A method and an apparatus are proposed for detecting at least one object in a package, in which at least one object is provided with an optical code and is disposed in a package. This light guide guides light from an LED lamp provided in the image forming apparatus main body to the surface of the photosensitive drum, thus forming a charge removing device for the photosensitive drum. An intermediate cage is provided between the inner race and outer cage having a spherical outer diameter surface with a radius of curvature matching that of the mating surface of the outer cage for maintaining constant velocity.