ORIENTATION DEVICE OF MAGNETIC FIELD FOR HARD DISK

摘要

PURPOSE:To attain the satisfactory orientation properties with a simple constitution of an orientation device by using an electromagnet to at least one of two magnetic field generators holding a substrate. CONSTITUTION:When a current changeover switch 4 is operated so that the counter poles of electromagnets 2 and 3 are different from each other, an intensive magnetic field vertical to the surface of a substrate 1 is produced between both magnets 2 and 3. The needle-shaped magnetic powder 12 contained in a film on the substrate 1 is set vertical to the substrate surface owing to said intensive magnetic field. While an intensive repulsive magnetic field is produced between the counter poles of magnets 2 and 3 in case the switch 4 is set so that those counter poles have the same polarity. Then an attracting magnetic field is strengthened between said two poles and the pole at the other side of the magnet 2. Thus a magnetic field which is horizontal to the substrate surface and parallel to the revolving direction is produced on the substrate 1. The powder 12 in the film 11 on the substrate 1 is orientated in parallel to the substrate surface owing to said magnetic field produced on the substrate 1.