# US 5,702,191 A · Sheet feeding force control in a multiple input path sheet feeding apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,702,191 A - Document ID: US5702191A - Status: Granted - Kind: A - Application number: 08/353,392 - Filed: 1994-12-02 - Granted: 1997-12-30 - Earliest claimed: 1990-01-30 - Assignees: Canon Kabushiki Kaisha - Inventors: Masaaki Kakizaki; Hirofumi Hirano; Toshihiko Bekki - Web page: https://patentgrep.com/patent/US5702191A ## CPC - B65H 7/02: by feelers or detectors - B41J 13/076: Construction of rollers; Bearings therefor - B41J 13/10: Sheet holders, retainers {, movable guides}, or stationary guides - B65H 3/68: immovable in operation - B65H 5/00: Feeding articles separated from piles; Feeding articles to machines ({B65H9/00 takes precedence; } identical mechanisms or parts for delivering or advancing articles from machines B65H29/00; recirculating articles B65H85/00 {, G03B27/6257}) - B65H 2511/514: Particular portion of element - B65H 2515/30: Forces; Stresses - B65H 2701/1311: leading edge - B65H: HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS ## Abstract A sheet feeding apparatus includes a conveyor for applying a conveying force to a sheet, a first guide for guiding the sheet to which the conveying force is applied from the conveyor, a second guide for guiding the sheet guided by the first guide along a curved path, a driver for driving the conveyor, and a controller for controlling the driver to increase the conveying force of the conveyor when the sheet being conveyed by the conveyor is guided with being abutted against the second guide. ## Claims ### Claim 1 A sheet feeding apparatus comprising: conveying means having a convey roller for applying a conveying force to a sheet; first guide means for guiding the sheet to which the conveying force is applied by said conveying means; second guide means against which a tip end of the sheet guided by said first guide means abuts, for guiding the sheet in a direction changing an advancing direction of the sheet, and forming a first path together with said first guide means, wherein in the first path the sheet is conveyed by said conveying means; third guide means, forming a second path joining to the first path at a position downstream of said first guide means and upstream of said second guide means, for guiding a sheet to said second guide means; and control means for controlling said conveying means so that the conveying force of said conveying means is increased from an initial value when a tip end of the sheet that is being guided by said first guide means reaches a first predetermined position upstream of said second guide means without interrupting sheet conveyance, and is returned to the initial value when the tip end of the sheet that is being guided by said second guide means reaches a second predetermined position downstream of an abut position where the sheet abuts said second guide means, thereby feeding the sheet to a third predetermined position under the initial conveying force. ### Claim 2 (depends on 1) A sheet feeding apparatus according to claim 1, wherein said control means increases the conveying force of said conveying means by decreasing the convey speed of said conveying means. ### Claim 3 (depends on 1) A sheet feeding apparatus according to claim 1, wherein said conveying means comprises a stepping motor. ### Claim 4 (depends on 1) A sheet feeding apparatus according to claim 1, wherein said conveying means includes a rotary conveying member a peripheral surface of which contacts the sheet. ### Claim 5 (depends on 1) A sheet feeding apparatus according to claim 1, wherein said first and second guide means guide the sheet along said conveying means. ### Claim 6 (depends on 4) A sheet feeding apparatus according to claim 4, wherein said second guide means has an urging portion which urges the sheet against said rotary conveying member. ### Claim 7 (depends on 1) A sheet feeding apparatus according to claim 1, wherein said drive means includes a driving force transmitting mechanism capable of changing a speed reduction ratio. ### Claim 8 (depends on 1) A sheet feeding apparatus according to claim 1, wherein said second guide means includes a driven rotary member which urges the sheet against said conveying means and which is driven by the sheet conveyed by said conveying means. ### Claim 9 (depends on 1) A sheet feeding apparatus according to claim 1, further including a recording means for recording an image on the sheet conveyed by said conveying means. ### Claim 10 (depends on 9) A sheet feeding apparatus according to claim 9, wherein said recording means includes an ink jet head for discharging ink. ### Claim 11 (depends on 10) A sheet feeding apparatus according to claim 10, wherein said ink jet head records the image with the ink discharged by thermal energy. ### Claim 12 (depends on 1) A sheet feeding apparatus according to claim 1, further comprising image forming means disposed downstream of said second guide means for forming an image to the sheet conveyed by said conveying means. ### Claim 13 A sheet feeding apparatus comprising: conveying means having a convey roller for applying a conveying force to a sheet; first guide means for guiding the sheet to which the conveying force is applied by said conveying means; second guide means against which a tip end of the sheet guided by said first guide means abuts, for guiding the sheet in a direction changing an advancing direction of the sheet and forming a first path together with said first guide means, wherein in the first path the sheet is conveyed by said conveying means; third guide means, forming a second path joining to the first path at a position downstream of said first guide means and upstream of said second guide means, for guiding a sheet to a said second guide means; and control means for controlling said conveying means so that the conveying force of said conveying means is changed from a first convey force to a second convey force larger than the first convey force when a tip end of the sheet that is being guided by said first guide means reaches a first predetermined position upstream of said second guide means without interrupting sheet conveyance, and is changed to a third convey force smaller than the second convey force when a tip end of the sheet that is being guided by said second guide means reaches a second predetermined position downstream of an abut position where the sheet abuts said second guide means, to thereby feed the sheet to a third predetermined position under the third convey force. ### Claim 14 (depends on 13) A sheet feeding apparatus according to claim 13, wherein said control means increases the conveying force of said conveying means by decreasing the convey speed of said conveying means. ### Claim 15 (depends on 14) A sheet feeding apparatus according to claim 14, wherein said conveying means comprises a stepping motor. ### Claim 16 (depends on 13) A sheet feeding apparatus according to claim 13, wherein said first and second guide means guide the sheet along said conveying means. ### Claim 17 (depends on 13) A sheet feeding apparatus according to claim 13, wherein said conveying means includes a driving force transmitting mechanism capable of changing a speed reduction ratio. ### Claim 18 (depends on 17) A sheet feeding apparatus to claim 17, further including a recording means for recording an image on the sheet conveyed by said conveying means. ### Claim 19 (depends on 18) A sheet feeding apparatus according to claim 18, wherein said recording means includes an ink jet head for discharging ink. ### Claim 20 (depends on 19) A sheet feeding apparatus according to claim 19, wherein said ink jet head records the image with the ink discharged by thermal energy. ### Claim 21 (depends on 13) A sheet feeding apparatus according to claim 13, wherein said drive means comprises a motor. ### Claim 22 (depends on 21) A sheet feeding apparatus according to claim 21, wherein said control means changes the conveying force of said conveying means by changing an output of said motor. ### Claim 23 (depends on 22) A sheet feeding apparatus according to claim 22, wherein said control means sets the conveying force of said conveying means in the second convey force by increasing a voltage supplied to said motor. ### Claim 24 (depends on 13) A sheet feeding apparatus according to claim 13, further comprising image forming means disposed downstream of said second guide means for forming an image to the sheet conveyed by said conveying means. ### Claim 25 An image forming apparatus comprising: conveying means having a convey roller for applying a conveying force to a sheet; first guide means for guiding the sheet to which the conveying force is applied by said conveying means; second guide means, against which a tip end of the sheet guided by said first guide means abuts, for guiding the sheet in a direction changing an advancing direction of the sheet, and forming a first path together with said first guide means, wherein in the first path the sheet is conveyed by said conveying means; third guide means forming a second path joining to the first path at a position downstream of said first guide means and upstream of said second guide means, for guiding the sheet to said second guide means; image forming means disposed downstream of said second guide means for forming an image on the sheet conveyed by said conveying means; and control means for controlling said conveying means so that the conveying force thereof is increased from an initial value when a tip end of the sheet that is being guided by said first guide means reaches a first predetermined position upstream of said second guide means without interrupting sheet conveyance, and is returned to the initial value when the tip end of the sheet that is being guided by said second guide means reaches a second predetermined position downstream of an abut position where the sheet abuts said second guide means, to thereby feed the sheet to a third predetermined position under the initial conveying force. ### Claim 26 (depends on 25) A sheet feeding apparatus according to claim 25, wherein said recording means includes an ink jet head for discharging ink. ### Claim 27 (depends on 26) A sheet feeding apparatus according to claim 26, wherein said ink jet head records the image with the ink discharged by thermal energy. ### Claim 28 (depends on 1) A sheet feeding apparatus according to claim 1, wherein said conveying means comprises a motor. ### Claim 29 (depends on 13) A sheet feeding apparatus according to claim 13, wherein said drive means comprises a motor. ### Claim 30 (depends on 25) A sheet feeding apparatus according to claim 25, wherein said drive means comprises a motor. ### Claim 31 (depends on 13) A sheet feeding apparatus according to claim 13, wherein the third convey force is equal to the first convey force. ### Claim 32 A sheet feeding apparatus, comprising: conveying means for applying a conveying force to a sheet; first guide means for guiding the sheet to which the conveying force is applied by said conveying means; second guide means against which a tip end of the sheet guided by said first guide means abuts, for guiding the sheet in a direction changing an advancing direction of the sheet; and control means for controlling said conveying means so that the conveying force of said conveying means is changed from a first convey force to a second convey force larger than the first convey force when a tip end of the sheet that is being guided by said first guide means reaches a first predetermined position upstream of said second guide means without interrupting sheet conveyance, and is changed to a third convey force smaller than the second convey force when the tip end of the sheet that is being guided by said second guide means reaches to a second predetermined position downstream of an abut position where the sheet abuts said second guide means, to thereby feed the sheet to a third predetermined position under the third convey force. ### Claim 33 (depends on 32) A sheet feeding apparatus according to claim 32, wherein said control means changes the convey force by changing a convey speed for said conveying means. ### Claim 34 (depends on 33) A sheet feeding apparatus according to claim 33, wherein said conveying means has a stepping motor. ### Claim 35 (depends on 32) A sheet feeding apparatus according to claim 32, said conveying means has a rotary convey body having an outer peripheral surface in contact with the sheet. ### Claim 36 (depends on 32) A sheet feeding apparatus according to claim 32, wherein said first and second guide means guide the sheet along said conveying means. ### Claim 37 (depends on 35) A sheet feeding apparatus according to claim 35, wherein said second guide means has a press portion pressing the sheet onto said rotary convey body. ### Claim 38 (depends on 32) A sheet feeding apparatus according to claim 32, wherein said conveying means has a drive force transmitting mechanism with a speed reduction ratio. ### Claim 39 (depends on 32) A sheet feeding apparatus according to claim 32, wherein said second guide means has a rotary body pressing the sheet onto said conveying means and rotating following to the sheet conveyed by said conveying means. ### Claim 40 (depends on 32) A sheet feeding apparatus according to claim 32, further comprising record means for recording an image onto the sheet conveyed by said conveying means. ### Claim 41 (depends on 40) A sheet feeding apparatus according to claim 40, wherein said record means has an ink jet head discharging the ink. ### Claim 42 (depends on 41) A sheet feeding apparatus according to claim 41, wherein said ink jet head records the image by the ink discharged by utilizing thermal energy. ### Claim 43 (depends on 32) A sheet feeding apparatus according to claim 32, further comprising image forming means disposed downstream of said second guide means for forming an image to the sheet conveyed by said conveying means. ### Claim 44 A sheet feeding apparatus, comprising: conveying roller for applying a conveying force to a sheet; first guide member for guiding the sheet to which the conveying force is applied by said conveying roller; second guide member against which a tip end of the sheet guided by said first guide member abuts, for guiding the sheet in a direction changing an advancing direction of the sheet; and control portion means for controlling said conveying roller so that the conveying force of said conveying roller is changed from a first convey force to a second convey force larger than the first convey force when a tip end of the sheet is being guided by said first guide member reaches a first predetermined position upstream of said second guide member without interrupting sheet conveyance, and is changed to a third convey force smaller than the second convey force when the tip end of the sheet is being guided by said second guide member reaches to a second predetermined position downstream of an abut position where the sheet abuts said second guide member, to thereby feed the sheet to a third predetermined position under the third convey force. ### Claim 45 (depends on 44) A sheet finding apparatus according to claim 44, wherein said control portion changes the convey force by changing a convey speed for said conveying roller. ### Claim 46 (depends on 45) A sheet feeding apparatus according to claim 45, wherein said conveying roller is driven by a stepping motor. ### Claim 47 (depends on 44) A sheet feeding apparatus according to claim 44, wherein said first and second guide member guide the sheet along said conveying roller. ### Claim 48 (depends on 47) A sheet feeding apparatus according to claim 47, wherein said second guide member has a press portion pressing the sheet onto said conveying roller. ### Claim 49 (depends on 44) A sheet feeding apparatus according to claim 44, further comprising drive means having a drive force transmitting mechanism with a speed reduction ratio for driving said conveying roller. ### Claim 50 (depends on 44) A sheet feeding apparatus according to claim 44, further comprising record means for recording an image onto the sheet conveyed by said conveying roller. ### Claim 51 (depends on 50) A sheet feeding apparatus according to claim 50, wherein said record means has an ink jet head discharging the ink. ### Claim 52 (depends on 51) A sheet feeding apparatus according to claim 51, wherein said ink jet head records the image by the ink discharged by utilizing thermal energy. ### Claim 53 (depends on 44) A sheet feeding apparatus according to claim 44, further comprising image forming means disposed downstream of said second guide means for forming an image to the sheet conveyed by said conveying means.