# US 9,434,176 B1 · Vector compensation for inoperative ink-jets in composite colors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,434,176 B1 - Document ID: US9434176B1 - Status: Granted - Kind: B1 - Application number: 14/754,272 - Filed: 2015-06-29 - Granted: 2016-09-06 - Earliest claimed: 2015-06-29 - Assignees: Xerox Corporation - Applicants: Xerox Corporation - Inventors: Stephen Michael Kroon - Web page: https://patentgrep.com/patent/US9434176B1 ## CPC - B41J 2/2103: {Features not dealing with the colouring process per se, e.g. construction of printers or heads, driving circuit adaptations} - B41J 2/2139: {Compensation for malfunctioning nozzles creating dot place or dot size errors (generating single droplets or particles on demand by pressure, e.g. electromechanical transducers B41J2/045)} - B41J 2/2146: {for line print heads} - H04N 1/6075: {Corrections to the hue} - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract The system and methods described maintain composite color print integrity of an inoperative ink-jet. The methods may include a computing device and a printer to obtain the print job and reconstruct a pixel bitmap. The methods may also include a sensor configured to generate output signals associated with the individual ink-jets located in the print-head to indicate inoperative ink-jets and help compensate for those ink-jets. ## Claims ### Claim 1 A system for maintaining colorimetry and hue in printed composite colors comprising: a printer configured to obtain a bitmap indicating a first color-plane and a first contone compensation for a first pixel; a sensor configured to generate output signals indicating a first inoperative color-plane; and a controller configured to control a second adjacent color-plane and contone to compensate the first inoperative color-plane and configured to compensate for at least one operative color-plane at the first pixel; wherein the controller controls the second adjacent color-plane to compensate the first inoperative color-plane by treating all operative and inoperative color-planes in the adjacent raster column as inoperative. ### Claim 2 (depends on 1) The system of claim 1, further comprising an optical sensor to generate output signals to the controller related to the hue of the composite color, wherein the controller is configured to evaluate or modify the second adjacent color-plane compensation. ### Claim 3 (depends on 1) The system of claim 1, wherein the controller determines a rate of change in the levels of unprintable ink remaining in inoperative ink-jets or a rate of change in the levels of printable ink in operative ink-jets to determine inoperative ink-jets. ### Claim 4 (depends on 1) The system of claim 1, wherein the printer prints at full speed. ### Claim 5 (depends on 1) The system of claim 1, wherein the controller is configured to control the second adjacent color-plane to deflect ink into the adjacent raster column to compensate the first inoperative color-plane. ### Claim 6 (depends on 1) The system of claim 1, wherein the controller is configured to control the second adjacent color-plane contone to increase a volume of ink in order to compensate the first inoperative color-plane. ### Claim 7 A method for maintaining colorimetry and hue in printed composite colors comprising: obtaining a bitmap indicating a first color-plane and a first contone compensation for a first pixel; generating output signals indicating a first inoperative color-plane; and controlling a second adjacent color-plane and contone to compensate the first inoperative color-plane and configured to compensate for at least one operative color-plane at the first pixel; wherein controlling the second adjacent color-plane compensates the first inoperative color-plane by treating all operative and inoperative color-planes in the adjacent raster column as inoperative. ### Claim 8 (depends on 7) The method of claim 7, wherein the controller determines a rate of change in the levels of unprintable ink remaining in inoperative ink-jets or a rate of change in the levels of printable ink in operative ink-jets to determine which ink-jets are inoperative. ### Claim 9 (depends on 7) The method of claim 7, further comprising: evaluating IJC implementation by reviewing levels of remaining unprintable ink from inoperative ink-jets compared to ink remaining in working rasters processed as missing by IJC. ### Claim 10 (depends on 9) The method of claim 9, wherein successful application of IJC renders the bitmap and allows the printer to print at full speed. ### Claim 11 (depends on 7) The method of claim 7, wherein the second adjacent color-plane is controlled to deflect ink into the adjacent raster column to compensate the inoperative first color-plane. ### Claim 12 A method for maintaining colorimetry and hue of printed composite colors in a halftone printing process, the method comprising: obtaining a bitmap indicating a first color-plane and a first pre-halftone compensation for a first pixel; generating output signals indicating a first inoperative color-plane; and controlling a second adjacent color-plane and post-halftone to compensate the first inoperative color-plane and configured to compensate for at least one operative color-plane at the first pixel; wherein controlling the second adjacent color-plane compensates the first inoperative color-plane by treating all operative and inoperative color-planes in the adjacent raster column as inoperative. ### Claim 13 (depends on 12) The method of operating ink-jets in a printer of claim 12, further comprising: evaluating the post-halftone IJC by reviewing levels of remaining ink unprintable due to inoperative ink-jets. ### Claim 14 (depends on 12) The method of claim 12, wherein if the application of the post-halftone IJC is successful, the printer prints the print job at full speed. ### Claim 15 (depends on 12) The method of claim 12, wherein if the application of the post-halftone IJC is not successful, the printer prints the print job at reduced speed. ### Claim 16 (depends on 12) The method of claim 12, further including applying the pre-halftone IJC to swaths corresponding to missing raster swaths in all other color-planes in the composite color to be printed in the columns identified as missing due to the inoperative ink-jet. ### Claim 17 (depends on 12) The method of claim 12, further including applying the post-halftone IJC to swaths corresponding to missing raster swaths in all other color-planes in the composite color to be printed in the columns identified as missing due to the inoperative ink-jet.