PURPOSE: To precisely execute copy printing in terms of a necessary image area by providing a pulse signal generation means for which a dividing ratio is optionally set, controlling the driving of a latent image forming prevention means based on the counting action of dividing pulse signals whose number is in accordance with a specific image area and adjusting the period of pulse signals with the variation of the dividing ratio.

CONSTITUTION: Area specification means 31a and 31b for specifying an optional image area S in the image display surface 30 of an image display part 23 on which a microfilm image 26 is displayed and the pulse signal generation means 47a and 47b for which the dividing ratio is optionally set are provided in the titled device. The driving of the latent image forming prevention means 22 for preventing the formation of the image given from a scanning means 32 for the image 26 to an image carrier 4 is controlled based on the counting action of the dividing pulse signals whose number is in accordance with the specified image area S by the area specification means 31a and 31b. By adjusting the period of the pulse signals with the variation of the dividing ratio, the dispersion between the devices does not occur and the copy printing is accurately executed only in terms of the optional image area S. Thus, the copy printing can be precisely executed in terms of the necessary image area S.