To miniaturize a clutch mechanism.

This clutch mechanism is provided with a plate spring integrally rotated with a first gear disposed between the first gear and a second gear having a same rotary shaft. The plate spring is so disposed that the thickness direction of the plate spring becomes the rotary shaft direction and is formed with a projection part projecting in the rotary shaft direction, engaged with a groove part formed in the second gear, and integrally rotatably connecting the first gear to the second gear. When a rotating force of a prescribed rotation torque or more is applied to either of the first gear or the second gear, the plate spring is deformed orthogonally to the rotary shaft so as to release the engagement between the projection part and the groove part.