A SAW chip where ones are balanced signal terminals and the others are unbalanced signal terminals is mounted on a mounting board in a flip chip manner, and the mounting board and a surface of the SAW chip are covered with resin. The image forming device includes a channel through which toner is moved. An object of the invention is to prevent the crosstalk between the light-emitting device and the light-receiving device. A FSM whose memory region includes the first address may be selected.