US Patent 7229728 Positively-charged electrophotographic organic photoreceptor

A positively-charged electrophotographic organic photoreceptor includes an electrically conductive support, and a charge transport layer and a charge generating layer sequentially stacked on the electrically conductive support. The charge generating layer is formed by coating a charge generating layer forming composition that includes a fluorene compound, a charge generating material, a binder resin and an organic solvent on the charge transport layer, and drying. The organic photoreceptor has high sensitivity, while suppressing contamination of a charge generating layer during coating, and thicknesses of a charge transport layer and a charge generating layer may be adjusted. Also, the electrostatic properties of the organic photoreceptor, including charge potential and exposure potential, may be easily adjusted. The organic photoreceptor may be applied to an electrophotographic development system using a liquid toner having a small particle size and a high retained charge amount with an increased surface charge amount of the organic photoreceptor.