The basic examination of the magnetic shielding structure to use for a magnetic rotation angle sensor

The magnetic rotation angle sensor has more merits such as small-sized, low cost and the low power consumption than the optical sensor. But the magnetic rotation angle sensor has the demerit to be weak to the disturbance magnetic field applied from outside the sensor, so the magnetic rotation angle sensor needs magnetic shielding structure. We proposed the magnetic shielding structure of the parallel plate type which is the simpler technique to the magnetic shielding structure of enclosing the whole sensor with the magnetic substance. We confirmed that the parallel plate type has almost the same shielding ability as the magnetic shielding structure of enclosing the whole sensor with the magnetic substance at the magnetic detecting device. We have made a prototype and evaluated angle detection error with the disturbance magnetic field. As a result, we confirmed that the error is 0.06deg when 10mT disturbance magnetic fields hang over the sensor.