Rattling of a stowable vehicle seat in a stowed state during driving is prevented, and a seat locking device and a stowable vehicle seat that reduces a returning operation load and improves returning operability is provided. A panel temperature sensor and a switch board temperature sensor are disposed in different positions of a display device. The processor may determine a color of light to filter though the areas of the flash filter based on the determined intensity of light to filter through the areas of the flash filter. An expert system module having a fault tree is guided through only a truncated portion of the fault tree based upon output from the fault recognition module. Then, a spacer is formed on sidewall of the dielectric layer. The liquid crystal layer is interposed between the first and the second substrates and functions in an OCB mode.