# US 2011/0058871 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 2011/0058871 A1 - Document ID: US20110058871A1 - Status: Published application - Kind: A1 - Application number: 12/876,519 - Filed: 2010-09-07 - Published: 2011-03-10 - Earliest claimed: 2009-09-10 - Assignees: Canon Kabushiki Kaisha - Inventors: Eiichi Motoyama - Web page: https://patentgrep.com/patent/US20110058871A1 ## CPC - B65H 33/06: by displacing articles to define batches - B65H 43/00: Use of control, checking, or safety devices, e.g. automatic devices comprising an element for sensing a variable - G03G 15/232: {using a single reusable electrographic recording member} - G03G 15/6514: {Manual supply devices} - G03G 15/6547: {Shifting sets of sheets in the discharge tray} - 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)} - B65H 2301/4213: of a limited number of articles, e.g. buffering, forming bundles - B65H 2301/4219: forming a pile in which articles are offset from each other, e.g. forming stepped pile - B65H 2511/11: Length - B65H 2511/30: Numbers, e.g. of windings or rotations - B65H 2515/10: Mass, e.g. mass flow rate; Weight; Inertia - G03G 2215/00434: Refeeding tray or cassette - G03G 2215/00485: Thin - G03G 2215/00586: duplex mode - G03G 2215/00738: of sheet thickness or rigidity - G03G 2215/0089: Shifting jobs - B65H: HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An image forming apparatus includes an image forming unit configured to form an image onto each sheet, an ejection unit on which the sheet is ejected, a sorting unit configured to sort the sheets ejected on the ejection unit into subsets, and a control unit configured to, when executing a mode for forming images on first sides of the sheets, ejecting the sheets with the images on the first sides, and forming images on second sides of the ejected sheets manually placed on a feeding unit for second-side image formation, control the sorting unit to sort the ejected sheets after first-side image formation into subsets so that the number of sheets in each subset does not exceed a maximum number of sheets stackable on the feeding unit. ## Claims ### Claim 1 An image forming apparatus comprising: an image forming unit configured to form an image onto each sheet; an ejection unit on which the sheet with the image formed by the image forming unit is ejected; a sorting unit configured to sort the sheets ejected on the ejection unit into subsets; and a control unit configured to, when executing a mode for forming images on first sides of the sheets, ejecting the sheets with the images on the first sides, and forming images on second sides of the ejected sheets manually placed on a feeding unit for second-side image formation, control the sorting unit to sort the ejected sheets after first-side image formation into subsets so that the number of sheets in each subset does not exceed a maximum number of sheets stackable on the feeding unit. ### Claim 2 (depends on 1) The apparatus according to claim 1, further comprising: a setting unit configured to set the number of sheets in each subset so that the number of sheets in the subset does not exceed the maximum number of stackable sheets. ### Claim 3 (depends on 1) The apparatus according to claim 1, further comprising: a specifying unit configured to specify a material of the sheet, wherein the maximum number of stackable sheets varies depending on the specified material. ### Claim 4 (depends on 1) The apparatus according to claim 1, further comprising: a selecting unit configured to select the feeding unit for second-side image formation independently of a feeding unit for first-side image formation. ### Claim 5 An apparatus comprising: an image forming unit configured to form an image onto the sheet fed from a cassette sheet feeding unit or a manual sheet feeding unit; an ejection unit on which the sheet with the image formed by the image forming unit is ejected; a sorting unit configured to sort the sheets ejected on the ejection unit into subsets; and a control unit configured to perform control to allow manual duplex printing so that a first side of each sheet fed from the cassette sheet feeding unit is subjected to image formation and a second side of the sheet ejected on the ejection unit, manually placed on the manual sheet feeding unit, and then fed therefrom is subjected to image formation, wherein in the manual duplex printing, the control unit controls the sorting unit to sort the ejected sheets after first-side image formation into subsets so that the number of sheets in each subset does not exceed a maximum number of sheets stackable on a manual feeding tray. ### Claim 6 (depends on 5) The apparatus according to claim 5, further comprising: a setting unit configured to set the number of sheets in each subset so that the number of sheets in the subset does not exceed the maximum number of stackable sheets. ### Claim 7 (depends on 5) The apparatus according to claim 5, further comprising: a specifying unit configured to specify a material of the sheet, wherein the maximum number of stackable sheets varies depending on the specified material. ### Claim 8 An image forming apparatus comprising: a feeding unit configured to feed each sheet; an image forming unit configured to form an image onto the fed sheet; an ejection unit on which the sheet with the image formed by the image forming unit is ejected; a sorting unit configured to sort the sheets ejected on the ejection unit into subsets; and a control unit configured to, when executing a mode for preparing insert sheets to be used in an inserter by forming images on the fed sheets and ejecting the sheets on the ejection unit, control the sorting unit so that the number of sheets in each subset does not exceed a maximum number of sheets stackable on a tray of the inserter on which the insert sheets to be fed are placed. ### Claim 9 (depends on 8) The apparatus according to claim 8, wherein the control unit controls the sorting unit so that the number of sheets in each subset is at or below the maximum number of sheets stackable on the tray and is an integer multiple of the number of insert sheets in one set. ### Claim 10 (depends on 8) The apparatus according to claim 8, wherein the image forming apparatus includes the inserter. ### Claim 11 A method comprising: forming an image onto each sheet; sorting sheets ejected on an ejection tray into subsets; and when executing a mode for forming images on first sides of the sheets, ejecting the sheets with the images on the first sides, and forming images on second sides of the ejected sheets manually placed on a feeding unit for second-side image formation, controlling the sorting to sort the ejected sheets after first-side image formation into subsets so that the number of sheets in each subset does not exceed a maximum number of sheets stackable on the feeding unit. ### Claim 12 (depends on 11) The method according to claim 11, further comprising: setting the number of sheets in each subset so that the number of sheets in the subset does not exceed the maximum number of stackable sheets. ### Claim 13 (depends on 11) The method according to claim 11, further comprising: specifying a material of the sheet, wherein the maximum number of stackable sheets varies depending on the specified material. ### Claim 14 (depends on 11) The method according to claim 11, further comprising: selecting the feeding unit for second-side image formation independently of a feeding unit for first-side image formation.