An intelligent switch for preventing over discharge of a vehicle battery includes a switch connected to toggle between a first state for preventing current flow from the battery and a second state for allowing current flow from the battery. Program data in a target program is analyzed to identify thread-specific data and shared data. The robot textures the floor boards to exhibit the selected pattern. If there is a determined electrical failure, the power is supplied separately to the function units so that the first control unit can specify an electrically failed part based on a state of the image forming apparatus estimated at the separate supply and the detected value, and can notify a user or an administrator of the specified failed part. The configuration of the light guide reduces passage of light off-angle to the length of the light passage through the guide, such that light is directed substantially parallel to the light passage. The second metering member moves relative to the first metering member.