Patent attributes
An electromagnetic drive device includes a permanent magnet attached to a surface of a first yoke facing a second yoke; and first and second excitation coils to generate magnetic flux when being energized. The second yoke includes a base, and a first protruding part protruding from the base toward the first yoke, between the first and second excitation coils. The permanent magnet includes a first region; and second and third regions positioned on respective sides of the first region. The first region is magnetized to be a first pole, and the second region and the third region are magnetized to be second poles. The first region is opposite to the first protruding part, a boundary between the first and second regions is opposite to the first excitation coil, and a boundary between the first and third regions is opposite to the second excitation coil.