| 摘要 |
PURPOSE:To prevent a sheet of paper from becoming up side down or unregistered when the opposite surfaces of the sheets are printed, by turning the sheet without changing the advancing direction of the sheet when the sheet that has left a transferring and fixing section is returned to said section. CONSTITUTION:The sheet from a hopper is sent to the transferring and fixing section 1 and the one side thereof is first printed. Then the sheet 1 is sent using a paper delivering mechanism 6 by a command from a control section 7 to a turning section 5 where the delivery of the sheet is detected, and the sheet is turned 180 deg., and the surfaces thereof are also reversed. Then the sheet is sent again to the transferring and fixing section 1, and after the other side of the sheet is printed and the sheet is sent to a stacker 5 by a command from a control section 7. In this case an optical sensor is used for detecting the arrival of a sheet, and when a sheet carried on a tray 10 cuts off the light between a luminescent element 8 and a light receiving element 6, the fact is detected by the optical sensor. Then the tray 10 is rotated 180 deg. by a rotating shaft 12. |
