Micromirror device and optical scanning device

A micromirror device comprising:

• a movable portion having a mirror portion on which a reflecting surface for reflecting incident light is formed;
• a first support portion that is connected to the movable portion on a first axis located in a plane including the reflecting surface of the mirror portion in a stationary state, and that swingably supports the movable portion around the first axis;
• a pair of first actuators that are connected to the first support portion and face each other across the first axis, each of which being a piezoelectric drive type first actuator that allows the movable portion to swing around the first axis;
• a pair of second actuators that face each other across the second axis, each of which being a piezoelectric drive type second actuator that allows the mirror portion to swing around the second axis;
• a pair of first connecting portions that is disposed along the second axis, wherein each of which connects a first actuator of the pair of first actuators and a second actuator of the pair of second actuators on the second axis;
• a fixed frame that surrounds the pair of second actuators;
• and
• a pair of second connecting portions that is disposed along the first axis, wherein each of which connects a second actuator of the pair of second actuators to the fixed frame on the first axis,
• wherein in a case where the movable portion swings around the first axis, at least a part of each first actuator of the pair of first actuators swings around the first axis in a phase opposite to a phase of the movable portion, and
• assuming that a ratio of a rotation angle of the first actuator to a rotation angle of the movable portion is R, a O value when the mirror portion swings only around the first axis is Q, and a Q value when the mirror portion swings only around the first axis in a case where the displacement of the each first actuator is 0 is Qm, 0.12<R<0.80 and Q>1.2Qm are satisfied.