US3838918A - Transfer apparatus - Google Patents

Transfer apparatus Download PDF

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Publication number
US3838918A
US3838918A US00335968A US33596873A US3838918A US 3838918 A US3838918 A US 3838918A US 00335968 A US00335968 A US 00335968A US 33596873 A US33596873 A US 33596873A US 3838918 A US3838918 A US 3838918A
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United States
Prior art keywords
recited
transfer member
micro
amperes
rms
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Expired - Lifetime
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US00335968A
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English (en)
Inventor
D Fisher
C Dodd
D Jones
G Marshall
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
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Xerox Corp
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Filing date
Publication date
Application filed by Xerox Corp filed Critical Xerox Corp
Priority to US00335968A priority Critical patent/US3838918A/en
Priority to NL7401232A priority patent/NL7401232A/xx
Priority to CA191,682A priority patent/CA1030400A/fr
Priority to DE2405511A priority patent/DE2405511C3/de
Priority to JP49019837A priority patent/JPS6131460B2/ja
Priority to IT48552/74A priority patent/IT1008903B/it
Priority to BR1344/74A priority patent/BR7401344D0/pt
Priority to BE141264A priority patent/BE811434A/fr
Priority to GB873374A priority patent/GB1445243A/en
Priority to FR7406475A priority patent/FR2219452B1/fr
Priority to AU66033/74A priority patent/AU6603374A/en
Application granted granted Critical
Publication of US3838918A publication Critical patent/US3838918A/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
    • G03G15/14—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
    • G03G15/169—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 with means for preconditioning the toner image before the transfer

Definitions

  • PATENTED W Y 74 sum 10F 2 TRANSFER APPARATUS BACKGROUND OF THE INVENTION This invention relates generally to an electrostatographic printing machine, and more particularly concerns an improved transfer system for use therein.
  • An electrostatographic process involves the creation of an electrostatic latent charge pattern and the reproduction of the charge pattern in viewable form.
  • the field of electrostatography includes electrophotography and electrography.
  • Electrophotography is a class of electrostatography which employs a photosensitive medium to form, with the aid of electromagnetic radiation, an electrostatic latent charge pattern.
  • Electrography is the class of electrostatography which utilizes an insulating medium to form, without the aid of electromagnetic radiation, the electrostatic latent charge pattern.
  • Transfer which is the act of transferring toner particles deposited on the electrostatic latent charge pattern, in image configuration, to a sheet of support material, may be employed in either of the preceding classes of electrostatography.
  • an electrophotographic printing machine will be described as an illustrative embodiment of the foregoing processes wherein the transfer system of the present invention may be incorporated.
  • an image bearing member or photosensitive element having a photoconductive insulating layer is charged to a sub stantially uniform potential in order to sensitize its surface.
  • the charged photoconductive surface is exposed to a light image of an original document.
  • the charge is selectively dissipated in the irradiated areas in accordance with the light intensity projected onto the photoconductive surface creating an electrostatic latent image thereon.
  • developer mixes employed are well known, and generally comprise dyed or colored thermoplastic powders, known in the art as toner particles, which are mixed with coarser carrier granules such as ferromagnetic granules.
  • the developer mix is selected such that the toner particles acquire the appropriate charge relative to the electrostatic latent image recorded on the photoconductive surface.
  • the greater attractive force of the electrostatic latent image recorded thereon causes the toner particles to move from the carrier granules and adhere thereto.
  • the toner powder image developed on the photoconductive surface may be transferred to a sheet of support material such as paper or a thermoplastic sheet amongst others, to which it may be permanently affixed by any suitable means.
  • the toner powder image has been transferred to the sheet of support material by an electric field created by a corona generator similar to that disclosed in U.S. Pat. No. 2,836,725 issued to Vyverberg in 1958.
  • a corona generator of this type induces transfer to the sheet of support material by spraying a corona discharge having a polarity opposite to that carried by the toner particles on the photoconductive surface, thereby causing the toner particles to be electrostatically transferred to the sheet of support material.
  • This type of corona generator has proven to be ex tremely reliable for transferring a single toner powder image to a sheet of support material.
  • such a corona generator does not readily lend itself to transferring multiple toner powder images, in superimposed registration with one another. as is required in multicolor electrophotographic printing.
  • the biased transfer roll generates a high voltage discharge in the proximity of the surface of the paper or, it may be applied by means of a conductive cylinder in contact with the paper as disclosed in U.S. Pat. No. 2,807,233 issued to Fitch in 1957.
  • a sheet of support material is interposed between the conductive roller and a surface having the toner powder image thereon.
  • a charge of opposite polarity from the toner particles is deposited on the back side of the sheet of support material which attracts the toner powder image thereto.
  • a direct current supply is required to operate the transfer mechanism.
  • an apparatus for transferring charged particles from a support surface to a sheet of support material for transferring charged particles from a support surface to a sheet of support material.
  • corona generating means operatively associated with a transfer member.
  • Corona generating means positioned adjacent the support surface, is adapted to apply an alternating charge potential thereto.
  • the transfer member has a sheet of support material secured thereto and cooperates electrically with the support surface. This is achieved by electrically biasing the transfer member to a potential of sufficient magnitude to attract the preconditioned charged particles from the support surface to the sheet of support material.
  • FIG. 1 is a schematic perspective view of a multicolor electrophotographic printing machine incorporating the present invention therein;
  • FIG. 2 is a schematic perspective view of the transfer apparatus of the present invention, as utilized in the FIG. 1 printing machine;
  • FIG. 3 is a fragmentary perspective view of the corona generator used in the FIG. 2 transfer apparatus.
  • FIG. 1 schematically illustrates the various components of a printing machine for producing multi-color copies from a colored original.
  • the transfer apparatus of the present invention is particularly well adapted for use in an electrophotography printing machine, it should become evident from the following discussion that it is equally well suited for use in a wide variety of electrostatographic printing machines and is not necessarily limited in its application to the particular embodiment shown herein.
  • the printing machine illustrated in FIG. I employs an image bearing member having a drum 10 with a photoconductive surface 12 mounted on the exterior circumferential surface thereof.
  • Drum 10 is mounted rotatably within the machine frame.
  • One type of suitable photoconductive material is disclosed in U.S. Pat. No. 3,655,377 issued to Sechak in 1972.
  • a series of processing stations are located such that as drum l rotates in the direction of arrow 14 it passes sequentially therethrough.
  • Drum is driven at a predetermined speed by a drive motor (not shown) relative to the various machine operating mechanisms.
  • the machine logic coordinates the operations at each station with one another to produce the proper sequence of events thereat.
  • Drum 10 initially moves photoconductive surface 12 through charging station A.
  • Charging station A has positioned thereat a corona generating device indicated generally at 16.
  • Corona generating device 16 extends in a generally transverse direction across photoconductive surface 12. This readily enables corona generating device 16 to charge photoconductive surface 12 to a relatively high substantially uniform potential.
  • the foregoing corona generating device 16 is, preferably, of a type described in U.S. Pat. No. 2,778,946 issued to Mayo in 1957.
  • Exposure station B includes thereat a moving lens system, generally designated by the reference numeral l8, and a color filter mechanism shown generally at 20.
  • a suitable moving lens system is disclosed in U.S. Pat. No. 3,062,108 issued to Mayo in 1962, and a suitable color filter mechanism is described in copending application Ser. No. 830,282 filed in 1969.
  • an original document 22 such as a sheet of paper, book or the like is placed face down upon transparent viewing platen 24.
  • Lamp assembly 26, filter mechanism 20 and lens 18 move in a timed relation with drum [0 to scan successive incremental areas of original document 22 disposed upon platen 24.
  • Filter mechanism 20 is adapted to interpose selected color filters into the optical light path.
  • the appropriate color filter operates on the light rays passing through lens 18 to record an electrostatic latent image on photoconductive surface 12 corresponding to a preselected spectral region of the electromagnetic wave spectrum. hereinafter referred to as a single color electrostatic latent image.
  • drum 10 rotates the single color electrostatic latent image recorded on photoconductive surface 12 to development station C.
  • Development station C includes thereat three individual developer units, generally indicated by the reference numerals 28, 30 and 32, respectively.
  • a suitable development station employing a plurality of developer units is disclosed in copending application Ser. No. 255,259 filed in 1972.
  • the developer units are all of a type referred to generally as magnetic brush developer units.
  • a typical magnetic brush developer unit utilizes a magnetizable developer mix having carrier granules and toner particles therein. The developer mix is continually brought through a directional flux field to form a brush thereof.
  • the single color electrostatic latent image recorded on photoconductive surface 12 is developed by bringing the brush of developer mix into contact therewith.
  • Each of the respective developer units contain discretely colored toner particles corresponding to the complement of the spectral region of the wavelengths of light transmitted through filter 20, e.g., a green filtered electrostatic latent image is rendered visible by depositing green absorbing magenta toner particles thereon, blue and red latent images are developed with yellow and cyan toner particles, respectively.
  • Drum 10 is, next, rotated to transfer station D where the toner powder image adhering electrostatically to photoconductive surface 12 is transferred to a sheet of support material 34.
  • Support material 34 may be plain paper or a sheet of thermoplastic material, amongst others.
  • Transfer station D includes thereat corona generating means indicated generally at 36, and a transfer member, designated generally by reference numeral 38.
  • Corona generator 36 is excited with an alternating current and is arranged to spray ions on photoconductive surface 12 so as to precondition the toner powder image adhering electrostatically thereto. In this way, the preconditioned toner powder image will more readily be transferred from the electrostatic latent image recorded on photoconductive surface 12 to support material 34 by transfer member 38.
  • Transfer member 38 is a roll adapted to recirculate support material 34 and is electrically biased to a potential of sufficient magnitude and polarity to attract electrostatically the preconditioned toner particles from the latent image recorded on photoconductive surface 12 to support material 34.
  • Transfer roll 38 rotates in synchronism with photoconductive surface 12. Inasmuch as support material 34 is secured releasably thereon for movement in the recirculating path therewith, successive toner powder images may be transferred thereto in superimposed registration with one another. In this case, transfer roll 38 rotates in the direction of arrow 40 at substantially the same angular velocity as photoconductive drum l0. Corona generator 36 and transfer member 38 will be described hereinafter in greater detail with reference to FIGS. 2 and 3.
  • Support material 34 is advanced from a stack 42 thereof.
  • Feed roll 44 in operative communication with retard roll 46, advances and separates the uppermost sheet from stack 42 disposed on tray 48.
  • the advancing sheet moves into a chute 50 which directs it into the nip between register rolls 52.
  • gripper fingers mounted on transfer roll 38 secure releasably thereon support material 34 for movement in a recirculating path therewith.
  • gripper fingers 54 release support material 34 and space it from transfer roll 38.
  • Stripper bar 56 is then interposed therebetween to separate support material 34 from transfer roll 38.
  • endless belt conveyor 58 advances support material 34 to fixing sta tion E.
  • a fuser indicated generally at 60, coalesces the transferred powder image to support material 34.
  • suitable fuser is described in US. Pat. No. 3,498,592 issued to Moser et al in 1970.
  • support material 34 is advanced by endless belt conveyors 62 and 64 to catch tray 66 for subsequent removal therefrom by the machine operator.
  • the residual toner particles are removed from the photoconductive surface 12 as it moves through cleaning station F.
  • the residual toner particles are first brought under the influence of a cleaning corona generating device (not shown) adapted to neutralize the electrostatic charge remaining thereon.
  • the neutralized toner particles are then mechanically cleaned from photoconductive surface 12 by a rotatably mounted fibrous brush 68.
  • a suitable brush cleaning device is described in US. Pat. No. 3,590,412 issued to Gerbasi in 1971. Rotatably mounted on brush 68 is positioned at cleaning station F and maintained in contact with photoconductive surface 12. In this manner, residual toner particles remaining on photoconductive surface 12 after each transfer operation are readily removed therefrom.
  • FIG. 2 depicts the transfer apparatus associated with photoconductive surface 12 of drum 10.
  • Transfer roll 38 includes an aluminum tube 68, preferably. having about a one-fourth inch thick layer of urethane 70 cast thereabout.
  • a polyurethane coating 72 preferably of about 1 mil thick. is sprayed over the layer of cast urethane 70.
  • transfer roll 38 has a durometer hardness ranging from about 10 units to about 30 units on the Shore A scale.
  • the resistivity of transfer roll 38 preferably, ranges from about I0 to about l0 ohm-centimeters.
  • a direct current bias voltage is applied to aluminum tube 68 via suitable means such as a carbon brush and brass ring assembly (not shown).
  • Transfer roll 38 is substantially the same diameter as drum l0 and is driven at substantially the same speed thereat. Contact between photoconductive surface 12 of drum l0 and transfer roll 38 with support material 34 interposed therebetween, is preferably limited to a maximum of about 1.0 pound linear force.
  • transfer roll 38 includes a pair of tapered end bells which are secured to one another by three tie rods. Compression springs limit the tension of the tie rods to about 10 pounds.
  • a pair of spring loaded pivot arms located on a stationary shaft support transfer roll 38 in the electrophotographic printing machine. Solenoids and secondary springs (loaded to about 0.02 pounds per linear inch) lift transfer roll 38 with support material secured thereon against photoconductive surface 12 of drum 10.
  • Transfer roll 38 is moved approximately one-eighth of an inch in order to engage photoconductive surface 12.
  • a spring loaded yoke supports transfer roll 38. This yoke is articulated to permit transfer roll 38 to be adjustably positioned about its own center line and the center line of drum 10.
  • a synchronous speed main drive motor rotates transfer roll 38. This drive is coupled directly to transfer roll 38 by flexible metal bellows 74 which permits the lowering and raising of transfer roll 38. Synchronization of transfer roll 38 and drum 10 is accomplished by precision gears (not shown) coupling the main drive motor to both transfer roll 38 and drum 10.
  • Corona generator 36 includes an elongated shield 98 preferably made from a conductive material such as an aluminum extrusion.
  • Elongated shield 98 is substantially U-shaped and may be grounded or, in lieu thereof, biased to a suitable electrical voltage level.
  • a discharge electrode 100 is mounted in the chamber defined by U-shaped shield 98.
  • Discharge electrode 100 is, preferably, a coronode wire approximately 0.0035 inches in diameter and extends longitudinally along the length of shield 98.
  • Coronode wire 100 is made preferably from tungsten having a tungsten oxide coating thereon. Discharge electrode 100 is excited so as to produce a flow of ions therefrom.
  • the ion flow is adapted to precondition the toner particles deposited on the electrostatic latent image of photoconductive surface 12.
  • transfer roll 38 enhances the efficiency of attracting the toner powder image from the electrostatic latent image recorded on photoconductive surface 12.
  • discharge electrode I00 is excited at about 1 l0 micro-amperes and about 4,400 volts RMS, the range being from about micro-amperes at about 3,000 volts RMS to about 200 micro-amperes at about 5,000 volts RMS.
  • the alternating current output from coronode wire 100 to photoconductive surface 12 with the toner powder thereon ranges from about 3.0 to about 5.0 micro-amperes, and is preferably about 4.0 micro-amperes.
  • a transfer roll cooperating with an alternating current corona generator substantially minimizes hollow characters and insures that substantially the entire area of the toner powder image is transferred to the support material.
  • an alternating current corona generator spraying ions on the toner powder image facilitates transfer thereof by an electrically biased transfer roll.
  • this has been found to be particularly significant when a plurality of toner powder images are transferred from the photoconductive surface to the support material, in superimposed registration with one another.
  • the foregoing transfer apparatus reduces hollow characters on the support material, and transfers substantially the entire area developed on the electrostatic latent image to the support material.
  • An apparatus for transferring charged particles from a support surface to a sheet of support material including:
  • corona generating means disposed adjacent the support surface for applying an alternating charge potential to the support surface and the charged particles adhering thereto so as to substantially neutralize the attractive charge therebetween, thereby facilitating the transfer of the particles from the support surface, said corona generating means comprising an elongated shield defining an open-ended chamber and a corona discharge electrode mounted in the shield chamber;
  • a transfer member operatively associated with said corona generating means and having the sheet of support material secured thereto, said transfer member comprising a substantially cylindrical core of electrically conductive material and a plurality of layers of resilient material entrained about the cylindrical core with at least one layer of resilient material being substantially in contact therewith;
  • said corona generator means shield includes a substantially U-shaped member
  • said corona generator means discharge electrode includes a conductive coronode wire mounted in the chamber of the shield and extending substantially in a longitudinal direction along the length of the shield.
  • said energizing means excites said coronode wire at an alternating current ranging from about microamperes RMS to about 200 micro-amperes RMS. and preferably being about 1 l0 micro-ampcres RMS. said energizing means exciting said coronode wire at an alternating voltage ranging from about 3,000 volts RMS to about 5,000 volts RMS, and preferably being about 4,400 volts RMS.
  • coronode wire generates an alternating current output to the support surface having the charged particles thereon ranging from about 3.0 micro-amperes to about 5.0 micro-amperes, and being preferably about 4.0 micro-amperes.
  • bias applying means energizes said transfer member at a voltage ranging from about 1,500 volts to about 4,500 volts.
  • the resilient layers of said transfer member include: a first layer formed of a urethane material; and a second layer entrained about said first layer and formed of a polyurethane material.
  • An electrostatographic printing machine of the type wherein charged toner particles are transferred to a sheet of support material forming thereon a copy of the original document being reproduced including:
  • corona generating means disposed adjacent said image bearing member for applying an alternating charge potential to said image bearing member and the charged toner particles adhering thereto so as to substantially neutralize the attractive charge therebetween, thereby facilitating the transfer of the toner particles from said image bearing memher, said corona generating means comprising an elongated shield defining an open-ended chamber and a corona discharge electrode mounted in the shield chamber;
  • transfer member operatively associated with said corona generating means and having the sheet of support material secured releasably thereto, said transfer member comprising a substantially cylindrical core of electrically conductive material and a plurality of layers of resilient material entrained about the cylindrical core with at least one layer of resilient material being substantially in contact therewith;
  • said corona generator means shield includes a substantially U-shaped member
  • said corona generator means discharge electrode includes a conductive coronode wire mounted in the chamber of the shield and extending substantially in a longitudinal direction along the length of the shield.
  • coronode wire generates an alternating current output to said image bearing member having the charged particles thereon ranging from about 3.0 micro-amperes to about 5.0 micro-amperes. and being preferably about 4.0 micro-amperes.
  • a second layer entrained about said first layer and formed of a polyurethane material.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)
US00335968A 1973-02-26 1973-02-26 Transfer apparatus Expired - Lifetime US3838918A (en)

Priority Applications (11)

Application Number Priority Date Filing Date Title
US00335968A US3838918A (en) 1973-02-26 1973-02-26 Transfer apparatus
NL7401232A NL7401232A (fr) 1973-02-26 1974-01-29
CA191,682A CA1030400A (fr) 1973-02-26 1974-02-04 Dispositif de transfert
DE2405511A DE2405511C3 (de) 1973-02-26 1974-02-05 Verfahren zur Übertragung von Tonerbildern aus geladenen Teilchen
JP49019837A JPS6131460B2 (fr) 1973-02-26 1974-02-19
IT48552/74A IT1008903B (it) 1973-02-26 1974-02-20 Macchina stampatrice elettrostato grafica e relativa apparecchiatura di trasferimento di particelle cari che
BR1344/74A BR7401344D0 (pt) 1973-02-26 1974-02-22 Aparelho aperfeicoado para transferir particulas carregadas de um material suporte, e maquima de impressao eletrostatografica aperfeicoada
BE141264A BE811434A (fr) 1973-02-26 1974-02-22 Machine a imprimer electrostatographique
GB873374A GB1445243A (en) 1973-02-26 1974-02-26 Transfer ring charged particles to support material
FR7406475A FR2219452B1 (fr) 1973-02-26 1974-02-26
AU66033/74A AU6603374A (en) 1973-02-26 1974-02-26 Transfer apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00335968A US3838918A (en) 1973-02-26 1973-02-26 Transfer apparatus

Publications (1)

Publication Number Publication Date
US3838918A true US3838918A (en) 1974-10-01

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Application Number Title Priority Date Filing Date
US00335968A Expired - Lifetime US3838918A (en) 1973-02-26 1973-02-26 Transfer apparatus

Country Status (11)

Country Link
US (1) US3838918A (fr)
JP (1) JPS6131460B2 (fr)
AU (1) AU6603374A (fr)
BE (1) BE811434A (fr)
BR (1) BR7401344D0 (fr)
CA (1) CA1030400A (fr)
DE (1) DE2405511C3 (fr)
FR (1) FR2219452B1 (fr)
GB (1) GB1445243A (fr)
IT (1) IT1008903B (fr)
NL (1) NL7401232A (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3906501A (en) * 1974-08-09 1975-09-16 Rca Corp Apparatus for copying an electrostatic charge pattern in intensified form
US3920325A (en) * 1974-09-09 1975-11-18 Xerox Corp Moisture stable bias transfer roll
US3934549A (en) * 1974-08-01 1976-01-27 Xerox Corporation Transfer apparatus
US3994579A (en) * 1975-05-14 1976-11-30 Xerox Corporation Transfer system for electrophotographic printing
US4053216A (en) * 1975-01-13 1977-10-11 Xerox Corporation Color transparency reproducing machine
US4712906A (en) * 1987-01-27 1987-12-15 Eastman Kodak Company Electrostatographic apparatus having a transfer drum

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5175451A (ja) * 1974-12-25 1976-06-30 Lotte Co Ltd Seidenfukushaki
JP3033312U (ja) * 1996-07-08 1997-01-21 白十字株式会社 ガーゼマスク

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3492476A (en) * 1968-03-18 1970-01-27 Xerox Corp Electrostatic charging device utilizing both a.c. and d.c. fields
US3612677A (en) * 1969-06-04 1971-10-12 Xerox Corp Electrostatic transfer apparatus
US3697171A (en) * 1970-12-23 1972-10-10 Xerox Corp Simultaneous image transfer
US3729311A (en) * 1971-07-15 1973-04-24 Xerox Corp Electrostatic transfer method

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1540697A (fr) * 1966-10-11 1968-09-27 Rank Xerox Ltd Appareil de reproduction xérographique
JPS5411701B1 (fr) * 1969-06-04 1979-05-17

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3492476A (en) * 1968-03-18 1970-01-27 Xerox Corp Electrostatic charging device utilizing both a.c. and d.c. fields
US3612677A (en) * 1969-06-04 1971-10-12 Xerox Corp Electrostatic transfer apparatus
US3697171A (en) * 1970-12-23 1972-10-10 Xerox Corp Simultaneous image transfer
US3729311A (en) * 1971-07-15 1973-04-24 Xerox Corp Electrostatic transfer method

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3934549A (en) * 1974-08-01 1976-01-27 Xerox Corporation Transfer apparatus
US3906501A (en) * 1974-08-09 1975-09-16 Rca Corp Apparatus for copying an electrostatic charge pattern in intensified form
US3920325A (en) * 1974-09-09 1975-11-18 Xerox Corp Moisture stable bias transfer roll
US4053216A (en) * 1975-01-13 1977-10-11 Xerox Corporation Color transparency reproducing machine
US3994579A (en) * 1975-05-14 1976-11-30 Xerox Corporation Transfer system for electrophotographic printing
US4712906A (en) * 1987-01-27 1987-12-15 Eastman Kodak Company Electrostatographic apparatus having a transfer drum

Also Published As

Publication number Publication date
CA1030400A (fr) 1978-05-02
JPS49120646A (fr) 1974-11-18
DE2405511B2 (de) 1979-09-20
BR7401344D0 (pt) 1974-11-05
AU6603374A (en) 1975-08-28
DE2405511A1 (de) 1974-08-29
DE2405511C3 (de) 1980-06-04
FR2219452B1 (fr) 1978-03-24
JPS6131460B2 (fr) 1986-07-21
FR2219452A1 (fr) 1974-09-20
GB1445243A (en) 1976-08-04
IT1008903B (it) 1976-11-30
BE811434A (fr) 1974-06-17
NL7401232A (fr) 1974-08-28

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