US3854449A - Development apparatus - Google Patents

Development apparatus Download PDF

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Publication number
US3854449A
US3854449A US00255259A US25525972A US3854449A US 3854449 A US3854449 A US 3854449A US 00255259 A US00255259 A US 00255259A US 25525972 A US25525972 A US 25525972A US 3854449 A US3854449 A US 3854449A
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United States
Prior art keywords
developer
latent image
housing
advancing
tubular member
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
US00255259A
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English (en)
Inventor
J Davidson
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.)
Xerox Corp
Original Assignee
Xerox Corp
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 Xerox Corp filed Critical Xerox Corp
Priority to US00255259A priority Critical patent/US3854449A/en
Priority to CA155,249A priority patent/CA982886A/en
Priority to SU721851101A priority patent/SU677684A3/ru
Priority to BR8398/72A priority patent/BR7208398D0/pt
Priority to AR245462A priority patent/AR195893A1/es
Priority to FR7243003A priority patent/FR2186147A5/fr
Priority to DE2261023A priority patent/DE2261023C3/de
Priority to CH1854672A priority patent/CH551030A/xx
Priority to BE129367A priority patent/BE797447A/xx
Priority to FI1625/73A priority patent/FI59493C/fi
Priority to AU55903/73A priority patent/AU5590373A/en
Priority to ES414905A priority patent/ES414905A1/es
Priority to IT24361/73A priority patent/IT987768B/it
Priority to SE7307101A priority patent/SE382695B/xx
Priority to ZA733407A priority patent/ZA733407B/xx
Priority to NL7307084A priority patent/NL7307084A/xx
Priority to GB5110375A priority patent/GB1435763A/en
Priority to JP5710973A priority patent/JPS553707B2/ja
Priority to GB2434273A priority patent/GB1435761A/en
Priority to US430867A priority patent/US3906897A/en
Priority to US05/430,868 priority patent/US3940272A/en
Application granted granted Critical
Publication of US3854449A publication Critical patent/US3854449A/en
Anticipated expiration legal-status Critical
Expired - Lifetime 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
    • 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

Definitions

  • This invention relates generally to an electrostatographic printing machine, and more particularly concerns an improved development system for use therein.
  • An electrostatographic process involves the formation and utilization of electrostatic latent charge patterns for the purpose of recording and reproducing the patterns in viewable form.
  • the field of electrostatography includes electrophotography and electrography.
  • Electrophotography is that class of electrostatography which employs aphotosensitive medium to form, with the aid of electromagnetic radiation, the electrostatic latent charge pattern.
  • Xerography which employs infrared, visible or ultraviolet radiation
  • xeroradiography which employs X-rays of gamma rays, are sub-classes of electrophotography.
  • Electrography is that class of electrostatography which utilizes an insulating medium to form, without the aid of electromagnetic radiation, the electrostatic latent charge pattern.
  • Xero printing which uses a pattern of insulating material on a conductive medium to form electrostatic charge patterns
  • electrographic recording which uses a charge transfer between a plurality of electrodes to form directly, electrostatic charge patterns
  • Development which is the act of rendering an electrostatic pattern or image viewable, is employed in all of the aforementioned classes of electrostatography. In the illustrated embodiment hereinafter discussed, an electrophotographic process is utilized.
  • An electrophotographic process involves the use of a photosensitive element having a photoconductive insulating layer which is charged to a substantially uniform potential in order to sensitize its surface.
  • the charged photoconductive surface is exposed to a light image of an original document to be reproduced.
  • the charge is selectively dissipated in the irradiated areas in accordance with the light intensity reaching the surface, thereby creating an electrostatic latent image on the photoconductive surface.
  • Development of the electrostatic latent image recorded on the photoconductive surface is achieved by bringing the charged photoconductive surface into contact with a developer mix.
  • Typical developer mixes employed are well-known in the art, and generally comprise dyed or colored thermoplastic powders, known in the art as toner particles, which are mixed with coarser carrier granules, such as ferromagnetic granules.
  • the toner particles and carrier granules are selected such that the toner particles acquire the appropriate charge relative to the electrostatic latent image recorded on the photoconductive surface.
  • the greater attractive force of the latent electrostatic image recorded thereon causes the toner particles to transfer from the carrier granules and adhere to the latent electrostatic image.
  • Magnetic brush systems usually include a developer roll having a directional flux field adapted to bring the magnetizable developer mix into contact with the charged photoconductive surface.
  • Multi-color electrostatographic printing involves the utilization of various processing components adapted to produce a series of electrostatic latent images corresponding to a particular color of the original. In such a system, there is a need to develop successive partial color images. Each partial color image is developed with toner particles corresponding in color to the partial color image utilized to form the respective electrostatic latent image on the photoconductive surface.
  • a multi-color development system utilizes a plurality of developer rolls, each being adapted to furnish the appropriate colored toner particles to the photoconductive surface.
  • fixedly mounted developer rolls were closely spaced to the photoconductive surface, thereby permitting the operative developer roll, i.e., the developer roll having the developer mix adhering thereto, to deposit toner particles on the photoconductive surface.
  • the operative developer roll i.e., the developer roll having the developer mix adhering thereto
  • an apparatus for rendering visible a latent electrostatic image The apparatus is positioned adjacent the latent image in operative communication therewith for depositing toner particles thereon. In addition, the apparatus moves from the operative position in communication with the latent image to an inoperative position spaced therefrom.
  • the present invention is also concerned with actuating the development apparatus in response to the electrostatic latent image advancing to a pre-determined location.
  • the apparatus is energized when the latent image reaches the pre-determined location to move to a position adjacent thereto in operative communication therewith, and deposits toner particles thereon. After the toner particles are deposited onto the latent image, the apparatus is de-energized and moved to its inoperative position spaced from the latent image.
  • FIG. 1 is a schematic perspective view of an electrophotographic printing machine embodying the features of the present invention
  • FIG. 2 is a sectional elevational view of the development system of the present invention used in the printing machine illustrated in FIG. 1;
  • FIG. 3 isa fragmentary sectional elevational view depicting, in detail, one of the development units shown in FIG. 2.
  • FIG. 1 schematically illustrates the various components of a printing machine producing multi-color copies from a color original.
  • a light image of a document to be reproduced is projected onto a sensitized photoconductive surface to form an electrostatic latent image thereon.
  • the latent image is developed by toner particles to form a powder image of the latent image recorded on the. photoconductive surface.
  • the powder image is electrostatically transferred to a sheet of support material to which it may be coalesced by a suitable fusing device, whereby the powder image is caused permanently to adhere to the support surface.
  • the printing machine depicted in FIG. 1 employs a photoconductive member, such as rotatably mounted drum 10, having a photoconductive surface 12 thereon.
  • Photoconductive surface 12 preferably, is formed of a material having a relatively panchromatic response to white light.
  • Drum rotates in the direction indicated by arrow 14 to move photoconductive surface 12 sequentially through a series of processing stations.
  • photoconductive surface 12 passes through charging station A which has positioned thereat a corona generating device, indicated generally at 16, ex-.-
  • Corona generating device 16 charges drum surface 12 to a relatively high and substantially uniform potential.
  • the charged durm surface is next rotated to exposure station B which includes a moving lens system, generally designated by the reference numeral 18, and a color filter mechanism, shown generally at 20.
  • An original document 22 is stationarily supported upon a transparent viewing platen 24 wherein successive incremental areas of original 22 are illuminated by means of a moving lamp assembly 26.
  • Lens system 18 is adapted to scan successive areas of original 22 being illuminated on platen 24 and to focus the light onto photoconductive surface 12. Lamp assembly 26 and lens system 18 are moved in timed relation with photoconductive surface 12 to produce a non-distorted flowing light image of the original on photoconductive surface 12.
  • filter mechanism 20 interposes selected color filters into the optical light path of lens 18.
  • Color filters 20 operate on the light passing through lens 18 to record an electrostatic latent image on photoconductive surface 12 corresponding to a specific color of the following light image of the original.
  • drum ]0 is rotated to development station C which includes three individual development units generally indicated by the reference numerals 28, 30 and 32, respectively.
  • the development units are all of a type hereinbefore referred to as magnetic brush development system.
  • a magnetizable developer mix having carrier granules and toner particles is continually brought through a directional flux field to form a brush of developer material.
  • the developer mix is continually moving to provide fresh developer mix to the brush.
  • the brush in the magnetic brush system comprises a magnetic member with a mass of developer mix adhered thereto by magnetic attraction.
  • the developer mix includes carrier granules having toner particles clinging thereto by triboelectric attraction.
  • This chainlike arrangement of developer mix simulates the fibers ofa brush. Development is achieved by bringing the brush of developer mix into contact with photoconductive surface 12.
  • Each of the development units 28, 30 and 32 respectively, apply toner particles to photoconductive surface 12 which are adapted to absorb light within a pre-selected spectral region of the electromagnetic wave spectrum corresponding to the wavelength of light transmitted through the filter. For example, a latent image formed by passing the light image through a green filter will record the red and blue portions of the spectrum as areas of relatively high charge density on photoconductive surface 12, while the green light rays will pass through the filter and cause the charge density on photoconductive surface 12 to be reduced to a voltage level ineffective for development.
  • the charged areas are then made visible by applying green absorbing (magenta) toner particles to the latent image recorded on photoconductive surface 12. Similarly a blue separation is developed with blue absorbing (yellow) toner particles, while a red separation is developed with red absorbing (cyan) toner particles.
  • transfer station D After development, the now visible image is moved to transfer station D where the image is transferred to a sheet of final support material 36, such as plain paper amongst others, by means of a transfer member, i.e., a bias transfer roll shown generally at 34.
  • the surface of transfer roll 34 is electrically biased to a potential havface 12 to support sheet 36.
  • Transfer roll 34 is adapted to secure releasably thereto a single sheet of final support material 36 for movement in a recirculating path, the roll being arranged to move in synchronism with photoconductive surface 12 enabling support material 36 to receive, in superimposed registration, successive toner powder images of the original document.
  • the aforementioned steps of charging the photoconductive surface, exposing the photoconductive surface to a specific color of the flowinglight image of the original, developing the electrostatic latent image recorded on the photoconductive surface with appropriate toner particles, and transferring the toner powder image to a sheet of final support material, e.g., a transparency or opaque copy sheet, are repeated a plurality of cycles to form a multi-color copy of a color original.
  • support sheet 36 is stripped from roll 34 and transported on endless belt 50 to a fixing station F where a fuser, indicated generally at 38, coalesces the toner powder image to support sheet 36. Thereafter, sheet 36 is advanced by endless belts 52 and 54 to catch tray 40 for subsequent removal by an operator.
  • the last processing station in the direction of rotation of drum 10, as indicated by arrow 14, is cleaning station E.
  • a rotatably mounted fibrous brush 56 is positioned in cleaning station E and is maintained in contact with photoconductive surface 12 of rotating drum to remove residual toner particles remaining thereon after each transfer operation.
  • FIG. 2 there is shown in multicolor development system with frame 27 supporting three toner depositing means or development units 28, 30 and 32, respectively.
  • the aforementioned development system is of the type utilized at processing station C.
  • These'development units are depicted in an elevational sectional view to indicate more clearly the various components included therein.
  • Only development unit 28 will be described in detail as development units 30 and 32 are nearly identical thereto, the distinction between each developer unit being the color of toner particles contained therein and minor geometrical differences due to the mounting cycle.
  • Developer unit 28 may have yellow toner particles, unit 30 magenta toner particles, and unit 32 cyan toner particles although different color combinations may be used.
  • development unit 28 will be hereinafter described in detail.
  • developer unit 28 The principle components of developer unit 28 are a developer housing 42, conveyor means or paddle wheel 44, transport means or roll 46, and developer means or roll 48.
  • Paddle wheel 44 is a cylindrical member with buckets or scoops around the periphery thereof and is adapted to rotate so as to elevate developer mix 50 from the lower region of housing 42 to the upper region thereof. When developer mix 50 reaches the upper region of housing 42, it is lifted from the paddle wheel buckets to transport roll 46. Alternate buckets of the paddle wheel have apertures in the root diameter so that developer mix carried in these areas is not carried to transport roll 46 but instead, falls back to the lower region of developer housing 42.
  • developer mix 50 As the developer mix falls back to the lower region of developer housing 42, it cascades over shroud 62 which is of a tubular configuration with an aperture 53 in the lower region thereof. Developer mix 50 is recirculated in this manner so that the carrier granules are continually agitated to mix with fresh toner particles. This generates a strong triboelectric charge between the carrier granules and toner particles. As developer mix 50, in the paddle wheel buckets, approaches transport roll 46, the magnetic fields produced by the fixed magnets therein attract developer mix 50. Transport roll 46 moves developer mix 50 in an upwardly direction by the frictional force exerted between the roll surface and developer mix.
  • a surplus of developer mix 50 is furnished, and metering blade 58 is provided to control the amount of developer mix 50 carried over the top of transport roll 46.
  • the surplus developer mix 50 is sheared from transport roll 46 and falls in a downwardly direction toward paddle wheel 44. As the surplus developer mix descends, it falls through the apertures of paddle wheel 44 in a downwardly direction into the lower region of developer housing 42.
  • the developer mix which passes metering blade 58 is carried over transport roll 46 to developer roll 48 and into development zone 49 located between photoconductive surface 12 and developer roll 48.
  • the electrostatic image recorded on the photoconductive surface is developed by contact with the moving developer mix 50.
  • the charged areas of photoconductive surface 12 electrostatically attract the toner particles from the carrier granules of developer mix 50.
  • the strong magnetic fields in a direction generally tangential to developer roll 48 continues to secure thereto the unused developer mix and denuded carrier granules.
  • the unused developer mix and denuded carrier granules Upon passing from the development zone, the unused developer mix and denuded carrier granules enter a region relatively free from magnetic forces and fall from developer roll 48 in a downwardly direction into the lower region of developer housing 42.
  • mixing baffle 60 diverts the flow from the ends towards the center of developer housing 42 to provide mixing in this direction.
  • Cylindrical shroud 62 serves to control the fall of the unused developer mix and denuded carrier granules such that they mix with the toner particles rather than simply falling into the lower region of developer housing 42. Furthermore, shroud 62 isolates, from the developer mix, an interior cylindrical enclosure which is used to house cylindrical toner dispenser 64. Toner dispenser 64 contains a fresh supply of toner 51 which is dropped through aperture 53 in the shroud into the stream of developer mix 50. Adding toner particles at this location ensures that it cannot be carried into development zone 49 without some degree of mixing with the carrier granules. Additional toner particles are added to the developer mix in order to replace the toner particles used in forming powder images, thereby maintaining the concentration thereof substantially constant, providing uniform color image developability.
  • development unit 28 initially positions developer roll 48 adjacent photoconductive surface 12 in operative communication therewith to develop the first partial color latent electrostatic image formed thereon with the appropriately colored toner particles. Thereafter, the toner particles are transferred to support material 36 (FIG. 1) forming a toner powder image of one color of the multi-color original.
  • development unit 32 positions its respective developer roll adjacent photoconductive surface 12 in operative communication therewith to develop the next successive colored image which, in turn, is transferred to support material 36.
  • development unit 30 is positioned adjacent photoconductive surface 12 in operative communication therewith to develop the next successive colored image.
  • This toner powder image is also transferred to support material 36 forming a composite multi-color toner powder image of the original on the support material which is thereafter coalesced in fuser 38 (FIG. 1).
  • developer means or roll 48 includes a nonmagnetic tubular member 70, preferably made from aluminum having an irregular or roughened exterior surface. Tubular member is journaled for rotation by suitable means such as ball bearing mounts.
  • a shaft 72 made preferably of steel is concentrically mounted within tubular member 70 and serves as a fixed mounting for magnetic means 74.
  • Magnetic means 74 preferably, comprises magnets made of barrium ferrite in the form of annular rings and arranged with five poles on about a 284 are about shaft 72.
  • transport means or roll 46 includes a non-magnetic tubular member 76, preferably, made from aluminum having an irregular or roughened exterior surface.
  • Tubular member 76 is journaled for rotation by suitable means such as ball bearing mounts.
  • a shaft 78 made, preferably, of steel is concentrically mounted within tubular member 76 and functions as a fixed mounting for magnetic means 80.
  • Magnetic means 80 preferably, includes barrium ferrite magnets in the form of annular rings arranged with four poles on a are about shaft 78.
  • the means for actuating each of the toner depositing means or development units 28, 30 and 32, respectively, is a timing disc mounted to an extension of drum shaft 11 (FIG. 1).
  • the timing disc is opaque with a plurality of spaced slots in the circumferential periphery thereof.
  • the timing disc is interposed between an illuminating source and a photosensor to generate an electrical signal as each slot permits light rays to pass through the disc.
  • the electrical signal in association with a suitable machine logic control system, activates the appropriate development unit.
  • Activation of the development unit energizes the drive motor which rotates the paddle wheel, transport roll and developer roll producing a reaction torque which overcomes the spring restraining force, wherein the developer roll is moved into operative communication with the photoconductive surface.
  • a slot in the timing disc permits the light rays from'the illumination source to once again cause the photosenser to generate a second electric signal, which, in association with the machine control logic, de-activates the development unit by de-energizing the driving motor. Inactivation of the development unit automatically causes the development unit to be moved to the inoperative position, wherein the developer roll is spaced from the photoconductive surface.
  • fur brush development brush fibers replace carrier granules, and when the brush is saturated with toner particles the toner particles become charged triboelectrically.
  • a soft fur is used in the form of a cylindrical brush. Toner particles are fed continuously to the brush and when activated moves from its inoperative position spaced from the photoconductive surface to its operative position in communication therewith.
  • developing system of the present invention improves multi-color copies produced on an electrostatic printing machine by maintaining inoperative development units spaced from the photoconductive surface. Furthermore, the development system is designed to move the appropriate development unit into operative communication withthe photoconductive surface for transferring thereto appropriately colored toner particles to render visible the electrostatic latent image recorded thereon.
  • An apparatus for rendering visible an electrostatic latent image including:
  • a housing having a chamber therein for storing particles
  • An apparatus for rendering visible an electrostatic latent image including:
  • a developer housing defining a chamber storing a developermix comprising carrier granules and toner particles;
  • rotary driven developer means mounted within the chamber of said developer housing closely proximate to said advancing means for receiving the developer mix therefrom, and arranged to deposit toner particles onto the latent image when in operative communication therewith;
  • conveyor means mounted for movement within the chamber of said developer housing, and arranged to move the developer mix from a first region to an intermediate region;
  • rotary driven transport means mounted within the chamber of said developer housing, and arranged to move the developer mix from the intermediate region to the second region for discharge thereat.
  • said transport means includes a first tubular member of nommagnetic material, said first magnetic means fixedly disposed within said first tubular member for creating a magnetic field in the path of the periphery of said first tubular member;
  • said developer means includes a second tubular member of non-magnetic material, and second magnetic means fixedly disposed within said second tubular member for creating a magnetic field in the path of the periphery of said second tubular member.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Dry Development In Electrophotography (AREA)
  • Magnetic Brush Developing In Electrophotography (AREA)
  • Color Electrophotography (AREA)
US00255259A 1972-05-22 1972-05-22 Development apparatus Expired - Lifetime US3854449A (en)

Priority Applications (21)

Application Number Priority Date Filing Date Title
US00255259A US3854449A (en) 1972-05-22 1972-05-22 Development apparatus
CA155,249A CA982886A (en) 1972-05-22 1972-10-31 Development apparatus
SU721851101A SU677684A3 (ru) 1972-05-22 1972-11-29 Устройство дл про влени цветного изображени в электрографическом аппарате
BR8398/72A BR7208398D0 (pt) 1972-05-22 1972-11-29 Aparelho e processo para tornar visivel uma imagem eletrostatica latente, e maquina de impressao eletrofotografica aperfeicoada
AR245462A AR195893A1 (es) 1972-05-22 1972-12-02 Aparato para hacer visible una imagen latente electrostatica
FR7243003A FR2186147A5 (da) 1972-05-22 1972-12-04
DE2261023A DE2261023C3 (de) 1972-05-22 1972-12-13 Entwicklungsvorrichtung für latente elektrostatische Bilder und elektrophotographische Kopiermaschine mit einer solchen Vorrichtung
CH1854672A CH551030A (de) 1972-05-22 1972-12-20 Verfahren und vorrichtung zum entwickeln eines latenten elektrostatischen bildes.
BE129367A BE797447A (fr) 1972-05-22 1973-03-28 Dispositif de developpement pour machine d'impression ou de reproduction electrographique
ES414905A ES414905A1 (es) 1972-05-22 1973-05-18 Un metodo y su correspondiente aparato para hacer visible una imagen latente electrostatica.
FI1625/73A FI59493C (fi) 1972-05-22 1973-05-18 Foerfarande och apparat foer framkallning av en elektrostatisk latent bild
AU55903/73A AU5590373A (en) 1972-05-22 1973-05-18 Development apparatus development apparatus
SE7307101A SE382695B (sv) 1972-05-22 1973-05-21 Forfarande och anordning for framkallning av en elektrostatisk latent bild.
ZA733407A ZA733407B (en) 1972-05-22 1973-05-21 Development apparatus
NL7307084A NL7307084A (da) 1972-05-22 1973-05-21
IT24361/73A IT987768B (it) 1972-05-22 1973-05-21 Apparecchiatura per rendere visi bile un immagine elettrostatica latente
GB5110375A GB1435763A (en) 1972-05-22 1973-05-22 Electrostatic image development apparatus
JP5710973A JPS553707B2 (da) 1972-05-22 1973-05-22
GB2434273A GB1435761A (en) 1972-05-22 1973-05-22 Electrostatic image development apparatus
US430867A US3906897A (en) 1972-05-22 1974-01-04 Development apparatus
US05/430,868 US3940272A (en) 1972-05-22 1974-01-04 Method of developing an electrostatic latent image

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00255259A US3854449A (en) 1972-05-22 1972-05-22 Development apparatus

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US05/430,868 Division US3940272A (en) 1972-05-22 1974-01-04 Method of developing an electrostatic latent image

Publications (1)

Publication Number Publication Date
US3854449A true US3854449A (en) 1974-12-17

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US00255259A Expired - Lifetime US3854449A (en) 1972-05-22 1972-05-22 Development apparatus

Country Status (18)

Country Link
US (1) US3854449A (da)
JP (1) JPS553707B2 (da)
AR (1) AR195893A1 (da)
AU (1) AU5590373A (da)
BE (1) BE797447A (da)
BR (1) BR7208398D0 (da)
CA (1) CA982886A (da)
CH (1) CH551030A (da)
DE (1) DE2261023C3 (da)
ES (1) ES414905A1 (da)
FI (1) FI59493C (da)
FR (1) FR2186147A5 (da)
GB (2) GB1435761A (da)
IT (1) IT987768B (da)
NL (1) NL7307084A (da)
SE (1) SE382695B (da)
SU (1) SU677684A3 (da)
ZA (1) ZA733407B (da)

Cited By (21)

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Publication number Priority date Publication date Assignee Title
US3926516A (en) * 1974-02-20 1975-12-16 Xerox Corp Development apparatus for an electrostatographic printing machine
US3941084A (en) * 1973-11-27 1976-03-02 Minolta Camera Kabushiki Kaisha Automatic toner supplying device
US3948217A (en) * 1974-11-20 1976-04-06 Xerox Corporation Magnetic brush development system with floating development rolls
US3953121A (en) * 1974-10-29 1976-04-27 Xerox Corporation Articulated development apparatus
US3965862A (en) * 1975-01-30 1976-06-29 Xerox Corporation Xerographic development system
US3970042A (en) * 1975-01-17 1976-07-20 Xerox Corporation Color development apparatus
FR2299669A1 (fr) * 1975-02-03 1976-08-27 Xerox Corp Donneur xerographique a micro-champs et procede pour transporter des particules de toner chargees
US3987756A (en) * 1974-07-19 1976-10-26 Canon Kabushiki Kaisha Developing device
US3998184A (en) * 1975-03-20 1976-12-21 Xerox Corporation Development apparatus
US4034701A (en) * 1972-06-28 1977-07-12 Xerox Corporation Particle dispenser
US4043293A (en) * 1976-05-03 1977-08-23 Xerox Corporation Developability regulating apparatus
FR2339876A1 (fr) * 1976-02-02 1977-08-26 Xerox Corp Procede et dispositif de balayage d'un luminescent par un faisceau laser pour la reproduction de documents en couleurs
US4068939A (en) * 1975-01-13 1978-01-17 Xerox Corporation Color transparency reproducing machine
US4143961A (en) * 1974-04-15 1979-03-13 Hiroo Nakamoto Electrophotographic duplication apparatus
US4352552A (en) * 1980-06-25 1982-10-05 Xerox Corporation Multicolor development system for electrophotographic printing machines
US4602862A (en) * 1984-11-16 1986-07-29 Xerox Corporation Valve for a multi-color development system
US4801966A (en) * 1985-04-06 1989-01-31 Canon Kabushiki Kaisha Image forming apparatus with movable developing device
US4891674A (en) * 1988-06-09 1990-01-02 Xerox Corporation Retractable development apparatus
US4896193A (en) * 1985-11-15 1990-01-23 Canon Kabushiki Kaisha Multicolored image forming apparatus separable for ease of maintenance
US5066981A (en) * 1990-10-15 1991-11-19 Eastman Kodak Company Mechanism for responsively spacing a development roller
US6473586B2 (en) 2001-03-02 2002-10-29 Fuji Xerox Co., Ltd. Developing unit and image forming apparatus using the same

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Publication number Priority date Publication date Assignee Title
JPS578031Y2 (da) * 1975-12-15 1982-02-16
JPS536652U (da) * 1976-07-02 1978-01-20
JPS53159332U (da) * 1977-05-20 1978-12-13
JPS557726A (en) * 1978-06-30 1980-01-19 Konishiroku Photo Ind Co Ltd Image forming method and image forming device
US4267201A (en) * 1978-10-20 1981-05-12 Ricoh Company, Ltd. Magnetic brush development apparatus and method
JPS5536889A (en) * 1979-01-24 1980-03-14 Ricoh Co Ltd Dichromatic image reproduction method
JPS58133156U (ja) * 1982-03-03 1983-09-08 コニカ株式会社 現像装置
JPS6086561A (ja) * 1983-10-18 1985-05-16 Toshiba Corp 画像形成装置
JPS60250369A (ja) * 1984-05-28 1985-12-11 Konishiroku Photo Ind Co Ltd 画像形成装置
JPS61129665A (ja) * 1984-11-29 1986-06-17 Canon Inc 現像装置
US4710016B1 (en) * 1985-03-26 1997-02-25 Toshiba Kk Developing apparatus
US4679928A (en) * 1985-06-13 1987-07-14 Xerox Corporation Development apparatus
JPS6292825U (da) * 1985-11-30 1987-06-13
JPH0746249B2 (ja) * 1986-06-09 1995-05-17 キヤノン株式会社 画像形成装置

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US3609029A (en) * 1969-11-14 1971-09-28 Xerox Corp Materials application apparatus
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Cited By (23)

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US4034701A (en) * 1972-06-28 1977-07-12 Xerox Corporation Particle dispenser
US3941084A (en) * 1973-11-27 1976-03-02 Minolta Camera Kabushiki Kaisha Automatic toner supplying device
US3926516A (en) * 1974-02-20 1975-12-16 Xerox Corp Development apparatus for an electrostatographic printing machine
US4143961A (en) * 1974-04-15 1979-03-13 Hiroo Nakamoto Electrophotographic duplication apparatus
US3987756A (en) * 1974-07-19 1976-10-26 Canon Kabushiki Kaisha Developing device
US3953121A (en) * 1974-10-29 1976-04-27 Xerox Corporation Articulated development apparatus
US3948217A (en) * 1974-11-20 1976-04-06 Xerox Corporation Magnetic brush development system with floating development rolls
FR2292267A1 (fr) * 1974-11-20 1976-06-18 Xerox Corp Dispositif de developpement a brosse magnetique a rouleaux de developpement flottants
US4068939A (en) * 1975-01-13 1978-01-17 Xerox Corporation Color transparency reproducing machine
US3970042A (en) * 1975-01-17 1976-07-20 Xerox Corporation Color development apparatus
US3965862A (en) * 1975-01-30 1976-06-29 Xerox Corporation Xerographic development system
FR2299669A1 (fr) * 1975-02-03 1976-08-27 Xerox Corp Donneur xerographique a micro-champs et procede pour transporter des particules de toner chargees
US3998184A (en) * 1975-03-20 1976-12-21 Xerox Corporation Development apparatus
FR2339876A1 (fr) * 1976-02-02 1977-08-26 Xerox Corp Procede et dispositif de balayage d'un luminescent par un faisceau laser pour la reproduction de documents en couleurs
US4043293A (en) * 1976-05-03 1977-08-23 Xerox Corporation Developability regulating apparatus
US4352552A (en) * 1980-06-25 1982-10-05 Xerox Corporation Multicolor development system for electrophotographic printing machines
US4602862A (en) * 1984-11-16 1986-07-29 Xerox Corporation Valve for a multi-color development system
US4801966A (en) * 1985-04-06 1989-01-31 Canon Kabushiki Kaisha Image forming apparatus with movable developing device
US4896193A (en) * 1985-11-15 1990-01-23 Canon Kabushiki Kaisha Multicolored image forming apparatus separable for ease of maintenance
US4891674A (en) * 1988-06-09 1990-01-02 Xerox Corporation Retractable development apparatus
US5066981A (en) * 1990-10-15 1991-11-19 Eastman Kodak Company Mechanism for responsively spacing a development roller
WO1992007306A1 (en) * 1990-10-15 1992-04-30 Eastman Kodak Company Mechanism for responsively spacing a development roller
US6473586B2 (en) 2001-03-02 2002-10-29 Fuji Xerox Co., Ltd. Developing unit and image forming apparatus using the same

Also Published As

Publication number Publication date
CH551030A (de) 1974-06-28
BE797447A (fr) 1973-09-28
ES414905A1 (es) 1976-05-16
NL7307084A (da) 1973-11-26
FR2186147A5 (da) 1974-01-04
ZA733407B (en) 1974-04-24
JPS4951953A (da) 1974-05-20
JPS553707B2 (da) 1980-01-26
BR7208398D0 (pt) 1974-07-25
CA982886A (en) 1976-02-03
AU5590373A (en) 1974-11-21
DE2261023A1 (de) 1973-12-06
FI59493B (fi) 1981-04-30
FI59493C (fi) 1981-08-10
AR195893A1 (es) 1973-11-15
GB1435761A (en) 1976-05-12
IT987768B (it) 1975-03-20
SE382695B (sv) 1976-02-09
SU677684A3 (ru) 1979-07-30
DE2261023C3 (de) 1981-01-22
GB1435763A (en) 1976-05-12
DE2261023B2 (de) 1980-05-14

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