High speed printer with gas-operated sheet feeding

摘要

A high speed printer for printing on sheets of porous media supplied from a stack of such sheets includes opposed pagewidth printheads. A sheet pick-up assembly is positioned operatively upstream of the pagewidth printheads. The sheet pick-up assembly has a gas conduit in fluid communication with a reversible gas supply, an outlet of the gas conduit being oriented so that the outlet is directed towards a top sheet of the stack such that a stream of gas can be directed out of the outlet and onto the top sheet to penetrate the top sheet and generate a cushion of gas between the first sheet and a second sheet to separate the first and second sheets. The reversible gas supply reverses the direction of the stream of gas back into the outlet to draw the first sheet against the outlet. A sheet feed mechanism is operatively arranged with respect to the, or each printhead and has a displacement mechanism for displacing the gas conduit to feed the first sheet from the stack.