| 摘要 |
PURPOSE:To obtain a high-frequency output through a simple constitution, by a method wherein a plurality of annular coils having a phase difference are monolithically formed on a substrate and in a position corresponding to a rotary multipole magnet formed in an annular manner. CONSTITUTION:A rotary multipole magnet 1 formed annularly is located so that it turns togetherwith a shaft 2. A plurality (2 pieces in the Fig.) of annular coils 11 and 12 having rectilinear parts 4 in a radial manner and corresponding to the pitch of the magnet 1 are located in a place positioned facing and opposite to the magnet. The coils 11 and 12 are formed with a conductive foil and on a substrate. When the coil 1 turns, a magnetic flux between magnetic poles crosses the rectilinear parts 4, and thereby an induced voltage having a constant phase difference is generated in the coils 11 and 12. The processing of the signal produces a signal corresponding to rotation of a high frequency. This enables to obtain a rotation signal of a high frequency without reducing the pitch of the magnet and that of the coil. |
