Abstract: Method and apparatus for duplex electrostatic imaging wherein a toner image is transferred and simultaneously fixed to two sides of a receptor medium using high pressure. The first toner image is created on a dielectric image roller and pressure transferred to a transfer roller moving at an identical surface velocity. A second toner image is subsequently formed on the image roller, and the two images are simultaneously transferred and fused to opposite sides of a receptor sheet at the nip. The image roller advantageously includes a hard, very smooth dielectric surface, while the transfer roller has a moderately smooth, compliant surface. The transfer roller surface preferably comprises an engineering thermoplastic or thermoset material characterized by a relatively low coefficient of friction in order to provide high transfer efficiency to the receptor sheet. The duplex imaging apparatus may be incorporated into electrostatic printers and copiers with suitable adaptations in the image generating stages.

Abstract: A system for ink jet printing to collect ink unused during the printing process, and recycle the ink solvent to be reintroduced in the system. The ink stream, after breakup into individual droplets, is selectively charged in a charging tunnel and then passes between a deflection electrode and a collection electrode. The charged droplets are electrostatically deflected to the porous wall of the collection electrode, where they are absorbed. A vacuum pump draws the absorbed droplets into a collection container, which vaporizes the ink solvent and mixes it with air. The solvent-laden air passes through a filter, and is forced through the wall of the deflection electrode in order to control the drying of stray ink drops between the two electrodes.