[go: up one dir, main page]

US3640249A - Transfer apparatus - Google Patents

Transfer apparatus Download PDF

Info

Publication number
US3640249A
US3640249A US872175A US3640249DA US3640249A US 3640249 A US3640249 A US 3640249A US 872175 A US872175 A US 872175A US 3640249D A US3640249D A US 3640249DA US 3640249 A US3640249 A US 3640249A
Authority
US
United States
Prior art keywords
support medium
transfer
electrically
isolated portions
outer peripheral
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
US872175A
Other languages
English (en)
Inventor
Eugene F Young
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
Application granted granted Critical
Publication of US3640249A publication Critical patent/US3640249A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • G03G15/1665—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 by introducing the second base in the nip formed by the recording member and at least one transfer member, e.g. in combination with bias or heat
    • G03G15/167—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 by introducing the second base in the nip formed by the recording member and at least one transfer member, e.g. in combination with bias or heat at least one of the recording member or the transfer member being rotatable during the transfer
    • G03G15/1685—Structure, details of the transfer member, e.g. chemical composition

Definitions

  • a SuPPon i 'f- 2 elffmically biased 96 C 1 SD L4; 95/1 A; 355/3 r0 er avrng an outer penp er su ace of electrically isolated segments of a conductive resilient material is positioned [56] References Cited ad acent the electrical charge carrying surface with the support medium passing therebetween.
  • the electrically isolated UNITED TATES NTS conductive segments are selectively actuated in response to the length of the support medium to effect transfer of the eleclg; 18/637 troscopic toner particles thereto to the exclusion of effecting 2 889 758 6/1959 Balm 5 transfer of the toner particles to the transfer roller surface.
  • a TTORNEY TRANSFER APPARATUS BACKGROUND OF THE INVENTION This invention relates to apparatus for transferring electroscopic toner particles to a support medium and, in particular, to an electrically biased transfer roller positioned adjacent an electroscopic toner particle bearing surface with a support medium passing therebetween to effect transfer of the particles to the support medium.
  • this invention relates to an electrically biased transfer roller having an outer peripheral surface comprising electrically isolated conductive rubber segments selectively actuated to effect transfer of the toner particles to the support medium without transferring toner particles onto the transfer roller per se.
  • Another system for effecting the transfer of toner particles to a support medium is an electrically biased transfer roller utilized in place on the ion-producing filaments disclosed in the Carlson patent.
  • a transfer apparatus is disclosed in C. J. Fitch, U.S. Pat. No. 2,807,233 and comprises a transfer roller including an inner metallic portion and a outer portion of a very resilient or yielding material with a high electrical resistance, as for example a layer of soft semiconducting rubber having an electrical resistivity of approximately ohms. per cubic centimeter.
  • An electrically biased transfer roller offers certain advantages over an ion-producing source, such as a corotron, in that the transfer efficiency of the electroscopic toner powder to the support medium is more efficient and less sensitive to relative humidity.
  • a further and very important advantage is that a reference point can be established to allow a sequential transfer of images to a single support medium in registration.
  • Such a registered sequential transfer is useful in color-reproducing systems wherein an original document is imaged onto a photoreceptor through optical color separation filters to form a series of latent images which are developed by the application of electroscopic toner powder in accordance with the color separation to create a reproduction of the original document.
  • the series of color separated electroscopic toner powder images are sequentially transferred to a support medium before becoming permanently affixed thereto. During the sequential transfer of these images, the registration of one color separated image relative to another is an extremely critical parameter.
  • Another object of this invention is to effect transfer of toner powder to a support medium without transferring the powder to portions of the electrode roller devoid of support material.
  • Still another object of this invention is to electrically isolate selective portions of the transfer roller to effect image transfer in response to the selectively actuated electrically isolated portions.
  • an electrically biased transfer roller for transferring electroscopic toner particles to a support medium and having an outer peripheral surface of electrically isolated conductive segments selectively actuable to effect transfer of the electroscopic toner particles in accordance with the electrical bias on the isolated segments.
  • FIG. 1 is a perspective mechanical schematic of an automatic xerographic reproducing machine utilizing the, invention of this application.
  • FIG. 2 is an enlarged portion of the apparatus shown in FIG. 1 to better illustrate the features of the electrically biased transfer roller.
  • FIG. 1 there is shown a mechanical schematic of an automatic xerographic reproducing machine utilizing an electrically biased transfer roller 50 constructed in accordance with this invention.
  • the photoreceptive surface 1 is uniformly charged by means of an ion emitting device 2 and exposed to a light image 3 of a document to be reproduced creating an electrostatic latent image on or in the photoreceptive surface.
  • the electrostatic latent image is then developed 4 by applying electroscopic toner to the latent image, illustrated by a cascade development apparatus of a type well known in the art.
  • the electroscopic toner powder image formed thereby is forwarded through a transfer station 5 whereat an electrically biased transfer roller 50 effects transfer of the electroscopic toner powder image from the photoreceptive surface onto a support medium 10 illustrated as a sheet of paper.
  • the electroscopic toner powder image transferred to thesupport surface is forwarded beneath a fixing device 6 whereat the toner power is permanently affixed to the paper, and the photoreceptor l is rotated through a cleaning station7 hereat any residual toner powder remaining on the photoreceptive surface is removed and the surface reconditioned for another cycle as is well known in the xerographic art.
  • the electrically biased transfer roller 50 comprises an innermetallic portion 51 and an outer portion 52 of very resilient or yielding material having a high electrical resistance, as for example, a layer of soft semiconducting rubber.
  • the conductive rubber is preferably a very poor conductor of electricity and may have an electrical resistivity of approximately 10 ohms. per cubic centimeter.
  • the transfer roller 50 is mechanically biased in the direction of the photoreceptor l with the support material 10 passing therebetween.
  • the outer peripheral surface comprises electrically isolated portions 55, 56 and S7.
  • the portions 55, 56 and 57 of the roller surfaces are electrically isolated from one another by means of thin pieces of dielectric or insulating material such as mylar extending the length of the roller.
  • a suitable electrical contact surface 54 is provided on the end of potions 56 and 57 for a purpose to be hereinafter described in detail.
  • the circumference of the arc of portion 55 is substantially ll inches
  • the arc of the portion 56 is substantially 3 inches
  • the arc of portion 57 is substantially 1 inch with the entire circumference of the transfer roller being approximately l4 inches.
  • the electroscopic toner powder image is thereat transferred from the photoreceptor to the support medium in registration therewith by control of a registration gate 70 which functions to register and synchronize the position of support material 10, transfer roll 50 and the toner powder image to insure that the leading edge of the support material arrives at point X at the time the leading edge of the toner powder image on the photoreceptor is at that position.
  • the support medium is, for example, a sheet of paper 11 inches in length
  • only electrically isolated portion 55 is electrically biased to attract the toner powder to the support medium. This portion is continuously electrically biased during machine operation through the transfer roller shaft.
  • electrically isolated portions 56 and 57 are not energized, or are energized with an electrical charge of a polarity the same as the electroscopic toner powder to prevent the toner powder from transferring to these surfaces.
  • the portion 55 of the transfer roller which is continuously energized, and the electrically isolated portion 56 are energized to effect image transfer through 13 inches of the rollers circumference.
  • the electrically isolated portion 57 would not be energized or would be energized with an electrical bias of a polarity the same as the electroscopic toner powder to prevent offsetting of toner powder onto the roller surface.
  • a solenoid SOL-1 is carried by a support member 65 and positioned adjacent the transfer roller.
  • the plunger of the solenoid is mechanically coupled to a suitable electrical contact 66 through an insulator 67 such that upon energization of the solenoid the plunger is extended to couple with the suitable contact surface 54 on the portion 56 at the transfer zone whereat portion 56 is most immediate the photoreceptor.
  • a sensor 90 is positioned adjacent the drum shaft to send the rotational position of the transfer roller and to control the energization of the solenoid to extend the plunger energizing the electrically isolated portion 56 only when that portion is passing adjacent the photoreceptor.
  • a sheet of support material is forwarded by a sheet feeding apparatus and registered against registration stops 70 to be forwarded into contact with point X in registration with an image fonned on the photoreceptor.
  • the rotational position of the transfer roller is determined by the sensor 90, in accordance with any conventional manner such as a limit switchdetent or photocell system, and functions to release the registration gate and energize the solenoid SOL-l to apply the power supply to the portions 56 and/or 57 in accordance with the length of the support medium.
  • This actuation of the solenoid may be preset by a controller such as a timer actuated in response to the rotational position of the roller determined by sensor 90.
  • the transfer roller 50 and, therefore, the outer peripheral surface portion 55 is connected to a suitable power supply, for example 1,000 volts, of a polarity opposite that of the charge on the electroscopic toner powder through the roller shaft 59.
  • the power supply creates an electric field between the transfer roller 50 and the conductive plate of the photoreceptor l to cause the electroscopic toner powder adhering to the photoreceptor to transfer onto the support medium.
  • a second power supply of the same magnitude and polarity is coupled to contact 66 carried by the plunger of solenoid SOL-l and is applied to the portions 56 and/or 57 in accordance with the length of the support medium being utilized in the reproducin machine.
  • Apparatus for effecting the transfer of electroscopic toner powder to a support medium including a rotatable member having an outer peripheral surface of a highly electrical resistive material adapted toretain an electricalcharge,
  • said outer peripheral surface being divided into electrically isolated portions
  • Apparatus for effecting the transfer of electroscopic toner powder to a support medium including a rotatable member having n outer peripheral surface of a material capable of carrying an electrical charge,
  • said outer peripheral surface being divided into electrically isolated portions

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)
US872175A 1969-10-29 1969-10-29 Transfer apparatus Expired - Lifetime US3640249A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US87217569A 1969-10-29 1969-10-29

Publications (1)

Publication Number Publication Date
US3640249A true US3640249A (en) 1972-02-08

Family

ID=25358997

Family Applications (1)

Application Number Title Priority Date Filing Date
US872175A Expired - Lifetime US3640249A (en) 1969-10-29 1969-10-29 Transfer apparatus

Country Status (2)

Country Link
US (1) US3640249A (fr)
BE (1) BE758058A (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3877416A (en) * 1973-04-23 1975-04-15 Xerox Corp Humidity corrected transfer apparatus
US3924943A (en) * 1974-06-11 1975-12-09 Xerox Corp Segmented biased transfer member
US3993825A (en) * 1973-10-04 1976-11-23 Itek Corporation Electrophotographic toner transfer and fusing apparatus and method
US4739361A (en) * 1986-12-09 1988-04-19 Eastman Kodak Company Roller transfer apparatus
US5179397A (en) * 1989-04-03 1993-01-12 Canon Kabushiki Kaisha Image forming apparatus with constant voltage and constant current control

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2807233A (en) * 1954-03-29 1957-09-24 Ibm Electrophotographic printing machine
US2863063A (en) * 1955-11-21 1958-12-02 Bruning Charles Co Inc Charging of photo-conductive insulating material
US2889758A (en) * 1954-12-24 1959-06-09 Ibm Electrophotographic printer
US2912586A (en) * 1957-11-01 1959-11-10 Haloid Xerox Inc Xerographic charging
US3013526A (en) * 1958-06-16 1961-12-19 Xerox Corp Xerographic image transfer apparatus
US3124457A (en) * 1962-04-02 1964-03-10 Charge

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2807233A (en) * 1954-03-29 1957-09-24 Ibm Electrophotographic printing machine
US2889758A (en) * 1954-12-24 1959-06-09 Ibm Electrophotographic printer
US2863063A (en) * 1955-11-21 1958-12-02 Bruning Charles Co Inc Charging of photo-conductive insulating material
US2912586A (en) * 1957-11-01 1959-11-10 Haloid Xerox Inc Xerographic charging
US3013526A (en) * 1958-06-16 1961-12-19 Xerox Corp Xerographic image transfer apparatus
US3124457A (en) * 1962-04-02 1964-03-10 Charge

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3877416A (en) * 1973-04-23 1975-04-15 Xerox Corp Humidity corrected transfer apparatus
US3993825A (en) * 1973-10-04 1976-11-23 Itek Corporation Electrophotographic toner transfer and fusing apparatus and method
US3924943A (en) * 1974-06-11 1975-12-09 Xerox Corp Segmented biased transfer member
US4739361A (en) * 1986-12-09 1988-04-19 Eastman Kodak Company Roller transfer apparatus
US5179397A (en) * 1989-04-03 1993-01-12 Canon Kabushiki Kaisha Image forming apparatus with constant voltage and constant current control

Also Published As

Publication number Publication date
BE758058A (fr) 1971-04-27

Similar Documents

Publication Publication Date Title
US3847478A (en) Segmented bias roll
US3697171A (en) Simultaneous image transfer
US3837741A (en) Control arrangement for transfer roll power supply
US3976370A (en) Belt transfer and fusing system
US3759222A (en) Microfield donor with continuously reversing microfields
US4402593A (en) Grounding device for moving photoconductor web
GB1445671A (en) Transferring charged particles
US5233396A (en) Intermediate transfer member having a low surface energy compliant structure and method of using same
US3936174A (en) Transfer roller with stationary internal electrode
US3627523A (en) Multiple powder transfer in photoelectrostatic duplicator
US3687541A (en) Xerographic duplex technique
US3442645A (en) Electrophotographic method
US5028779A (en) Corona charging device
US3640249A (en) Transfer apparatus
US4292923A (en) Development system
US3838918A (en) Transfer apparatus
US4105320A (en) Transfer of conductive particles
US4454559A (en) Control for a corona discharge device
US4423951A (en) Roller transfer corona apparatus
JP3271811B2 (ja) 画像形成装置
US3954333A (en) Transfer roll having means for monitoring and controlling the resistivity thereof
US5729807A (en) Optically switched commutator scheme for hybrid scavengeless segmented electroded donor rolls
JPS6090357A (ja) 記録方法および装置
US4128328A (en) Developing electrode type electrostatic copying machines
US3866564A (en) Magnetic brush developing apparatus for copiers