# US 2016/0355355 A1 · Sheet feeding device and 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 2016/0355355 A1 - Document ID: US20160355355A1 - Status: Published application - Kind: A1 - Application number: 15/165,367 - Filed: 2016-05-26 - Published: 2016-12-08 - Earliest claimed: 2015-06-03 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Marehiko Hirajima - Web page: https://patentgrep.com/patent/US20160355355A1 ## CPC - B65H 1/08: with means for advancing the articles to present the articles to the separating device {(B65H1/02 takes precedence)} - B65H 1/04: adapted to support articles substantially horizontally, e.g. for separation from top of pile - B65H 1/14: comprising positively-acting mechanical devices {(B65H1/025 takes precedence)} - B65H 1/18: controlled by height of pile - B65H 1/266: {Support fully or partially removable from the handling machine, e.g. cassette, drawer (B65H1/027 takes precedence)} - B65H 3/0684: {on moving support, e.g. pivoting, for bringing the roller or like rotary separator into contact with the pile} - B65H 7/02: by feelers or detectors - B65H 7/14: by photoelectric feelers or detectors - B65H 7/20: Controlling associated apparatus - G03G 15/6511: {Feeding devices for picking up or separation of copy sheets} - G03G 15/6529: {Transporting (G03G15/6555 takes precedence)} - B65H 2405/1117: pivotable, e.g. around an axis perpendicular to transport direction, e.g. arranged at rear side of sheet support - B65H 2405/11172: around an axis perpendicular to both transport direction and surface of sheets - B65H 2405/313: with integrated handling means, e.g. separating means - B65H 2407/21: Manual feeding - B65H 2511/20: Location in space - B65H 2511/30: Numbers, e.g. of windings or rotations - B65H 2511/51: Presence - B65H 2513/50: Timing - G03G 2215/00396: Pick-up device - G03G 2215/004: Separation device - G03G 2215/0132: vertical medium transport path at the secondary transfer - B65H: HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract A sheet feeding device includes a raising and lowering portion, a first detecting portion, a feeding portion, a second detecting portion, and a controller. When a change in a state of the feeding roller from a state of being in an uppermost sheet feedable position to a state of being not in the uppermost sheet feedable position is detected by the second detecting portion and then a change in a state of the uppermost sheet from a state of being in a feeding position to a state of being not in the feeding position is detected by the first detecting portion, the controller controls the raising and lowering portion to raise the stacking member on the basis of a correction amount determined based on a time from change timing of the second detecting portion to change timing of the first detecting portion. ## Claims ### Claim 1 A sheet feeding device comprising: a raising and lowering portion for raising and lowering a stacking member for stacking a sheet; a first detecting portion for detecting whether or not an uppermost sheet stacked on said stacking member raised by said raising and lowering portion is in a feeding position; a feeding portion for feeding the uppermost sheet by causing a feeding roller to press contact the uppermost sheet; a second detecting portion for detecting whether or not the feeding roller is in a position where the feeding roller is capable of feeding the uppermost sheet; and a controller for controlling said raising and lowering portion, wherein said raising and lowering portion raises said stacking member and detection that the uppermost sheet is in the feeding position is made by said first detecting portion, and thereafter said feeding portion causes the feeding roller to press contact the uppermost sheet, and wherein when a change in a state of the feeding roller from a state in which the feeding roller is in the position where the feeding roller is capable of feeding the uppermost sheet to a state in which the feeding roller is not in the position where the feeding roller is capable of feeding the uppermost sheet is detected by said second detecting portion and then a change in a state of the uppermost sheet from a state in which the uppermost sheet is in the feeding position to a state in which the uppermost sheet is not in the feeding position is detected by said first detecting portion, said controller determines a correction amount on the basis of a time from change timing of said second detecting portion to change timing of said first detecting portion and controls said raising and lowering portion to raise said stacking member on the basis of the correction amount. ### Claim 2 (depends on 1) A sheet feeding device according to claim 1, wherein when a change in a state of the feeding roller from a state in which the feeding roller is in the position where the feeding roller is capable of feeding the uppermost sheet to a state in which the feeding roller is not in the position where the feeding roller is capable of feeding the uppermost sheet is detected by said second detecting portion and when a change in a state of the uppermost sheet from a state in which the uppermost sheet is in the feeding position to a state in which the uppermost sheet is not in the feeding position is not detected by said first detecting portion, said controller determines a correction amount smaller than said correction amount determined on the basis of the time and controls said raising and lowering portion to raise said stacking member. ### Claim 3 (depends on 1) A sheet feeding device according to claim 1, wherein when a change in a state of the feeding roller from a state in which the feeding roller is in the position where the feeding roller is capable of feeding the uppermost sheet to a state in which the feeding roller is not in the position where the feeding roller is capable of feeding the uppermost sheet is not detected by said second detecting portion and when a change in a state of the uppermost sheet from a state in which the uppermost sheet is in the feeding position to a state in which the uppermost sheet is not in the feeding position is not detected by said first detecting portion, said controller does not control said raising and lowering portion and said feeding portion feeds the uppermost sheet by the feeding roller. ### Claim 4 (depends on 1) A sheet feeding device according to claim 1, wherein when the time is long, said controller increase the correction amount compared with when the time is short. ### Claim 5 (depends on 1) A sheet feeding device according to claim 1, wherein said feeding portion effects contact and spacing of the feeding roller relative to the uppermost sheet every feeding of one sheet. ### Claim 6 (depends on 1) A sheet feeding device according to claim 1, wherein the feeding roller press contacts the uppermost sheet to correct a curl state of the sheet stacked on said stacking member. ### Claim 7 (depends on 1) A sheet feeding device according to claim 1, wherein said controller controls said raising and lowering portion on the basis of the time to raises said stacking member to a position higher than the feeding position. ### Claim 8 (depends on 7) A sheet feeding device according to claim 7, wherein after said stacking member is raised correspondingly to the determined correction amount, said feeding portion feeds the uppermost sheet by the feeding roller. ### Claim 9 (depends on 1) An image forming apparatus according to claim 1, wherein said controller determines a remaining sheet amount of the sheet stacked on said stacking member on the basis of the determined correction amount. ### Claim 10 (depends on 9) A sheet feeding device according to claim 9, wherein the remaining sheet amount is a proportion to a maximum number of sheets capable of being stacked on the stacking member. ### Claim 11 (depends on 9) A sheet feeding device according to claim 9, wherein the remaining sheet amount is a number of sheets stacked on the stacking member. ### Claim 12 (depends on 11) A sheet feeding device according to claim 11, wherein the number of sheets is a number of sheets depending on a species of paper of the sheets. ### Claim 13 An image forming apparatus comprising: a raising and lowering portion for raising and lowering a stacking member for stacking a sheet; a first detecting portion for detecting whether or not an uppermost sheet stacked on said stacking member raised by said raising and lowering portion is in a feeding position; a feeding portion for feeding the uppermost sheet by causing a feeding roller to press contact the uppermost sheet; a second detecting portion for detecting whether or not the feeding roller is in a position where the feeding roller is capable of feeding the uppermost sheet; and a controller for controlling said raising and lowering portion, wherein said raising and lowering portion raises said stacking member and detection that the uppermost sheet is in the feeding position is made by said first detecting portion, and thereafter said feeding portion causes the feeding roller to press contact the uppermost sheet, and wherein when a change in a state of the feeding roller from a state in which the feeding roller is in the position where the feeding roller is capable of feeding the uppermost sheet to a state in which the feeding roller is not in the position where the feeding roller is capable of feeding the uppermost sheet is detected by said second detecting portion and then a change in a state of the uppermost sheet from a state in which the uppermost sheet is in the feeding position to a state in which the uppermost sheet is not in the feeding position is detected by said first detecting portion, said controller determines a correction amount on the basis of a time from change timing of said second detecting portion to change timing of said first detecting portion and controls said raising and lowering portion to raise said stacking member on the basis of the correction amount. ### Claim 14 (depends on 13) An image forming apparatus according to claim 13, wherein said controller determines a remaining sheet amount of the sheet stacked on said stacking member on the basis of the determined correction amount. ### Claim 15 (depends on 14) An image forming apparatus according to claim 14, further comprising: a notifying portion for notifying information, wherein said notifying portion notifies the remaining sheet amount. ### Claim 16 (depends on 15) An image forming apparatus according to claim 15, further comprising: a third detecting portion for detecting a species of paper of the sheet, wherein said notifying portion notifies a number of sheets depending on the species of paper of the sheet detected by said third detecting portion.