Rotary drive apparatus

A rotary drive apparatus that rotates a flywheel holding a mirror that reflects incoming light coming from a light source, and a lens that allows reflected light obtained by reflection of the incoming light to pass therethrough, the rotary drive apparatus comprising:

• a motor;
• and
• the flywheel;
• wherein
• the flywheel is supported by the motor to rotate about a central axis extending in a vertical direction;
• the flywheel includes an accommodating portion in which the lens is located;
• the lens includes:
• a base portion including a light-transmitting portion that allows the reflected light to pass therethrough;
• a first contact portion contactable with the accommodating portion on one of an upstream side and a downstream side of the base portion with respect to a direction of travel of the reflected light;
• and
• a second contact portion contactable with the accommodating portion on another one of the upstream side and the downstream side of the base portion with respect to the direction of travel of the reflected light;
• and
• at least one of the first contact portion and the second contact portion is a projection that projects from the base portion.