Abstract: A kit used in TC measurement in the field includes a sandwich of 3 screens used for filtration of carrier beads from toner particles within a container. An upper 400 mesh screen has die-cut holes around its edges to allow removal of any beads trapped between the upper screen and a middle 500 mesh screen. A bottom screen of coarse 20 mesh material is used for strength to support the other screens. When a vacuum source connected to a bottom portion of the container is turned ON, the carrier beads approach the screens in the center of the container. The recirculating airflow carries the carrier beads away from the upper screen at the edges. Thus, with the upper screen being die-cut with openings around its edges, these openings allow the trapped beads to return to the inner chamber of the container for removal during cleaning.

Abstract: A method of changing a color developer in a developer housing of xerographic marking system are disclosed, and may include supplying a chart divided into a plurality of color family sections or quadrants, selecting a new color to be installed in a developer housing corresponding to the color family section, purging old toner from the developer housing until a concentration of old toner is reduced to about 0.1% to 6.0% from its nominal concentration, installing a container of a new color developer in the developer housing, and running the marking system until the required concentration of the new color developer is attained.

Abstract: A kit used in TC measurement in the field includes a sandwich of 3 screens used for filtration of carrier beads from toner particles within a container. An upper 400 mesh screen has die-cut holes around its edges to allow removal of any beads trapped between the upper screen and a middle 500 mesh screen. A bottom screen of coarse 20 mesh material is used for strength to support the other screens. When a vacuum source connected to a bottom portion of the container is turned ON, the carrier beads approach the screens in the center of the container. The recirculating airflow carries the carrier beads away from the upper screen at the edges. Thus, with the upper screen being die-cut with openings around its edges, these openings allow the trapped beads to return to the inner chamber of the container for removal during cleaning.

Abstract: A tool used in the TC measurement in the field includes a venturi shaped container that when connected to vacuum pressure from a portable vacuum cleaner takes advantage of cyclone separator functionality to assist in separation of fine toner from carrier beads with the toner being caught in the vacuum cleaner and the carrier beads being caught by a plurality of screens covering an opening in the bottom of the container.

Abstract: A method and system for a color xerographic machine determines a lower bound for the ROS power levels so that color defects are not produced by light attenuation from one or more layers of toner particles on a latent image. The method computes a minimum ROS power level for the photoreceptor at its maximum and minimum charge levels. The minimum ROS power level is the level at which the discharge voltage does not drop beyond a maximum discharge voltage difference. The difference is related to a toner particle density that affects color reproduction. The minimum ROS power levels for the minimum and maximum photoreceptor charge levels are used to compute a functional relationship for minimum ROS power levels at other photoreceptor charge levels. Thereafter, the minimum ROS power level function may be used to compute minimum ROS power levels for other photoreceptor charge levels. The computed minimum ROS power levels may be used to control the power levels used during color reproduction performed by the machine.

Abstract: This is a system for changing a color in a xerographic marking system from an old color to a new color within the same color family. The prior art systems for changing color required that the entire color housing or hardware be replaced; this was very costly since these housings are very expensive. The present system involves removing the old color, selecting a new color in the same family of color, purging this old color from the color housing until a low concentration of old color remains, then installing a new color container and running the color system with the new color until the desired color is obtained. The new color is continuously measured by a spectrophotometer until the spectrophotometer indicates that the desired new color is produced.

Abstract: A tool used in the TC measurement in the field includes a venturi shaped container that when connected to vacuum pressure from a portable vacuum cleaner takes advantage of cyclone separator functionality to assist in separation of fine toner from carrier beads with the toner being caught in the vacuum cleaner and the carrier beads being caught by a plurality of screens covering an opening in the bottom of the container.

Abstract: An enhanced toner area coverage (ETAC) sensor may be calibrated to adjust for changes in LED intensity by determining a functional relationship between specular developed mass per unit area (DMA) values and diffuse readings obtained from the sensor. Specular and diffuse readings are obtained from an ETAC sensor that senses reflected light from toner patches generated with incrementally increasing densities on the photoreceptor belt. The specular readings in a particular range and their corresponding diffuse readings are selected for the calibration computations. Reflected ratios are computed from the specular readings and used to determine specular DMAs. The specular DMAs and selected diffuse readings define a set of points for which a functional relationship is determined.

Abstract: A method for calibrating a toner concentration sensor may include obtaining a zero % TC reading from the toner concentration sensor using a carrier material, determining an estimated TC intercept, and adjusting the toner concentration sensor based on the estimated TC intercept. An apparatus for calibrating a toner concentration sensor may include a toner concentration sensor that detects toner concentration of a developer mix in a developer cartridge and a toner concentration sensor controller that applies calibration to the toner concentration sensor. The toner concentration sensor controller mat include a toner concentration sensor reading section that obtains a zero % TC reading of the toner concentration sensor based on the carrier material, a toner concentration sensor correcting section that determines an estimated TC intercept, and an adjusting section that determines for the calibration for the toner concentration sensor based on the estimated TC intercept.

Abstract: A method for maintaining developer material within in a predefined state through the scheduling of increased toner throughput coordinated among multiple developer housings. The method monitors developer material health at each developer station within a plurality of developer stations to detect unhealthy developer material. If unhealthy developer material is detected in at least one of developer stations, a toner purge state is identified for each of the remaining developer stations. Based on the toner purge states, a toner purge is performed.

Abstract: A method for operating a printing machine to maintain developer material within in a predefined state by monitoring the state of materials in a developer and automatically scheduling corrective action before print quality becomes significantly impacted. The corrective action can include forcing an increase in toner usage by periodically generating and developing images having high toner density.

Abstract: An impending fault of a component operated within a closed-loop control system can be detected. The close-loop control system is disabled. An actuator of the closed-loop control system is operated at one or more test values. A sensor reading of the actuator is taken while that actuator is operated at the one or more test values. A warning is generated if an impending fault condition is detected. An impending fault condition may be detected if the component operates at a value exceeding a maximum defined operating value, if the component operates at a value below a minimum defined operating value, or if an operating range that is narrower than a defined full operating range for the component is detected.

Abstract: Systems and methods for measuring and setting grid voltages in an image forming device may include setting a first charging device of a first image forming station to a first voltage level and setting a second charging device of the first image forming station to be off; charging a charge-retentive surface with the first charging device set at the first voltage level; measuring and the charge imparted to the charge-retentive surface by the first charging device; storing the measured charge value. Systems and methods may further include repeating the setting, charging, measuring and storing steps for the first charging device for at least one additional voltage level; and determining at least one parameter of the first charging device based on the stored measured charge values for the first charging device for each voltage level.

Abstract: A method for method for operating a printing machine to maintain developer material within in a predefined state by monitoring the state of materials in a developer and automatically scheduling corrective action before print quality becomes significantly impacted. The corrective action can include forcing an increase in toner usage by periodically generating and developing images having high toner density.

Abstract: A method for maintaining developer material within in a predefined state through the scheduling of increased toner throughput coordinated among multiple developer housings. The method monitors developer material health at each developer station within a plurality of developer stations to detect unhealthy developer material. If unhealthy developer material is detected in at least one of developer stations, a toner purge state is identified for each of the remaining developer stations. Based on the toner purge states, a toner purge is performed.

Abstract: An impending fault of a component operated within a closed-loop control system can be detected. The close-loop control system is disabled. An actuator of the closed-loop control system is operated at one or more test values. A sensor reading of the actuator is taken while that actuator is operated at the one or more test values. A warning is generated if an impending fault condition is detected. An impending fault condition may be detected if the component operates at a value exceeding a maximum defined operating value, if the component operates at a value below a minimum defined operating value, or if an operating range that is narrower than a defined full operating range for the component is detected.

Abstract: An actual tone reproduction curve of an electrophotographic system is controlled at several points to coincide with a target tone reproduction curve. The several points are referred to as level 2 control points. The level 2 control points are dynamically selected to, for example, minimize an aspect of error between the actual tone reproduction curve and the target tone reproduction curve. Test patches are generated in association with target test patch densities. Actual test patch densities are measured. An approximation of the actual tone reproduction curve is fit to the measured data. New level 2 control points are selected to minimize an aspect of deviation or error between the actual tone reproduction curve and the target tone reproduction curve. A system operative to dynamically select the level 2 control points includes means for selecting optimum level 2 control points.

Abstract: A method for determining a sensor field of view with respect to a test patch and aligning the test patch with the sensor field of view. The apparatus and method according to this invention additionally allows for utilizing the results of the determined field of view to aid in controlling the various system parameters of the image printing system.

Abstract: Method and apparatus for controlling amplifier gain, e.g., as used in ESV of a xerographic copier, has a light source, e.g., an LED, optically coupled to a gain control light dependent resistor (LDR). The LDR can be in a negative feedback loop around an amplifier. There is a voltage sensing probe located near the photoreceptor belt of the copier and coupled to an input of the amplifier.

Abstract: A light collector for directing light to a concentrated area on a target surface such as for use with a linear LED array used as an erase lamp in an electrophotographic printer. The collector includes a compound cylinder lens supported by a pair of reflecting members. The reflecting members reflect light rays from the LED array to the cylinder lens. The cylinder lens includes a lower surface for capturing the reflected light rays and a tongue extending from the lower surface for capturing light rays directly from the LED array. The cylinder lens directs and concentrates the captured light rays in a narrow line on a target surface. A plurality of cross-ribs extend between the first and second reflecting members to specularly reflect light beams from the LED array.