Objective lens driving apparatus having bottom plate forming a projecting part

An objective lens driving apparatus comprising an objective lens which focuses light on a recording surface of an optical disk and is held by a lens holder, a focusing coil which drives said objective lens in directions approaching and receding from the optical disk, and a tracking coil which drives said objective lens in a radial direction of the optical disk, wherein the lens holder is shaped like a box having a bottom plate and opposite side surfaces, and the focusing coils are arranged on opposite sides of the objective lens so that the opposite side surfaces are orthogonal to a direction passing substantially through the centers of the focusing coils and the objective lens, the bottom plate having an entire peripheral edge which is extended from a periphery of side surfaces of the box to form a projecting part having one of (a) an extending length that is shorter in a middle part thereof than in end parts thereof along each of the opposite side surfaces of the lens holder and (b) a thickness that is thinner in a middle part thereof than in end parts thereof along each of the opposite side surfaces of the lens holder.