This invention is generally directed to imaging members, and more specifically, the present invention is directed to photoconductive imaging members with, for example, improved resistance to light shock and methods of using the imaging member. Light shock refers, for example, to a phenomena in which a photoresponsive imaging member when exposed to room light exhibits an increase in dark decay, increased sensitivity, collapse of the photoinduced discharge curve (PIDC) tail, reduced residual potential Vresidual, and generally adverse changes in the electrical response properties on exposure to light, and during repeating cycles of charge, exposure, and erasure, especially when the photogenerating pigment is a hydroxygallium phthalocyanine. The exposure to room light may occur, for example, during installation of the photoreceptor or during servicing of a machine, such as a xerographic machine. Thus, for example, during belt replacement or machine maintenance, nonuniform exposure of a photoreceptor to room light can result in nonuniformity in the electrical properties of the imaging member. A difference in electrical properties between exposed areas of an imaging member is undesirable because it can cause nonuniform image potentials which in turn results in the formation of nonuniform and unacceptable in many instances toner images when the light shocked imaging member is subsequently utilized for electrophotographic imaging. More specifically, the present invention relates to imaging members containing a dye, such as a yellow dye in an overcoating layer, and wherein the charge generation layer is resistant to or there is an avoidance of light shock thereof, especially at from about 400 to about 500 nanometers of light, and which light can adversely affect the photogenerating pigments present in the charge generating layer. In embodiments, the dye dopant or additive component in the overcoat layer absorbs light of wavelength less than about 700 nanometers, and more specifically, shorter than about 460 nanometers; and also wherein the dye component present in the overcoat layer is a yellow dye of, for example, the formula illustrated herein and which overcoat is comprised of a LUCKAMIDE®, a commercially available polymer, and which overcoating will prevent or minimize any light with a wavelength of about 400 nanometers to about 460 nanometers from interacting with the photogenerating layer. Examples of photogenerating pigments include hydroxygallium phthalocyanines, such as Type V hydroxygallium phthalocyanine. Processes of imaging, especially xerographic imaging, and printing, including digital, are also encompassed by the present invention.
Additionally, more specifically, the layered photoconductive imaging members of the present invention can be selected for a number of different known imaging and printing processes including, for example, multicopy/fax devices, electrophotographic imaging processes, especially xerographic imaging and printing processes wherein negatively charged or positively charged images are rendered visible with toner compositions of an appropriate charge polarity. The imaging members are in embodiments sensitive in the wavelength region of, for example, from about 400 to about 900 nanometers, and in particular, from about 550 to about 830 nanometers, thus IR diode lasers can be selected as the light source. Moreover, the imaging members of the present invention in embodiments can be selected for color xerographic imaging applications where several color printings can be achieved in a single pass.
USPTO Backgrounds
USPTO Backgrounds