The present invention is directed to novel polypeptides having homology to the mouse tex261 protein and to nucleic acid molecules encoding those polypeptides. One end of the connecting strap is attached to the first housing and another end of the connecting strap is attached to the second housing. An imaginary line of an air flow path coupling the air intake port and the air exhaust port to one another is configured to pass adjacent a center of the LED array of the first scanning unit in the horizontal scanning direction with the first scanning unit stopped at a reading position of the document transferred by a document transfer device. The multiplexed signal is used instead of the received signal 2.