The present invention relates to a method for detecting a signal, a device for detecting a signal, and a receiving device. The device converts solar energy to electrical energy via the photovoltaic effect. The zinc sulfide is wrapped in the inert foil and then treated by a HIP process to provide a low scatter water-clear zinc sulfide. During a first phase of movement of the actuator mechanism from its first to its second condition, the shield latch mechanism unlocks the blade shield from its locked blade-covering condition, and during a second phase of movement, the blade shield is moved from its blade-covering condition to its out-of-the-way condition. The application discussed here is a cardiac defibrillator but the techniques presented could be applied to other power conversion situations. The pixel includes a semiconductor layer including an oxide semiconductor layer, and the oxide semiconductor layer has a carrier concentration of less than 1\xd71014cm3.