US3927641A - Developing mechanism using magnetic brush - Google Patents

Developing mechanism using magnetic brush Download PDF

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Publication number
US3927641A
US3927641A US468974A US46897474A US3927641A US 3927641 A US3927641 A US 3927641A US 468974 A US468974 A US 468974A US 46897474 A US46897474 A US 46897474A US 3927641 A US3927641 A US 3927641A
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US
United States
Prior art keywords
potential
magnetic brush
developing
rolls
background
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
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US468974A
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English (en)
Inventor
Kenichi Handa
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 Business Innovation Corp
Original Assignee
Fuji Xerox Co Ltd
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Filing date
Publication date
Application filed by Fuji Xerox Co Ltd filed Critical Fuji Xerox Co Ltd
Application granted granted Critical
Publication of US3927641A publication Critical patent/US3927641A/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
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
    • G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
    • G03G15/09—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer using magnetic brush
    • G03G15/0907—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer using magnetic brush with bias voltage
    • 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
    • G03G13/08—Developing using a solid developer, e.g. powder developer
    • G03G13/09—Developing using a solid developer, e.g. powder developer using magnetic brush

Definitions

  • this magnetic brush developing system usually comprises an electric charging area A, an exposure area B, a developing area C, a transfer area D and a cleaning area E, said areas being arranged successively in that order around a sensitive drum -1.
  • the positive charges are imparted in the charging area A, and the electrostatic latent images corresponding to the light and shade patterns of the original a are formed in the exposure area B.
  • These electrostatic latent images are visualized in the developing area C by a magnetic brush developing device 2, with the thus visualized images being transferred in the transfer area D onto a copying paper delivered from a paper feeder mechanism b, and after completion of the transfer, the surface of the sensitive drum 1 is cleaned in the cleaning area E to get prepared for the next copying cycle.
  • This developing device 2 as shown on an enlarged scale in FIG. 2, comprises a case 3, five pieces of magnetic brush rolls 4, 5, 6, 7 and 8, an adjusting plate 9 and a guide plate 10.
  • the developer d which is composed of colored powdery particles called toner and carrier particles.
  • Each of said magnetic brush rolls 4, 5, 6, 7 and 8 comprises a permanent magnet fixed in the inside of a cylinder having the uneven external surface, whereby said developer d is moved in the direction of arrow F in accordance with rotation of said cylinders.
  • said five pieces of magnetic brush rolls 4, 5, 6, 7 and 8, four of them (5, 6, 7 and 8) which are contacted with the sensitive material 11 on the surface of the sensitive drum 1 are so-called developing magnetic brush rolls or the rolls used exclusively for developing operation, and the first roll 4 alone is used for carrying the developer d adjusted by the adjusting plate 9.
  • the guide plate 10 acts to separate the developer d from the final magnetic brush roll 8 and return it back to the initial position.
  • the development is the operation for visualizing the latent images formed on the sensitive material 11 by contacting the developer d with said sensitive material 11 such that the toner in the developer d will be deposited on the image portions in the latent image section formed on said material 11 but not deposited on the background portions so as to visualize the latent images.
  • a bias voltage V of a value intermediate between the high potential (V,) at the latent images area and the low potential (V at the background.
  • V bias voltage
  • the bias voltage of the magnetic brush rolls must be selected to provided an optimum value by considering the abovesaid two factors.
  • the developing capacity is proportional to the difference (V, V between the potential in the image area on the latent image section and the bias voltage of the magnetic brush rolls and also to the time for which the latent images are exposed to the developer. It is therefore one method for elevating the developing capacity to make arrangement such as to enlarge the value of difference (V V between said image area potential and the bias voltage of the developing magnetic brush rolls by enlarging the difference (V V between the image area potential and the background potential. It is however quite impossible with the presently available techniques to appreciably improve said factors owing to the counteracting properties of the sensitive material and exposure.
  • the number of developing magnetic brush rolls is also increased correspondingly to the increase of speed, thus cancelling the original merit of the magnetic brush type developing system that the developing apparatus can be reduced in size as compared with the cascade type developing system. Further, as the number of developing magnetic brush rolls is increased, the number of spaces other than the developing areas, that is, the spaces (shown by G in FIG.
  • FIG. I is a general schematic view of a known copying apparatus capable of applying to the present invention.
  • FIG. 2 is an enlarged view of the developing mechanism in the apparatus of FIG. 1.
  • Above-said floating toner particles are one of the causes of fouling of the background. All of these toner particles carry electric charges, so that by differentiating the bias voltages applied to the respective developing magnetic brush rolls to provide potential differences between said respective rolls, it is possible to check the toner particles floating in each said space by the action of an electric field present between each adjoining rolls and to thereby reduce deposition of such toner particles on the external surface of the sensitive drum 1.
  • the developing magnetic brush rolls other than said final roll 5 are applied with a bias voltage lower than the background potential to enlarge the difference (V V between the potential at the image section and the bias voltage to the magnetic brush rolls so as to sufficiently elevate the developing capacity at the image section while maintaining the bias voltage of said final developing roll 5 at a value sufficiently higher than the background potential, whereby the toner particles on the peripheral surface of the sensitive drum 1, in the developing area before the final magnetic brush roll 5, can be drawn to said roll 5 to thereby effect cleaning of the background, thus allowing obtainment of a high density image with little soiling of the background.
  • the present invention there are provided more than two developing magnetic brush rolls which are different in applied bias voltage from each other, or the bias voltage applied to the final developing magnetic brush roll is differentiated from that of the other rolls, so that movement of the toner particles floating in the spaces between the adjacent rolls can be checked by dint of the potential difference between the adjoining magnetic brush rolls to minimize deposition of such toner particles on the background other than the image areas on the external surface of the sensitive drum, thereby enabling obtainment of the reproductions with high image density and little soiling in the background.
  • a magnetic brush type developing mechanism having at least two developing magnetic brush rolls, said developing mechanism developing a latent image on a moving recording material with magnetic toner, the improvement comprising means for applying to a first magnetic brush roll encountered by said latent image a first potential, the absolute value of which is substantially greater than the absolute value of the background potential of said latent image and means for applying to a second magnetic brush roll immediately adjacent to said first roll and encountered by said latent image prior to said first roll a second potential, the absolute value of which is less than said absolute value of the background potential whereby development of the image portion of said latent image is enhanced due to the large potential difference between the potential of said image portion and said second potential while background fogging is lessened due to the large potential difference between said first potential and said background potential which attracts the magnetic toner from the space between said first and second magnetic rolls adjacent the recording material.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Magnetic Brush Developing In Electrophotography (AREA)
  • Developing For Electrophotography (AREA)
  • Dry Development In Electrophotography (AREA)
US468974A 1973-05-10 1974-05-10 Developing mechanism using magnetic brush Expired - Lifetime US3927641A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5119973A JPS5510070B2 (nl) 1973-05-10 1973-05-10

Publications (1)

Publication Number Publication Date
US3927641A true US3927641A (en) 1975-12-23

Family

ID=12880207

Family Applications (1)

Application Number Title Priority Date Filing Date
US468974A Expired - Lifetime US3927641A (en) 1973-05-10 1974-05-10 Developing mechanism using magnetic brush

Country Status (4)

Country Link
US (1) US3927641A (nl)
JP (1) JPS5510070B2 (nl)
DE (1) DE2422510C3 (nl)
GB (1) GB1454963A (nl)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4041903A (en) * 1974-05-21 1977-08-16 Konishiroku Photo Industry Co., Ltd. Developing device for use in electrophotography
US4178095A (en) * 1978-04-10 1979-12-11 International Business Machines Corporation Abnormally low reflectance photoconductor sensing system
US4179213A (en) * 1978-04-10 1979-12-18 International Business Machines Corporation Vector pinning in an electrophotographic machine
US4183657A (en) * 1978-04-10 1980-01-15 International Business Machines Corporation Dynamic reference for an image quality control system
US20060051115A1 (en) * 2004-09-07 2006-03-09 Canon Kabushiki Kaisha Image forming apparatus
US8431313B2 (en) 2011-01-31 2013-04-30 Eastman Kodak Company Balancing charge area developed and transferred toner
US8652740B2 (en) 2011-01-31 2014-02-18 Eastman Kodak Company Balancing discharge area developed and transferred toner
US8652741B2 (en) 2011-01-31 2014-02-18 Eastman Kodak Company Enhancement of discharged area developed toner layer
US8676074B2 (en) 2011-03-31 2014-03-18 Eastman Kodak Company Method for providing ratio modulated printing with discharge area development
US8676072B2 (en) 2011-03-31 2014-03-18 Eastman Kodak Company Ratio modulated printing with charge area development
US8693906B2 (en) 2011-03-31 2014-04-08 Eastman Kodak Company Dual toner printing with charge area development
US8693907B2 (en) 2011-03-31 2014-04-08 Eastman Kodak Company Dual toner printing with discharge area development
US8774659B2 (en) 2012-04-24 2014-07-08 Eastman Kodak Company Multi-toner discharged area development method
US8805251B2 (en) 2012-04-24 2014-08-12 Eastman Kodak Company Multi-toner charged area development method
US8805220B2 (en) 2012-04-24 2014-08-12 Eastman Kodak Company Printer with multi-toner discharged area development
US8811864B2 (en) 2012-04-24 2014-08-19 Eastman Kodak Company Printer with multi-toner charged area development

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5814353Y2 (ja) * 1977-03-17 1983-03-22 株式会社リコー 多段磁気ブラシ現像装置
CA1138723A (en) * 1978-07-28 1983-01-04 Tsutomu Toyono Developing method for developer transfer under electrical bias and apparatus therefor
US5194359A (en) * 1978-07-28 1993-03-16 Canon Kabushiki Kaisha Developing method for one component developer
JPS58158657A (ja) * 1982-03-15 1983-09-20 Ricoh Co Ltd 磁気ブラシ現像装置

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3592675A (en) * 1967-10-09 1971-07-13 Azoplate Corp Method for developing latent electrostatic images
US3670700A (en) * 1969-07-03 1972-06-20 Xerox Corp Development electrode
US3674532A (en) * 1970-07-23 1972-07-04 Eastman Kodak Co Control for bias of magnetic brush and method
US3805739A (en) * 1971-06-11 1974-04-23 Xerox Corp Controlling multiple voltage levels for electrostatic printing

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3592675A (en) * 1967-10-09 1971-07-13 Azoplate Corp Method for developing latent electrostatic images
US3670700A (en) * 1969-07-03 1972-06-20 Xerox Corp Development electrode
US3674532A (en) * 1970-07-23 1972-07-04 Eastman Kodak Co Control for bias of magnetic brush and method
US3805739A (en) * 1971-06-11 1974-04-23 Xerox Corp Controlling multiple voltage levels for electrostatic printing

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4041903A (en) * 1974-05-21 1977-08-16 Konishiroku Photo Industry Co., Ltd. Developing device for use in electrophotography
US4178095A (en) * 1978-04-10 1979-12-11 International Business Machines Corporation Abnormally low reflectance photoconductor sensing system
US4179213A (en) * 1978-04-10 1979-12-18 International Business Machines Corporation Vector pinning in an electrophotographic machine
US4183657A (en) * 1978-04-10 1980-01-15 International Business Machines Corporation Dynamic reference for an image quality control system
US20060051115A1 (en) * 2004-09-07 2006-03-09 Canon Kabushiki Kaisha Image forming apparatus
US7260345B2 (en) * 2004-09-07 2007-08-21 Canon Kabushiki Kaisha Image forming apparatus with a developer consumption control feature
US8431313B2 (en) 2011-01-31 2013-04-30 Eastman Kodak Company Balancing charge area developed and transferred toner
US8652740B2 (en) 2011-01-31 2014-02-18 Eastman Kodak Company Balancing discharge area developed and transferred toner
US8652741B2 (en) 2011-01-31 2014-02-18 Eastman Kodak Company Enhancement of discharged area developed toner layer
US8676074B2 (en) 2011-03-31 2014-03-18 Eastman Kodak Company Method for providing ratio modulated printing with discharge area development
US8676072B2 (en) 2011-03-31 2014-03-18 Eastman Kodak Company Ratio modulated printing with charge area development
US8693906B2 (en) 2011-03-31 2014-04-08 Eastman Kodak Company Dual toner printing with charge area development
US8693907B2 (en) 2011-03-31 2014-04-08 Eastman Kodak Company Dual toner printing with discharge area development
US8774659B2 (en) 2012-04-24 2014-07-08 Eastman Kodak Company Multi-toner discharged area development method
US8805251B2 (en) 2012-04-24 2014-08-12 Eastman Kodak Company Multi-toner charged area development method
US8805220B2 (en) 2012-04-24 2014-08-12 Eastman Kodak Company Printer with multi-toner discharged area development
US8811864B2 (en) 2012-04-24 2014-08-19 Eastman Kodak Company Printer with multi-toner charged area development

Also Published As

Publication number Publication date
DE2422510B2 (de) 1977-03-10
GB1454963A (en) 1976-11-10
DE2422510A1 (de) 1974-11-28
JPS5510070B2 (nl) 1980-03-13
JPS503344A (nl) 1975-01-14
DE2422510C3 (de) 1980-01-31

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