PURPOSE: To make arbitrary characters, symbols, etc. easily on the original plate of a positive film by the use of an electronic computer system having a conversion type graphic display, etc., and a photoplotter.

CONSTITUTION: In accordance with an original, the operator inputs characters, symbols and their positions into a conversation type graphic display device 39 by using a keyboard 1, a tablet 3, an electromagnetic pen 11, and a command menue 12, corrects, deletes and adds these while viewing a graphic monitor display device 2, and feeds data to a central processor 4. In the processor 4, the driving data of a photoplotter corresponding to the thickness of the data are outputted to a magnetic tape 6 or directly online to a photoplotter driving device 7. The driving data outputted to the tape 6 is inputted offline to the photoplotter driving device. The photoplotter driving device controls the operation of the photoplotter by means of the driving data and exposes a positive film.