Abstract: Techniques are disclosed that enable fine features such as serifs and narrow strokes of texts to be produced by xerographic devices, for example. The fine features may be generated by subpixels which are produced when a pulse width used to image a pixel is shorter than a corresponding physical size of a laser beam spot used to write the image on a Xerographic photoreceptor. The laser driver may be modified to drive a light emitting element with a boost current profile that includes an overshoot above a steady state current at a rising edge. The overshoot results in a light intensity time profile that has an increased area for a subpixel.

Abstract: Disclosed is a printing apparatus and method to correct for image non-uniformities. The printing apparatus comprises a photoreceptor (P/R) belt charging device positioned to charge the P/R belt after an image is transferred to a media sheet. Subsequently, an image sensing device scans the P/R belt residual image or patches to detect image non-uniformities.

Abstract: Techniques are disclosed that enable fine features such as serifs and narrow strokes of texts to be produced by xerographic devices, for example. The fine features may be generated by subpixels which are produced when a pulse width used to image a pixel is shorter than a corresponding physical size of a laser beam spot used to write the image on a Xerographic photoreceptor. The laser driver may be modified to drive a light emitting element with a boost current profile that includes an overshoot above a steady state current at a rising edge. The overshoot results in a light intensity time profile that has an increased area for a subpixel.

Abstract: Disclosed is a printing apparatus and method to correct for image non-uniformities. The printing apparatus comprises a photoreceptor (P/R) belt charging device positioned to charge the P/R belt after an image is transferred to a media sheet. Subsequently, an image sensing device scans the P/R belt residual image or patches to detect image non-uniformities.

Abstract: Tone reproduction curves for calibrating a marking system are obtained using a test pattern with a plurality of patches, preferably a plurality of first test patches extending in a first direction and at least one second test patch extending in a second direction crossing the first direction. Reflectance values are obtained from the first and second test patches. A set of gray balanced tone reproduction curves are obtained based on the reflectance values of the first test patches, and a set of spatial gray balanced tone reproduction curves are obtained based on the reflectance values of the second test patches.

Abstract: A system changes the setpoint of a digital reprographic system in response to the local image content by utilizing tag data that contains information identifying the image content type of a corresponding image data pixel. The system modifies the reproduction characteristics of the output to accommodate the diverse image content types by simultaneously controlling the overall tone reproduction curve of the system on a pixel-by-pixel basis.

Abstract: Various exemplary embodiments include an electrostatographic printing apparatus and a method of correcting one or more associated uniformity profiles. In various exemplary embodiments the apparatus includes first and second actuators. In various exemplary embodiments the method includes measuring an image and generating at least one corresponding TRC, generating a charge profile, subtracting a reference patch density from a patch value to obtain a difference profile, converting the difference profile to a ROS intensity profile and an LED intensity profile, and iteratively repeating the steps of measuring, generating, subtracting and converting until within an acceptable range.

Abstract: A method and system compensates for streak defects in an image formed using a raster output scanning device. A reflectance profile is generated from an image generated by the raster output scanning device. Thereafter, a difference profile is determined. The difference profile is determined based upon the generated reflectance profile and a uniform profile. A compensation profile is generated based on the determined difference profile. The compensation profile represents a change in an intensity profile for the raster output scanning device.

Abstract: Methods for automated uniformity assessment and modification of image non-uniformities using an image measurement device capable of determining image reflectance and/or transmitter as a function of position, such as a spectrophotometer, a calorimeter, and/or a densitometer. One or more of these devices scan an image on a substrate, such as a sheet, thereby generating data representing image characteristics, such as, for example, image non-uniformity. The sheet may contain a reference/test pattern including one column, strip or patch intended to have a uniform density. This data generated by the device after the scan of the substrate is analyzed with signal processing algorithms for image characteristics assessment, including image spatial uniformity and compared to reference image characteristics including image spatial uniformity. An image modification profile may be generated to be applied to a marking system to thereby alter subsequent image data and improve image spatial uniformity of the marking system.

Abstract: A diagnostic routine for determining the cause of color non-uniformity in a full color image forming device, by selecting a substation of one print station and using it in combination with a substation from another print station, while functionally omitting the intervening substations. The charge setting on the charge substation is adjusted to compensate for the increased distance between the charge substation, and the developing substation in this method.

Abstract: Tone reproduction curves for calibrating a marking system are obtained using a test pattern with a plurality of patches, preferably a plurality of first test patches extending in a first direction and at least one second test patch extending in a second direction crossing the first direction. Reflectance values are obtained from the first and second test patches. A set of gray balanced tone reproduction curves are obtained based on the reflectance values of the first test patches, and a set of spatial gray balanced tone reproduction curves are obtained based on the reflectance values of the second test patches.