Lens barrel with internal motor focusing

摘要

A lens barrel includes a stationary tube secured to the inner side of a stationary lens barrel member with a given space kept between them, and a motor disposed within the space. A helicoidal surface is arranged along the inner circumference of the stationary tube to be in screwed engagement with the helicoidal surface of a lens-carrying frame arranged to carry lenses which are shiftable in the direction of their optic axis, and a connecting member extends to the inner circumference of the stationary tube to cause the rotation of a rotary tube which has a toothed part engaging the output gear of the motor to be transmitted to the lens-carrying frame.