A method and system is disclosed for performing a location registration in a cellular communication network, wherein a subscriber identity of a user equipment is analyzed when a location registration request has been received, and a priority is allocated to the subscriber based on the result of the analysis. In order to allow a proper amount of toner having a proper specific electric charge to deposit on the circumferential surface of the developing roller, the blade is bent at a bending angle of at least 45 while being positioned against the circumferential surface of the developing roller when displacement amount L is at most plus 0. Since the movable pawls move outward due to their slopes, the electronic component is allowed to fit between the positioning walls.