US2588699A - Electrophotographic apparatus - Google Patents
Electrophotographic apparatus Download PDFInfo
- Publication number
- US2588699A US2588699A US212812A US21281251A US2588699A US 2588699 A US2588699 A US 2588699A US 212812 A US212812 A US 212812A US 21281251 A US21281251 A US 21281251A US 2588699 A US2588699 A US 2588699A
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- US
- United States
- Prior art keywords
- plate
- electrophotographic
- filaments
- electrophotographic apparatus
- filament
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- 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.)
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- 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
- G03G15/02—Apparatus for electrographic processes using a charge pattern for laying down a uniform charge, e.g. for sensitising; Corona discharge devices
- G03G15/0291—Apparatus for electrographic processes using a charge pattern for laying down a uniform charge, e.g. for sensitising; Corona discharge devices corona discharge devices, e.g. wires, pointed electrodes, means for cleaning the corona discharge device
-
- 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
- Y10S101/00—Printing
- Y10S101/37—Printing employing electrostatic force
Definitions
- This invention relates to electrophotographic apparatus, and particularly to charging apparatus for electrophotographic plates.
- the present invention contemplates an improved charging means for electrophotographic plates, and apparatus embodying the same, in which an ion-producing source, such as an array of emitting filaments is bridged across the plate, and means for applying an electric field, such as a high voltage source, is connected between the ion-producing source and the plate backing while the plate is advanced under the source to deposit an electric charge uniformly over the plate surface.
- an ion-producing source such as an array of emitting filaments
- an electric field such as a high voltage source
- This arrangement is substantially independent of humidity conditions, permits approximate control of the potential applied to the plate surface, is capable of applying higher potentials to the plate, up to the breakdown potential of the plate coating, and applies the potential to the plate without physical contact with the plate coating.
- Figure 1 is a sectional elevation of a portion of an electrophotographic camera showing one embodiment of the charging arrangement of the present invention.
- Figure 2 is a face View of the charging electrode assembly, as viewed from the position of the electrophotographic plate.
- the electrophotographic plate comprises an endless belt ID of conductive material such as metal foil coated on the outer surface with a thin layer ll of photoconductive insulating material, for example sulphur or anthracenc.
- the belt is mounted to run on four insulating rollers or cylinders l2, l3, l4 and I5.
- Roller 14 is arranged to be driven at a relatively slow speed by a worm l6 driven by electric motor H to advance the belt clockwise around its circuit, under control of an electric switch 24.
- the plate charging arrangements are mounted adjacent to roller 12 and comprise a filament grid IQ of platinum or other filament having an electron emission coating.
- the grid I3 is strung on a sutable curved insulating frame l9, which follows the curature of the plate 10 as it passes around roller [2, so that uniform spacing of all the strands of the filament from the plate surface is maintained.
- the frame is shown more clearly in Figure 2.
- the filament is heated to emission temperature by battery 20 connected in series with the filament switch 2 I.
- the filament is also connected to the negative terminal of high voltage generator 22.
- Generator 22 may be a transformer-rectifier system capable of supplying a small current at a potential of 1000 to several thousand volts. It is supplied with A. C. input current through switch 23.
- the plate It) is connected to the positive terminal of generator 22 by sliding contact spring 25.
- Grid I8 is enclosed in a curved metal shield 23 which extends around the outside of the grid.
- the charged area of plate i0 is advanced into camera portion 2'! for exposure, after which it is advanced through a development chamber 28 to a transfer station where sheets of paper may be fed under roller 29 to transfer the developed image as described more fully in my co-pending application, Serial No. 500,207.
- Electrophotographic apparatus comprising, in combination, an electrophotographic element having a layer of photo-conductive insulating material on a conductive base, and means for applying a uniform electrostatic charge to the surface of said layer, said means comprising an ion producing source, means for moving said element relative to said source to bring all areas of said layer under said source, and means to apply an electric field between said source and said conductive base.
- Electrophotographic apparatus comprising, in combination, an electrophotographic element having a layer of photoconductive insulating material on a conductive base, drive means for advancing said electrophotographic element'in a direction substantially parallel to its own surface, an array of filaments overlying and substantially parallel to said surface, said filaments being transverse to the direction of advance of said surface, and a high voltage potential source connected between said filaments and said conductive base to apply an intense electric field between said filaments and said base through the intervening air space and said photoconductive layer.
- Electrophotographic apparatus as claimed in claim 2, in which said array of filaments is enclosed by a conductive shield above said filaments.
- Electrophotographic apparatus as claimed in claim 2, in which means are provided for heating said filaments to emission temperature.
- Electrophotographic apparatus as claimed in claim 4, in which said filaments are coated with an electron emission coating.
- Electrophotographic apparatus comprisin in combination, a cylinder, an electrophotographic element having a base sheet of conductive material extending around said cylinder and a coating of photoconductive insulating material carried thereby, a drive motor to advance said plate around said cylinder a frame mounted adjacent said cylinder and a plurality of filaments strung on said frame in spaced parallel relation.
- said filaments being parallel to the axis of said cylinder and substantially equidistant therefrom, and a high voltage power supply connected between said filaments and said base sheet to apply an intense electric field between said filaments and said base sheet through the intervening air space and said photoconductive coating.
Description
March 11, 1952 c. F. CARLSON ELECTROPHOTOGRAPHIC APPARATUS Original Filed Aug. 27, 1943 HIGH VOLTAGE 6 ENE RATOR FIG. 2
' INVENTOR Patented Mar. 11, 1952 UNITED STATES PATENT OFFICE ELECTROPHOTOGRAPHIC APPARATUS Chester F. Carlson, Fairport, N. Y.
Original application August 27, 1943, Serial No. 500,207. Divided and this application February 26, 1951, Serial No. 212,812
6 Claims. 1
This invention relates to electrophotographic apparatus, and particularly to charging apparatus for electrophotographic plates.
This is a division of my copending application Serial No. 500,207, filed August 27, 1943, now Patent No. 2,551,582.
In the process and apparatus for electrophotography disclosed in Carlson Patents 2,297,691 and 2,357,809 the electrophotographic plate is charged frictionally with a cloth or brush. With this means a sufficiently uniform charge can be produced on the plate to permit the production of acceptable images. However, this means is quite subject to humidity conditions, does not permit control of the voltage applied to the plate, produces a charge which is too weak for some purposes, and produces wear and some contamination of the plate surface.
The present invention contemplates an improved charging means for electrophotographic plates, and apparatus embodying the same, in which an ion-producing source, such as an array of emitting filaments is bridged across the plate, and means for applying an electric field, such as a high voltage source, is connected between the ion-producing source and the plate backing while the plate is advanced under the source to deposit an electric charge uniformly over the plate surface.
This arrangement is substantially independent of humidity conditions, permits approximate control of the potential applied to the plate surface, is capable of applying higher potentials to the plate, up to the breakdown potential of the plate coating, and applies the potential to the plate without physical contact with the plate coating.
Other features of the invention will be apparent from the following specification and the accompanying drawings, in which one embodiment of the invention is illustrated.
In the drawings:
Figure 1 is a sectional elevation of a portion of an electrophotographic camera showing one embodiment of the charging arrangement of the present invention; and
Figure 2 is a face View of the charging electrode assembly, as viewed from the position of the electrophotographic plate.
The charging arrangement illustrated in the drawing is indicated as part of the complete electrophotographic camera or copying unit which is more fully disclosed in my application Serial Number 500,207, now Patent No. 2,551,582 granted May 8, 1951, of which this is a division.
The electrophotographic plate comprises an endless belt ID of conductive material such as metal foil coated on the outer surface with a thin layer ll of photoconductive insulating material, for example sulphur or anthracenc. The belt is mounted to run on four insulating rollers or cylinders l2, l3, l4 and I5. Roller 14 is arranged to be driven at a relatively slow speed by a worm l6 driven by electric motor H to advance the belt clockwise around its circuit, under control of an electric switch 24.
The plate charging arrangements are mounted adjacent to roller 12 and comprise a filament grid IQ of platinum or other filament having an electron emission coating. The grid I3 is strung on a sutable curved insulating frame l9, which follows the curature of the plate 10 as it passes around roller [2, so that uniform spacing of all the strands of the filament from the plate surface is maintained. The frame is shown more clearly in Figure 2. The filament is heated to emission temperature by battery 20 connected in series with the filament switch 2 I. The filament is also connected to the negative terminal of high voltage generator 22. Generator 22 may be a transformer-rectifier system capable of supplying a small current at a potential of 1000 to several thousand volts. It is supplied with A. C. input current through switch 23. The plate It) is connected to the positive terminal of generator 22 by sliding contact spring 25. Grid I8 is enclosed in a curved metal shield 23 which extends around the outside of the grid.
In operation, with switches 2!, 23 and 24 closed, the plate is advanced slowly under filament grid 13 and coating H is given a uniform electric charge over its surface by negative charges driven to it from the filament by the strong electric field produced by the high voltage generator. These charges may comprise both electrons and negative ions produced in the space between grid l8 and coating H.
The charged area of plate i0 is advanced into camera portion 2'! for exposure, after which it is advanced through a development chamber 28 to a transfer station where sheets of paper may be fed under roller 29 to transfer the developed image as described more fully in my co-pending application, Serial No. 500,207.
While the invention has been described as carried out in a specific embodiment it is intended to cover the invention broadly within the spirit and scope of the appended claims.
What is claimed is:
1. Electrophotographic apparatus comprising, in combination, an electrophotographic element having a layer of photo-conductive insulating material on a conductive base, and means for applying a uniform electrostatic charge to the surface of said layer, said means comprising an ion producing source, means for moving said element relative to said source to bring all areas of said layer under said source, and means to apply an electric field between said source and said conductive base.
2. Electrophotographic apparatus comprising, in combination, an electrophotographic element having a layer of photoconductive insulating material on a conductive base, drive means for advancing said electrophotographic element'in a direction substantially parallel to its own surface, an array of filaments overlying and substantially parallel to said surface, said filaments being transverse to the direction of advance of said surface, and a high voltage potential source connected between said filaments and said conductive base to apply an intense electric field between said filaments and said base through the intervening air space and said photoconductive layer.
3. Electrophotographic apparatus as claimed in claim 2, in which said array of filaments is enclosed by a conductive shield above said filaments.
4. Electrophotographic apparatus as claimed in claim 2, in which means are provided for heating said filaments to emission temperature.
5. Electrophotographic apparatus as claimed in claim 4, in which said filaments are coated with an electron emission coating.
6. Electrophotographic apparatus comprisin in combination, a cylinder, an electrophotographic element having a base sheet of conductive material extending around said cylinder and a coating of photoconductive insulating material carried thereby, a drive motor to advance said plate around said cylinder a frame mounted adjacent said cylinder and a plurality of filaments strung on said frame in spaced parallel relation.
said filaments being parallel to the axis of said cylinder and substantially equidistant therefrom, and a high voltage power supply connected between said filaments and said base sheet to apply an intense electric field between said filaments and said base sheet through the intervening air space and said photoconductive coating.
CHESTER F. CARLSON.
No references cited.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US212812A US2588699A (en) | 1943-08-27 | 1951-02-26 | Electrophotographic apparatus |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US500207A US2551582A (en) | 1943-08-27 | 1943-08-27 | Method of printing and developing solvent images |
US212812A US2588699A (en) | 1943-08-27 | 1951-02-26 | Electrophotographic apparatus |
Publications (1)
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US2588699A true US2588699A (en) | 1952-03-11 |
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US212812A Expired - Lifetime US2588699A (en) | 1943-08-27 | 1951-02-26 | Electrophotographic apparatus |
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Cited By (33)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2755526A (en) * | 1952-08-08 | 1956-07-24 | Polygram Casting Company Ltd | Apparatus for making casting moulds or other hollow articles |
US2774921A (en) * | 1953-04-23 | 1956-12-18 | Haloid Co | Apparatus for electrostatically charging insulating image surfaces for electrophotography |
US2831409A (en) * | 1955-07-18 | 1958-04-22 | Haloid Co | Xerographic camera |
US2885556A (en) * | 1955-08-01 | 1959-05-05 | Haloid Xerox Inc | Simultaneous charging device and method |
US2892973A (en) * | 1955-01-26 | 1959-06-30 | Gen Dynamics Corp | Apparatus for imparting electrostatic charges in electrophotography |
US2922883A (en) * | 1955-03-03 | 1960-01-26 | Rca Corp | Electrostatic charging means and method |
US2952241A (en) * | 1955-02-03 | 1960-09-13 | Haloid Xerox Inc | Developer electrode for electrophotographic apparatus |
US2955938A (en) * | 1955-08-01 | 1960-10-11 | Haloid Xerox Inc | Xerography |
US2965481A (en) * | 1955-08-01 | 1960-12-20 | Haloid Xerox Inc | Electrostatic charging and image formation |
US2980834A (en) * | 1956-04-26 | 1961-04-18 | Bruning Charles Co Inc | Charging of photo-conductive insulating material |
US3054897A (en) * | 1956-08-17 | 1962-09-18 | Mason & Sons Ltd E N | Process of and apparatus for printing or copying by electrostatic photography |
US3071645A (en) * | 1959-09-09 | 1963-01-01 | Gen Dynamics Corp | Recorder utilizing electrostatic charges |
DE1172118B (en) * | 1960-03-08 | 1964-06-11 | Australia Res Lab | Machine for electrostatically charging photoconductive material |
US3163753A (en) * | 1961-09-12 | 1964-12-29 | Du Pont | Process and apparatus for electrostatically applying separating and forwarding forces to a moving stream of discrete elements of dielectric material |
US3168022A (en) * | 1956-03-08 | 1965-02-02 | Zindler Lumoprint Kg | Apparatus for producing photocopies |
US3287614A (en) * | 1963-05-27 | 1966-11-22 | Rca Corp | Portable, self-powered, corona charging apparatus |
US3354804A (en) * | 1964-07-23 | 1967-11-28 | Minnesota Mining & Mfg | Developing camera |
DE1280281B (en) * | 1964-06-01 | 1968-10-17 | Rank Xerox Ltd | Method and arrangement for converting an electrical signal into a graphic image |
US3739246A (en) * | 1969-12-17 | 1973-06-12 | Kalle Ag | Process and apparatus for increasing the charge density of insulators |
US3845307A (en) * | 1973-02-22 | 1974-10-29 | Xerox Corp | Combined corona and luminescent discharge |
US3943407A (en) * | 1973-08-01 | 1976-03-09 | Scientific Enterprises, Inc. | Method and apparatus for producing increased quantities of ions and higher energy ions |
DE1797635B1 (en) * | 1966-06-29 | 1977-11-10 | Xerox Corp | ELECTROPHORETOPHOTOGRAPHIC IMAGING PROCEDURE |
WO1980001112A1 (en) * | 1978-11-23 | 1980-05-29 | J Payne | Device for electrostatically charging sheet material |
US4259093A (en) * | 1976-04-09 | 1981-03-31 | Elfi Elektrofilter Ab | Electrostatic precipitator for air cleaning |
US4511244A (en) * | 1983-09-06 | 1985-04-16 | Eastman Kodak Company | Corona generating apparatus and method |
US4591713A (en) * | 1984-01-03 | 1986-05-27 | Xerox Corporation | Efficient, self-limiting corona device for positive or negative charging |
US5153435A (en) * | 1991-05-09 | 1992-10-06 | Xerox Corporation | Planar scorotron device |
US5563688A (en) * | 1994-12-14 | 1996-10-08 | Xerox Corporation | Charging device for charging in one of a plurality of predefined image areas on a surface of an imaging member |
US5587584A (en) * | 1996-03-28 | 1996-12-24 | Xerox Corporation | Apparatus for charging a film on the internal surface of a drum |
US5655186A (en) * | 1996-03-28 | 1997-08-05 | Xerox Corporation | Light blocking ion charging apparatus |
US5659176A (en) * | 1996-03-28 | 1997-08-19 | Xerox Corporation | Scanning corotron |
US5706162A (en) * | 1994-12-14 | 1998-01-06 | Xerox Corporation | Corona generating device |
US5723863A (en) * | 1996-03-28 | 1998-03-03 | Xerox Corporation | Ion charging apparatus with light blocking capability |
-
1951
- 1951-02-26 US US212812A patent/US2588699A/en not_active Expired - Lifetime
Non-Patent Citations (1)
Title |
---|
None * |
Cited By (35)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2755526A (en) * | 1952-08-08 | 1956-07-24 | Polygram Casting Company Ltd | Apparatus for making casting moulds or other hollow articles |
US2774921A (en) * | 1953-04-23 | 1956-12-18 | Haloid Co | Apparatus for electrostatically charging insulating image surfaces for electrophotography |
US2892973A (en) * | 1955-01-26 | 1959-06-30 | Gen Dynamics Corp | Apparatus for imparting electrostatic charges in electrophotography |
US2952241A (en) * | 1955-02-03 | 1960-09-13 | Haloid Xerox Inc | Developer electrode for electrophotographic apparatus |
US2922883A (en) * | 1955-03-03 | 1960-01-26 | Rca Corp | Electrostatic charging means and method |
US2831409A (en) * | 1955-07-18 | 1958-04-22 | Haloid Co | Xerographic camera |
US2965481A (en) * | 1955-08-01 | 1960-12-20 | Haloid Xerox Inc | Electrostatic charging and image formation |
US2955938A (en) * | 1955-08-01 | 1960-10-11 | Haloid Xerox Inc | Xerography |
US2885556A (en) * | 1955-08-01 | 1959-05-05 | Haloid Xerox Inc | Simultaneous charging device and method |
US3168022A (en) * | 1956-03-08 | 1965-02-02 | Zindler Lumoprint Kg | Apparatus for producing photocopies |
US2980834A (en) * | 1956-04-26 | 1961-04-18 | Bruning Charles Co Inc | Charging of photo-conductive insulating material |
US3054897A (en) * | 1956-08-17 | 1962-09-18 | Mason & Sons Ltd E N | Process of and apparatus for printing or copying by electrostatic photography |
US3071645A (en) * | 1959-09-09 | 1963-01-01 | Gen Dynamics Corp | Recorder utilizing electrostatic charges |
DE1172118B (en) * | 1960-03-08 | 1964-06-11 | Australia Res Lab | Machine for electrostatically charging photoconductive material |
US3163753A (en) * | 1961-09-12 | 1964-12-29 | Du Pont | Process and apparatus for electrostatically applying separating and forwarding forces to a moving stream of discrete elements of dielectric material |
US3287614A (en) * | 1963-05-27 | 1966-11-22 | Rca Corp | Portable, self-powered, corona charging apparatus |
DE1280281B (en) * | 1964-06-01 | 1968-10-17 | Rank Xerox Ltd | Method and arrangement for converting an electrical signal into a graphic image |
US3354804A (en) * | 1964-07-23 | 1967-11-28 | Minnesota Mining & Mfg | Developing camera |
DE1797635B1 (en) * | 1966-06-29 | 1977-11-10 | Xerox Corp | ELECTROPHORETOPHOTOGRAPHIC IMAGING PROCEDURE |
DE1797620B1 (en) * | 1966-06-29 | 1977-11-10 | Xerox Corp | ELECTROPHORETOPHOTOGRAPHIC IMAGING PROCEDURE |
DE1797619B1 (en) * | 1966-06-29 | 1977-11-24 | Xerox Corp | ELECTROPHORETOPHOTOGRAPHIC IMAGING PROCEDURE |
US3739246A (en) * | 1969-12-17 | 1973-06-12 | Kalle Ag | Process and apparatus for increasing the charge density of insulators |
US3845307A (en) * | 1973-02-22 | 1974-10-29 | Xerox Corp | Combined corona and luminescent discharge |
US3943407A (en) * | 1973-08-01 | 1976-03-09 | Scientific Enterprises, Inc. | Method and apparatus for producing increased quantities of ions and higher energy ions |
US4259093A (en) * | 1976-04-09 | 1981-03-31 | Elfi Elektrofilter Ab | Electrostatic precipitator for air cleaning |
WO1980001112A1 (en) * | 1978-11-23 | 1980-05-29 | J Payne | Device for electrostatically charging sheet material |
US4511244A (en) * | 1983-09-06 | 1985-04-16 | Eastman Kodak Company | Corona generating apparatus and method |
US4591713A (en) * | 1984-01-03 | 1986-05-27 | Xerox Corporation | Efficient, self-limiting corona device for positive or negative charging |
US5153435A (en) * | 1991-05-09 | 1992-10-06 | Xerox Corporation | Planar scorotron device |
US5563688A (en) * | 1994-12-14 | 1996-10-08 | Xerox Corporation | Charging device for charging in one of a plurality of predefined image areas on a surface of an imaging member |
US5706162A (en) * | 1994-12-14 | 1998-01-06 | Xerox Corporation | Corona generating device |
US5587584A (en) * | 1996-03-28 | 1996-12-24 | Xerox Corporation | Apparatus for charging a film on the internal surface of a drum |
US5655186A (en) * | 1996-03-28 | 1997-08-05 | Xerox Corporation | Light blocking ion charging apparatus |
US5659176A (en) * | 1996-03-28 | 1997-08-19 | Xerox Corporation | Scanning corotron |
US5723863A (en) * | 1996-03-28 | 1998-03-03 | Xerox Corporation | Ion charging apparatus with light blocking capability |
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