JPS6448209A - Perpendicular recording and reproducing circuit - Google Patents

Abstract

PURPOSE:To prevent a reading error by a bit shift and to improve a recording density with simple constitution by providing differentiating circuits which differentiate a head reading signal twice and comparator circuits which compare the output signals of the differentiating circuits with a reference level and produce outputs. CONSTITUTION:This recording and reproducing circuit has the differentiating circuits 40, 42 which differentiate twice the head reading signal obtd. by reading of the information recorded on a perpendicular magnetic recording medium by a ring type head 20 and the comparator circuits 44, 48 which compare the output signals thereof with the reference level and produce the outputs. The oscillation of a low frequency by a pattern effect is removed by the 1st differentiation according to this constitution. The reproduction signal corresponding to the rise and fall of the recording signal is not obtainable even if the differentiated output of the 1st time is compared with the reference level and, therefore, this output is further differentiated and is returned to the original signal waveform which is then compared with the reference level to obtain the reproduction signal decreased in the bit shift. The reading error by the bit shift is thus prevented and the high-density recording is enabled by the simple constitution.