Abstract: A method of monitoring one or more patches in an image-processing device comprised of photoreceptor, a controller, and a sensor, includes obtaining specular readings and diffuse readings from the one or more patches and computing values received from the readings. In addition, the one or more patches are from about 0.1 mm to equal or less than the field of view of the sensor where each patch size, location, and approximate value is known; and an analysis of variance (ANOVA) is automatically conducted from the known size, location, and approximate value of each patch.

Abstract: A method and apparatus for implementing statistical process control (SPC) in a printing environment to address errant reads of control sensors is provided. The system uses SPC, in systems having feedback control based on control sensor data, to identify errant reads and ensure that such errant reads are not used in the applicable feedback loop. Unnecessary reaction to the errant reads is thus avoided.

Abstract: A toner concentration control system for maintaining image quality in a developer structure, the toner concentration control system including: a transfer efficiency estimator for measuring a transfer efficiency estimate associated with a developed image on an imaging surface before and after transfer; and a toner dispenser, responsive to the transfer efficiency estimator, for adjusting a toner dispense rate.

Abstract: A method of controlling an actuator includes determining a function of an actuator value based on a cost function index that represents a relationship between a tone reproduction curve error and the actuator value necessary to achieve a tone reproduction curve target, determining an actual tone reproduction curve error from an obtained sample of a tone reproduction curve and controlling the actuator based on the function and actual tone reproduction curve error to move to a point that represents the tone reproduction curve target. A Xerographic system includes an actuator, an input device that inputs the cost function index and a controller that controls the Xerographic system to obtain the sample, determine an actual tone reproduction curve error from the sample, and control the actuator based on the cost function index and the actual tone reproduction curve error to move to a point that represents the tone reproduction curve target.

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.

Abstract: A feedback control method for controlling an ununiform banding on a photoreceptor is disclosed that includes arranging optical sensors on a photoreceptor, transferring an amount of toner on a piece of paper, measuring the resulting amount of banding, and adjusting the parameters to decrease the amount of banding. A method of measuring low deposited masses of a substrate is disclosed, using either ETAC optical sensors or full width array sensors. Finally, a copy is disclosed including at least one of NC2 array sensors and ETAC sensors, a developer roll voltage source, a ROS intensity source, an input device and a controller.

Abstract: Systems and methods of controlling banding defects on a receiving member in an imaging or printing process using a feedback and/or feedforward control technique. In one exemplary embodiment, a method of controlling banding defects on a receiving member in an imaging or printing process includes (a) determining a toner density on the receiving member, (b) automatically determining the extent of banding on the receiving member by comparing the determined toner density to a reference toner density value, and (c) automatically adjusting the toner density based on a result obtained from the comparison of the measured toner density to the reference toner density value, automatically determining the extent of banding and automatically adjusting the toner density being performed using a feedback and/or feedforward control routine or application.

Abstract: An apparatus for developing a latent image recorded on a movable imaging surface, including: a reservoir for storing a supply of developer material including toner particles, said reservoir including a transport member; a donor member being arranged to receive toner particles from said transport member and to deliver toner particles to the image surface at locations spaced apart from each other in the direction of movement of the imaging surface thereby to develop the latent image thereon; a power supply, connected to said donor member, for biasing said donor member to deliver toner to the image surface during a printing mode of operation; a second power supply, connected to the transport member, for maintaining a predefined voltage difference between the transport member and the donor member such that toner particles are attracted to the donor member from the transport member during a printing mode of operation; a controller for generating a donor member purge signal trigger based on sensed or calculated dev

Abstract: A method for sensing toner concentration in a developer housing with an optical system containing developer material including toner and carrier, the method, including: emitting light with the optical system through a viewing window in the developer housing onto developer material in the housing; sensing the light reflected off the developer material with the optical system; calculating a toner concentration measurement based upon the sensed light reflected off the developer material; and compensating the toner concentration measurement to account for optical variation due to the developer material condition.

Abstract: An apparatus and method for determining toner concentration of a sample comprised of toner and carrier, including exposing the sample to light; the exposing includes emitting light at a predefined wavelength based upon the color of the toner; detecting the light reflected off the sample with an optical sensor; and determining the toner concentration of the sample base upon the light reflected off the sample.

Abstract: A method for sensing toner concentration in a developer housing with an optical system containing developer material including toner and carrier, the method, including: emitting light with the optical system through a viewing window in the developer housing onto developer material in the housing; sensing the light reflected off the developer material with the optical system; calculating a toner concentration measurement based upon the sensed light reflected off the developer material; and compensating the toner concentration measurement to account for optical variation due to the developer material condition.

Abstract: An apparatus and method for determining toner concentration of a sample comprised of toner and carrier, including exposing the sample to light; the exposing includes emitting light at a predefined wavelength based upon the color of the toner; detecting the light reflected off the sample with an optical sensor; and determining the toner concentration of the sample base upon the light reflected off the sample.

Abstract: An apparatus (100) for measuring toner concentration in a developer contained in a developer housing (10) includes a developer sample container (102) that receives a portion of developer extracted from the developer housing (10). A spectrophotometer (112) measures spectrophotometric data for the portion of the developer in the developer sample container (102). A processor (116) estimates the toner concentration based on the measured spectrophotometric data and a pre-determined relationship (118) between the spectrophotometric data and the toner concentration. A method (200) for estimating the toner concentration in a developer comprising a toner and a carrier includes measuring (220) a color characteristic of the developer, comparing (222) the measured color characteristic with a pre-determined relationship between the color characteristic and the toner concentration, and estimating (226) the toner concentration based on the comparing.

Abstract: A developer composition having improved noise signal ratio in an optical toner concentration sensing system, including a toner having a first diffuse reflectivity and a carrier having a second diffuse reflectivity wherein the difference between the first diffuse reflectivity and the second diffuse reflectivity is substantially high.

Abstract: A color marking system includes a control system for maintaining an accurate representation for approximating color space transformation comprising a set of piecewise homeomorphisms. The homeomorphisms and parametric models are selectively adjustable in accordance with printer/display calibrating data. Preferably the homeomorphisms comprise corresponding tetrahedra with domain and co-domain color spaces. If error above a selected level is detected, the tetrahedra are adjusted by calculating new locations for their vertices having a consequence of recomputation of model parameters and converging parametric model performance in accordance with a predetermined objective of the system. An inverse of the model is used for feedforward control of the marking system.

Abstract: A toner maintenance system for an electrophotographic developer unit, including a sump for storing a quantity of developer material comprised of toner material; a first member for transporting developer material from the sump, a viewing window, in communication with toner material, in the sump; an optical sensor, for measuring reflected light off the viewing window and toner material, and generating a signal indicative thereof. A toner concentration controller is adapted to receive a signal from the optical sensor and to generate an “Add Toner” signal to replenish toner material in the sump.

Abstract: A developer composition having improved noise signal ratio in an optical toner concentration sensing system, including a toner having a first diffuse reflectivity and a carrier having a second diffuse reflectivity wherein the difference between the first diffuse reflectivity and the second diffuse reflectivity is substantially high.

Abstract: A toner maintenance system for an electrophotographic developer unit, including a sump for storing a quantity of developer material a sump for storing a quantity of developer material comprised of toner material; a first member for transporting a mixture of developer material and toner particles from the sump, a viewing window, in communication with toner material, in the sump; an optical sensor, device for measuring reflected light off the viewing window and toner material, and generating a signal indicative thereof. A toner concentration controller is adapted to receive a signal from the sensor and to generate an “Add Toner” signal to replenish toner in the sump.

Abstract: An apparatus (100) for measuring toner concentration in a developer contained in a developer housing (10) includes a developer sample container(102) that receives a portion of developer extracted from the developer housing (10). A spectrophotometer (112) measures spectrophotometric data for the portion of the developer in the developer sample container (102). A processor (116) estimates the toner concentration based on the measured spectrophotometric data and a pre-determined relationship (118) between the spectrophotometric data and the toner concentration. A method (200) for estimating the toner concentration in a developer comprising a toner and a carrier includes measuring (220) a color characteristic of the developer, comparing (222) the measured color characteristic with a predetermined relationship between the color characteristic and the toner concentration, and estimating (226) the toner concentration based on the comparing.