Abstract: The toner composition of the present invention and method to make the same includes toner particles mixed with a specific set of extra particulate additives including large colloidal silica sized 90 nm to 120 nm and having a conductivity of less than 20 ?s/cm in combination with medium size silica particles sized 30 nm to 60 nm. Optionally, additional extra particular additives such as silica sized 2 nm to 20 nm, alumina, titania or mixtures thereof can be used. The finished toner having these specific additives exhibited superior printing performance.

Abstract: A method of controlling toner development during a life of an imaging unit in an image forming device by determining whether an end of life of the imaging unit has been reached and upon a positive determination, performing at least one of incrementally lowering a target toner mass to be measured by a toner patch sensor and incrementally reducing the magnitude of voltage biases applied to at least one of the magnetic roll and the charging roll of the imaging forming device. Performing the acts of incrementally lowering and reducing are repeated until the imaging unit is replaced. The method reduces the risk of damage to the image forming device due to carrier bead development while allowing for printing to occur.

Abstract: A method of controlling toner development during a life of an imaging unit in an image forming device by determining whether an end of life of the imaging unit has been reached and upon a positive determination, performing at least one of incrementally lowering a target toner mass to be measured by a toner patch sensor and incrementally reducing the magnitude of voltage biases applied to at least one of the magnetic roll and the charging roll of the imaging forming device. Performing the acts of incrementally lowering and reducing are repeated until the imaging unit is replaced. The method reduces the risk of damage to the image forming device due to carrier bead development while allowing for printing to occur.

Abstract: A developer unit according to one example embodiment includes a housing having a reservoir for storing a developer mix that includes toner and magnetic carrier beads. A magnetic roll is mounted on the housing. An outer surface of a sleeve of the magnetic roll is positioned to carry the developer mix from the reservoir through a front portion of the magnetic roll that is exposed from the reservoir to permit transfer of toner from the outer surface of the sleeve to a photoconductive drum and back to the reservoir as the sleeve rotates in an operative rotational direction. An air vent is positioned along a rear portion of the magnetic roll for exiting air in the reservoir from the housing. An entire opening of the air vent is positioned vertically higher than the rotational axis of the sleeve when the developer unit is in an operative orientation.

Abstract: An outer sleeve of a magnetic roll for a dual component development electrophotographic image forming device according to one example embodiment includes a series of grooves in an outer surface of the outer sleeve. The grooves extend along an axial length of the sleeve and are spaced circumferentially from each other around the outer sleeve. The outer sleeve has a diameter of between 15 mm and 30 mm, inclusive. The grooves are present on the outer surface of the outer sleeve at a groove density of at least 1.91 grooves/mm of the circumference of the outer surface of the outer sleeve and a total indicated runout of the outer sleeve is 0.05 mm or less.

Abstract: An outer sleeve of a magnetic roll for a dual component development electrophotographic image forming device according to one example embodiment includes a series of grooves in an outer surface of the outer sleeve. The grooves extend along an axial length of the sleeve and are spaced circumferentially from each other around the outer sleeve. The outer sleeve has a diameter of between 15 mm and 30 mm, inclusive. The grooves are present on the outer surface of the outer sleeve at a groove density of at least 1.91 grooves/mm of the circumference of the outer surface of the outer sleeve and a total indicated runout of the outer sleeve is 0.05 mm or less.

Abstract: A developer unit for a dual component development electrophotographic image forming device includes a housing having a reservoir for storing a developer mix that includes toner and magnetic carrier beads. An axial sealing rib projects from an inner side of the housing toward the outer surface of a sleeve of a magnetic roll. The axial sealing rib extends along an axial length of the sleeve. A distal end of the axial sealing rib is positioned in close proximity to and spaced from the outer surface of the sleeve. The axial sealing rib is positioned to impede the flow of developer mix in the reservoir in a direction counter to an operative rotational direction of the sleeve.

Abstract: A developer unit for a dual component development electrophotographic image forming device according to one example embodiment includes a housing having a reservoir for storing a developer mix that includes toner and magnetic carrier beads. An auger is positioned to convey developer mix in the reservoir toward the outer surface of a magnetic roll on a front of the housing. A ledge on an inner surface of the housing extends axially with respect to the magnetic roll along a front of the reservoir. The ledge is positioned upstream from a trim bar and downstream from a pickup pole of the magnetic roll with respect to the operative rotational direction of the magnetic roll. The ledge has a concave curved inner surface that is open to the reservoir and extends from near the trim bar to near a front side of the auger.

Abstract: The toner composition of the present invention and method to make the same includes toner particles mixed with a specific set of extra particulate additives including large colloidal silica sized 90 nm to 120 nm and having a conductivity of less than 20 ?s/cm in combination with medium size silica particles sized 30 nm to 60 nm. Optionally, additional extra particular additives such as silica sized 2 nm to 20 nm, alumina, titania or mixtures thereof can be used. The finished toner having these specific additives exhibited superior printing performance.

Abstract: The toner composition of the present invention and method to make the same includes toner particles mixed with a specific set of extra particulate additives including large colloidal silica sized 90 nm to 120 nm and basing a conductivity of less than 20 ?s/cm in combination with medium size silica particles sized 30 nm to 60 nm. Optionally, additional extra particular additives such as silica sized 2 nm to 20 nm, alumina, titania or mixtures thereof can be used. The finished toner having these specific additives exhibited superior printing performance.

Abstract: A method of controlling toner concentration in an image forming device by determining a charge per unit mass of toner in a mixture of toner and carrier and adding toner to the mixture if the charge per unit mass of the toner is higher than a predetermined threshold. Other methods and devices are disclosed.