PURPOSE: To effect circular typesetting of front matter at a high precision without requiring any complicated operation by providing a host controller with a correction circuit for turning to the center, which corrects the rotation angle and position of an image so that a real pattern of the front matter may always turn to the center of the circle.

CONSTITUTION: When an operator sets fixedly a character board 37, a host controller 32A finds the width W of the front matter 2 from the fix set position of the character board 37 for selection of the front matter, and a correction circuit 52 for turning to the center find a correction angle β (counter clockwise correction by β degree) 12 for turning to the center, and corrected positions xs, ys 11. A pulse motor controller 33 turns an image turning prism 48 according to the instruction of the host controller 32A so that the character may turn by β degree, simultaneously a pulse motor 46 and a pulse motor for turning are rotated to move the typesetting position to the correction position xs, ys. Thus, the center line of the front matter may be agreed with the circle center 6.