A driving method of a display device that includes a display panel including a plurality of light emitting elements, is supplied with a power source voltage, and includes a saturation region and a non-saturation region according to variation of a panel current flowing to the display panel is provided. Each of the interface units includes one or more physical ports for connection to a line, and a bandwidth controller configured to control transmission bandwidth for packets received by the physical ports. The inner pipe is provided with an annular outer flange, and the sealing seat is provided with an annular inner flange.