Mirror device and optical scanning device

A mirror device comprising:

• a mirror portion that reflects an incident ray;
• a pair of first support portions that are connected to the mirror portion on a first axis and that swingably support the mirror portion around the first axis;
• a pair of movable frames that are connected to the pair of first support portions and that face each other across the first axis;
• a pair of second support portions that are connected to the pair of movable frames on a second axis intersecting the first axis and that swingably support the mirror portion, the pair of first support portions, and the pair of movable frames around the second axis;
• a drive portion that surrounds the pair of movable frames and that has a plurality of piezoelectric actuators facing each other across the first axis or the second axis;
• a fixed frame that surrounds the drive portion;
• a pair of connecting portions that have a thinner thickness than the fixed frame and that stretch along the first axis or the second axis to connect the drive portion and the fixed frame;
• and
• a piezoelectric sensor that generates a signal corresponding to swing of the mirror portion around the first axis or the second axis,
• wherein the piezoelectric sensor is electrically isolated from the plurality of piezoelectric actuators,
• the plurality of piezoelectric actuators and the piezoelectric sensor are each formed of an upper electrode, a piezoelectric film, and a lower electrode,
• the upper electrodes of the plurality of piezoelectric actuators are connected in common via a first metal wire, and
• the lower electrode of the piezoelectric sensor is connected to a second metal wire that is electrically isolated from the first metal wire.