| 摘要 |
PURPOSE:To realize a stable and high-contrast display, by controlling the holding properties of the magnetic particles with use of a plastically fluidized powdery matter for a dispersion medium of the magnetic particles. CONSTITUTION:A plastically fluidized powdery matter 4 of the fine powdery silica or alumina which is adjusted by a dry method is used for a dispersion medium of magnetic particles 3 composed of an oxidizing magnetic mateial such as black magnetite, ferrite, etc. and a metallic magnetic material of the alloy group like iron, nickel, etc. Such dispersion medium is enclosed between a transparent surface plate 1 and an opaque rear surface plate 2. A magnet 8 is scanned on the surface of the plate 2 to cause the function of a magnetic field for attraction of the particles 3. The magnetic field has its function by a recording magnet 7 through the plate 1, and accordinaly, the particles 3 are attracted to the rear surface of the plate 1. Thus a contrast is produced to the matter 4 to perform a display. When a function of the magnetic field is caused with a level higher than the yield value of the matter 4, the partilces 3 contained in the matter 4 flow to give a clear distinction between a migration region and a nonmigration region. As a result, a high-contrast display is possible. |
