| 摘要 |
<p>The electromagnetic coil (5) for applying a magnetic bias field (8) to the recording bit (1-1) of a magnetooptical recording disk apparatus is provided with a yoke (7) made of soft magnetic material, such as soft iron. The yoke (7) surrounds the coil's (5) outer round side (51) as well as the coil's flat side (52) opposite from the disk (1) side. The light beam (21) or the optical system is arranged in an opening of the yoke (7) on the coil's (5) flat side (52). The yoke (7) reduces the magnetic resistance of the coil (5), thus increases the magnetic field intensity at the recording bit (1-1) which requires a magnetic field intensity over a certain level. Consequently, the required magnetic field intensity is achieved with less coil (5) current, in other words, within a reasonable range of the coil's (5) temperature rise.</p> |
