PERFECTING PRESS HAVING FULL DOT MEMORY

PURPOSE:To achieve cost reduction by performing both of writing and reading by letting two pages of the odd number papers and two pages of the even number papers be a unit. CONSTITUTION:The time sequence of the writing and reading of page image data performed in a full dot memory 17 is set so that the page image data of the first page is written in the area 0 of an FDM 0 at a time t1 and the page image data of the second page is written in the area 3 of the FDM 0 at a time t2 and the reading of the page image data of the second page from the area 3 of the FDM 0 and the writing of the page image data of the third page from the area 0 of an FDM 1 are performed in parallel at a time t3. The page image data of the fourth page is written in the area 3 of the FDM 1 at a time t4 and the writing of the page image data of the fifth page in the area 1 of the FDM 0 and the reading of the page image data of the fourth page from the area 3 of the FDM 1 are performed in parallel at a time t5. In similar manner, the reading of the page image data of the first page from the area 0 of the FDM 10 and the writing of the page image data of the 12-th page in the area 3 of the FDM 1 are performed in parallel at a time t12. By this constitution, pair of full dot memories of the same structure can be efficiently used.