Patent ID: 8534663
Filing Date: 2013-09-17
Classification: B65H

Abstract:
1. An automatic document feeder, comprising: a paper pick-up device for transmitting a paper into said automatic document feeder; a shaft located downstream of said paper pick-up device, and rotated at a first speed; a first roller sheathed around said shaft; a second roller disposed on said shaft for transmitting said paper, wherein a diameter of said second roller is greater than a diameter of said first roller, wherein said second roller is driven to be rotated at a second speed by said shaft; a first idler located upstream of said shaft for performing a skew correction on said paper, wherein said first idler is driven to be rotated by said first roller; a second idler, wherein said second idler is just disposed over the second roller, wherein said second idler is driven to be rotated by said second roller; and a power-coupling device disposed on said shaft, and located at a side of said first roller, wherein when said power-coupling device is connected with said shaft and said first roller, said first roller is driven to be rotated at a third speed by said shaft, and said first idler is driven to be rotated by said first roller to start to transmit said paper, wherein when said paper is transmitted through said first roller and said second roller simultaneously, said first roller is driven to be rotated at said second speed by said paper, so that a power connection between said shaft and said first roller is released by said power-coupling device, wherein said second speed is higher than said third speed, wherein after said paper is completely departed from said first roller and during said power connection between said shaft and first roller is established by said power-coupling device again, said first roller and said first idler reach a static status.