US3824011A - Transfer printing apparatus of electrophotographic apparatus - Google Patents

Transfer printing apparatus of electrophotographic apparatus Download PDF

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Publication number
US3824011A
US3824011A US00273425A US27342572A US3824011A US 3824011 A US3824011 A US 3824011A US 00273425 A US00273425 A US 00273425A US 27342572 A US27342572 A US 27342572A US 3824011 A US3824011 A US 3824011A
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US
United States
Prior art keywords
receptor sheet
transfer printing
photosensitive element
latent image
transfer
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
Application number
US00273425A
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English (en)
Inventor
M Watanabe
R Suzuki
S Miyakawa
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.)
Katsuragawa Electric Co Ltd
Original Assignee
Katsuragawa Electric Co Ltd
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
Priority claimed from JP5707871A external-priority patent/JPS5646156B1/ja
Priority claimed from JP5707971A external-priority patent/JPS5241661B1/ja
Application filed by Katsuragawa Electric Co Ltd filed Critical Katsuragawa Electric Co Ltd
Priority to US00433713A priority Critical patent/US3844652A/en
Application granted granted Critical
Publication of US3824011A publication Critical patent/US3824011A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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

  • McCoy [5 7] ABSTRACT In transfer printing apparatus of electrophotographic apparatus of the type wherein a receptor sheet is urged against a photosensitive element carried by a rotary drum by means of a transfer printing roller so as to transfer print an electrostatic latent image formed on the photosensitive element onto the receptor sheet there is provided a stationary separating member between the receptor sheet and the photosensitive element.
  • the separating member comprises a pair of strips which are disposed at an angle with respect to the direction of movement of the receptor sheet.
  • This invention relates to apparatus for separating a receptor sheet or a transfer printing paper from a photosensitive drum of an electrophotographic apparatus after an electrostatic latent image formed on the surface of the drum has been transfer printed onto the receptor sheet.
  • an electrostatic latent image formed on the surface of a rotary photosensitive element corresponding to an original is transfer printed onto a receptor sheet by means of a transfer printing roller which acts to urge the receptor sheet against the photosensitive element and then the transfer printed latent image is developed to obtain a visible image.
  • a transfer printing roller which acts to urge the receptor sheet against the photosensitive element and then the transfer printed latent image is developed to obtain a visible image.
  • a device wherein a peel off member is contacted against the periphery of the rotary photosensitive element for mechanically separating the receptor sheet (2) a device wherein the leading edge of the receptor sheet is slightly curved away from the periphery of the photosensitive element and a peel off member is disposed with its inner end slightly spaced apart from the periphery of the rotary photosensitive element so as not to damage it, (3) a device wherein after the transfer printing an air jet is applied to the leading edge of the receptor sheet to separate it from the photosensitive element, (4) a device wherein a suction drum is arranged behind the receptor sheet to separate it by suction (5) and combinations of these devices.
  • devices (1) and (2) it is impossible to transfer print the latent image along the entire length of the receptor sheet thus decreasing the effective area thereof.
  • Devices (3) and (4) not only require the provision of a source of pressurized air but also are difficult to positively peel off the receptor sheet where the quantity of the charge of the latent image is large as in the case of a perfectly black picture.
  • Another object of this invention is to provide novel separating apparatus of simple construction which can efficiently separate a receptor sheet from a rotary photosensitive element after the electrostatic latent image has been transfer printed but does not interfere with the transfer printing.
  • FIG. 1 shows a side view, partly broken away, of a photosensitive drum provided with separating apparatus embodying the invention
  • FIG. 2 is a plan view of a transfer printing roller and separating members
  • FIG. 3 shows a side view similar to FIG. 1 but showing a modified embodiment using two transfer printing rollers
  • FIG. 4 is a plan view showing the transfer printing roller and separating members of the embodiment shown in FIG. 3;
  • FIG. 5 is a plan view similar to FIG. 4 showing modified transfer printing rollers and
  • FIG. 6 is a plan view showing a modified separating member and modified transfer printing rollers.
  • a rotary photosensitive drum l0 utilized for forming an electrostatic latent image on the periphery thereof may be any suitable construction and the latent image may be formed by any suitable method.
  • the drum 10 carries a cylindrical photosensitive element 11 including an electrode layer 14, a photoconductive layer 13 and a transparent highly insulative layer 12 which are bonded together into an integral cylindrical structure.
  • the electrode layer 14 may be omitted.
  • the photoconductive layer 13 may be made of any photoconductive material or phosphor manifesting persistent internal polarization, such as CdS, Zn CdS, CdS or Zn CdS activated with copper or silver, selemium, anthraceneor TeSe.
  • a latent image may be formed on the surface of the highly insulative layer 12 by applying a first electric field across the photosensitive element to deposit a charge of one polarity on the surface of the highly insulative layer thereby establishing substantially uniform persistent internal polarization in the photoconductive layer, applying a second electric field across the photosensitive element to deposit a charge of the opposite polarity on the surface of the highly insulative layer, and projecting a light image upon the photoconductive layer through the highly insulative layer concurrently with the application of the second electric field thereby forming the latent image on the surface of the highly insulative layer.
  • Above described method is advantageous in that the latent image is not erased by later irradiation of light so that it is possible to carry out the transfer printing and developing operations in the bright.
  • the photoconductive layer contains a large number of deep charge trap levels, as in the case of Zn CdS activated with silver or copper, it is desirable to irradiate the latent image with uniform light from an electric lamp for example.
  • the latent image is formed by applying an electric field across the photosensitive element in the dark and then projecting a light image.
  • the latent image is readily erased by light it is necessary to carry out the transfer printing and developing operations in the dark as is well known in the art.
  • a transfer printing roller 15 which is made of rubber, for example, and is urged against the periphery of the rotary photosensitive element 11 by suitable means, not shown.
  • one, two or more spaced apart seperating members 16 of a fiber, string or tape of a synthetic resin such as nylon and polytetrafluoroethylene or metal foil are provided between stationary members 17, to extend through the nip between photosensitive element 11 and transfer printing roller 15 and the receptor sheet P is fed between the separating members and the transfer printing roller.
  • strips of polytetrafiuoroethylene are found to be most suitable because they have flat and smooth surface so that they do not damage the photosensitive element and receptor sheet by the contact friction, and because they have small elongation, a large shear strength and a long life. Even when a conductive material such as a metal foil or sheet is used, the electrostatic latent image would not be erased so long as the contact pressure between the separating members and the. photosensitive element is low. Conductive material has a large durability. As shown in FIG. 2, the separating members are disposed at an angle with respect to the direction of movement of the receptor sheet P which is indicated by arrow A.
  • the separating members are disposed between the rotary drum andthe receptor sheet they act to separate the receptor sheet from the rotary drum after transfer printing. As the rotary drum is rotated, the separating members arecontacted by the surface of the photosensitive element so that one may consider that the latent image would be erased or certain portion of the latent image would not be transfer printed. Actually, however, it was found that the latent image can be satisfactorily transfer printed where a relation a/W sin 0 is satisfied, where W represents the contact width between the peripheries of the photosensitive element and transfer printing roller and a the width of a separating member. Moreover, since the separating members are disposed at an angle with respect to the direction of movement of the receptor sheet P it is possible to prevent the receptor sheet from crimpling.
  • the material from which the separating members are formed should be wear resistant and should not damage the surfaces of the photosensitive element and the receptor sheet.
  • the result of experiment shows that a nylon fiber having a diameter of 0.2 mm and a tape of polytetrafluoroethylene having a thickness of 0.05 mm and a width of 3 mm are satisfactory.
  • the separation of the receptor sheet can be enhanced where the receptor sheet P is fed into the nip and removed from the nip, both at an angle with respect to the separating members, as diagrammatically shown in FIG. 1. Further, the separating members may be inclined in the same direction, but better results are obtained when they are inclined in the opposite directions as shown in FIG. 2.
  • two parallel transfer printing rollers a and 15b which are spaced apart in the direction of movement A of the receptor sheet are provided to increase the effective area of the contact width W.
  • portions of the latent image corresponding to widths 0 may not be effectively transfer printed by the interference of the separating members 16. However, these portions are. not interferred by the separating members 16 while the latent image is transfer printed by the other transfer printing roller 15a.
  • the transfer printing rollers 15a and 15b are provided with reduced diameter portions 18 which receiveseparating members 16 so as not urge them against the periphery of the photosensitive element.
  • the separating member 19 takesthe form of a web of a synthetic resin.
  • transfer printing roller 15b is formed with a reduced diameter portion 18 at the middle section thereof, whereas the other transfer printing roller 15a is provided with reduced diamter portions 18 on the opposite end sections.
  • the separating member 19 is provided with windows 20b and 20a at the larger diameter protions of the transfer printing rollers 15b and 15a, respectively. Windows 20a and 20b are staggered in the lateral direction with respect to the direction of movement of the receptor sheet.
  • the entire width of the receptor sheet interposed between the transfer printing rollers and the separating member is urged against the periphery of the photosensitive element to effect efficient transfer printing of the latent image.
  • the latent image can be formed by any method and by utilizing any one of many known photosensitive elements. If desired, suitable voltage may be applied between the rotary drum and the transfer roller to enhance transfer printing.
  • apparatus for transfer printing of electrophotographic images comprising a rotary drum provided with a photosensitive element on which an electrostatic image is to be formed, a receptor sheet and a transfer printing roller for urging said receptor sheet against the surface of said photosensitive element to transfer print said latent image onto said receptor sheet, the improvement which comprises a stationary separating member made of a sheet material having a width at least equal to the width of said receptor sheet interposed between said receptor sheet and said photosensitive element, said transfer printing roller being formed with a large diameter section and said separating member being provided with a window to receive said large diameter section.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)
US00273425A 1971-07-28 1972-07-20 Transfer printing apparatus of electrophotographic apparatus Expired - Lifetime US3824011A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US00433713A US3844652A (en) 1971-07-28 1974-01-16 Transfer printing apparatus of electrophotographic apparatus

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP5707871A JPS5646156B1 (ru) 1971-07-28 1971-07-28
JP5707971A JPS5241661B1 (ru) 1971-07-28 1971-07-28

Publications (1)

Publication Number Publication Date
US3824011A true US3824011A (en) 1974-07-16

Family

ID=26398083

Family Applications (1)

Application Number Title Priority Date Filing Date
US00273425A Expired - Lifetime US3824011A (en) 1971-07-28 1972-07-20 Transfer printing apparatus of electrophotographic apparatus

Country Status (6)

Country Link
US (1) US3824011A (ru)
CA (1) CA980172A (ru)
DE (1) DE2236400C3 (ru)
FR (1) FR2147671A5 (ru)
GB (1) GB1375762A (ru)
IT (1) IT963458B (ru)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3947019A (en) * 1973-07-27 1976-03-30 Minolta Camera Kabushiki Kaisha Copy paper sheet separating device
US4026541A (en) * 1974-10-25 1977-05-31 Xerox Corporation Sheet stripping device
US4033694A (en) * 1975-11-17 1977-07-05 Xerox Corporation Copier document ejector
US4110031A (en) * 1975-09-30 1978-08-29 Ricoh Company, Ltd. Electrostatic copying apparatus
US4624554A (en) * 1984-10-22 1986-11-25 Fuji Photo Film Co., Ltd. Charging and exposing head for use in electrophotographic apparatus
US5806284A (en) * 1997-03-03 1998-09-15 Apothecus Pharmaceutical Corp. Method and system for producing sealed packages of a film which is dissolved in a body fluid
US6137982A (en) * 1999-08-18 2000-10-24 Olympus America, Inc. Fuser stripper apparatus
US20050042002A1 (en) * 2003-08-22 2005-02-24 Hung Ming Te Roller mechanism for separating paper

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1900878A (en) * 1927-12-03 1933-03-07 Eastman Kodak Co Document photographing apparatus
US3101034A (en) * 1959-09-23 1963-08-20 Lumoprint Zindler Kg Apparatus for printing an original on to a copying paper
US3386730A (en) * 1966-10-14 1968-06-04 Speed O Print Business Machine Sheet separating device for photocopying machines
US3684363A (en) * 1969-08-30 1972-08-15 Canon Kk Device for separating recording medium for use in electrophotographic copying machines

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1900878A (en) * 1927-12-03 1933-03-07 Eastman Kodak Co Document photographing apparatus
US3101034A (en) * 1959-09-23 1963-08-20 Lumoprint Zindler Kg Apparatus for printing an original on to a copying paper
US3386730A (en) * 1966-10-14 1968-06-04 Speed O Print Business Machine Sheet separating device for photocopying machines
US3684363A (en) * 1969-08-30 1972-08-15 Canon Kk Device for separating recording medium for use in electrophotographic copying machines

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3947019A (en) * 1973-07-27 1976-03-30 Minolta Camera Kabushiki Kaisha Copy paper sheet separating device
US4026541A (en) * 1974-10-25 1977-05-31 Xerox Corporation Sheet stripping device
US4110031A (en) * 1975-09-30 1978-08-29 Ricoh Company, Ltd. Electrostatic copying apparatus
US4033694A (en) * 1975-11-17 1977-07-05 Xerox Corporation Copier document ejector
US4624554A (en) * 1984-10-22 1986-11-25 Fuji Photo Film Co., Ltd. Charging and exposing head for use in electrophotographic apparatus
US5806284A (en) * 1997-03-03 1998-09-15 Apothecus Pharmaceutical Corp. Method and system for producing sealed packages of a film which is dissolved in a body fluid
US6137982A (en) * 1999-08-18 2000-10-24 Olympus America, Inc. Fuser stripper apparatus
US20050042002A1 (en) * 2003-08-22 2005-02-24 Hung Ming Te Roller mechanism for separating paper
US7092666B2 (en) * 2003-08-22 2006-08-15 Lite-On Technology Corporation Roller mechanism for separating paper

Also Published As

Publication number Publication date
DE2236400B2 (de) 1977-12-08
CA980172A (en) 1975-12-23
GB1375762A (ru) 1974-11-27
IT963458B (it) 1974-01-10
FR2147671A5 (ru) 1973-03-09
DE2236400C3 (de) 1978-08-10
DE2236400A1 (de) 1973-02-08

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