A rotation detection device includes a detected member that is mounted to a rotating member and has a plurality of magnetic poles arranged in a circumferential direction about a rotational axis of the rotating member, and a sensor section that is mounted to a stationary member not rotating with rotation of the rotating member and is arranged to face the detected member. The sensor section includes plural magnetic sensors each including a plate-shaped detection section that includes a magnetism detection element for detecting a magnetic field from the detected member, a signal processing circuit for processing a signal output from the magnetism detection element, and a cover collectively covering the magnetism detection element and the signal processing circuit, and wherein the detection sections are stacked in a direction along which the sensor section and the detected member face each other.

Disclosed is a galvanometer motor apparatus. The galvanometer motor apparatus includes a housing, a stator assembly, and a rotor assembly, wherein the rotor assembly includes an axle and a magnet that are coaxially arranged, and the stator assembly includes a frame and a single electromagnetic coil wound on the frame; wherein a first through hole configured to allow the magnet to rotatably run through is molded on the frame, the electromagnetic coil is disposed on a side of the first through hole, the electromagnetic coil is excitable to generate a drive magnetic field to magnetize the frame to supply a torque to the magnet, a recess configured to receive the stator assembly is molded in the housing. With such configurations, structure design is optimized, assembling is simpler, and efficiency is higher.

Disclosed is a galvanometer motor apparatus. The galvanometer motor apparatus includes a housing, a stator assembly, and a rotor assembly, wherein the rotor assembly includes an axle and a magnet that are coaxially arranged, and the stator assembly includes a frame and a single electromagnetic coil wound on the frame; wherein a first through hole configured to allow the magnet to rotatably run through is molded on the frame, the electromagnetic coil is disposed on a side of the first through hole, the electromagnetic coil is excitable to generate a drive magnetic field to magnetize the frame to supply a torque to the magnet, a recess configured to receive the stator assembly is molded in the housing. With such configurations, structure design is optimized, assembling is simpler, and efficiency is higher.