LENGTH INFORMATION ACQUISITION METHOD, MANUFACTURING METHOD OF MAGNETIC RECORDING MEDIUM, LENGTH INFORMATION ACQUISITION DEVICE, AND MAGNETIC RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To acquire length information on the length of a prescribed part of a magnetic recording medium without breaking the magnetic recording medium. SOLUTION: When length information on a length L1a (a first length) along the thickness direction of a magnetic disk 1A where projecting part 21 formed regions (recording regions) and recessed part 22 formed regions (non-recording regions) are alternately arranged and regulated is acquired, the length L1a being a length between the surface of a recording layer 14 (a recording material) in a data track pattern region At and the surface of a non-magnetic material 15 (a non-recording material) in the data track pattern region At, measurement processing is performed of measuring a height L2a (a first height) of a difference in level between the surface (the surface of the recording region) of a protective layer 16 in the projecting part 21 formed region and the surface (the surface of the non-recording region) of the protective layer 16 both in the recessed part 22 formed region in a pattern region Ax (a prescribed region) for measurement which is different from the data track pattern region At, and length information is acquired based on reference data for acquiring length information and the height L2a. COPYRIGHT: (C)2009,JPO&INPIT