# US 7,610,004 B2 · Apparatus for detecting amount of toner deposit and controlling density of image, method of forming misalignment correction pattern, and apparatus for detecting and correcting misalignment of image > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,610,004 B2 - Document ID: US7610004B2 - Status: Granted - Kind: B2 - Application number: 11/677,484 - Filed: 2007-02-21 - Published: 2007-06-14 - Granted: 2009-10-27 - Earliest claimed: 2003-06-25 - Assignees: Ricoh Company, Ltd. - Inventors: Shinji Kato; Yuuji Sawai; Hiromi Ogiyama; Shin Kayahara; Atsushi Takehara; Ken Yoshida; Yoshihiro Fujiwara - Web page: https://patentgrep.com/patent/US7610004B2 ## CPC - G03G 15/5058: {using a test patch} - G03G 15/0131: {for transferring a pattern to a second base} - G03G 2215/00029: Image density detection - G03G 2215/00059: on intermediate image carrying member, e.g. transfer belt - G03G 2215/00063: Colour - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An image forming apparatus includes a reference-pattern detecting transfer-body, a reference-pattern detecting unit, and a condition changing unit. The reference-pattern detecting transfer-body directly transfers a reference pattern image formed on an intermediate transfer body without a recording material. The reference-pattern detecting unit detects an optical reference pattern with respect to the image transferred onto the reference-pattern detecting transfer-body. The condition changing unit changes the image forming conditions based on a result of detection. ## Claims ### Claim 1 An apparatus for correcting a misalignment, comprising: a pattern forming unit that forms a misalignment correction pattern on an intermediate transfer body, the misalignment correction pattern including a plurality of patches in which a reference color pattern at a reference position and a correction target color pattern formed in a correction target color are superposed; a sensor that optically reads the misalignment correction pattern formed, the sensor including a first sensing unit configured to read a regular reflection component and a second sensing unit configured to read a diffuse reflection component, wherein the first sensing unit and the second sensing unit are arranged with a light source there-in-between; a detecting unit that detects and identifies the diffuse and regular reflection components optically read by the sensor; a calculating unit that calculates an amount of misalignment of the correction target color with respect to the reference position based on a result of detection by the detecting unit; and a correcting unit that corrects the misalignment of the correction target color based on the amount of misalignment calculated. ### Claim 2 (depends on 1) The apparatus according to claim 1, wherein the pattern forming unit includes a first forming unit that forms the correction target color pattern including at least one line formed in the correction target color or a plurality of lines formed in the correction target color at a predetermined pitch on the intermediate transfer body; and a second forming unit that forms the reference color pattern including at least one line formed with black toner or a plurality of lines formed with black toner at same pitch as the predetermined pitch, superposing on the correction target color pattern in such a manner that a patch of the reference color pattern and the correction target color pattern superposed is continuously arranged with respect to a reading direction of a sensor by shifting the reference color pattern by a predetermined distance from a position where the reference color pattern and the correction target color pattern are completely in an overlapped state to a position where the reference color pattern and the correction target color pattern are completely out of the overlapped state. ### Claim 3 (depends on 1) The apparatus according to claim 1, wherein the sensor is a reflection-type photosensor. ### Claim 4 (depends on 3) The apparatus according to claim 3, wherein a gloss level of the intermediate transfer body is set based on an output of regular reflection component when the reflection-type photosensor optically reads the misalignment correction pattern. ### Claim 5 (depends on 4) The apparatus according to claim 4, wherein the gloss level of the intermediate transfer body is set based on signal-to-noise ratio of the output of regular reflection component from the intermediate transfer body and the misalignment correction pattern. ### Claim 6 (depends on 3) The apparatus according to claim 3, wherein the calculating unit calculates the amount of misalignment from a position of intersection of two segments obtained based on an output of the reflection-type photosensor. ### Claim 7 (depends on 3) The apparatus according to claim 3, wherein the reflection-type photosensor includes a light emitting element that emits light; and a light detecting element that is arranged at a position for detecting the regular reflection component of the light. ### Claim 8 (depends on 3) The apparatus according to claim 3, wherein a lightness of the intermediate transfer body is set based on an output of diffuse reflection component when the reflection-type photosensor optically reads the misalignment correction pattern. ### Claim 9 (depends on 8) The apparatus according to claim 8, wherein the reflection-type photosensor includes a light emitting element that emits light; and a light detecting element that is arranged at a position for detecting the regular reflection component of the light. ### Claim 10 (depends on 8) The apparatus according to claim 8, wherein the lightness of the intermediate transfer body is equal to or less than 25. ### Claim 11 (depends on 8) The apparatus according to claim 8, wherein a variation of the lightness of the intermediate transfer body in a circumferential direction is equal to or less than 10. ### Claim 12 (depends on 3) The apparatus according to claim 3, wherein a patch length that is a length in a reading direction of the reflection-type photosensor, a patch interval, and a spot diameter of the reflection-type photosensor on the intermediate transfer body satisfies patch length+patch interval>spot diameter×2. ### Claim 13 (depends on 1) The apparatus according to claim 1, wherein a gloss level of the intermediate transfer body is equal to or more than 60 in the gloss level according to JISZ8741 gloss level standard. ### Claim 14 (depends on 1) The apparatus according to claim 1, wherein a variation of a gloss level of the intermediate transfer body in a circumferential direction is equal to or less than 10. ### Claim 15 An image forming apparatus comprising: an intermediate transfer body on which images formed on a plurality of image carriers are superposed and transferred; a pattern forming unit that forms a misalignment correction pattern including a plurality of patches in which a reference color pattern at a reference position and a correction target color pattern formed in a correction target color are superposed on the intermediate transfer body; a sensor that optically reads the misalignment correction pattern formed, the sensor including a first sensing unit configured to read a regular reflection component and a second sensing unit configured to read a diffuse reflection component, wherein the first sensing unit and the second sensing unit are arranged with a light source there-in-between; a detecting unit that detects and identifies the diffuse and regular reflection components optically read by the sensor; a calculating unit that calculates an amount of misalignment of the correction target color with respect to the reference position based on a result of detection by the detecting unit; a correcting unit that corrects the misalignment of the correction target color based on the amount of misalignment calculated; and an image forming unit that forms a color image at a corrected position. ### Claim 16 A method of correcting misalignment, comprising: forming a plurality of correction target color patterns in a correction target color on an intermediate transfer body, on which images formed on a plurality of image carriers are superposed and transferred, along the rotation direction of the intermediate transfer body; forming a plurality of reference color patterns at a reference position on the correction target color patterns and on the intermediate transfer body; detecting an amount of light reflected from the reference color patterns and the correction target color patterns using a sensor, the sensor detecting and identifying diffuse and regular reflection components using a first sensing unit to read a regular reflection component and a second sensing unit to read a diffuse reflection component, the first sensing unit and the second sensing unit being arranged with a light source there-in-between; calculating an amount of misalignment of the correction target color with respect to the reference position based on a result of the detecting; and correcting the misalignment of the correction target color based on the amount of misalignment calculated. ### Claim 17 (depends on 16) The method according to claim 16, wherein the forming a plurality of correction target color patterns includes forming the correction target color patterns including at least one line formed in the correction target color or a plurality of lines formed in the correction target color at a predetermined pitch, and the forming a plurality of reference color patterns includes forming the reference color patterns including at least one line formed with black toner or a plurality of lines formed with black toner at same pitch as the predetermined pitch, superposing on the correction target color pattern in such a manner that a patch of the reference color pattern and the correction target color pattern superposed is continuously arranged with respect to a reading direction of a sensor by shifting the reference color pattern by a predetermined distance from a position where the reference color pattern and the correction target color pattern are completely in an overlapped state to a position where the reference color pattern and the correction target color pattern are completely out of the overlapped state. ### Claim 18 A computer readable recording medium that stores a computer program for correcting a misalignment, the computer program making a computer to execute: forming a plurality of correction target color patterns in a correction target color on an intermediate transfer body, on which images formed on a plurality of image carriers are superposed and transferred, along the rotation direction of the intermediate transfer body; forming a plurality of reference color patterns at a reference position on the correction target color patterns and on the intermediate transfer body; detecting an amount of light reflected from the reference color patterns and the correction target color patterns using a sensor, the sensor detecting and identifying diffuse and regular reflection components using a first sensing unit to read a regular reflection component and a second sensing unit to read a diffuse reflection component, the first sensing unit and the second sensing unit being arranged with a light source there-in-between; calculating an amount of misalignment of the correction target color with respect to the reference position based on a result of the detecting; and correcting the misalignment of the correction target color based on the amount of misalignment calculated. ### Claim 19 (depends on 18) The computer readable medium according to claim 18, wherein the forming a plurality of correction target color patterns includes forming the correction target color patterns including a plurality of lines formed in the correction target color at a predetermined pitch, and the forming a plurality of reference color patterns includes forming the reference color patterns including a plurality of lines formed with black toner at same pitch as the predetermined pitch, superposing on the correction target color pattern in such a manner that a patch of the reference color pattern and the correction target color pattern superposed is continuously arranged with respect to a reading direction of a sensor by shifting the reference color pattern by a predetermined distance from a position where the reference color pattern and the correction target color pattern are completely in an overlapped state to a position where the reference color pattern and the correction target color pattern are completely out of the overlapped state.