US3560203A - Electrophotographic developing process - Google Patents

Electrophotographic developing process Download PDF

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Publication number
US3560203A
US3560203A US680227A US3560203DA US3560203A US 3560203 A US3560203 A US 3560203A US 680227 A US680227 A US 680227A US 3560203D A US3560203D A US 3560203DA US 3560203 A US3560203 A US 3560203A
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United States
Prior art keywords
light sensitive
sensitive layer
electric field
band
voltage
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.)
Expired - Lifetime
Application number
US680227A
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English (en)
Inventor
Satoru Honjo
Masamichi Sato
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.)
Fujifilm Holdings Corp
Original Assignee
Fuji Photo Film Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Fuji Photo Film Co Ltd filed Critical Fuji Photo Film Co Ltd
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Publication of US3560203A publication Critical patent/US3560203A/en
Anticipated expiration legal-status Critical
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G13/00—Electrographic processes using a charge pattern
    • G03G13/06—Developing
    • G03G13/10—Developing using a liquid developer, e.g. liquid suspension

Definitions

  • the improvement comprising varying said external voltage so as to be synchronized with the attenuation characteristics of a light sensitive layer in contact with the liquid developing solution, and thereby applying a voltage sufficient to just negative an electric field by electric charges of a maximum charge density or a voltage slightly less than that.
  • This invention relates to an electrophotographic developing process and more particularly, it is concerned with a developing process wherein a reversal development is carried out while applying a voltage.
  • an electrostatically detecting powder (which will hereinafter be referred to as toner) is adhered to areas where electrostatic charges are present or the toner is adhered to areas where electrostatic charges are not present, the latter being called a reversal developing process.
  • a light sensitive material comprising an electrically conductive support and a photoconductive layer, such as an amorphous selenium or a mixture of zinc oxide powder and a resin.
  • the light sensitive layer is uniformly charged by a suitable method, for example, by a corona discharge in a dark place, and then exposed to light imagcwise, whereby the electric charges on the exposed light sensitive layer are neutralized and eliminated, while the electric charges on the other areas remain. Consequently, the electrostatic charges appear as an image on the light sensitive layer according to the light image.
  • a toner having the same sign as the electric charges on the light sensitive layer is contacted therewith, it adheres to the charge-free areas.
  • the distribution of electric field on the light sensitive layer is represented by electric lines of force in FIG. 1.
  • FIG. 1 is an illustrative representation of the distribution of electric field on the light sensitive layer in the electrophotographic process
  • FIG. 2 is an illustrative representation of the effect of and adjacent electrode used for preventing the edge effect
  • FIG. 3 is an illustrative representation of the application of a voltage to the light sensitive layer of FIG. 2;
  • FIG. 4 is a graph representing the dark attenuation characteristics of the charged light sensitive layer.
  • FIG. 5 is a graph representing the dark attenuation characteristics in a case where the charged light sensitive layer is allowed to stand in air for a short time, and then is immersed in an insulating liquid.
  • the process is characterized by varying the external voltage so as to be synchronized with the attenuation characteristics of a light sensitive layer and thereby applying constantly a voltage sutficient to just negative an electric field by electric charges of maximum charge density on the light sensitive layer or a voltage slightly less than that, or applying a constant external voltage calculated by, considering the strength of the electric field attenuating during developing according to the attenuation characteristics of the light sensitive layer, subtracting at least a voltage corresponding to the electric field.
  • FIG. 1a illustrates the direction and distribution of electric lines of force in cross section where there are positive charges of a band form on light sensitive material 1 comprising light sensitive layer 11 and electrically conductive support 12.
  • FIG. lb represents a distribution of electric field near the surface of the light sensitive layer in adirection vertical to the light sensitive layer corresponding to FIG. 1a.
  • the horizontal axis corresponds to the position of the light sensitive layer and the vertical axis represents the strength of the electric field.
  • a positive electric field (a direction vertically outwards from the surface of the light sensitive layer is defined as positive) within a range in which there are positive charges, but the distribution of the electric field is not uniform.
  • the strength of the electric field is relatively small inside a band part (which will be hereinafter referred to as band) where there are electric charges, maximum near the ends of the band, and substantially zero at the ends of the band.
  • the electric field is negative outside the band, the strength thereof being maximum near the ends of the band and getting smaller farther from the band.
  • FIGS. 2a and b represent the electric lines of force and distribution of electric field in this case. That is, FIG. 2a shows that the electric lines of force are substantially vertical to the light sensitive layer when adiacent electrode 2 is arranged substantially in parallel near light sensitive layer 11, while b gives the distribution state of electric field at this time. There are thus obtained a positive electric field of a substantially uniform strength inside the band and a negative electric field next to zero outside the band.
  • FIG. 3b shows the distribution of electric field in this case which is substantially zero inside the band and a substantially uniform, negative value outside the band.
  • an applied voltage Va may be less than that.
  • Va just neutralizes the electric field by positive charges of the band
  • Va is at its upper limit, and, where Va is less than this, there are formed a positive electric field inside the band and a negative electric field outside the band.
  • This negative electric field may have only the strength required to cause a toner to adhere to the light sensitive layer.
  • the light sensitive layer in the case of liquid developing, is often attacked by an insulating liquid whereby the voltage is rapidly attenuated.
  • the resin being a silicone resin
  • the resin absorbs many of organic insulating liquids even though it is not dissolved therein and the attenuation becomes so rapid that development cannot be carried out.
  • An initial potential e.g., 500 v., becomes sometimes next to zero after about 10 seconds when contacted with kerosene.
  • FIG. 5 shows the dark attenuation in air and in an insulating liquid, the former being represented by curve A, and the latter by curve B.
  • the surface potential decreases to E This ought to be E at 2:T if in air. It is found often that E E E E E
  • an example is taken where there are electric charges of a constant charge density on certain areas of a light sensitive layer and no electric charge on another area. Since the charge density is continuously distributed from zero to maximum on a light sensitivity according to a light image in fact however, it is to be understood that, in the practical reversal development, areas of maximum charge density may correspond to areas of constant charge density in the foregoing illustration.
  • An electrophotographic developing process wherein reversal development is carried out on a photoconductive layer while applying an external voltage, the attenuation characteristics of said photoconductive material being such that the dark attenuation thereof decreases with respect to time during said reversal development, said process comprising the steps of:

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Photoreceptors In Electrophotography (AREA)
  • Electrophotography Using Other Than Carlson'S Method (AREA)
  • Developing For Electrophotography (AREA)
  • Wet Developing In Electrophotography (AREA)
US680227A 1966-11-02 1967-11-02 Electrophotographic developing process Expired - Lifetime US3560203A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP41072265A JPS5114030B1 (de) 1966-11-02 1966-11-02

Publications (1)

Publication Number Publication Date
US3560203A true US3560203A (en) 1971-02-02

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ID=13484265

Family Applications (1)

Application Number Title Priority Date Filing Date
US680227A Expired - Lifetime US3560203A (en) 1966-11-02 1967-11-02 Electrophotographic developing process

Country Status (5)

Country Link
US (1) US3560203A (de)
JP (1) JPS5114030B1 (de)
DE (1) DE1597844C3 (de)
FR (1) FR1604137A (de)
GB (1) GB1165038A (de)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3784397A (en) * 1970-02-04 1974-01-08 Xerox Corp Imaging system
US3804659A (en) * 1970-12-10 1974-04-16 Fuji Photo Film Co Ltd Electrophotographic reversal development process for enhancing the quality of the developed image
US3836384A (en) * 1968-10-01 1974-09-17 Fuji Photo Film Co Ltd Imaging systems
US3885960A (en) * 1972-12-11 1975-05-27 Bell & Howell Co Method of development of liquid electrostatic images using an hydrophobic barrier liquid
US3886900A (en) * 1972-08-01 1975-06-03 Cellophane Sa Apparatus for developing a latent charged image
US3901698A (en) * 1971-12-10 1975-08-26 Rank Xerox Ltd Method of reversal development using two electrostatic developers
US3918966A (en) * 1972-09-28 1975-11-11 Commw Of Australia Liquid development of an electrical image in which a pulsating field is employed
US3951653A (en) * 1973-08-30 1976-04-20 Rank Xerox Ltd. Method of preventing toner build-up on electrodes during liquid development
US5051329A (en) * 1989-12-19 1991-09-24 Dximaging Reversal development of latent electrostatic images on xeroprinting masters
US20070178228A1 (en) * 2006-01-27 2007-08-02 Shiu Hei M Method for fabricating a PCB

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58162961A (ja) * 1982-03-24 1983-09-27 Fuji Photo Film Co Ltd 平板印刷板の製造方法

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3836384A (en) * 1968-10-01 1974-09-17 Fuji Photo Film Co Ltd Imaging systems
US3784397A (en) * 1970-02-04 1974-01-08 Xerox Corp Imaging system
US3804659A (en) * 1970-12-10 1974-04-16 Fuji Photo Film Co Ltd Electrophotographic reversal development process for enhancing the quality of the developed image
US3901698A (en) * 1971-12-10 1975-08-26 Rank Xerox Ltd Method of reversal development using two electrostatic developers
US3886900A (en) * 1972-08-01 1975-06-03 Cellophane Sa Apparatus for developing a latent charged image
US3918966A (en) * 1972-09-28 1975-11-11 Commw Of Australia Liquid development of an electrical image in which a pulsating field is employed
US3885960A (en) * 1972-12-11 1975-05-27 Bell & Howell Co Method of development of liquid electrostatic images using an hydrophobic barrier liquid
US3951653A (en) * 1973-08-30 1976-04-20 Rank Xerox Ltd. Method of preventing toner build-up on electrodes during liquid development
US5051329A (en) * 1989-12-19 1991-09-24 Dximaging Reversal development of latent electrostatic images on xeroprinting masters
US20070178228A1 (en) * 2006-01-27 2007-08-02 Shiu Hei M Method for fabricating a PCB

Also Published As

Publication number Publication date
DE1597844B2 (de) 1979-05-03
JPS5114030B1 (de) 1976-05-06
DE1597844C3 (de) 1980-01-17
GB1165038A (en) 1969-09-24
DE1597844A1 (de) 1970-12-10
FR1604137A (de) 1971-07-12

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