US3649115A - Pick off means for an electrostatic reproduction device - Google Patents

Pick off means for an electrostatic reproduction device Download PDF

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Publication number
US3649115A
US3649115A US861508A US3649115DA US3649115A US 3649115 A US3649115 A US 3649115A US 861508 A US861508 A US 861508A US 3649115D A US3649115D A US 3649115DA US 3649115 A US3649115 A US 3649115A
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United States
Prior art keywords
copy sheet
pickoff
imaging surface
leading portion
copy
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.)
Expired - Lifetime
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US861508A
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English (en)
Inventor
Howard T Hodges
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Eastman Kodak Co
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Eastman Kodak Co
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Publication date
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    • 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
    • G03G15/6532—Removing a copy sheet form a xerographic drum, band or plate
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S271/00—Sheet feeding or delivering
    • Y10S271/90—Stripper

Definitions

  • Copy sheets are fed into transfer contact with the section with a leading portion extending over the recess and a deflector is moved into and out of 'the recess to pick off the copy sheet.
  • Alternative separating structure is provided to urge the copy sheet away from the pickoff member to avoid damage to the copy sheet 1mage.
  • one form of electrophotography comprises the following basic steps: (a) uniformly electrostatically charging the photoconductive surface of an electrophotosensitive element; (b) imagewise exposing the photoconductive surface to a light pattern, thereby selectively dissipating. the uniform charge to form an electrostatic image of the original copy thereon; (c) applying toner to the photoconductive surface to form a toner image defined by the electrostatic image; (d) transferring the toner image from the photoconductive surface to a copy sheet; and (e) permanently fixing the toner image to the copy sheet.
  • the electrophotosensitive element may be repetitively cycled through the electrophotographic copying process, each time transferring to a copy sheet the toner image formed on the photoconductive surface thereof.
  • the toner image transfer step is usually accomplished by advancing the copy sheet and the toner-bearing surface of the electrophotosensitive element, in contiguous relationship, past a transfer station which comprises means for electrostatically charging the copy sheet to a polarity to attract the toner image thereto.
  • a transfer station which comprises means for electrostatically charging the copy sheet to a polarity to attract the toner image thereto.
  • apparatus is pro,- vided for overcoming the aforementioned separation difficulty of the prior art.
  • the conventional closed-loop configuration of the electrophotosensitive element is replaced by-a noncontinuous arcuately shaped element having leading and trailing edges, and means are provided for laying down a copy sheet on the photoconductive surface of the element insuch a manner that the leading edge of the copy sheet extends forwardof the leading edge of the electrophotosensitive element, thereby providing a readily engageable flap which may be engaged by a simple mechanical pickoff member and guided away from the direction of travel of the electrophotosensitive element.
  • Means are also provided for synchronizing the action of the mechanical pickoff member with the passage of the leading edge of the copy sheet therepast, thereby assuring that the mechanical member contacts only the copy sheet, leaving the delicate photoconductive surface untouched.
  • FIG. 1 is a partial diagrammatic side elevation of a preferred automatic electrophotographic copier of the invention
  • FIG. 2 is a fragmentary front elevation, takenalong. line 2- 2 of FIG. 1, showing a copy sheet advancing and pickoff mechanism with portions omitted for clarity of illustration;
  • FIG. 3 is a fragmentary, diagrammatic, side. elevation of an alternative pickoff means for deflecting the copy sheet away from the electrophotosensitive element, which. includes a vacuum roller;
  • FIG. 4 is a fragmentary, diagrammatic, side elevation of a further alternative pickoff means utilizing a corona discharge device
  • FIG. 5 is a fragmentary, diagrammatic, side elevation of a still further alternative pickoff means utilizing a mohair brush.
  • FIG. 6 is a fragmentary, diagrammatic, side elevation of a still further alternative pickoff means utilizing an air emission source.
  • an automatic electrophotographic copying machine for making a hard copy of the pattern la formed on the original copy 1.
  • the machine includes the following elements: a noncontinuous and arcuately shaped electrophotosensitive element 10; drive means 20 for advancing element 10 in a substantially circular path whereby element 10 is continuously recycled through the electrophotographic copying process; a charging station 25 whereby the surface of element 10 may be uniformly electrostatically charged; an exposure station 30 where an image of light pattern Ia may be focused on the surface of element 10 so as to selectively dissipate the charge thereon, leaving behind an electrostatic image corresponding to light pattern Ia; a developing station 35 whereby the electrostatic image so formed is made visible with toner particles;
  • a transfer station 40 whereby the toner image formed on element 10 may be transferred to the surface of a copy sheet 55; a copy sheet advancing mechanism 90 for advancing copy sheet 55 from a stack 56 of such sheets to transfer station 40 in timed-relationship with the arrival of element 10 thereat; pickoff means 75 for engaging the leading edge 55a of copy sheet 55 and guiding it away from the direction of travel of element 10; and fusing station 45 for permanently fixing the transferred toner image on the copy sheet 55.
  • the machine also includes a projection station which serves to illuminate original 1 and project the image thereof on element as the latter passes exposure station 30. and means for advancing original 1 into the projection station at the same linear rate as that at which element 10 is advanced by drive means and in synchronism with the passage of element 10 past exposure station 30.
  • the machine includes a cleaning station 50 which merely serves to remove nontransferred toner particles from the surface ofelement 10.
  • Electrophotosensitive element 10 is preferably comprised of an arcuate transparent support plate 11 (e.g., ordinary glass or clear plastic) having a multilayer web 12 stretched across the entire longitudinal dimension thereof. Secured to the leading edge 11a and trailing edge 11b of plate 11 is a pair of resilient pads 16 which prevent a sharp bending of web 12 as it is stretched over these edges.
  • Web 12 is preferably comprised of a transparent conductive layer 13 having disposed thereon a photoconductive insulating layer 14. It is, of course, the outer surface of the photoconductive insulating layer 14 which is electrostatically charged, imagewise exposed and developed during the copying process.
  • transparent materials for plate 11 and the conductive layer 13 of web 12 it is possible to expose the photoconductive layer 14 through the base (i.e., from the concave side of element 10) and eliminate the necessity of cleaning station 50 which serves merely to remove nontransferred toner from the photoconductive surface of element 10 which would interfere with exposure from the opposite side.
  • Suitable transparent conductive materials are disclosed in U.S. Pat. No. 3,245,833, to D. J. Trevoy.
  • Suitable photoconductive materials and processes for their manufacture are disclosed in U.S. Pat. No. 3,l4l,770, to D. R. Davis et al.
  • Arcuate support plate 11 is laterally supported along the edges thereof by a pair of circular spaced rims 60 and 61, as in FIG. 2. Each rim is rigidly mounted on a rotatable drive shaft 21, as by a plurality of spoke members (not shown). Shaft 21 is driven by drive means 20, such as an electric motor. Suspended from rims 60 and 61 adjacent the trailing edge 11b of plate 11, and extending toward shaft 21, is a pair of spaced support members 63 and 64 between which is rotatably mounted a supply reel 65, whereon a fresh multilayer web 12 may be wound.
  • a second pair of spaced support members 67 between which is rotatably mounted a takeup reel 68 whereon web 12 may be wound whenever replacement of the web is deemed desirable.
  • Suitable apparatus is provided for advancing web 12 from the supply reel 65, along the surface of plate 11, to takeup reel 68. Such web advancing apparatus is more fully described in the copending, commonly assigned application, U.S. Ser. No. 777,717 to Howard T. Hodges, filed Nov. 21, 1968, now abandoned.
  • Projection station 5 is comprised of platens 6, 60; light sources 7, 7a; a 45 reflector or mirror 8; and a lens system 9.
  • Platen 6 is transparent so as to permit light pattern 1a to be illuminated by light sources 7, 7a.
  • Reflector 8 and lens system 9 serve to form an image of pattern 1a on the photoconductive layer 14 of element 10 as the latter passes exposure station 30.
  • the amount of exposure at station 30 is controllable by varying the rate at which element 10 advanced or by varying the intensity of light sources 7, 7a or by varying the aperture of lens system 9 or a combination of these.
  • Synchronization of the rate at which the original copy 1 is advanced through projection station 5 with the rate at which element 10 passes exposure station 30 is accomplished by a timing belt 2 which is arranged to ride in a I groove 60a formed on the periphery of rim 60 (shown in FIG. 2) and over rotatable shafts upon which nip roller 3 and 4 are mounted.
  • the copy sheet or receiver advancing mechanism includes a cam 91, disc 95, drive belt 93, nip roller 100, 101 and friction wheel 105.
  • Cam 91, mounted for rotation with drive shaft 21, is substantially sector-shaped, having two plane surfaces 91a and 91b extending radially from drive shaft 21 and an arcuate surface 91c connecting the outer terminators of the plane surfaces 910 and b.
  • Disc 95 is secured to a shaft 96 which, in turn, is mounted for rotation on the free end of a lever 97.
  • the opposite end of lever 97 is pivotally mounted to the machine housing by pin 98.
  • Spring means 99 is provided for biasing the free end of lever 97 in a counterclockwise direction and stop means (not shown) is provided for positioning lever 97 so that the periphery of disc 95 will engage the arcuate surface 91c of cam 91 and be rotated thereby, due to frictional engagement, as the cam 91 rotates with drive shaft 21.
  • Nip rollers 100, 101 are preferably made of hard rubber and are mounted on rotatable shafts 102 and 103, respectively. The shafts are arranged such as to establish a contiguous relationship between the peripheries of the rollers.
  • a pulley 104 which is driven by belt 93.
  • a friction wheel 105 preferably comprised of a soft foam rubberlike material, is mounted on a rotatable shaft 106 which is vertically movable above the forward portion of copy sheet stack 56.
  • Spring means (not shown) is provided for biasing shaft 106 in a downward direction so as to insure frictional engagement between the wheel 105 and the uppermost copy sheet of the stack.
  • Drive means (not shown) is provided for producing a constant clockwise rotation of the friction wheel, as viewed in FIG. 1.
  • Such drive means is preferably activated by drive source 20.
  • An arcuate guide member 107 guides the leading edge 55a of sheet 55 into the nip of rollers and 101.
  • the copy sheet leading edge is within the nip of rollers 100 and 101 when cam 91 engages disc 95, the copy sheet will be advanced as the nip rollers are caused to rotate by belt 93. Such advancement by the nip rollers will continue during the period cam surface 91c is in contact with disc 95. This period is sufficient to advance the forward portion of copy sheet 55 into transfer station 40, under corona filaments 41 which cause the forward portion to electrostatically adhere to or contact the photoconductive surface 14. In this manner the copy sheet is drawn through rollers 100 and 101 even after cam surface 910 loses contact with disc 95.
  • the length of cam surface 910 could be such as to cause rollers 100 and 101 to advance the entire length of copy sheet 55 into transfer station 40.
  • a pair of curved guide members 108 and 109 serve to guide copy sheet 55 from rollers 100 and 101 to the transfer station.
  • Cam 91 is so oriented on drive shaft 21 that contact between cam surface 91c and disc 95 is made before the leading edge of element 10 reaches transfer station 40. ln this manner, the leading edge 55a of copy sheet 55 is caused to arrive at transfer station 40 slightly prior to the arrival of the leading edge of photosensitive element 10. Thus, the leading portion of the copy sheet overlaps the leading edge of element 10, thereby creating a flap 55b. It is this flap which facilitates the separation of the copy sheet from element 10.
  • a spring 79 is provided for biasing shaft 76 for counterclockwise rotation, as viewed in FIG. 1, and a stop means (not shown) is provided so as to cause shaft 76 to have a rest position such that finger 77 and lever 78 extend in the manner shown in phantom in FIG. 1.
  • lever 78 projects slightly within the circular path of element 10, adjacent the outer edge of rim 61, and finger 77 is radially exposed just outside the circular path, midway between rims 60 and 61.
  • the outer edge of rim 61 is provided with a laterally extending pin 62 which is arranged in a manner as to momentarily engage actuating lever 78 as rim 61 rotates.
  • pin 62 acts as a cam which imparts a clockwise rotational movement to shaft 76 during the period in which it is engaged with lever 78. Such clockwise rotation of shaft 76 will cause pickoff finger 77 to dip into the circular path of element 10.
  • Pin 62 is positioned on rim 61 in such a manner that the dipping of pickoff finger 77 occurs just prior to the passage of the leading edge 55a of copy sheet 55 thereunder.
  • the duration of the dipping movement of pickoff finger 77 is, of course, determined by the duration of the engagement between actuating lever 78 and pin 62, and the latter period is governed by the length of actuating lever 78.
  • a continued rotation of element causes pin 62 and lever 78 to disengage, thereby permitting finger 77 to return to its rest position under its spring bias.
  • finger 77 returns to its rest position it peels copy sheet 55 away from element 10 and directs it to fusing station 45 which comprises, for instance, an infrared heater which serves to melt the toner particles 38 and thereby fuse them to the copy sheet.
  • fusing station 45 comprises, for instance, an infrared heater which serves to melt the toner particles 38 and thereby fuse them to the copy sheet.
  • Element 10 is then recycled through the copying process while the copy sheet passes through fuser 45 to fix the image thereto.
  • FIGS. 36 a variety of arrangements is shown for accepting the leading portion of copy sheet 55, as presented by pickoff mechanism 75, and guiding the copy sheet further into fusing station 45 without disturbing the unfused toner image carried on the copy sheets surface.
  • a perforated roller 120 having a vacuum slit 121 contained therein is arranged as shown. The suction of the vacuum is directed so as to draw the copy sheet to roller 120 as it leaves the transfer station.
  • a grounded metal roller 130 could be used in place of the perforated roller 120 and a corona emission source 131 could be positioned as shown in FIG. 4 to cause the copy sheet 55 to be attracted to roller 130.
  • a soft brush 135 e.g., mohair
  • an air emission source 136 are respectively used to guide sheet 55 into the fusing station 45.
  • Electrographic apparatus having improved construction for facilitating the pick off of copy sheets, said apparatus comprising:
  • a copy sheet pickoff member mounted at a pickoff location along the image forming path of said apparatus and being movable between a first position below said imaging surface and a second position above said imaging sur face;
  • the invention defined in claim 1 further including separating means, located proximate said pickoff member in said second position, for urging away from said pickoff member the leading portion of a copy sheet separated from said imaging surface.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)
  • Discharging, Photosensitive Material Shape In Electrophotography (AREA)
  • Sheets, Magazines, And Separation Thereof (AREA)
US861508A 1969-09-26 1969-09-26 Pick off means for an electrostatic reproduction device Expired - Lifetime US3649115A (en)

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Application Number Priority Date Filing Date Title
US86150869A 1969-09-26 1969-09-26

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US3649115A true US3649115A (en) 1972-03-14

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US861508A Expired - Lifetime US3649115A (en) 1969-09-26 1969-09-26 Pick off means for an electrostatic reproduction device

Country Status (6)

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US (1) US3649115A (enrdf_load_stackoverflow)
JP (1) JPS498913B1 (enrdf_load_stackoverflow)
CA (1) CA947814A (enrdf_load_stackoverflow)
DE (1) DE2047701A1 (enrdf_load_stackoverflow)
FR (1) FR2063029B1 (enrdf_load_stackoverflow)
GB (1) GB1328672A (enrdf_load_stackoverflow)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3774907A (en) * 1971-09-16 1973-11-27 Xerox Corp Vacuum sheet stripping apparatus
US3809474A (en) * 1970-04-01 1974-05-07 N Mihalik Electrostatographic copying apparatus
US3827803A (en) * 1971-04-16 1974-08-06 Addressograph Multigraph Copier-duplicator machine
US3834808A (en) * 1970-12-29 1974-09-10 Canon Kk Electronic photographic copying machine
US3867026A (en) * 1970-08-03 1975-02-18 Minolta Camera Kk Electrophotographic copier of transfer type
US3893760A (en) * 1973-07-16 1975-07-08 Xerox Corp Transfer apparatus
US4013359A (en) * 1974-08-23 1977-03-22 Pitney-Bowes, Inc. Electrostatic copier including means for detaching paper from a photoconductor
US4013354A (en) * 1971-06-03 1977-03-22 Canon Kabushiki Kaisha Apparatus for separating transfer material in an electrostatic copying device
US4065121A (en) * 1975-11-10 1977-12-27 Ing. C. Olivetti & C., S.P.A. Sheet detaching device for electrophotographic copying machine
DE2855439A1 (de) 1977-12-21 1979-06-28 Ricoh Kk Blatt-trenneinrichtung fuer ein elektrophotographisches kopiergeraet
US4336992A (en) * 1980-05-19 1982-06-29 Xerox Corporation Apparatus for removing copy sheets from a roll fuser
US4387981A (en) * 1980-12-23 1983-06-14 Nashua Corporation Sheet stripping apparatus and method

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS49112315A (enrdf_load_stackoverflow) * 1973-03-03 1974-10-25
JPS5157421U (enrdf_load_stackoverflow) * 1974-10-31 1976-05-06
JPS5264723A (en) * 1975-11-25 1977-05-28 Shin Meiwa Ind Co Ltd Top cover structure of truk etc.

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2889758A (en) * 1954-12-24 1959-06-09 Ibm Electrophotographic printer
US3062108A (en) * 1955-02-07 1962-11-06 Xerox Corp Electrophotographic copying apparatus
US3109355A (en) * 1959-04-03 1963-11-05 Ritzerfeld Wilhelm Xerographic duplicator
US3504969A (en) * 1966-05-02 1970-04-07 Xerox Corp Imaging apparatus
US3506259A (en) * 1967-10-12 1970-04-14 Xerox Corp Electrostatic sheet detacking apparatus
US3508824A (en) * 1967-03-08 1970-04-28 Eastman Kodak Co Means for handling electrophotographic transfer sheets

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2889758A (en) * 1954-12-24 1959-06-09 Ibm Electrophotographic printer
US3062108A (en) * 1955-02-07 1962-11-06 Xerox Corp Electrophotographic copying apparatus
US3109355A (en) * 1959-04-03 1963-11-05 Ritzerfeld Wilhelm Xerographic duplicator
US3504969A (en) * 1966-05-02 1970-04-07 Xerox Corp Imaging apparatus
US3508824A (en) * 1967-03-08 1970-04-28 Eastman Kodak Co Means for handling electrophotographic transfer sheets
US3506259A (en) * 1967-10-12 1970-04-14 Xerox Corp Electrostatic sheet detacking apparatus

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3809474A (en) * 1970-04-01 1974-05-07 N Mihalik Electrostatographic copying apparatus
US3867026A (en) * 1970-08-03 1975-02-18 Minolta Camera Kk Electrophotographic copier of transfer type
US3834808A (en) * 1970-12-29 1974-09-10 Canon Kk Electronic photographic copying machine
US3827803A (en) * 1971-04-16 1974-08-06 Addressograph Multigraph Copier-duplicator machine
US4013354A (en) * 1971-06-03 1977-03-22 Canon Kabushiki Kaisha Apparatus for separating transfer material in an electrostatic copying device
US3774907A (en) * 1971-09-16 1973-11-27 Xerox Corp Vacuum sheet stripping apparatus
US3893760A (en) * 1973-07-16 1975-07-08 Xerox Corp Transfer apparatus
US4013359A (en) * 1974-08-23 1977-03-22 Pitney-Bowes, Inc. Electrostatic copier including means for detaching paper from a photoconductor
US4065121A (en) * 1975-11-10 1977-12-27 Ing. C. Olivetti & C., S.P.A. Sheet detaching device for electrophotographic copying machine
DE2855439A1 (de) 1977-12-21 1979-06-28 Ricoh Kk Blatt-trenneinrichtung fuer ein elektrophotographisches kopiergeraet
DE2857776C2 (enrdf_load_stackoverflow) * 1977-12-21 1988-05-05 Ricoh Co., Ltd., Tokio/Tokyo, Jp
US4336992A (en) * 1980-05-19 1982-06-29 Xerox Corporation Apparatus for removing copy sheets from a roll fuser
US4387981A (en) * 1980-12-23 1983-06-14 Nashua Corporation Sheet stripping apparatus and method

Also Published As

Publication number Publication date
GB1328672A (en) 1973-08-30
FR2063029A1 (enrdf_load_stackoverflow) 1971-07-02
JPS498913B1 (enrdf_load_stackoverflow) 1974-02-28
DE2047701A1 (de) 1971-04-15
FR2063029B1 (enrdf_load_stackoverflow) 1973-01-12
CA947814A (en) 1974-05-21

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