OPTICAL MAGNETIC RECORDING AND REPRODUCING DEVICE

摘要

PURPOSE:To attain the optical magnetic recording and reproduction with high accuracy by setting a flaky auxiliary magnetic pole opposite to a magnetic field generating means of an optical head part by holding a recording medium and therefore avoiding an adverse effect of the magnetic field generating means to an automatic focusing mechanism to a condensing means. CONSTITUTION:A laser beam B made incident to an objective lens 10 is focused and stopped down into a microspot on a magnetic disk 7. Thus the temperature is selectively raised up at the area irradiated by the beam B, and therefore the coercive force of the irradiated area is lowered. Both a magnetic oil 12 and an auxiliary magnetic pole 14 coact to the area S irradiated by said microspot to form a uniform magnetic field along the thickness direction. Therefore only the area S of a magnetic disk 7 is selectively magnetized toward an external magnetic field to form a microbit. The bits are formed for the 1-round course during a revolution of te disk 7. Thus the formation of bits is started to a new track obtained by giving a scan equivalent to a track performed by an optical head part H in the radius direction of the disk 7. In such a way, a microbit is formed at a recording part 7' of the disk 7 with high density and high accuracy in accordance with the input information.