) magnetically multiple-recording signals on a magnetic recording medium comprising a support having thereon an upper magnetic recording layer comprising barium ferrite having an increased coercive force at 60.degree. C. or more and a lower magnetic recording layer comprising at least one of chromium dioxide and Co-modified iron oxide, having a decreased coercive force at 60.degree. C. or more, disposed between said upper magnetic recording layer and said support; (2) heating said magnetic recording layers prior to reproduction due to a reproducing head; and (3) reproducing said magnetically recorded signal from said heated magnetic recording medium which is multiple-recorded.

Magnetic recording medium and method for magnetic recording and

Growing community of inventors

Tokyo, Japan

Hotaka Minaguchi