# US 8,740,343 B2 · Image correction system and image correction method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,740,343 B2 - Document ID: US8740343B2 - Status: Granted - Kind: B2 - Application number: 13/931,774 - Filed: 2013-06-28 - Published: 2013-11-07 - Granted: 2014-06-03 - Earliest claimed: 2009-02-13 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Yoshinori Kawai - Web page: https://patentgrep.com/patent/US8740343B2 ## CPC - B41J 29/393: Devices for controlling or analysing the entire machine {; Controlling or analysing mechanical parameters involving printing of test patterns} - B41J 2/2103: {Features not dealing with the colouring process per se, e.g. construction of printers or heads, driving circuit adaptations} - H04N 1/482: {using the same detector device sequentially for different colour components} - H04N 1/6033: {using test pattern analysis (H04N1/6055 takes precedence)} - 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 Every time density correction information corresponding to a colorimetric value of a patch is acquired, the time when the density correction information is acquired and the type of a printing medium on which the patch is printed are accumulated in association in a memory. The type of a medium for printing is specified by a user; density correction information acquired at the most up-to-date time for each chromatic color ink available for the medium of that type is read from the memory; it is determined whether or not the most up-to-date time when the density correction information is acquired for each of the chromatic color inks available for the specified medium is the same time; if the most up-to-date times are the same, density correction is performed on image data, using a correction table that corresponds to the density correction information acquired at the most up-to-date time. ## Claims ### Claim 1 An image processing apparatus for printing an image on a printing medium with a printhead which is able to discharge a plurality of inks having different colors, the apparatus comprising: a controlling unit configured to cause the printhead to print patches on the printing medium in a predetermined printing mode, wherein the predetermined printing mode uses a first combination of inks, and wherein the first combination of inks includes a part of the plurality of inks and does not include an ink other than the part of the plurality of inks; an acquiring unit configured to acquire density correction information of each ink of the first combination of inks based on measurement results of the patches; and a storing unit configured to store the density correction information of each of the plurality of inks in a memory, wherein the storing unit stores the density correction information acquired by said acquiring unit as latest density correction information of each of the first combination of inks, wherein at least a part of the density correction information acquired by the acquiring unit is used for correcting image data to be printed in a printing mode using a second combination of inks different from the first combination of inks. ### Claim 2 (depends on 1) The apparatus according to claim 1, further comprising a correcting unit configured to correct the image data by using latest density correction information of each of the second combination of inks. ### Claim 3 (depends on 2) The apparatus according to claim 2, wherein the first combination of inks includes a second ink and does not include a first ink, and the second combination of inks includes the first ink and the second ink, and wherein the correcting unit corrects the image data corresponding to the first ink and the image data corresponding to the second ink by using the latest density correction information of the first ink and the latest density correction information of the second ink, even though a timing of storing as the latest density correction information of the first ink and a timing of storing as the latest density correction information of the second ink differ from each other. ### Claim 4 (depends on 3) The apparatus according to claim 3, wherein, in a case where the latest density correction information of the first ink is acquired by the acquiring unit at a first time and the latest density correction information of the second ink is acquired by the acquiring unit at a second time which is later than the first time, and the image is printed by using the second combination of inks at a third time which is later than the second time, the correcting unit corrects the image data corresponding to the first ink by using the latest density correction information acquired at the first time and corrects the image data corresponding to the second ink by using the latest density correction information acquired at the second time. ### Claim 5 (depends on 3) The apparatus according to claim 3, wherein the controlling unit causes the print head to print an image on a first printing medium by using the first combination of inks, and the controlling unit causes the print head to print an image on a second printing medium which is a different type from the first printing medium by using the second combination of inks. ### Claim 6 (depends on 3) The apparatus according to claim 3, wherein the first ink is an achromatic ink and the second ink is a chromatic ink. ### Claim 7 (depends on 6) The apparatus according to claim 6, wherein, based on measurement results of patches printed by using a third combination of inks on a third printing medium which is different from the first and second printing mediums, wherein the third combination of inks does not include the first ink and includes the second ink and a third ink which is a different achromatic ink from the first ink, the acquiring unit acquires the density correction information of the second ink and the density correction information of the third ink, and the storing unit stores the density correction information of the second ink and the density correction information of the third ink in the memory. ### Claim 8 (depends on 1) The apparatus according to claim 1, wherein the density correction information indicates a rank of amount of ink droplet discharged by the print head based on measurement results of the patches. ### Claim 9 (depends on 1) The apparatus according to claim 1, wherein, in a case where the storing unit stores the density correction information acquired by said acquiring unit as the latest density correction information of each of the first combination of inks, the density correction information of an ink other than the first combination of inks is not changed to latest density correction information. ### Claim 10 (depends on 1) The apparatus according to claim 1, wherein the patches include a patch which is printed by one ink of the first combination of inks. ### Claim 11 An image processing method for an image processing apparatus for printing an image on a printing medium with a printhead which is able to discharge a plurality of inks having different colors, the method comprising: causing the printhead to print patches on the printing medium in a predetermined printing mode, wherein the predetermined printing mode uses a first combination of inks, and wherein the first combination of inks includes a part of the plurality of inks and does not include an ink other than the part of the plurality of inks; acquiring density correction information of each ink of the first combination of inks based on measurement results of the patches; and storing the density correction information of each of the plurality of inks in a memory, wherein the acquired density correction information is stored as latest density correction information of each of the first combination of inks, wherein at least a part of the acquired density correction information is used for correcting image data to be printed in a printing mode using a second combination of inks different from the first combination of inks.