# US 2013/0156472 A1 · Image forming apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0156472 A1 - Document ID: US20130156472A1 - Status: Published application - Kind: A1 - Application number: 13/707,912 - Filed: 2012-12-07 - Published: 2013-06-20 - Earliest claimed: 2011-12-09 - Assignees: Canon Kabushiki Kaisha - Inventors: Shinri Watanabe - Web page: https://patentgrep.com/patent/US20130156472A1 ## CPC - G03G 13/22: Processes involving a combination of more than one step according to groups G03G13/02 - G03G13/20 (G03G13/01 takes precedence) - G03G 15/0189: {primary transfer to an intermediate transfer belt (G03G15/0184 takes precedence)} - G03G 15/5058: {using a test patch} - G03G 2215/0158: Colour registration - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An image forming apparatus includes a plurality of image forming means; transferring means for superimposingly transferring the developed images; a detector for detecting light reflected by the developed image; a position detector for detecting a position of the developed image; memory for storing for each color of the developer, information relating to a correction amount for correcting an error between a position obtained by the position detector and an actual position, a corrector for correcting the position of the developed image formed on the image bearing member by the image forming means, on the basis of positions of the developed images of the respective color detected by the position detector and information relating to the correction amount stored in the memory. ## Claims ### Claim 1 An image forming apparatus comprising: a plurality of image forming means including respective image bearing members for carrying different color developed images; transferring means for superimposingly transferring the developed images from respective image bearing members onto a recording material or an intermediary transfer member to form a developed image comprising different color developed images on the recording material or the intermediary transfer member; detecting means for detecting light which is projected to the recording material or the intermediary transfer member having the developed image and reflected thereby; position detecting means for detecting a position of the developed image formed on the recording material or the intermediary transfer member on the basis of a result of detection of said detecting means; storing means for storing beforehand, for each color of the developer, information relating to a correction amount for correcting an error between a position obtained by said position detecting means and an actual position, the error resulting from increase of an image density at a downstream end of the developed image formed on the recording material or the intermediary transfer member with respect to an advancing direction of the recording material or the intermediary transfer member; and correcting means for forming a predetermined pattern image comprising superimposed developed images of different colors and for correcting the position of the developed image formed on said image bearing member by said image forming means, on the basis of positions of the developed images of the respective color detected by said position detecting means and information relating to the correction amount stored in said storing means. ### Claim 2 (depends on 1) An apparatus according to claim 1, wherein said correcting means calculates a deviation amount between a developed image of a predetermined reference color and a developed image of another color, corrects the calculated deviation amount using the information of the correction amount, and corrects the position of the developed image formed on said image bearing member by said image forming means on the basis of the corrected deviation amount. ### Claim 3 (depends on 1) An apparatus according to claim 1, wherein said correcting means corrects the positions of the developed images of the different colors detected by said position detecting means, calculates a deviation amount between a developed image of a predetermined reference color and a developed image of the another color, and corrects the position of the developed image formed on said image bearing member by said image forming means on the basis of the calculated deviation amount. ### Claim 4 (depends on 1) An apparatus according to claim 1, wherein said correcting means corrects the position of the developed image formed to said image bearing member by said image forming means on the basis of information of the correction amount so as to reduce the deviation between the position detected by said position detecting means and the actual position, and then calculates a deviation amount between a developed image of a predetermined reference color and a developed image of the another color on the basis of the positions of the developers of the colors detected by said position detecting means when the pattern image is formed on the recording material or the intermediary transfer member, and then corrects the position of the developed image formed on said image bearing member by said image forming means, on the basis of the calculated deviation amount. ### Claim 5 (depends on 1) An apparatus according to claim 1, further comprising an ambient condition detecting means for detecting at least any of a temperature and a humidity of an operating environment, wherein said storing means further stores information of a corresponding relation between the ambient condition and the correction amount, and said correcting means detects by said ambient condition detecting means the ambient condition when the pattern image is formed on the recording material or the intermediary transfer member, and corrects the position of the developed image formed on said image bearing member by said image forming means, on the basis of information of the correction amount corresponding to the detected ambient condition. ### Claim 6 (depends on 2) An apparatus according to claim 2, further comprising an ambient condition detecting means for detecting at least any of a temperature and a humidity of an operating environment, wherein said storing means further stores information of a corresponding relation between the ambient condition and the correction amount, and said correcting means detects by said ambient condition detecting means the ambient condition when the pattern image is formed on the recording material or the intermediary transfer member, and corrects the position of the developed image formed on said image bearing member by said image forming means, on the basis of information of the correction amount corresponding to the detected ambient condition. ### Claim 7 (depends on 3) An apparatus according to claim 3, further comprising an ambient condition detecting means for detecting at least any of a temperature and a humidity of an operating environment, wherein said storing means further stores information of a corresponding relation between the ambient condition and the correction amount, and cone wherein said correcting means detects by said ambient condition detecting means the ambient condition when the pattern image is formed on the recording material or the intermediary transfer member, and corrects the position of the developed image formed on said image bearing member by said image forming means, on the basis of information of the correction amount corresponding to the detected ambient condition. ### Claim 8 (depends on 4) An apparatus according to claim 4, further comprising an ambient condition detecting means for detecting at least any of a temperature and a humidity of an operating environment, wherein said storing means further stores information of a corresponding relation between the ambient condition and the correction amount, and wherein said correcting means detects by said ambient condition detecting means the ambient condition when the pattern image is formed on the recording material or the intermediary transfer member, and corrects the position of the developed image formed on said image bearing member by said image forming means, on the basis of information of the correction amount corresponding to the detected ambient condition. ### Claim 9 (depends on 5) An apparatus according to claim 5, wherein said storing means stores information of a corresponding relation between the ambient condition and the correction amount as a table storing a value of the correction amount for each color of the developer and for each ambient condition, or stores information of the-s corresponding relation between the ambient condition and the correction amount as an operational expression for calculating a value of the correction amount in accordance with the ambient condition determined from each for each of the developer. ### Claim 10 (depends on 6) An apparatus according to claim 6, wherein said storing means stores information of a corresponding relation between the ambient condition and the correction amount as a table storing a value of the correction amount for each color of the developer and for each ambient condition, or stores information of the-s corresponding relation between the ambient condition and the correction amount as an operational expression for calculating a value of the correction amount in accordance with the ambient condition determined from each for each of the developer. ### Claim 11 (depends on 7) An apparatus according to claim 7, wherein said storing means stores information of a corresponding relation between the ambient condition and the correction amount as a table storing a value of the correction amount for each color of the developer and for each ambient condition, or stores information of the-s corresponding relation between the ambient condition and the correction amount as an operational expression for calculating a value of the correction amount in accordance with the ambient condition determined from each for each of the developer. ### Claim 12 (depends on 8) An apparatus according to claim 8, wherein said storing means stores information of a corresponding relation between the ambient condition and the correction amount as a table storing a value of the correction amount for each color of the developer and for each ambient condition, or stores information of the-s corresponding relation between the ambient condition and the correction amount as an operational expression for calculating a value of the correction amount in accordance with the ambient condition determined from each for each of the developer. ### Claim 13 (depends on 5) An apparatus according to claim 5, wherein the correction amount increases with increase of the temperature or the humidity.