MAGNETORESISTANCE EFFECT TYPE SENSOR

摘要

PURPOSE:To take out a signal component as a large output and reduce an output to approximately zero only for a noise signal by connecting two magnetoresistance effect elements in series. CONSTITUTION:Magnetic reluctant elements constituted of narrow stripe portions 3a and 3b of a uniaxially anisotropic permalloy film 3 provided on a substrate 2 are connected to each other in series to form a magnetoresistance type sensor 1. The magnetic field - resistance value curves of the stripe portions 3a and 3b are symmetrically shifted in reverse directions to each other by the bias magnetic fields due to bias magnets 4 and 5, respectively. The series connection of these two magnetoresistance elements doubles the signal component of an output voltage in response to a change in the resistance of the sensor 1 due to the magnetic field based on the record of a magnetic tape or the like and reduces the output voltage of both the magnetoresistance elements due to the magnetic field of an external noise to approximately zero due to the sum of two outputs different from each other only in polarity, enabling an S/N ratio to be increased by a simple construction.