Patent ID: 9207618
Filing Date: 2015-12-08
Classification: G03G

Abstract:
1. An electrophotographic sheet-fed front/back printing machine comprising: a sheet supply, a sheet transport conveyer, an electrophotographic printing section, a printed-sheet transport unit, a print output section, arranged in order from upstream to downstream in a direction of transport of sheets of paper, and a sheet turnover transport unit disposed upwards of the sheet transport conveyer, wherein: said sheet supply feeds out sheets one by one onto the sheet transport conveyer, said sheet transport conveyer feeds out the sheets onto an impression cylinder in the electrophotographic printing section, said electrophotographic printing section comprises an electrophotographic printing unit including a photoconductor drum, a transfer roller and said impression cylinder, whereby a toner image formed on the photoconductor drum is transferred onto the transfer roller and the toner image on the transfer roller is transferred and printed onto a sheet on the impression cylinder, said printed-sheet transport unit receives a printed sheet delivered from said impression cylinder for transporting the printed sheet to said print output section, said sheet turnover transport unit receives a printed sheet delivered from said impression cylinder for turning over the printed sheet from front to back and allowing it to fall and to be supplied onto said sheet transport conveyer, said electrophotographic sheet-fed front/back printing machine further comprises a sheet delivery region which selectively delivers a printed sheet from said impression cylinder to one of said printed-sheet transport unit and said sheet turnover transport unit, said sheet transport conveyer is provided on its sheet feed-out side with a sheet positioner for positioning a sheet longitudinally and crosswise and a sheet feed-out means for feeding out the so positioned sheet onto the impression cylinder, and said sheet transport conveyer has a traveling speed so controlled to follow a peripheral speed of the impression cylinder that it is slower than the peripheral speed of the impression cylinder when the sheet is positioned as aforesaid and that it is faster than the peripheral speed of the impression cylinder while the sheet is in transport.