# US 2019/0377280 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 2019/0377280 A1 - Document ID: US20190377280A1 - Status: Published application - Kind: A1 - Application number: 16/548,186 - Filed: 2019-08-22 - Published: 2019-12-12 - Earliest claimed: 2015-11-30 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Tomohiro Hashimoto; Tsutomu Ishida; Masafumi Monde - Web page: https://patentgrep.com/patent/US20190377280A1 ## CPC - G03G 15/043: with means for controlling illumination or exposure (G03G15/041 takes precedence) - G03G 15/5029: {by measuring the copy material characteristics, e.g. weight, thickness} - G03G 15/6591: {characterised by the recording material, e.g. plastic material, OHP, ceramics, tiles, textiles (details transferring the toner pattern onto particular materials G03G15/1625)} - G03G 2215/00945: Copy material feeding speed varied over the feed path - G03G 2215/2045: Variable fixing speed - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An image forming apparatus includes a conveyance unit, an irradiation unit, an image capturing unit configured to capture a plurality of times the light radiated by the irradiation unit and reflected on the recording material as surface images, an image formation unit, and a control unit, wherein the conveyance unit accelerates or decelerates a conveyance speed of the recording material in at least a part of an image capturing period during which the image capturing unit captures the surface images the plurality of times, and wherein the control unit obtains a feature quantity from a plurality of surface images captured by the image capturing unit and controls the image forming condition based on the obtained feature quantity and a threshold value set according to the conveyance speed of the recording material in the image capturing period. ## Claims ### Claim 1 An image forming apparatus comprising: a conveyance unit configured to convey a recording material on a conveyance path in the image forming apparatus; an irradiation unit configured to radiate light on segments of the recording material being conveyed by the conveyance unit, the light radiated on a segment of the recording material as the segment is being conveyed through an irradiation section of the conveyance path; an image capturing unit configured to capture surface images of a plurality of segments of the recording material by capturing, for a plurality of times during an image capturing period, as a surface image, the light radiated by the irradiation unit and reflected on the recording material, wherein the plurality of times corresponds to the plurality of segments; an image formation unit configured to form an image on a recording material; and a control unit configured to control an image forming condition of the image formation unit, wherein the conveyance unit accelerates or decelerates a conveyance speed of the recording material in at least a part of the image capturing period during which the image capturing unit captures the surface images the plurality of times, wherein the image forming apparatus obtains feature quantity data on the basis of data obtained from the captured surface images, wherein the feature quantity data reflects a feature of the recording material, and wherein the control unit controls the image forming condition based on the obtained feature quantity data and an average conveyance speed of the recording material in the image capturing period. ### Claim 2 (depends on 1) The image forming apparatus according to claim 1, wherein the control unit corrects the obtained feature quantity data based on the number of times the image capturing unit captures the surface images, and controls the image forming condition based on the corrected feature quantity data and the corrected threshold value. ### Claim 3 (depends on 1) The image forming apparatus according to claim 1, wherein, in the plurality of surface images captured by the image capturing unit, a plurality of pixels exists in each of a first column and a second column parallel to a conveyance direction of the recording material, and wherein the control unit obtains the feature quantity data by integrating an amount of change of output values of a plurality of pixels arranged in the first column and an amount of change of output values of a plurality of pixels arranged in the second column. ### Claim 4 (depends on 3) The image forming apparatus according to claim 3, wherein, in the plurality of surface images captured by the image capturing unit, a plurality of pixels exists in a predetermined column parallel to the conveyance direction of the recording material, and wherein, with respect to all of the pixels existing in the predetermined column, the control unit obtains an amount of change of output values of the plurality of pixels by obtaining and integrating an absolute value of a difference of output values of two pixels adjacent to one another in the conveyance direction of the recording material. ### Claim 5 (depends on 1) The image forming apparatus according to claim 1, wherein the image formation unit includes a transfer unit configured to transfer an image on a recording material, and wherein, in a case where the conveyance unit stops the recording material at a predetermined position on an upstream side of the transfer unit in a conveyance direction of the recording material to allow the control unit to control the image forming condition with respect to the recording material after the surface images of the recording material are captured by the image capturing unit, the conveyance unit decelerates a conveyance speed of the recording material in at least a part of the image capturing period to stop the recording material at the predetermined position. ### Claim 6 (depends on 5) The image forming apparatus according to claim 5, wherein, in a case where an image is formed on a first recording material by the image formation unit, the conveyance unit stops the recording material at the predetermined position. ### Claim 7 (depends on 5) The image forming apparatus according to claim 5 further comprising a storage unit configured to store the average conveyance speed of the recording material in the image capturing period, wherein the control unit controls the image forming condition based on the obtained feature quantity data and the threshold value set according to the average conveyance speed of the recording material stored in the storage unit. ### Claim 8 (depends on 1) The image forming apparatus according to claim 1 further comprising a detection unit configured to detect a recording material on an upstream side of the image formation unit in the conveyance direction of the recording material, wherein the image formation unit includes a transfer unit configured to transfer an image on a recording material, and wherein, in a case where the conveyance unit accelerates or decelerates a conveyance speed of the recording material without stopping the recording material to allow the transfer unit to transfer the image on the recording material based on a timing at which the recording material is detected by the detection unit, the conveyance unit accelerates or decelerates the conveyance speed of the recording material in at least a part of the image capturing period. ### Claim 9 (depends on 8) The image forming apparatus according to claim 8, wherein, in a case where an image is formed on a second recording material by the image formation unit, the conveyance unit accelerates or decelerates conveyance speeds of the second recording material without stopping the second recording material. ### Claim 10 (depends on 8) The image forming apparatus according to claim 8, wherein the control unit obtains the average conveyance speed of the recording material in the image capturing period based on the timing at which the detection unit detects the recording material, and controls the image forming condition based on the obtained feature quantity data and the threshold value set according to the obtained average conveyance speed of the recording material. ### Claim 11 (depends on 1) The image forming apparatus according to claim 1, wherein, in the image capturing period, the irradiation unit does not change an amount of light radiated on the recording material, and the image capturing unit does not change a light receiving period for receiving and capturing light reflected on the recording material as a surface image once. ### Claim 12 (depends on 1) The image forming apparatus according to claim 1, wherein the image capturing unit is a line sensor including a plurality of light receiving elements arranged in a direction parallel to a conveyance surface of the recording material and orthogonal to the conveyance direction of the recording material. ### Claim 13 (depends on 1) The image forming apparatus according to claim 1, wherein the image forming condition is a conveyance speed of a recording material, a voltage value applied to a transfer unit included in the image formation unit, or a temperature at which a fixing unit included in the image formation unit fixes an image on a recording material. ### Claim 14 An image forming apparatus comprising: a conveyance unit configured to convey a recording material on a conveyance path in the image forming apparatus; an irradiation unit configured to radiate light on segments of the recording material being conveyed by the conveyance unit, the light radiated on a segment of the recording material as the segment is being conveyed through an irradiation section of the conveyance path; an image capturing unit configured to capture surface images of a plurality of segments of the recording material by capturing, for a plurality of times during an image capturing period, as a surface image, the light radiated by the irradiation unit and reflected on the recording material, wherein the plurality of times corresponds to the plurality of segments; an image formation unit configured to form an image on a recording material; and a control unit configured to control an image forming condition of the image formation unit, wherein the conveyance unit accelerates or decelerates a conveyance speed of the recording material in at least a part of the image capturing period during which the image capturing unit captures the surface images the plurality of times, wherein the image forming apparatus obtains feature quantity data on the basis of data obtained from the captured surface images, wherein the feature quantity data reflects a feature of the recording material, and wherein the control unit corrects the obtained feature quantity data based on an average conveyance speed of the recording material during the image capturing period, and controls the image forming condition based on the corrected feature quantity data. ### Claim 15 (depends on 14) The image forming apparatus according to claim 14, wherein the control unit further corrects the corrected feature quantity data based on the number of times the image capturing unit captures the surface images and controls the image forming condition based on the further corrected feature quantity data and the preset threshold value. ### Claim 16 (depends on 14) The image forming apparatus according to claim 14, wherein, in the plurality of surface images captured by the image capturing unit, a plurality of pixels exists in each of a first column and a second column parallel to a conveyance direction of a recording material, and wherein the control unit obtains the feature quantity data by integrating an amount of change of output values of the plurality of pixels arranged in the first column and an amount of change of output values of the plurality of pixels arranged in the second column. ### Claim 17 (depends on 16) The image forming apparatus according to claim 16, wherein, in the plurality of surface images captured by the image capturing unit, a plurality of pixels exists in a predetermined column parallel to the conveyance direction of the recording material, and wherein, with respect to all of the pixels existing in the predetermined column, the control unit obtains an amount of change of output values of the plurality of pixels by obtaining and integrating an absolute value of a difference of output values of two pixels adjacent to one another in the conveyance direction of the recording material. ### Claim 18 (depends on 14) The image forming apparatus according to claim 14, wherein the image formation unit includes a transfer unit configured to transfer an image on the recording material, and wherein, in a case where the conveyance unit stops the recording material at a predetermined position on an upstream side of the transfer unit in a conveyance direction of the recording material, to allow the control unit to control the image forming condition with respect to the recording material after the surface images of the recording material are captured by the image capturing unit, the conveyance unit decelerates a conveyance speed of the recording material in at least a part of the image capturing period to stop the recording material at the predetermined position. ### Claim 19 (depends on 18) The image forming apparatus according to claim 18, wherein, in a case where an image is formed on a first recording material by the image formation unit, the conveyance unit stops the recording material at the predetermined position. ### Claim 20 (depends on 18) The image forming apparatus according to claim 18 further comprising a storage unit configured to store the average conveyance speed of the recording material in the image capturing period, wherein the control unit further corrects the corrected feature quantity data based on an average conveyance speed of the recording material stored in the storage unit and controls the image forming condition based on the further corrected feature quantity data and the threshold value. ### Claim 21 (depends on 14) The image forming apparatus according to claim 14 further comprising a detection unit configured to detect a recording material on an upstream side of the image formation unit in the conveyance direction of the recording material, wherein the image formation unit includes a transfer unit configured to transfer an image on the recording material, and wherein, in a case where the conveyance unit accelerates or decelerates a conveyance speed of the recording material without stopping the recording material to allow the transfer unit to transfer the image on the recording material based on a timing at which the recording material is detected by the detection unit, the conveyance unit accelerates or decelerates the conveyance speed of the recording material in at least a part of the image capturing period. ### Claim 22 (depends on 21) The image forming apparatus according to claim 21, wherein, in a case where an image is formed on a second recording material by the image formation unit, the conveyance unit accelerates or decelerates conveyance speeds of the second recording material without stopping the second recording material. ### Claim 23 (depends on 21) The image forming apparatus according to claim 21, wherein the control unit obtains the average conveyance speed of a recording material in the image capturing period based on the timing at which the recording material is detected by the detection unit, further corrects the corrected feature quantity data based on the average conveyance speed of the recording material, and controls the image forming condition based on the corrected feature quantity data and the preset threshold value. ### Claim 24 (depends on 14) The image forming apparatus according to claim 14, wherein, in the image capturing period, the irradiation unit does not change an amount of light radiated to the recording material, and the image capturing unit does not change a light receiving period for receiving and capturing light reflected on the recording material as a surface image once. ### Claim 25 (depends on 14) The image forming apparatus according to claim 14, wherein the image capturing unit is a line sensor including a plurality of light receiving elements arranged in a direction parallel to a conveyance surface of a recording material and orthogonal to a conveyance direction of the recording material. ### Claim 26 (depends on 14) The image forming apparatus according to claim 14, wherein the image forming condition is a conveyance speed of a recording material, a voltage value applied to a transfer unit included in the image formation unit, or a temperature at which a fixing unit included in the image formation unit fixes an image on a recording material.