| 摘要 |
PURPOSE:To produce a magnetic field vertical to the film surface of a photomagnetic recording medium in a sharp and intensive way in terms of space, by using >=2 pieces of electromagnets contains magnetic cores set opposite to each other as the external magnetic field generating means and conducting the current to the coils so that the same polarities are set opposite to each other. CONSTITUTION:The coils containing magnetic cores, i.e., the electromagnets 20 and 21 are set opposite to each other as the external magnetic field generating means. Here a gap space between both magnets 20 and 21 is decided so that the luminous flux given from an objective lens 9 can pass through said gap. Then the current is conducted to both coils so that the same polarities of both magnets 20 and 21 are set opposite to each other. As a result, a sharp vertical magnetic field is obtained in terms of space between both electrodes 20 and 21. Thus it is possible to produce a magnetic field vertical to the film surface of a photomagnetic recording medium 10 in a sharp and intensive way in terms of space. |
