| 摘要 |
PROBLEM TO BE SOLVED: To provide a detector preventing the incoming of noise signals from the exterior while preventing an alternating magnetic field applied to a magnetic body from leaking into the exterior. SOLUTION: This detector 50 includes: an antenna device 52 equipped with an exciting coil 64 for applying an alternating magnetic field to a magnetic body 12 in a detection domain F and a detecting coil 66 for detecting a pulse signal given off by the magnetic body 12 with the magnetic field impressed thereon; a first shield member 74 provided in a position more distant from the detection domain F than the antenna device 52 is for shielding the magnetic field not to allow it to leak into the exterior; and a second shield member 76 for shielding noise signals N not to allow them to come from the exterior into the antenna device 52. Because of this, the incoming of the noise signals N is prevented while the magnetic field can be prevented from leaking into the exterior. COPYRIGHT: (C)2011,JPO&INPIT |
