US3711196A - Image transfer - Google Patents

Image transfer Download PDF

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Publication number
US3711196A
US3711196A US00879962A US3711196DA US3711196A US 3711196 A US3711196 A US 3711196A US 00879962 A US00879962 A US 00879962A US 3711196D A US3711196D A US 3711196DA US 3711196 A US3711196 A US 3711196A
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Prior art keywords
electrode
image
transfer
transfer member
particles
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US00879962A
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English (en)
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V Tulagin
L Carreira
I Stein
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Xerox Corp
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Xerox Corp
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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
    • 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
    • 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
    • G03G15/22—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20
    • G03G15/24—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 whereby at least two steps are performed simultaneously
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G17/00—Electrographic processes using patterns other than charge patterns, e.g. an electric conductivity pattern; Processes involving a migration, e.g. photoelectrophoresis, photoelectrosolography; Processes involving a selective transfer, e.g. electrophoto-adhesive processes; Apparatus essentially involving a single such process
    • G03G17/04—Electrographic processes using patterns other than charge patterns, e.g. an electric conductivity pattern; Processes involving a migration, e.g. photoelectrophoresis, photoelectrosolography; Processes involving a selective transfer, e.g. electrophoto-adhesive processes; Apparatus essentially involving a single such process using photoelectrophoresis

Definitions

  • the imaging particles which are generally intensely colored are suspended in an insulating carrier liquid. This suspension is then placed between a pair of electrodes, subjected to a potential difference and exposed to an image to be reproduced. Ordinarily, when carrying out the process, the imaging suspension is placed on a transparent electrically conductive plate in the form of a thin film and exposure is made through the bottom of this plate while a second electrode is brought into contact with the top of the suspension, while a potential is applied across the twoelectrodes.
  • the particles are believed to bear an initial charge when suspended in the liquid which causes them to be attracted to the transparent base electrode and to change polarity by exchanging charge with this base electrode upon exposure so that the exposed particles migrate across to the upper electrode to form an image on the base electrode by particle subtraction.
  • This image is clearly and easily visible on the base electrode after the upper electrode carrying the particles which are not used to form part of the image is separated from the base electrode.
  • the system may be used to produce monochromatic images by using a single color of particles in the suspension or a number of differently colored particles in the suspension which respond to the light exposure.
  • mixtures of two or more differently colored particles which are each sensitive only to light of a specific different wavelength or narrow range of wavelengths are used.
  • a full color image may be produced by using a mixture of cyan,
  • the electrophoretic imaging technique generally described above has been found to be capable of producing excellent quality images in both monochromatic and polychromatic systems, it is frequently undesirable to leave the final image on the transparent base electrode.
  • the use of a new electrode each time the imaging process is carried out might, make the process prohibitively expensive for
  • the electrode may not have any physical properties most desired as the final imaging substrate so that if the image is made on a conductive transparent glass substrate, it must be transferred to some other surface if a flexible print is to be produced. Although transfer of the image may be accertain applications.
  • the polarity of the applied field can be either positive or negative. In its preferred form however, the polarity of the applied field will be opposite to the polarity applied to the imaging electrode;
  • transfer electrode is positively charged, and vice versa. This is so because it is believed that the majority of the particles constituting the particle image are charged the same as the charge on the imaging electrode.
  • transfer step to improve, alter or otherwise modify transfer. Ithas been found, forexample, that 1 transfer from the base electrode onto the transfer substrate is more efficient when exposure of the image to the original being reproduced is continued during the transfer step. Transfer can also be effectedwhen the image is illuminated uniformly with white light during the transfer step. In another modification of the. process, filtered light of selected wavelengths may be used to expose the image during transfer for color correction or partial image transfer of polychromatic images using imaging particles of two or more colors.
  • Electrode 11 Coated on the upper surface of electrode 11 is a thin layer 14 of finely divided photosensitive particles dispersed in an insulatthe formed particle image and applying an electric field ing carrier liquid. This suspension may also contain binders for the particles whichare dissolved or suspended along with the particles in the carrier liquid. Adjacent electrode 11 is a roller electrode generally designated 16 mounted for rotation on a rigid plate 18.
  • Electrode 16 is connected in this instance to the negative side of a potential source 20 with the opposite side of the source being connected .to ground. Since the tin oxide layer of injecting electrode 11 is also connected to ground, an electric field is applied across the liquid suspension when electrode 16 rolls across the surface of electrode 11 in the direction indicated by the arrow 22in the drawing. Electrode 16 is made up of a central core 24 which is preferably of fairly high electrical con- .ductivity and this core is covered with a layer of a blocking electrode material 26, which may, for example, consist of Baryta paper (a paper coated with a gelatin suspension of barium sulphate).
  • An image projector made up of a light source 28, atransparency 30, and a lens 32 is provided to expose suspension 14 to a light image of the original transparency 30 'to be reproduced.
  • This electrode surface 26 collects unwanted (i.e. exposed) particles from suspension 14 as it rolls across electrode 11 during exposure,as explained in copending application Ser. No.'384,737, now US. Pat. No. 3,384,565 and leaves a particle image corresponding to the transparency to be reproduced on reused. It has been found that the particle image can be efficiently transferred to a more desirable surface by across the image in such a direction so as to transfer it to the transfer substrate.
  • Transfer electrode 34 is, in this embodiment, similar in constructionto electrode 16; that is, electrode 34 is made up of a conductive core 36 covered with a transfer surface 38, such as Baryta paper sleeve,
  • Conductive core 36 is connected by any suitable means to a potential source 40.
  • the potential applied to conductive core 36 is, in this embodiment, of opposite polarity to the potential applied to electrode 16;
  • electrode 34 is connected to the positive side of potential source 40 with the opposite side of the source being connected to ground. Since the tin oxide layer 13 on injecting electrode 11 is also con-' nected to ground, an electric field is applied across liquid suspension 14 when electrode 34 rolls across the surface of electrode '11 in the direction indicated by arrow 22in the Figure. In this manner, the particle image is cleanly transferred to transfer electrode 34. If transfer electrode 34 is covered with a: removable transfer surface, such as Baryta paper sleeve, for'example, as previously disclosed, the complete image is transferred to surface 38, which can then be removed and replaced with a new sleeve for use in subsequent transfers. After electrodes 16 and 34 have traveled across liquid suspension 14 in the directionindicated by arrow 22, they are raised slightly and returned to their initial position along the path indicated by arrow 42. Y
  • F IG. 2 shows an alternate embodimentof' the structure of transfer electrode 34.
  • transfer electrode 34 is made up'of a continuous web 44 of a conductive material having a'suitable transfer surface 45. Web 44 carried, by plate 18 in the form of by any suitable means, such as by a set of conductive rollers 50."
  • the electric field applied to the back of web' 44 is, once again, of opposite polarity to that of 'elec ⁇ trode 16 so that the particles left behind during the passage of electrode 16 are attracted to web 44.
  • FIG. 3 shows'an alternate embodiment of the manner in which the field is applied across the imaging suspension.
  • like numerals have been used to identifyparts of the apparatus which are identical to 2.
  • the embodiment shown here in FIG. 3 is the same as the FIG. 2 embodiment except for the'distinctions hereinafter noted, including the fact that the potential is applied to the back of transfer web 44 by means of high potential corona discharge device 52.
  • Such a' device is more fully described in 1 US. Pat. No. 2,588,699.
  • Rollers 54' are used to keep the transfer web surface under tension sufficient to maintain the transfer surface in a flat condition, whereby its entire applicable surface is placed in direct contact with liquidsuspension 14 during the transfer step.
  • each potential source 20 and 40 is individuallygrounded rather than having their opposite poles connected and then grounded as in FIG. 2
  • the polarity of the potential applied to electrode 34 is the same as the polarity of the potential applied to electrode 16.
  • the polarity of the applied field can be either positive or negative.
  • an imaging apparatus isshown wherein the polarity of the field applied to the transfer electrode is negative (i.e., the same polarity as is applied to the imaging electrode).
  • FIG. 4 represents a side sectional view of an embodiment of the invention after imaging electrode 16 has rolled over the exposed photosensitive suspension.
  • imaging electrode 16 is of the tractor type having aconductive inner web 56 covered with a layer of blocking electrode material 58, such as Baryta paper.
  • Electrode 16 is connected to the negative side of a potential source 20 by means of roller contacts 60 and plate contact 62.
  • the roller contacts also perform the auxiliary function of holding surface 58 under tension sufficient to maintain that surface in a flat condition, thereby enabling the entire applicable surface to be placed in direct contact with exposed suspension 14 as electrode 16 rolls thereover during the imaging operation.
  • electrode 16 has been caused to roll across the top surface of injecting electrode 11 during the period of image exposure.
  • transfer may be aided by flooding particle image 14' uniformly with white light during transfer. This can be accomplished by rotating original transparency 30 around pivot 64 (see FIG. 4) so that it is out of the path of the white light emanating from source 28.
  • transfer can be effected by electrode 34 while image 14 is subject to actinic electromagnetic radiation having a single wavelength or a selected band of wavelengths, which can be accomplished by any suitable means, for example, by rotating transparency 30 about pivot 64 out of the path of illumination from light source 28 and moving filter 66, also pivoted about point 64 for convenience into said illumination path.
  • actinic electromagnetic radiation having a wavelength (or a selected band of wavelengths) at which the particles in suspension 14 are equally responsive or as nearly equally responsive as nature permits.
  • the suspension comprises a dispersion of phthalocyanine, Algol Yellow, andWatchung Red in a liquid carrier, (as described in Ser. No. 384,737 now U.S. Pat. No. 3,384,565)
  • effective transfer occurs when the particle image is flooded with blue light of approximately 400 m.p.. wavelength.
  • a relatively low intensity light of correct wavelength is far more effective than white light (whose absolute intensity made the orders of magnitude greater, yet produces less than complete transfer).
  • transfer can be effected by electrode 34 while image 14' is subjected to actinic electromagnetic radiation which is passed through both transparency 30 and filter 66, thereby resulting in imagewise illumination of a particular wavelength (or a selected band of wavelengths only).
  • image 14' is formed by the passage of electrode 16 over the surface of injecting electrode 11, the image may look to be off color (i.e., imbalanced) because of an unexpected photoresponse in one or more of the particles in suspension 14. For example, if the image is viewed in white light and it appears to be too red, this is because the cyan particles responded too readily to the original exposure so that there are not enough cyan I particles left behind in image 14' to filter out the proper amount of red light from the white light source. To remedy this color imbalance, it will be necessary to transfer magenta and yellow particles to the transfer electrode 34 at a relatively lower rate than cyan particles are transferred.
  • this color correction can be achieved by illuminating image 14 with a light source which is deficient in the color (or 7 colors) cotresponding to the particle (particles) which an analgous manner, if the image appears to betoo blue when viewed in white light, transfer is conducted while the image is subjected to illumination from a light source which is deficient in blue light (e.g., by passing white light through a yellow filter) and if the image appears to be too green, then transfer is conducted'while the image is illuminated with a light source which is deficient in green light (e.g., by passing white light through a magenta filter). Passage of electrode 34 over image 14' during such illumination, while under a potential of opposite polarity to the potential applied to the imaging electrode, will result in the transfer of an image, in proper color balance, to the surface of the transfer electrode. Y
  • an imbalanced color image can be color corrected by selectively transferring, at a relatively greater rate, the remaining photosensitive particles corsystem are reversed, electrode 11 will preferably be capable of accepting injected holes from bound particles upon exposure tolight and electrode 16 would preferably be a blocking electrode incapable of injecting holes into the particles at more than a very slow rate when they come into contact with the surface of this 7 electrode.
  • electrode ll may be composed not only of conventional conductive materials such as'tin oxide, copper, copper iodide, gold or the like, but may also include many semiconductive materials such as raw'cellophane which are not ordina'rily thought of asconductors, but which are.
  • this selective transfer with the resultant color correction of the final image can be achieved by exposing image 14 during transfer to illumination which, is rich in red light (e.g., by passing a the transfer of an image, in proper color balance, to the surface of the -transfer electrode.
  • illumination which, is rich in red light
  • more cyan particles will be transferred (in a relative nature) than yellow particles or magenta particles and, in so do-,
  • the use of the more conductive materials is preferred because it allows for cleaner charge separation in that charge leaving the particles upon exposure can move into the underlying surface and away from the particle in which it originated. This also prevents'possible charge build-up on the electrode which might tend to diminish the inter-electrode field;
  • the preferredembodiment of the blocking electrode 16 isselectedso as to prevent or greatly retard the injection of electrons (or holes, depending upon the initial polarity of charge on the particle) into a bound particle when it reaches the surface of this electrode.
  • the surface of this electrode facing suspension 14 in the preferredembodiment may be either an insulator or a semiconductor I which will not allow for the passage of sufficient charge mg, image '14 will be brought back into color balance. 7
  • this blocking electrode will allow for the passage of some charge carriers through it to the particles, will still be considered to come within the class of preferred materials if it does not allow for the passage of sufficient carriers to recharge the particles to the opposite polarity because even a discharge particle will tend to adhere to this blocking electrode by Van Der Waals forces.
  • suitable material having aresistivity of about l0 ohm cm. or greater may be. employed, as a preferred. material- Typical materials in thisr'esistivity range -inwill not adversely affect the transfer of the particle image to the transfer electrode.
  • EXAMPLEl A suspension including 1.5 grams of Watchung Red B, a barium salt of 1-(4'-methyl-5-chloro-azobenzene- 2-sulfonic acid )-2-hydroxy-3-naphthoic a'cid, C.l. No. 15865, available from DuPont; 2 grams Algol Yellow o.c., l,2,5,6-di(C,C-diphenyl)-thiazole-anthraquinone, C.l. No. 67300, available from General Dyestuffs; and 1.5 grams Monolite Fast Blue G.S., the alpha form of metal-free phthalocyanine, C.l. No.
  • Sohio Odorless Solvent 3440 a kerosene fraction available from Standard Oil Company of Ohio. These particles are magenta, yellow, and cyan respectively.
  • This mixture known as tri-mix, is coated on a NESA glass substrate and exposed with a light intensity of 1,800 foot candles. A Kodachrome color transparency is placed between the light source and the NESA glass substrate so that a colored image is projected onto this tri-mix as the imaging electrode moves across the surface of the glass.
  • the imaging electrode has a polyvinylidene fluoride covering thereon and the roller is held at a negative potential of 2,500 volts with respect to the glass substrate.
  • a Baryta paper covered transfer electrode which is employed is held at a positive potential of 2,500 volts with respect to the glass substrate. After the transfer electrode passes over the remaining particle image left behind on the glass, a
  • Example ll The procedure of Example I is repeated including exposure of the particle image during transfer to uniform white light from the 1,800 foot candle light source.
  • Example IV The procedure of Example I is repeated except that the Baryta paper covered transfer electrode is held at a negative potential of 2,500 volts with respect to the glass substrate. The poor quality image is obtained on the transfer surface.
  • Example V The procedure of Example IV is repeated including exposure of the particle image during transfer to uniform white light from the 1,800 foot candle light source. A good quality image is obtained on the transfer surface.
  • Example V1 The procedureof Example V1 is followed with the further step of exposing the particle image during transfer to uniform white light from the800 foot candle light source. A good quality image is obtained on the Baryta paper transfer surface.
  • Example V111 The procedure of Example V1 is followed with the additional operation of exposing the particle image during transfer 'to light which has passed through the original Kodachrome color transparency. A superior quality image is obtained on the surface of the Baryta paper transfer paper.
  • Example V1 The procedure of Example V1 is followed except that approximately 2 mol percent 2,4,7-trinitro-9- fluorenone sensitizer is added to the tri-mix suspension.
  • a good quality image is obtained on the NESA glass substrate when a light source of 250 foot candles is vused.
  • a good quality image is also obtained on the Baryta paper transfer surface when the particle image is exposed to the 250 foot candle light source during transfer.
  • EXAMPLE X A suspension including equal amountsof Watchung Red B, Algol Yellow GC and Monolite Fast Blue GS is 7 made up in Sohio solvent with total particle concentrationapproximately percent by weight. This mixture is coated on a NESA glass substrate and exposed with a light intensity'of 1,800 foot candles. A Kodachrome color transparency is passed between the light source thereon and is held at a negative potential of 2,500
  • a Baryta paper covering transfer electrode which is employed is held at a positive potential of 2,500 volts with respect to the glass substrate.
  • a suspension including 1.0 grams of Watchung Red B, 1.5 grams of the yellow particle of Example V and 1.25 grams Monolite Fast Blue 0.8. is made up in 50 milliliters Sohio Odorless Solvent 3440. Theprocedure of Example X is followed except that the Baryta paper covering transfer electrode is held at a negative potential of 2,500 volts with respect tothe glass substrate.
  • Example V1 The procedure of Example V1 is followed with the further step of exposing the particle image during transfer to blue light of approximately, 400 m.p.. wavelength. This exposure is achieved by passing white light from the 800 foot candle source through a Wra't ten blue filter. A superior quality image is obtained on the Baryta paper transfer surface.
  • a photoelectrophoretic imaging apparatus comprising a smooth optically transparent first electrode for supporting a layer of an imaging suspension comprising electrically photosensitive particles in an insulating carrier liquid, a second electrode for uniformly contacting the free surface of an imaging suspension on said first electrode, means for applying a potential difference between said first and said second electrodes, means for exposing a suspension on said first electrode through said first electrode to radiation to which at least a portion of the particles in the imaging suspension are responsive until an image is formed on said first electrode, a transfer member for contacting an image on said first electrode, means for applying a potential difference between said transfer member and said first electrode, means for exposing an image on said first electrode to only a portion of the wavelengths in the visible light spectrum while said transfer member is in contact with the image.
  • said transfer member comprises a conductive support having a semiconductive covering thereon.
  • a photoelectrophoretic imaging apparatus com prising a smooth optically transparent first electrode for supporting a layer of an imaging suspension comprising electrically photosensitive particles in an insulating carrier liquid, a second electrode for uniformly contacting the free surface of an imaging suspension on said first electrode, means for applying a potential difference between said first and said second electrodes, means for exposing a suspension on said first electrode through said first electrode to radiation to which at least a portion of the particles in the imaging suspension are responsive until an image is formed on said first electrode, a transfer member for contacting an image on said first electrode, means for exposing an image on said first electrode to visible light which is less intense in at least one portion of the visible spectrum while said transfer member is in contact with the image.
  • said transfer member comprises a conductive support having an insulated covering thereon.
  • said transfer member comprises a conductive support having a semiconductive covering thereon.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Molecular Biology (AREA)
  • Optical Filters (AREA)
  • Electrochromic Elements, Electrophoresis, Or Variable Reflection Or Absorption Elements (AREA)
  • Color Electrophotography (AREA)
US00879962A 1966-04-12 1969-12-04 Image transfer Expired - Lifetime US3711196A (en)

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US54205066A 1966-04-12 1966-04-12
US87996269A 1969-12-04 1969-12-04

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US3711196A true US3711196A (en) 1973-01-16

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US (1) US3711196A (enrdf_load_stackoverflow)
BE (1) BE696853A (enrdf_load_stackoverflow)
CH (1) CH482230A (enrdf_load_stackoverflow)
ES (1) ES339049A1 (enrdf_load_stackoverflow)
GB (1) GB1185931A (enrdf_load_stackoverflow)
NL (1) NL6705032A (enrdf_load_stackoverflow)
SE (1) SE332754B (enrdf_load_stackoverflow)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4894686A (en) * 1987-08-31 1990-01-16 Olin Hunt Specialty Prod Transfer roller
US5045892A (en) * 1987-09-30 1991-09-03 Asahi Kogaku Kogyo Kabushiki Kaisha Recording paper transport mechanism
US5148228A (en) * 1988-10-17 1992-09-15 Asahi Kogaku Kogyo Kabushiki Kaisha Image recording apparatus

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2968552A (en) * 1956-10-01 1961-01-17 Haloid Xerox Inc Xerographic apparatus and method

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2968552A (en) * 1956-10-01 1961-01-17 Haloid Xerox Inc Xerographic apparatus and method

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4894686A (en) * 1987-08-31 1990-01-16 Olin Hunt Specialty Prod Transfer roller
US5045892A (en) * 1987-09-30 1991-09-03 Asahi Kogaku Kogyo Kabushiki Kaisha Recording paper transport mechanism
US5148228A (en) * 1988-10-17 1992-09-15 Asahi Kogaku Kogyo Kabushiki Kaisha Image recording apparatus
US5168317A (en) * 1988-10-17 1992-12-01 Asahi Kogaku Kogyo Kabushiki Kaisha Image recording apparatus including record medium edge holder

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DE1572384B2 (de) 1973-02-08
DE1572384A1 (de) 1970-02-12
SE332754B (enrdf_load_stackoverflow) 1971-02-15
BE696853A (enrdf_load_stackoverflow) 1967-09-18
NL6705032A (enrdf_load_stackoverflow) 1967-10-13
ES339049A1 (es) 1968-07-01
GB1185931A (en) 1970-03-25
CH482230A (fr) 1969-11-30

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