PURPOSE: To perform data conversion to lengths of necessary cut pieces at the printing without measuring cut piece lengths except in special cases by writing the frame numbers of certain specific positions into an arithmetic device and inputting the frame numbers of reorders into the arithmetic device.

CONSTITUTION: Cut pieces are arrayed on a showcase 1 in order of frame numbers, and the frame numbers are written on the cut pieces by a writing part 2. Thence, desired printing frame numbers and printing sheet numbers are inputted to an arithmetic part 4, and are written in an OMR reader 3. Based on the results of the operation by this part 4, either an indicating piece display 5-1 or 5-3 is lighted. The cut piece C1 of the lighted display 5-1 is inserted into a negative carrier 6 from its leading end, and the piece C1 is fed leftward by feed rollers 8. At this time, the film length is detected by a pulse motor 7, the length L of the piece C1 is measured, the length L-La up to the center of the frame of the frame number is operated by the part 4 and the piece C1 necessary for printing is data-converted to length.