PLANAR TYPE GALVANOMIRROR HAVING A DISPLACEMENT DETECTING FUNCTION AND METHOD FOR PRODUCING THE SAME

摘要

The present invention relates to a small-sized thin galvanomirror for detecting the displacement angle of a mirror, which is produced by a semiconductor process. By using a semiconductor process, a movable plate (5) and a torsion bar (6) for supporting this movable plate (5) are integrally formed on a silicon substrate (2), and a planar coil (7) and a total reflection mirror (8) are formed on the upper surface of the movable plate (5). Permanent magnets (10A, 10B) and (11A, 11B) for generating magnetic fields are fixedly disposed on the planar coil (7) to thereby control the amount and direction of current to be conducted to the planar coil (7) so as to variably control the swinging angle of the movable plate (5) through the balance between a magnetic force generated and a torsional force by the torsion bar (6). Furthermore, detecting coils (12A, 12B) are provided below the movable plate (5) to thereby cause a detection current to flow to the planar coil (7) by superposing it on a driving current, whereby the detection of a displacement angle of the mirror is performed through the relative inductance variation between the planar coil (7) and the detection coils (12A, 12B) based on this detection current. <MATH>