Magnetic recording device, head evaluation device, and write-pole-erasing evaluation method

A head evaluation device, comprising:

• a write controller configured to control,
• a first write operation of writing first information having the same polarity throughout the first information in a first predetermined region comprising a plurality of tracks in a recording medium,
• a second write operation of writing second information in a second region on a target track within or substantially close to the first predetermined region, and
• a third write operation of writing third information in a third region of the target track outside of the second region, the third information having, at an end of the writing, a polarity opposite to the polarity in the first write operation;
• a read controller configured to cause the second information to be read after the second write operation and the third write operation;
• and
• a determination module configured to determine occurrence of pole erasing based on the second information read from the recording medium.

A write-pole-erasing evaluation method, comprising:

• first-writing of writing first information having the same polarity throughout the first information in a first predetermined region comprising a plurality of tracks in a recording medium;
• second-writing of writing second information in a second region on a target track within or substantially close to the first predetermined region;
• third-writing of writing third information in a third region of the target track outside of the second region, the third information having, at an end of the writing, a polarity opposite to the polarity in the first-writing;
• first-reading of reading the second information after the second-writing;
• second-reading of reading the second information after the third-writing;
• and
• determining occurrence of pole erasing based on the second information read in the second-reading and the third-reading.