Hitachi Maxell, Limited

Kazuko Ishitsuka

Norio Ohta

Katsusuke Shimazaki

Toshinori Sugiyama

Osamu Ishizaki

Masafumi Yoshihiro

Akito Sakemoto

Satoru Ohnuki

On a surface of a transparent substrate,having a preformat pattern,formed thereon are laminated a first recording layer,in which a recording state exists in one different magnetic field region of an applied external magnetic field and a second recording layer,in which two recording states exist in magnetic field regions different from that for the first recording layer. As required, dielectric layers,and,, a reflecting layer,and a protection layer,can be laminated. The 4-valued recording of information becomes possible by assigning information signals &ldquo;1&rdquo;, &ldquo;0&rdquo;, &ldquo;3&rdquo;, and &ldquo;2&rdquo; to H,, H,, H,and H,, respectively.

Magneto-optical recording medium capable of recording multiple value signals

An optomagnetic recording and reproducing system has been developed which demonstrates superior performance when used with multilayer recording substrates. The system features an optical head and magnetic head disposed opposite to each other on different sides of the recording substrate. The novel magnetic head can either incorporate a number of independently driven subheads, or alternately it can be constructed by placing multiple independently driven windings on a single head. Biasing of the magnetic head can either be performed externally using an external magnet or by providing a bias with one of the windings or sub-heads. The resulting optomagnetic recording and reproducing system is suitable for multi-valued recording of an optomagnetic recording medium.

Magnetic head capable of generating multi-stepped external magnetic

Magneto-optical recording medium having a plurality of magnetic layers

Growing community of inventors

Iwai, Japan

Kazuko Ishitsuka