Digital xerography

Bimolecular recombination is the recombination of an independently created electron and hole. Bimolecular recombination depends on the product of the electron and hole concentrations and can become important for high-intensity exposures such as those used in digital xerography (Pai, 1995 Jeyadev and Pai, 1996). For low-mobility materials, bimolecular recombination is usually described by a theory due to Langevin (1903)". The Langevin expression for the recombination coefficient is... 

In digital xerography, latent images are formed by the superposition of picture elements produced by exposures derived from a laser or array of light-emitting diodes. The individual picture elements are a few tens of microns in size. This places new requirements on the photoreceptor, as discussed by Chen (1990), Lutz (1995), Mort (1995), Pai (1995), and Jeyadev and Pai (1996). 

For either conventional or digital xerography, the surface potential in the nonexposed and the latent image areas must be stable with time. The nonexposed areas must be stable for the time between charging and development and the exposed areas for the time between exposure and development (these are typically between 0.2 and 2 s). The need to determine latent image quality has resulted in the development of techniques to analyze both microscopic (Yarmchuck and Keefe, 1989, 1991) and macroscopic (Kogure, 1987 Miyasaka et al., 1991 Weiss et al.. 1996 Weiss and Young,... 

While predictions of future technological requirements are not without risk, it is reasonable to assume that future applications will be mainly affected by considerations of image quality, cost, and process speed. It is also clear that digital xerography will be of increasing significance. 

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