US3898082A - Method of making a transparency of a colored image in a magneto-electric printing system - Google Patents

Method of making a transparency of a colored image in a magneto-electric printing system Download PDF

Info

Publication number
US3898082A
US3898082A US254301A US25430172A US3898082A US 3898082 A US3898082 A US 3898082A US 254301 A US254301 A US 254301A US 25430172 A US25430172 A US 25430172A US 3898082 A US3898082 A US 3898082A
Authority
US
United States
Prior art keywords
photoconductive layer
particles
image
magnetic field
transparency
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
US254301A
Other languages
English (en)
Inventor
Jr Edward Charles Giaimo
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.)
RCA Corp
Original Assignee
RCA 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 RCA Corp filed Critical RCA Corp
Priority to US254301A priority Critical patent/US3898082A/en
Priority to CA170,532A priority patent/CA1005509A/en
Priority to SE7306681A priority patent/SE376313B/xx
Priority to AU55602/73A priority patent/AU461508B2/en
Priority to BE131095A priority patent/BE799514A/xx
Priority to NL7306793A priority patent/NL7306793A/xx
Priority to JP48054541A priority patent/JPS5147620B2/ja
Priority to FR7317780A priority patent/FR2330042A1/fr
Priority to DE2324813A priority patent/DE2324813C3/de
Priority to IT24190/73A priority patent/IT987646B/it
Priority to GB2363273A priority patent/GB1373208A/en
Application granted granted Critical
Publication of US3898082A publication Critical patent/US3898082A/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
    • G03G13/00—Electrographic processes using a charge pattern
    • G03G13/01—Electrographic processes using a charge pattern for multicoloured copies
    • G03G13/016—Electrographic processes using a charge pattern for multicoloured copies in which the colour powder image is formed directly on the recording material, e.g. DEP methods
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G13/00—Electrographic processes using a charge pattern
    • G03G13/06—Developing
    • G03G13/08—Developing using a solid developer, e.g. powder developer
    • G03G13/09—Developing using a solid developer, e.g. powder developer using magnetic brush

Definitions

  • a transparency of a colored image is produced on a light-transmitting recording element, comprising a photoconductive layer and a tricolor mosaic filter layer, by a single-exposure method wherein (a) the photoconductive layer is uniformly charged electrostatically and uniformly covered with magneto-electric particles; (b) a magnetic field of a strength just insufficient to remove the particles from the photoconductive layer is applied adjacent to the particles; and (c) the photoconductive layer is exposed through the tricolor mosaic filter, while in the magnetic field, with a light image of the colored image to be produced.
  • a transparency of a colored image on a light-transmitting recording element is produced with the aid of magneto-electric particles in a manner whereby the colored image may be visually monitored during its formation; and the image can be viewed, when formed, without removing the color transparency from a combined exposure, development and viewing station.
  • the magneto-electric particles may be erased from the recording element, if so desired, with the same apparatus used for developing the recording element, and without the necessity of removing the recording element from the exposure, development, and viewing station.
  • the novel method of making a transparency ofa colored image on a light-transmitting recording element. comprising a photoconductive layer and a tricolored mosaic filter layer, comprises the steps of: (a) charging the photoconductive layer uniformly, (b) covering the charged photoconductive layer uniformly with magneto-electric particles, (c) applying a magnetic field adjacent to the uniformly toned photoconductive layer, the magnetic field being of a strength just insufficient to remove the particles from the photoconductive layer, and (d) while in the magnetic field, exposing the uniformly covered photoconductive layer through the filter layer with a colored light image of the colored image to be produced on the color transparency.
  • FIG. I is a schematic illustration of a sideelevational view of a light-transmitting recording element used in the novel method
  • FIG. 2 is a schematic view of one form of a tricolor mosaic filter layer viewed in the direction of lighttransmission;
  • FIGS. 3, 4, 5, and 6 are schematic illustrations of the recording element, shown in FIG. 1, in sequential operations of being electrostatically charged, covered with magneto-electric particles, exposed, and viewed, respectively, in aecordance with the novel method.
  • the recording element I0 comprises a light-transmitting substrate 12, a tricolored mosaic filter layer 14 on a major surface 16 of the substrate 12, a light-transmitting, electrically conductive layer 18 on a major surface 20 of the filter layer I4, and a photoconductive layer 22 on a major surface 24 of the conductive layer 18.
  • the light-transmitting substrate 12 may be rigid or flexible and may comprise a light-transmitting material, such as glass or a flexible plastic material, such as Mylar" or Cronar (E. I. DuPont De Nemours Co., Wilmington, Del),
  • the electrically conductive layer 18 may comprise a Iighttransmitting, thin film of a metal, such as aluminum or chromium, for example, or a transparent layer of tin oxide and/or indium oxide.
  • the photoconductive layer 22 should be responsive to all of the colors in the visible spectrum and comprises a photoconductive layer of a light-transmitting material of the type described in US. Pat. No. 3,484,237, for Organic Photoconductive Compositions and Their Use in Electrophotographic Processes, or in the aforementioned US. Pat. No. 3,458,309, both patents being incorporated herein by reference.
  • a light-transmitting recordingelement comprising a layer of dye-sensitized particulate zinc oxide in a resin binder may also be used.
  • the filter layer 14 may comprise a multiplicity of systematically, or randomly, arranged minute colored areas of a substantially equal number of each ofthree primary colors, designated as R, G, and B for the colors red, green, and blue, respectively.
  • the elemental colored areas of the filter layer 14 illustrated in FIG. 2 are in a regular geometric pattern. A separate minute area of a primary color is provided for each elemental area of the image to be formed on a color transparency. Examples of the filter layer I4 and their method of manufacture are'described in the aformentioned US. Pat. No. 3,458,309 and US. Pat. No. 3,4l3,l l7, and are included herein by reference.
  • Color filter layers having a more or less statistically random distribution of irregularly shaped primary colored areas are described in the aformentioned patents.
  • the maximum transverse dimension of each separate color R, G, or B area should be less than about 0.005 inch.
  • means are provided to electrostatically charge the photoconductive layer 22, in darkness, with a uniform electrostatic charge.
  • the conductive layer 18 of the recording element 10 is connected to a source of reference potential. such as ground. and a corona discharge device 26 of the type commonly used in the electrophotographic printing art, is disposed between the outer major surface 28 of the photoconductive layer 22 of the recording element 10.
  • the corona discharge device 26 has a corona generating element 28, such as a thin wire. connected to the positive terminal of a high-voltage. unidirectional power supply 30.
  • the negative terminal of the power supply is connected to ground. as is the shield 31 ofthe corona discharge device 26.
  • the high voltage power supply 30 is capable of providing at least 5.000 volts.
  • the corona discharge device 26 is adapted to be moved over the recording element 10 in the directions of the double-headed arrow 32 to provide the photoconductive layer 22 with a uniform electrostatic charge.
  • the corona discharge device 26 connected as shown in FIG. 3, the surface 28 of the photoconductive layer 22 is charged positively, in darkness. It is also within the scope of the present invention to charge the surface 28 negatively.
  • the uniformly charged surface 28 of the photoconductive layer 22 is next covered, in darkness. uniformly with magneto-electric particles 34. as shown in FIG. 4.
  • the magneto-electric particles 34 are attracted electrostatically to the electrostatically charged surface 28.
  • the magneto-electric particles 34 comprise particles of magnetic material that may. or may not. be coated with a thermoplastic adhesive of any desired color.
  • magneto-electric particles as used herein. is meant particles of materials that are capable of being moved by both a magnetic field and an electric field. either separately or concurrently.
  • the magnetoelectric particles 34 may comprise nickel, cobalt. or iron particles. for example. capable of being moved by a magnetic and/or an electric field.
  • the average diameter of the magneto-electric particles 34 is not critical and may be between and 30 microns.
  • the magnetoelectric particles 34 do not necessarily have to be spherical in shape. Suitable magneto-electric particles 34 for the novel method are described in US. Pat. Nos. 3,526.19l; 3,l06.479; and 3.093.039. for example.
  • the magneto-electric particles 34 need not have an electroscopic charge thereon because electrostatically neutral magneto-electric toner particles 34 are attracted to a charged surface by what is believed to be electrostatic induction.
  • the magneto-electric particles 34 may be applied to the surface 28 by cascading them over the surface 28 from a container 36 held over an inclined recording element 10, as shown in FIG. 4. Other means of applying the magneto-electric particles 34 uniformly to the surface 28 may be employed. such as by passing the uniformly charged recording element l0 through a trough of magneto-electric particles 34.
  • Means are provided to expose. at an exposure station. the uniformly covered recording element with a single exposure of a colored light image of the image desired on the color transparency to be formed by the recording element 10.
  • a colored light image as. for example. from a color transparency 38. such as a photographic Kodachromc" slide transparency. is projected (by directing white light onto the transparency 38) through the substrate 12, the color filter layer 14. and the conductive layer 18 onto the photoconductive layer 22, as shown in FIG. 5.
  • the colored image on the tranparency 38 may comprise blue. red. black. green. and white portions. as indicated in FIG. 5.
  • the projected blue. red. and green portions of the image of the transparency 38 will pass through blue. red. and green areas. respectively. of the tricolor mosaic filter layer 14 of the recording element 10.
  • any black portions of the transparency 38 will not pass through any of the colored areas of the filter layer 14'. and the projected white light of the transparency 38 will pass through each of the red. green. and blue areas upon which it impinges on the filter layer 14.
  • the primary component colors of a color other than a primary color are transmitted through the appropriate primary colors of the filter layer 14.
  • a magnetic field of a strength just insufficient to remove the particles 34 from the surface 28 of the recording element 10, in the absence of any exposure of the recording element 10, is disposed adjacent the surface 28.
  • an electromagnet 40 in the form of a toroid is disposed adjacent to the surface 28 to provide a substantially uniform magnetic field just insufficient to remove the magneto-electric particles 34 from the surface 28 in the absence of any exposure of the recording element 10.
  • the electromagnet 40 is energized from a suitable source 42 of electrical energy. such as a battery. connected through a single-pole single-throw switch 44 and a rheostat 46.
  • the proper strength of a desired magnetic field adjacent to the surface 28 of the photoconductor 22 is obtained by closing the switch 44 and adjusting the rheostat 46.
  • the photoconductive layer 22 is exposed by light from the colored image of the transparency 38, the electrostatic attraction between the magncto-electric particles 34 and the photoconductive layer 22 at the exposed portions is reduced; and the affected magneto-electric particles 34 are removed from the exposed areas of the photoconducti e layer 22 by the magnetic field. as shown in FIG. 5.
  • the amount of magnetoelectric particles 34 that are removed by the exposure of any elemental area of the photoconductive layer 22 is proportional to the intensity of light of the exposure thereat.
  • the exposure and development (selective removal of some particles 34 from the surface 28) of the recording element 10, at the developing station. as shown in Flg. 5, may be monitored by an observer viewing the image being formed on the surface 28 by looking through the opening 48 in the toroid of the electromagnet 40 during the exposure process.
  • the exposure may be extinguished. as by turning off the white light that projects the colored image from the transparency 38 onto the recording element 10. and/or by opening the switch 44 and removing the magnetic field from adjacent the surface 28.
  • the colored image being devel oped on the surface 28 may also be monitored by projccting the image as it is formed. during the exposure period. onto a screen (not shown) with a suitable optical system (not shown.
  • the developed recording element 10 is a transparency of the colored image projected onto it from the transparency 38'. and this colored image may be viewed. like any photographic transparency. by directing uniform white light through the developed record ing element 10. as shown in FIG. 6.
  • the magnetoelectric particles 34 may be fixed to the surface 28 of the recording element by spraying a transparent adhesive onto the magneto-electric particles 34. if the magneto-electric particles 34 are coated with a thermoplastic material, they may be fixed to the surface 28 by heating them to meltthe thermoplastic coating so that vthe particles 34 may adhere to the surface 28.
  • the strength of the magnetic field may be increased so that all the magneto-electric particles 34 are pulled from the surface 28 without removing the recording element 10 from the exposure station.
  • the removal of the magneto-electric-particles 34 may also be enhanced by exposing the recording element 10 with white light, preferably through the filter layer 14, so as to increase the photoconductivity of the photoconductive layer 22. This procedure reduces the electrostatic attraction between the magneto-electric particles 34 and the photoconductive layer 22 so that the particles 34 may be removed easily by the magnetic field.
  • a method of making 'a transparency of a colored image on a light-transmitting recording element comprising a color-sensitive photoconductive layer and a tricolor mosaic filter layer, said filter layer comprising a multiplicity of systematically, or randomly, arranged minute colored areas ofa substantially equal number of each of three primary colors, and a separate minute area of a primary color being for each elemental area of said colored image, said method comprising the steps of:
  • an adjustable magnetic field adjacent to said uniformly covered photoconductive layer said magnetic field being adjusted to a strength just insufficient to remove said particles from said photoconductive layer, exposing said uniformly covered photoconductive layer, while in said magnetic field, with a colored light image of the image desired on the transpar' ency, to reduce the electrostatic attraction between the exposed portions of said photoconductive layer and certain magnetic particles thereat.
  • said adjustable magnetic field being applied adjacent said uniformly covered photoconductive layer with an electromagnet in the form of a toroid having an unobstructed opening therein, and observing said photoconductive layer through said unobstructed opening in said toroid during the step of exposing said photoconductive layer, and removing said certain magnetic particles whereby to monitor the development of the image on said transparency.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Photoreceptors In Electrophotography (AREA)
  • Electrophotography Using Other Than Carlson'S Method (AREA)
  • Developing Agents For Electrophotography (AREA)
US254301A 1972-05-17 1972-05-17 Method of making a transparency of a colored image in a magneto-electric printing system Expired - Lifetime US3898082A (en)

Priority Applications (11)

Application Number Priority Date Filing Date Title
US254301A US3898082A (en) 1972-05-17 1972-05-17 Method of making a transparency of a colored image in a magneto-electric printing system
CA170,532A CA1005509A (en) 1972-05-17 1973-05-07 Method of making a transparency of a colored image in a magneto-electric printing system
SE7306681A SE376313B (pm) 1972-05-17 1973-05-11
AU55602/73A AU461508B2 (en) 1972-05-17 1973-05-11 Method of making a transparency ofa colored image ina magneto-electric printing system
BE131095A BE799514A (fr) 1972-05-17 1973-05-14 Procede pour faire un element transparent d'une image en couleurs dans un systeme d'impression magneto-electrique,
JP48054541A JPS5147620B2 (pm) 1972-05-17 1973-05-16
NL7306793A NL7306793A (pm) 1972-05-17 1973-05-16
FR7317780A FR2330042A1 (fr) 1972-05-17 1973-05-16 Procede pour faire un element transparent d'une image en couleurs dans un systeme d'impression magneto-electrique
DE2324813A DE2324813C3 (de) 1972-05-17 1973-05-16 Verfahren zum Herstellen eines Transparentbildes nach einem Mehrfarbenbild
IT24190/73A IT987646B (it) 1972-05-17 1973-05-16 Metodo di fabbricazione di una trasparenza di una immagine a colori in un sistema di stampa magnetoelettrico
GB2363273A GB1373208A (en) 1972-05-17 1973-05-17 Method of making a transparency of a coloured image in a magneto- electric printing system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US254301A US3898082A (en) 1972-05-17 1972-05-17 Method of making a transparency of a colored image in a magneto-electric printing system

Publications (1)

Publication Number Publication Date
US3898082A true US3898082A (en) 1975-08-05

Family

ID=22963739

Family Applications (1)

Application Number Title Priority Date Filing Date
US254301A Expired - Lifetime US3898082A (en) 1972-05-17 1972-05-17 Method of making a transparency of a colored image in a magneto-electric printing system

Country Status (11)

Country Link
US (1) US3898082A (pm)
JP (1) JPS5147620B2 (pm)
AU (1) AU461508B2 (pm)
BE (1) BE799514A (pm)
CA (1) CA1005509A (pm)
DE (1) DE2324813C3 (pm)
FR (1) FR2330042A1 (pm)
GB (1) GB1373208A (pm)
IT (1) IT987646B (pm)
NL (1) NL7306793A (pm)
SE (1) SE376313B (pm)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4291109A (en) * 1979-11-26 1981-09-22 Eastman Kodak Company Additive color imaging using a silverless recording element
US4604337A (en) * 1983-11-28 1986-08-05 Olympus Optical Co., Ltd. Electrophotographic color copying paper and copying method making use of the same
US4613555A (en) * 1983-11-30 1986-09-23 Matsushita Electric Industrial Co., Ltd. Image forming method using electrically conductive, light transmissive particles
US4696880A (en) * 1984-09-06 1987-09-29 Konishiroku Photo Industry Co., Ltd. Method and apparatus for reproducing multi-color image and photoreceptor thereof

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5753755A (en) * 1980-09-18 1982-03-30 Canon Inc Electrophotographic receptor

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2798959A (en) * 1953-10-01 1957-07-09 Rca Corp Photoconductive thermography
US2924519A (en) * 1957-12-27 1960-02-09 Ibm Machine and method for reproducing images with photoconductive ink
US2968552A (en) * 1956-10-01 1961-01-17 Haloid Xerox Inc Xerographic apparatus and method
US3093039A (en) * 1958-05-12 1963-06-11 Xerox Corp Apparatus for transferring powder images and method therefor
US3392642A (en) * 1963-02-15 1968-07-16 Germer Horst Apparatus for printing
US3413117A (en) * 1965-07-16 1968-11-26 Gen Electric Color electrophotography employing a three color filter and thermoplastic materials
US3707138A (en) * 1970-12-14 1972-12-26 Eastman Kodak Co Apparatus for transferring a developed image from a photosensitive member to a receiver

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE790678A (fr) * 1971-10-29 1973-02-15 Rca Corp Procede de formation d'une image sur un support d'impression electrophotographique

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2798959A (en) * 1953-10-01 1957-07-09 Rca Corp Photoconductive thermography
US2968552A (en) * 1956-10-01 1961-01-17 Haloid Xerox Inc Xerographic apparatus and method
US2924519A (en) * 1957-12-27 1960-02-09 Ibm Machine and method for reproducing images with photoconductive ink
US3093039A (en) * 1958-05-12 1963-06-11 Xerox Corp Apparatus for transferring powder images and method therefor
US3392642A (en) * 1963-02-15 1968-07-16 Germer Horst Apparatus for printing
US3413117A (en) * 1965-07-16 1968-11-26 Gen Electric Color electrophotography employing a three color filter and thermoplastic materials
US3707138A (en) * 1970-12-14 1972-12-26 Eastman Kodak Co Apparatus for transferring a developed image from a photosensitive member to a receiver

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4291109A (en) * 1979-11-26 1981-09-22 Eastman Kodak Company Additive color imaging using a silverless recording element
US4604337A (en) * 1983-11-28 1986-08-05 Olympus Optical Co., Ltd. Electrophotographic color copying paper and copying method making use of the same
US4613555A (en) * 1983-11-30 1986-09-23 Matsushita Electric Industrial Co., Ltd. Image forming method using electrically conductive, light transmissive particles
US4696880A (en) * 1984-09-06 1987-09-29 Konishiroku Photo Industry Co., Ltd. Method and apparatus for reproducing multi-color image and photoreceptor thereof
US4839692A (en) * 1984-09-06 1989-06-13 Konishiroku Photo Industry Co., Ltd. Apparatus for reproducing multi-color image

Also Published As

Publication number Publication date
FR2330042A1 (fr) 1977-05-27
CA1005509A (en) 1977-02-15
NL7306793A (pm) 1973-11-20
DE2324813A1 (de) 1973-11-29
GB1373208A (en) 1974-11-06
IT987646B (it) 1975-03-20
FR2330042B1 (pm) 1978-04-28
DE2324813C3 (de) 1978-08-10
DE2324813B2 (de) 1977-12-15
SE376313B (pm) 1975-05-12
JPS4967629A (pm) 1974-07-01
AU5560273A (en) 1974-11-14
JPS5147620B2 (pm) 1976-12-16
AU461508B2 (en) 1975-05-29
BE799514A (fr) 1973-08-31

Similar Documents

Publication Publication Date Title
US2638416A (en) Developer composition for developing an electrostatic latent image
US3013890A (en) Process of developing electrostatic images and composition therefor
US2758525A (en) Electrostatic photographic printing
US2955938A (en) Xerography
US2962374A (en) Color xerography
US3117884A (en) Electrostatic printing process and apparatus
US3820985A (en) Method and apparatus for inductive electrophotography
US2962375A (en) Color xerography
US3615395A (en) Electrostatic and electrophotographic variable contrast image-forming methods
US2817598A (en) Continuous tone reversal development process
US2892973A (en) Apparatus for imparting electrostatic charges in electrophotography
US2970906A (en) Xerographic plate and a process of copy-making
US2979403A (en) Electrostatic printing
US3609031A (en) Method of forming electrostatic latent images
US3719481A (en) Electrostatographic imaging process
CA1091497A (en) Process for electrophotographic image formation by toner transfer using a corona
US3898082A (en) Method of making a transparency of a colored image in a magneto-electric printing system
US3288604A (en) Imaging method using an element having a glass overcoating
US3458309A (en) Color transparencies produced by electrophotographic techniques
US3836363A (en) Color electrophotography using a photoconductive layer on both sides of a multicolor screen
US3143508A (en) Developer for electrophotography
US2963365A (en) Electrostatic printing
US3935327A (en) Copying using pyroelectric film
US3196765A (en) Image development and projection
US3986872A (en) Method of increasing the image exposure and developing sensitivity of magneto-electric printing system