A disconnect mechanism for a power receptacle, which includes a disconnect block, a locking member slidably coupled to the disconnect block, and an electromagnetic device moveably coupled to the locking member. Second and third retardation plates arranged on a back side cause light received through a second polarizing plate from the back side to become close to circularly polarized light rotating in a second direction opposite to the first direction while passing through both of the second and third retardation plates and the liquid crystal layer in black display period. Next, the voltage on the second capacitor is compared with a reference voltage, and if the former exceeds the latter, the counter stops counting and saving the value. The host-environment independent interaction instructions represent particular interactions between some content and a hosting environment, but do not provide host-environment implementation instructions that are specific to any particular hosting environment. The CPU stores, as one file, the RTL description comprising the header portion serving as a reuse design database, and an entity portion, in a hard disk drive.