Patent attributes
A deflector includes a vibrating mirror supported by a torsion beam provided as a rotational axis and reciprocally scanning a beam from a light emitting source; and a rotational part configured to give a rotational torque to the vibrating mirror for making oscillation. The rotational part generates the rotational torque along one side separated from the rotational axis by length R in a direction perpendicular to the rotational axis. The vibration mirror has relationships ofR<r,D>d,and D≧d·(r/R)^2where width in a direction perpendicular to the rotational axis of a mirror part that is a part of the vibrating mirror is 2r; width in a direction parallel with the rotational axis of the mirror part is d; and width of the separated one side causing generation of the rotational torque is D.