Abstract: A method compensates for runout errors in a web printing system. The method includes identifying runout error at a first roller driving a web of printable media, generating a runout compensation value corresponding to the identified runout error, identifying a velocity of the moving web with reference to encoder output corresponding to an angular velocity of the first roller and the generated runout compensation value, and delivering a firing signal to a print head proximate the first roller to energize the inkjet nozzles in the print head and eject ink onto the web at a position corresponding to the computed web velocity.

Abstract: A method for compensating a charge retentive imaging surface for a photoreceptor in a toner image processing machine, the surface including a plurality of panels, each panel including a document printing zone (DPZ) and an interdocument zone (IDZ), and the machine including at least one specially programmed computer, at least one sensor, and charging members for charging the surface, including: measuring for each panel, using the sensor, first density values for a plurality of points in the DPZ, the DPZ in a printing region of the photoreceptor; measuring for each panel, using the sensor, a second density value for the IDZ; determining for each IDZ, using a processor in the computer, a respective compensated IDZ density value; and modifying operation of the charging members according to the compensated IDZ density values, such that the first density values for said each panel are substantially centered with a desired density value.

Abstract: An apparatus prints on a continuous web moving in a process direction. A fiducial marker prints on a portion of the web a repeating pattern of fiducial marks at a predetermined spacing along the process direction. At least two printing stations are operatively disposed downstream of the fiducial marker, each printing station including a printhead for placing marking material suitable for a partial image on the web. A photosensor reads a fiducial mark on the web moving relative to the printing station.

Abstract: A registration system for use with an imaging device includes sensors for detecting a web speed and a web tension of a moving web and a control system configured to generate a first timing offset for at least one marking station based on the detected web speed and web tension. An image sensor is configured to generate a signal indicative of a position of a marking material applied to the moving web by at least one of the marking stations. The control system is configured to generate a second timing offset for the at least one marking station based on the position of the marking material indicated by the third signal, and to adjust an actuation time for the at least one marking station using the first timing offset and the second timing offset.

Abstract: A system suited to scheduling print jobs for a printing system includes a first processing component which identifies preliminary attributes of print jobs to be printed on sheets. A job scheduler receives the preliminary attributes and assigns each of the print jobs to one of a plurality of job queues in time order for printing. Print jobs spanning the same time are scheduled for printing contemporaneously. In one mode of operation, the assignment of the print jobs to the job queues is based on their preliminary attributes and on the application of at least one constraint which affects contemporaneous printing of at least two of the plurality of print jobs. A second processing component identifies detailed attributes of the print jobs. A sheet scheduler receives information on the assignments of the print jobs and their detailed attributes and forms an itinerary for each sheet to be printed.

Abstract: A system suited to scheduling print jobs for a printing system includes a first processing component which identifies preliminary attributes of print jobs to be printed on sheets. A job scheduler receives the preliminary attributes and assigns each of the print jobs to one of a plurality of job queues in time order for printing. Print jobs spanning the same time are scheduled for printing contemporaneously. In one mode of operation, the assignment of the print jobs to the job queues is based on their preliminary attributes and on the application of at least one constraint which affects contemporaneous printing of at least two of the plurality of print jobs. A second processing component identifies detailed attributes of the print jobs. A sheet scheduler receives information on the assignments of the print jobs and their detailed attributes and forms an itinerary for each sheet to be printed.

Abstract: Systems and methods are described that facilitate reducing temperature droop during an initial portion of a print job by reducing fuser speed to increase fuser-to-paper interaction while fuser heat is absorbed by the paper during a temperature transient. For instance, during a first N pages of a print job, where N is an integer, the paper acts as a heat sink and exerts a thermal load on the fuser roll. To compensate, fuser speed is reduced initially to ensure that a given amount of heat is applied to toner on the pages. Fuser speed is increased until fuser temperature reaches steady state. Acceleration of the fuser is also adjustable.

Abstract: In a fusing apparatus including a fuser member and pressure member fusing nip, a controller and sensors, there is provided a method of controlling fused image gloss. The method includes (a) sensing a copy sheet moving into the fusing nip; (b) sensing a temperature of a pre-fusing nip portion of a surface of the fuser member; (c) sensing a temperature of a post-fusing nip portion of the surface of the fuser member; (d) sensing an exit of each copy sheet from the fusing nip; (e) determining a start and an end of each inter-sheet gap portion on the surface of the fuser member; (f) making control calculations using sensed data; and (g) based on the control calculations, applying temperature conditioning only onto an inter-sheet gap portion on the surface of the fuser member for maintaining a near-constant uniform temperature on the surface of the fuser member.

Abstract: A fusing apparatus includes a fuser roll and a pressure roll which define a nip therebetween. An internal heat source is disposed within a interior of the fuser roll. An external heat source is disposed adjacent the fuser roll for heating an outer surface of the fuser roll. One or both of the internal heat source and the external heat source is controlled during a print job such that the thermal gradient across the fuser roll is adjusted. As a result, a temperature overshoot which generally occurs after the print job is finished can be reduced. The influence of subsequent jobs on the fuser roll surface temperature can also be accommodated.

Abstract: A registration system for use with an imaging device includes sensors for detecting a web speed and a web tension of a moving web and a control system configured to generate a first timing offset for at least one marking station based on the detected web speed and web tension. An image sensor is configured to generate a signal indicative of a position of a marking material applied to the moving web by at least one of the marking stations. The control system is configured to generate a second timing offset for the at least one marking station based on the position of the marking material indicated by the third signal, and to adjust an actuation time for the at least one marking station using the first timing offset and the second timing offset.

Abstract: A method for reducing gloss variation in prints, in an electrostatic printing system having a fuser for fusing sheets having marking particles thereon, the method including transporting a first sheet to the fuser; transporting a second sheet to the fuser; and abutting a trailing edge of the first sheet to a leading edge of the second sheet prior to the trailing edge of the first sheet entering the fuser.

Abstract: A method of measuring and correcting the Young's Modulus inline to eliminate its impact on image length variation during print runtime. The method includes intentionally perturbing the nominal operating condition of the web printing system which is controlled by the double reflex printing controller. The perturbation creates misregistration in a control target printed image that is detectable by in-situ sensors, from which Young's Modulus is estimated. Specifically, the web tension before the print zone is set differently from the web tension in the print zone to create misregistration. The error is detected by the inline sensors, and it is used to calculate the actual Young's Modulus. The implementation of the method consists of measuring the Young's Modulus at various frequencies. The correct Young's Modulus in then incorporated into the double reflex printing algorithm.

Abstract: An apparatus prints on a continuous web moving in a process direction. A fiducial marker prints on a portion of the web a repeating pattern of fiducial marks at a predetermined spacing along the process direction. At least two printing stations are operatively disposed downstream of the fiducial marker, each printing station including a printhead for placing marking material suitable for a partial image on the web. A photosensor reads a fiducial mark on the web moving relative to the printing station.

Abstract: Systems and methods are described that facilitate reducing temperature droop during an initial portion of a print job by reducing fuser speed to increase fuser-to-paper interaction while fuser heat is absorbed by the paper during a temperature transient. For instance, during a first N pages of a print job, where N is an integer, the paper acts as a heat sink and exerts a thermal load on the fuser roll. To compensate, fuser speed is reduced initially to ensure that a given amount of heat is applied to toner on the pages. Fuser speed is increased until fuser temperature reaches steady state. Acceleration of the fuser is also adjustable.

Abstract: In a fusing apparatus including a fuser member and pressure member fusing nip, a controller and sensors, there is provided a method of controlling fused image gloss. The method includes (a) sensing a copy sheet moving into the fusing nip; (b) sensing a temperature of a pre-fusing nip portion of a surface of the fuser member; (c) sensing a temperature of a post-fusing nip portion of the surface of the fuser member; (d) sensing an exit of each copy sheet from the fusing nip; (e) determining a start and an end of each inter-sheet gap portion on the surface of the fuser member; (f) making control calculations using sensed data; and (g) based on the control calculations, applying temperature conditioning only onto an inter-sheet gap portion on the surface of the fuser member for maintaining a near-constant uniform temperature on the surface of the fuser member.

Abstract: A method for reducing gloss variation in prints, in an electrostatic printing system having a fuser for fusing sheets having marking particles thereon, the method including transporting a first sheet to the fuser; transporting a second sheet to the fuser; and abutting a trailing edge of the first sheet to a leading edge of the second sheet prior to the trailing edge of the first sheet entering the fuser.

Abstract: A fusing system for use in a printing system is provided. In practice, a print media sheet having a size parameter value is transmitted to the fusing system along a first direction. Additionally, the print media sheet is provided with developer material prior to being delivered to the fusing system. The fusing system includes a fusing member positioned along a second direction for receiving the developed print media sheet. The second direction is substantially perpendicular to the first direction, and the fusing member is operated in accordance with a thermal profile that relates fusing temperature to the fusing member. The fusing system further includes a print media shifting control system for changing the position of the print media sheet relative to the fusing member in the second direction by a selected increment. The position changing of the print media sheet varies as a function of the size parameter value, and promotes uniformity in the thermal profile.

Abstract: A closed-loop toner concentration adjustment system extends xerographic process control performance with a system and method including a first controller to adjust toner concentration (TC) in a developer of the imaging device to alter a DMA level of the imaging device, the TC being adjusted based on a TC target value; a second controller to adjust an electrostatic development field to alter the DMA level; and an adjustment logic device to adjust the TC target value based on adjustments made to the electrostatic development field. The first controller outputs a dispense amount to the developer based on a difference between a measurement of the actual TC and the TC target value, thereby adjusting the TC based on the dispense amount to the developer. The second controller adjusts the electrostatic development field based on a difference between a measurement of the actual DMA level and a DMA target value.

Abstract: A closed-loop toner concentration adjustment system extends xerographic process control performance with a system and method including a first controller to adjust toner concentration (TC) in a developer of the imaging device to alter a DMA level of the imaging device, the TC being adjusted based on a TC target value; a second controller to adjust an electrostatic development field to alter the DMA level; and an adjustment logic device to adjust the TC target value based on adjustments made to the electrostatic development field. The first controller outputs a dispense amount to the developer based on a difference between a measurement of the actual TC and the TC target value, thereby adjusting the TC based on the dispense amount to the developer. The second controller adjusts the electrostatic development field based on a difference between a measurement of the actual DMA level and a DMA target value.

Abstract: The exemplary embodiments are directed to a control system and method of predicting how a machine will respond to occasional or periodic maintenance or service, and adjusting the machine accordingly to account for the change in machine behavior due to the maintenance or service action. More specifically, in a machine under closed-loop control subject to occasional maintenance or service, the maintenance or service results in transient in machine performance. To mitigate transients in machine performance due to maintenance or service, a prediction of the maintenance or service effect is fed forward the existing control system just prior to the occurrence of maintenance or service in order to compensate for the maintenance or service effect. This prediction is continually updated and refined using subsequent measurements of the effect of maintenance or service on machine performance.