Apparatus for perpendicular magnetic recording on a moving magnetic medium

Abstract

Abstract Apparatus for perpendicular magnetic recording on a moving magnetic medium (14) is designed to provide a low reluctance return path for the magnetic recording flux. The recording head comprises a core (10) of magnetic material carrying a coil (W1), the core having a narrow recording limb (11),and a flux return limb (12) having a much greater cross sectional area. A return path for the magnetic flux is provided on the other side of the magnetic medium (14) and this may comprise either a similar head (10') or a high permeability substrate on which the medium is deposited. The magnetic medium (14) moves in such a direction that it passes first under the flux return limb (12) and then underthe recording limb (11). For reading the recorded information a sub-core (16) carrying a winding (W3) is attached to the flux return limb (12) and is separated by a gap from the tip of the recording limb (15) so as to form with the core a ring-type reading head. This is rendered inoperative during recording by supplying to the winding (W3) a sufficient current to saturate the sub-core. An alternative method of reading employs magneto-resistive elements within the space between the recording limb (11) and the flux return limb (12) arranged to sense flux variations from the recording medium (14).

Inventors

• 👤 Chao Shu Chi

Bibliographic Details