Rotary reciprocating actuator and optical scanning device

A rotary reciprocating actuator comprising:

• a movable member including a shaft part with a magnet fixed on an outer periphery, wherein a V-shaped mirror is held such that a ridgeline of the V-shaped mirror is along the shaft part, and the movable member is supported in a rotatable manner back and forth around an axis through the shaft part;
• and
• a unit body including a plurality of magnetic poles, a coil member, and a magnetic member, the plurality of magnetic poles facing the magnet in a radial direction of the shaft part and being separated from each other in a circumferential direction of the shaft part, the coil member being configured to form, together with the magnet, an electromagnetic drive part configured to rotate back and forth the movable member, the magnetic member facing the magnet in the radial direction of the shaft part and being disposed between the plurality of magnetic poles in the circumferential direction to bias the movable member toward an initial position of back- and forth rotation by attracting the magnet,
• wherein the electromagnetic drive part sways the V-shaped mirror while maintaining an angle of the V-shaped mirror by rotating back and forth the movable member.