Embodiments of the present disclosure provide a load control method and device for a wireless communication system. A superimposing lens 930 that is a component of the integrator optical system 923 as a uniform illumination optical system is arranged such that the mounting position of the superimposing lens 930 is fine-adjustable in a direction orthogonal to an optical axis 1a. The driving-section has two rollers facing each other. The circuit layers are disposed on one of the dielectric layers, wherein the circuit layers are electrically connected with each other through the via holes and are electrically connected to the electronic devices. With a directing device, the flow path of the coating material from the material source can be set in such a way that the flow path leads optionally to the first discharge opening andor to the at least one further discharge opening. A predetermined plurality of retraction cord bases engage the ceiling for housing each retraction cord and retraction cord mechanism.