Duplex Color Radiant Fusing

Abstract

Radiant fusing in the wavelength range between 500 nm – 10 μ m (visible – far infrared (IR C)) with continuous radiation or pulsed radiation has been used in copying and printing since the early days of commercial application of electrophotographic technology. We have evaluated the use of high intensity continuous and flash radiation for color independent radiant fusing and have chosen the UV range from 200 nm – 380 nm (UV-C – UV-A) of the spectrum which combines high intensity and low color dependency. We discuss matching of emission spectra of lamps with absorption spectra of the toners by fuser modifications, process and toner material optimization. In duplex fusing of prints for two-pass duplex electrophotographic engines, the paper goes through the fusing station twice, with the risk of reheating the first image above the softening point. Radiant fusing requires non-contact paper feeding in the heating zone followed by a non-contact paper feeding in the following cooling zone. In flash fusing we demonstrated that backside temperature of the substrate stays well below critical temperature so that conventional contact paper transport means like Kapton® belts are sufficient for duplex color flash fusing of sheet materials. Finally we discuss the potential of the technologies for future toner based high speed color production printers.