Patent ID: 6025936
Filing Date: 2000-02-15
Classification: H04N

Abstract:
An image reading device comprising:a frame;a hopper for placing sheets to be read thereon;an image reading unit;a pick roller assembly for picking a sheet on the hopper and conveying the sheet toward the image reading unit, said pick roller assembly comprising a roller shaft, a pick roller rotatably and axially fitted on the roller shaft and a drive member for rotating the roller shaft;a feed roller disposed on the opposite side of the pick roller from the image reading unit so that a sheet is driven by the pick roller only, then by the pick roller and the feed roller, and then by the feed roller only, said feed roller being driven at a first rotational speed, said pick roller being driven at a second rotational speed lower than said first rotational speed;at least one projection provided on the roller shaft;at least one pawl provided in the pick roller, said at least one projection being able to engage with said at least one pawl to transmit the rotation of the roller shaft to the pick roller while the sheet is conveyed by the pick roller only, said at least one projection being able to disengage from said at least one pawl to allow the pick roller to freely rotate relative to the roller shaft while the sheet is conveyed by the feed roller only with the pick roller driven by the feed roller via the sheet; anda cushion adapted to contact the roller shaft to give a rotation load to the roller shaft to prevent rotation of the roller shaft and to reduce a load applied to the sheet conveyed by the feed roller.