Patent ID: 11073576

Abstract:
An object of the present invention is to selectively detect a detection magnetic field without separately providing a sensor for detecting an environmental magnetic field. A magnetic field detection device includes a magnetic field detection unit 10 that generates an output signal S1 according to a magnetic field, a first signal generation unit 20 that extracts a predetermined frequency component from the output signal S1 and generates a cancel signal S2 based on the predetermined frequency component, a first magnetic field generation unit 40 that applies a first cancel magnetic field to the magnetic field detection unit 10 based on the cancel signal S2, and a second signal generation unit 30 that generates a detection signal S3 based on the output signal S1 of the magnetic field detection unit 10 to which the first cancel magnetic field is applied. According to the present invention, a cancel signal is generated based on a frequency component of an output signal, and a first cancel magnetic field is applied to a magnetic field detection unit using the cancel signal. Therefore, it is not necessary to separately provide a sensor for detecting an environmental magnetic field. Because this configuration reduces the number of parts, downsizing and cost reduction can be realized.