US3770429A - Method for removing corona discharge contaminants in electrophotography - Google Patents

Method for removing corona discharge contaminants in electrophotography Download PDF

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Publication number
US3770429A
US3770429A US00179805A US3770429DA US3770429A US 3770429 A US3770429 A US 3770429A US 00179805 A US00179805 A US 00179805A US 3770429D A US3770429D A US 3770429DA US 3770429 A US3770429 A US 3770429A
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United States
Prior art keywords
highly insulative
image forming
insulative layer
forming surface
latent image
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Expired - Lifetime
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US00179805A
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English (en)
Inventor
K Kinoshita
S Uehara
H Nagame
K Yamada
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Katsuragawa Electric Co Ltd
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Katsuragawa Electric Co Ltd
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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
    • G03G5/005—Materials for treating the recording members, e.g. for cleaning, reactivating, polishing
    • 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
    • G03G21/00—Arrangements not provided for by groups G03G13/00 - G03G19/00, e.g. cleaning, elimination of residual charge

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  • ABSTRACT In a method and apparatus for electrophotography in which use is made of photosensitive element including a photoconductive layer and an image forming surface which may be the surface of the photoconductive layer or the surface of a highly insulative layer integrally bonded to the surface of the photoconductive layer and wherein an electric charge is deposited on the image forming surface by means of corona discharge, a light image is projected upon the photosensitive element to form a latent image on the image forming surface, and the latent image is transfer printed onto a recording medium, means is provided to apply an organic solvent to the image forming surface to remove contaminants formed by the ionization of air by the corona discharge.
  • Photosensitive elements presently used in the art of electrophotography can be classified into two types, one comprising a photoconductive layer and the other comprising a highly insulative layer and a photoconductive layer integrally bonded to the highly insulative layer.
  • Latent images are formed on the surface of the photoconductive layer or of the highly insulative layer depending upon the method of forming the latent image. While a number of methods have been proposed to deposit an electric charge of given polarity on the image forming surface of the photosensitive element, the method which uses corona discharge is most suitable because it is not necessary to use an electrode in contact with the image forming surface and because it is possible to apply electric fields of high potential.
  • a latent image is formed by the steps of applying a first electric field across a photosensitive element including a transparent highly insulative layer, a photoconductive layer exhibiting persistent internal polarization, and an electrode layer which are laminated in the order mentioned and are bonded together into an integral structure whereby to deposit a charge of one polarity on the surface of the highly insulative layer; applying a second electric field across the photosensitive element to deposit a charge of the opposite polarity and projecting a light image upon the photoconductive layer concurrently with the application of the second field whereby to form an electrostatic latent image corresponding to the light image on the surface of the highly insulative layer.
  • the latent image is then developed under ambient light and transfer printed onto a recording medium.
  • the latent image is often transferred onto an insulative film without developing.
  • the photosensitive element can be used repeatedly many times.
  • One problem encountered in the repeated use of the photosensitive element is hysteresis which is caused by charge remaining in the photoconductive layer. This problem has been solved.
  • the contaminants formed by the corona discharge are nitric acid and another acidic substances. More particularly, through the action of the corona discharge, the air near the discharge electrode is ionized to form N This gas and CO gas are conveyed to the image forming surface of the photosensitive element and react with moisture to form such acids as H CO and HNO Unstable acids such as H CO undergo decomposition and disappear in the form of CO, gas which does not cause any problem. On the other hand, HNO, gradually accumulates to form a strongly acidic film and to fix the moisture in the atmosphere on the image forming surface of the photosensitive element.
  • the highly insulative layer of the photosensitive element is coated with such an acidic contaminant, its electrical resistance decreases which lowers its ability to preserve the latent image. As a result, the visible image produced by developing the latent image is not clear and in an extreme case it becomes impossible to produce the picture image.
  • the contaminants are also transferred.
  • the surface of the photosensitive element is not perfectly flat but contains irregularities as described above, certain amounts of the contaminants remain in the defects and cause ion concentra-tion during subsequent use of the photosensitive element.
  • the highly insulative layer of the photosensitive element is generally made of a thin film of synthetic material, typically a polyester resin.
  • a film of polyester resin has sufficiently high electrical and mechanical strength and it has been believed that these properties are extremely stable. However, it was found that, for the reasons described above, these properties degrade relatively rapidly, especially in an atmosphere of high humidity.
  • a latent image is formed on the image forming surface of a photosensitive element including a photoconductive layer by depositing an electric charge on the image forming surface by means of corona discharge and projecting a light image upon the photoconductive layer, and the latent image is transfer printed onto a recording medium
  • an organic solvent is applied onto the image forming surface after the latent image has been transfer printed to remove contaminants formed by the ionization of air by the corona discharge and deposited on the image forming surface.
  • a method of electrophotography of the type wherein a latent image is formed by the steps of applying a first electric field by means of corona discharge across a photosensitive element including a highly insulative layer and a photoconductive layer exhibiting persistent internal polarization and integrally bonded to the highly insulative layer so as to deposit a charge of one polarity on the surface of the highly insulative layer, applying a second electric field by means of corona discharge across the photosensitive element to deposit a charge of the opposite polarity on the surface of the highly insulative layer, and projecting a light image onto the photoconductive layer concurrently with the application of the second electric field thus forming a latent image corresponding to the light image on the surface of the highly insulative layer, and transfer printing said latent image onto a recording medium, characterized in that an organic solvent is applied onto the image forming surface of the highly insulative layer after the latent image has been transfer printed to remove contaminants formed by the ionization of air by the cor
  • apparatus for electrophotography of the type comprising a photosensitive element including a highly insulative layer and a photoconductive layer exhibiting persistent internal polarization and integrally bonded to said highly insulative layer, a rotary drum for supporting the photosensitive element with the highly insulative layer facing outwardly, a first corona discharge unit adapted to deposit a charge of one polarity on the surface of the highly insulative layer, a second corona discharge unit adapted to deposit a charge of the opposite polarity on the surface of the highly insulative layer, an optical system for projecting a light image onto the photoconductive layer concurrently with the operation of the second corona discharge unit whereby to form a latent image corresponding to the light image on the surface of the highly insulative layer, and means for transfer printing the latent image onto a recording medium, there is provided means for applying an organic solvent onto the image forming surface of' the highly insulative layer after the latent image has been transfer printed to remove contaminants formed by the ion
  • the photosensitive element shown in FIG. 1 comprises a highly insulative layer 1 having a thickness of 9 microns and made of a polyester resin sold under the trade name of Mylar, a photoconductive layer 2 exhibiting persistent internal polarization and an electrode layer 3 of thin aluminum foil.
  • a highly insulative layer 1 having a thickness of 9 microns and made of a polyester resin sold under the trade name of Mylar
  • a photoconductive layer 2 exhibiting persistent internal polarization
  • an electrode layer 3 of thin aluminum foil Any organic or inorganic photoconductive material manifesting persistent internal polarization can be used to form the photoconductive layer but in this example the layer 2 was prepared by uniformly dispersing a fine powder of CdS in a polyvinyl acetate binder. Layers 2 and 3 were bonded together into an integral structure and the photo-sensitive element was mounted on a rotary drum with the highly insulative layer facing outwardly.
  • the photosensitive element is of the well known construction and is especially suitable for use in the method of electrophotography wherein first and second electric fields of opposite polarities are applied consecutively across the photosensitive element and an information containing light image is projected upon the photoconductive layer concurrently with the application of the secondfield so as to form a latent image on the surface of the highly insulative layer.
  • the photosensitive element was mounted on a rotary drum 4 with the highly insulative layer 1 facing outwardly.
  • the electrode layer 3 may be omitted as in FIG. 2.
  • the drum was rotated in the clockwise direction as shown by the arrow, and around the periphery of the drum were disposed a first corona discharge unit 5 adapted to deposit a charge of one polarity on the surface of the highly insulative layer, a second corona discharge unit 6 adapted to deposit a charge of the opposite polarity, a source of uniform light 7, a transfer printing roller 8 for urging an insulative recording paper 10 against the surface of the photosensitive element to transfer print the latent image onto the recording paper 10 and a roller 9 for applying a solvent onto the image forming surface of the highly insulative layer 1 to remove contaminants therefrom.
  • roller 9 for removing the contaminants comprises a roller 9b covered with a layer of felt 9a and a pair of rollers 90 and 9d urged against the layer of felt. These rollers are immersed in an organic solvent 9f such as trichlene (trichloroethylene) contained in a container 9e. Rollers 9c and 9d are used to control the quantity of the solvent carried by felt layer 9a.
  • an organic solvent 9f such as trichlene (trichloroethylene) contained in a container 9e.
  • Rollers 9c and 9d are used to control the quantity of the solvent carried by felt layer 9a.
  • the roller 9 is also rotated in the direction shown by the arrow in FIG. 3 to continuously clean the image forming surface of the photosensitive element with the solvent.
  • latent images were repeatedly formed on the surface of the highly insulative layer 1 and transfer printed ontothe recording paper 10. Up to the 70,000th cycle, clear picture images were always formed. However, beyond 70,000 cycles local defects caused by pin holes began to appear, thus slightly degrading the quality of
  • EXAMPLE 2 A photosensitive element having the same construction as in example 1 was mounted on a rotary metal drum. The assembly was mounted in a vacuum tank evacuated to 10 mm Hg or higher. The metal drum was grounded and a high frequency voltage of 3KHz was applied across the metal drum and an electrode disposed in the vacuum tank. Then vapor of styrene monomer was admitted into the vacuum tank where the monomer was polymerized by the action of the high frequency electric field and the resulting polymer was deposited on the image forming surface of the photosensitive element. After treatment for IS minutes, the assembly of the photosensitive element and the rotary drum was taken out of the vacuum tank and was used to repeatedly form and transfer print latent images as shown in FIG.2.
  • the solvent utilized for removing the contaminants may be any organic solvent that can dissolve and remove mainly HNO Among these organic solvents are trichlene (trichloroethylene), benzene, carbon tetrachloride and methyl alcohol. Especially, trichlene and carbon tetrachloride are preferred because of their high insulating strength.
  • the solvents must not dissolve the highly insulative layer of the photosensitive element. Also it is desirable that the solvents be highly insulative and also highly evaporative so that the latent image can be formed on a dry image forming surface, the solvent is not always required to be highly evaporative since the latent image can be readily formed and transfer printed under wet conditions.
  • the roller 9 may be positioned at any desired location around the periphery of the photosensitive element, and may be brought into contact with the image forming surface continuously or intermittently. Further, it is to be understood that the roller may be replaced by, for example, a replaceable brush of cloth, sponge or felt impregnated with the solvent.
  • the invention has been described in terms of a method and apparatus for electrophotography utilizing a photosensitive element including a highly insulative layer and a photoconductive layer manifesting persistent internal polarization and wherein the latent image is formed on the image forming surface of the highly insulative layer by consecutive application of first and second electric fields and projection of a light image concurrently with the application of the second electric field, it should be understood that the invention can also be applied to ordinary Xerography wherein a photosensitive element including a photoconductive layer is used and the latent image is formed on the image forming surface of the photoconductive layer by first depositing a uniform electric charge by means of corona discharge and then projecting a light image onto the photoconductive layer.
  • the effect of the contaminants on this type of photosensitive element is more serious because it is not provided with a highly insulative layer which is smoother and more resistant to acids than the bare surface of the photoconductive layer.
  • a latent image is formed on the image forming surface of a photosensitive element including a photoconductive layer by depositing an electric charge on said image forming surface by means of corona discharge and projecting a light image upon said photoconductive layer, and the latent image is transfer printed onto a recording medium
  • the improvement which comprises the step of applying an electrically insulative organic solvent onto said image forming surface after said latent image has been transfer printed to remove contaminants formed by the ionization of air by said corona discharge and deposited on said image forming surface.
  • a latent image is formed by the steps of applying a first electric field by means of corona discharge across a photosensitive element including a highly insulative layer and a photoconductive layer exhibiting persistent internal polarization and integrally bonded to said highly insulative layer so as to deposit a charge of one polarity on the surface of said highly insulative layer, applying a second electric field by means of corona discharge across said photosensitive element to deposit a charge of the opposite polarity on the surface of said highly insulative layer, and projecting a light image onto said photoconductive layer concurrently with the application of said second electric field thus forming a latent image corresponding to said light image on the surface of said highly insulative layer, and said latent image is transfer printed onto a recording medium
  • the improvement which comprises applying an electrically insulative organic solvent onto the image forming surface of said highly insulative layer after said latent image has been transfer printed to remove contaminants formed by the ionization of air by said corona discharge and deposited on

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Photoreceptors In Electrophotography (AREA)
  • Electrophotography Using Other Than Carlson'S Method (AREA)
US00179805A 1970-09-25 1971-09-13 Method for removing corona discharge contaminants in electrophotography Expired - Lifetime US3770429A (en)

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US (1) US3770429A (enrdf_load_stackoverflow)
CA (1) CA948011A (enrdf_load_stackoverflow)
DE (1) DE2147247A1 (enrdf_load_stackoverflow)
FR (1) FR2108393A5 (enrdf_load_stackoverflow)
GB (1) GB1312574A (enrdf_load_stackoverflow)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3910697A (en) * 1971-08-02 1975-10-07 Turlabor Ag Process and apparatus for regenerating a photoconductive layer
US3930850A (en) * 1972-07-31 1976-01-06 Mita Industrial Company, Ltd. Process for electrophotographic copying by transfer of electrostatic images
US3947108A (en) * 1974-05-20 1976-03-30 Xerox Corporation Cleaning system
US3957509A (en) * 1974-04-30 1976-05-18 Xerox Corporation Method and apparatus for removing contaminants from an electrostatic imaging surface
US4168973A (en) * 1976-06-05 1979-09-25 Agfa-Gevaert, A.G. Process for the transfer printing of electrostatic charge images using N2 atmosphere
EP0103998A3 (en) * 1982-08-23 1984-07-11 Xerox Corporation Xerographic toner cleaning station
US4664500A (en) * 1984-04-03 1987-05-12 Meteor-Siegen Apparatebau Paul Schmeck Gmbh Method and apparatus for transferring a latent electrical image
US20150023696A1 (en) * 2013-07-17 2015-01-22 Kyocera Document Solutions Inc. Image forming apparatus and light concentrating device

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS547462B2 (enrdf_load_stackoverflow) * 1973-06-15 1979-04-06
JPH0652461B2 (ja) * 1982-05-24 1994-07-06 キヤノン株式会社 電子写真装置、電子写真装置の保守方法および該保守方法に用いるクリーニング部材
KR102784065B1 (ko) * 2021-07-12 2025-03-24 주식회사 포스코 금속소재 프린트 설비 및 이를 이용한 프린트 방법
KR102784064B1 (ko) * 2021-07-12 2025-03-24 주식회사 포스코 금속소재 프린트 설비와 프린트 방법 및 이로부터 얻어진 프린트된 금속소재

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2889758A (en) * 1954-12-24 1959-06-09 Ibm Electrophotographic printer
US3128683A (en) * 1961-04-17 1964-04-14 Xerox Corp Xerographic apparatus
US3394002A (en) * 1964-10-21 1968-07-23 Xerox Corp Charge transfer with liquid layers
US3477846A (en) * 1967-05-01 1969-11-11 Gaf Corp Xerographic charge transfer process
US3576624A (en) * 1967-10-17 1971-04-27 Australia Res Lab Electrostatic printing method employing a pigmented light filter
US3598487A (en) * 1968-01-18 1971-08-10 Tokyo Shibaura Electric Co Electrostatic recording apparatus
US3672930A (en) * 1970-04-02 1972-06-27 Eastman Kodak Co Process of transferring an electrostatic charge pattern without using external pressure or electrical bias

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2889758A (en) * 1954-12-24 1959-06-09 Ibm Electrophotographic printer
US3128683A (en) * 1961-04-17 1964-04-14 Xerox Corp Xerographic apparatus
US3394002A (en) * 1964-10-21 1968-07-23 Xerox Corp Charge transfer with liquid layers
US3477846A (en) * 1967-05-01 1969-11-11 Gaf Corp Xerographic charge transfer process
US3576624A (en) * 1967-10-17 1971-04-27 Australia Res Lab Electrostatic printing method employing a pigmented light filter
US3598487A (en) * 1968-01-18 1971-08-10 Tokyo Shibaura Electric Co Electrostatic recording apparatus
US3672930A (en) * 1970-04-02 1972-06-27 Eastman Kodak Co Process of transferring an electrostatic charge pattern without using external pressure or electrical bias

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Hider, Photoconductor Cleaning System, J. B. M. Technical Disclosure Bulletin, Vol. 9, No. 11, April, 1967, p. 1528. *

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3910697A (en) * 1971-08-02 1975-10-07 Turlabor Ag Process and apparatus for regenerating a photoconductive layer
US3930850A (en) * 1972-07-31 1976-01-06 Mita Industrial Company, Ltd. Process for electrophotographic copying by transfer of electrostatic images
US3957509A (en) * 1974-04-30 1976-05-18 Xerox Corporation Method and apparatus for removing contaminants from an electrostatic imaging surface
US3947108A (en) * 1974-05-20 1976-03-30 Xerox Corporation Cleaning system
US4168973A (en) * 1976-06-05 1979-09-25 Agfa-Gevaert, A.G. Process for the transfer printing of electrostatic charge images using N2 atmosphere
EP0103998A3 (en) * 1982-08-23 1984-07-11 Xerox Corporation Xerographic toner cleaning station
US4664500A (en) * 1984-04-03 1987-05-12 Meteor-Siegen Apparatebau Paul Schmeck Gmbh Method and apparatus for transferring a latent electrical image
US20150023696A1 (en) * 2013-07-17 2015-01-22 Kyocera Document Solutions Inc. Image forming apparatus and light concentrating device
US9304431B2 (en) * 2013-07-17 2016-04-05 Kyocera Document Solutions Inc. Image forming apparatus and light concentrating device

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Publication number Publication date
GB1312574A (en) 1973-04-04
DE2147247A1 (de) 1972-03-30
FR2108393A5 (enrdf_load_stackoverflow) 1972-05-19
CA948011A (en) 1974-05-28

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