PURPOSE: To simplify the unit, by attaching a mark on the center binding area of bank book in advance, reading in this mark in parallel with the scanning of the print page with the print mark sensor, and inhibiting the read-in while the center binding area is scanned to make unnecessary the position detection sensor.

CONSTITUTION: The timing mark TMFA of broad width is attached in advance at the center binding area FA, SL of the bank book PB, the hyphen mark sensor HMS and the timing mark sensor TMS are made parallelly for the scanning, and the identification of the areas FA, SL is made by reading in the mark TMFA. Further, the scanning of the print page is continued until the mark HM of the final booked line is read in with the sensor HMS, and the line set circuit 32 is set via the AND circuit 31. The inverted output of the sensor TMS is fed to the circuit 31, and the set of the circuit 32 is inhibited when the mark TMFA is read in, the check pulse generating circuit 37 and the line set correction circuit 39 perform specified line correction with the output to set the circuit 32.