| 摘要 |
PROBLEM TO BE SOLVED: To perform one-side printing at a speed twice as high as the speed of both-side printing by independently operating two color printing sets in the case of the one-side printing and connectedly operating two color printing sets in the case of both-side printing. SOLUTION: After a color image was formed on the surface of a first recording paper 100 by a first color printing set 1, it is fixed by a first fixing device 151, then the paper 100 is moved from the left to the right through a paper carrying path switching means 45 and enters a second recording paper carrying means 4. The color image is formed on the back surface of the paper 100 by a second color printing set 2 and fixed by a second fixing device 251, and the paper 100 is housed in a second stacker 252. When a second paper 200 is used, the paper 200 enters a first recording paper carrying means 3 by a paper supplying path switching means 46, then the paper passes through the same printing path as the one used in the case the paper 100 is used, so that the both-side printing is performed and the paper is housed in a second stacker 252. |
