Optical Xerography

After a review of standard xerography, it is shown that optical techniques can be used to perform all the xerographic functions (charging, exposure, transfer, fusing and cleaning) except development. ``Photoelectric charging´´ and ``induction charging´´ are described in detail, and the complicated and subtle phenomena which occur at the photoconductor interfaces are clarified. ``Persistent internal polarization (PIP)´´ is also discussed, and the role of the photoconductor interfaces and the bulk traps in the photoconductor are clarified. The spectral considerations necessary to optimize machine performance are discussed in terms of the crucial components (lamps, documents, optics and photoconductors). The new concept of ``optical transfer´´ and the use of light to aid in ``cleaning´´ are described. The use of radiation to perform xerographic fusing is described for both ``flash´´ fusing and ``radiant´´ fusing. The essential concepts necessary for achieving ``selective fusing´´ are discussed.