US3734609A - Electrophotographic process and apparatus - Google Patents

Electrophotographic process and apparatus Download PDF

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US3734609A
US3734609A US00133788A US3734609DA US3734609A US 3734609 A US3734609 A US 3734609A US 00133788 A US00133788 A US 00133788A US 3734609D A US3734609D A US 3734609DA US 3734609 A US3734609 A US 3734609A
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photoconductive layer
layer
insulative
photoconductive
conductive base
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US00133788A
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H Tanaka
S Takahashi
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Canon Inc
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Canon Inc
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    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03GELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00Apparatus for electrographic processes using a charge pattern
    • G03G15/22Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20
    • G03G15/226Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 where the image is formed on a dielectric layer covering the photoconductive layer
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03GELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00Apparatus for electrographic processes using a charge pattern
    • G03G15/04Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material
    • G03G15/045Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material with means for charging or discharging distinct portions of the charge pattern on the recording material, e.g. for contrast enhancement or discharging non-image areas
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03GELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00Apparatus for electrographic processes using a charge pattern
    • G03G15/22Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20
    • 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
    • G03G5/04Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/08Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being inorganic
    • G03G5/087Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being inorganic and being incorporated in an organic bonding material

Definitions

  • ABSTRACT A process and apparatus for forming an electrostatic image on a photosensitive plate having a conductive base, a photoconductive layer overlying the base and exhibiting p-type or n-type semiconductivity, and an insulative layer overlying the photoconductive layer.
  • the electrostatic image is formed by first applying a first charge of a polarity opposite to the conductivity type of the photoconductive layer substantially uniformly onto the insulative layer to inject and bind carrier charge in the region of the interface between the insulative and photoconductive layers. Then the photoconductive layer is exposed to a pattern of image light, while a corona discharge of a polarity opposite to that of the first charge is applied onto the insulative layer. Thereafter the photoconductive layer is exposed to activating light to discharge bound carrier charge remaining in the region of the interface and form a high contrast electrostatic image.
  • An object of the present invention is to provide a process and apparatus for producing an electrostatic image in accordance with the electrostatic method of said copending application Ser. No. 563,899, now abandoned, wherein the insulating layer is non-transparent and wherein the conductive base is made of a translucent substance; and to provide a process and apparatus for forming an electrostatic image of the original image on the insulating layer by irradiating the original image from the translucent base side and simultaneously applying corona discharge on the insulating layer.
  • FIGS. 6 and 7 show an embodiment of the electrophotographic device where the present invention is applied.
  • B is a photosensitive plate, comprising an overlaying photoconductive layer 2b and insulating layer 3b.
  • 4b is a transparent support for photosensitive plate B, and on one surface thereof, conductive coating is disposed to form the electrode 41b.
  • the photosensitive plate B is characterized in having carrier charge of a polarity corresponding to the conductivity type of the photoconductive layer 2b injectable from the electrode 41b into the photoconductive layer 2b and bound in the region of the interface between the insulating layer 3b and photoconductive layer 2b.
  • the photoconductive layer 2b can be prepared using conventional semiconductor materials which have photoconductivity, such as Se, ZnO, CdS and the like, dispersed in a dispersing agent, and coated on the conductive base by means of coating or vacuum evaporation, sublimation, melting or the like.
  • the insulating layer 3b used depends on the spectral sensitivity of the photoconductive material forming the photoconductive layer 2b.
  • Mylar a polyester terephthalate film manufactured by DuPont
  • a filter is provided.
  • Photosensitive plate B is overlaid on support 4b, and a primary charge is made by charging device 5b from the side of insulating layer 3b (either corona discharge or the electrode contact method can be employed).
  • the photoconductive layer 2b is an n-type semiconductor, that it be positive; and where it is a ptype semiconductor, that it be negative.
  • the residual charge of the prior electrostatic latent image is erased by the primary charge, and at the same time the contrast of the electrostatic latent image is greatly improved.
  • the image is visualized on the surface of the insulating layer, and the resulting image is transferred onto the transferring material 8b, and the photosensitive plate B is cleaned, and reused.
  • the image transferred onto the transferring material 8b is fixed and used as an ordinary copy (FIG. 5).
  • 9b is the developer
  • 10b (FIGS. 1 and 2) is the means for generating high voltage
  • 10b is connected to the corona generating coil W (FIGS. 1 and 2), while high voltage E is applied to the side of transparent electrode 4b.
  • FIGS. 6 and 7 show an embodiment of an electrophotographic device wherein the present invention is employed.
  • the image of the original copy 12b placed on the glass 11b is illuminated by the lamp 13b, and projected onto the photosensitive plate B as a positive image by means of the reflecting optical system 18b which contains the reflecting mirrors 14b, 15b, 16b and lens 17b.
  • the reflecting optical system 18b is moved to the right and left at a constant speed by the reversible motor M, and chain 20b along the rail 19b, and projects the whole length of the image of the original copy 12b on the photosensitive plate B in turn.
  • Lamp 21b provides overall exposure at the reflecting optical system 18b.
  • Charger 23b comprises corona discharging portions 23ab and 23bb for primary and secondary charges, and is made so as to move to the right and left on the two rails 22b provided on the frame 26b parallel with the photosensitive plate B.
  • Magnet 24b is provided on charger 23b, and the attraction of the magnet 25b attached to the reflecting optical system 18b to magnet 24b, moves charger 23b in the same direction as the optical system 18b, in accordance with the movement of the optical system 18b.
  • An electrostatic latent image is formed on the photosensitive plate B similar to the image of the original copy 12b by means of a single scanning of the reflecting optical system 18b in the direction as shown by an arrow in FIG. 6.
  • the respective operations of developing the image, transferring the developed image, and cleaning are done elsewhere.
  • the insulating layer of the photosensitive plate obtained by overlaying the insulating layer on the surface of photoconductive layer is made sufficiently opaque so as to not allow any light to penetrate which is within the photosensitive wave length region of photoconductive layer, and therefore the whole process of making an image can be done in a lighted area.
  • An apparatus for forming an electrostatic image comprising:
  • a photosensitive plate having a conductive base, a
  • photoconductive layer overlying said base and exhibiting p-type or n-type semiconductivity and an insulative layer overlying said photoconductive layer, said conductive base being transparent to activating light for said photoconductive layer and said insulative layer being opaque to said activating light, said photosensitive plate being characterized in having carrier charge of a polarity corresponding to the conductivity type of said photoconductive layer injectable from said conductive base into said photoconductive layer and bound in the region of the interface between said insulative and photoconductive layers,
  • charging means for applying a first charge of a polarity opposite to the conductivity type of said photoconductive layer substantially uniformly onto said insulative layer to inject and bind carrier charge in the region of the interface between said insulative and photoconductive layers
  • means (c) includes means for applying a corona discharge of a polarity opposite to that of said first charge onto said insulative layer.
  • cleaning means for removing from said photosensitive late residual developer remaining after the transfer of the visualized image whereby said photosensitive plate is prepared for repeated use.

Abstract

A process and apparatus for forming an electrostatic image on a photosensitive plate having a conductive base, a photoconductive layer overlying the base and exhibiting p-type or n-type semiconductivity, and an insulative layer overlying the photoconductive layer. The photosensitive plate is characterized in having carrier charge of a polarity corresponding to the conductivity type of the photoconductive layer injectable from the conductive base into the photoconductive layer and bound in the region of the interface between the insulative and photoconductive layers. The conductive base is transparent to activating light and the insulative layer is opaque to the activating light. A first charge of a polarity opposite to the conductivity type of the photoconductive layer is applied onto the insulative layer to inject and bind carrier charge in the region of the interface between the insulative and photoconductive layers. Then, the photoconductive layer is exposed to a pattern of activating image light by projecting the image light through the transparent conductive base while a corona discharge is applied onto the insulative layer. Thereafter, the photoconductive layer is exposed to activating light through the transparent conductive base to discharge bound carrier charge remaining in the region of the interface and form a high contrast electrostatic image.

Description

United States Patent [191 Tanaka et a1.
[ 3,734,609 [451 May 22,1973
[54] ELECTROPHOTOGRAPHIC PROCESS AND APPARATUS [75] Inventors: Hiroshi Tanaka, Tokyo; Shinkichi Takahashi, Kanagawa, both of Japan [73] Assignee: Canon Kabushiki Kaisha, Tokyo,
Japan [22] Filed: Apr. 14, 1971 [21] Appl. No.: 133,788
Related U.S. Application Data [62] Division of Ser. No. 563,899, July 8, 1966, abandoned.
[58] Field of Search ..355/16, 17,11, 8, 355/3; 96/1 R, 1 C, 1.4
[56] References Cited UNITED STATES PATENTS 3,536,483 10/1970 Watanabe et al ..355/3 X Primary ExaminerRichard L. Moses AttorneyWard, McElhannon, Brooks & Fitzpatrick [57] ABSTRACT A process and apparatus for forming an electrostatic image on a photosensitive plate having a conductive base, a photoconductive layer overlying the base and exhibiting p-type or n-type semiconductivity, and an insulative layer overlying the photoconductive layer. The photosensitive plate is characterized in having carrier charge of a polarity corresponding to the conductivity type of the photoconductive layer injectable from the conductive base into the photoconductive layer and bound in the region of the interface between the insulative and photoconductive layers. The conductive base is transparent to activating light and the insulative layer is opaque to the activating light. A first charge of a polarity opposite to the conductivity type of the photoconductive layer is applied onto the insulative layer to inject and bind carrier charge in the region of the interface between the insulative and photoconductive layers. Then, the photoconductive layer is exposed to a pattern of activating image light by projecting the image light through the transparent conductive base while a corona discharge is applied onto the insulative layer. Thereafter, the photoconductive layer is exposed to activating light through the transparent conductive base to discharge bound carrier charge remaining in the region of the interface and form a high contrast electrostatic image.
3 Claims, 7 Drawing Figures PATENTEWYEZIW 3,734,609
SHEET 2 0F 2 IN VENTORS Meosa/ 751mm SH/Wk/CH/ MHASW/ 1 ELECTROPHOTOGRAPHIC PROCESS AND APPARATUS This is a division of U. S. Pat. application Ser. No. 563,899, now abandoned, filed July 8, 1966.
This invention relates to an electrographic process and apparatus, and more particularly to process and apparatus for forming electrostatic images.
In copending and commonly assigned U. S. Pat. application Ser. No. 563,899, now abandoned, filed July 8, 1966, an electrostatic image is formed on a photosensitive plate having a conductive base, a photoconductive layer overlying the base and exhibiting p-type or n-type semiconductivity and an insulative layer overlying the photoconductive layer. The photosensitive plate is characterized in having carrier charge of a polarity corresponding to the conductivity type of the photoconductive layer injectable from the conductive base into the photoconductive layer and bound in the region of the interface between the insulative and photoconductive layers. The electrostatic image is formed by first applying a first charge of a polarity opposite to the conductivity type of the photoconductive layer substantially uniformly onto the insulative layer to inject and bind carrier charge in the region of the interface between the insulative and photoconductive layers. Then the photoconductive layer is exposed to a pattern of image light, while a corona discharge of a polarity opposite to that of the first charge is applied onto the insulative layer. Thereafter the photoconductive layer is exposed to activating light to discharge bound carrier charge remaining in the region of the interface and form a high contrast electrostatic image.
An object of the present invention is to provide a process and apparatus for producing an electrostatic image in accordance with the electrostatic method of said copending application Ser. No. 563,899, now abandoned, wherein the insulating layer is non-transparent and wherein the conductive base is made of a translucent substance; and to provide a process and apparatus for forming an electrostatic image of the original image on the insulating layer by irradiating the original image from the translucent base side and simultaneously applying corona discharge on the insulating layer.
The above object and various other objects and the advantages of the present invention will become clear from the following detailed description, taken in conjunction with the accompanying drawings, in which:
FIGS. 1 to schematically show the stages of making electrostatic images according to the present invention; and
FIGS. 6 and 7 show an embodiment of the electrophotographic device where the present invention is applied.
In FIG. 1, B is a photosensitive plate, comprising an overlaying photoconductive layer 2b and insulating layer 3b. 4b is a transparent support for photosensitive plate B, and on one surface thereof, conductive coating is disposed to form the electrode 41b.
The photosensitive plate B is characterized in having carrier charge of a polarity corresponding to the conductivity type of the photoconductive layer 2b injectable from the electrode 41b into the photoconductive layer 2b and bound in the region of the interface between the insulating layer 3b and photoconductive layer 2b.
. The photoconductive layer 2b can be prepared using conventional semiconductor materials which have photoconductivity, such as Se, ZnO, CdS and the like, dispersed in a dispersing agent, and coated on the conductive base by means of coating or vacuum evaporation, sublimation, melting or the like.
The insulating layer 3b used depends on the spectral sensitivity of the photoconductive material forming the photoconductive layer 2b. For example, where the photoconductive layer has a sensitivity to visible rays, Mylar (a polyester terephthalate film manufactured by DuPont) colored black is used or a filter is provided.
The process for making the image is explained hereinafter in accordance with FIG. 1 through FIG. 5. Photosensitive plate B is overlaid on support 4b, and a primary charge is made by charging device 5b from the side of insulating layer 3b (either corona discharge or the electrode contact method can be employed). I
As to the charge polarity in this case, it is preferable that where the photoconductive layer 2b is an n-type semiconductor, that it be positive; and where it is a ptype semiconductor, that it be negative. The residual charge of the prior electrostatic latent image, is erased by the primary charge, and at the same time the contrast of the electrostatic latent image is greatly improved.
Then, as shown in FIG. 2, a secondary charge of opposite polarity to the primary charge is made while projecting the original copy 6b from the side of the photoconductive layer 2b of the photosensitive plate B, and thereafter overall radiation is made with lamp 7b to form the electrostatic latent image on the insulating layer 3b (FIG. 3).
Thereafter, in accordance with conventional methods, the image is visualized on the surface of the insulating layer, and the resulting image is transferred onto the transferring material 8b, and the photosensitive plate B is cleaned, and reused. The image transferred onto the transferring material 8b is fixed and used as an ordinary copy (FIG. 5). 9b is the developer, and 10b (FIGS. 1 and 2) is the means for generating high voltage, and 10b is connected to the corona generating coil W (FIGS. 1 and 2), while high voltage E is applied to the side of transparent electrode 4b.
FIGS. 6 and 7 show an embodiment of an electrophotographic device wherein the present invention is employed. The image of the original copy 12b placed on the glass 11b is illuminated by the lamp 13b, and projected onto the photosensitive plate B as a positive image by means of the reflecting optical system 18b which contains the reflecting mirrors 14b, 15b, 16b and lens 17b. The reflecting optical system 18b is moved to the right and left at a constant speed by the reversible motor M, and chain 20b along the rail 19b, and projects the whole length of the image of the original copy 12b on the photosensitive plate B in turn. Lamp 21b provides overall exposure at the reflecting optical system 18b.
Charger 23b comprises corona discharging portions 23ab and 23bb for primary and secondary charges, and is made so as to move to the right and left on the two rails 22b provided on the frame 26b parallel with the photosensitive plate B. Magnet 24b is provided on charger 23b, and the attraction of the magnet 25b attached to the reflecting optical system 18b to magnet 24b, moves charger 23b in the same direction as the optical system 18b, in accordance with the movement of the optical system 18b.
An electrostatic latent image is formed on the photosensitive plate B similar to the image of the original copy 12b by means of a single scanning of the reflecting optical system 18b in the direction as shown by an arrow in FIG. 6. The respective operations of developing the image, transferring the developed image, and cleaning are done elsewhere.
In accordance with the present invention, the insulating layer of the photosensitive plate obtained by overlaying the insulating layer on the surface of photoconductive layer, as mentioned above, is made sufficiently opaque so as to not allow any light to penetrate which is within the photosensitive wave length region of photoconductive layer, and therefore the whole process of making an image can be done in a lighted area.
It is apparent that the present invention can be modified by the expert in the art within the scope of the disclosure herein and the following claims.
What is claimed is:
1. An apparatus for forming an electrostatic image comprising:
a. a photosensitive plate having a conductive base, a
photoconductive layer overlying said base and exhibiting p-type or n-type semiconductivity and an insulative layer overlying said photoconductive layer, said conductive base being transparent to activating light for said photoconductive layer and said insulative layer being opaque to said activating light, said photosensitive plate being characterized in having carrier charge of a polarity corresponding to the conductivity type of said photoconductive layer injectable from said conductive base into said photoconductive layer and bound in the region of the interface between said insulative and photoconductive layers,
b. charging means for applying a first charge of a polarity opposite to the conductivity type of said photoconductive layer substantially uniformly onto said insulative layer to inject and bind carrier charge in the region of the interface between said insulative and photoconductive layers,
' c. means for exposing said photoconductive layer to a pattern of activating image light while applying a corona discharge onto said insulative layer, said means for exposing said photoconductive layer to image light comprising means for projecting said image light through said transparent conductive base, and
(1. means for thereafter projecting activating light through said transparent conductive base to discharge bound carrier charge remaining in the region of said interface and form a high contrast electrostatic image.
2. An apparatus according to claim 1, wherein means (c) includes means for applying a corona discharge of a polarity opposite to that of said first charge onto said insulative layer.
3. An apparatus according to claim 1, further comprising:
e. developing means for visualizing said electrostatic image,
f. means for transferring said visualized image onto copy material, and
g. cleaning means for removing from said photosensitive late residual developer remaining after the transfer of the visualized image whereby said photosensitive plate is prepared for repeated use.

Claims (3)

1. An apparatus for forming an electrostatic image comprising: a. a photosensitive plate having a conductive base, a photoconductive layer overlying said base and exhibiting p-type or n-type semiconductivity and an insulative layer overlying said photoconductive layer, said conductive base being transparent to activating light for said photoconductive layer and said insulative layer being opaque to said activating light, said photosensitive plate being characterized in having carrier charge of a polarity corresponding to the conductivity type of said photoconductive layer injectable from said conductive base into said photoconductive layer and bound in the region of the interface between said insulative and photoconductive layers, b. charging means for applying a first charge of a polarity opposite to the conductivity type of said photoconductive layer substantially uniformly onto said insulative layer to inject and bind carrier charge in the region of the interface between said insulative and photoconductive layers, c. means for exposing said photoconductive layer to a pattern of activating image light while applying a corona discharge onto said insulative layer, said means for exposing said photoconductive layer to image light comprising means for projecting said image light through said transparent conductive base, and d. means for thereafter projecting activating light through said transparent conductive base to discharge bound carrier charge remaining in the region of said interface and form a high contrast electrostatic image.
2. An apparatus according to claim 1, wherein means (c) includes means for applying a corona discharge of a polarity opposite to that of said first charge onto said insulative layer.
3. An apparatus according to claim 1, further comprising: e. developing means for visualizing said electrostatic image, f. means for transferring said visualized image onto copy material, and g. cleaning means for removing from said photosensitive late residual developer remaining after the Transfer of the visualized image whereby said photosensitive plate is prepared for repeated use.
US00133788A 1966-02-23 1971-04-14 Electrophotographic process and apparatus Expired - Lifetime US3734609A (en)

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2715730A1 (en) * 1976-04-13 1977-11-03 Canon Kk METHOD AND DEVICE FOR AVOIDING IMPAIRMENT OF AN UNFIXED VISIBLE IMAGE
US4358520A (en) * 1976-09-17 1982-11-09 Canon Kabushiki Kaisha Method of stabilizing an electrostatic latent image
US4445126A (en) * 1981-01-12 1984-04-24 Canon Kabushiki Kaisha Image forming apparatus
US4621919A (en) * 1983-07-13 1986-11-11 Canon Kabushiki Kaisha Metal drum and image holding member using the same
US5382487A (en) * 1979-12-13 1995-01-17 Canon Kabushiki Kaisha Electrophotographic image forming member
US20100302341A1 (en) * 2009-05-28 2010-12-02 Xerox Corporation Two-dimensional ros emitter geometry with low banding sensitivity

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Publication number Priority date Publication date Assignee Title
US4649094A (en) * 1981-12-08 1987-03-10 Canon Kabushiki Kaisha Image formation method and apparatus in which imaging light and conductive toner are applied to opposite surfaces of a photosensitive member
JPS59228256A (en) * 1983-06-09 1984-12-21 Canon Inc Display device
US5008707A (en) * 1989-09-05 1991-04-16 Xerox Corporation Simultaneous charging and exposure for pictorial quality
US5132627A (en) * 1990-12-28 1992-07-21 Xerox Corporation Motionless scanner
JP2002351160A (en) * 2001-05-22 2002-12-04 Toshiba Tec Corp Image forming device

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US3536483A (en) * 1964-10-20 1970-10-27 Katsuragawa Denki Kk Method of making electrographs wherein the resultant electrostatic image is not effected by further light exposure

Family Cites Families (4)

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Publication number Priority date Publication date Assignee Title
US3182573A (en) * 1961-08-11 1965-05-11 Xerox Corp Masked plate xerography
US3272626A (en) * 1962-02-23 1966-09-13 Royal Typewriter Co Inc Xerographic method
US3457070A (en) * 1964-07-25 1969-07-22 Matsuragawa Electric Co Ltd Electrophotography
US4071361A (en) * 1965-01-09 1978-01-31 Canon Kabushiki Kaisha Electrophotographic process and apparatus

Patent Citations (1)

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Publication number Priority date Publication date Assignee Title
US3536483A (en) * 1964-10-20 1970-10-27 Katsuragawa Denki Kk Method of making electrographs wherein the resultant electrostatic image is not effected by further light exposure

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2715730A1 (en) * 1976-04-13 1977-11-03 Canon Kk METHOD AND DEVICE FOR AVOIDING IMPAIRMENT OF AN UNFIXED VISIBLE IMAGE
US4358520A (en) * 1976-09-17 1982-11-09 Canon Kabushiki Kaisha Method of stabilizing an electrostatic latent image
US5382487A (en) * 1979-12-13 1995-01-17 Canon Kabushiki Kaisha Electrophotographic image forming member
US4445126A (en) * 1981-01-12 1984-04-24 Canon Kabushiki Kaisha Image forming apparatus
US4621919A (en) * 1983-07-13 1986-11-11 Canon Kabushiki Kaisha Metal drum and image holding member using the same
US20100302341A1 (en) * 2009-05-28 2010-12-02 Xerox Corporation Two-dimensional ros emitter geometry with low banding sensitivity
US8115795B2 (en) 2009-05-28 2012-02-14 Xerox Corporation Two-dimensional ROS emitter geometry with low banding sensitivity

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