Abstract: A process for toner preparation includes forming toner particles by mixing an emuslion comprising at least binder resin and a colorant, aggregating the toner particles, and blending external additives with the toner particles in a blender to form a toner, wherein the blender has a blend intensity of from about 90.5 to about 100.5 W/lb, a specific blend energy of from about 20.3 to about 35.3 W-h/lb and a blender loading density of from about 0.25 to about 0.55 lb/L.

Abstract: Using a document scanner or other image input device of an image or document processing system to periodically scan or image printed test images from a plurality of marking engines replaces internal sensors as a feedback means in image quality control. For example, image lightness (L*) is controlled by periodically printing mid-tone test patches, scanning the printed test patches with a main job document scanner and analyzing the scanned image to determine updated marking engine actuator set points. For instance, ROS exposure and/or scorotron grid voltages are adjusted to maintain image lightness consistency between marking engines.

Abstract: A method for minimizing toner usage in minimum area coverage patches in a color printer including: reviewing a print job including job images; performing a pixel count for each color plane on a sheet level of the print job; converting the pixel count to a percent area coverage per color plane; in feed-forward mode comparing the area coverage per color plane to a reference value; activating or inactivating a color station depending on the comparison of the area coverage per color plane to the reference value; and printing a MAC patch of variable size with the color station if the area coverage per color plane is substantially less than a reference value.

Abstract: A method for minimizing toner usage in minimum area coverage patches in a color printer comprising: reviewing a print job comprising job images; performing a pixel count for each color plane on a sheet level of the print job; converting the pixel count to a percent area coverage per color plane; in feed-forward mode comparing the area coverage per color plane to a reference value; activating or inactivating a color station depending on the comparison of the area coverage per color plane to the reference value; and printing a MAC patch of variable size with said color station if the area coverage per color plane is substantially less than a reference value.

Abstract: An image transfer apparatus with the capacity to reduce or clean wire history. The cleaning is performed by supplying a voltage burst to shift, relative to nominal, the D.C. component of the electrode bias relative to the electrical bias of the donor member during the movement of the inter-imaging region through the development zone. A voltage shift may also be applied to electrically bias the donor member relative to the photoreceptor belt during the movement of the inter-imaging region through the development zone. These voltage shifts may be conducted individually or simultaneously.

Abstract: In a color analysis method in which sheets with multiple different color printed test patches are moved relative to a color analyzing spectrophotometer, and in which fiducial marks are printed adjacent to respective test patches and optically detected by a fiducial mark detector to provide a triggering system for the respective test patch analysis, there is provided automatic diagnostic testing of the spectrophotometer and the fiducial mark triggering system, including automatically generating special test sheets, some of which may include test areas of varying density black.

Abstract: An image transfer apparatus with the capacity to reduce or clean wire history. The cleaning is performed by supplying a voltage burst to shift, relative to nominal, the D.C. component of the electrode bias relative to the electrical bias of the donor member during the movement of the inter-imaging region through the development zone. A voltage shift may also be applied to electrically bias the donor member relative to the photoreceptor belt during the movement of the inter-imaging region through the development zone. These voltage shifts may be conducted individually or simultaneously.

Abstract: In a color analysis system in which sheets with multiple different color printed test patches are moved relative to a color analyzing spectrophotometer, and in which fiducial marks are printed adjacent to respective test patches and optically detected by a fiducial mark detector to provide a triggering system for the respective test patch analysis, there is provided automatic diagnostic testing of the spectrophotometer and the fiducial mark triggering system, including automatically generating special test sheets, some of which may include test areas of varying density black.

Abstract: In an electrostatic and development control in a printing apparatus, unwanted variation in dot size and shape may be stabilized and the DMA variability under halftone control may be decreased, by use of a novel halftone discharge ratio (HTDRmidtone) along with the conventional actuators of development potential, cleaning potential, and exposure level. A three-input, three-output MIMO control system may be constructed to deliver superior regulation of halftone and solid area image quality with use of control algorithms that are based on the halftone discharge ratio and with use of as few as two developed halftone test patches.

Abstract: A method and apparatus in an electrostatographic reproduction machine having a plurality of development units for reliably producing high quality toner particle images under varying sustained area toner coverage conditions.

Abstract: Reload characteristics of a development member such as a donor roll are monitored by using a machine exposure system (ROS or LED Bar) to generate a test image composed of a short (in the process direction) high density solid area patch followed by a long mid and lower density areas (solid or halftone), the later corresponding to Reload Defect (RD) exhibited by the development member. Typical dimensions of the test image would be a 15 mm square high density patch followed by a 200.times.15 mm mid and lower density regions. This test image voltage profile is placed in a skipped image frame inserted into a long job, or is effected during cycle-out/down following a shorter job run, and is scheduled at infrequent periodic intervals, for example, every 2000 prints. The resultant developed toner pattern on the photoreceptor is monitored, for example, with a reflectance or transmission density sensor such as the Toner Area Coverage (TAC) sensor used in the 4700.TM., 4850.TM., and 5775.TM.

Abstract: A method of compensating for toner cohesivity within a repository in a developer system by recording toner consumption rate and toner dispense rate over a given time within the developer system. A control responds to the toner consumption and dispense rates over the given time period to compute toner residence time in the repository and estimate a degree of toner cohesiveness. The control then projects an adjustment to the development voltage to suppress the effects of toner cohesivity.

Abstract: A printing system using a recharge, expose and development image on image process color system is disclosed in which there is an optional extra black development step. The printing system may be a single pass system where all of the colors are developed in a single pass or a multi-pass system where each color is developed in a separate pass. The additional black development step results in optimal color quality with black toner being developed in a first and/or last sequence. Having more than one black development station allows low gloss and high gloss black toner to be applied to the same image, enabling the very desirable combination of low gloss text and high gloss pictorials on the same page.

Abstract: A developer control for enabling the use of developer and toner materials with widely varying At in high quality xerographic copying and printing. Pixel count data is combined with toner test patch reflectance data during a brief toner rundown to determine the rate of change of density per unit change in toner concentration. During toner rundown, dispensing of toner is suspended for a period of time for effecting toner concentration reduction by approximately 0.25%. The change in Toner Concentration (TC) is estimated using pixel counting. Additionally, toner test patches are created and the reflectance thereof is measured for determining the change in toner density. The estimated TC change and the change in toner density are processed using linear regression to find the average change in density sensor output for the estimated change in TC which is referred to as the rundown slope. The rundown slope is then compared to a target value.

Abstract: An automatic xerographic set up and monitoring process for a multi-mode electrostatographic machine in which a corona charge intercept value is obtained and used to optimally set corona charging levels for different modes, optimum flash exposure levels obtained, ID lamp intensity correlated with flash exposure levels, and xerographic process parameters set for each different mode.

Abstract: An automatic xerographic set up and monitoring process for a multi-mode electrostatographic machine in which a corona charge intercept value is obtained and used to optimally set corona charging levels for different modes, optimum flash exposure levels obtained, ID lamp intensity correlated with flash exposure levels, and xerographic process parameters set for each different mode.

Abstract: An automatic xerographic set up and monitoring process for a multi-mode electrostatographic machine in which a corona charge intercept value is obtained and used to optimally set corona charging levels for different modes, optimum flash exposure levels obtained, ID lamp intensity correlated with flash exposure levels, and xerographic process parameters set for each different mode.

Abstract: An automatic xerographic set up and monitoring process for a multi-mode electrostatographic machine in which a corona charge intercept value is obtained and used to optimally set corona charging levels for different modes, optimum flash exposure levels obtained, ID lamp intensity correlated with flash exposure levels, and xerographic process parameters set for each different mode.

Abstract: An electrophotographic printing machine in which a controller regulates charging of a photoconductive member in accordance with information stored therein. The controller determines the charging current as a function of the rest time between successive copying cycles.

Abstract: An apparatus in which toner particle concentration within a developer mixture and charging of the photoconductive surface are controlled. A first test area and a second test area are recorded on the photoconductive surface. Toner particles are deposited on the first test area having a greater density than the toner particles deposited on the second test area. Concentration of toner particles within the developer mixture is controlled in response to the toner particle density of the first test area. Charging of the photoconductive surface is regulated in response to the toner particle density of the second test area.