US3692519A - Electrophotographic color process - Google Patents

Electrophotographic color process Download PDF

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Publication number
US3692519A
US3692519A US841256A US3692519DA US3692519A US 3692519 A US3692519 A US 3692519A US 841256 A US841256 A US 841256A US 3692519D A US3692519D A US 3692519DA US 3692519 A US3692519 A US 3692519A
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US
United States
Prior art keywords
image
color
photosensitive member
original
charge
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
US841256A
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English (en)
Inventor
Toru Takahashi
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.)
Canon Inc
Original Assignee
Canon Inc
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 Canon Inc filed Critical Canon Inc
Application granted granted Critical
Publication of US3692519A publication Critical patent/US3692519A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/12—Recording members for multicolour processes
    • 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
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/14—Inert intermediate or cover layers for charge-receiving layers
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/14—Inert intermediate or cover layers for charge-receiving layers
    • G03G5/147—Cover layers
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/14—Inert intermediate or cover layers for charge-receiving layers
    • G03G5/147—Cover layers
    • G03G5/14704—Cover layers comprising inorganic material
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S430/00—Radiation imagery chemistry: process, composition, or product thereof
    • Y10S430/001—Electric or magnetic imagery, e.g., xerography, electrography, magnetography, etc. Process, composition, or product
    • Y10S430/102—Electrically charging radiation-conductive surface

Definitions

  • FIG. 3K2 Sept- 19, 1972 ToRu TAKAHASHI 3,692,519
  • the general technique hitherto employed in electrophotography for reproducing multi-colored originals is to uniformly charge a photosensitive body having a photoconductive layer, then form a latent image corresponding to the black letters by projecting an optical image through a red lter, then develop said latent image with black toner, and then transfer the developed image to paper, etc.
  • the photosenstive plate is cleaned and recharged, and a latent image corresponding to both the red frames and black letters is formed by projecting an irradiating optical image through a cyan lilter which blocks red.
  • the latent image thus formed is developed with red toner and the developed image is superimposed on said paper, etc.
  • the black letters are liable to be illegible and dirty if there is lack of color registration caused by inaccurate superposition of the red toner image on the black toner image.
  • Complete avoidance of such displacement is hard to obtain because it depends upon position matching at time of transfer and requires high mechanical precision.
  • red toner is placed on black letters, color reproduction lacks delity.
  • Color control is dependent upon extremely complex factors when the known process is applied to natural color photographs. For example, since a thick red toner image is superimposed on a thick black image in reproducing a dark red image, only a red or black image is obtained if the toner placed on top is opaque. This is especially true in cases of business documents composed largely of black letters. When a document composed mainly of black letters contains a natural color photograph, the user must bear the inconvenience of color shift in the black letters caused by the presence of the natural color photograph. Moreover, this method has the defect of being unable to reproduce just a given color from a multi-colored original.
  • This invention olers a novel electrophotographic proc- ICC ess capable of eliminating the above-mentioned inconveniences, and it is characterized by converting the difference between the light intensity of a desired color to be copied and the light intensities of the remaining colors into difference in copying density by using filters, etc., and by converting the difference between the intensity of a spectral wavelength region A of an image of the original and the intensity of a spectral wavelength region B into the difference in image density.
  • an object of this invention is to obtain a reproduction of a portion of a multi-colored original having a specified or discrete color in a simple manner as compared with conventional techniques.
  • Another object of this invention is to obtain a multicolored reproduction, not olf-color and with fidelity to the original, from a multi-colored original by repeating said single color copying process a desired number of times.
  • a still further object of this invention is to provide means for practicing the invention.
  • FIGS. 1(A), (B), and (C) are explanatory diagrams of the electrophotographic process as practiced according to the invention.
  • FIG. 2 is a diagram showing steps in the production of a copy according to said process
  • FIGS. 3 and 4, (A), (B), (C), are explanatory diagrams for other embodiments of the invented electrophotographic process as practiced.
  • FIGS. 5 through 7 are side views of three embodiments of the discharger used in practicing this invention.
  • 1 is a multi-colored original
  • 2 is a colored image on the multi-colored original 1, having a color, for example, red, to be copied
  • 3 is another image having a color other than red, for example, black
  • 4 is a lter that passes the color of image 2, in this example a red filter, placed between the multi-colored original 1 Iand a photosensitive member p
  • 5 is also a lter which blocks the color of image 2 but passes other colors
  • 6 is a corona dischargei for primary charging
  • 7 is a discharger which performs either AC discharge or secondary charging opposite in polarity to the primary charging
  • p is the photosensitive member comprising a transparent insulating (insulative) layer 8, photoconductive layer 9, and base plate 10
  • the surface of the insulating layer 8 of photosensitive member p is primary charged positively by the discharger 6 which is optically transparent either with the upper part of shield
  • the reflected light from the image 2, which in this example is red also reaches the photosensitive member p after passing through the filter 4, and a negative charge is induced on the back surface of the insulating layer 8 similar to that in the regions a.
  • the resistance of the photoconductive layer 9 is not decreased and negative charge is not induced on the back surface of the insulating layer 8.
  • negative charge i.e. opposite in polarity to the primary charge, is induced on the back surface of the insulating layer 8 of the photosensitive member p in the regions a and b but not the region c.
  • projection of the optical image can be accomplished by using light of a single wave-length having the color desired for reproduction instead of using a iilter.
  • Another photosensitive member was prepared by melting at about 500 C. for about three hours, a mixture of Se Te 10% and a small amount of Ge (0.004- 0.5 then heating it at about 250-350 C. in a vacuum (below 10-4l mm. Hg) and evaporating it on an aluminum base plate held at 58 C. to a thickness of about 50p., to which a polyester film, 25a in thickness was secured by an epoxy adhesive.
  • the surface of the aluminum base plate was oxidized before the evaporation step. In either case, excellent results were obtained.
  • a photosensitive member comprising the abovementioned three layers but with the base plate 10 consisting of an insulating layer.
  • this photosensitive member it is sufficient to place the photosensitive member on an electrically conductive holding plate or to apply voltages, opposite in polarity, to both surfaces of the photosensitive body during charging or discharging according to the above-mentioned process.
  • the insulating layers in the photosensitive member used in this invention are composed of insulating substances having charge holding properties, and can be selected from among organic and inorganic insulating materials.
  • the electrically conductive layer metallic materials, paper and other electrostatically conductive materials can be employed.
  • the composite toner image formed on the transfer medium is Ifixed to the above-mentioned transmedium by any suitable method, for example, by heatfixing. In this way a color copy is produced from four superimposed colored images.
  • the corresponding dark red color can be reproduced by superimposing a thin red toner image upon a thin black toner image without using a semi-transparent toner.
  • said base plate comprises an insnlative member and an electrically conductive member underlying said insulative member.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Photoreceptors In Electrophotography (AREA)
  • Electrophotography Using Other Than Carlson'S Method (AREA)
  • Color Electrophotography (AREA)
US841256A 1968-07-23 1969-07-14 Electrophotographic color process Expired - Lifetime US3692519A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP43052077A JPS4834770B1 (de) 1968-07-23 1968-07-23

Publications (1)

Publication Number Publication Date
US3692519A true US3692519A (en) 1972-09-19

Family

ID=12904738

Family Applications (1)

Application Number Title Priority Date Filing Date
US841256A Expired - Lifetime US3692519A (en) 1968-07-23 1969-07-14 Electrophotographic color process

Country Status (4)

Country Link
US (1) US3692519A (de)
JP (1) JPS4834770B1 (de)
DE (1) DE1937488C3 (de)
GB (1) GB1282018A (de)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3884686A (en) * 1971-12-28 1975-05-20 Xerox Corp Color correction method
US4045219A (en) * 1976-01-07 1977-08-30 Xerox Corporation Method of reproducing color highlighted documents
US4281051A (en) * 1978-11-29 1981-07-28 Ricoh Company, Ltd. Three color electrostatographic process
US4335194A (en) * 1978-02-20 1982-06-15 Ricoh Company, Ltd. Two color electrophotographic process and material
US4346159A (en) * 1977-02-14 1982-08-24 Fuji Xerox Co., Ltd. Photosensitive element for electrophotography
US4349268A (en) * 1979-06-28 1982-09-14 Konishiroku Photo Industry Co., Ltd. Electrostatic image-forming process and an apparatus therefor
US4378415A (en) * 1981-10-13 1983-03-29 Xerox Corporation Color imaging, layered organic photoresponsive device having hole injection and transport layers, red sensitive layer and short wavelength sensitive layer
FR2517439A1 (fr) * 1981-11-27 1983-06-03 Ishihara Mining & Chemical Co Procede electrophotographique
US4407917A (en) * 1978-08-28 1983-10-04 Ricoh Company, Ltd. Information image synthesizing and copying method
EP0148549A2 (de) * 1983-12-23 1985-07-17 Mark I Marketing Corporation Farbreproduktionsverfahren
EP0195564A2 (de) * 1985-03-18 1986-09-24 Mark I Marketing Corporation Farbreproduktionsverfahren

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4413899A (en) * 1980-01-30 1983-11-08 Ricoh Company, Ltd. Copying method and apparatus
JPS6170564A (ja) * 1984-09-14 1986-04-11 Toshiba Corp 画像形成装置

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3884686A (en) * 1971-12-28 1975-05-20 Xerox Corp Color correction method
US4045219A (en) * 1976-01-07 1977-08-30 Xerox Corporation Method of reproducing color highlighted documents
US4346159A (en) * 1977-02-14 1982-08-24 Fuji Xerox Co., Ltd. Photosensitive element for electrophotography
US4335194A (en) * 1978-02-20 1982-06-15 Ricoh Company, Ltd. Two color electrophotographic process and material
US4407917A (en) * 1978-08-28 1983-10-04 Ricoh Company, Ltd. Information image synthesizing and copying method
US4281051A (en) * 1978-11-29 1981-07-28 Ricoh Company, Ltd. Three color electrostatographic process
US4349268A (en) * 1979-06-28 1982-09-14 Konishiroku Photo Industry Co., Ltd. Electrostatic image-forming process and an apparatus therefor
US4378415A (en) * 1981-10-13 1983-03-29 Xerox Corporation Color imaging, layered organic photoresponsive device having hole injection and transport layers, red sensitive layer and short wavelength sensitive layer
FR2517439A1 (fr) * 1981-11-27 1983-06-03 Ishihara Mining & Chemical Co Procede electrophotographique
EP0148549A2 (de) * 1983-12-23 1985-07-17 Mark I Marketing Corporation Farbreproduktionsverfahren
EP0148549A3 (en) * 1983-12-23 1987-02-25 Wallace Edwards Improved colour reproduction process
EP0195564A2 (de) * 1985-03-18 1986-09-24 Mark I Marketing Corporation Farbreproduktionsverfahren
EP0195564A3 (en) * 1985-03-18 1987-02-04 Wallace Edwards Improved color reproduction process

Also Published As

Publication number Publication date
GB1282018A (en) 1972-07-19
DE1937488C3 (de) 1975-03-27
DE1937488B2 (de) 1974-08-08
JPS4834770B1 (de) 1973-10-23
DE1937488A1 (de) 1970-06-04

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