With the aim of offering a video display technique by which stable and high contrast video images are reproduced, contrast adjusting circuitry is constructed. The utility conduit can include an electrical cable and a smokefluid evacuation hose. A gesture may be defined based on at least a count of fingers represented in multi-touch user input. Turn-on times of a plurality of lamps positioned in such a manner to overlap with a liquid crystal display panel are controlled in correspondence with the control value. A metal-containing region at least partially contacting the buried diffused ground plate is provided, the metal-containing region at least extending below the selection transistor. The present invention utilizes mixing 50% to 80% of a base rubber material with zinc diacrylate and other materials, and later mixing the entirety of the base rubber material in order to prevent adhesion and loss of zinc diacrylate.