| 摘要 |
The electromagnetic coil for applying a magnetic bias field on the recording bit of a magneto-optical recording disk apparatus is provided with a yoke made of soft magnetic material, such as soft iron. The yoke surrounds the coil's outer round side as well as the coil's flat side remote from the disk side. The light beam or the optical system is arranged in an opening on the yoke on the coil's flat side. The yoke reduces the magnetic resistance of the coil, thus increases the magnetic field intensity at the recording bit which requires a magnetic field intensity over a certain level. Consequently, the required magnetic field intensity is achieved with less coil current, in other words, within a reasonable range of the coil's temperature rise. |
