Canon iR6570 series Service Manual page 294

Chapter 8
7. The 2nd side is printed on the 1st sheet.
The 2nd sheet is moved to the duplexing wait point.
The 4th sheet is picked up.
8. The 7th side is printed on the 4th sheet, and the 1st sheet is delivered.
9. The 4th side is printed on the 2nd side, and the 3rd sheet is kept on hold at the duplexing wait point.
The 5th sheet is picked up.
10. The 2nd sheet is delivered.
The 9th side is printed on the 5th sheet.
8-30
F-8-36
F-8-37
F-8-38
F-8-39