PURPOSE: To omit resist adjustment for each machine by detecting a form with respective sensors arranged just in front of a grip roller and a resist roller, and controlling timing for writing an image by means of the detection of the grip roller.

CONSTITUTION: A grip sensor 15 and a resist sensor 16 are arranged just in front of the grip roller 13 and the resist roller 14, and in a diagonal direction, respectively. In a normal paper feeding state, writing is started based on the signal of the detection of the grip sensor 15 as a reference, the resist sensor 16 is turned on, and simultaneously, the rotation of the resist roller 14 is stopped. After the writing is started. and then, a prescribed time lapses, the carrying of the form is started by the rotation of the resist roller 14. Thus, the form 20 has deflection, and the measures of the resist adjustment, etc., are taken. On the other hand, when the form 20 is deviated and carried, the grip sensor 15 is turned on, and simultaneously, the writing is started, but after a prescribed time lapses from the start, the rotation of the resist roller 14 is stopped to correct the deviation in the form.