By making a game with greater richness in its feeling of realism, the level of interest is increased. At least one of the side walls of one, two, three, or five ribs is inclined with respect to the perpendicular ribs to avoid squealing noise. An autopilot receives instructions from a flight management system regarding a planned path and is subject to constraints preempting the planned path. This floating gate electrode has at least a partial groove therein. In forming the opaque pixel electrodes, a black matrix of the same material as the pixel electrodes is also formed on the first substrate.