Abstract: Beam sweeping apparatus for use in a scanning device. The apparatus comprises a mirror mounted on a pivot arm and arranged to be oscillated about an axis in an arc for sweeping a beam of light in a predetermined path. A pair of resilient are located adjacent the pivot arm to establish the limits of the excursion of the arm and mirror. A reversible electromagnetic motor is provided when energized for causing the pivot arm to move in alternate rotational directions until a portion of it engages a respective one of the bumpers, whereupon that bumper prevents further excursion of the arm in that direction and bounces the arm back in the opposite rotational direction. The energization of the electromagnetic motor is coordinated with the engagement of the bumpers by the pivot arm.