Abstract: Reflex writing is a group of algorithms developed to maintain color registration in xerographic systems using multiple imagers, in which sequential color separations are written based on events in the spatial domain. The imaging system includes a raster output scanner imager for the black station and a light emitting diode bar for the color station. A simulated machine clock signal is generated based on a running average of a plurality of actual machine clock periods determined from pulses received from a photoreceptor module drive roll encoder. For each black scanline written the distance the belt travels is tracked using the simulated machine clock signal, and when the black latent image scanline has traveled the known distance between the two imagers, the light emitting diode scanline is written registered with respect to the raster output scanner scanline.

Abstract: A system and method for spatially matching the output of two imaging stations in an electro-photographic device by using a second order polynomial curve and a third order polynomial curve to approximate the non-linearity errors between the two imaging stations and using the second order polynomial curve and the third order polynomial curve to modify the frequency of a pixel clock.

Abstract: Reflex writing is a group of algorithms developed to maintain color registration in xerographic systems using multiple imagers. Unlike conventional imaging, in which the individual color separations are imaged based on events in a time domain, in a reflex write implementation sequential color separations are written based on events in the spatial domain. Once the initial color separation is written, the distance that color separation travels is tracked until the color separation is under the next imaging station, where the next color separation is written properly registered with respect to the existing color separation. The imaging system includes a raster output scanner imager for the black station and a light emitting diode bar for the color station.

Abstract: A system and method for spatially matching the output of two imaging stations in an electro-photographic device by using a second order polynomial curve and a third order polynomial curve to approximate the non-linearity errors between the two imaging stations and using the second order polynomial curve and the third order polynomial curve to modify the frequency of a pixel clock.

Abstract: There is provided a method for use with a printing machine having a movable imaging member and a projecting system for modulating a beam and projecting an image into the movable imaging member. The printing machine further includes a developer for application of developer material to the image projected onto the movable imaging member for transfer of the image to a print media sheet.

Abstract: A method and apparatus for the control of darkness/lightness in a digital image rendered by a printing system. The technique preferably employs templates to selectively apply different amounts of darkening (lightening) to borders of structures detected within the image dependent upon the need for darkening (lightening).

Abstract: A system for providing an output from a digital printing apparatus which is of higher resolution than the native resolution of the original image data. For a given center pixel area, image data corresponding to pixel areas generally neighboring the center pixel area are attempted to be matched to various templates which are consistent with curved lines in which resolution enhancement of the center pixel would be desirable. In a second stage of template matching, a second set of image data, corresponding to pixel areas further away from the center pixel than the first set of pixel areas, is also attempted to be matched to templates. The second stage of template matching helps to avoid resolution enhancement of image data which is related to a halftone image.

Abstract: A lead edge lightening circuit which will lighten a scan line based on a seven by seven pixel area surrounding the current pixel. The area is divided into four sub-areas, each of four by four pixels, and each having the current pixel at one corner. Each sub-area is summed and compared to a threshold number. If the threshold number is equalled or exceeded by at least one of the four sums, an overlay bit, which can be white or black, is output. The current pixel is replaced by a white pixel if a white pixel has been output, otherwise the current pixel remains unchanged.