JPS5473014A - High density digital magnetic recording system - Google Patents

Abstract

PURPOSE: To reduce the decrease in the phase signal ratio at the recording and increase density by converting the raw data rows including connection parts to units of 5 digits for each 3 bits and recording the same by an NRZI system.

CONSTITUTION: When 3 bits of data rows are applied to a coding circuit 6 via D type FFs 3 thru 5, the circuit 6 converts the 3 bit datas to units of 5 digits through code conversion according to the first group of Table I. In this case, when the fifth digit of the preceding unit is "1", the conversion according to the second group of Table I is accomplished and if all the digits of the preceding unit are "0", the conversion according to the third group is accomplished. Then, the unit becomes 5 digits in which junctions are included and "1" do not continue, which are then passed through a series-parallel shift register 13 and are made to an NRZI recording signal in an NRZI modulating circuit 14. Hence, the density ratio of bit number per minimum magnetization inversion spacing is increased by the 5 digit conversion of the 3 bit data and the reduction on the phase signal ratio of the ratio of the digits "1" may be made slight.

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