US20190127166A1 - Image forming apparatus and feeding apparatus - Google Patents

Image forming apparatus and feeding apparatus Download PDF

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Publication number
US20190127166A1
US20190127166A1 US16/165,930 US201816165930A US2019127166A1 US 20190127166 A1 US20190127166 A1 US 20190127166A1 US 201816165930 A US201816165930 A US 201816165930A US 2019127166 A1 US2019127166 A1 US 2019127166A1
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US
United States
Prior art keywords
recording material
feeding
sheet
conveyance
conveyance member
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US16/165,930
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English (en)
Inventor
Junichi Ochi
Yohei Suzuki
Miho Kaiga
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Canon Inc
Original Assignee
Canon Inc
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Filing date
Publication date
Application filed by Canon Inc filed Critical Canon Inc
Assigned to CANON KABUSHIKI KAISHA reassignment CANON KABUSHIKI KAISHA ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KAIGA, MIHO, OCHI, JUNICHI, SUZUKI, YOHEI
Publication of US20190127166A1 publication Critical patent/US20190127166A1/en
Abandoned legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H7/00—Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles
    • B65H7/02—Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles by feelers or detectors
    • B65H7/06—Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles by feelers or detectors responsive to presence of faulty articles or incorrect separation or feed
    • B65H7/12—Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles by feelers or detectors responsive to presence of faulty articles or incorrect separation or feed responsive to double feed or separation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H3/00—Separating articles from piles
    • B65H3/02—Separating articles from piles using friction forces between articles and separator
    • B65H3/06—Rollers or like rotary separators
    • B65H3/0669—Driving devices therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H3/00—Separating articles from piles
    • B65H3/46—Supplementary devices or measures to assist separation or prevent double feed
    • B65H3/52—Friction retainers acting on under or rear side of article being separated
    • B65H3/5207—Non-driven retainers, e.g. movable retainers being moved by the motion of the article
    • B65H3/5215—Non-driven retainers, e.g. movable retainers being moved by the motion of the article the retainers positioned under articles separated from the top of the pile
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H5/00—Feeding articles separated from piles; Feeding articles to machines
    • B65H5/06—Feeding articles separated from piles; Feeding articles to machines by rollers or balls, e.g. between rollers
    • B65H5/062—Feeding articles separated from piles; Feeding articles to machines by rollers or balls, e.g. between rollers between rollers or balls
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H5/00—Feeding articles separated from piles; Feeding articles to machines
    • B65H5/24—Feeding articles in overlapping streams, i.e. by separation of articles from a pile
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H7/00—Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles
    • B65H7/02—Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles by feelers or detectors
    • B65H7/06—Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles by feelers or detectors responsive to presence of faulty articles or incorrect separation or feed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H2403/00—Power transmission; Driving means
    • B65H2403/70—Clutches; Couplings
    • B65H2403/72—Clutches, brakes, e.g. one-way clutch +F204
    • B65H2403/724—Clutches, brakes, e.g. one-way clutch +F204 electromagnetic clutches
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H2403/00—Power transmission; Driving means
    • B65H2403/70—Clutches; Couplings
    • B65H2403/73—Couplings
    • B65H2403/732—Torque limiters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H2511/00—Dimensions; Position; Numbers; Identification; Occurrences
    • B65H2511/50—Occurence
    • B65H2511/52—Defective operating conditions
    • B65H2511/528—Jam
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H2513/00—Dynamic entities; Timing aspects
    • B65H2513/50—Timing
    • B65H2513/512—Starting; Stopping
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H2513/00—Dynamic entities; Timing aspects
    • B65H2513/50—Timing
    • B65H2513/52—Age; Duration; Life time or chronology of event
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H2701/00—Handled material; Storage means
    • B65H2701/10—Handled articles or webs
    • B65H2701/13—Parts concerned of the handled material
    • B65H2701/131—Edges
    • B65H2701/1311—Edges leading edge
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H2701/00—Handled material; Storage means
    • B65H2701/10—Handled articles or webs
    • B65H2701/13—Parts concerned of the handled material
    • B65H2701/131—Edges
    • B65H2701/1313—Edges trailing edge

Definitions

  • the present disclosure relates to an image forming apparatus, such as a copier or a printer, and control of feeding of a recording material in a feeding apparatus used in the image forming apparatus.
  • an image forming apparatus such as a copier or a printer, includes a feeding apparatus that feeds, toward conveyance rollers on a downstream side, a sheet stacked on a stacking portion such as a cassette.
  • a feeding apparatus described in Japanese Patent Laid-Open No. 10-167494, a sheet stacked in the stacking portion is drawn out by a pickup roller.
  • a feed roller and a separation roller separate the plurality of sheets into a preceding sheet and a following sheet on a one-by-one basis.
  • the feeding apparatus is configured such that, when the preceding sheet reaches conveyance rollers on the downstream side from the feed roller, drive of the pickup roller and the feed roller is stopped and the preceding sheet is pulled out by the conveyance rollers. Thus, the following sheet is prevented from being fed toward the downstream side from a separation nip portion formed by the feed roller and the separation roller.
  • FIG. 18A illustrates an enlarged view of a separation nip portion 111 a formed by a feed roller 110 and a separation roller 111 .
  • a preceding sheet S 1 drags a following sheet S 2 and the two sheets are drawn out to the separation nip portion 111 a
  • the following sheet S 2 is not fed toward the downstream side from the separation nip portion 111 a by the aforementioned control.
  • FIG. 18B there is a case where the following sheet S 2 enters a vicinity of the separation nip portion 111 a .
  • FIG. 18C illustrates a state of a cassette at a time point when feeding of the preceding sheet S 1 is completed.
  • the following sheet S 2 may also be drawn out due to influence of friction in some cases.
  • a position of a leading end of the following sheet S 2 varies within a range from an initial position Pa of a leading end of a sheet stacked on the cassette to a position Pb of the separation the nip portion 111 a .
  • a sheet feeding start timing or a sheet feeding speed is set to secure a predetermined sheet interval between sheets (interval between the rear end of the preceding sheet S 1 and the leading end of the following sheet S 2 ), by taking the variation into consideration.
  • a sheet feeding start timing of the following sheet S 2 is set to secure the predetermined sheet interval in a state where the leading end of the following sheet S 2 is at the position Pb, a sheet interval is expanded more than necessary in a state where the leading end of the following sheet S 2 is at the position Pa.
  • productivity the number of sheets subjected to image formation/the number of fed sheets per unit time
  • the disclosure works towards providing an image forming apparatus and a feeding apparatus whose productivity is refined while reducing sudden sound when a rear end of a recording material passes through a separation nip portion.
  • a feeding apparatus includes a feeding member configured to feed a recording material stacked on a stacking portion, a first conveyance member configured to convey the recording material fed by the feeding member, a separation member configured to form a nip portion with the first conveyance member and separate a plurality of recording materials at the nip portion, a second conveyance member configured to convey the recording material conveyed by the first conveyance member, a detection unit configured to be disposed between the first conveyance member and the second conveyance member and to detect the recording material, and a control unit configured to control the feeding member and the first conveyance member so that a first recording material that is stacked on the stacking portion is fed by the feeding member and, after a rear end of the first recording material passes through the feeding member, a second recording material that is stacked on the stacking portion is fed by the feeding member while being partially overlapped with the first recording material and thereby the rear end of the first recording material passes through the nip portion after a leading end of the second recording material
  • FIG. 1 is a sectional view of a printer in Embodiment 1.
  • FIG. 2 illustrates a configuration of a conveyance sensor in Embodiment 1.
  • FIG. 3 is a perspective view illustrating appearance of the printer in Embodiment 1.
  • FIG. 4 is a control block diagram of the printer in Embodiment 1.
  • FIG. 5 is a timing chart of control at a time of sheet feeding in Embodiment 1.
  • FIGS. 6A to 6F are views for explaining a motion of a sheet in Embodiment 1.
  • FIG. 7 is a view for explaining distribution of a position of a leading end of a sheet in Embodiment 1.
  • FIG. 8 is a graph for explaining a positional relation between a preceding sheet and a following sheet in a comparative example.
  • FIG. 9 is a graph for explaining a positional relation between a preceding sheet and a following sheet in Embodiment 1.
  • FIG. 10 is a view illustrating an example of an arrangement position of the conveyance sensor in Embodiment 1.
  • FIGS. 11A and 11B illustrate a flowchart of control at a time of sheet feeding in Embodiment 1.
  • FIG. 12 is a control block diagram of a printer in Embodiment 2.
  • FIG. 13 is a graph for explaining a positional relation between a preceding sheet and a following sheet in Embodiment 2.
  • FIGS. 14A and 14B illustrate a flowchart of control at a time of sheet feeding in Embodiment 2.
  • FIG. 15 is a graph for explaining a positional relation between a preceding sheet and a following sheet in Embodiment 3.
  • FIG. 16 illustrates a configuration of a conveyance sensor in a modification example 1.
  • FIG. 17 illustrates a configuration of a conveyance sensor in a modification example 2.
  • FIGS. 18A to 18C are views for explaining an issue in a related art.
  • FIG. 1 is a sectional view schematically illustrating a full-color laser beam printer 100 (hereinafter, referred to as a printer 100 ) as an example of an image forming apparatus that includes a feeding apparatus in Embodiment 1.
  • a printer 100 a full-color laser beam printer 100
  • the printer 100 includes photosensitive drums 1 , serving as image bearing members, in process cartridges 7 .
  • the process cartridges 7 are provided correspondingly to four colors in total of yellow (Y), magenta (M), cyan (C), and black (B).
  • any one of reference signs (Y, M, C, K) that represent colors is added after a reference sign of a corresponding one of the members to thereby represent a member with a specific color.
  • a photosensitive drum for yellow is represented by 1Y.
  • each of the reference signs (Y, M, C, K) that represent colors is omitted.
  • a charging roller (not illustrated) provided in each of the process cartridges 7 charges a surface of a corresponding one of the photosensitive drums 1 .
  • a laser scanner unit 2 radiates laser light L to each of the photosensitive drums 1 based on image information so that an electrostatic latent image is formed on the photosensitive drum 1 .
  • the latent image formed on the photosensitive drum 1 is visualized with toner by a development roller (not illustrated) which is provided in the process cartridge 7 .
  • toner images of the respective colors that are formed on the photosensitive drums 1 are transferred on an intermediate transfer belt 9 by primary transfer rollers 5 while sequentially being superimposed.
  • the intermediate transfer belt 9 is rotated by a driving roller 8 and a color toner image formed on the intermediate transfer belt 9 is transferred onto a sheet S by a secondary transfer belt 6 .
  • These process members function as image forming units configured to form an image on the sheet S.
  • the feeding apparatus is composed of a cassette 10 and a roller unit 19 .
  • a sheet stacking plate 22 that is a stacking portion on which a plurality of sheets S are stacked is provided.
  • a sheet S is moved up to a drawn-out position by the sheet stacking plate 22 and a sheet (preceding sheet) S that is positioned at the uppermost position is in contact with a pickup roller 15 (hereinafter, referred to as a pick roller 15 ).
  • a pick roller 15 feeds the sheet S 1 among the sheets S stacked on the sheet stacking plate 22 .
  • a feed roller 16 (first conveyance member) further feeds the sheet S 1 fed by the pick roller 15 toward a downstream side.
  • a separation roller 17 (separation member) is fixed to a chassis or the like of the printer 100 via a torque limiter (not illustrated). An operation of the separation roller 17 will be described in detail later.
  • the sheet S 1 fed by the feed roller 16 is conveyed by a pair of registration rollers 3 and 4 (second conveyance member).
  • a conveyance sensor 23 and a top sensor 24 detect the sheet S 1 that is conveyed.
  • the toner image is transferred by the aforementioned secondary transfer roller 6 .
  • a fixing unit 12 fixies the toner image, which is transferred onto the sheet S 1 , on the sheet S 1 with heat and pressure.
  • the sheet S 1 on which the toner image is fixed is discharged to a sheet discharge try 13 by a pair of discharge rollers 11 .
  • FIG. 2 illustrates a configuration of the conveyance sensor 23 in the present embodiment.
  • the conveyance sensor 23 in which a rotation-type sensor arm 30 and a photo-interrupter 31 are combined is used.
  • the sensor arm 30 is configured to be rotatable about a rotation shaft 34 as a center and an arm portion 30 a enters a conveyance path of a sheet S.
  • the arm portion 30 a comes into contact with the sheet S that is conveyed, so that the sensor arm 30 is rotated by passage of the sheet S.
  • a sensor flag 30 b that is integrally provided with the sensor arm 30 is also rotated so that a light transmitting state and a light shielding state of the photo-interrupter 31 are switched.
  • the top sensor 24 also has the same configuration as that of the conveyance sensor 23 .
  • FIG. 3 is a perspective view illustrating appearance of the printer 100 .
  • the cassette 10 is configured to be pullable toward a front surface side of a main body of the apparatus. A user pulls out the cassette 10 and supplies a sheet S for the cassette 10 .
  • a door for jam processing 20 is configured on a side surface side of the main body of the apparatus to be openable/closable. When a sheet S remains in the middle of the conveyance path, that is, when a jam occurs, the user is able to remove the sheet S remaining inside by opening the door for jam processing 20 .
  • an operation panel 29 is provided on the printer 100 . The operation panel 29 provides guidance of each operation to the user through a liquid crystal screen.
  • the operation panel 29 also displays an error or a button or an icon for performing a manual operation. For example, when a jam occurs, based on information of each sensor, it is determined at which part in the apparatus the jam occurs, and how to perform jam processing is notified to the user in an easy-to-understand manner through the operation panel 29 .
  • simple notification by, for example, an LED may be performed without the liquid crystal screen.
  • an LED may be arranged in each of the cassette 10 and the door for jam processing 20 , and the LED to be accessed by the user for the jam processing may be turned on.
  • FIG. 4 is a control block diagram of the printer 100 in the present embodiment.
  • An engine control unit 26 that controls an operation of the printer 100 includes a CPU, a ROM, a RAM, and the like therein and executes processing based on a program stored in the ROM in advance. In FIG. 4 , for example, description related to a process other than a sheet feeding operation, such as an image forming process, is omitted.
  • a motor 27 is connected to the engine control unit 26 .
  • the motor 27 drives and rotates the pick roller 15 and the feed roller 16 through an electromagnetic clutch 28 .
  • the electromagnetic clutch 28 transmits or intercepts driving force of the motor 27 with respect to the pick roller 15 or the feed roller 16 .
  • One-way clutches are built in the pick roller 15 and the feed roller 16 , and when the electromagnetic clutch 28 is turned OFF, the pick roller 15 and the feed roller 16 are brought into a state of being rotatable only in a direction in which a sheet S is fed. Additionally, the motor 27 drives and rotates the pair of the registration rollers 3 and 4 . It is configured that detection results of the conveyance sensor 23 and the top sensor 24 are notified to the engine control unit 26 to display information such as occurrence of a jam on the operation panel 29 .
  • FIG. 5 is a timing chart of control at a time of the sheet feeding and a view schematically illustrating a positional relation between a rear end of a sheet S 1 that is being fed and each of the rollers.
  • the rear end of the sheet S 1 indicates an end of the sheet S 1 on an upstream side in the feeding direction.
  • the engine control unit 26 rotates the pair of the registration rollers 3 and 4 by the motor 27 . Almost at the same time, the engine control unit 26 turns the electromagnetic clutch 28 ON to rotate the pick roller 15 and the feed roller 16 (at a timing when the rear end of the sheet S 1 is at a position d in FIG. 5 ).
  • the sheet S 1 drawn out by the pick roller 15 passes through a separation nip portion 17 a formed by the feed roller 16 and the separation roller 17 and reaches the pair of the registration rollers 3 and 4 .
  • the engine control unit 26 turns the electromagnetic clutch 28 OFF.
  • the rear end of the sheet S 1 does not pass through the pick roller 15 (at a timing when the rear end of the sheet S 1 is at a position e in FIG. 5 ).
  • the pair of the registration rollers 3 and 4 convey the sheet S 1 toward the downstream side so that the sheet S 1 is pulled out from the separation nip portion 17 a .
  • the electromagnetic clutch 28 since the electromagnetic clutch 28 is turned OFF, the driving force from the motor 27 is not transmitted to the pick roller 15 and the feed roller 16 .
  • the two rollers are driven to rotate by following the conveyance of the sheet S 1 by the one-way clutches (not-illustrated). Then, at a timing when a predetermined time has elapsed since the rear end of the sheet S 1 had passed through the pick roller 15 , the engine control unit 26 turns the electromagnetic clutch 28 ON again (at a timing when the rear end of the sheet S 1 is at a position fin FIG. 5 ).
  • the electromagnetic clutch 28 is turned ON again and the pick roller 15 and the feed roller 16 are rotated.
  • a sheet (following sheet) S 2 to be fed next after the sheet S 1 is in contact with the pick roller 15 and is fed.
  • This operation is expressed as “pre-feeding”.
  • the sheet S 1 and the sheet S 2 are conveyed while being partially overlapped.
  • the engine control unit 26 turns the electromagnetic clutch 28 OFF again.
  • a purpose for performing such pre-feeding is to take a countermeasure against sound during conveyance of a sheet, and a content thereof will be described in detail later.
  • the rear end of the sheet S 1 has passed through the separation nip portion 17 a .
  • the leading end of the sheet S 2 does not reach the pair of the registration rollers 3 and 4 . Accordingly, the sheet S 2 is stopped in a state where the electromagnetic clutch 28 is turned OFF. That is, the pick roller 15 and the feed roller 16 are not rotated by the sheet S 2 and stop.
  • the sheet S 1 is conveyed toward a further downstream side by the pair of the registration rollers 3 and 4 , and image formation is performed. As above, the sheet feeding operation of the sheet S 1 ends.
  • the engine control unit 26 calculates a start timing (f in FIG. 5 ) of the pre-feeding operation or an end timing (g in FIG. 5 ) of the pre-feeding operation of the sheet S 2 based on a timing when the sheet S 1 reaches the top sensor 24 .
  • the engine control unit 26 calculates these timings by taking a length of the sheet S 1 and a conveyance speed of the sheet S 1 into consideration.
  • a time lag of responsiveness of the electromagnetic clutch 28 or delay due to a space between driving columns (not illustrated) arises until the pick roller 15 rotates after the electromagnetic clutch 28 is turned ON, so that the engine control unit 26 calculates the timings also by taking the time lag or the delay into consideration.
  • the start timing or the end timing of the pre-feeding operation may be calculated based on a timing when the sheet S 1 reaches the conveyance sensor 23 instead of the top sensor 24 or may be calculated based on a timing when feeding of the sheet S 1 stacked on the cassette 10 is started by the pick roller 15 and the feed roller 16 .
  • the motor 27 may be continuously rotated so that ON and OFF of the electromagnetic clutch 28 are repeatedly switched.
  • the sheet S 2 is moved due to frictional force between the preceding sheet S 1 and the following sheet S 2 (hereinafter, expressed as “being dragged”) in some cases.
  • the sheet S 2 may not be dragged at all, or may be dragged to a position before the separation nip portion 17 a , or may be dragged to the separation nip portion 17 a . Description of being dragged will be given below by using FIGS. 6A to 6F .
  • FIG. 6A illustrates a state where the sheet S 2 is not dragged at all.
  • FIG. 6B illustrates a state where the sheet S 2 is separated from the sheet S 1 at the position before the separation nip portion 17 a and stopped after being slightly dragged.
  • FIG. 6C illustrates a state where the sheet S 2 is separated from the sheet S 1 and stopped at the separation nip portion 17 a after being completely dragged.
  • the electromagnetic clutch 28 is turned OFF.
  • the sheet S 1 is conveyed by the pair of the registration rollers 3 and 4 (not illustrated in FIGS. 6A to 6F ), and the feed roller 16 is driven to rotate by the sheet S 1 .
  • the pick roller 15 that is in contact with the sheet S 2 stops.
  • a position of the leading end of the sheet S 2 advances by a distance F in FIG. 6B and by a distance G in FIG. 6C when FIG. 6A is set as a reference.
  • “being dragged” indicates a phenomenon that the following sheet S 2 is moved due to influence of the friction with the preceding sheet S 1 , that is, a phenomenon that the following sheet S 2 is moved although the following sheet S 2 and the pick roller 15 are not in contact with each other.
  • “pre-feeding” indicates an operation that the following sheet S 2 is moved by a predetermined distance in advance by the pick roller 15 while a feeding operation of the preceding sheet S 1 is performed. That is, in the pre-feeding, the following sheet S 2 and the pick roller 15 are in contact with each other.
  • FIGS. 6D, 6E, and 6F indicate states where pre-feeding of the sheet S 2 is completed after start of the pre-feeding from the states of FIGS. 6A, 6B, and 6C , respectively.
  • amounts of being dragged F and G are maintained as they are and the position of the leading end of the sheet S 2 is moved by the predetermined distance B.
  • the leading end of the sheet S 2 passes through the separation nip portion 17 a in any cases.
  • the separation roller 17 is rotated in the feeding direction of the sheet S 1 .
  • the rotational load of the torque limiter is set to exceed force received by the separation roller 17 due to friction with the three sheets S 1 to S 3 .
  • the rotation of the separation roller 17 is stopped.
  • a purpose of subjecting the sheet S 2 to the pre-feeding after the rear end of the sheet S 1 passes through the pick roller 15 is to reduce sound at a moment when the rear end of the sheet S 1 passes through the separation nip portion 17 a .
  • the countermeasure against the sound will be described below in detail.
  • FIG. 7 illustrates distribution of a position of the leading end of the following sheet S 2 .
  • Distribution of the position of the leading end of the sheet S 2 in a case where the pre-feeding operation is not performed is illustrated in (a) of FIG. 7 .
  • the distribution of the position of the leading end of the sheet S 2 has two peaks at a position j of setting in the cassette 10 and a position m of the separation nip portion 17 a , and frequency thereof is high. Then, frequency at which the leading end of the sheet S 2 is positioned within a range k therebetween is low. In a case of a paper type which is difficult to be dragged, the sheet S 2 is hardly moved due to the influence of the friction with the sheet S 1 .
  • the sheet S 2 is moved due to the influence of the friction with the sheet S 1 , separated from the sheet S 1 by the separation nip portion 17 a , and stopped. Thereby, distribution of the position of the leading end of the sheet S 2 has peaks at two positions.
  • Distribution of the position of the leading end of the sheet S 2 in a case where the pre-feeding operation is performed is illustrated in (b) of FIG. 7 .
  • the distribution of the position of the leading end of the sheet S 2 is shifted to a position advanced by the predetermined distance B to the downstream side of the feeding direction as a whole compared to (a) of FIG. 7 in the case where the pre-feeding operation is not performed.
  • the predetermined distance B by which the sheet S 2 is moved by the pre-feeding operation is set to be longer than a distance A from the position j at which a leading end of a sheet S is set in the cassette 10 to the position m of the separation nip portion 17 a .
  • peaks of the position of the leading end of the sheet S 2 are shifted to a position n and a position o that are on the downstream side of the separation nip portion 17 a . Then, since frequency at which the leading end of the sheet S 2 exists at the position m of the separation nip portion 17 a is low (range p), frequency at which the sudden sound is generated when the rear end of the sheet S 1 being fed passes through the separation nip portion 17 a is low. That is, the sudden sound is able to be reduced.
  • the predetermined distance B by which the sheet S 2 is conveyed by the pre-feeding operation is set to be shorter than a distance D from the separation nip portion 17 a to the pair of the registration rollers 3 and 4 . That is, this may be addressed by satisfying a relation of distance A ⁇ distance B ⁇ distance D.
  • a sheet interval (interval between the rear end of the preceding sheet S 1 and the leading end of the following sheet S 2 ) may be made as short as possible.
  • the sheet interval is set in advance in accordance with a size or a paper type of a sheet S.
  • FIGS. 6D, 6E, and 6F there is a possibility that the position of the leading end of the sheet S 2 varies. The variation should be considered on deciding a feeding timing of the following sheet S 2 .
  • FIG. 8 A graph of a thick solid line indicates the position of the rear end of the sheet S 1 and a graph of a thin solid line indicates the position of the leading end of the sheet S 2 .
  • a case where the position of the leading end of the sheet S 2 is most advanced ( FIG. 6F ) and a case where the position of the leading end of the sheet S 2 is most delayed ( FIG. 6D ) are drawn by two lines, positions of the leading end of the sheet S 2 are all distributed between the aforementioned two lines. As illustrated in FIG.
  • the sheet interval is a sheet interval obtained by adding the distance G to the set sheet interval.
  • the distance G is a distance from an initial position of a leading end of a sheet S stacked on the cassette 10 to the separation nip portion 17 a.
  • the feeding timing of the following sheet S 2 in the present embodiment will be described by using FIG. 9 .
  • the feeding of the sheet S 2 is started at a timing T 4 that is earlier than the timing T 3 illustrated in FIG. 8 so that the sheet interval is shortened.
  • the timing T 4 is calculated from a conveyance speed, a position of the conveyance sensor 23 , or the like.
  • it is most effective in a case where a position of the conveyance sensor 23 is set on the upstream side by a distance G/2 from a position H ( FIG.
  • the sheet interval between the sheet S 1 and the sheet S 2 is a sheet interval obtained by adding the distance G/2 to the set sheet interval, so that variation in the sheet interval is refined by at most G/2 compared to that in the comparative example.
  • a variation amount between a minimum sheet interval and a maximum sheet interval is able to be reduced by G/2 unless restriction of a configuration of the apparatus or the minimum sheet interval to be set is taken into consideration.
  • FIGS. 11A and 11B illustrate a flowchart in which the sheet feeding operation in the present embodiment is summarized.
  • the engine control unit 26 executes control based on the flowchart in FIGS. 11A and 11B based on a program stored in a ROM or the like.
  • the engine control unit 26 determines whether or not a feeding timing of a sheet S from the cassette 10 arrives (S 400 ). When determining that the feeding timing of the sheet S arrives, the engine control unit 26 starts a feeding operation of a sheet S 1 (S 401 ). Specifically, as described above, the engine control unit 26 causes the motor 27 to drive so that the electromagnetic clutch 28 is turned ON. Thereby, the pick roller 15 , the feed roller 16 , and the pair of the registration rollers 3 and 4 are rotated.
  • the engine control unit 26 determines whether or not the conveyance sensor 23 or the top sensor 24 detects the sheet S 1 (S 402 , S 403 ).
  • the engine control unit 26 turns the electromagnetic clutch 28 OFF (S 404 ).
  • the sheet S 1 is conveyed by the pair of the registration rollers 3 and 4 , so that the pick roller 15 and the feed roller 16 are driven by conveyance of the sheet S 1 .
  • the engine control unit 26 determines that the sheet S 1 being fed is a final sheet of a print job (S 405 )
  • the engine control unit 26 stops the motor 27 after the feeding of the sheet S 1 (S 413 ) and ends the sheet feeding operation.
  • the engine control unit 26 proceeds to processing at S 406 .
  • the engine control unit 26 obtains at least a timing when a rear end of the sheet S 1 has passed through the pick roller 15 .
  • the engine control unit 26 determines whether or not a timing when a predetermined time T 1 has elapsed since the top sensor 24 had detected the leading end of the sheet S 1 arrives (S 406 ). In a case where determining that the timing when the predetermined time T 1 has elapsed arrives, the engine control unit 26 turns the electromagnetic clutch 28 ON to start a pre-feeding operation of the sheet S 2 (S 407 ).
  • the engine control unit 26 determines whether or not a timing when the sheet S 2 is conveyed by the predetermined distance B, that is, a timing when a predetermined time T 2 has elapsed since the top sensor 24 had detected the leading end of the sheet S 1 arrives (S 408 ). In a case of determining that the timing when the predetermined time T 2 has elapsed arrives, the engine control unit 26 turns the electromagnetic clutch 28 OFF to end the pre-feeding operation of the sheet S 2 (S 409 ).
  • the position of the leading end of the sheet S 2 at a time point when the pre-feeding operation of the sheet S 2 ends and the feeding of the sheet S 2 is started again varies within the range of the distance G.
  • the conveyance sensor 23 is arranged within the range of the variation and detects presence or absence of the stopped sheet S 2 (S 410 ). In the case where the conveyance sensor 23 detects the sheet S 2 , the leading end of the sheet S 2 is on the downstream side from the conveyance sensor 23 , and in the case where the conveyance sensor 23 does not detect the sheet S 2 , the leading end of the sheet S 2 is on the upstream side from the conveyance sensor 23 .
  • the engine control unit 26 turns the electromagnetic clutch 28 ON at the timing T 3 when a predetermined time has elapsed since the top sensor 24 had detected the leading end of the sheet S 1 (S 411 ). Additionally, in the case where the conveyance sensor 23 does not detect the sheet S 2 , the engine control unit 26 turns the electromagnetic clutch 28 ON at the timing T 4 when a predetermined time has elapsed since the top sensor 24 had detected the leading end of the sheet S 1 (S 412 ).
  • the timing T 4 is earlier than the timing T 3 and is a timing for reducing a variation amount to at most 1 ⁇ 2.
  • processing at 410 by which the conveyance sensor 23 detects presence or absence of the sheet S 2 is executed at a timing after a time required for the rear end of the sheet S 1 to pass through the conveyance sensor 23 has elapsed at least.
  • a start point at which the engine control unit 26 counts the time may be a timing when the conveyance sensor 23 detects the leading end of the sheet S 1 or may be a timing when the top sensor 24 detects the leading end of the sheet S 1 .
  • the engine control unit 26 determines whether or not a threshold time Tth 1 has elapsed since the feeding operation of the sheet S 1 had been started (S 414 ).
  • the threshold time Tth 1 is longer than at least the predetermine time T 1 .
  • the engine control unit 26 displays, on the operation panel 29 provided on the printer 100 , a message indicating that a jam occurs.
  • the engine control unit 26 determines whether or not a timing when a threshold time Tth 2 has elapsed since the conveyance sensor 23 had detected the sheet S 1 arrives (S 416 ). In a case where determining that the timing when the threshold time Tth 2 has elapsed arrives, the engine control unit 26 displays, on the operation panel 29 provided on the printer 100 , a message indicating that a jam occurs. At this time, it is determined that the leading end of the sheet S 1 has passed through the conveyance sensor 23 and stopped at a position not reaching the top sensor 24 , and display is performed on the operation panel 29 to urge opening the door for jam processing 20 to perform jam processing (S 417 ).
  • a conventional apparatus does not include the conveyance sensor 23 as in the present embodiment, it is difficult to determine whether a leading end of a jammed sheet that does not reach the top sensor 24 remains in the cassette 10 or stops in a conveyance path on the upstream side of the top sensor 24 .
  • the configuration in the present embodiment it is possible to guide an appropriate method of jam processing by accurately detecting a jam position without adding a new sensor for detecting a jam. Then, control of the flowchart ends.
  • Embodiment 2 will be described.
  • a difference from Embodiment 1 will be mainly described and description of components similar to those of Embodiment 1 will be omitted.
  • the motor 27 drives the pair of the registration rollers 3 and 4 , the pickup roller 15 , and the feed roller 16 .
  • a motor 37 drives the pair of the registration rollers 3 and 4
  • a motor 36 drives the pickup roller 15 and the feed roller 16 in the present embodiment.
  • the motor 36 is caused to rotate or stop in the present embodiment instead of the operation of turning the electromagnetic clutch 28 ON or OFF in Embodiment 1.
  • the motor 37 may also serve as drive of the photosensitive drum 1 or the like. Other configurations are similar to those in Embodiment 1.
  • the pre-feeding operation of the sheet S 2 is similar to that of Embodiment 1 except for a difference of the electromagnetic clutch and the motor described above.
  • “timing” at which feeding of the sheet S is started is changed by changing a timing when the electromagnetic clutch 28 is turned ON in accordance with a detection result by the conveyance sensor 23 , but in the present embodiment, a “conveyance speed” of the sheet S 2 is changed.
  • FIG. 13 An operation of the present embodiment will be described by using a graph of FIG. 13 .
  • a graph of a thick solid line indicates the position of the rear end of the sheet S 1 and three graphs of thin solid lines each indicate the position of the leading end of the sheet S 2 .
  • the three graphs indicate a case where the position of the leading end of the sheet S 2 is most advanced, a case where the position of the leading end of the sheet S 2 is at a middle position, and a case where the position of the leading end of the sheet S 2 is most delayed.
  • the sheet interval between the sheet S 1 and the sheet S 2 becomes the set sheet interval, so that no special operation is performed.
  • a timing when the leading end of the sheet S 2 reaches the pair of the registration rollers 3 and 4 is set as T 5 .
  • the motor 36 starts rotating at the timing T 3 and the motor 36 is driven so that a conveyance speed of the sheet S 2 by the pick roller 15 and the feed roller 16 is faster than a conveyance speed of the sheet S 1 by the pair of the registration rollers 3 and 4 .
  • the leading end of the sheet S 2 is to reach the pair of the registration rollers 3 and 4 at the timing T 5 .
  • a timing when the leading end of the sheet S 2 reaches the pair of the registration rollers 3 and 4 is T 7 , so that delay occurs.
  • a timing when the leading end of the sheet S 2 reaches the pair of the registration rollers 3 and 4 is T 6 .
  • a timing when the leading end of the sheet S 2 reaches the pair of the registration rollers 3 and 4 is T 8 , so that delay occurs.
  • FIGS. 14A and 14B illustrate a flowchart of the present embodiment.
  • Processing of S 500 to S 510 and S 514 to S 517 is basically the same as the processing of S 400 to S 410 and S 414 to S 417 , which is described in FIGS. 1A and 11B .
  • processing of rotating/stopping the motor 36 at S 504 , S 507 , or S 509 is one obtained by replacing processing of turning the electromagnetic clutch 28 ON/OFF at S 404 , S 407 , or S 409 , respectively.
  • a difference from the flowchart described in FIGS. 11A and 11B lies at S 518 and S 519 .
  • the engine control unit 26 rotates the motor 36 so that the sheet S 2 is conveyed at a normal conveyance speed V 1 (S 518 ).
  • the engine control unit 26 rotates the motor 36 so that the sheet S 2 is conveyed at a conveyance speed V 2 that is faster than the conveyance speed V 1 (S 519 ).
  • the timing when the sheet S 2 reaches the pair of the registration rollers 3 and 4 is made earlier by setting the feeding start timing of the sheet S 2 to be earlier.
  • the timing when the sheet S 2 reaches the pair of the registration rollers 3 and 4 is made earlier by increasing a speed at which the sheet S 2 is conveyed.
  • the present embodiment is effective in a case where a sheet interval that is set in advance is very short and it is therefore difficult to set the feeding start timing of the sheet S 2 to be earlier, for example.
  • Embodiment 3 will be described.
  • a difference from Embodiment 1 and Embodiment 2 will be mainly described and description of components similar to those of Embodiment 1 or Embodiment 2 will be omitted.
  • a configuration of Embodiment 3 is similar to that of Embodiment 2.
  • the pre-feeding operation of the sheet S 2 is similar to that of Embodiment 2.
  • the conveyance speed of the sheet S 2 is changed while changing the feeding start timing of the sheet S 2 depending on a detection result by the conveyance sensor 23 .
  • a difference lies in that, although the conveyance speed of the sheet S 2 is increased in Embodiment 2, the conveyance speed of the sheet S 2 is reduced in the present embodiment.
  • FIG. 15 An operation of the present embodiment will be described by using a graph of FIG. 15 .
  • a graph of a thick solid line indicates the position of the rear end of the sheet S 1 and three graphs of thin solid lines each indicate the position of the leading end of the sheet S 2 .
  • the three graphs indicate a case where the position of the leading end of the sheet S 2 is most advanced, a case where the position of the leading end of the sheet S 2 is at a middle position, and a case where the position of the leading end of the sheet S 2 is most delayed.
  • a graph of a broken line indicates an operation before the control of the present embodiment is applied.
  • timings when the leading end of the sheet S 2 reaches the pair of the registration rollers 3 and 4 in the respective cases are T 5 , T 7 , and T 8 , and there is variation of T 8 to T 5 at maximum.
  • a graph indicated as the middle of the variation indicates a case where the leading end of the sheet S 2 is at the position immediately before the conveyance sensor 23 on the upstream side, specifically, when the motor 36 is stopped. That is, in this case, the conveyance sensor 23 does not detect the stopped sheet S 2 .
  • the feeding start timing of the sheet S 2 is changed from T 3 to T 9 .
  • T 9 is a timing when a timing when the leading end of the sheet S 2 in a case of being most delayed reaches the pair of the registration rollers 3 and 4 is just at T 5 .
  • the feeding start timing of the sheet S 2 is changed to T 9 .
  • the timing of reaching the pair of the registration rollers 3 and 4 is made earlier from T 7 to T 11 as illustrated by a two-dot chain line in FIG. 15 .
  • a rotation speed of the motor 36 is set to be slow by a predetermined amount calculated from time until the conveyance sensor 23 detects the leading end of the sheet S 2 after starting feeding of the sheet S 2 . Thereby, the leading end of the sheet S 2 is to reach the pair of the registration rollers 3 and 4 at the timing T 5 .
  • adjustment of the sheet interval is to be completed before the leading end of the sheet S 2 reaches the pair of the registration rollers 3 and 4 here, but the adjustment of the sheet interval may be completed before the leading end of the sheet S 2 reaches the secondary transfer roller 6 at the latest.
  • a speed of the pair of the registration rollers 3 and 4 also may be set to be variable.
  • the timing when the leading end of the sheet S 2 reaches the pair of the registration rollers 3 and 4 is able to be uniformized to be T 5 .
  • the configuration of the present embodiment makes it possible to minimize or eliminate variation in the sheet interval and is able to be used even when the conveyance speed is not able to be made faster because of an issue, for example, such as a rated performance of the motor 36 or operation sound thereof.
  • the sensor arm 30 is configured to be rotatable about the rotation shaft 34 as a center and the arm portion 30 a enters an inside of a conveyance path of a sheet S.
  • the arm portion 30 a is in contact with the sheet S that is conveyed so that the sensor arm 30 is rotated by passage of the sheet S.
  • the rotary encoder wheel 32 that is integrally formed with the sensor arm 30 is also rotated.
  • a wheel detecting unit 33 is able to detect the rotation angle of the sensor arm 30 based on a rotational amount of the rotary encoder wheel 32 .
  • the rotation angle of the sensor arm 30 becomes larger as a stop position of the sheet S is at a position further on the downstream side. That is, according to the conveyance sensor 35 that has the configuration of FIG. 16 , it is possible to detect the position of the leading end of the sheet S 2 more in detail compared to the conveyance sensor 23 that has the configuration described in FIG. 2 .
  • the engine control unit 26 determines whether or not the conveyance sensor 35 detects the sheet S 2 . In the case where the conveyance sensor 35 detects the sheet S 2 , the engine control unit 26 further obtains the position of the leading end of the sheet S 2 based on the rotation angle of the sensor arm 30 . Then, the engine control unit 26 changes a feeding condition such as the feeding start timing of the sheet S 2 or the feeding speed thereof in accordance with the obtained position of the leading end of the sheet S 2 .
  • the ultrasonic wave sensor 40 includes a transmission unit 38 that transmits an ultrasonic wave and a reception unit 39 that receives the ultrasonic wave transmitted from the transmission unit 38 .
  • the transmission unit 38 and the reception unit 39 are disposed to hold a conveyance path of a sheet S therebetween and the reception unit 39 receives the ultrasonic wave that is attenuated through the sheet S.
  • an amplitude value of the ultrasonic wave received by the reception unit 39 whether or not the sheet S exists between the transmission unit 38 and the reception unit 39 or how many sheets S exist therebetween when the sheet S exists is able to be detected. That is, as illustrated in FIG.
  • the ultrasonic wave sensor 40 is disposed between the separation nip portion 17 a and the pair of the registration rollers 3 and 4 .
  • an ON timing of the electromagnetic clutch 28 or a conveyance speed by the motor 36 is changed depending on whether or not the conveyance sensor 23 detects the sheet S 2 , in Embodiment 1 to Embodiment 3.
  • the position of the leading end of the sheet S 2 is able to be determined even in a state where the sheet S 1 and the sheet S 2 are overlapped.
  • the engine control unit 26 obtains the position of the leading end of the sheet S 2 from a timing when the ultrasonic wave sensor 40 detects the leading end of the sheet S 2 during the pre-feeding and a timing when the electromagnetic clutch 28 is turned OFF or the motor 36 is caused to stop so that the sheet S 2 is temporarily stopped. Then, the engine control unit 26 changes a feeding condition such as the feeding start timing of the sheet S 2 or the feeding speed thereof in accordance with the obtained position of the leading end of the sheet S 2 .
  • the position of the leading end of the sheet S 2 is determined more accurately, so that it is possible to reduce variation in the sheet interval between the sheet S 1 and the sheet S 2 by finely controlling the feeding start timing of the sheet S 2 or the feeding speed thereof.
  • the electromagnetic clutch 28 is turned OFF or the motor 36 is caused to stop for a while before the rear end of the preceding sheet S 1 passes through the pick roller 15 . Then, the electromagnetic clutch 28 is turned ON or the motor 36 is caused to rotate again after the rear end of the preceding sheet S 1 passes through the pick roller 15 .
  • the pick roller 15 and the feed roller 16 may be continuously rotated to perform the pre-feeding operation, without turning the electromagnetic clutch 28 OFF or stopping the motor 36 .
  • Embodiment 3 the configuration of Embodiment 2 (Embodiment 3) may be adopted. That is, the electromagnetic clutch 28 may not be arranged but the motor 36 and the motor 37 may be arranged.
  • the separation roller 17 is used for separating one sheet S from a plurality of sheets S, but there is no limitation thereto.
  • a retard roller by which one sheet S is separated from a plurality of sheets S by rotating in a direction opposite to the feeding direction of the sheet S may be used.
  • Embodiment 1 to Embodiment 3 described above the description has been given by using a feeding apparatus that is provided in the printer 100 in a fixed manner. But there is no limitation thereto.
  • the disclosure may be applied to an optional sheet feeding apparatus that is detachably attachable to the printer 100 .
  • the optional sheet feeding apparatus includes a control unit and has a configuration similar to the block diagram described in FIG. 4 . It may be configured that the optional sheet feeding apparatus is not mounted with the control unit, and the engine control unit 26 of a side of the printer 100 performs control of each roller provided in the optional sheet feeding apparatus.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Sheets, Magazines, And Separation Thereof (AREA)
  • Paper Feeding For Electrophotography (AREA)
  • Controlling Sheets Or Webs (AREA)
  • Delivering By Means Of Belts And Rollers (AREA)
US16/165,930 2017-10-27 2018-10-19 Image forming apparatus and feeding apparatus Abandoned US20190127166A1 (en)

Applications Claiming Priority (2)

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JP2017-207963 2017-10-27
JP2017207963A JP2019077554A (ja) 2017-10-27 2017-10-27 画像形成装置及び給送装置

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20190233234A1 (en) * 2016-04-28 2019-08-01 Canon Kabushiki Kaisha Image forming apparatus and feeding apparatus
US20190248614A1 (en) * 2018-02-13 2019-08-15 Canon Kabushiki Kaisha Sheet feeding apparatus and image forming apparatus
US20190306354A1 (en) * 2018-03-28 2019-10-03 Brother Kogyo Kabushiki Kaisha Sheet Conveyor
US11459195B2 (en) * 2020-02-06 2022-10-04 Canon Kabushiki Kaisha Original reading apparatus

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US7690650B2 (en) * 2006-11-09 2010-04-06 Sharp Kabushiki Kaisha Sheet transporting device, and automatic document feeder and image forming apparatus provided with the same
US9027925B2 (en) * 2013-04-30 2015-05-12 Lexmark International, Inc. Methods for feeding media sheets having increased throughput
US9340383B2 (en) * 2014-06-19 2016-05-17 Konica Minolta, Inc. Image forming apparatus
US10447875B2 (en) * 2014-03-10 2019-10-15 Canon Kabushiki Kaisha Printing apparatus, method and storage medium for conveying sheets intermittently to printhead while forming overlaps state

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Publication number Priority date Publication date Assignee Title
US7690650B2 (en) * 2006-11-09 2010-04-06 Sharp Kabushiki Kaisha Sheet transporting device, and automatic document feeder and image forming apparatus provided with the same
US9027925B2 (en) * 2013-04-30 2015-05-12 Lexmark International, Inc. Methods for feeding media sheets having increased throughput
US10447875B2 (en) * 2014-03-10 2019-10-15 Canon Kabushiki Kaisha Printing apparatus, method and storage medium for conveying sheets intermittently to printhead while forming overlaps state
US9340383B2 (en) * 2014-06-19 2016-05-17 Konica Minolta, Inc. Image forming apparatus

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20190233234A1 (en) * 2016-04-28 2019-08-01 Canon Kabushiki Kaisha Image forming apparatus and feeding apparatus
US10562724B2 (en) 2016-04-28 2020-02-18 Canon Kabushiki Kaisha Image forming apparatus and feeding apparatus
US10654674B2 (en) * 2016-04-28 2020-05-19 Canon Kabushiki Kaisha Image forming apparatus and feeding apparatus
US20190248614A1 (en) * 2018-02-13 2019-08-15 Canon Kabushiki Kaisha Sheet feeding apparatus and image forming apparatus
US10981738B2 (en) * 2018-02-13 2021-04-20 Canon Kabushiki Kaisha Sheet feeding apparatus and image forming apparatus
US20190306354A1 (en) * 2018-03-28 2019-10-03 Brother Kogyo Kabushiki Kaisha Sheet Conveyor
US10666824B2 (en) * 2018-03-28 2020-05-26 Brother Kogyo Kabushiki Kaisha Sheet conveyor
US11459195B2 (en) * 2020-02-06 2022-10-04 Canon Kabushiki Kaisha Original reading apparatus

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