摘要 |
There is disclosed a magnetic field generating device for use in a magnetooptical recording apparatus of a magnetic field modulation method. The device includes a planar spiral coil, of which coil pitch is smaller in the peripheral area than that in the central area thereof, thus realizing a relatively wide area of magnetic field of uniform intensity, with a low inductance. Because of the planar structure, the device can be positioned very close to the recording medium, and can achieve the high speed switching required in the magnetic field modulation method, without a large power source.
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