| 摘要 |
PURPOSE:To increase magnetic field strength on the plane of a magneto-optical recording medium by arranging a thin plate formed by a magnetic material between the magneto-optical recording medium and an optical pickup. CONSTITUTION:The thin plate 8 formed by the magnetic material with high permeability is arranged on a side opposite to an electromagnet 7 sandwiching the magneto-optical recording medium 1, and constitutes a magnetic circuit with the electromagnet 7. The shape of the plate is formed, for example, in a disk shape magnetic plate in which a hole to pass light is opened in its center, and is set at a size so as not to prevent the light from the optical pickup 5 from being emitted, and also, the thickness of the thin plate 8 is decided paying consideration on the operating distance of the objective lens of the optical pickup 5 and the plane quivering of the recording medium 1, and required magnetic field strength can be obtained by the compact electromagnet 7 by the magnetic circuit consisting of the thin plate 8 and the electromagnet 7. |
