| 摘要 |
Providing a magnetic-field detecting device which has a plurality of sensors the outputs of which are subjected to a differential operation, and which permits accurate detection of a magnetic field. The magnetic-field detecting device 10 is configured such that magnetism sensing portions of a pair of magneto-sensors 12 are connected in series to each other within a magnetic circuit, by a connecting member 14 which is formed of a magnetic material having a relative magnetic permeability of at least 100, a magnetic material having a relative magnetic permeability which is at least 1/100 of that of a magnetic material of the magnetism sensing portions, or the same magnetic material as the magnetism sensing portions of the sensors 12. Accordingly, both of the sensors 12 are equally subjected to an external magnetic field such as an environmental magnetic field and a magnetic background noise, and are able to detect the external magnetic field. The measuring sensor 12a is provided to detect the magnetic field generated by a subject 50, and a difference of an output of the measuring sensor 12a with respect to an output of the reference sensor 12b is obtained so as to reduce an influence of the external magnetic field, so that only the magnetic field generated by the subject 50 can be accurately detected. |
