US3691993A - Apparatus for transferring developed image - Google Patents

Apparatus for transferring developed image Download PDF

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Publication number
US3691993A
US3691993A US92038A US3691993DA US3691993A US 3691993 A US3691993 A US 3691993A US 92038 A US92038 A US 92038A US 3691993D A US3691993D A US 3691993DA US 3691993 A US3691993 A US 3691993A
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United States
Prior art keywords
image forming
forming surface
image
fibers
brush
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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US92038A
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English (en)
Inventor
Konrad A Krause
Yaqub Moradzadeh
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International Business Machines Corp
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International Business Machines Corp
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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
    • G03G15/14—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base
    • G03G15/16—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer
    • G03G15/163—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer using the force produced by an electrostatic transfer field formed between the second base and the electrographic recording member, e.g. transfer through an air gap
    • G03G15/1635—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer using the force produced by an electrostatic transfer field formed between the second base and the electrographic recording member, e.g. transfer through an air gap the field being produced by laying down an electrostatic charge behind the base or the recording member, e.g. by a corona device

Definitions

  • ABSTRACT An apparatus for transferring a developed electrostatic image from an image-bearing member to a medium such as copy paper in response to the evenly distributed field produced by a DC. biased metallized fiber brush roller which contacts the copy paper to produce the transfer.
  • One prior art method and apparatus for transferring a developed image to a copy sheet comprises a system wherein a corona discharge device is utilized to produce a charge on the back of the copy sheet to attract the image toner from the image forming surface to the sheet.
  • a corona discharge device is utilized to produce a charge on the back of the copy sheet to attract the image toner from the image forming surface to the sheet.
  • any vibration of the corona wire or dirt accumulation on the corona wire causes an uneven distribution of ionization and consequently causes uneven toner transfer which is observable on the copy.
  • the efficiency of the corona discharge device and hence the quality of the resultant image varies widely with changes in-temperature and relative humidity.
  • toner transfer by corona transfer techniques is rather inefficient.
  • Another prior art method and apparatus for transferring a developed image utilizes a conductive roller member and a bias potential applied to the roller to produce the transfer of the developed image to the copy sheet.
  • This method and apparatus provides satisfactory results under certain circumstances; however, the efficiency of transfer is low under certain conditions.
  • sparking and other image distorting phenomena may occur as the copy sheet is separated from the image forming surface. It is therefore an object of this invention to produce apparatus and method for transfering a developed image comprising electrostatic charged developer particles from an image forming surface to a web of transfer material to produce a high transfer efficiency and also a consistent image under widely varying environmental conditions.
  • The'apparatus comprises an image forming surface which may be an insulator or a photoconductive surface.
  • An electrostatic image is produced on the surface by known techniques and the image is developed utilizing electrostatically charged developer particles which are commonly known as toner.
  • a web of transfer material is provided adjacent to the image surface.
  • a brush having conductive fibers is also mounted adjacent to the image surface and a constant potential difference is produced between the image surface and the brush member by means of a suitable power supply. Relative motion is procedure between the brush and the image surface so that the tips of the brush fibers move the web of transfer material into intimate contact with the image surface.
  • the potential difference is operative to attract the toner particles comprising the developed image to the web of transfer material and due to the constant force provided by the brush fibers, substantially all of the developer particles are transferred from the image surface to the web of transfer material.
  • the image is then fixed to the web of transfer material by any suitable technique.
  • FIG. 1 is a schematic view of an electrophotographic apparatus embodying the present invention
  • FIG. 2 is an enlarged view showing in greater detail the metallized fiber embodiment of the transfer brush means for the apparatus shown in FIG. 1.
  • FIG. 3 is a partial cross section view along the lines 3-3 ofFIG. lj
  • FIG. 4 is a schematic view of an alternate embodiment of the apparatus embodying the invention wherein a flat transfer brush means is utilized.
  • FIG. 1 One example of a particular apparatus in which the subject invention is adapted for use is the electrophotographic apparatus shown in FIG. 1.
  • a rotatable drum 10 carries around its periphery an electrophotographic photoconductive member 12 on which is directed an image which it is desired to be reproduced on the paper sheet 14.
  • the surface of the photoconductor is uniformly charged to a predetermined polarity by corona discharge device 16.
  • a document having the image to be copied is placed so that a suitable exposure means is operable to direct the image to expose station 18 onto the surface of the photoconductor 12.
  • Relative motion is provided for the document at a speed synchronized with the surface speed of drum 10 in a manner known in the art.
  • the photoconductive surface is illuminated by the image, the surface is discharged leaving a charged pattern in a form of the image to be copied.
  • the drum passes a development station 20 at which a toner-carrier mixture 22 is cascaded across or otherwise brought in contact with the electrostatic image on the surface of the photoconductor 12 as is known in the art.
  • the toner having a charge opposite from the polarity of the electrostatic image charge is attracted to the drum surface to render the image visible.
  • a copy paper 14 is fed into contact with the developed electrostatic image by the rollers 24.
  • a soft brush means 26 having resilient conductive fibers is disposed beneath the paper at the area of contact with the drum.
  • Power supply 28 is coupled to produce a unidirectional potential between brush member 26 and the conductive backing of photoconductor 12. The potential has a polarity opposite that of the toner, thereby attracting the toner to the copy paper.
  • the paper 14 is separated from the drum and fed past a fusing station (not shown) which serves to fuse and permanently fix the toner to the paper. Since transfer of all the image toner 29 is not usually accomplished, residual toner 30 usually remains on the drum surface after a transfer operation.
  • the drum continues to rotate past a cleaning apparatus 32 which cleans the surface of the photoconductor and removes any excess toner. This operation completes the cycling of the drum for reproducing the desired image.
  • the brush member 26 comprises a plurality of unitary fibers 25 which are permanently attached to the base member 27.
  • the fibers extend substantially outward from the base and the fibers are of substantially uniform length so that a potential applied to the brush .be produced without regard to the density of the developer particles in different portions of the developed image.
  • the fibers are preferably of a thickness approximating the size of .the individual toner particles so that the image transfer can be accom- .plished without distortion of the image. This size fiber also eliminates damage to the'image forming surface and to the copy sheet which would result from the use of thicker and stiffer brush fibers.
  • One suitable material is stainless steel fibers approximately 12 microns in diameter which are woven into a plush fabric which is then attached to a suitable support member. This type of brush produces excellent transfer, but is difficult to manufacture with all fibers upstanding so that a uniform field and a uniform force are produced by the brush.
  • brush means 26' comprises a base member 38 to which is fixed a plurality of uniform upstanding fibers.
  • the fibers comprise an inner nonconductive part 40 which has an outer conductive coating 42. This construction gives control over the conductivity of the fibers so that an effective technique for the prevention of arching during separation of the image surface and the transfer material is produced.
  • One suitable technique for coating the surface of the fibers is the technique known in the art as electroless plating.
  • One exampleof a brush construction utilizing this technique comprises a rayon plush fabric since this material contains a combination of physical, chemical and electrostatic properties which are suitable for this use;
  • Other types of knit or construction such as sliver knit or flocking may be used for this purpose which results in plush fabrics with upstanding or substantially upstanding fibers.
  • the particular fabric utilizes a double shuttle type of weave which is essential in keeping the fibers separated. The fibers are first washed and then sensitized by immersion in a suitable sensitizing solution such as stannous chloride.
  • the fabric is then activated utilizing a suitable activating solution, for example, immersion in acidic palladium chloride solutions.
  • a suitable activating solution for example, immersion in acidic palladium chloride solutions.
  • the material is placed in a proper plating bath such as a copper plating bath for a time which varies with the type of bath and the desired conductivity to be produced in the fibers.
  • the material is then rinsed and dried. This operation produces a suitable conductive coating on the fibers so that a brush is produced by fixing the fabric to a suitable support member to produce the transfer brush.
  • Other types of conductivecoating may be produced on the fiber surface using electroless plating, for example, nickel, cobalt, iron, etc.
  • a trace of phosphorus usually .cod'ep'osits with the metallic layer.
  • Precious metals such as gold, platinum and rhodium can be deposited by a double plating technique in which copper is first deposited on the synthetic fiber by the electroless plating method followed by an immersion plating technique in which all or part of copper film is converted to the desired precious metallic film.
  • an acidic salt solution of .precious metal is employed in which the copper plated fabric is immersed, then rinsed and dried.
  • Relative motion may be produced between the image forming surface and the brush means 26 by any suitable means.
  • drum 10 is rotated about its axis from a suitable drive motor 34 by suitable belts or gears (shown dotted in the drawings).
  • brush means 26 may also be rotated.
  • Brush 26 may be rotated at a speed synchronized with the drum speed or driven at a faster rate to lessen the adverse effect in the event of any separation or bunching of the fibers in brush 26.
  • the flat brush 26" shown in FIG. 4 is maintained stationary and reliable transfer of the image is produced.
  • Brush 26 should maintain at least a minimum area of contact to provide good transfer.
  • a particular apparatus utilized a flat image forming surface and a 2% inch diameter transfer brush. The brush was mohair with electroless plated copper fibers about one-eighth of an inch long. A range of potentials (700-1 ,200) and brush compressions were tried and the optimum configuration for this apparatus was found to be a potential of 1,100 volts with about 2mm compression in the brush fibers which produced a contact area approxi-v mately 1 inch wide. A 2% inch diameter stainless steel fiber brush with /4; inch fibers was also utilized. The optimum transfer current which produced good transfer without arcing was found to be 0.2[LA/ill A series resistor was used with the stainless steel fiber brush to limit the current to this level.
  • the invention is also applicable to other types of image producing systems other than the embodiment shown in the drawings.
  • a higher transfer potential was found to be more suitable.
  • Potentials in the range of 1,000 to 2,000 volts were found suitable for good transfer in apparatus of this type.
  • Apparatus for transferring a developed image comprising electrostatically charged developer particles from an image forming surface to a web of transfer material comprising:
  • said brush means comprises a cylindrical base member mounted for rotation about an axis and wherein said fibers are affixed to said base member and extend substantially outward from said axis.
  • Apparatus for transferring a developed image comprising electrostatically charged developer particles from an image forming surface to a web of transfer material comprising:
  • brush means having a plurality of resilient fibers, said fibers comprising non-conductive fibers having a conductive coating thereon;
  • said non-conductive fiber comprises synthetic material.

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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)
  • Brushes (AREA)
US92038A 1970-11-23 1970-11-23 Apparatus for transferring developed image Expired - Lifetime US3691993A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US9203870A 1970-11-23 1970-11-23

Publications (1)

Publication Number Publication Date
US3691993A true US3691993A (en) 1972-09-19

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Family Applications (1)

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US92038A Expired - Lifetime US3691993A (en) 1970-11-23 1970-11-23 Apparatus for transferring developed image

Country Status (6)

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US (1) US3691993A (de)
JP (1) JPS5010738B1 (de)
CA (1) CA948028A (de)
DE (1) DE2156299C3 (de)
FR (1) FR2115791A5 (de)
GB (1) GB1348910A (de)

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3765757A (en) * 1971-12-29 1973-10-16 Xerox Corp Transport arrangement for thin sheet material
US3847119A (en) * 1972-03-27 1974-11-12 Xerox Corp Transfer roller assembly
US3854974A (en) * 1970-08-28 1974-12-17 Xerox Corp Method for transferring a toner image
US3866573A (en) * 1971-10-21 1975-02-18 Agfa Gevaert Ag Electrostatic copying apparatus
US3877416A (en) * 1973-04-23 1975-04-15 Xerox Corp Humidity corrected transfer apparatus
US3877417A (en) * 1973-10-15 1975-04-15 Xerox Corp Transfer corona generating device with support brushes
US3884185A (en) * 1973-09-06 1975-05-20 Xerox Corp Coated wire developer brush
US3900591A (en) * 1973-06-08 1975-08-19 Minnesota Mining & Mfg Developed image transfer
US3993021A (en) * 1973-06-08 1976-11-23 Minnesota Mining And Manufacturing Company Transfer device
DE3117210A1 (de) * 1980-04-30 1982-02-18 Tokyo Shibaura Denki K.K., Kawasaki, Kanagawa Uebertragungseinrichtung
US4330349A (en) * 1980-10-02 1982-05-18 Xerox Corporation Method for preparing conductive fiber brushes
US4336565A (en) * 1980-08-04 1982-06-22 Xerox Corporation Charge process with a carbon fiber brush electrode
US4341456A (en) * 1980-06-27 1982-07-27 Xerox Corporation Transfer system for a xerographic reproduction machine
US4363550A (en) * 1979-12-06 1982-12-14 Tokyo Shibaura Denki Kabushiki Kaisha Recording sheet separating device in a transfer-type electronic copying machine
US4380384A (en) * 1980-01-25 1983-04-19 Tokyo Shibaura Denki Kabushiki Kaisha Charging device for electronic copier
US4408862A (en) * 1980-01-18 1983-10-11 Tokyo Shibaura Denki Kabushiki Kaisha Developing apparatus for electrostatic copying machine
US4455078A (en) * 1980-10-14 1984-06-19 Tokyo Shibaura Denki Kabushiki Kaisha Charging device having a conductive particle impregnated strand lined contact member
US4553191A (en) * 1982-12-03 1985-11-12 Xerox Corporation Static eliminator
US4761709A (en) * 1984-10-29 1988-08-02 Xerox Corporation Contact brush charging
US4998143A (en) * 1988-09-20 1991-03-05 Hitachi, Ltd. Electrophotographic image transfer member, electrophotographic image transfer device and electrophotographic recording apparatus
US5643706A (en) * 1995-11-30 1997-07-01 Xerox Corporation Process for preparing electroconductive members
US5729810A (en) * 1993-01-22 1998-03-17 Xerox Corporation Overcoated transfer roller for transferring developed images from one surface to another
US6548154B1 (en) 2000-11-28 2003-04-15 Xerox Corporation Electrical charge relaxable wear resistant coating for bias charging or transfer member
US20050265756A1 (en) * 2004-05-25 2005-12-01 Xerox Corporation Xerographic transfer station using a semiresistive brush
US20070003761A1 (en) * 2003-05-19 2007-01-04 Toray Industries, Inc. Fibers excellent in magnetic field responsiveness and conductivity and product consisting of it

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5215438U (de) * 1975-07-21 1977-02-03
JPS52104543U (de) * 1976-02-06 1977-08-09
JPS52107245U (de) * 1976-02-09 1977-08-15
JPS55117250U (de) * 1979-02-14 1980-08-19
DK153337C (da) * 1979-04-11 1988-11-14 Platonec Aps Fremgangsmaade til toer sensibilisering af en isolerende overflade
US4382673A (en) * 1980-03-25 1983-05-10 Tokyo Shibaura Denki Kabushiki Kaisha Transfer device

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2901374A (en) * 1955-05-04 1959-08-25 Battelle Development Corp Development of electrostatic image and apparatus therefor
US2959153A (en) * 1955-12-21 1960-11-08 Ibm Xerographic image developing apparatus
US3152012A (en) * 1960-12-19 1964-10-06 Ibm Apparatus for the development of electrostatic images
US3328193A (en) * 1962-10-02 1967-06-27 Australia Res Lab Method of and means for the transfer of images
US3368894A (en) * 1963-11-05 1968-02-13 Australia Res Lab Multiple copy printing method and apparatus
US3551146A (en) * 1965-06-28 1970-12-29 Xerox Corp Induction imaging system
US3589895A (en) * 1967-07-17 1971-06-29 Eastman Kodak Co Electrographic developing method suited for transfer electrophotography without cleaning
US3599605A (en) * 1969-03-20 1971-08-17 Ibm Self-biasing development electrode for electrophotography
US3627523A (en) * 1968-03-14 1971-12-14 Addressograph Multigraph Multiple powder transfer in photoelectrostatic duplicator

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2901374A (en) * 1955-05-04 1959-08-25 Battelle Development Corp Development of electrostatic image and apparatus therefor
US2959153A (en) * 1955-12-21 1960-11-08 Ibm Xerographic image developing apparatus
US3152012A (en) * 1960-12-19 1964-10-06 Ibm Apparatus for the development of electrostatic images
US3328193A (en) * 1962-10-02 1967-06-27 Australia Res Lab Method of and means for the transfer of images
US3368894A (en) * 1963-11-05 1968-02-13 Australia Res Lab Multiple copy printing method and apparatus
US3551146A (en) * 1965-06-28 1970-12-29 Xerox Corp Induction imaging system
US3589895A (en) * 1967-07-17 1971-06-29 Eastman Kodak Co Electrographic developing method suited for transfer electrophotography without cleaning
US3627523A (en) * 1968-03-14 1971-12-14 Addressograph Multigraph Multiple powder transfer in photoelectrostatic duplicator
US3599605A (en) * 1969-03-20 1971-08-17 Ibm Self-biasing development electrode for electrophotography

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3854974A (en) * 1970-08-28 1974-12-17 Xerox Corp Method for transferring a toner image
US3866573A (en) * 1971-10-21 1975-02-18 Agfa Gevaert Ag Electrostatic copying apparatus
US3765757A (en) * 1971-12-29 1973-10-16 Xerox Corp Transport arrangement for thin sheet material
US3847119A (en) * 1972-03-27 1974-11-12 Xerox Corp Transfer roller assembly
US3877416A (en) * 1973-04-23 1975-04-15 Xerox Corp Humidity corrected transfer apparatus
US3900591A (en) * 1973-06-08 1975-08-19 Minnesota Mining & Mfg Developed image transfer
US3993021A (en) * 1973-06-08 1976-11-23 Minnesota Mining And Manufacturing Company Transfer device
US3884185A (en) * 1973-09-06 1975-05-20 Xerox Corp Coated wire developer brush
US3877417A (en) * 1973-10-15 1975-04-15 Xerox Corp Transfer corona generating device with support brushes
US4363550A (en) * 1979-12-06 1982-12-14 Tokyo Shibaura Denki Kabushiki Kaisha Recording sheet separating device in a transfer-type electronic copying machine
US4408862A (en) * 1980-01-18 1983-10-11 Tokyo Shibaura Denki Kabushiki Kaisha Developing apparatus for electrostatic copying machine
US4380384A (en) * 1980-01-25 1983-04-19 Tokyo Shibaura Denki Kabushiki Kaisha Charging device for electronic copier
DE3117210A1 (de) * 1980-04-30 1982-02-18 Tokyo Shibaura Denki K.K., Kawasaki, Kanagawa Uebertragungseinrichtung
US4341456A (en) * 1980-06-27 1982-07-27 Xerox Corporation Transfer system for a xerographic reproduction machine
US4336565A (en) * 1980-08-04 1982-06-22 Xerox Corporation Charge process with a carbon fiber brush electrode
US4330349A (en) * 1980-10-02 1982-05-18 Xerox Corporation Method for preparing conductive fiber brushes
US4455078A (en) * 1980-10-14 1984-06-19 Tokyo Shibaura Denki Kabushiki Kaisha Charging device having a conductive particle impregnated strand lined contact member
US4553191A (en) * 1982-12-03 1985-11-12 Xerox Corporation Static eliminator
US4761709A (en) * 1984-10-29 1988-08-02 Xerox Corporation Contact brush charging
US4998143A (en) * 1988-09-20 1991-03-05 Hitachi, Ltd. Electrophotographic image transfer member, electrophotographic image transfer device and electrophotographic recording apparatus
US5729810A (en) * 1993-01-22 1998-03-17 Xerox Corporation Overcoated transfer roller for transferring developed images from one surface to another
US5643706A (en) * 1995-11-30 1997-07-01 Xerox Corporation Process for preparing electroconductive members
US6548154B1 (en) 2000-11-28 2003-04-15 Xerox Corporation Electrical charge relaxable wear resistant coating for bias charging or transfer member
US20070003761A1 (en) * 2003-05-19 2007-01-04 Toray Industries, Inc. Fibers excellent in magnetic field responsiveness and conductivity and product consisting of it
US8017233B2 (en) * 2003-05-19 2011-09-13 Toray Industries, Inc. Fibers having excellent responsiveness to magnetic fields and excellent conductivity, as well as articles made of the same
US20050265756A1 (en) * 2004-05-25 2005-12-01 Xerox Corporation Xerographic transfer station using a semiresistive brush
US7158746B2 (en) 2004-05-25 2007-01-02 Xerox Corporation Xerographic printer having a semiresistive rotatable brush in the transfer zone

Also Published As

Publication number Publication date
DE2156299C3 (de) 1980-12-04
CA948028A (en) 1974-05-28
DE2156299A1 (de) 1972-05-31
DE2156299B2 (de) 1980-04-03
JPS5010738B1 (de) 1975-04-24
FR2115791A5 (de) 1972-07-07
GB1348910A (en) 1974-03-27

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