| 摘要 |
A batch sheet feeder has an upstream first conveyor section arranged to convey sheets singly in a downstream direction to a downstream second conveyor section. The second conveyor section has an upper second conveying section and a lower second conveying section forming a gap therebetween. The gap is largest at an upstream end of the second conveyor section and diminishes in size toward a downstream end of the second conveyor section. A gate positioned proximate the downstream end of the second conveyor section selectively blocks sheets fed along the second conveyor section. In another embodiment, the sheet feeder has a sheet conveyor, sheet sensor, and visual attribute sensor. The visual attribute sensor has a field of view covering an area of the conveyor at a certain downstream location so as to sense an area of any sheet on the conveyor at this downstream location. The visual attribute sensor can compare a sensed area of a sheet at the downstream location with a stored visual attribute. In this way, where the sheets of a batch are different, the visual attribute sensor can be used to verify that a sheet of a batch has visual characteristics matching those of the expected sheet at that ordinal position in the batch. This assists in ensuring a batch is not faulty. In a related method of verifying batches of sheets, for each sheet at a given ordinal position in each batch a visual attribute measure for at least an area of the sheet is obtained. A comparison is made of the visual attribute measure with a stored visual attribute measure. Each batch is selectively verified based on this comparison.
|
