PURPOSE: To restrict an eddy current by a horizontal deflecting magnetic field, to reduce the temperature rise of a magnetic substance piece, and to make it possible to stabilize the magnetic substance piece at a high accuracy, by composing the magnetic substance with a plastic mould soft magnetic substance consisting of a soft magnetic material powder and an organic insulating resin.
CONSTITUTION: A magnetic substance piece 9 is composed of 50 to 90 wt% of a plastic mould soft magnetic material powder and 1 to 50 wt% of organic insulating resin. When the magnetic substance piece 9 is used, since the soft magnetic particles 10 are covered with the organic insulating resin 11, an eddy current generated in the magnetic substance piece 9 stays only in the soft magnetic particles 10, even though the horizontal deflecting magnetic field 5 penetrates the magnetic substance piece 9 vertically, and the eddy current can be prevented from being induced to the whole body of the magnetic substance piece 9. Moreover, by using a material with a higher intrinsic resistance as the soft magnetic particles 10, the eddy current can be restricted furthermore.
NAGAI KOICHI
SAKAUCHI TADAFUMI
