Charge copiers

Charge generating and transporting behavior of irradiated m.etallotetrapyr-role layers is exploited in the function of colour copiers [281-284]. Suited and practically used electrophotographic photoreceptors in the copiers comprise TiPc, TiOPc, VOPc, MnPc as parts of the layers. 

Charge-transfer polymers were commercialized by IBM Corporation since about 1968 in xerographic copiers A drum covered by trinitro-fluorenone-polyvinyl carbazole polymer mixed with trinitrofluore-none replaced the expensive Se drum. 

Polyaromatics such as perylene and bis-azo pigments have been employed in low-volume copiers that normally utilize low intensity and relatively long exposures. For high-volume copiers, instead, it is necessary to employ photoreceptors with high speed and high charge photogeneration quantum... 

Figure 7 A schematic of a process in which the various steps are arranged around the circumference of a photoreceptor drum. Here, (1) is the corona charging apparatus, (2) the exposure system, (3) the development system, (4) the transfer corona, (5) the fusing apparatus, (6) the cleaning system, and (7) the erase exposure system. Processes of this kind are widely used for printer and low-volume copier applications.

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