EP0060621A2 - Elektrophotographisches Kopieren - Google Patents

Elektrophotographisches Kopieren Download PDF

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Publication number
EP0060621A2
EP0060621A2 EP82300711A EP82300711A EP0060621A2 EP 0060621 A2 EP0060621 A2 EP 0060621A2 EP 82300711 A EP82300711 A EP 82300711A EP 82300711 A EP82300711 A EP 82300711A EP 0060621 A2 EP0060621 A2 EP 0060621A2
Authority
EP
European Patent Office
Prior art keywords
light
electrostatic latent
original document
sensitive member
latent image
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.)
Withdrawn
Application number
EP82300711A
Other languages
English (en)
French (fr)
Other versions
EP0060621A3 (de
Inventor
Takashi Miyagi
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 Ltd
Original Assignee
Rank Xerox Ltd
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
Priority claimed from JP56025388A external-priority patent/JPS57139757A/ja
Priority claimed from JP56025387A external-priority patent/JPS57139756A/ja
Application filed by Rank Xerox Ltd filed Critical Rank Xerox Ltd
Publication of EP0060621A2 publication Critical patent/EP0060621A2/de
Publication of EP0060621A3 publication Critical patent/EP0060621A3/de
Withdrawn legal-status Critical Current

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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

Definitions

  • This invention relates generally to a method of electrophotographic printing, and more particularly concerns reproducing an original document having information in two different colors.
  • a photoconductive surface is charged to a substantially uniform level.
  • the photoconductive surface is imagewise exposed to record an electrostatic latent image corresponding to the informational areas of the original document being reproduced.
  • a developer mixture is transported into contact with the electrostatic latent image.
  • Toner particles are attracted from the carrier granules of the developer mixture onto the latent image.
  • the resultant toner powder image is then transferred from the photoconductive surface to a copy sheet and permanently affixed thereto.
  • each developer unit contains discretely colored toner particles.
  • the light image of the colored original document is optically filtered to form a single color light image.
  • This single color light image creates a single color electrostatic latent image on the photoconductive surface.
  • the single-color electrostatic latent image is then developed with toner particles of a color complementary in color to the color of the filtered light image.
  • three single-color toner powder images are successively developed on the photoconductive surface.
  • Each single color toner powder image corresponds to the complement of one of the colors of the information contained in the original document.
  • These toner powder images are successively transferred to the copy sheet in superimposed registration with one another to form a multi-color copy corresponding to the original document being reproduced. Thereafter, the composite toner powder image is permanently affixed to the copy sheet.
  • Hauser et al. describes an electrophotographic printing machine in which two successive electrostatic latent images are formed on a photoconductive surface.
  • a first removable developer unit is initially loaded with developer material of one color for developing the first latent image therewith.
  • a second developer unit replaces the first developer unit and develops the second electrostatic latent image with developer material of another color.
  • the first electrostatic latent image is transferred to a copy sheet.
  • the second electrostatic latent image is transferred to the copy sheet.
  • both powder images have been transferred to the copy sheet, the powder images are permanently affixed thereto forming a color highlighted copy.
  • Aoki et al. discloses a process of electrophotographic printing in which the photoconductor is initially charged, imagewise exposed through a color filter in one of the three additive primary colors, and discharged by being charged to the opposite polarity or with an alternating current.
  • the photoconduetor is then uniformly illuminated with white light to record an electrostatic latent image thereon. Simultaneously with the imagewise exposure and discharge, the photoconduetor is exposed to infrared light rays.
  • a method of electrophotographic printing in which an original document having information in two different colors is reproduced.
  • a first electrostatic latent image corresponding to the information in one of the colors of the original document, and a second electrostatic latent image corresponding to the information in the other of the colors of the original document are recorded on a light-sensitive member.
  • the first electrostatic latent image and the second electrostatic latent image are of different polarities.
  • the first electrostatic latent image and the second electrostatic latent image are developed with marking particles having different polarities and colors.
  • the present invention relates to a two-color electrophotographic printing process, and, in particular, to a two-color image forming process wherein latent images corresponding to each color of a bicolor document are formed and developed with toner particles of different polarities.
  • the toner particles are of a color corresponding to the colors contained within the original document.
  • the resulting two-color toner powder image is then transferred to the copy sheet and subsequently permanently affixed thereto. In this way, a two-color copy is formed from the original document.
  • the process of obtaining two-color copies from an original document composed of two colors, e.g. black and red utilizes a light-sensitive member comprising a light-sensitive layer with an insulating layer being superimposed thereover.
  • the amount of charge remaining at the boundary between the insulating layer and the light-sensitive layer in the black portion, the red portion and the white portion is changed.
  • the potential in the white ground portion is adjusted to about 0 volts.
  • Electrostatic latent images having opposite polarities are formed in the black and the red portions.
  • the latent images are developed with the correspondingly colored toner particles. These toner particles have a polarity opposite to the polarity of the respective electrostatic latent images. In this way, a two-color toner powder image is developed on the light-sensitive member.
  • a light-sensitive member comprising a base plate 10, a light-sensitive layer 12 and an insulating layer 14 is initially charged.
  • base plate 10 is made from an electrically conductive material.
  • Light-sensitive layer 12 is made from a photoconductive material such as a selenium alloy.
  • Insulating layer 14 is made preferably from a high abrasion-resistant electrostatic charge-retentive material with high resistivity and transmissivity to the photoconductive layer. Examples of such material include polycarbonate resins, polyethylene resins and polyester resins, With continued reference to Figure 1, the light-sensitive member is negatively charged.
  • an original document 16 comprising black (B), red (R) and white (W) regions is illuminated and the resultant light image thereof transmitted through a cyan optical filter 18 onto the charged light sensitive member. Simultaneously therewith, the light-sensitive member is positively charged so that the net potential is about 0 volts in the white region with the potential in the red and black regions becoming a net positive.
  • original document 16 is re-exposed through red filter 20.
  • the red-filtered light image radiates the light-sensitive member and the positive charge leaves the interface in the red region converting it to a negative charge while the white region remains at about 0 - volts with the black region remaining positive.
  • two electrostatic latent images are recorded on the light-sensitive member, one having a positive polarity in the black region and the other a negative polarity in the red region.
  • FIG 4 there is shown development of the negative and positive electrostatic latent images with toner particles having opposite polarities.
  • black toner particles having a negative polarity are attracted to the electrostatic latent image corresponding to the black region, i.e. the electrostatic latent image having a positive potential.
  • red toner particles having a positive polarity are attracted to the negative electrostatic latent image, i.e. the electrostatic latent image corresponding to the red region in the original document.
  • the electrostatic jatent image is developed with black and red toner particles.
  • These toner particles have different polarities and are attracted to the respective electrostatic latent images which have polarities opposite therefrom.
  • a two-color toner powder image is formed on the light- sensitive member which corresponds to the color and content of the informational regions contained within the original document.
  • the light-sensitive member With the toner particles adhering thereto, is substantially uniformly illuminated.
  • This illumination inverts the polarity of the electrostatic latent image in the black region.
  • the surface potential of the light-sensitive member in the black region is converted to a negative potential.
  • an A.C. potential superimposed over a D.C. potential having the same polarity as the potential of the black and red portions of the electrostatic latent image is applied to the lights sensitive member.
  • the toner particles are transferred to a copy sheet.
  • the resultant toner powder image transferred to the copy sheet has both red and black regions.
  • This two-color toner powder image is then permanently affixed to the copy sheet by, for example, the application of heat thereto.
  • this two-color toner powder image is charged with a negative D.C. potential. Thereafter, the two-color toner powder image is transferred to the copy sheet and permanently affixed thereto.
  • an A.C. charge is never applied to the two-color toner powder image adhering to the light sensitive member.
  • this latter embodiment is substantially the same as the former embodiment.
  • the method of electrophotographic printing of the present invention forms a two-color copy of a two-color original document in a single pass. In this way, color.. highlighted copies may be readily reproduced from color-highlighted original documents.
  • the printing process heretofore described is a single pass process, the printing machine operates at higher speeds than those heretofore utilized.
  • the electrophotographic printing process of the present invention charges the light-sensitive member, exposes the charged light sensitive member to a cyan-filtered light image, i.e. the complementary color of the color contained within the original document, recharges the light sensitive member, re-exposes the original document through a red filter, i.e. the color corresponding to the color contained within the original document, and develops the resultant electrostatic images with oppositely-charged black and red toner particles.
  • the developed two-color toner powder image adhering to the light...sensitive member is then substantially uniformly illuminated and discharged. Thereafter, the two-color toner powder image is transferred to the copy sheet and permanently affixed thereto resulting in a highlighted color cupy corresponding to the color content of the original document.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Color Electrophotography (AREA)
  • Printing Methods (AREA)
EP82300711A 1981-02-25 1982-02-12 Elektrophotographisches Kopieren Withdrawn EP0060621A3 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP56025388A JPS57139757A (en) 1981-02-25 1981-02-25 Double-color electrophotographing method
JP25387/81 1981-02-25
JP56025387A JPS57139756A (en) 1981-02-25 1981-02-25 Two color electrophotographing system
JP25388/81 1981-02-25

Publications (2)

Publication Number Publication Date
EP0060621A2 true EP0060621A2 (de) 1982-09-22
EP0060621A3 EP0060621A3 (de) 1982-10-27

Family

ID=26362979

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82300711A Withdrawn EP0060621A3 (de) 1981-02-25 1982-02-12 Elektrophotographisches Kopieren

Country Status (1)

Country Link
EP (1) EP0060621A3 (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0077217A1 (de) * 1981-10-13 1983-04-20 Xerox Corporation Mehrschichtige organische lichtempfindliche Vorrichtung
US7968624B2 (en) 2006-10-23 2011-06-28 Lord Corporation Highly filled polymer materials

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3045644A (en) * 1957-06-06 1962-07-24 Xerox Corp Two-color electrostatic printing apparatus
DE2358235A1 (de) * 1972-11-22 1974-05-30 Canon Kk Elektrophotographisches aufzeichnungsverfahren und -geraet
JPS53149033A (en) * 1977-06-01 1978-12-26 Toshiba Corp Zerography
JPS547338A (en) * 1977-06-20 1979-01-20 Ricoh Co Ltd Two-color electrophotographic copying method
JPS5411732A (en) * 1977-06-28 1979-01-29 Ricoh Co Ltd Dichromatic copying method
JPS5462830A (en) * 1977-10-28 1979-05-21 Ricoh Co Ltd Two-color electrophotographic copying method
JPS5515151A (en) * 1978-07-18 1980-02-02 Nec Corp Electrophotographic method
JPS5559473A (en) * 1978-10-26 1980-05-02 Nec Corp Electrophotographic method
JPS5593170A (en) * 1979-01-08 1980-07-15 Ricoh Co Ltd Multicolor electrophotographic copying method

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3045644A (en) * 1957-06-06 1962-07-24 Xerox Corp Two-color electrostatic printing apparatus
DE2358235A1 (de) * 1972-11-22 1974-05-30 Canon Kk Elektrophotographisches aufzeichnungsverfahren und -geraet
JPS53149033A (en) * 1977-06-01 1978-12-26 Toshiba Corp Zerography
JPS547338A (en) * 1977-06-20 1979-01-20 Ricoh Co Ltd Two-color electrophotographic copying method
JPS5411732A (en) * 1977-06-28 1979-01-29 Ricoh Co Ltd Dichromatic copying method
JPS5462830A (en) * 1977-10-28 1979-05-21 Ricoh Co Ltd Two-color electrophotographic copying method
JPS5515151A (en) * 1978-07-18 1980-02-02 Nec Corp Electrophotographic method
JPS5559473A (en) * 1978-10-26 1980-05-02 Nec Corp Electrophotographic method
JPS5593170A (en) * 1979-01-08 1980-07-15 Ricoh Co Ltd Multicolor electrophotographic copying method

Non-Patent Citations (7)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN, Vol. 3, No. 21, 21 February 1979, page 106, E-92; & JP-A-53 149 033 *
PATENT ABSTRACTS OF JAPAN, Vol. 3, No. 28, 9 March 1979, page 145, E-96; & JP-A-54 007 338 *
PATENT ABSTRACTS OF JAPAN, Vol. 3, No. 31, 16 March 1979, page 159, E-98; & JP-A-54 011 732 *
PATENT ABSTRACTS OF JAPAN, Vol. 3, No. 85, 21 July 1979, page 82, E-124; & JP-A-54 062 830 *
PATENT ABSTRACTS OF JAPAN, Vol. 4, No. 100, 18 July 1980, page 142, P-19; & JP-A-55 059 473 *
PATENT ABSTRACTS OF JAPAN, Vol. 4, No. 146, 15 October 1980, page 6, P-31; & JP-A-55 093 170 *
PATENT ABSTRACTS OF JAPAN, Vol. 4, No. 43, 4 April 1980, page 116, P-5; & JP-A-55 015 151 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0077217A1 (de) * 1981-10-13 1983-04-20 Xerox Corporation Mehrschichtige organische lichtempfindliche Vorrichtung
EP0077217B1 (de) * 1981-10-13 1986-04-23 Xerox Corporation Mehrschichtige organische lichtempfindliche Vorrichtung
US7968624B2 (en) 2006-10-23 2011-06-28 Lord Corporation Highly filled polymer materials

Also Published As

Publication number Publication date
EP0060621A3 (de) 1982-10-27

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Inventor name: MIYAGI, TAKASHI