Abstract: A printer or other marking engine includes a marking material transfer device, such as a photoreceptor drum or belt, that includes a plurality of pitches. Each pitch receives an individual color of marking material and conveys the marking material to a substrate. The marking engine forms a desired image in a main image area of the substrate using marking material from one or more of the pitches, and produces a target patch pattern for each of the pitches in a margin area located outside the main image area. A measuring device such as a spectrophotometer is used to measure each target patch pattern, and based on the measured values, an individual color calibration is performed for each pitch for use in a subsequent marking operation. The color calibration may include generating or modifying a tone reproduction curve for each pitch based on the measured values. The margin area may be later trimmed off, thereby removing the portion of the substrate on which the target patch pattern is formed.

Abstract: A method of measuring and controlling high frequency banding, the method includes creating a test pattern, sensing the test pattern with optical sensors, determining a beat frequency based on the sensed test pattern, and determining the frequency, phase and amplitude of high frequency banding based on the beat frequency. An exemplary embodiment of a feedback control method for controlling high frequency banding includes creating a test pattern, sensing the test pattern with optical sensors, measuring high frequency banding and adjusting the imaging parameters based on the measured high frequency banding in order to decrease the extent of high frequency banding. Moreover, an exemplary embodiment of a system for measuring high frequency banding includes an image marking device having a receiving member, optical sensors arranged on the receiving member, and a controller that is functionally coupled to the optical sensors and to the marking device.

Abstract: Systems and method provide compensation for temperature induced peak wavelength shift of LEDs is color parameter measuring systems that use a model to reconstruct target color parameter values from the reflectance values measured when the target is illuminated by LEDs. Several models may be constructed, with each model being trained at a unique temperature, resulting in a set of models that span the temperature range of interest. In real-time, the LED based color parameter measuring system measures the temperature and interpolates between the models to estimate the appropriate model to use at the temperature of interest. The estimated model is then used to perform the color parameter value estimation.

Abstract: A device to measure toner concentration can include a selector that selects a type of developer material to be measured and a sensor that detects an amount of light reflected off a developer material. A controller within the device can determine a value corresponding to a toner concentration of the developer material based on the amount of light detected by the sensor.

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: What is disclosed is a method for maintaining consistent color output across printers even when the inline sensors have differences in accuracy due to various technical and environmental factors. A spectrophotometer is used to measure the color quality of printed references. Adjustments are then iteratively made until reference charts of desired color quality are obtained. The printed reference allows one to achieve relatively high system performance by removing sensor inaccuracies. Using the printed reference measured by the inline sensor control systems of each machine are calibrated. At customer sites and at suitable intervals, a reference document can be read using the inline sensor on a reference machine and any differences from expected values can be calibrated out.

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: 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 electrostatic type voltmeter for measuring the potential on a surface, the voltmeter including a probe; a support for supporting the probe in spaced relationship with the surface, the probe having a plurality of spacing element sites thereon for measuring a distance between each of the plurality of spacing element sites and a corresponding area on the surface opposite of each of the plurality of spacing element sites; a plurality of electrostatic element sites, intermixed and adjacent to the plurality of spacing element sites on the probe, for measuring a voltage between each of the plurality of spacing element sites and an area on the surface adjacent to the corresponding area opposite of each of the plurality of spacing element sites. A processor for compensating an output signal of the probe in response to the measurements received from the plurality of spacing element sites and the plurality of electrostatic element sites.

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 development system is provided that extends the functionality of liquid developer to produce custom colors and combines it with a powder development engine to enable custom color printing. An apparatus for developing an image on an imaging surface, including: a first developer unit having dry marking particles therein for developing a first portion of the image; and a second developer unit having a solution of marking particles and liquid carrier therein for developing a second portion of the image.

Abstract: A development system is provided that extends the functionality of liquid developer to produce custom colors and combines it with a powder development engine to enable custom color printing. This invention provides a apparatus and method, control scheme, hardware, and software, necessary for enabling custom color printing using an electrophotograpic hybrid technology.

Abstract: An image forming system and method of using the system includes a development station for developing an image, a replenishing source that stores toner mixed to a desired color and comprising at least two toner component colors, a conditioning station that conditions the toner before sending the toner to a developing station, and a drawing device that draws a portion of the toner in the conditioning station. The drawing device will remove a portion of at least one component color of the toner until the desired color is suitable for developing. The system and method will help to produce images of a desired color in liquid immersion development of color prints. With the use of the drawing device, consistent colored images can be achieved while reducing waste of toner.

Abstract: A development system is provided that extends the functionality of liquid developer to produce custom colors and combines it with a powder development engine to enable custom color printing. An apparatus for developing an image on an imaging surface, including: a first developer unit having dry marking particles therein for developing a first portion of the image; and a second developer unit having a solution of marking particles and liquid carrier therein for developing a second portion of the image.

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.