Abstract: A magnetic member includes a plurality of superparamagnetic particles held by the magnetic member. Each of the plurality of superparamagnetic particles is formed with a particle size which is set at least such that a Neel relaxation time ?n in the each of the superparamagnetic particles becomes shorter than a cycle P of an alternating current magnetic field applied to the magnetic member (?n<P) when the magnetic member is used as an electronic component.

Abstract: The data input device comprises a tablet portion made of a two-dimensional position-sensitive photodetector and a planar display element laid one on the other, and a light emitting pen forming a light spot on a light-receiving surface of the position-sensitive photodetector. The locus of the movement of the light emitting pen is displayed on the surface of the planar display element at correspond positions in accordance with the output of the two-dimensional position-sensitive photodetector, and the contents of the display provided on the planar displaying element are allowed to be delivered for subsequent processings.