EP0762227A2 - Dispositif d'alimentation en feuilles - Google Patents

Dispositif d'alimentation en feuilles Download PDF

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Publication number
EP0762227A2
EP0762227A2 EP96306202A EP96306202A EP0762227A2 EP 0762227 A2 EP0762227 A2 EP 0762227A2 EP 96306202 A EP96306202 A EP 96306202A EP 96306202 A EP96306202 A EP 96306202A EP 0762227 A2 EP0762227 A2 EP 0762227A2
Authority
EP
European Patent Office
Prior art keywords
sheet
stack
leading
trailing
vacuum plenum
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.)
Withdrawn
Application number
EP96306202A
Other languages
German (de)
English (en)
Other versions
EP0762227A3 (fr
Inventor
Kenneth P. Moore
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.)
Xerox Corp
Original Assignee
Xerox Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Xerox Corp filed Critical Xerox Corp
Publication of EP0762227A2 publication Critical patent/EP0762227A2/fr
Publication of EP0762227A3 publication Critical patent/EP0762227A3/fr
Withdrawn legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/65—Apparatus which relate to the handling of copy material
    • G03G15/6502—Supplying of sheet copy material; Cassettes therefor
    • G03G15/6511—Feeding devices for picking up or separation of copy sheets
    • 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
    • B65H3/08—Separating articles from piles using pneumatic force
    • B65H3/0808—Suction grippers
    • B65H3/0816—Suction grippers separating from the top of 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
    • B65H3/00—Separating articles from piles
    • B65H3/46—Supplementary devices or measures to assist separation or prevent double feed
    • B65H3/48—Air blast acting on edges of, or under, articles

Definitions

  • This invention relates to an electrophotographic printing machine, and more particularly concerns an apparatus for advancing sheets from a stack to processing stations within the printing machine.
  • a typical electrophotographic printing machine employs a photoconductive member that is charged to a substantially uniform potential so as to sensitize the surface thereof.
  • the charged portion of the photoconductive member is exposed to a light image of an original document being reproduced.
  • Exposure of the charged photoconductive member selectively dissipates the charge thereon in the irradiated areas to record an electrostatic latent image on the photoconductive member corresponding to the informational areas contained in the original document.
  • the latent image is developed by bringing a developer material into contact therewith.
  • the electrostatic latent image is developed with dry developer material having carrier granules with toner particles adhering triboelectrically thereto.
  • a liquid developer material may be used as well.
  • the toner particles are attracted to the latent image forming a visible image on the photoconductive surface.
  • the toner image is transferred to a sheet.
  • the toner image is then heated to permanently fuse it to the sheet.
  • a sheet feeder In either a monocolor or multicolor printing machine, it is necessary for a sheet feeder to advance cut copy sheets to the processing stations of the printing machine in a rapid, dependable manner.
  • This sheet feeder may be used in a document handling system for advancing original documents to a platen of a copier for subsequent reproduction thereat.
  • this sheet feeder may be used to advance successive sheets to the transfer station of the printing machine in order to receive the monocolor or multicolor toner image from the photoconductive member thereat.
  • These sheet feeders must operate flawlessly to virtually eliminate the risk of damaging the sheets and generate minimum machine shutdowns due to uncorrectable misfeeds or sheet multifeeds.
  • An air knife is located at the leading edge of the stack to inject air between the acquired sheet and the remainder of the stack to separate the acquired sheet, i.e. the top sheet, from the remainder of the stack. After the top sheet is separated, the vacuum pulls the separated sheet up and acquires it. Following acquisition, the belt transport advances the sheet from the stack of sheets.
  • Various types of sheet feeders have been employed heretofore.
  • US-A-4 451 028 discloses a sheet feeding apparatus with a rear vacuum plenum for acquiring the trailing portion of the sheet.
  • a front vacuum plenum is positioned over the leading portion of the sheet and adapted to acquire the leading portion of the sheet.
  • a sheet transport is associated with the vacuum plenum to advance the acquired sheet in a forward direction.
  • An air knife is located at the trailing edge of the sheet to inject air between the trailing edge of the top sheet of the stack and the remainder of the stack.
  • apparatus for advancing sheets from a stack thereof, the apparatus including: a movable guide adapted to be positioned in engagement with an edge of the stack to align the sheets thereof; a trailing vacuum plenum positioned over the stack and adapted to acquire a trailing portion of a sheet; a leading vacuum plenum positioned over the stack and adapted to acquire a leading portion of the sheet; air supply means for injecting air between at least one sheet and the remainder of the stack; and a sheet transport positioned to advance the sheet acquired by the leading vacuum plenum to advance the sheet from the stack; characterised in that the trailing vacuum plenum is associated with the guide to move in unison therewith; and in that the air supply means injects air between at least the trailing portion of the sheet and the stack, and the leading portion of sheet and the stack.
  • a printing machine of a type having a sheet advancing from a stack thereof including a surface; forming means for forming a visible image on the surface; and transferring means for transferring the visible image from the surface to a sheet, characterised in that the printing machine includes apparatus for advancing sheets from a stack as described above.
  • FIG. 2 there is shown a multicolor electrophotographic printing machine using the sheet feeding apparatus of the present invention.
  • the printing machine employs a photoconductive belt 10 supported by a plurality of rollers or bars 12.
  • Photoconductive belt 10 is arranged in a vertical orientation and advances in the direction of arrow 14. Successive portions of the photoconductive surface of belt 10 advance sequentially to the various processing stations disposed about the path of movement thereof.
  • belt 10 passes through charging station 16.
  • a corona generating device (not shown) charges the photoconductive surface of belt 10 to a relatively high, substantially uniform potential. After the photoconductive surface of belt 10 is charged, the charged portion thereof is advanced to the exposure station.
  • an imaging beam generated by a raster output scanner (ROS) 20 creates a color separated electrostatic latent image on the photoconductive surface of belt 10.
  • ROS raster output scanner
  • This color separated electrostatic latent image is developed by developer unit 22.
  • Developer unit 22 deposits black toner particles on the electrostatic latent image. In this way, a black toner powder image is formed on the photoconductive surface of belt 10. After the black toner powder image has been developed on the photoconductive surface of belt 10, belt 10 continues to advance in the direction of arrow 14 to a recharge station.
  • a corona generating device 56 recharges the photoconductive surface to a relatively high, substantially uniform potential.
  • a different imaging beam 18 Y from ROS 20 selectively dissipates the charge to record another partial electrostatic latent image on the photoconductive surface of belt 10 corresponding to the regions to be developed with yellow toner particles.
  • This partial electrostatic latent image is now advanced to the next successive developer unit 50.
  • Developer unit 50 deposits yellow toner particles on the photoconductive surface of belt 10 to form a yellow toner powder image thereon. After the electrostatic latent image has been developed with the yellow toner, belt 10 advances in the direction of arrow 14 to the next recharge station.
  • a corona generating device 58 charges the photoconductive surface of belt 10 to a relatively high, substantially uniform potential.
  • another imaging beam 18 M from ROS 20 selectively discharges the charge on the photoconductive surface to record a partial electrostatic latent image for development with magenta toner particles.
  • belt 10 advances the latent image to the magenta developer unit 52.
  • Magenta developer unit 52 deposits magenta toner particles on the latent image. These toner particles may be in partially superimposed registration with the previously formed yellow toner powder image. After the magenta toner powder image is formed on the photoconductive surface of belt 10, belt 10 advances to the next recharge station.
  • corona generator 60 recharges the photoconductive surface of belt 10 to a relatively high, substantially uniform potential.
  • Another imaging beam 18 C from ROS 20 selectively discharges those portions of the charged photoconductive surface which are to be developed with cyan toner particles.
  • the latent image to be developed with cyan toner particles is advanced to cyan developer unit 54.
  • Cyan developer unit 54 deposits cyan particles on the latent image recorded on the photoconductive surface of belt 10. These cyan toner particles form a cyan toner powder image which may be partially or totally in superimposed registration with the previously formed yellow and magenta toner powder images. In this way, a multicolor toner powder is formed on the photoconductive surface of belt 10.
  • belt 10 advances the multicolor toner powder image to transfer station 24.
  • Sheet feeding apparatus 70 includes a trail vacuum plenum 84, a lead vacuum plenum 104 and sheet feeding plate 106.
  • Stack 32 is supported by tray 76.
  • a trail edge guide 78 is mounted movable on tray 76. Trail edge guide 78 engages the trailing edge of the stack of sheets to align the sheets of stack 32.
  • Trail vacuum plenum 84 is mounted on guide 78 and moves in unison therewith.
  • trail vacuum plenum 84 may be associated with guide 78 to move in unison therewith.
  • trail vacuum plenum 84 may be coupled to guide 78 by belts or gears to move in unison therewith.
  • Tray 76 is mounted on an elevator system (not shown) and adapted to move in a vertical direction so as to position the topmost sheet of stack 32 adjacent the trailing vacuum plenum 84 and the lead vacuum plenum 104 and feeding plate 106.
  • Sheet feeding apparatus 70 will be described hereinafter in greater detail with reference to Figure 1.
  • the topmost sheet is advanced by forwarding rollers 82 to transfer station 24.
  • a corona generating device sprays ions onto the backside of the sheet. This attracts the developed multicolor image from the photoconductive surface of belt 10 to the sheet.
  • a vacuum transport (not shown) moves the sheet in the direction of arrow 36 to fusing station 38.
  • Fusing station 38 includes fuser roll 40 and a backup roll 42.
  • the backup roll 42 is resiliently urged into engagement with the fuser roll 40 to form a nip through which the sheet passes.
  • the toner particles coalesce with one another and bond to the sheet in image configuration forming a multicolor image thereon.
  • the finished sheet is discharged to a finishing station 44 where the sheets are compiled and formed into sets which may be bound to one another. These sets are advanced to a catch tray 46 for subsequent removal therefrom by the printing machine operator.
  • multicolor developed image has been disclosed as being transferred to a sheet of support material, e.g. paper, it may be transferred to an intermediate member, such a belt or drum, and then, subsequently transferred and fused to the sheet of support material.
  • an intermediate member such as a belt or drum
  • toner powder images and toner particles have been disclosed herein, one skilled in the art will appreciate that a liquid developer material may also be used.
  • Sheet feeding apparatus 70 may be installed adjacent to the exposure platen of a conventional printing machine for feeding of documents to the platen for copying.
  • the sheet feeding apparatus may be mounted at the beginning of the sheet path for advancing cut sheets to the transfer station of the printing machine.
  • the sheet feeding apparatus illustrated is merely one example of a sheet feeder which may be used according to the present invention.
  • Sheet feeding apparatus 70 is provided with a sheet stack supporting tray 76 which may be raised and lowered through electrical power screws by a motor (not shown) from a base support platform (also not shown).
  • the motor is activated to move the sheet stack support tray 76 vertically upward by a stack height sensor (not shown) when the level of the sheet relative to the sensor falls beneath a predetermined level.
  • the motor is inactivated by the stack height sensor when the level of the sheets relative to the sensor is above the predetermined level.
  • the stack height sensor may be located at the rear or at a side of the stack of sheets to sense a height level. In this way, the level of the top sheet of the stack of sheets may be maintained within narrow limits to assure proper sheet separation, acquisition and feeding.
  • the sheet feeding apparatus has both a leading and a trailing vacuum plenum arrangement to perform separation functions.
  • the leading vacuum plenum 104 and the trailing vacuum plenum 84 are supplied with low air pressure through conduit system 72 by vacuum pump 90.
  • Pump 90 is connected to conduit 86 which, in turn, is connected to conduit 88.
  • Conduit 88 is connected to vacuum plenums 84 and 104.
  • pump 90 When pump 90 is actuated, air is pulled from both the leading and trailing vacuum plenums through the pump 90 to an exhaust (not shown).
  • a valve (not shown) is placed in the portion of air conduit 88 supplying the leading vacuum plenum 104.
  • the leading vacuum plenum 104 has associated therewith a slide plate transport assembly 106 for advancing the top sheet in the stack from the remainder of the stack.
  • the surface 92 of trailing vacuum plenum 84 adjacent the topmost sheet is made from low friction material to reduce the friction between the trailing vacuum plenum 84 and the topmost sheet.
  • Trailing vacuum plenum 84 is mounted on guide 78.
  • Guide 78 is mounted movably on tray 76.
  • Guide 78 is moved into position in contact with the trailing edge of the stack 32 of sheets to align the sheets thereof. In this way, as guide 78 moves with respect to tray 76, trailing vacuum plenum 84 moves in unison therewith. This permits different sizes of stacks of sheets to be supported by tray 76 with the trailing vacuum plenum 84 properly positioned relative to the trailing portion of the uppermost sheet of the stack 32.
  • Rear fluffer jets 94 are mounted on guide 78 to move in unison therewith as well.
  • the rear fluffer jets 94 have at least two nozzles (not shown) directed to the rear or trailing edge of the top sheet in the stack 32 of sheets to be fed.
  • the rear fluffer jets serve to direct a blast of air at the trailing edge of the sheets to separate the trailing portion of several sheets from the remainder of the stack by inserting a volume of air therebetween.
  • Leading fluffer jets 96 and air knife 102 direct a blast of air at the leading edge of the sheets to separate the leading portion of several sheets from the remainder of the stack by inserting a volume of air therebetween. This facilitates acquisition of the topmost sheet by plenum 104.
  • tray 76 is elevated by power screws and advances the topmost sheet to the sheet feeding level.
  • Vacuum pump 90 is activated and continuously exhaust air from conduits from 86 and 88.
  • the portion of conduit 88 connected to plenum 104 is periodically closed by a valve (not shown) therein.
  • the rear fluffer jets 94, leading fluffer jets 96 and air knife 102 are activated to inject air between the top sheets and the remainder of the stack 32. This serves to separate the top sheets from the remainder of the stack 32.
  • the trailing portion of the top sheet is acquired by the trailing vacuum plenum 92. With the valve (not shown) in conduit 88 open, the front of the topmost sheet is acquired by leading vacuum plenum 104.
  • Slide plate assembly 106 is energized and the top sheet, which has been acquired by the vacuum plenums, is driven forward in the direction of arrow 100 from stack 32.
  • Surface 92 of rear plenum 84 has a low coefficient of friction.
  • slide plate assembly 106 include a slide plates having a high coefficient of friction. In this way, the frictional driving force exerted on the leading portion of the sheet by the vacuum and by the slide plate transport assembly 106 is greater than the drag exerted on the rear portion of the sheet by the trailing vacuum plenum 84.
  • the rear fluffer jets 94, leading fluffer jets 96, air knife 102 and rear vacuum plenum 84 are constantly energized, while the leading vacuum plenum 104 and slide plate transport assembly 106 are pulsed for each sheet that is fed to insure an intercopy gap between the sheets being fed and to avoid the possibility of sheets shingling. Further details of this type of system are discussed in US-A- 4 451 028.
  • the present invention is directed to a sheet feeding apparatus wherein a trailing vacuum plenum, positioned over a stack of sheets, is adapted to acquire a trailing portion of the uppermost sheet of the stack.
  • the trailing vacuum plenum is associated with a movable guide.
  • the movable guide aligns the sheets of the stack. In this way, the guide and trailing vacuum plenum move in unison with one another.
  • a leading vacuum plenum, positioned over the stack is adapted to acquire the leading portion of the sheet.
  • a sheet transport advances the sheet acquired by the leading vacuum plenum.
  • the sheet is advanced from the stack to a processing station in the printing machine.
  • the processing station may be a transfer station when cut sheets are being advanced by the sheet feeder for receiving information thereon, or a document handler for advancing sheets to the exposure platen of a copier.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Sheets, Magazines, And Separation Thereof (AREA)
EP96306202A 1995-09-11 1996-08-27 Dispositif d'alimentation en feuilles Withdrawn EP0762227A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US52646995A 1995-09-11 1995-09-11
US526469 1995-09-11

Publications (2)

Publication Number Publication Date
EP0762227A2 true EP0762227A2 (fr) 1997-03-12
EP0762227A3 EP0762227A3 (fr) 1997-06-11

Family

ID=24097480

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96306202A Withdrawn EP0762227A3 (fr) 1995-09-11 1996-08-27 Dispositif d'alimentation en feuilles

Country Status (4)

Country Link
EP (1) EP0762227A3 (fr)
JP (1) JPH09124171A (fr)
BR (1) BR9603718A (fr)
MX (1) MX9603676A (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL1007943C2 (nl) * 1997-12-31 1999-07-01 Hadewe Bv Inrichting en werkwijze voor het van een stapel separeren van vellen.
CN111806816A (zh) * 2019-04-12 2020-10-23 苏州维旺科技有限公司 一种双面撕膜设备
US20230312278A1 (en) * 2022-03-29 2023-10-05 Fujifilm Business Innovation Corp. Medium feeding device and medium processing device including the same

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4931718B2 (ja) * 2007-07-23 2012-05-16 株式会社リコー シート材給送装置、画像形成装置
JP5203819B2 (ja) * 2008-07-04 2013-06-05 株式会社東芝 紙葉類取り出し装置
JP2014169182A (ja) * 2013-02-08 2014-09-18 Ricoh Co Ltd 給紙装置、および画像形成装置

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1718581A (en) * 1927-11-03 1929-06-25 Rockstroh Walter Sheet-feeding device with sheet separation by a blast of air
CH479474A (fr) * 1967-09-25 1969-10-15 Miller Printing Machinery Co Appareil d'alimentation en feuilles à partir d'une pile de feuilles
US4451028A (en) * 1981-11-27 1984-05-29 Xerox Corporation Sheet feeding apparatus
EP0272153A2 (fr) * 1986-12-19 1988-06-22 Xerox Corporation Dispositif d'alimentation en feuilles
US5150892A (en) * 1990-03-30 1992-09-29 Minolta Camera Kabushiki Kaisha Sheet feeding apparatus

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1718581A (en) * 1927-11-03 1929-06-25 Rockstroh Walter Sheet-feeding device with sheet separation by a blast of air
CH479474A (fr) * 1967-09-25 1969-10-15 Miller Printing Machinery Co Appareil d'alimentation en feuilles à partir d'une pile de feuilles
US4451028A (en) * 1981-11-27 1984-05-29 Xerox Corporation Sheet feeding apparatus
EP0272153A2 (fr) * 1986-12-19 1988-06-22 Xerox Corporation Dispositif d'alimentation en feuilles
US5150892A (en) * 1990-03-30 1992-09-29 Minolta Camera Kabushiki Kaisha Sheet feeding apparatus

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL1007943C2 (nl) * 1997-12-31 1999-07-01 Hadewe Bv Inrichting en werkwijze voor het van een stapel separeren van vellen.
EP0927692A1 (fr) * 1997-12-31 1999-07-07 Neopost B.V. Dispositif pour séparer des feuilles d'une pile de feuilles
CN111806816A (zh) * 2019-04-12 2020-10-23 苏州维旺科技有限公司 一种双面撕膜设备
US20230312278A1 (en) * 2022-03-29 2023-10-05 Fujifilm Business Innovation Corp. Medium feeding device and medium processing device including the same

Also Published As

Publication number Publication date
BR9603718A (pt) 1998-05-26
JPH09124171A (ja) 1997-05-13
EP0762227A3 (fr) 1997-06-11
MX9603676A (es) 1997-03-29

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