Abstract: Methods for operating a toner printer are provided. In one method a toner image is printed according to first printing instructions. An amount of toner in a target area of the toner image is determined and second printing instructions are generated causing the toner printer to print at least one subsequent toner image based upon the determined amount of first toner.

Abstract: Toner printers are provided. In one printer a toner image is printed according to first printing instructions. An amount of toner in a target area of the toner image is determined and second printing instructions are generated causing the toner printer to print at least one subsequent toner image based upon the determined amount of first toner.

Abstract: Toner sensor modules are provided. In one aspect, a toner sensor module has a first light source emitting a first light, a first light sensor that generates a sensed light signal that is indicative of a sensed light, and a frame. The frame positions the light source to illuminate a target area from a first side a plane that is normal to the target area so that illuminated portions of any toner particles at the target area direct a reflected a portion of the first light into the first side and positioning the first light sensor on the first side of the plane to which toner particles at the target area direct the reflected portion of the first light.

Abstract: Non-uniformity of a rotatable electrophotographic imaging component is compensated. The component has an intentional periodic variation that produces density variations in a test target. The angular position on the component of the intentional variation is correlated with the amount of an unintentional variation at several points to produce a non-uniformity map. An image signal with multiple regions of data is received. For each region, the angular position of the intentional variation in that region is determined, and the non-uniformity map is used to determine the correction required for the unintentional variation. The image data in the region are adjusted to compensate, and corresponding toner is deposited.

Abstract: Methods for operating a toner printer are provided. In one method a toner image is printed according to first printing instructions. An amount of toner in a target area of the toner image is determined and second printing instructions are generated causing the toner printer to print at least one subsequent toner image based upon the determined amount of first toner.

Abstract: Toner sensor modules are provided. In one aspect, a toner sensor module has a first light source emitting a first light, a first light sensor that generates a sensed light signal that is indicative of a sensed light, and a frame. The frame positions the light source to illuminate a target area from a first side a plane that is normal to the target area so that illuminated portions of any toner particles at the target area direct a reflected a portion of the first light into the first side and positioning the first light sensor on the first side of the plane to which toner particles at the target area direct the reflected portion of the first light.

Abstract: Toner printers are provided. In one printer a toner image is printed according to first printing instructions. An amount of toner in a target area of the toner image is determined and second printing instructions are generated causing the toner printer to print at least one subsequent toner image based upon the determined amount of first toner.

Abstract: Methods for determining an amount of toner in a target area are provided. In one method, the target area is illuminated with a first light from a first illumination position that is on a first side of a plane that is normal to the target area so that any toner particles in the target area direct a reflected portion of the first light to the first side and a light is sensed at a surface at a sensing position on the first side of the plane to which toner particles at the target area direct the reflected portion of the first light and a sensed light signal is generated that is indicative of the sensed light.

Abstract: A method is provided of determining the cause of artifacts in images produced by an electrophotographic (EP) printer. A reference image is printed and artifacts in it are detected. After printing normal images, a test image is printed and artifacts in it are detected. If a detected artifact in the test image does not correspond to a detected artifact in the reference image, a characteristic frequency spectrum of the artifact in the test image is determined. Run-out on rotatable imaging components is measured, and a characteristic frequency spectrum of each is determined. The test image spectrum is compared to each component spectrum to identify which component is causing the artifact.

Abstract: A method is provided of determining the cause of artifacts in images produced by an electrophotographic (EP) printer. A reference image is printed and artifacts in it are detected. After printing normal images, a test image is printed and artifacts in it are detected. If a detected artifact in the test image does not correspond to a detected artifact in the reference image, a characteristic frequency spectrum of the artifact in the test image is determined. Run-out on rotatable imaging components is measured, and a characteristic frequency spectrum of each is determined. The test image spectrum is compared to each component spectrum to identify which component is causing the artifact.

Abstract: Non-uniformity of a rotatable electrophotographic imaging component is compensated. The component has an intentional periodic variation that produces density variations in a test target. The angular position on the component of the intentional variation is correlated with the amount of an unintentional variation at several points to produce a non-uniformity map. An image signal with multiple regions of data is received. For each region, the angular position of the intentional variation in that region is determined, and the non-uniformity map is used to determine the correction required for the unintentional variation. The image data in the region are adjusted to compensate, and corresponding toner is deposited.

Abstract: A method of development control by storing a reference tone reproduction curve and sensing a relatively small segment of an arbitrary image on an imaging surface. The relatively small segment of the arbitrary image on the imaging surface is then converted into suitable density values, such as background, solid area, and halftone and a control responds to the density values to adjust the machine operation for print quality correction.