Abstract: A method of printing includes processing a print job stream to identify one or more images to be printed on a first substrate. The first substrate has a substrate attribute, such as paper weight or surface roughness, which is different from that of a second substrate. A marking engine is selected to print the identified images on the selected first substrate. An operating parameter of the marking engine is modified from a set point for the second substrate to a modified set point for the first substrate, to accommodate the substrate attribute of the selected first substrate. The identified images are sent to the selected marking engine to be printed.

Abstract: The dielectric thickness of a photoreceptor is determined in a variety of ways, including using a relationship between threshold voltage and dielectric thickness, using a relationship between dielectric thickness and the difference between biased transfer roller (BTR) voltage and photoreceptor surface potential, using a relationship between dielectric thickness and biased charging roller (BCR) impedance, using a relationship between dielectric thickness and the slope of the DC current vs. voltage curve for the BTR or the BCR, and using a relationship between dielectric thickness and the BTR voltage at zero current. The threshold voltage can be found by using the slope of the BCR DC current vs. voltage curve, measuring photoreceptor surface potential for a plurality of target values below the charging knee to obtain the intercept value, or finding the actual value of the charging knee. A method of using the BCR as an electrodynamic voltmeter is also disclosed.

Abstract: A printing system includes a plurality of marking engines. The marking engines selectively receive at least one replacement module, such as a toner or ink cartridge. The replacement module includes a consumable such as toner or ink, which is consumed during rendering of images by the respective marking engine. A scheduling system assigns images to the marking engines for rendering on a print medium, such as paper. The scheduling system has a mode of operation in which images are selectively assigned to the marking engines to balance usage of the consumable by the marking engines.

Abstract: The dielectric thickness of a photoreceptor is determined in a variety of ways, including using a relationship between threshold voltage and dielectric thickness, using a relationship between dielectric thickness and the difference between biased transfer roller (BTR) voltage and photoreceptor surface potential, using a relationship between dielectric thickness and biased charging roller (BCR) impedance, using a relationship between dielectric thickness and the slope of the DC current vs. voltage curve for the BTR or the BCR, and using a relationship between dielectric thickness and the BTR voltage at zero current. The threshold voltage can be found by using the slope of the BCR DC current vs. voltage curve, measuring photoreceptor surface potential for a plurality of target values below the charging knee to obtain the intercept value, or finding the actual value of the charging knee. A method of using the BCR as an electrodynamic voltmeter is also disclosed.