Abstract: A method for recycling ink in an inkjet printer includes combining purged inks having two or more colors with black ink to form a mixed ink. The printer identifies an optical characteristic of the mixed ink and compares it to the optical characteristic for black ink. A controller for the printer adjusts the operation of the printer to form ink images having an optical characteristic that is closer to black ink than ink images formed with the mixed ink alone.

Abstract: A method for recycling ink in an inkjet printer includes combining purged inks having two or more colors with black ink to form a mixed ink. The printer identifies an optical characteristic of the mixed ink and compares it to the optical characteristic for black ink. A controller for the printer adjusts the operation of the printer to form ink images having an optical characteristic that is closer to black ink than ink images formed with the mixed ink alone.

Abstract: Engine response curves (RCs) can be used for streak compensation for printed documents. A feedback control paradigm can be included to effect RC compensation. Singular Value Decomposition (SVD) can be used to represent each RC in the collection of spatial RC data as a linear combination of basis vectors. RCs are approximated by selecting the first few basis vectors, the approximation aiding in noise rejection and reducing computation in the controller by reducing dimensionality of the RC data from gray levels to the number of SVD bases selected. An optimal subset of RCs is selectable from the set of approximated RCs by clustering the SVD weights, the clustered SVD weights producing TRCs that span all engine response RCs generated by a printer. Compensation RCs are constructible using reduced number of bases and clustered SVD weights.

Abstract: A method for recycling ink in an inkjet printer includes combining purged inks having two or more colors with black ink to form a mixed ink. The printer identifies an optical characteristic of the mixed ink and compares it to the optical characteristic for black ink. A controller for the printer adjusts the operation of the printer to form ink images having an optical characteristic that is closer to black ink than ink images formed with the mixed ink alone.

Abstract: A method for recycling ink in an inkjet printer includes combining purged inks having two or more colors with black ink to form a mixed ink. The printer identifies an optical characteristic of the mixed ink and compares it to the optical characteristic for black ink. A controller for the printer adjusts the operation of the printer to form ink images having an optical characteristic that is closer to black ink than ink images formed with the mixed ink alone.

Abstract: Engine response curves (RCs) can be used for streak compensation for printed documents. A feedback control paradigm can be included to effect RC compensation. Singular Value Decomposition (SVD) can be used to represent each RC in the collection of spatial RC data as a linear combination of basis vectors. RCs are approximated by selecting the first few basis vectors, the approximation aiding in noise rejection and reducing computation in the controller by reducing dimensionality of the RC data from gray levels to the number of SVD bases selected. An optimal subset of RCs is selectable from the set of approximated RCs by clustering the SVD weights, the clustered SVD weights producing TRCs that span all engine response RCs generated by a printer. Compensation RCs are constructible using reduced number of bases and clustered SVD weights.

Abstract: A method evaluates image quality in an ink printing system and generates data values for altering the operation of the ink printing system. The method includes generating an ink image on an ink image receiving member that corresponds to a digital image stored in the ink printing system, generating a scanned image signal corresponding to the ink image, generating firing signal waveform adjustments and image data adjustments with reference to the scanned image signal corresponding to the ink image, and operating a printhead in an ink imaging system with reference to the firing signal waveform adjustments and the image data adjustments.

Abstract: A method of operating a printhead of an imaging device includes actuating a plurality of ink jets of the printhead to emit drops of ink onto an image receiving surface in accordance with a test pattern. The test pattern includes full pixel density areas and half pixel density areas that alternate in a process direction. Distances in a process direction between drops of the full pixel density areas and drops of the half pixel density areas in transition regions of the test pattern are then measured. The measured process direction distances are then correlated to a graininess level for the printhead.

Abstract: What is disclosed is a novel system and method for reducing process color banding due to printhead non-uniformities in a direct marking device. In one example, a first measurement of a printhead spatial non-uniformity is obtained along a first line in a color space which produces a spatial uniformity when a target primary color is printed alone. A first spatial tone reproduction curve is generated. A second measurement of the printhead spatial non-uniformity is obtained along a second line in color space in a coverage area of a process color which maximally changes a halftone structure of the target primary color. A second spatial TRC is generated. The first and second spatial TRCs are combined using a weighted average which balances the primary and process colors. A modified spatial TRC is generated. The printhead is adjusted at a location of the target primary color according to the modified spatial TRC.

Abstract: A method of operating a printhead of an imaging device includes actuating a plurality of ink jets of the printhead to emit drops of ink onto an image receiving surface in accordance with a test pattern. The test pattern includes full pixel density areas and half pixel density areas that alternate in a process direction. Distances in a process direction between drops of the full pixel density areas and drops of the half pixel density areas in transition regions of the test pattern are then measured. The measured process direction distances are then correlated to a graininess level for the printhead.

Abstract: Engine response curves (RCs) can be used for streak compensation for printed documents. A feedback control paradigm can be included to effect RC compensation. Singular Value Decomposition (SVD) can be used to represent each RC in the collection of spatial RC data as a linear combination of basis vectors. RCs are approximated by selecting the first few basis vectors, the approximation aiding in noise rejection and reducing computation in the controller by reducing dimensionality of the RC data from gray levels to the number of SVD bases selected. An optimal subset of RCs is selectable from the set of approximated RCs by clustering the SVD weights, the clustered SVD weights producing TRCs that span all engine response RCs generated by a printer. Compensation RCs are constructible using reduced number of bases and clustered SVD weights.

Abstract: A method evaluates image quality in an ink printing system and generates data values for altering the operation of the ink printing system. The method includes generating an ink image on an ink image receiving member that corresponds to a digital image stored in the ink printing system, generating a scanned image signal corresponding to the ink image, generating firing signal waveform adjustments and image data adjustments with reference to the scanned image signal corresponding to the ink image, and operating a printhead in an ink imaging system with reference to the firing signal waveform adjustments and the image data adjustments.

Abstract: What is disclosed is a novel system and method for reducing process color banding due to printhead non-uniformities in a direct marking device. In one example, a first measurement of a printhead spatial non-uniformity is obtained along a first line in a color space which produces a spatial uniformity when a target primary color is printed alone. A first spatial tone reproduction curve is generated. A second measurement of the printhead spatial non-uniformity is obtained along a second line in color space in a coverage area of a process color which maximally changes a halftone structure of the target primary color. A second spatial TRC is generated. The first and second spatial TRCs are combined using a weighted average which balances the primary and process colors. A modified spatial TRC is generated. The printhead is adjusted at a location of the target primary color according to the modified spatial TRC.

Abstract: A registration system for image data in a binary image path includes a registration parameter source, such as a preprogrammed memory or a dynamic device, which provides registration parameters to correct for registration errors from a predetermined reference likely or predicted to occur during image output. A warping processor is in data communication with the registration parameter source which applies a selected registration parameter to an element of the image data resulting in a warped data element, minimizing the effects of the registration error. The system optionally includes an image reducing device which receives groups of high addressable binary image data and converts them to a single pixel. The pixel is then provided to the warping processor. The warping processor applies the selected registration parameter, either static or dynamically selected, from the registration parameter source to the averaged single pixel producing a warped data element.

Abstract: An apparatus and method for adjusting color and gray balance in a color printer, wherein a multicolored output sheet including a set of printer color balance adjustment instructions for performing color balance adjustments processor is produced by the print engine. A processor provides a color balance judging indicator, from to a scanned test pattern sheet in the case of a copier or from a memory electronically storing a test image. A controller is used to for transmit the set of printer color and gray balance adjustments to the processor.

Abstract: An apparatus for transferring a developed image from a photoconductive surface to a copy sheet in a transfer zone is disclosed. The apparatus includes a mechanism for directing a flow of gas onto the copy sheet in the transfer zone to urge the copy sheet toward the developed image on the photoconductive surface so as to enhance contact between the copy sheet and the developed image in the transfer zone. The apparatus further includes a mechanism for charging the copy sheet in the transfer zone, after the gas directing mechanism directs the flow of gas onto the copy sheet, to attract the developed image from the photoconductive surface to the copy sheet. Also disclosed is a method of transferring a developed image from a photoconductive surface to a copy sheet in a transfer zone.