Patent attributes
A lens driving device includes a focus lens frame, first and second shafts, a rack member, a lead screw and a spring member. One or more lenses are attached to the focus lens frame. The first and second guide shafts are arranged parallel to an optical axis of one or more lenses, inserted into first and second holes of the focus lens frame and guide the focus lens frame. The rack member is supported by the focus lens frame in the vicinity of the first hole. The lead screw meshes with rack teeth formed on the rack member to move the focus lens frame along the optical axis. The spring member presses the rack teeth toward the lead screw to generate reaction force acting from the lead screw toward the rack teeth. A direction in which the reaction force acts crosses a face connecting the first and second guide shafts.