In commercial electrophotographic copiers and printers, roll fusing, media handling, and toner transfer are technologies that incorporate friction drive with elastomer-coated rollers. When two rollers form a pressure nip and at least one roller is deformable, the surface strain of the deformed roller defines the length of the nip contact area and the speed of the frictionally driven roller. To insure high levels of performance from sub-systems that utilize friction drive, it is important to maintain consistent surface speeds of rollers forming a nip, under a variety of external noises, such as manufacturer tolerances, lack of roller parallelism, media thickness, media tension, and variable toner stack heights. These noises cause variations in surface strains and subsequently surface speeds, adversely impacting image quality, for example, image-to-page registration, color registration, and fusing nip dwell times.For an application that utilizes friction drive for toner transfer, an intermediate image-holding roller has been designed to conform radially with little change in shape circumferentially. The presence of a reinforcing layer just below the surface of an elastomer-coated roller enables sufficient nip contact area for electrostatic toner transfer with minimized drive variations due to external noises. The geometry and material properties of the composite roller is optimized with finite element analysis (FEA). Data from overdrive measurements confirm a reduction in speed variation, and results from a toner transfer experiment show suitable performance for high quality color printing.
Diane Herrick, Bonnie Patterson, Biao Tan, "Reinforced Elastomer Roller for Toner Transfer" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP18), 2002, pp 53 - 57, https://doi.org/10.2352/ISSN.2169-4451.2002.18.1.art00015_1