| 摘要 |
PROBLEM TO BE SOLVED: To accurately evaluate an actual quantity of asymmetry of a magnetic head characteristic. SOLUTION: Q bit patterns are composed of a pattern L<SB>1</SB>having a magnetization reversal only in a first bit period of a half cycle of an LF pattern of square waves whose one cycle is 2M bits (M is an integer), and 1T patterns H<SB>1</SB>of 2N bits (N is an integer) and H<SB>2</SB>of 2N+1 bits are arranged in the order of L<SB>1</SB>, H<SB>1</SB>, L<SB>1</SB>, H<SB>1</SB>, L<SB>1</SB>, H<SB>2</SB>. An equation N>>M is met. The values of N are different for each of the Q bit patterns, and repeated one of the Q bit patterns is reproduced. For each of the Q bit patterns, amplitude to an average DC level of a reproduced waveform of positive and negative polarities corresponding to the LF pattern is measured among the reproduced waveforms by a waveform measuring means. An evaluation means receives Q (≥3) sets of measured value from the waveform measuring means, and calculates the actual quantity of asymmetry of the reproduced waveform corresponding to the LF pattern based on the measured values. COPYRIGHT: (C)2009,JPO&INPIT
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