| 摘要 |
PROBLEM TO BE SOLVED: To provide an acceleration sensor improved in precision of acceleration detection by eliminating an influence such as disturbance magnetic field, geomagnetism or the like and reduced in size and weight. SOLUTION: This acceleration sensor comprises a movable part 102 and magnetic sensors 104 and 105 having a magnetic-impedance effect, which are mutually opposed through a fixed gap, and the mutual displacement of the gap between the movable part 102 and the magnetic sensors 104 and 105 caused by acceleration is detected by the magnetic sensors 104 and 105, and the detected mutual displacement is converted into the acceleration of the movable part 102. The movable part 102 is formed of a magnetic plate spring magnetized in the thickness direction or a plate spring having residual magnetization, and the two magnetic sensors 104 and 105 are arranged in parallel with a prescribed vertical space to the plate spring so as to have the same magnetic field direction from the plate spring to take the difference in output between them. This sensor further comprises bias coils 109a and 109b circumferentially wound around the two magnetic sensors 104 and 104, respectively, and a means for carrying a direct current to the bias coils so as to apply a bias magnetic field of the same direction and the same magnitude to the magnetic sensors 104 and 105.
|
