US3784398A - Transferring recorded signals and latent electrostatic images before development - Google Patents

Transferring recorded signals and latent electrostatic images before development Download PDF

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Publication number
US3784398A
US3784398A US00172085A US3784398DA US3784398A US 3784398 A US3784398 A US 3784398A US 00172085 A US00172085 A US 00172085A US 3784398D A US3784398D A US 3784398DA US 3784398 A US3784398 A US 3784398A
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United States
Prior art keywords
image
transfer
dielectric constant
drum
sheet
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Expired - Lifetime
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US00172085A
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English (en)
Inventor
K Metcalfe
A Clements
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Commonwealth of Australia Department of Supply
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Commw Australia Secretary Depa
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    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03GELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02Charge-receiving layers
    • G03G5/0202Dielectric layers for electrography
    • G03G5/0205Macromolecular components
    • G03G5/0211Macromolecular components obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03GELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G13/00Electrographic processes using a charge pattern
    • G03G13/14Transferring a pattern to a second base
    • G03G13/18Transferring a pattern to a second base of a charge pattern
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03GELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02Charge-receiving layers
    • G03G5/0202Dielectric layers for electrography
    • G03G5/0205Macromolecular components
    • G03G5/0208Macromolecular components obtained by reactions only involving carbon-to-carbon unsatured bonds

Definitions

  • the invention relates to a method of and means for transferring recorded signals and latent electrostatic [30] Forelgn Apphcamfn pnomy Dam images before development.
  • the insulating medium Aug. 17, 1970 Australia 2214/70 which is placed over the photoconductor Surface i so constructed that the dielectric constant or permittivity [52] 117/175 96/1 96/1 on one side is lower than the dielectric constant on the 96/14, 7/37 LE other side.
  • This can be achieved by forming the insu- [51] G033 1 603g 13/10 003g 13/16 lating medium of a laminate of two differing materials [58] Field of Search 96/1 R, 1.3, 1.4;
  • the photoconductive surface is itself of a very high grade and highly expensive and to avoid the need of applying developer to this sensitive surface that process utilizes an insulating web which is placed over the photoconductive surface and the latent image so induced in the insulating web is then developed and the developed image is transferred to ordinary paper.
  • an object of the present invention therefore, is to provide a better method of and means for transferring latent electrostatic images and recorded signals while retaining a highlyeffective form of transfer to a medium on which the image can then be developed at the final medium as the developed image transferred to a further receiving member.
  • the principle underlying the invention is the attainment of a satisfactory gradient between the image recciving surface and the back of the insulator sheet according to which there is a change in polarization of the molecules through the sheet so that the good insulator surface at the receiving face holds the charge transferred to it without substantial leakage, while the layer near the other face serves to hold the charge against lateral transfer because of the enhanced polarization caused through the material having a greater dielectric constant or permittivity.
  • attention is directed to the dependence of dielectric effects or permittivity on polarization in an applied field, the applied field in this case being the latent image field which thus effects high level polarization in the area of the more distant layer because of the higher permittivity of this layer.
  • the side of the insulating medium which contacts the actual latent image is a good insulator with a lower dielectric constant than the other side, so that there is a gradient between them and thus for instance a machine can be produced which has a drum coated with a photoconductive medium, which can be of a relatively expensive type because it is merely used to produce a latent image and does not have to be contacted by a developer, but this drum is in turn in contact with a drum which has on its surface a medium of high insulating value but in the form of a laminate in which the outer layer has a lower dielectric constant or permittivity than the inner layer, whereupon it will be found that as the one drum rolls on the other, the image will be transferred to the transfer drum and can be developed thereon by a developer roller or the like in contact with the drum and the developed image can then be immediately transferred to paper or the like which passes between the transfer drum and a loading roller which presses the paper onto the drum and between which and the transfer drum a potential may be applied
  • the effectiveness of transfer of electrostatic images is very dependent on the quality of the surface of the recording member, for example the photoconductive drum or plate. It is possible according to this invention to use a cheap and expendable electrostatically coated drum as the photoconductive member and to have a suitable laminated drum or an insulator belt or sheet associated with this drum for the reception and retention of the latent transfer image, or alternatively instead of using the drum or belt or medium with the laminate construction to which the latent image is transferred, the image may be transferred to the paper itself provided the paper has on it a layer of polyvinyl-chloride or the like so that a smooth surface exists which is a good insulator with a relatively low dielectric constant and which is in contact with the photoconductive drum, enabling the transfer to be effected before development because of the better surface and because of the suitable dielectric properties.
  • FIG. 1 demonstrates the principle of the invention and shows how image transfer from a photoconductor sheet to an insulator sheet can be effected
  • FIGS. 2A-2E diagrammatically show the steps of the invention
  • FIG. 3 shows schematically a machine embodying the invention
  • FIG. 4 shows schematically how a transfer sheet which itself is a laminate may be processed to receive the latent image and the image can then be developed on this laminate.
  • FIG. 1 therein is seen a photoconductor sheet 1 which consists of a backing 2 with a photoconductor surface 3 there-on. This is the recording member.
  • This photoconductor surface has an image formed on it in any suitable manner such as by first charging the surface and then projecting a light image thereon and this latent electrostatic image is then transferred to transfer sheet 4 which forms an intermediate between the photoconductor sheet and the final copy sheet.
  • This sheet 4 is thus the transfer member.
  • This transfer sheet is a composite sheet having a good insulator 5 on one side with a relatively low dielectric constant, and an insulator 6 on the other side with a higher dielectric constant, the purpose of this being to provide a potential gradient between the two insulator membranes.
  • the insulator on the image receiving side has a dielectric constant of perhaps 2 while the other side has a dielectric constant of about 4, measured at 10 C.P.S.
  • the latent electrostatic image is removed from the photoconductor sheet and is held on the transfer sheet where it can then be developed by means of any of the normal xerographic methods.
  • FIGS. 2A-2E demonstrate the actual steps of a pro- I 1 now placed beneath a projector 14 which projects a light image onto it, the photoconductor sheet 1 being of course placed on a suitable support which is of a conductive nature, unless the photoconductor sheet backing is itself conductive, and the light then bleeds away the image at those areas where the light strikes the photoconductor sheetv which of course is maintained under dark room conditions from the time it is charged to the time the image has been formed and developed.
  • FIG. 2C shows the photoconductor sheet now turned over and placed onto a transfer sheet 4 which as shown in FIG. 1 is a composite sheet of good insulator properties, but of a lower dielectric constant on one side and a higher dielectric constant on the other, the lower dielectric surface being placed into contact with the photoconductor sheet, which action then transfers the latent electrostatic image from the photoconductor sheet 1 to the transfer sheet 4.
  • FIG. 2D shows a developer roller is now run over the transfer sheet to apply developer to the image according to where the developer is attracted to the sheet, and this transfer sheet 4 as shown in FIG. 2B is now brought into contact with a final copy sheet 17 or receiving member by the application of pressure or a potential which will ensure transfer of the developed image from the transfer sheet to the final copy sheet.
  • the developer roller 16 can of course be replaced by any convenient developer mechanism and development could be either by means of marking particles used in dry form or suspended in a carrier liquid of high electrical insulating characteristic so that during development it does not destroy the latent image on the transfer sheet.
  • the device of FIG. 3 utilizes an image producing station 20 which charges and light bleeds the photoconductor drum 21 in any convenient manner, the drum 21 being coated with selenium or any other suitable type of photoconductor, and obviously as it does not have developer applied to it, the initial costs of such a photoconductor drum is not a vital consideration as it is were an image is developed on same and much more expensive but more suitable photoconductors can be used for this purpose.
  • the drum 22 which is in contact with the photoconductor drum 21 has on it a compound insulator surface consisting of a lower dielectric constant material 23 which forms the outer part of the drum, and a higher dielectric material 24 which forms the inner part of the drum, so that here again there is a transfer member which has a dielectric gradient characteristic between the surface 23 and 24.
  • This arrangement will transfer any latent electrostatic image formed on the photoconductor drum to the transfer drum at the point of contact 25 between the drums, and this drum 22 then has the image developer on it at a developer station 26 where a developer roller 27 which dips into developer 28 in the tank 29 is brought into contact with the transfer drum 22.
  • a developer liquid nip 30 is formed forwardly of the point of contact between the transfer drum 22 and the developer roller 27 this ensuring that there is a high degree of turbulence at this point and a constant replenishing of the developer, but as the developer roller is in firm contact with the transfer drum 22, excess developer is removed from the drum and only the image is left on the transfer drum after it passes the developer station, with very little dampness due to the liquid developer.
  • a second transfer station 32 now transfers the developed image to a paper or other web 33, which is taken from a roll 34 and passes over a pressure roller 35 which urges the paper or similar member into contact with the transfer drum 22, and at this stage the still damp developed image is accepted by the paper web or the like and the final transfer is achieved.
  • a cleaning station 37 is disposed between the second transfer station 32 and the first transfer station 25, so that the sequence is that a latent image is formed at the image station 20, on the photoconductor drum 21, which is then transferred at the transfer station 25 as a latent electrostatic image, to the transfer roller 22, but
  • the latent electrostatic image is developed so that the image is now changed from a latent electrostatic image to a developed image which leaves this station in a state so that at the second transfer sta tion the now developed image will be transferred to the paper web 33 or other convenient medium.
  • the photoconductor drum 40 has an image forming station 41 associated with it, and the latent image is transferred to a member 42 comprising a paper or other backing layer 43 having a layer 44 on it which receives the latent electrostatic image and which is of lower dielectric constant than the backing layer 43, the image being developed by the developer roller 45.
  • Rollers 46 and 47 press the member 42 against the photoconductor drum 40 and the developer roller 45 respectively.
  • the novel feature of the devices illustrated is the use of an intermediate transfer member having specific characteristic layers as described earlier herein, namely a layer which is a laminate of a relatively high insulating outer layer with a low dielectric constant and an insulating layer with a higher dielectric constant immediately beneath which receives the latent image as opposed to receiving a developed image.
  • the backing layer could be:
  • a method of transferring latent electrostatic images from a recording member to a receiving member comprising contacting the recording member with a transfer member to transfer the information thereon to the transfer member, said transfer member being formed as a Iaminateof two insulator layers, one being an image receiving layer having a relatively low dielectric constant, the other being a backing layer having ahigher dielectric constant, said image receiving layer being brought into contact with the recording member during said transfer of information, said image receiving layer being selected from the group consisting of polyvinyl chloride, vinyl chloride acetate copolymer, cellulose acetate butyrate, methylmethacrylate, epoxy, polyethylene and silicones, said backing layer being selected from the group consisting of melamine formaldehyde, phenol formaldehyde and styrene alkyd polyesters, developing the image on the transfer member, and transferring the thusly developed image from the transfer member to the receiving member.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)
  • Photoreceptors In Electrophotography (AREA)
US00172085A 1970-08-17 1971-08-16 Transferring recorded signals and latent electrostatic images before development Expired - Lifetime US3784398A (en)

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Application Number Priority Date Filing Date Title
AU221470 1970-08-17

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US3784398A true US3784398A (en) 1974-01-08

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Country Status (9)

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US (1) US3784398A (enrdf_load_stackoverflow)
JP (1) JPS5434337B1 (enrdf_load_stackoverflow)
BE (1) BE771432A (enrdf_load_stackoverflow)
CA (1) CA941004A (enrdf_load_stackoverflow)
DE (1) DE2140955A1 (enrdf_load_stackoverflow)
FR (1) FR2104435A5 (enrdf_load_stackoverflow)
GB (1) GB1362863A (enrdf_load_stackoverflow)
NL (1) NL7111314A (enrdf_load_stackoverflow)
SE (1) SE356615B (enrdf_load_stackoverflow)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3949148A (en) * 1973-11-15 1976-04-06 Xerox Corporation Transparency for multi-color electrostatic copying
US4199356A (en) * 1974-02-01 1980-04-22 Mita Industrial Company Limited Electrophotographic process, of transferring a magnetic toner to a copy member having at least 3×1013 ohm-cm resistance
US4241134A (en) * 1979-05-24 1980-12-23 Gaf Corporation Electrostatically imageable drafting film
US4444847A (en) * 1979-06-25 1984-04-24 Kanzaki Paper Manufacturing Company, Limited Electrostatic record material
US5087539A (en) * 1988-07-28 1992-02-11 Victor Company Of Japan, Ltd. Method and apparatus for transferring an electrostatic latent image
US5099284A (en) * 1989-08-28 1992-03-24 Eastman Kodak Company Master sheet and drum assembly
US5177503A (en) * 1991-05-24 1993-01-05 Delphax Systems Print system and dielectric imaging member

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4362799A (en) * 1978-04-28 1982-12-07 Canon Kabushiki Kaisha Image-holding member with a curable epoxyacrylate resin insulating layer
CN113291068A (zh) * 2021-05-19 2021-08-24 沈超超 一种新型激光打印机及其使用方法
FR3136134A1 (fr) 2022-05-30 2023-12-01 Iptech Dispositif de communication bas coût RadCom, associant radars embarqués et communication inter-véhicules.

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2982647A (en) * 1956-06-14 1961-05-02 Haloid Xerox Inc Electrostatic image reproduction
US3551146A (en) * 1965-06-28 1970-12-29 Xerox Corp Induction imaging system
US3666458A (en) * 1968-11-25 1972-05-30 Kalle Ag Process for transferring electrostatic charge images
US3672930A (en) * 1970-04-02 1972-06-27 Eastman Kodak Co Process of transferring an electrostatic charge pattern without using external pressure or electrical bias

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2982647A (en) * 1956-06-14 1961-05-02 Haloid Xerox Inc Electrostatic image reproduction
US3551146A (en) * 1965-06-28 1970-12-29 Xerox Corp Induction imaging system
US3666458A (en) * 1968-11-25 1972-05-30 Kalle Ag Process for transferring electrostatic charge images
US3672930A (en) * 1970-04-02 1972-06-27 Eastman Kodak Co Process of transferring an electrostatic charge pattern without using external pressure or electrical bias

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3949148A (en) * 1973-11-15 1976-04-06 Xerox Corporation Transparency for multi-color electrostatic copying
US4199356A (en) * 1974-02-01 1980-04-22 Mita Industrial Company Limited Electrophotographic process, of transferring a magnetic toner to a copy member having at least 3×1013 ohm-cm resistance
US4241134A (en) * 1979-05-24 1980-12-23 Gaf Corporation Electrostatically imageable drafting film
US4444847A (en) * 1979-06-25 1984-04-24 Kanzaki Paper Manufacturing Company, Limited Electrostatic record material
US5087539A (en) * 1988-07-28 1992-02-11 Victor Company Of Japan, Ltd. Method and apparatus for transferring an electrostatic latent image
US5099284A (en) * 1989-08-28 1992-03-24 Eastman Kodak Company Master sheet and drum assembly
US5177503A (en) * 1991-05-24 1993-01-05 Delphax Systems Print system and dielectric imaging member

Also Published As

Publication number Publication date
SE356615B (enrdf_load_stackoverflow) 1973-05-28
JPS5434337B1 (enrdf_load_stackoverflow) 1979-10-26
NL7111314A (enrdf_load_stackoverflow) 1972-02-21
CA941004A (en) 1974-01-29
BE771432A (fr) 1971-12-31
FR2104435A5 (enrdf_load_stackoverflow) 1972-04-14
GB1362863A (en) 1974-08-07
DE2140955A1 (de) 1972-02-24

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