US3905811A - Electrophotography using CRT exposure and liquid developer - Google Patents

Electrophotography using CRT exposure and liquid developer Download PDF

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Publication number
US3905811A
US3905811A US411199A US41119973A US3905811A US 3905811 A US3905811 A US 3905811A US 411199 A US411199 A US 411199A US 41119973 A US41119973 A US 41119973A US 3905811 A US3905811 A US 3905811A
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United States
Prior art keywords
image
photoconductive layer
radiation
electrostatic
photosensitive member
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Expired - Lifetime
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US411199A
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English (en)
Inventor
Koichiro Fujioka
Takeo Tano
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Iwatsu Electric Co Ltd
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Iwatsu Electric Co Ltd
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Filing date
Publication date
Application filed by Iwatsu Electric Co Ltd filed Critical Iwatsu Electric Co Ltd
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Publication of US3905811A publication Critical patent/US3905811A/en
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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
    • G03G15/04—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material
    • G03G15/045—Apparatus 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

Definitions

  • ABSTRACT A method for forming an electrostatic image on a photosensitive member having a photoconductive layer bonded to a conductive layer by applying a charge of one polarity to the photoconductive layer, and then exposing the photoconductive layer to a pattern of image radiation to form an electrostatic latent image.
  • the photoconductive layer is then exposed to blanket radiation and the electrostatic latent image is then developed by using a liquid developer having the same polarity as the charge applied to the photoconductive layer to form a visual image in a relatively shortened exposure time.
  • the foregoing and other objects are in one aspect attained by the provision of a method for forming an electrostatic image on a photosensitive member having a photoconductive layer bonded to a conductive layer by applying a charge of one polarity to the photoconductive layer, and then exposing the photoconductive layer to a pattern of image radiation to thereby form an electrostatic image.
  • the photoconductive layer is then exposed to blanket radiation and then the electrostatic image is developed by using a liquid developer having the same polarity as the charge applied to the photoconductive layer to thereby form a visual image, whereby the time to expose the photoconductive layer to the pattern of image radiation is shortened as compared with conventional electrophotographic methods.
  • FIG. 1 wherein a preferred embodiment of the apparatus for practicing the method of forming an image in ele'ctrophotography according to the present invention is shown as including a photosensitive paper having a photoconductive layer bonded to a conductive layer fed from a roll of copying paper 1 which is sent to a cutter 2.
  • the photosensitive paper is cut to a required length by the cutter 2 and is then fed to a conventional charging apparatus 3, wherein the photosensitive paper receives a corona negative discharge thereon.
  • the charged photosensitive paper then enters conventional exposure apparatus 4 and stops there, wherein an electrostatic latent image is formed on the photosensitive paper in accordance with the light-anddark pattern of the original image which is screened by a cathode ray tube'6 through a mirror 7 and a lens 8.
  • the photosensitive paper is then irradiated over approximately the range of from 5 lux seconds to 20 lux seconds, but preferably over approximately the range of from 10 lux seconds to 15 lux seconds by a tungsten lamp 10, a fluorescent lamp or the like having an intensity of approximately 30 lux which illuminates white and blue color thereon.
  • the photosensitive paper is then developed at a higher density than ordinary liquid toner with the same polarity as the charge applied to the photosensitive paper.
  • the photosensitive paper is developed at a density over approximately the range of 1.2 times to 2 times that of ordinary liquid toner which comprises an electrically insulating carrier liquid, a pigment such as carbon black or coloring agent and a resin.
  • the particles of toner are negatively charged and are repelled by the electrostatic image and attracted by the background area.
  • the photosensitive paper is then sent to a stacker I1 and is fed at a speed of, for example, 0.35cm per second.
  • FIGS. 2 and 3 the present invention will be more readily apparent from the characteristic curves of light decay and dark decay therein shown.
  • the solid lines and dotted lines respectively indicate a conventional sample and a sample of the present invention.
  • a characteristic curve of light decay is shown by the dotted line 13 of FIG. 2 when weak light emitted from the tungsten lamp (FIG. 1) irradiates uniformly the photosensitive paper exposed to the pattern of image radiation of the cathode ray tube 6 (FIG. 1 According to FIG. 2, it is seen that conventionally an amount of exposure time 15 is required to reach an adequate surface potential point 14 whereby the photosensitive paper will be developed'to form a visual image. On the otherhand, with the present invention, it is seen that the photosensitive paper need be exposed to the pattern of image radiation to form an electrostatic image according to the dark-and-light pattern of the original at the exposure time 16 which corresponds to only 50% to 60% of a conventional adequate amount of exposure time 15.
  • the photosensitive paper when the surface potential is decreased to the potential point 17 which corresponds to the potential point 14 of the prior art after the surface of the photosensitive paper is exposed to the tungsten lamp 10, the photosensitive paper is developed. Asv a result, an adequate amount 'of exposure time may be decreased with the present invention to approximately the exposure amount 18 as shown in FIG. 2 because the time required to be decreased to a potential point 17 after exposing the photosensitive paper to blanket radiation is short enough to be negligible.
  • the amount of exposure may be decreased to about 50% of the amount of conventional exposure time by exposing the photosensitive paper to a tungsten lamp and the like. It should further be apparent that with the present invention if the intensity of the lamp and the material of the photosensitive paper are predetermined that the exposure time may be shortened to about 50% of conventional exposure time. It should be further understood that the details of the method for forming an electrostatic image dessribed above may be varied by those skilled in the art in an obvious manner without departing from the spirit of the present invention. Therefore the preceeding detailed description of a preferred embodiment of the present invention is not intended to limit the scope of the invention which is to be determined only from the following claims.
  • the amount of said blanket radiation is in the range of from approximately 10 lux seconds to 15 lux seconds.
  • said blanket radiation is accomplished by a tungsten lamp. 4. In a method for forming an electrostatic image on a photosensitive member according to claim '1, said blanket radiation is accomplished by a fluorescent lamp.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Exposure Or Original Feeding In Electrophotography (AREA)
  • Control Or Security For Electrophotography (AREA)
  • Wet Developing In Electrophotography (AREA)
US411199A 1973-02-08 1973-10-31 Electrophotography using CRT exposure and liquid developer Expired - Lifetime US3905811A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP48015944A JPS49106332A (enrdf_load_stackoverflow) 1973-02-08 1973-02-08

Publications (1)

Publication Number Publication Date
US3905811A true US3905811A (en) 1975-09-16

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
US411199A Expired - Lifetime US3905811A (en) 1973-02-08 1973-10-31 Electrophotography using CRT exposure and liquid developer

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US (1) US3905811A (enrdf_load_stackoverflow)
JP (1) JPS49106332A (enrdf_load_stackoverflow)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS50124644A (enrdf_load_stackoverflow) * 1974-03-06 1975-09-30
JPS5460938A (en) * 1977-10-22 1979-05-16 Ricoh Co Ltd Electrophotographic method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2756676A (en) * 1953-05-04 1956-07-31 Haloid Co Method for the production of electrophotographic prints
US2979403A (en) * 1958-10-24 1961-04-11 Rca Corp Electrostatic printing
US3525612A (en) * 1965-06-16 1970-08-25 Eastman Kodak Co Electrophotographic reproduction process employing a light sensitive material and a photoconductive material
US3558308A (en) * 1967-07-13 1971-01-26 Itek Corp Process for producing photographic images with photosensitive materials and products produced thereby

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS50128U (enrdf_load_stackoverflow) * 1973-05-04 1975-01-06

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2756676A (en) * 1953-05-04 1956-07-31 Haloid Co Method for the production of electrophotographic prints
US2979403A (en) * 1958-10-24 1961-04-11 Rca Corp Electrostatic printing
US3525612A (en) * 1965-06-16 1970-08-25 Eastman Kodak Co Electrophotographic reproduction process employing a light sensitive material and a photoconductive material
US3558308A (en) * 1967-07-13 1971-01-26 Itek Corp Process for producing photographic images with photosensitive materials and products produced thereby

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Publication number Publication date
JPS49106332A (enrdf_load_stackoverflow) 1974-10-08

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