US3866574A - Xerographic developing apparatus - Google Patents

Xerographic developing apparatus Download PDF

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Publication number
US3866574A
US3866574A US432251A US43225174A US3866574A US 3866574 A US3866574 A US 3866574A US 432251 A US432251 A US 432251A US 43225174 A US43225174 A US 43225174A US 3866574 A US3866574 A US 3866574A
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United States
Prior art keywords
donor
development
image
activation
toner
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
US432251A
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English (en)
Inventor
James M Hardennrook
Paul G Andrus
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Xerox Corp
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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 US432251A priority Critical patent/US3866574A/en
Priority to CA192,003A priority patent/CA1041292A/en
Priority to GB651274A priority patent/GB1458766A/en
Priority to JP49018104A priority patent/JPS5030537A/ja
Priority to FR7405248A priority patent/FR2217738B1/fr
Priority to DE19742407380 priority patent/DE2407380C3/de
Priority to NL7402157A priority patent/NL7402157A/xx
Application granted granted Critical
Publication of US3866574A publication Critical patent/US3866574A/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
    • G03G15/065—Arrangements for controlling the potential of the developing electrode

Definitions

  • ABSTRACT An apparatus for developing a latent xerographic image is disclosed.
  • the development device comprises a toner supporting donor member adjacent, and in spaced relationship to, an image retaining member. Means are also provided to apply a pulsed electrical bias to the donor member to introduce an electrical field in the gap between the donor and image retaining member whereby the electroscopic particles are made more readily available to the charged image thereby resulting in fine image development.
  • the electric field applied across the gap is a result of a pulsed bias applied in such a manner so as to enable toner to deposit on the electrostatic image and to reduce deposition in non-image areas of the xerographic plate.
  • the instant donor development system results in excellent copy quality with reduced background development.
  • a xerographic plate comprising a layer of photoconducting and insulating material on a conducting backing is given a uniform electric charge over its entire surface and is then exposed to the subject matter to be reproduced usually by conventional projection techniques. This exposure results in discharge of the photoconductive plate whereby an electrostatic latent image is formed.
  • Development of the latent charge pattern is effected with an electrostatically charged, finely divided material such as an electroscopic powder, that is brought into surface contact with the photoconductive layer and is held thereon electrostatically in a pattern corresponding to the electrostatic latent image. Thereafter, the developed image may be fixed by any suitable means to the surface on which it has been developed or may be transferred to a secondary support to which it may be fixed or utilized by means known in the art.
  • any method employed for forming electrostatic images they are usually made visible by a development step.
  • Various developing systems are well known and include cascade, brush development, magnetic brush, powder cloud and liquid developments, to cite a few.
  • a conductive control electrode as, for example, disclosed in U.S. Pat. Nos. 2,808,023, 2,777,418, 2,573,881 and others, is highly effective in influencing electrostatic gradients to develop images having varying charge gradients and having relatively large solid image areas.
  • superior results are generally obtainable without the electrode in place.
  • 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 layer of toner particles is applied to a donor, member which is capable of retaining the particles on its surface and then the donor member is brought into close proximity to the surface of the photoconductor. In the closely spaced position, particles of toner in the toner layer on the donor member, are attracted to the photoconductor by the electrostatic charge on the photoconductor so that development takes place.
  • the toner particles must traverse an air gap to reach the imaged regions of the photoconductor.
  • the toner-laden donor actually contacts the imaged photoreceptor and no air gap is involved.
  • the toner-laden donor is rolled in non-slip relationship into and out of contact with the electrostatic latent image to develop the image in a single rapid step.
  • the toner-laden donor is skidded across the xerographic surface. Skidding the toner by as much as the width of the thinnest line will double the amount of toner available for development of a line which is perpendicular to the skid direction and the amount of skidding can be increased to achieve greater density or greater area coverage.
  • transfer development is generic to development techniques where (l 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 further object of this invention is to describe novel donor developing apparatus which enables development between a space gap formed between said donor element and image-bearing surface.
  • the above and other objects of the instant invention are attained by providing a donor member that is adjacent and in spaced relationship to a photosensitive plate and providing means for applying a pulsed bias to the donor member.
  • the applied pulse is a combination of a short intense electrical pulse to release toner from the donor and'start it towards the photoreceptor and a nominal bias to prevent background development.
  • the instant pulsed bias development system makes possible good images over larger gap widths than those possible with application of a continuous bias.
  • the instant invention results in excellent continuous tone development and line copy having little background development.
  • FIG. 1 is a cross-sectional view of a continuous automatic xerographic copying machine utilizing the developing technqiue of this invention.
  • FIG. 2 is a graphic illustration of the characteristics of the controlled pulsation technqiue utilized in the instant invention.
  • FIG. 3 is a cross-sectional view of the development system of the present invention illustrating the particular mechanism thereof.
  • FIG. 1 there is illustrated a continuous xerographic machine adapted to form an electrostatic reproduction of a copy onto a paper sheet, web or the like.
  • the apparatus includes the xerographic plate 10 in the form of a cylindrical drum which comprises the photoconductive insulating peripheral surface on a conductive substratus above.
  • the drum is mounted on an axle 15 for rotation, and driven by a motor 16 through belt 17 connected to pulley 18 secured to the shaft'or axle 15.
  • a charging element 20 Positioned adjacent the path of motion of the surface of the drum 10 is a charging element 20 comprising, for example, a positive polarity corona discharge electrode consisting of a fine wire suitably connected to a highvoltage source 22 or potentially high enough to cause a corona discharge from the electrode onto the surface of the drum 10.
  • an exposure station 23 Subsequent to the charging station 20 in the direction of rotation of the drum, is an exposure station 23 generally comprising suitable means for imposing a radiation pattern reflected or projected from an original copy 24 or to the surface of the xerographic drum.
  • the exposure station is shown to include a projection lens 25 or other exposure mechanism as is conventional in the art, preferably operating with slit projection methods to focus the moving image at the exposure slit 26.
  • a developing station adapted to transfer a developed image from the surface of the drum to a transfer web 32 that is advanced from supply roll 33 into contact with the surface of the xerographic drum at a point beneath a transfer electrode 34.
  • the web desirably continues through a fusing or fixing device 35 onto a take-up roll 36 being driven through a slip clutch arrangement 37 from motor 16.
  • electrode 34 has a corona discharge operably connected to a high-voltage source 40 whereby a powder image developed on the surface of the drum is transferred to the web surface.
  • Fusing device 35 primarily fixes the transferred powder image onto the web to yield a xerographic print.
  • the xerographic drum continues to rotate past a cleaning station 41 in which residual powder on the drums surface is removed.
  • This may include, for example, a rotating brush 42 driven by a motor 43 through a belt 44 whereby the brush bristles bear against the surface of the drum to remove residual developer therefrom.
  • further charging means, illumination means, or the like may effect electrical or controlled operations.
  • a donor member 50 Operative at the developing station 30 is a donor member 50 in the form of a cylindrical roll, as will be further described, which revolves about a center axis 51.
  • Rotation of the donor is effected by means of an axle 51 being driven by a motor 55 operating through a belt 56, preferably to drive the cylinder in the same direction as the surface rotation of the drum.
  • the speeds of the donor member and drum may be substantially the same or the donor member can travel at speeds as high as 5 to 10 times as fast as the peripheral speed of the drum to effect a greater development in imaged areas.
  • a pulse generator source 61 Also affixed to donor member 50 is a pulse generator source 61 for applying the pulsed bias potentials of the instant invention.
  • spacial gap 70 of from about 2 to mils (1 mil equals l/IOOO of an inch).
  • the actual development step within the purview of the instant invention is achieved maintaining a gap of between 2 to 7 mils between the rotatingdonor and photoreceptor utilizing a pulsed electrical field to establish the proper field relationships whereby optimum line and solid development is effected with a minimum of background deposition.
  • Any type of pulse generating source including combinations of D.C. sources, which will effec the requisite pulsing (to be discussed hereinafter) will be suitable within the purview of the present invention.
  • a powder loading station Adjacent one portion of the path of motion of the developer donor member 50 is a powder loading station which may, for example, comprise a developer hopper 57 containing a quantity of developer product 58 which may be a form of a toner or electroscopic powder.
  • the hopper opens against the donor member whereby the cylinder passes in contact with the developer supply and is contacted uniformly with the toner powder as the donor passes through the developer.
  • Other loading mechanisms may, of course, be employed including a dusting brush or the like, as is known in the art.
  • a preferred donor element of the present invention is a microfield donor consisting of a milled aluminum cylinder over which a thin layer of insulating enamel is placed, on which enamel layer there is a thinner layer of copper etched in the form of a grid pattern.
  • the enamel layer would have a thickness of about 2 X 10' inches, while the copper grid layer would be in the order of 5 X 10" inches in thickness.
  • the typical grid pattern on a donor member of this type generally has from about 120 to '6 I50 lines per inch with theratio of insulator-to-grid surface areas being about I.25 to 1.0.
  • a donor member In order that a donor member function in accordance with the instant invention, it must first be characterized by sufficient strength and durability to be employed for continuous recycling, and in addition should preferably comprise an electrical insulator or at least possess sufficient high electrical resistance of approximately l0 ohm-cm or greater. This is not to be considered an absolute limitation, since the resistivity requirement will become less than about I0 ohm-cm and below with reduced time period of exposure between the particular incremental area of the donor and the xerographic plate. Hence, the use of donor material of too low a resistivity permits excessive penetration of charge from the corona discharge source into the donor within the time of contact.
  • a microfield donor of the type described above is used as mem ber 50 of FIG. 1.
  • the four basic steps in carrying out a development process are loading the donor with toner, corona charging the toner (see corona charging element 71 of FIG. 1), passing the toner to the electrostatic latent image on the photoconductive surface, and cleaning residual toner from the donor member so as to allow repetition of the process.
  • corona charging element 71 of FIG. 1 for example, corona charging the toner, and cleaning residual toner from the donor member so as to allow repetition of the process.
  • there are additional steps such as agglomerate toner removal and corona discharging of the donor member, which steps are auxiliary to the development process.
  • a bias is applied to the grid which establishes strong electrical fringe fields between the copper grid and the grounded aluminum substrate.
  • these fields collect toner on the donor in both grid and the enamel insulator areas.
  • this layer of toner is then charged negatively using a negative corona (see 71 of FIG. 1).
  • a square pulse of certain potentials is applied by the pulse generator at the donor to effect development.
  • the overall effect of the pulsed bias is an oscillating negative and positive potential between the xerographic plate and the donor and the xerographic plate and facilitates continuous tone development.
  • the pulse cycle contemplated in the instant invention is demonstrated.
  • the single pulse cycle is considered in two components, namely, a negative part described as activation and defined by an activation potential V, which operates for a time T,, and a positive part described as development transfer, defined by a potential V which operated for a time T,,.
  • the number of times per second a pulse cycle is repeated is defined as the repetition rate R, where Where the activation and development times are given in microseconds (1 sec. 1,000,000 microseconds), and k is a proportionality constant, 1,000, the repetition rate is given in kilo-Hertz (KH A zero volt reference is used for all voltage levels. In reality, the pulse is not perfect in shape; however, rise times are small enough so that they can be neglected. In utilizing the microfield donor elements described above, the pulse is usually applied to both the grid and aluminum substrate.
  • any definition of parameters of a square pulse have to account for an activation potential V an activation time T,,, a development potential V and a repetition (or frequency) rate. These parameters may be varied to accommodate donorphotoreceptor spacings of from 2 to 20 mils (1 mil l/l000 of an inch).
  • Activation times T between 10 and 200 microseconds and development times T be tween l and 500 microseconds (repetition rates between about 1 /2 and kiloHertz) give improved results. Best results are obtained with spacings between 2 and 7 mils, activation times between 30 and 70 microseconds, and development times between 100 and 180 microseconds (repetition rates between about 4and 8 kilo-Hertz). Typical times are 50 microsecond activation time and 150 microsecond development time, resulting in a repetition rate of 5 kiloI-Iertz.
  • the activation potential at spacings of from 2 to 7 mils is about l50 volts or greater (i.e. l50 volts, 200 volts, etc.).
  • the development potential at these spaces is about +400 volts or greater (+450 volts).
  • Ranges of the activation potential (V,,) are from about l50 to 450 volts.
  • the development potential varies from about +400 to +800 volts. Any combination of V and V can be used, the preference being that the peakj amplitude of the pulses bias, i.e., the difference between V and V not exceed 800 volts.
  • the bias level during the activation portion of the pulse is such that the negative toner particles experience a field force in the direction of the photoreceptor l0 comprised of a substrate 11 and photoconductive layer 12. This force is in addition to the force produced by the potential on the photoreceptor and, for this reason, the image areas produce a higher activation force than the non-image or backgkround areas.
  • the duration of the activating field is important in that a fraction of this time is spent breaking the toner-donor bond, while the remainder is used to drive the toner toward the imaged element. Therefore, the actual position of the toner particle in the gap is dependent upon the forces applied, as well as the time duration of the activating force.
  • the bias levels which are established during the development part of the pulse are such that a negative toner particle in the gap experiences a field force away from the photoreceptor.
  • a Xerox 813 size cylindrical donor containing a grid of 120 lines per inch was loaded by rotating through a vibrating tray of toner and then charged negatively.
  • the actual transfer development step was completed by rolling the donor over a halogen doped selenium plate.
  • the donor-to-photoreceptive spacing was maintained by plastic shim stock placed on the edges of the plate. Nominal spacings of from 2 to 7 mils were used on most tests. Since the primary objective of the experimentation was to investigate development variables, the charging and loading functions were kept reasonably constant. Typical toner layers were 2 to 2 k mils thick and were checked optically. The charge on the toner layer was monitored by reading the potential above the toner layer after charging. Then the image quality measurements were made on semimicro densitometer systems and pulse variables were set and monitored on an oscilloscope at all phases of experimentation.
  • An apparatus for developing a latent electrostatic image recorded on an image retaining member comprising:
  • a donor member for supporting a uniform layer of electroscopic developing material adjacent to the image retaining member, said donor member and image retaining member being spacially disposed as to create a space gap between both members;
  • said pulse being comprised of an activation potential segment in which electroscopic particles are released from the donor member and a development potential segment of different polarity in which the electroscopic particles in non-image areas are attracted towards the donor thereby preventing particle deposition in the non-image areas.
  • spacial gap measures from about 2 to 7 mils.
  • activation potential is a negative polarity of greater than 150 volts and the development potential is a positive polarity of greater than 400 volts.
  • cylindrical donor comprises an aluminum substrate and an enamel surface layer containing an etched layer of copper in the form of a grid pattern.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Developing For Electrophotography (AREA)
  • Dry Development In Electrophotography (AREA)
US432251A 1973-02-15 1974-01-10 Xerographic developing apparatus Expired - Lifetime US3866574A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
US432251A US3866574A (en) 1973-02-15 1974-01-10 Xerographic developing apparatus
CA192,003A CA1041292A (en) 1973-02-15 1974-02-07 Xerographic developing apparatus
GB651274A GB1458766A (en) 1973-02-15 1974-02-13 Xerographic developing apparatus
JP49018104A JPS5030537A (ja) 1973-02-15 1974-02-14
FR7405248A FR2217738B1 (ja) 1973-02-15 1974-02-15
DE19742407380 DE2407380C3 (de) 1973-02-15 1974-02-15 Vorrichtung zum Entwickeln eines elektrostatischen Ladungsbildes
NL7402157A NL7402157A (ja) 1973-02-15 1974-02-15

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Application Number Priority Date Filing Date Title
US33285273A 1973-02-15 1973-02-15
US432251A US3866574A (en) 1973-02-15 1974-01-10 Xerographic developing apparatus

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US3866574A true US3866574A (en) 1975-02-18

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CA (1) CA1041292A (ja)

Cited By (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4102305A (en) * 1977-07-01 1978-07-25 Xerox Corporation Development system with electrical field generating means
JPS5442142A (en) * 1977-09-10 1979-04-03 Canon Inc Image reproducing method
DE2930619A1 (de) * 1978-07-28 1980-02-07 Canon Kk Verfahren zum entwickeln eines latenten bildes und vorrichtung hierfuer
JPS5518656A (en) * 1978-07-28 1980-02-08 Canon Inc Electrophotographic developing method
US4292387A (en) * 1978-07-28 1981-09-29 Canon Kabushiki Kaisha Magnetic developing method under A.C. electrical bias and apparatus therefor
DE3102600A1 (de) * 1980-01-28 1981-11-26 Canon K.K., Tokyo Verfahren und vorrichtung zum entwickeln magnetischer latentbilder
US4444864A (en) * 1979-07-16 1984-04-24 Canon Kabushiki Kaisha Method for effecting development by applying an electric field of bias
US4473627A (en) * 1978-07-28 1984-09-25 Canon Kabushiki Kaisha Developing method for developer transfer under electrical bias and apparatus therefor
US4528936A (en) * 1983-08-31 1985-07-16 Kabushiki Kaisha Toshiba Developing apparatus
EP0167222A1 (en) * 1984-05-31 1986-01-08 Fuji Xerox Co., Ltd. Electrostatic latent image developing method
US4566402A (en) * 1983-10-28 1986-01-28 Kabushiki Kaisha Toshiba Developing apparatus
US4579081A (en) * 1983-08-31 1986-04-01 Kabushiki Kaisha Toshiba Developing apparatus
US4586460A (en) * 1983-08-31 1986-05-06 Kabushiki Kaisha Toshiba Developing apparatus
US4596455A (en) * 1983-09-20 1986-06-24 Kabushiki Kaisha Toshiba Developing apparatus
US4632535A (en) * 1984-04-27 1986-12-30 Kabushiki Kaisha Toshiba Developing device
US4662311A (en) * 1985-03-28 1987-05-05 Fuji Xerox Company, Limited Developing device
US4674441A (en) * 1983-08-31 1987-06-23 Kabushiki Kaisha Toshiba Developing apparatus
US4836135A (en) * 1986-08-11 1989-06-06 Kabushiki Kaisha Toshiba Developing apparatus having one-component developing agent
US5025290A (en) * 1987-03-05 1991-06-18 Savin Corporation Pulsed voltage development electrode cleaner
US5030996A (en) * 1989-08-31 1991-07-09 Canon Kabushiki Kaisha Image forming apparatus with AC bias voltages for preventing developer mixture
US5032485A (en) * 1978-07-28 1991-07-16 Canon Kabushiki Kaisha Developing method for one-component developer
US5175070A (en) * 1989-09-27 1992-12-29 Canon Kabushiki Kaisha Image forming method and image forming apparatus
US5177323A (en) * 1990-10-31 1993-01-05 Kabushiki Kaisha Toshiba Developing device for developing an electrostatic latent image by a one-component developing agent
US5194359A (en) * 1978-07-28 1993-03-16 Canon Kabushiki Kaisha Developing method for one component developer
US5202731A (en) * 1989-09-27 1993-04-13 Canon Kabushiki Kaisha Image forming apparatus having an alternating bias electric field
EP0541113A1 (en) 1991-11-08 1993-05-12 Canon Kabushiki Kaisha Monocomponent-type developer for developing electrostatic image and image forming method
US5262828A (en) * 1991-12-13 1993-11-16 Minolta Camera Kabushiki Kaisha Developing bias power unit for use in an image forming apparatus
US5298949A (en) * 1991-04-16 1994-03-29 Matsushita Electric Industrial Co., Ltd. Method and apparatus for removing a portion of a developing material deposited on a non-image area of a surface of a latent image carrier
US5317370A (en) * 1991-12-13 1994-05-31 Kabushiki Kaisha Toshiba Developing apparatus including means for collecting used developing agent
US5338894A (en) * 1990-09-21 1994-08-16 Canon Kabushiki Kaisha Image forming method with improved development
US5370957A (en) * 1992-06-16 1994-12-06 Mitsubishi Kasei Corporation Electrostatic developer and electrostatic developing method
US5488465A (en) * 1991-07-26 1996-01-30 Matsushita Electric Industrial Co., Ltd. Electrophotographic developing method using magnetic developing material and apparatus employed therefor
US5634181A (en) * 1993-02-16 1997-05-27 Fuji Xerox Co., Ltd. Developing apparatus
US5985506A (en) * 1992-07-29 1999-11-16 Matsushita Electric Industrial Co., Ltd. Reversal electrophotographic developing method employing recyclable magnetic toner
US6374065B1 (en) 1999-09-06 2002-04-16 Canon Kabushiki Kaisha Speed ratio between an image holding member and a developer carrier varies according to an image ratio
US6512909B2 (en) 2000-08-03 2003-01-28 Kyocera Corporation Image forming process and apparatus and control method thereof
US20040002015A1 (en) * 2002-03-15 2004-01-01 Yoshio Ozawa Method for developing in hybrid developing apparatus
US20040022549A1 (en) * 2002-03-26 2004-02-05 Yoshio Ozawa Image forming apparatus and image forming method
US20090190970A1 (en) * 2007-07-23 2009-07-30 Ricoh Printing Systems, Ltd. Development Device and Image Forming Apparatus Using the Same

Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5518657A (en) * 1978-07-28 1980-02-08 Canon Inc Electrophotographic developing method
JPS5518658A (en) * 1978-07-28 1980-02-08 Canon Inc Electrophotographic developing method
JPS5532059A (en) * 1978-08-29 1980-03-06 Canon Inc Method and apparatus for electrophotographic developing
JPS5532060A (en) * 1978-08-29 1980-03-06 Canon Inc Method and apparatus for electrophotographic developing
JPS55118049A (en) * 1979-03-07 1980-09-10 Canon Inc Developing method
JPS55133059A (en) * 1979-04-04 1980-10-16 Canon Inc Electrophotographic developing method
JPS5640862A (en) * 1979-09-11 1981-04-17 Canon Inc Developing device
JPS56151967A (en) * 1980-04-26 1981-11-25 Canon Inc Developing device
JPS57111563A (en) * 1981-06-23 1982-07-12 Canon Inc Method and device for development
JPS5837657A (ja) * 1982-07-21 1983-03-04 Canon Inc 現像装置
JPS60118865A (ja) * 1983-11-30 1985-06-26 Canon Inc 画像形成装置
JPH0634128B2 (ja) * 1983-11-30 1994-05-02 キヤノン株式会社 画像形成装置
JPS60118866A (ja) * 1983-11-30 1985-06-26 Canon Inc 画像形成装置
GB2206261B (en) * 1987-06-22 1992-02-05 Konishiroku Photo Ind Multicolour image forming method and apparatus
US6653037B2 (en) 2000-11-20 2003-11-25 Ricoh Company, Ltd. Toner for developing latent electrostatic images, and image forming method and device
JP2006337907A (ja) * 2005-06-06 2006-12-14 Konica Minolta Business Technologies Inc 現像装置及び画像形成装置

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3012839A (en) * 1954-07-15 1961-12-12 Burroughs Corp Electrographic printer
US3332396A (en) * 1963-12-09 1967-07-25 Xerox Corp Xerographic developing apparatus with controlled corona means
US3345944A (en) * 1961-06-30 1967-10-10 Burroughs Corp Duplication of electrostatic printing
US3550153A (en) * 1967-12-27 1970-12-22 Carter S Ink Co High speed non-impact printing
US3697169A (en) * 1971-01-06 1972-10-10 Xerox Corp Electrostatic recording apparatus and method
US3707389A (en) * 1971-01-06 1972-12-26 Xerox Corp Latent electrostatic image development
US3754962A (en) * 1970-12-21 1973-08-28 Ibm Development of electrostatic images
US3759222A (en) * 1971-03-04 1973-09-18 Xerox Corp Microfield donor with continuously reversing microfields

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3346475A (en) * 1963-02-25 1967-10-10 Australia Res Lab Electrophotographic method using an unsymmetrical ac current during development
JPS5426821U (ja) * 1977-07-26 1979-02-21

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3012839A (en) * 1954-07-15 1961-12-12 Burroughs Corp Electrographic printer
US3345944A (en) * 1961-06-30 1967-10-10 Burroughs Corp Duplication of electrostatic printing
US3332396A (en) * 1963-12-09 1967-07-25 Xerox Corp Xerographic developing apparatus with controlled corona means
US3550153A (en) * 1967-12-27 1970-12-22 Carter S Ink Co High speed non-impact printing
US3754962A (en) * 1970-12-21 1973-08-28 Ibm Development of electrostatic images
US3697169A (en) * 1971-01-06 1972-10-10 Xerox Corp Electrostatic recording apparatus and method
US3707389A (en) * 1971-01-06 1972-12-26 Xerox Corp Latent electrostatic image development
US3759222A (en) * 1971-03-04 1973-09-18 Xerox Corp Microfield donor with continuously reversing microfields

Cited By (53)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4102305A (en) * 1977-07-01 1978-07-25 Xerox Corporation Development system with electrical field generating means
JPS6315579B2 (ja) * 1977-09-10 1988-04-05 Canon Kk
JPS5442142A (en) * 1977-09-10 1979-04-03 Canon Inc Image reproducing method
JPS5518656A (en) * 1978-07-28 1980-02-08 Canon Inc Electrophotographic developing method
US4292387A (en) * 1978-07-28 1981-09-29 Canon Kabushiki Kaisha Magnetic developing method under A.C. electrical bias and apparatus therefor
US4913088A (en) * 1978-07-28 1990-04-03 Canon Kabushiki Kaisha Apparatus for developer transfer under electrical bias
US5096798A (en) * 1978-07-28 1992-03-17 Canon Kabushiki Kaisha Developing method for one-component developer
JPS5832375B2 (ja) * 1978-07-28 1983-07-12 キヤノン株式会社 現像方法
US4395476A (en) * 1978-07-28 1983-07-26 Canon Kabushiki Kaisha Developing method for developer transfer under A.C. electrical bias and apparatus therefor
US4473627A (en) * 1978-07-28 1984-09-25 Canon Kabushiki Kaisha Developing method for developer transfer under electrical bias and apparatus therefor
US5032485A (en) * 1978-07-28 1991-07-16 Canon Kabushiki Kaisha Developing method for one-component developer
US5194359A (en) * 1978-07-28 1993-03-16 Canon Kabushiki Kaisha Developing method for one component developer
DE2930619A1 (de) * 1978-07-28 1980-02-07 Canon Kk Verfahren zum entwickeln eines latenten bildes und vorrichtung hierfuer
US5044310A (en) * 1978-07-28 1991-09-03 Canon Kabushiki Kaisha Developing apparatus for non-magnetic developer
US4444864A (en) * 1979-07-16 1984-04-24 Canon Kabushiki Kaisha Method for effecting development by applying an electric field of bias
DE3102600A1 (de) * 1980-01-28 1981-11-26 Canon K.K., Tokyo Verfahren und vorrichtung zum entwickeln magnetischer latentbilder
US4368687A (en) * 1980-01-28 1983-01-18 Canon Kabushiki Kaisha Method and apparatus for developing magnetic latent image
US4586460A (en) * 1983-08-31 1986-05-06 Kabushiki Kaisha Toshiba Developing apparatus
US4579081A (en) * 1983-08-31 1986-04-01 Kabushiki Kaisha Toshiba Developing apparatus
US4674441A (en) * 1983-08-31 1987-06-23 Kabushiki Kaisha Toshiba Developing apparatus
US4528936A (en) * 1983-08-31 1985-07-16 Kabushiki Kaisha Toshiba Developing apparatus
US4596455A (en) * 1983-09-20 1986-06-24 Kabushiki Kaisha Toshiba Developing apparatus
US4566402A (en) * 1983-10-28 1986-01-28 Kabushiki Kaisha Toshiba Developing apparatus
US4632535A (en) * 1984-04-27 1986-12-30 Kabushiki Kaisha Toshiba Developing device
US4707428A (en) * 1984-05-31 1987-11-17 Fuji Xerox Co., Ltd. Electrostatic latent image developing method
EP0167222A1 (en) * 1984-05-31 1986-01-08 Fuji Xerox Co., Ltd. Electrostatic latent image developing method
US4662311A (en) * 1985-03-28 1987-05-05 Fuji Xerox Company, Limited Developing device
US4836135A (en) * 1986-08-11 1989-06-06 Kabushiki Kaisha Toshiba Developing apparatus having one-component developing agent
US5025290A (en) * 1987-03-05 1991-06-18 Savin Corporation Pulsed voltage development electrode cleaner
US5030996A (en) * 1989-08-31 1991-07-09 Canon Kabushiki Kaisha Image forming apparatus with AC bias voltages for preventing developer mixture
US5175070A (en) * 1989-09-27 1992-12-29 Canon Kabushiki Kaisha Image forming method and image forming apparatus
US5202731A (en) * 1989-09-27 1993-04-13 Canon Kabushiki Kaisha Image forming apparatus having an alternating bias electric field
US5338894A (en) * 1990-09-21 1994-08-16 Canon Kabushiki Kaisha Image forming method with improved development
US5504272A (en) * 1990-09-21 1996-04-02 Canon Kabushiki Kaisha Magnetic toner having defined particle distribution
US5177323A (en) * 1990-10-31 1993-01-05 Kabushiki Kaisha Toshiba Developing device for developing an electrostatic latent image by a one-component developing agent
US5298949A (en) * 1991-04-16 1994-03-29 Matsushita Electric Industrial Co., Ltd. Method and apparatus for removing a portion of a developing material deposited on a non-image area of a surface of a latent image carrier
US5488465A (en) * 1991-07-26 1996-01-30 Matsushita Electric Industrial Co., Ltd. Electrophotographic developing method using magnetic developing material and apparatus employed therefor
US5543901A (en) * 1991-07-26 1996-08-06 Matsushita Electric Industrial Co., Ltd. Electrophotographic developing method using magnetic developing material and apparatus employed therefor
US5348829A (en) * 1991-11-08 1994-09-20 Canon Kabushiki Kaisha Monocomponent-type developer for developing electrostatic image and image forming method
EP0541113A1 (en) 1991-11-08 1993-05-12 Canon Kabushiki Kaisha Monocomponent-type developer for developing electrostatic image and image forming method
US5317370A (en) * 1991-12-13 1994-05-31 Kabushiki Kaisha Toshiba Developing apparatus including means for collecting used developing agent
US5262828A (en) * 1991-12-13 1993-11-16 Minolta Camera Kabushiki Kaisha Developing bias power unit for use in an image forming apparatus
US5370957A (en) * 1992-06-16 1994-12-06 Mitsubishi Kasei Corporation Electrostatic developer and electrostatic developing method
US5985506A (en) * 1992-07-29 1999-11-16 Matsushita Electric Industrial Co., Ltd. Reversal electrophotographic developing method employing recyclable magnetic toner
US5634181A (en) * 1993-02-16 1997-05-27 Fuji Xerox Co., Ltd. Developing apparatus
US6374065B1 (en) 1999-09-06 2002-04-16 Canon Kabushiki Kaisha Speed ratio between an image holding member and a developer carrier varies according to an image ratio
US6512909B2 (en) 2000-08-03 2003-01-28 Kyocera Corporation Image forming process and apparatus and control method thereof
US20040002015A1 (en) * 2002-03-15 2004-01-01 Yoshio Ozawa Method for developing in hybrid developing apparatus
US6868240B2 (en) 2002-03-15 2005-03-15 Kyocera Corporation Method for developing in hybrid developing apparatus
US20040022549A1 (en) * 2002-03-26 2004-02-05 Yoshio Ozawa Image forming apparatus and image forming method
US6829448B2 (en) 2002-03-26 2004-12-07 Kyocera Corporation Image forming apparatus and image forming method
US20090190970A1 (en) * 2007-07-23 2009-07-30 Ricoh Printing Systems, Ltd. Development Device and Image Forming Apparatus Using the Same
US8073369B2 (en) 2007-07-23 2011-12-06 Ricoh Company, Ltd. Development device transferring only a toner layer to a developing roller and image apparatus using the same

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JPS5030537A (ja) 1975-03-26
CA1041292A (en) 1978-10-31

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