US3877417A - Transfer corona generating device with support brushes - Google Patents

Transfer corona generating device with support brushes Download PDF

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Publication number
US3877417A
US3877417A US406509A US40650973A US3877417A US 3877417 A US3877417 A US 3877417A US 406509 A US406509 A US 406509A US 40650973 A US40650973 A US 40650973A US 3877417 A US3877417 A US 3877417A
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US
United States
Prior art keywords
support surface
generating device
transfer member
corona generating
forcing
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
US406509A
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English (en)
Inventor
Lothar S Jeromin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xerox Corp
Original Assignee
Xerox Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Xerox Corp filed Critical Xerox Corp
Priority to US406509A priority Critical patent/US3877417A/en
Priority to CA207,775A priority patent/CA1026148A/en
Priority to DE2442162A priority patent/DE2442162A1/de
Priority to NL7412275A priority patent/NL7412275A/xx
Priority to FR7432463A priority patent/FR2247759B1/fr
Priority to JP49116020A priority patent/JPS5067661A/ja
Priority to GB4401174A priority patent/GB1463564A/en
Priority to AU74355/74A priority patent/AU7435574A/en
Application granted granted Critical
Publication of US3877417A publication Critical patent/US3877417A/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
    • G03G15/163—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

  • Energization of the corona generating device causes the de- [56] References Cited veloped image to be transferred to the transfer mem- UN1TED STATES PATENTS ber' 3,003,462 10/1961 Streich, s1. 117 175 x 15 Claims, 2 Drawing Flghres TRANSFER CORONA GENERATING DEVICE WITH SUPPORT BRUSHES BACKGROUNDHOFTHE INVENTION
  • a xerographic surface comprising a layer of photoconductive insulating material affixed to a conductive backing is used to support electrostatic images.
  • the xerographic plate is electrostatically charged uniformly over its surface and then ex posed to a light pattern .of the image being reproduced to thereby discharge the charge in the areas where light strikes the layer.
  • the undischarged areas of the layer thus form an electrostatic charge pattern in conformity with the configuration of the original light pattern.
  • the latent electostatic image can then be developed by contacting it with a finely divided electrostatically attractable material such as a powder.
  • a finely divided electrostatically attractable material such as a powder.
  • the powder is held in image areas by the electrostatic charge on the layer. Where the charge is greatest, the greatest amount of material is deposited; and where the charge is least, little or no material is deposited.
  • a pow der image is produced in conformity with the light image of the copy being reproduced.
  • the powder is subsequently transferred to a sheet of paper or other surface and suitably affixed thereto to form a permanent print.
  • any electrostatic latent image formed on a support surface may be developed in a similar manner as described hereinabove.
  • an electrostatic pattern can be printed on an insulating medium by means of a pin matrix, energization of selected pins applying a desired latent electrostatic image to the medium.
  • the latent electrostatic image is made visible by developing the image with powder, the developed image being transferred to a suitable transfer medium if so desired.
  • One prior art technique for transferring a developed image to a transfer medium utilizes a corona discharge device.
  • the transfer medium makes contact with the surface supporting the developed image, the powder forming the image being of a first polarity.
  • the corona discharge device produces a charge of opposite polarity on the free surface of the transfer medium, thereby tacking the transfer medium against the image bearing surface and simultaneously attracting the powder image from the image bearing surface to the transfer medium.
  • corona transfer techniques are deficient in certain respects. For example, vibration of the corona wire or dirt accumulation on the wire can cause a variation in ionization whereby uneven toner transfer may be observable on the transfer medium. Additionally, the efficiency of the corona discharge varies widely with environmental conditions. If an air gap is maintained between the powder image and the transfer medium, transfer is usually inefficient and incomplete.
  • the electrostatic tacking described hereinabove is not sufficient to bring the transfer medium into contact with the surface supporting the developed image, producing an air gap with attendant inefficient and incomplete imagetransfer.
  • the present invention provides improved apparatus for transferring developed images from a support surface to a transfer medium.
  • a plurality of support brushes are mounted to a corona generating, or transfer charging, device to force the transfer medium into substantially uniform contact with the support surface.
  • the electrostatic charge produced by the device and the contact established between the transfer medium and the support surface transfers the developed image to the support surface efficiently and completely.
  • a corona generating device includes a plurality of brushes mounted thereon, the brushes forcing the transfer medium into contact with the support surface, the electrostatic charge produced by the corona generating device and the contact established between the transfer medium and the support surface transferring substantially all of the developed image to the transfer medium.
  • FIG. 1 is a perspective view of the corona generating device of the present invention.
  • FIG. 2 is a schematic view of an electrophotographic transfer station which utilizes the apparatus of the pres ent invention.
  • the highvoltage wire 16 is stretched between and attached to blocks 18 and 20 of suitable insulating material which are arranged between the sidewalls 14 and attached at the ends of the shield by means of suitable fastening.
  • the insulating block 20 has attached thereto a conducting element 26 to which one end of the highvoltage-wir'e 18 is connected, by screw 28, the conducting element being disposed for engagement with a suitable conducting bar or source carrying a high-voltage supply as usual in this class of device.
  • the opposite end of the conducting wire 16 is attached to an insulating block 18 by screw 30.
  • sidewalls 14 include members 32 and 34, which together with sidewalls 14, form a channel, or recess, along the length of the sidewalls.
  • Brush means 40 and 42 each comprising a plurality of fibers, are secured in their respective channels in any suitable inanner, such as by crimping sidewalls 14.
  • the bottom of the brush fibers are mounted in retaining means 44 and 46, respectively, which are inserted in their associated channels.
  • the brush fibers are comprised of a non-conducting material, such as nylon, dynel or rayon.
  • Alternately conductive material, such as steel or graphite, for example, may be used for the brush fibers.
  • the thickness of the fiber material selected is such that damage to the image forming surface and the transfer medium, described with reference to FIG. 2, is prevented. Further, the thickness of the individual fibers is small so that a substantially constant force can be exerted by the brush fibers on the transfer medium so that intimate contact with the image surface can be produced without regard to the density of the toner, or developer,”particles in the different portions of the developed image.
  • the fibers extend substantially outward from the retaining means44 and 46 and are of substantially uniform length.
  • a brushmaterial which has been successfully utilized is nylon, the fibers having a length of approximately inch and a thickness of approximately 5 mils.
  • Additional desired characteristics of the brush material fibers are that they be flexible and should not react with ozone, a gaseous by-product of air ionization.
  • FIG. 2 illustrates the corona generating device of FIG. 1 at the transfer station of an electrophotographic station.
  • an electrophotographic plate 50 comprising an electrophotographic photoconductive member 52 overlying conductive substrate 54 is transported in the direction of arrow 55 by guide rollers 59 and 61.
  • Roller 61 should be selected such that it does not harm the surface of photoconductive member 52.
  • the present invention may be utilized in any system requiring the transfer of a developed powder image to a transfer medium, the invention is particularly adapted for use in the medical diagnostic area and in particular may be used in the xeroradiographic apparatus described in U.S. Pat. No. 3,650,620.
  • FIG. 2 illustrates the invention in highly schematical form
  • the plate transport means, the transfermedium transport and removal means as will be described hereinafter may utilize the mechanisms shown in the aforementioned patent which perform the corresponding functions.
  • the surface of photoconductive member 52 has a developed powder, or tonerimage 62, formed thereon corresponding to a latent'electrostatic image applied to photoconductive member 52 at a preceding information recording or imaging station.
  • the particular steps of developing a latent electrostatic image are well known and are described, for example, in the aforementioned U.S. Pat. No. 3,650,620 and'also in U.S. Pat No. 3,640,246.
  • the latent electrostatic image has been developed prior to being transported to the transfer area shown in FIG. 2. I
  • a transfer medium such as copy paper 66, is guide in an arcuate directionby guide member 68 and transported by rollers 70 and 72 into contact with the surface of photoconductive member 52 above corona generating device 10.
  • the transfer medium 66 is guided in an arcuate direction by guide member 68 towards the surface of photoconductive member 52 and the plate is transported in the direction of arrow by rollers 59 and 61.
  • Brush members 40 and 42 are initially positioned such that the fiber tips interfere with the surface of photoconductive member 52 whereby the transfer medium 66 is moved into intimate contact with the surface of photoconductive member 52 as plate 50 is transported in the direction of arrow 55.
  • the brushes 40 and 42 provide uniform contact at' substantially constant pressure between the transfer medium 66 and the surface of photoconductive member 52 over a band of contact, or contact area, determined by the spacing between the brushes 40 and 42 Energization of high-voltage wire 16 by applying a potential of the proper polarity to conducting element 26 causes the powder, or toner, image on the surface of photoconductive member 52 to be transferred to the surface of transfer medium 66 in contact therewith.
  • the present invention is useful in the field of medical diagnostics.
  • the art of X-ray recording by xerography generally known as xeroradiography
  • xeroradiography has been utilized in the field of medical diagnostics to examine, for example, the extremities.
  • Apparatus for automatically providing a permanent print, or xerogram, of the examined extremity is described in U.S. Pat. No. 3,650,620.
  • the transfer medium for the permanent print is of a thickness (i.e., 0.008 mils) which is generally greater than that utilized in the normal electrophotographic (i.e., xerographic) process.
  • the increased thickness prevents efficient transfer of the toner image to the transfer medium using corona generating transfer techniques.
  • the present invention allows the use of this technique byforcing the transfer medium into intimate contact with the surface of the photoconductive member 52 as the free surface of the transfer medium is charged to the proper polarity.
  • the leading edge of the transfer medium comes into contact with a gripper bar assembly 82 (more fully described in the aforementioned U.S. Pat. No. 3,650,620) which strips the transfer medium 66 from plate 50 to deliverit to another operational area whereat the transferred image may be fused to the transfer medium.
  • Apparatus for transferring a developed image formed on a support surface to a transfer member comprising:
  • a corona generating device located adjacent said support surface
  • corona generating device includes a pair of sidewalls said brush means comprising a pair of brushes, each of said brushes being supported adjacent a sidewall.
  • said brush means comprises a plurality of non-conductive fibers, the tips of said fibers forcing said transfer member into contact with said support surface.
  • Apparatus for transferring a developed image formed on a support surface to a transfer member comprising:
  • corona generating device located adjacent said support surface, said corona generating device comprising a housing including a pair of sidewalls and a bottom wall, a corona wire supported within said housing and means supported at each sidewall and extending substantially along the length thereof for forcing a transfer member into contact with said support surface,
  • each of said brush means comprises a plurality of nonconductive fibers, the tips of said fibers forcing said transfer member into contact with said support surface.
  • Apparatus for transferring a developed image formed on a support surface to a transfer member comprising:
  • corona generating device located adjacent said support surface, said corona generating device comprising a housing having a pair of sidewalls and a bottom wall, each sidewall having channel forming members associated therewith which extend along the length of the sidewall, a corona wire supported within said housing and means secured within each channel for forcing a transfer member into contact with said support surface,
  • each of said brush means comprises a plurality of nonconductive fibers, the tips of said fibers forcing said transfer member into contact with said support surface.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)
US406509A 1973-10-15 1973-10-15 Transfer corona generating device with support brushes Expired - Lifetime US3877417A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
US406509A US3877417A (en) 1973-10-15 1973-10-15 Transfer corona generating device with support brushes
CA207,775A CA1026148A (en) 1973-10-15 1974-08-26 Transfer corona generating device with support brushes
DE2442162A DE2442162A1 (de) 1973-10-15 1974-09-03 Vorrichtung zum uebertragen eines entwickelten elektrostatischen bildes
NL7412275A NL7412275A (ja) 1973-10-15 1974-09-16
FR7432463A FR2247759B1 (ja) 1973-10-15 1974-09-26
JP49116020A JPS5067661A (ja) 1973-10-15 1974-10-08
GB4401174A GB1463564A (en) 1973-10-15 1974-10-10 Transfer corona generating device with support brushes
AU74355/74A AU7435574A (en) 1973-10-15 1974-10-15 Generating device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US406509A US3877417A (en) 1973-10-15 1973-10-15 Transfer corona generating device with support brushes

Publications (1)

Publication Number Publication Date
US3877417A true US3877417A (en) 1975-04-15

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US406509A Expired - Lifetime US3877417A (en) 1973-10-15 1973-10-15 Transfer corona generating device with support brushes

Country Status (8)

Country Link
US (1) US3877417A (ja)
JP (1) JPS5067661A (ja)
AU (1) AU7435574A (ja)
CA (1) CA1026148A (ja)
DE (1) DE2442162A1 (ja)
FR (1) FR2247759B1 (ja)
GB (1) GB1463564A (ja)
NL (1) NL7412275A (ja)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4171899A (en) * 1976-12-13 1979-10-23 Ricoh Co., Ltd. Transfer apparatus
US4330349A (en) * 1980-10-02 1982-05-18 Xerox Corporation Method for preparing conductive fiber 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
US4553191A (en) * 1982-12-03 1985-11-12 Xerox Corporation Static eliminator
US4571052A (en) * 1984-05-31 1986-02-18 Fuji Xerox Co., Ltd. Electric field transfer method and apparatus
US4761709A (en) * 1984-10-29 1988-08-02 Xerox Corporation Contact brush charging
EP0411574A2 (en) * 1989-07-31 1991-02-06 Mita Industrial Co. Ltd. Electrophotographic image-forming method
US5884134A (en) * 1996-06-19 1999-03-16 Ricoh Co., Ltd. Image forming apparatus with a device to increase contact area between a transfer sheet and an image carrier

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59144670U (ja) * 1983-03-18 1984-09-27 株式会社リコー 記録装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3003462A (en) * 1957-01-18 1961-10-10 Bruning Charles Co Inc Apparatus for applying developer powder to photo-conductive insulating sheets
US3105770A (en) * 1960-04-15 1963-10-01 Xerox Corp Cascade development improvement
US3263649A (en) * 1962-04-19 1966-08-02 Agfa Ag Apparatus for developing electrostatic images
US3332328A (en) * 1965-03-01 1967-07-25 Xerox Corp Xerographic developer seal and process
US3691993A (en) * 1970-11-23 1972-09-19 Ibm Apparatus for transferring developed image
US3806391A (en) * 1970-10-01 1974-04-23 Gen Dynamics Corp Method of insulating

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3003462A (en) * 1957-01-18 1961-10-10 Bruning Charles Co Inc Apparatus for applying developer powder to photo-conductive insulating sheets
US3105770A (en) * 1960-04-15 1963-10-01 Xerox Corp Cascade development improvement
US3263649A (en) * 1962-04-19 1966-08-02 Agfa Ag Apparatus for developing electrostatic images
US3332328A (en) * 1965-03-01 1967-07-25 Xerox Corp Xerographic developer seal and process
US3806391A (en) * 1970-10-01 1974-04-23 Gen Dynamics Corp Method of insulating
US3691993A (en) * 1970-11-23 1972-09-19 Ibm Apparatus for transferring developed image

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4171899A (en) * 1976-12-13 1979-10-23 Ricoh Co., Ltd. Transfer apparatus
US4363550A (en) * 1979-12-06 1982-12-14 Tokyo Shibaura Denki Kabushiki Kaisha Recording sheet separating device in a transfer-type electronic copying machine
US4330349A (en) * 1980-10-02 1982-05-18 Xerox Corporation Method for preparing conductive fiber brushes
US4553191A (en) * 1982-12-03 1985-11-12 Xerox Corporation Static eliminator
US4571052A (en) * 1984-05-31 1986-02-18 Fuji Xerox Co., Ltd. Electric field transfer method and apparatus
US4761709A (en) * 1984-10-29 1988-08-02 Xerox Corporation Contact brush charging
EP0411574A2 (en) * 1989-07-31 1991-02-06 Mita Industrial Co. Ltd. Electrophotographic image-forming method
EP0411574A3 (en) * 1989-07-31 1992-11-19 Mita Industrial Co. Ltd. Electrophotographic image-forming method
US5884134A (en) * 1996-06-19 1999-03-16 Ricoh Co., Ltd. Image forming apparatus with a device to increase contact area between a transfer sheet and an image carrier
US6101361A (en) * 1996-06-19 2000-08-08 Ricoh Co., Ltd. Image forming apparatus with a device and a method to increase contact area between a transfer sheet and an image carrier

Also Published As

Publication number Publication date
FR2247759B1 (ja) 1977-07-08
GB1463564A (en) 1977-02-02
JPS5067661A (ja) 1975-06-06
FR2247759A1 (ja) 1975-05-09
NL7412275A (ja) 1974-12-30
DE2442162A1 (de) 1975-04-17
CA1026148A (en) 1978-02-14
AU7435574A (en) 1976-04-29

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