A developing device of the present invention includes a conveying member for conveying a developer that is a toner and carrier mixture. The menu display controller causes, based on a sensor signal from the IR sensor, a main menu to be displayed on the display screen when an operator’s hand comes in the range. The circular member is attached to the spiral shaped member as one integral piece, each incorporating a groove around the perimeter to act as a guide for a length of string. The swaging tool applies an assembly force on the fluid connector when the fluid port is substantially covered by the fluid connector.