Rotation detection mechanism and an apparatus provided with same

摘要

An apparatus comprising planet gears 3 which rotate in engagement with a pinion gear 2 that itself rotates integratedly with the rotating shaft 12a of a motor 12 such that the planet gears 3 rotate around the periphery of the rotating shaft 12a, a carrier 4 which rotates integratedly to match the rotation of the planet gears 3 while supporting the planet gears in free rotation, and a photoreflector 9 for detecting rotation by detecting a rotation detecting part comprising a reflecting surface 4a and a non-reflecting surface 4b provided on the exterior surface of the carrier 4.