Patent ID: 7623311
Filing Date: 2009-11-24
Classification: G11B

Abstract:
1. A recording and reproducing apparatus comprising: a magnetic recording medium comprising recording tracks extended on a surface of the substrate so as to lie adjacent to one another, magnetic recording regions formed in each of the recording tracks and having a magnetic recording layer which enables information to be magnetically recorded, and magnetic missing portions which are formed in each of the recording tracks so as to separate the magnetic recording regions from one another, no information being magnetically recorded in the magnetic missing portions; an acquiring section which acquires position identifying information enabling positions of the magnetic missing portions to be identified; a recording and reproducing section which records information in a recording layer in the magnetic recording medium and which reproduces information from the recording layer; and an authenticating section which extracts the positions of the missing portions from the information reproduced by the recording and reproducing section and which compares the extracted missing positions with the position identifying information to authenticate the magnetic recording medium.