| 摘要 |
PROBLEM TO BE SOLVED: To provide a device and a method for detecting the specifications or special features of an object to be acquired, for example, material properties, material composition and size of the object, irrespective of the distance between the device and the object. SOLUTION: The device for detection of an electrically conducting object includes a first and a second coils capable of producing simultaneously magnetic fields with opposite polarity; a third coil arranged in the region of the opposing magnetic fields; and an electronic control means for acquiring induced voltage in the third coil, during or after the supply of a current pulse to the first and second coils, or for acquiring an induced voltage in the first and second coils during the supply of a current pulse to the third coil, wherein when there is an electrically conducting object in the range of one of the magnetic fields, the electrically conducting object generates a detectable signal in the acquired induced voltage; and the current pulse comprises a step-shaped rise or a step-shaped fall in the shape of a rectangular pulse, or the like. COPYRIGHT: (C)2011,JPO&INPIT |
