# US 2013/0155137 A1 · Method and System for Split Head Drop Size Printing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0155137 A1 - Document ID: US20130155137A1 - Status: Published application - Kind: A1 - Application number: 13/329,892 - Filed: 2011-12-19 - Published: 2013-06-20 - Earliest claimed: 2011-12-19 - Assignees: Xerox Corporation - Inventors: David A. Mantell; Jeffrey J. Folkins - Web page: https://patentgrep.com/patent/US20130155137A1 ## CPC - B41J 2/2128: {by means of energy modulation (control methods or devices therefor, e.g. driver circuits or control circuits B41J2/04501)} - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS ## Abstract A method for operating an inkjet printer to form images that include both high density and low density segments has been developed. The method includes operating one printhead to eject ink drops with a large size to form high density segments of the image, and operating a second printhead to eject ink drops with a small size to form low density segments of the image. The large ink drops provide high coverage in the high density segments, and the small ink drops provide improved image quality in the low density segments of the image. ## Claims ### Claim 1 A method of printing images in an inkjet printer comprising: receiving image data for a color separation; storing a portion of the color separation image data in a first memory map used to generate electrical signals for operating at least one printhead that is configured to eject ink drops of a first color and first ink drop mass; storing a remaining portion of the color separation image data in a second memory map used to generate electrical signals for operating at least one other printhead that is configured to eject ink drops of the first color and second ink drop mass, the second ink drop mass being greater than the first ink drop mass; generating a first plurality of electrical signals for operating the at least one printhead with reference to the first memory map for the at least one printhead; and generating a second plurality of electrical signals for operating the at least one other printhead with reference to the second memory map for the at least one other printhead. ### Claim 2 (depends on 1) The method of claim 1 wherein the at least one printhead and the at least one other printhead are interleaved in a cross-process direction across the image receiving member. ### Claim 3 (depends on 2) The method of claim 2 wherein the at least one printhead and the at least one other printhead have a same resolution in the cross-process direction. ### Claim 4 (depends on 3) The method of claim 3 further comprising: timing operation of the at least one printhead and the at least one other printhead to enable ink drops from the at least one printhead and the at least one other printhead to form a line in the cross-process direction across an image receiving member at a resolution that is twice the same resolution of the at least one printhead and the at least one other printhead. ### Claim 5 (depends on 3) The method of claim 3 further comprising: generating the first plurality of electrical signals and the second plurality of electrical signals to operate the at least one printhead and the at least one other printhead to form a plurality of lines in the cross-process direction across an image receiving member at a resolution that is twice the same resolution of the at least one printhead and the at least one other printhead, each of the lines in the plurality of lines being separated in the process direction by a line in the cross-process direction that is formed by drops from the at least one other printhead only. ### Claim 6 (depends on 1) The method of claim 1 further comprising: sending an electrical signal parameter to a printhead controller that generates with reference to the electrical signal parameter the electrical signals for operating the at least one printhead and the at least one other printhead; and operating the at least one printhead with reference to the electrical signals generated by the printhead controller at a frequency in a process direction that is less than the frequency in the process direction at which the at least one other printhead is operated. ### Claim 7 (depends on 5) The method of claim 5 wherein the at least one printhead is operated at a frequency that is one-half the frequency at which the at least one other printhead is operated. ### Claim 8 (depends on 1) The method of claim 1 further comprising: detecting a condition for reconfiguring one of the at least one printhead and the at least one other printhead; and configuring the at least one printhead to eject ink drops having the second ink drop mass. ### Claim 9 (depends on 8) The method of claim 8 wherein the condition is detection of an end of a job. ### Claim 10 (depends on 1) The method of claim 1 further comprising: detecting a condition for reconfiguring one of the at least one printhead and the at least one other printhead; and configuring the at least one other printhead to eject ink drops having the first ink drop mass. ### Claim 11 (depends on 10) The method of claim 10 wherein the condition is detection of an end of a job. ### Claim 12 An inkjet printer comprising: a first printhead positioned in a print zone including a first plurality of inkjets, the first printhead being configured to eject ink drops of a first color and first ink drop mass; a second printhead positioned in the print zone including a second plurality of inkjets, the second printhead being configured to eject ink drops of the first color and a second ink drop mass, the second ink drop mass being greater than the first ink drop mass; a media path configured to move a print medium through the print zone in a process direction past the first printhead and the second printhead; and a controller operatively connected to the first printhead, the second printhead, and the media path, the controller being configured to: receive image data for a color separation; store a portion of the color separation image data in a first memory map used to generate electrical signals for operating the first printhead; store a remaining portion of the color separation image data in a second memory map used to generate electrical signals for operating the second printhead; generate a first plurality of electrical signals for operating the first printhead with reference to the first memory map for the first printhead; and generate a second plurality of electrical signals for operating the second printhead with reference to the second memory map for the second printhead. ### Claim 13 (depends on 12) The inkjet printer of claim 12 wherein the first printhead and the second printhead are interleaved in a cross-process direction across an image receiving member. ### Claim 14 (depends on 13) The inkjet printer of claim 13 wherein the at least one printhead and the at least one other printhead have a same resolution in the cross-process direction. ### Claim 15 (depends on 14) The inkjet printer of claim 14, the controller being further configured to: operate the first printhead and the second printhead to enable ink drops from the first printhead and the second printhead to form a line in the cross-process direction across the image receiving member at a resolution that is twice the same resolution of the at first printhead and the second printhead. ### Claim 16 (depends on 14) The inkjet printer of claim 14, the controller being further configured to: generate the first plurality of electrical signals and the second plurality of electrical signals to operate the at least one printhead and the at least one other printhead to form a plurality of lines in the cross-process direction across an image receiving member at a resolution that is twice the same resolution of the at least one printhead and the at least one other printhead and to separate the lines in the plurality of lines in the process direction by a line in the cross-process direction that is formed by drops from the second printhead only. ### Claim 17 (depends on 12) The inkjet printer of claim 12, the controller being further configured to generate electrical signal parameters; and a printhead controller operative connected to the first printhead and the second printhead, the printhead controller being configured to generate with reference to electrical signal parameters received from the controller the electrical signals for operating the first printhead and the second printhead. ### Claim 18 (depends on 17) The inkjet printer of claim 17, the printhead controller being further configured to operate the first printhead at a frequency in a process direction that is less than the frequency in the process direction at which the second printhead is operated with reference to the electrical signal parameters received from the controller. ### Claim 19 (depends on 18) The inkjet printer of claim 18 wherein the printhead controller operates the first printhead at a frequency that is one-half the frequency at which the second printhead is operated. ### Claim 20 (depends on 16) The inkjet printer of claim 16, the media path being configured to move the print medium past the first printhead and the second printhead in the process direction only once to form the line at the resolution that is twice the same resolution of the first printhead and the second printhead. ### Claim 21 (depends on 12) The inkjet printer of claim 12, the controller being further configured to detect a condition for reconfiguring one of the first printhead and the second printhead and to generate electrical signals that configure the first printhead to eject ink drops having the second ink drop mass. ### Claim 22 (depends on 21) The inkjet printer of claim 21 wherein the condition is detection of an end of a job. ### Claim 23 (depends on 12) The inkjet printer of claim 12, the controller being further configured to detect a condition for reconfiguring one of the first printhead and the second printhead and to configure the second printhead to eject ink drops having the first ink drop mass. ### Claim 24 (depends on 23) The inkjet printer of claim 23 wherein the condition is detection of an end of a job.