Abstract: A system and method for determining print cartridge authenticity in a printer includes an electrostatic process unit with a photoconductive drum configured to selectively generate a toner pattern from an associated toner cartridge based at least in part on electronic data associated with the toner cartridge. A transfer belt receives the toner pattern from the photoconductive drum and a sensor sensing the toner pattern on the transfer belt. A processor compares the toner pattern with a sensed toner pattern and generates an error condition when the toner pattern does not substantially match the sensed toner pattern. The toner includes an infrared reflective additive or an ultraviolet fluorescing additive and the sensor is configured to sense in the infrared or ultraviolet frequencies. The processor is configured to generate an error condition when the additive is not sensed by the sensor.

Abstract: A system and method for printing includes a transfer belt configured to transfer toner from a photoconductive drum of a toner-based printer to a paper. A transfer platen positions at least a portion of the transfer belt to be in proximity to a photoconductive drum. For color printing, a transfer platen is associated with a corresponding photoconductive drum for each distinct color of toner. The transfer platen is shaped to improve the transfer of toner from the photoconductive drum to the transfer belt. The transfer platen is substantially fixed in a non-rotatable position. The transfer platen includes electrically conductive foam. The transfer platen includes a low friction conductive top layer over the electrically conductive foam.

Abstract: A system and method for passively cooling electrostatic process units includes a thermally conductive housing and a doctor bar. The thermally conductive housing is disposed over the developer roller of the electrostatic process unit and conducts heat from inside the electrostatic process unit to a plurality of ribs disposed on along the length of the electrostatic process unit. Heat transferred to the plurality of ribs is dissipated through convection with surrounding air. Heat from the thermally conductive housing is also transferred through conduction to a printer chassis through contact of the thermally conductive housing with the printer chassis. The doctor bar conducts heat from the junction of the doctor blade and the developer roller to a plurality of ribs disposed on the doctor bar where the heat is dissipated through convection with the surrounding air.

Abstract: A system and method for cooling electrostatic process units includes an impeller in communication with a shaft associated with a rotating component of the electrostatic process unit such as a toner mixer, a waste auger, a developer, or a photoconductive drum. When the shaft rotates, the impeller rotates and causes air to be directed into a cooling duct. The cooling duct directs the air over one or more components of the electrostatic process unit such as the developer or a doctor blade. The air directed over the components cools the electrostatic process unit.

Abstract: A system and method for reducing toner waste during startup of a print operation for electrostatic printers includes a controller that is configured to delay the biasing and rotation of a developer roller until initially uncharged portions of a photoconductive drum have rotated past the developer roller. At the start of a print operation the controller rotates a photoconductive drum and activates a charge corona to put an initial charge on the photoconductive drum, which is thereafter selectively removed in accordance with the image to be printed. The charge corona and developer roller are angularly displaced from one another such that at the start of a print job uncharged portions of the photoconductive drum are initially rotated past the developer roller. Delaying the biasing and rotation of the developer roller prevents toner from being transferred from the developer roller to the initially uncharged portions of the photoconductive drum.

Abstract: A system and method for determining print cartridge authenticity in a printer includes an electrostatic process unit with a photoconductive drum configured to selectively generate a toner pattern from an associated toner cartridge based at least in part on electronic data associated with the toner cartridge. A transfer belt receives the toner pattern from the photoconductive drum and a sensor sensing the toner pattern on the transfer belt. A processor compares the toner pattern with a sensed toner pattern and generates an error condition when the toner pattern does not substantially match the sensed toner pattern. The toner includes an infrared reflective additive or an ultraviolet fluorescing additive and the sensor is configured to sense in the infrared or ultraviolet frequencies. The processor is configured to generate an error condition when the additive is not sensed by the sensor.

Abstract: A system and method for printing includes a transfer belt configured to transfer toner from a photoconductive drum of a toner-based printer to a paper. A transfer platen positions at least a portion of the transfer belt to be in proximity to a photoconductive drum. For color printing, a transfer platen is associated with a corresponding photoconductive drum for each distinct color of toner. The transfer platen is shaped to improve the transfer of toner from the photoconductive drum to the transfer belt. The transfer platen is substantially fixed in a non-rotatable position. The transfer platen includes electrically conductive foam. The transfer platen includes a low friction conductive top layer over the electrically conductive foam.

Abstract: A system and method for urging stray toner away from sealing areas on rotating shafts in electrostatic process units includes a shaft that is associated with a rotating component of the electrostatic process unit such as a toner mixer, a waste auger, a developer, or a photoconductive drum. The shaft includes sealing areas at either end of the shaft that are configured to prevent toner leakage through the sealing areas, and protruding ridges in the sealing areas that encircle the shaft. The protruding ridges are angled relative to the axis of the shaft such that rotation of the shaft causes the protruding ridges to urge stray toner away from the sealing areas. The protruding ridges substantially reduce toner leakage through the sealing areas of rotating shafts of electrostatic process units.

Abstract: A system and method for urging stray toner away from sealing areas on rotating shafts in electrostatic process units includes a shaft that is associated with a rotating component of the electrostatic process unit such as a toner mixer, a waste auger, a developer, or a photoconductive drum. The shaft includes sealing areas at either end of the shaft that are configured to prevent toner leakage through the sealing areas, and protruding ridges in the sealing areas that encircle the shaft. The protruding ridges are angled relative to the axis of the shaft such that rotation of the shaft causes the protruding ridges to urge stray toner away from the sealing areas. The protruding ridges substantially reduce toner leakage through the sealing areas of rotating shafts of electrostatic process units.

Abstract: A system and method for adjusting transfer parameters in electrostatic-based printers includes a sensor proximate to a paper path before a toner transfer area. A sensor comprised of opposing conductive plates determines a paper property, such as its capacitance, as it passes through an air gap between the conductive plates. A transfer roller receives an electric charge for transferring toner from an associated transfer belt to the paper with a voltage of the electric charge being adjusted based on a transfer parameter corresponding to the sensor data.

Abstract: A system and method for producing a uniform layer of toner on a developer roller of a toner-based printer includes two or more doctor blades that are configured to reduce the amount of toner deposited on the developer roller in successive steps. A first doctor blade reduces the layer of toner to a first depth, and a second doctor blade further reduces the layer of toner to a second depth. A third or subsequent doctor blade can further reduce the layer of toner to a third depth. An electrical charge applied to one or more of the doctor blades produces a substantially uniform charge to the layer of toner on the developer roller.