# US 2021/0276322 A1 · Systems and methods for printer density compensation and stability > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0276322 A1 - Document ID: US20210276322A1 - Status: Published application - Kind: A1 - Application number: 16/813,054 - Filed: 2020-03-09 - Published: 2021-09-09 - Earliest claimed: 2020-03-09 - Assignees: Global Graphics Software Limited - Applicants: Global Graphics Software Limited - Inventors: Daniel Hall; James Fox - Web page: https://patentgrep.com/patent/US20210276322A1 ## CPC - B41J 2/04508: {aiming at correcting other parameters} - G06K 15/027: {Test patterns and calibration (arrangements for controlling or analysing printing mechanisms of typewriters or selective printing units B41J29/393 takes precedence; colour correction using test pattern analysis in general H04N1/6033)} - B41J 2/04586: {controlling heads of a type not covered by groups B41J2/04575 - B41J2/04585, or of an undefined type} - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS - G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS ## Abstract A method for adjusting a modifiable printing parameter of each of a plurality of printing elements of a printing device includes printing a plurality of test charts for each of the printing elements at different values of the modifiable printing parameter; measuring a variance of a printing density for each of the test charts; analyzing the measured variances for each of the printing elements; individually selecting a value of the modifiable printing parameter for each of the printing elements based on the analysis; and applying the selected value of the modifiable printing parameter for each of the printing elements to the printing device. Software density compensation can be applied to further reduce the variance of the printing density. ## Claims ### Claim 1 A method for adjusting a modifiable printing parameter of each of a plurality of printing elements of a printing device, the method comprising: printing a plurality of test charts for each of the printing elements at different values of the modifiable printing parameter; measuring a variance of a printing density for each of the test charts; analyzing the measured variances for each of the printing elements; individually selecting a value of the modifiable printing parameter for each of the printing elements based on the analysis; and applying the selected value of the modifiable printing parameter for each of the printing elements to the printing device. ### Claim 2 (depends on 1) The method of claim 1, further comprising applying software density compensation to further reduce the variance of the printing density. ### Claim 3 (depends on 1) The method of claim 1, wherein printing the plurality of test charts comprises printing the test charts for a plurality of colors for each of the printing elements. ### Claim 4 (depends on 1) The method of claim 1, wherein printing the plurality of test charts comprises printing the test charts for a plurality of different input density levels for each of the printing elements. ### Claim 5 (depends on 1) The method of claim 1, wherein printing the plurality of test charts comprises printing the test charts at a plurality of different times, separated by at least 15 minutes, for each of the printing elements. ### Claim 6 (depends on 1) The method of claim 1, wherein the analyzing comprises weighting the measured variance by either a) the input density value associated with that measured variance or b) a time at which the associated test chart was printed. ### Claim 7 A system for adjusting a modifiable printing parameter of each of a plurality of printing elements of a printing device, the system comprising: one or more memory devices that store instructions; a parameter adjustment engine stored in the one or more memory devices, the parameter adjustment engine configured to; and one or more processor devices that execute the stored instructions to perform actions for operation of the parameter adjustment engine, the actions comprising: measuring a variance of a printing density for a plurality of test charts printed for each of the printing elements at different values of the modifiable printing parameter; analyzing the measured variances for each of the printing elements; individually selecting a value of the modifiable printing parameter for each of the printing elements based on the analysis; and applying the selected value of the modifiable printing parameter for each of the printing elements to the printing device. ### Claim 8 (depends on 7) The system of claim 7, wherein the actions further comprise applying software density compensation to further reduce the variance of the printing density. ### Claim 9 (depends on 7) The system of claim 7, wherein the actions further comprise printing the plurality of test charts. ### Claim 10 (depends on 9) The system of claim 9, wherein printing the plurality of test charts comprises printing the test charts for a plurality of colors for each of the printing elements. ### Claim 11 (depends on 9) The system of claim 9, wherein printing the plurality of test charts comprises printing the test charts for a plurality of different input density levels for each of the printing elements. ### Claim 12 (depends on 9) The system of claim 9, wherein printing the plurality of test charts comprises printing the test charts at a plurality of different times, separated by at least 15 minutes, for each of the printing elements. ### Claim 13 (depends on 7) The system of claim 7, wherein the analyzing comprises weighting the measured variance by either a) the input density value associated with that measured variance or b) a time at which the associated test chart was printed. ### Claim 14 A non-transitory computer-readable medium having stored thereon instructions for execution by a processor, the instructions comprising: measuring a variance of a printing density for a plurality of test charts printed for each of the printing elements at different values of the modifiable printing parameter; analyzing the measured variances for each of the printing elements; individually selecting a value of the modifiable printing parameter for each of the printing elements based on the analysis; and applying the selected value of the modifiable printing parameter for each of the printing elements to the printing device. ### Claim 15 (depends on 14) The non-transitory computer-readable medium of claim 14, further comprising applying software density compensation to further reduce the variance of the printing density. ### Claim 16 (depends on 14) The non-transitory computer-readable medium of claim 14, wherein the instructions further comprise printing the plurality of test charts. ### Claim 17 (depends on 16) The non-transitory computer-readable medium of claim 16, wherein printing the plurality of test charts comprises printing the test charts for a plurality of colors for each of the printing elements. ### Claim 18 (depends on 16) The non-transitory computer-readable medium of claim 16, wherein printing the plurality of test charts comprises printing the test charts for a plurality of different input density levels for each of the printing elements. ### Claim 19 (depends on 16) The non-transitory computer-readable medium of claim 16, wherein printing the plurality of test charts comprises printing the test charts at a plurality of different times, separated by at least 15 minutes, for each of the printing elements. ### Claim 20 (depends on 14) The non-transitory computer-readable medium of claim 14, wherein the analyzing comprises weighting the measured variance by either a) the input density value associated with that measured variance or b) a time at which the associated test chart was printed.