摘要 |
An improvement to a facsimile system which enables the simulation of 240 and 300 DPI feedwise scan resolutions in a system designed to operate at 200 and 400 DPI feedwise scan resolutions. The simulation is accomplished by feedwise advancing a document past a horizontal image scanner in defined sequences of half and full steps, half steps causing the document to be feedwise advanced by one four-hundredth of an inch (as in 400 DPI mode), full steps causing the document to be feedwise advanced by one two-hundredth of an inch (as in 200 DPI mode). The scan resolution errors introduced by the simulation are non-cumulative since the system comes back into feedwise synchronization with true 240 and 300 DPI scan resolutions each time one of the defined three operation sequences is completed. Also, a method of operating a document feeding system to approximate 240 and 300 DPI feedwise scan resolutions.
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