US3759222A - Microfield donor with continuously reversing microfields - Google Patents

Microfield donor with continuously reversing microfields Download PDF

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Publication number
US3759222A
US3759222A US00121090A US3759222DA US3759222A US 3759222 A US3759222 A US 3759222A US 00121090 A US00121090 A US 00121090A US 3759222D A US3759222D A US 3759222DA US 3759222 A US3759222 A US 3759222A
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United States
Prior art keywords
microfields
toner particles
toner
electrode
donor
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Expired - Lifetime
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US00121090A
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English (en)
Inventor
J Maksymiak
R Lewis
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Xerox Corp
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Xerox Corp
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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
    • G03G15/0806—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer on a donor element, e.g. belt, roller
    • G03G15/0818—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer on a donor element, e.g. belt, roller characterised by the structure of the donor member, e.g. surface properties

Definitions

  • This method and apparatus relates to development of electrostatic latent images and more particularly to more effective use of a microfield donor member for long-term use in presenting toner particles to a latent image for development thereof.
  • a photoconductive surface is charged and then exposed to a light pattern of the information to be recorded or reproduced, thereby forming an electrostatic latent image on the photoconductive surface.
  • Toner particles which may be finely divided, pigmented, resinous material, are presented to the latent image where they are attracted to the photoconductive surface.
  • the toner image can be fixed and made permanent on the photoconductive surface or it can be transferred to another surface where it is fixed.
  • Transfer development broadly involves bringing a layer of toner to an imaged photoconductor where toner particles will be transferred from the layer to the imaged areas.
  • the term transfer development is generic to development techniques where (1) the toner layer is out of contact with the imaged photoconductor and the toner particles must traverse an air gap to effect development, (2) the toner layer is brought into rolling contact with the imaged photoconductor to effect development, and (3) the toner layer is brought into contact with the imaged photoconductor and skidded across the imaged surface to effect development. Transfer development has also come to be known as touchdown development".
  • a cylindrical or endless donor member is rotated so that its surface can be presented to the moving surface of a photoconductive drum bearing an electrostatic latent image thereon.
  • processing stations Positioned about the periphery of the donor member are processing stations which may include some or all of the following: a donor loading station, at which toner is made to adhere to the donor member surface; an agglomerate removal station at which toner agglomerates are removed from the retained toner layer; a charging station at which a uniform charge is placed on the retained toner; a cleanup station at which the retained toner layer is converted into one of uniform-thickness and any remaining agglomerates are removed from the retained toner layer; a development station at which the retained toner is presented to the imaged photoconductor for image development; and a cleaning station at which a neutralizing charge is placed upon the residual toner particles and at which a cleaning member removes residual toner from the peripheral surface of the donor. In this manner, a more or less continuous development process is carried out.
  • Such a donor includes, an electrically conductive support member in the form of a cylinder, a thin electrically insulating layer overlying the support member, and'a continuous, electrically conductive screen pattern overlying the insulating layer.
  • a protective dielectric layer may be flush with or just cover the conductive screen pattern.
  • a potential difference between the conductive screen pattern and the conductive substrate creates fringe fields or microfields which extend into the air region beyond the outer surface of the donor member. It is the extended portion of these microfields which attract and hold the toner particles to the surface of the donor member for subsequent presentation to the imaged photoconductor.
  • Still another object of the invention is to improve upon transfer development processes.
  • Yet another object is to improve upon microfield donor loading techniques by providing for continuously effective microfields.
  • the conductivity of the outer dielectric region just beyond the inner dielectric film separating the screen electrode from the conductive substrate i.e., the air dielectric or a second dielectric film
  • the interface between these dielectrics tends to approach or equal the potential of the voltage source.
  • no fine structured microfield will exist beyond this interface and effective toner attraction will be lost.
  • the time it takes for this condition to develop can be termed the equilibrium time. Details of the equilibrium field structure depend upon the relative conductivities of the dielectrics involved. Even if the inner dielectric and the outer dielectric were of the same material, conditions such as humidity or toner contamination would make the layers sufficiently electrically different that an equilibrium condition would rapidly occur, destroying the effectiveness of the microfields.
  • microfield nulling effects may be controlled by periodically reversing the direction of the microfields involved by switching the polarity of the voltage source. Charges distributed or accrued within the dielectric and at the dielectric interfaces in the structure are then periodically removed if the time between polarity reversals is appreciably smaller than the equilibrium time.
  • the present invention is directed to a developing method for electrostatic latent images formed on the surface of an image-retaining member.
  • the treating stations include: a toner loading station, having a supply of toner particles at which a layer of toner particles becomes adhered to the surface of the donor member; and a development station, at which the toner particles carried by the donor member are presented in developing relation to the latent image.
  • the donor member comprises a dielectric layer separating a conductive screen pattern electrode from a conductive continuous film electrode.
  • one electrode is maintainted at a reference potential and the other is maintained at a sufficiently different potential so as to create microfields extending into the region beyond the surface of the donor member to attract to and hold toner particles on the surface of the donor member carrying the screen electrode.
  • a reversal in the direction of the microfields After the donor has been loaded with toner particles, a reversal in the direction of the microfields.
  • the donor member comprises an endless dielectric layer separating a continuous, electrically conductive screen pattern electrode from a plurality of mutually electrically isolated conductive film electrodes.
  • a potential difference is maintained between each film electrode and the screen electrode sufficient to create microfields extending into the region beyond the surface of the donor member to attract to and hold toner particles on the surface of the donor member carrying the screen electrode.
  • a field reversal in the direction of the microfields between each film electrode and the screen electrode is sequentially effected for a sufficient time and at a sufficient potential to remove charges from the dielectric layer accrued during the time period of toner loading. Thereafter the fields are sequentially returned to their former direction prior to again bringing each film electrode region of the donor member to the toner loading station.
  • the invention is also directed to an apparatus for developing an electrostatic latent image formed on the surface of an image-retaining member.
  • the apparatus includes a means for developing the latent image, said means including: (a) a microfield donor member adapted to transport toner particles to the latent image, said donor member comprising, a dielectric layer separating a conductive screen pattern electrode from a conductive continuous film electrode: (b) means to transport the donor member past a plurality of treating stations, said treating stations including: (1) a toner loading station including a supply of toner particles at which toner particles are contacted and a layer of toner particles retained by the donor member in response to microfields setup between the screen pattern electrode and the film electrode: and (2) a developing station at which the layer of retained toner particles is presented in developing relation to an electrostatic latent image on an image-retaining member, and (0) means adapted to maintain the potential difference between the electrodes sufficient to create microfields extending into the region beyond the surface of the donor member and of a magnitude sufficient to attract to and hold toner particles
  • the apparatus includes a microfield donor member adapted to transport toner particles to the latent image comprising an endless dielectric layer separating a plurality of mutually electrically isolated conductive screen pattern electrodes from a conductive continuous film electrode.
  • a means is employed which is adapted to maintain a potential difference between each screen electrode and the film electrode sufficient to create microfields extending into the region beyond the surface of the donor member and of a magnitude sufficient to attract to and hold toner particles on the surface of the donor member carrying the screen electrodes.
  • This means is also adapted to sequentially effect a field reversal of the microfields between each screen electrode and the film electrode at a time after each screen electrode region has been loaded with toner particles. The reversal is effective to remove charges from the dielectric accrued during the time period of toner loading.
  • This means is further adapted, after charge removal, to sequentially return said microfields to their former direction.
  • the apparatus includes a microfield donor member comprising an endless dielectric layer separating a continuous, electrically conductive screen pattern electrode from a plurality of mutually electrically isolated conductive film electrodes.
  • a means is employed which is adapted -to sequentially maintain a potential difference between the screen electrode and each of the film electrodes sufficient to create microfields extending into the region beyond the surface of the donor member and of a magnitude sufficient to attract to and hold toner particles on the surface of the donor member carrying the screen electrode.
  • This means is also adapted to sequentially effect a field reversal of the microfields between each film electrode and the screen electrode at a time after each film electrode region of the donor has been loaded with toner. The reversal is effective to remove charges from the dielectric accrued during the time period of toner loading.
  • This means is further adapted, after charge removal, to sequentially return said microfields to their former direction.
  • the donor member may also have both a plurality of mutually electrically isolated screen pattern electrodes and a plurality of mutually electrically isolated film electrodes, separated by an endless dielectric layer. This will permit individual control of the potential difference between the electrodes at a plurality of regions about the periphery of the donor.
  • a toner agglomerate removal station may be located adjacent the periphery of the donor member at a point between the toner loading station and the development station, a uniform charging station may be located between the toner loading station and the development station and a residual or ghost image removal station may belocated at a point beyond the development station.
  • FIG. 1 is a sectional view of xerographic apparatus in accordance with the present invention.
  • FIG. 2 is an isometric view of one section of a preferred microfield donor in accordance with the present invention
  • FIG. 3 is an isometric view of one section of another preferred microfield donor in accordance with the present invention.
  • FIG. 4 is an isometric view of one section of still another preferred microfield donor in accordance with the present invention.
  • the present invention is a transfer development system and method in which toner particles are applied to an electrostatic latent image on a photoconductive plate to develop the image.
  • the system and method is described herein as part of a xerographic copier, it can be utilized in conjunction with any reproduction system wherein a latent image is to be developed by applying toner thereto.
  • a xerographic plate is in the form of a drum which passes through stations A-E in the direction shown by the arrow.
  • the drum has a suitable photosensitive surface,such as one including selenium overlying a layer of conductive material, on which a latent electrostatic image can be formed.
  • the various stations about the periphery of the drum which carry out the reproduction process are: charging station A, exposing station B, developing station C, transfer station D, and cleaning station E.
  • Stations A, B, D, and E represent more or less conventional means for carrying out their respective functions. Apart from their association with the novel arrangement to be described with respect to stations C they form no part of the present invention.
  • a suitable charging means 112 e.g., a corotron, places a uniform electrostatic charge on the photoconductive material.
  • a light pattern via a suitable exposing apparatus 14, e.g., a projector,is exposed onto the charged surface of drum 10.
  • the latent image thereby formed on the surface of the drum is developed or made visible by the application by a finely divided pigmented, resinous powder called toner, at developing station C, which is described in greater detail below.
  • transfer station D comprising a copy sheet 16, corona charging device 18 and fusing device 20.
  • cleaning station E comprising cleaning device 22, e.g., a rotating brush, at which residual toner is removed.
  • the apparatus includes a donor member 24 (more particularly described below) rotatably mounted adjacent a toner reservoir 26, containing a supply of toner particles 28.
  • the donor member 24 is positioned so that a portion'of its periphery comes into contact with toner particles 28.
  • the donor member is also located so as to provide a small gap between the surface of drum l0 and the outer surface of a toner layer carried by donor roll 24. As toner particles are presented to the electrostatic imaged regions of drum 10, the particles traverse this small gap thereby developing the latent image.
  • the microfield nulling effects due to charge accrual at the dielectric interface or in the dielectric, can be controlled by periodically reversing the direction of the microfields involved by switcha ing the polarity of the voltage source.
  • FIGS. 2, 3 and d show several means of accomplishing this.
  • the 'microfield donor M as illustrated in FIG. 2 shows one segment of a cylindrical donor member.
  • the donor member shown consists of an endless dielectric layer 36 separating a continuous conductive screen pattern electrode 3% from a plurality of mutually electrically isolated conductive film electrodes 40.
  • the screen pattern electrode can be constructed of wires or it may be formed of an etched metal film yielding open dielectric areas.
  • Copper is a convenient metal and the dielectric islands can be from 0.01 mm to 0.08 mm in area.
  • the screen pattern electrode 30 is held at some reference potential, for example, at ground potential, as shown at 42.
  • film electrode is meant usually a continuous solid metal layer. The thickness of this layer is not critical. It may be massive in comparison to the screen electrode.
  • the electrically isolated conductive film electrodes d0 make contact with commutator segments 30 and 32 via lead and brush arrangements dd.
  • Commutator segments 30 and 32 are connected to equal but opposite-in-sign voltage sources M and 48. With this arrangement the microfield donor, during rotation, will pass through two opposite electrical zones, defined by the imaginary line M as shown in FIG. I.
  • microfield donor 24a revolves in the direction shown by the arrow in FIG. 1, and as a point on the micro field donor approaches toner tray 26, the voltage potential between one film electrode 40 and the screen electrode 38 will be placed at some predetermined level, e.g., 300 volts. This potential difference will be maintained at this segment while it is being transported through the toner tray and just past development region C. After all of this segment of microfield donor 24a passes just beyond development region C, the voltage potential is switched via the commutator to an opposite potential of predetermined level, e.g., +300 volts.
  • predetermined level e.g. 300 volts
  • donor 24b is essentially the opposite construction of that shown in FIG. 2.
  • Continuous dielectric film 36 separates a plurality of mutually electrically isolated conductive screen pattern electrodes 50 from a conductive continuous film electrode 52.
  • Conductive film 52 is held at a convenient reference potential, for example ground potential, as shown at 54.
  • the individual electrically isolated conductive screen pattern electrodes 50 make contact with commutator sections 30 and 32 via lead and brush arrangements 44.
  • the lead portions of this arrangement pass through dielectric layer 36 and insulated regions 56 of the conductive film electrodes 52. Toner loading is accomplished in the same manner as described with respect to FIG. 2.
  • the voltage between electrode 52 and one of the screen electrodes 50 is maintained at say 300 volts. This potential is maintained during the period of time that this segment of the microfield donor is passing through the tray 26 and toner 28 and through development region C. After this segment passes just beyond development region C the potential is reversed to say +300 volts. This reversal causes a change in the direction of the microfields and it is maintained in this condition until it once again approaches the region just before entry into toner tray 26. At this point once again the field is reversed via commutator section 30'where again the potential across the electrodes is returned to -300 volts.
  • the microfield donor is constructed of a continuous dielectric layer 36 which separates a plurality of mutually electrically isolated conductive screen pattern electrodes 50 from a plurality of mutually electrically isolated conductive film electrodes 52.
  • This microfield donor operates in the same manner as that illustrated in FIGS. 2 and 3.
  • Each of the electrodes 50 are kept at a separate reference potential, for example ground potential, and the electrodes 52 obtain their potential via commutator sections 30 and 32, which respectively impart a positive potential during approximately one-half of the donor revolution and a negative potential during the other half.
  • the drawing shows imaginary line 34 defining two hemicircular zones through which the donor member passes. It is to be understood,
  • the potential on a given segment of the donor need only be maintained while that segment is passing through the toner loading station. After leaving this station, and before arriving at the development station, the polarity of the field can be reversed.
  • the conditions of reversal are dependent upon a potential-time relationship. For example, if the potential during loading is 300 volts, then the reversal can be +300 volts for the same period of time but no longer or a reverse nulling effect will come into play. This means that the commutator will have to be designed to hold this particular segment of the donor at a no-charge condition after a proper time period of reversal has been completed and there-after again bring this segment to the appropriate potential just prior to again entering the toner loading station.
  • the reversal potential can be at a lower level e.g. +l50 volts, but for a longer period of time, or at a higher potential, e.g., +400 volts, for a shorter period of time.
  • the reversal period may be split into two or more periods to vary or suspend the potential. For example, to minimize the toner holding force at the development station, a no-field condition can be caused to exist in the donor segments as they pass this region.
  • the invention is not limited to effecting field reversal by the particular means shown in FIGS. 2-4. Any means of causing a field reversal in order to remove the accrued charge is contemplated by the technique described.
  • the nulling effect of the accrued charge is effectively. eliminated and the microfield donor can be used without interruption for extremely long periods of time or indefinately.
  • the donor member has been described basically as a cylinder, it may be an endless belt adapted to deliver toner from the toner source to the development region.
  • a flat plate type of donor member may be utilized instead of an endless version.
  • An apparatus for developing an electrostatic latent image formed on the surface of an image-retaining member comprising: means for developing said Iatent image, said means including:
  • a microfield doner member adated to transport toner particles on the outer face thereof to said latent image comprising, a dielectric layer sandwiched between and separating first conductive electrode means from second conductive film electrode means with said first electrode means being on the outer face of said dielectric layer and said film electrode means being on the inner face of said dielectric layer; said first electrode means being arranged in a pattern to set up microfields with said film electrode means for attracting said toner particles to said donor member;
  • means adapted to maintain a potential difference between said electrodes sufficient to create voltage induced microfields extending into the-region beyond the surface of said donor member and of a magnitude sufficient to attract to and hold toner particles on the surface of said donor member carrying said electrode means, said last defined means being further adapted to effect a voltage induced field reversal of said microfields at a time after toner loading of the donor, said reversal being effective to remove charges from the dielectric accrued during the time period of toner loading, said last defined means being further adapted, after charge removal, to return the microfields to their former direction.
  • An apparatus for developing an electrostatic latent image formed on the surface of an image-retaining member comprising: means for developing said latent image, said means including:.
  • a microfie'ld donor member adapted to transport toner particles on the outer face thereof to said latent image
  • a microfie'ld donor member adapted to transport toner particles on the outer face thereof to said latent image
  • said latent image comprising an endless dielectric layer sandwiched between and separating a plurality of mutually electrically isolated conductive screen pattern electrodes from a conductive continuous film electrode with said screen electrodes being on the outer face of said dielectric layer for attracting said toner particles to said donor member and said film electrode being on the inner face of said dielectric layer;
  • means to transport the surface of said donor memmeans adapted to maintain a potential difference between each screen electrode and-said film electrode as each screen electrode region is brought to said loading station, said potential difference being sufficient to create voltage induced microfields extending into the region beyond the surface of said donor member and of a magnitude sufficient to attract to and hold toner particles on the surface of said donor member carrying said screen electrodes, said means being further adapted, after each screen electrode region is loaded with toner, to effect a voltage induced field reversal of said microfields,
  • said reversal being effective to' remove charges from said dielectric accrued during the time period of toner loading, said means being further adapted, after charge removal, to sequentially return the microfields to their former direction.
  • An apparatus for developing an electrostatic latent image formed on the surface of an image-retaining member comprising: means for developing said latent image, said means including:
  • a microfield donor member adapted to transport toner particles on the outer face thereof to said latent image comprising an endless dielectric layer sandwiched between and separating a continuous, electrically conductive, screen pattern electrode from a plurality of mutually electrically isolated conductive film electrodes with said screen electrode being on the outer face of said dielectric layer for attracting said toner particles to said donor member and said film electrodes being on the inner face of said dielectric layer;
  • a toner loading station including a supply of toner particles at which toner particles are contacted by and a layer of toner particles retained by said donor member in response to microfields set up between said screen pattern electrode and said film electrodes;
  • An apparatus for developing an electrostatic latent image formed on the surface of an image-retaining member comprising: means for developing said latent image, said means including:
  • a microfield donor member adapted to transport toner particles on the outer face thereof to said latent image comprising an endless dielectric layer sandwiched between and separating a plurality of mutually electrically isolated conductive screen pattern electrodes from a plurality of mutually electrically isolated conductive film electrodes with said screen electrodes being on the outer face of said dielectric layer for attracting said toner particles to said donor member and said film electrodes being on the inner face of said dielectirc layer;
  • a toner loading station including a supply of toner particles at which toner particles are contacted by and a layer of toner particles retained by said donor member in response to microfields set up between said screen pattern electrodes and said film electrodes;
  • c. means adapted to maintain a potential difference between said screen electrodes and said film electrodes as each screen electrode region is brought to 12 said loading station, said potential being sufficient to create voltage induced microfields extending into the region beyond the surface of said donor member and of a magnitude sufficient to attract to and hold toner particles on the surface of said donor member carrying said screen electrodes, said means being further adapted, after each screen electrode region is loaded with toner, to effect a voltage induced field reversal of said microfields, said reversal being effective to remove charges from said dielectric layer accrued during the time period of toner loading, said means being further adapted, after charge removal, to sequentially return the microfields to their former direction.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Dry Development In Electrophotography (AREA)
  • Printers Or Recording Devices Using Electromagnetic And Radiation Means (AREA)
  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)
US00121090A 1971-03-04 1971-03-04 Microfield donor with continuously reversing microfields Expired - Lifetime US3759222A (en)

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US12109071A 1971-03-04 1971-03-04

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US3759222A true US3759222A (en) 1973-09-18

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US (1) US3759222A (de)
JP (1) JPS543624B1 (de)
BE (1) BE780091A (de)
CA (1) CA951596A (de)
DE (1) DE2210337C3 (de)
FR (1) FR2128004A5 (de)
GB (1) GB1385966A (de)
IT (1) IT949779B (de)
NL (1) NL7202596A (de)

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3866574A (en) * 1973-02-15 1975-02-18 Xerox Corp Xerographic developing apparatus
US3881927A (en) * 1973-04-16 1975-05-06 Xerox Corp Half tone development process for touchdown system in electrostatic imaging
US3890929A (en) * 1973-02-15 1975-06-24 Xerox Corp Xerographic developing apparatus
US3893418A (en) * 1974-05-30 1975-07-08 Xerox Corp Xerographic developing apparatus
US3918966A (en) * 1972-09-28 1975-11-11 Commw Of Australia Liquid development of an electrical image in which a pulsating field is employed
US3929098A (en) * 1973-11-28 1975-12-30 Xerox Corp Toner loading for touchdown donor
US3958039A (en) * 1974-03-08 1976-05-18 Nitto Denki Kigyo Kabushiki Kaisha (Nitto Electric Industrial Co., Ltd.) Method for coating lead-attached electronic device
FR2299669A1 (fr) * 1975-02-03 1976-08-27 Xerox Corp Donneur xerographique a micro-champs et procede pour transporter des particules de toner chargees
US3996892A (en) * 1975-02-24 1976-12-14 Xerox Corporation Spatially programmable electrode-type roll for electrostatographic processors and the like
US3998185A (en) * 1975-02-03 1976-12-21 Xerox Corporation Microfield donors with toner agitation and the methods for their manufacture
US3999515A (en) * 1975-02-03 1976-12-28 Xerox Corporation Self-spacing microfield donors
US4017648A (en) * 1975-02-03 1977-04-12 Xerox Corporation Toner agitation through microfield donor
US4067295A (en) * 1975-03-07 1978-01-10 Xerox Corporation Magnetic microfield donor system
DE2800056A1 (de) * 1977-01-05 1978-07-13 Xerox Corp Reproduktionsmaschine, sowie elektrofotografische druckmaschine
US5220383A (en) * 1991-04-01 1993-06-15 Ricoh Company, Ltd. Developing device for an image forming apparatus having a large number of microfields formed on a developer carrier
US5239344A (en) * 1991-01-16 1993-08-24 Ricoh Company, Ltd. Developing roller having insulating and conductive areas
US5245391A (en) * 1991-04-01 1993-09-14 Ricoh Company, Ltd. Developing device having surface microfields for an image forming apparatus
US5286918A (en) * 1990-06-14 1994-02-15 Ricoh Company, Ltd. Developing apparatus using a developer carrier capable of forming microfields on the surface thereof
US5339142A (en) * 1992-07-30 1994-08-16 Xerox Corporation AC/DC spatially programmable donor roll for xerographic development
US5821973A (en) * 1994-11-18 1998-10-13 Heidelberger Druckmaschinen Ag Printing device and method
US5899608A (en) * 1998-03-09 1999-05-04 Xerox Corporation Ion charging development system to deliver toner with low adhesion
US6031552A (en) * 1994-11-18 2000-02-29 Heidelberger Druckmaschinen Ag Printing device with patterned recording surface

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JPS56165196U (de) * 1980-05-12 1981-12-07
US4515106A (en) * 1982-10-15 1985-05-07 Tokyo Shibaura Denki Kabushiki Kaisha Developing apparatus
JPS58101091U (ja) * 1982-12-03 1983-07-09 笹山　守 パイプエレメント
JPS604925A (ja) * 1983-06-23 1985-01-11 Canon Inc エレクトロクロミツク素子
FR2653241B1 (fr) * 1989-10-13 1994-03-11 Ricoh Cy Ltd Procede de developpement et appareil associe utilisant un support de revelateur qui peut former des micro-champs a sa surface.
US5716748A (en) * 1995-07-28 1998-02-10 Nippon Zeon Co., Ltd. Developer and finely particulate polymer

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US3152012A (en) * 1960-12-19 1964-10-06 Ibm Apparatus for the development of electrostatic images
US3203394A (en) * 1962-10-01 1965-08-31 Xerox Corp Xerographic development apparatus
US3216844A (en) * 1962-03-02 1965-11-09 Xerox Corp Method of developing electrostatic image with photoconductive donor member
US3332396A (en) * 1963-12-09 1967-07-25 Xerox Corp Xerographic developing apparatus with controlled corona means

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US3152012A (en) * 1960-12-19 1964-10-06 Ibm Apparatus for the development of electrostatic images
US3216844A (en) * 1962-03-02 1965-11-09 Xerox Corp Method of developing electrostatic image with photoconductive donor member
US3203394A (en) * 1962-10-01 1965-08-31 Xerox Corp Xerographic development apparatus
US3332396A (en) * 1963-12-09 1967-07-25 Xerox Corp Xerographic developing apparatus with controlled corona means

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3918966A (en) * 1972-09-28 1975-11-11 Commw Of Australia Liquid development of an electrical image in which a pulsating field is employed
US3866574A (en) * 1973-02-15 1975-02-18 Xerox Corp Xerographic developing apparatus
US3890929A (en) * 1973-02-15 1975-06-24 Xerox Corp Xerographic developing apparatus
US3881927A (en) * 1973-04-16 1975-05-06 Xerox Corp Half tone development process for touchdown system in electrostatic imaging
US3929098A (en) * 1973-11-28 1975-12-30 Xerox Corp Toner loading for touchdown donor
US3958039A (en) * 1974-03-08 1976-05-18 Nitto Denki Kigyo Kabushiki Kaisha (Nitto Electric Industrial Co., Ltd.) Method for coating lead-attached electronic device
US3893418A (en) * 1974-05-30 1975-07-08 Xerox Corp Xerographic developing apparatus
US3999515A (en) * 1975-02-03 1976-12-28 Xerox Corporation Self-spacing microfield donors
US4114261A (en) * 1975-02-03 1978-09-19 Xerox Corporation Method of manufacture of a xerographic microfield donor
US3998185A (en) * 1975-02-03 1976-12-21 Xerox Corporation Microfield donors with toner agitation and the methods for their manufacture
FR2299669A1 (fr) * 1975-02-03 1976-08-27 Xerox Corp Donneur xerographique a micro-champs et procede pour transporter des particules de toner chargees
US4017648A (en) * 1975-02-03 1977-04-12 Xerox Corporation Toner agitation through microfield donor
US3996892A (en) * 1975-02-24 1976-12-14 Xerox Corporation Spatially programmable electrode-type roll for electrostatographic processors and the like
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DE2800056A1 (de) * 1977-01-05 1978-07-13 Xerox Corp Reproduktionsmaschine, sowie elektrofotografische druckmaschine
US5286918A (en) * 1990-06-14 1994-02-15 Ricoh Company, Ltd. Developing apparatus using a developer carrier capable of forming microfields on the surface thereof
US5239344A (en) * 1991-01-16 1993-08-24 Ricoh Company, Ltd. Developing roller having insulating and conductive areas
US5220383A (en) * 1991-04-01 1993-06-15 Ricoh Company, Ltd. Developing device for an image forming apparatus having a large number of microfields formed on a developer carrier
US5245391A (en) * 1991-04-01 1993-09-14 Ricoh Company, Ltd. Developing device having surface microfields for an image forming apparatus
US5339142A (en) * 1992-07-30 1994-08-16 Xerox Corporation AC/DC spatially programmable donor roll for xerographic development
US5821973A (en) * 1994-11-18 1998-10-13 Heidelberger Druckmaschinen Ag Printing device and method
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Also Published As

Publication number Publication date
IT949779B (it) 1973-06-11
DE2210337C3 (de) 1978-12-21
FR2128004A5 (de) 1972-10-13
JPS543624B1 (de) 1979-02-24
CA951596A (en) 1974-07-23
BE780091A (fr) 1972-09-04
DE2210337A1 (de) 1972-09-07
NL7202596A (de) 1972-09-06
GB1385966A (en) 1975-03-05
DE2210337B2 (de) 1978-05-03

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