| 摘要 |
<p>A document feeder for advancing original document- to the imaging platen of an electrophotographic copier which is capable of operating in either a semiautomatic or fully automatic mode. In the semiautomatic mode, an original to be copied is manually inserted face up into an inlet where it is engaged by the semiautomatic transport assembly, turned around and advanced to a proper position for copying. After exposure the document is again turned around and guided into a receiving tray overlying the platen. In the automatic mode of operation, a second tray normally maintained in a remote or inoperative position is swung down to a position at which its feed end is adjacent the feeder inlet. Documents to be copied are placed face up as a stack in the second tray, and feed rollers carried by the tray are actuated to advance documents individually from the top of the stack to the inlet. A friction retarding roller engaging the bottom of the stack and the feed end is positively driven in a reverse direction to prevent the simultaneous feed of more than one document. In an alternative embodiment, the feed roller is disposed below the retarding roller to feed sheets from the bottom of the stack so that the sheets are collected in the stacking tray in their original order.</p> |
