| 摘要 |
<p>PURPOSE: To improve the detection performance of a magnetic marker, regardless of a direction by constituting respective coil segments by means of mutually parallel longitudinal parts, a substantially horizontal highest part and a partially tilted base part. CONSTITUTION: A magnetic-field generating coil 37 is provided with substantially the same trapezoid-shaped coil segments 38 and 40. The two segments are substantially juxtaposed in the same direction, and one coil is arranged so as to form a mirror image of the other coil. The segment 40 is constituted so as to be shorter than the segment 38, and the longer side parts 42 and 44 at the opposite sides of the respective segments 38 and 40 are made to be at equal distance from the base part 46 of a grid. A current in the orthogonal part arranged in an opposite position is permitted to flow in both the horizontal and longitudinal directions, and a current flowing in the same direction in a horizontal part makes a magnetic field stronger by adjusting the magnetic field so as to easily detect a marker.</p> |
