EP0000045A1 - Appareil de copie électrophotographique comprenant un dispositif pour effacer des images électrostatiques résiduelles - Google Patents

Appareil de copie électrophotographique comprenant un dispositif pour effacer des images électrostatiques résiduelles Download PDF

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Publication number
EP0000045A1
EP0000045A1 EP78100083A EP78100083A EP0000045A1 EP 0000045 A1 EP0000045 A1 EP 0000045A1 EP 78100083 A EP78100083 A EP 78100083A EP 78100083 A EP78100083 A EP 78100083A EP 0000045 A1 EP0000045 A1 EP 0000045A1
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EP
European Patent Office
Prior art keywords
radiation
spectral range
light
maximum
energy
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.)
Granted
Application number
EP78100083A
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German (de)
English (en)
Other versions
EP0000045B1 (fr
Inventor
Eberhard Bayer
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.)
Siemens AG
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Siemens AG
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Filing date
Publication date
Application filed by Siemens AG filed Critical Siemens AG
Publication of EP0000045A1 publication Critical patent/EP0000045A1/fr
Application granted granted Critical
Publication of EP0000045B1 publication Critical patent/EP0000045B1/fr
Expired 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
    • G03G21/00—Arrangements not provided for by groups G03G13/00 - G03G19/00, e.g. cleaning, elimination of residual charge
    • G03G21/06—Eliminating residual charges from a reusable imaging member
    • G03G21/08—Eliminating residual charges from a reusable imaging member using optical radiation

Definitions

  • the invention relates to a device in an electrophotographic copying device, as specified in the preamble of claim 1.
  • Electrophotographic copying devices are known from the prior art, in which an electrostatic charge image is generated in a layer of a photoconductive material such as arsenic-selenium.
  • the layer is charged with the aid of a corona discharge.
  • An inscribed charge image is usually deleted using light from a spectral range of maximum photoconductivity generation.
  • a spectral range of maximum photoconductivity generation For the arsenic selenium (As 2 Se 3 ) given by way of example, this spectral range lies in the green light range at approximately 500 nm.
  • the charge image is generally written in with light of the same spectral range. It However, investigations have already been carried out using light from the red spectral range. With this measure, the writing of an electrostatic charge image is achieved, which is not eliminated by the usual corona charging, but is regenerated.
  • the charge image inscribed in this way was also deleted at die-. registered letter as usual with the green light indicated above.
  • FIG. 1 shows schematically the result to be achieved with the invention.
  • the diagram shows the surface charge potential over the number of successive charges with a sequence of points 1.
  • sequence 2 consisting of crosses is entered. Each point or cross corresponds to a potential measurement after charging a drum, as is customary in such copying devices, on which the photoconductive layer of As-Se is located. No write exposure is involved in these rounds of episodes 1 and 2. From the diagram or from the difference between sequence 1 and sequence 2, one can clearly see this one stabilizing effect which is achieved with the measure according to the invention.
  • Circles of a sequence 3 denote the potential of the photoconductive layer which is suitable for one of the revolutions of the drum, i.e. for one of the successive copying processes, in the case of write exposure with such light, which according to the known prior art - see e.g. U.S. Patent 3,511,649 - leads to severe potential fatigue.
  • the representation is normalized to these potential values 3 with respect to the ordinate.
  • the potential difference which can be evaluated as a contrast, is significantly increased, which results from the height of the point sequence 1 or crosses 2 and the sequence 3 of the circles.
  • the advantage described above also has the further advantage that, after a writing exposure as indicated with sequence 3 of the circles, subsequent ones Cycles of a sequence 4 (again shown with dots) in which write exposure is no longer provided, the same potential value as in sequence 1 is immediately restored and is also retained for the further cycles.
  • the point sequences 1 and 4 thus together represent a constant charging of the surface potential independent of write exposure processes, which is achieved with the measures according to the invention for all cycles in which there is no write exposure (regardless of the number of previous such cycles).
  • the diagram in FIG. 1 furthermore shows which potential values of the surface potential occur on the other hand if, for example, a filtered incandescent lamp is used in accordance with the known prior art.
  • Sequence 5 which is marked by triangles, indicates the sequence of charges of the layer which occurs from cycle to cycle and is counted after the last write exposure, in the event that the measures according to the invention are not applied.
  • the invention therefore provides for the light used for the extinction to be composed of two spectral ranges.
  • One spectral range is about + 10% around a radiation wavelength at which maximum photoconductivity generation can be achieved in the photoconductive material.
  • this value of the maximum 12 is 500 nm.
  • the width indicated with + 10% characterizes the spectral range in which light is equivalent in terms of the generation of photoconductivity in the respective material.
  • the integral of the radiation energy over this range is effective in the photoconductive material for photoconductivity generation.
  • the other Spectral range in which the wavelength for light of the maximum of the product of photoconductivity generation and penetration depth lies.
  • the effect of the light 13, for the wavelength of which the product of photoconductivity generation and penetration depth is maximum, corresponds physically to an amplification effect due to changed space charge conditions, which produce a higher photoconductivity for light of all wavelength ranges which are shorter-wavelength than the light of this spectral range 13.
  • the light of the two spectral ranges provided according to the invention can thus be light from a single radiation source which is provided, for example, with appropriate filters.
  • this dimensioning according to the invention can also be realized with the aid of two light sources, one of which emits white light and the other light graphically only of the spectral range of the maximum photoconductivity generation 11, in the case of the As 2 Se 3 green light. The light in the area of the maximum product can therefore be part of this white light.
  • the spectral range of maximum photoconductivity generation is designated with 11, with 12 indicating the wavelength of the maximum plotted on the abscissa. With ⁇ 10%, the Be range 11 defined around this wavelength value 12. It should be pointed out that the specification ⁇ 10% is an approximate specification which is dependent on the respective photoconductive material anyway and is essentially intended to give the person skilled in the art an indication.
  • the range of the wavelengths of the maximum of the product of photoconductivity generation and penetration depth is indicated in a corresponding manner at 13. This lies around a wavelength 14.
  • the line 16 shown in broken lines in FIG. 2 indicates additional radiation which may be present, for example, and which lies outside the spectral ranges mentioned. Spectral components of this radiation that fall into the respective spectral ranges 11 and 13 are to be included in the energy values of the ranges 11 and 13, respectively.
  • FIG. 3 shows schematically a copying device known per se, in which the invention is implemented.
  • a drum is designated; on which the photosensitive layer 211 is located.
  • a device for a corona discharge is indicated.
  • 24 denotes a device for writing exposure in which there is a light source 241 for, for example, red light.
  • a printing device for producing the electrostatic copies is indicated at 25.
  • 26 a device is designated in which the Erfin is realized.
  • the light source 261 located in this device 26 can, for example using a filter 262, deliver both the light of the spectral range of maximum photoconductivity generation and the light of the spectral range of the maximum of the specified product.
  • a second device 26 'with a light source 261 is generated, which generates the required light of the other spectral range.
  • a second device 26 'with a light source 261 is generated, which generates the required light of the other spectral range.
  • these two exposures are carried out in succession (not separated from one another, for example by a corona charge or a copying process), namely between the printing process with the device 25 and the (re) charging of the corona. Facility 23.
  • the erasure exposure according to the invention which can also be addressed as a pre-exposure before the corona charge, results in an increased photosensitivity of the material of the layer for the write exposure with a light long-wave spectral range.
  • "Long-wave” is to be understood as a wavelength range in which the light energy of the band edge of the respective corresponds essentially to photoconductive material. For As 2 Se 3 , this is a range from approximately 550 to 650 nm.
  • registered letters with such a long wavelength had to be ruled out in practice, as can be seen, for example, from US Pat. No. 3,511,649.

Landscapes

  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Discharging, Photosensitive Material Shape In Electrophotography (AREA)
  • Photoreceptors In Electrophotography (AREA)
  • Exposure Or Original Feeding In Electrophotography (AREA)
  • Light Sources And Details Of Projection-Printing Devices (AREA)
EP78100083A 1977-06-14 1978-06-02 Appareil de copie électrophotographique comprenant un dispositif pour effacer des images électrostatiques résiduelles Expired EP0000045B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE2726805 1977-06-14
DE2726805A DE2726805C3 (de) 1977-06-14 1977-06-14 Elektrofotografische Kopiervorrichtung mit einer Einrichtung zum Loschen eines elektrostatischen Ladungsbildes

Publications (2)

Publication Number Publication Date
EP0000045A1 true EP0000045A1 (fr) 1978-12-20
EP0000045B1 EP0000045B1 (fr) 1981-10-21

Family

ID=6011507

Family Applications (1)

Application Number Title Priority Date Filing Date
EP78100083A Expired EP0000045B1 (fr) 1977-06-14 1978-06-02 Appareil de copie électrophotographique comprenant un dispositif pour effacer des images électrostatiques résiduelles

Country Status (7)

Country Link
US (1) US4170413A (fr)
EP (1) EP0000045B1 (fr)
JP (1) JPS547347A (fr)
AT (1) AT359827B (fr)
CH (1) CH622628A5 (fr)
DE (1) DE2726805C3 (fr)
IT (1) IT1096641B (fr)

Families Citing this family (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6027026B2 (ja) * 1977-06-17 1985-06-26 キヤノン株式会社 電子写真方法及び装置
JPS5557875A (en) * 1978-06-24 1980-04-30 Mita Ind Co Ltd Transfer type electrostatic copying machine
JPS55101981A (en) * 1979-01-31 1980-08-04 Ricoh Co Ltd Electrophotographic copying method
JPS5624383A (en) * 1979-08-02 1981-03-07 Minolta Camera Co Ltd Light erasing device in transfer type copying machine
JPS57212458A (en) * 1981-06-24 1982-12-27 Ricoh Co Ltd Electrophotographic copying method
JPS587649A (ja) * 1981-07-08 1983-01-17 Ricoh Co Ltd 電子写真複写方法及びその装置
JPS58114082A (ja) * 1981-12-28 1983-07-07 Ricoh Co Ltd 静電記録方法
JPS58137873A (ja) * 1982-02-10 1983-08-16 Ricoh Co Ltd 感光体除電方法
JPS6014255A (ja) * 1983-07-05 1985-01-24 Toshiba Corp 画像形成装置
JPS6014254A (ja) * 1983-07-05 1985-01-24 Toshiba Corp 電子写真装置
JPS6082669U (ja) * 1983-11-10 1985-06-07 株式会社リコー 感光体光除電器
JPS6197681A (ja) * 1984-10-17 1986-05-16 Sharp Corp 電子写真感光体の光疲労防止方法
JPS6197668A (ja) * 1984-10-17 1986-05-16 Sharp Corp 電子写真感光体の帯電電位安定化装置
DE3536836A1 (de) * 1984-10-17 1986-04-17 Sharp K.K., Osaka Entladevorrichtung fuer ein kopiergeraet
JPS6197683A (ja) * 1984-10-17 1986-05-16 Sharp Corp 電子写真感光体の帯電電位安定化方法
JPS6197667A (ja) * 1984-10-17 1986-05-16 Sharp Corp 電子写真感光体の帯電電位安定化方法
DE3901496A1 (de) * 1988-01-21 1989-08-03 Fuji Electric Co Ltd Elektrofotografischer drucker
US5606398A (en) * 1995-04-28 1997-02-25 Minnesota Mining And Manufacturing Company Reduction of residual potential and ghosting in a photoconductor

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2037456A1 (de) * 1969-07-28 1971-02-11 Canon K K , Tokyo Verfahren zum Beeinflussen der Bild dichte in elektrofotografischen Kopiervor gangen
DE2646150A1 (de) * 1975-10-14 1977-04-28 Eastman Kodak Co Elektrophotographische kopiervorrichtung

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3481669A (en) * 1965-03-01 1969-12-02 Xerox Corp Photo-charging of xerographic plates
US3666364A (en) * 1965-12-01 1972-05-30 Canon Kk Electrophotographic apparatus
US3511649A (en) * 1966-05-02 1970-05-12 Xerox Corp Process of reducing fatigue in photoconductive glasses
US3615395A (en) * 1966-09-28 1971-10-26 Canon Camera Co Electrostatic and electrophotographic variable contrast image-forming methods
JPS5025233A (fr) * 1972-09-20 1975-03-17
US3930853A (en) * 1973-12-06 1976-01-06 Xerox Corporation Accelerating aging method for selenium-arsenic photoconductors
US3963488A (en) * 1974-09-03 1976-06-15 Gaf Corporation Contrast of electrostatic latent images with a light flooding step

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2037456A1 (de) * 1969-07-28 1971-02-11 Canon K K , Tokyo Verfahren zum Beeinflussen der Bild dichte in elektrofotografischen Kopiervor gangen
DE2646150A1 (de) * 1975-10-14 1977-04-28 Eastman Kodak Co Elektrophotographische kopiervorrichtung

Also Published As

Publication number Publication date
AT359827B (de) 1980-12-10
EP0000045B1 (fr) 1981-10-21
DE2726805A1 (de) 1978-12-21
IT7824439A0 (it) 1978-06-12
DE2726805C3 (de) 1981-01-22
US4170413A (en) 1979-10-09
JPH0514277B2 (fr) 1993-02-24
IT1096641B (it) 1985-08-26
CH622628A5 (fr) 1981-04-15
JPS547347A (en) 1979-01-20
DE2726805B2 (de) 1980-05-08
ATA408778A (de) 1980-04-15

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