US3921578A - Power cascade electrophotographic development - Google Patents

Power cascade electrophotographic development Download PDF

Info

Publication number
US3921578A
US3921578A US268309A US26830972A US3921578A US 3921578 A US3921578 A US 3921578A US 268309 A US268309 A US 268309A US 26830972 A US26830972 A US 26830972A US 3921578 A US3921578 A US 3921578A
Authority
US
United States
Prior art keywords
developer
belt
development
drum
development zone
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
US268309A
Other languages
English (en)
Inventor
James E Genthe
Edward F Mayer
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.)
Ricoh Co Ltd
Original Assignee
Itek 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 Itek Corp filed Critical Itek Corp
Priority to US268309A priority Critical patent/US3921578A/en
Priority to GB2882173A priority patent/GB1424369A/en
Priority to FR7324162A priority patent/FR2237231B3/fr
Priority to SE7309316A priority patent/SE382697B/xx
Priority to IT26108/73A priority patent/IT990870B/it
Priority to NL7309238A priority patent/NL7309238A/xx
Priority to JP48074471A priority patent/JPS4953839A/ja
Priority to DE19732333877 priority patent/DE2333877A1/de
Priority to BE133049A priority patent/BE801830A/xx
Application granted granted Critical
Publication of US3921578A publication Critical patent/US3921578A/en
Assigned to RICOH COMPANY, LTD. reassignment RICOH COMPANY, LTD. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: ITEK CORPORATION
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • G03G15/0801—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer for cascading

Definitions

  • the developer has a movable, flexible belt having a roughened surface which is spaced in a parallel relationship to a portion of a photoconductive drum surface to define a development zone.
  • the belt is moved upwardly thereby creating additional turbulence in the development zone beyond that normally present in cascade development.
  • This invention relates to electrophotographic apparatus and more particularly to an improved electrophotographic development apparatus for applying solid developer materials to latent electrostatic charge images on the surface of an insulating layer.
  • a conductive backing having a photoconductive insulating layer thereon is imaged by first uniformly electrostatically charging its surface, and subsequently exposing the charged surface to a pattern of activating electromagnetic radiation, such as light.
  • the radiation pattern selectively dissipates electrostatic charges in the illuminated areas on the photoconductive surface, which results in a latent electrostatic image in the nonilluminated areas.
  • This latent electrostatic image can then be developed to form a visible image by depositing finely divided, oppositely charged electroscopic marking particles, commonly called toner, on the surface of the photoconductive insulating ,layer.
  • Developed toner images can be fused to the insulating surface, or transferred and fused to another substrate such as plain paper.
  • Solid electrophotographic developer materials are customarily two component systems containing finely divided toner particles and relatively coarser, larger carrier beads. Toner particles and carrier beads are chosen or modified to make them triboelectrically dissimilar, so that triboelectric charges are generated upon each during the development process. Additionally, the components are chosen so that the toner will have triboelectric charges thereon opposite in sign to the electrostatic charge pattern to be developed. Thus, toner particles adhere to the carrier particles because of their opposite electrostatic charges and because of van der Waals forces, until they are mechanically jarred loose and captured by the opposite and stronger electrostatic charges on the insulating surface to be developed.
  • One type of development apparatus described in the prior art uses a belt to pull magnetic developer material by a photoconductive drum with an electrostatic image thereon. See Byrne, U.S. Pat. No. 2,832,31 1, FIG. 3. This is one type of magnetic brush development.
  • Other general types for solid developer materials include fur brush development, impression development and powder-cloud development.
  • cascade development The most widely used method of developing latent electrostatic images with these two-component developer materials, however, is known as cascade" development.
  • cascade development the developer is caused to flow by gravity over the electrostatic charge bearing surface to effect image development.
  • toner laden carrier beads flow over and collide with the photoconductive surface, toner is stripped from carrier beads and deposited upon the plate surface in the pattern of the latent electrostatic image thereon.
  • development electrodes formed from metallic sheets held in a stationary position close to and parallel to the surface of xerographic plates and electrically coupled to the metal backing of the plate have been used in many cascade developers.
  • the effect of development electrodes is to change the field configuration of the electrostatic image and to increase the field in the space above large solid areas of charge.
  • development electrodes cause other problems, such as blocking. This is a gradual buildup of developer on the electrode surface. Its effect is to reduce the efficiency of the electrode, and if present to a serious degree, it can even block the passage of further developer through the development zone. In extreme cases, blocking can also cause developer materials to score the delicate photoconductor surface.
  • the probability of a developing event i.e., the capture of a toner particle by the latent electrostatic image
  • the probability of a developing event is strongly dependent on the capability to control the configurational and dynamic parameters of developer at the electrostatic image.
  • it is essential to have some control over these parameters at the latent electrostatic image.
  • the preferred embodiment of this invention may be referred to as a power cascade xerographic development apparatus. It includes a moving belt which is positioned closely to and parallel to a portion of the photoconductive insulating surface, which is often a vitreous selenium drum. A development zone is thus defined between the belt and insulating surface. Electroscopic developer containing carrier beads and toner particles is introduced at the upper or inlet end of this zone and, after" development has taken place, developer exits from an outlet end.
  • the belt is flexible in its longitudinal direction so that it will conform to the shape of the photoconductive insulating surface, but is preferably at least semirigid in its transverse direction so that it remains equally spaced from the surface across its width.
  • control of the dynamic parameters can be achieved at the.latent electrostatic image be cause developer flows between two moving surfaces, i.e., the moving belt and the photoconductive, insulating surface.
  • the turbulence increases markedly over that caused solely by gravity flow of developer.
  • Increased turbulence in the development zone causes better carrier-toner separation resulting in more activated toner being available near the photoconductor surface for development to increase development efficiency.
  • Activated toner is created by the mechanical jarring which occurs in the development zone which helps the latent image overcome the electrostatic and va der Waals forces binding toner particles to carrier beads.
  • Increased turbulence also provides more uniform development over the entire development zone including the elimination of direction effects often noticeable with prior cascade developers.
  • Increased turbulence is achieved with the development apparatus described herein by varying the belt speed and direction to modify all of the velocity vectors of developer passing through the development zone.
  • the mean carrier tangential velocity can be reduced in the zone by moving the belt in a reverse direction thereby increasing the means carrier density in the zone; similarly, the mean carrier density can be lowered by running the belt in a forward direction to increase the means carrier tangential velocity.
  • carrier density i.e., the number of carrier beads per unit volume of development zone
  • the means carrier bead tangential velocity normally dependent entirely on gravity, can be adjusted by varying the belt speed and direction. In fact, the belt motion affects all components of carrier velocity.
  • Radial and angular velocities are increased because of reflection of carriers from the belt. This is particularly noticeable when the belt is moved in the reverse direction.
  • the belt is driven in a direction opposite to the gravitational forces acting on the carrier beads, i.e, the reverse" direction.
  • the tangential velocity of carrier can be lowered, thereby overcoming its natural tendency to accelerate and fly away from the drum surface.
  • This results in better development and better scavenging because carrier and toner stay close to the photoconductor for a much longer effective time throughout the development zone.
  • carrier density can be increased, a corresponding reduction in mass flow rate is possible which results in reduced abrasion of the drum surface and toner, and also provides for quieter machine operation and longer developer life.
  • the turbulence of carrier and toner is especially increased in this mode since the reverse direction of the belt particularly imparts perpendicular and angular velocity components thereto.
  • Blocking is also eliminated or substantially reduced with the power cascade development apparatus of this invention. This is because: (1) there is much more turbulence in the development zone; and, (2) both walls of the development zone are moving.
  • the net result of the new control over cascade development parameters in the development zone provided by the power cascade developer described herein is quieter machine operation, improved reliability, higher quality development, and faster development speeds or in the alternative, equivalent development speeds with smaller more compact photoconductive drums.
  • the machine can be quieter since lower mass flow rates of developer can be used and is more reliable since problems such as blocking are eliminated.
  • High quality is provided because of the increased turbulence which results in higher optical densities in image areas, better scavenging in background areas, and also eliminates direction effects. Finally, higher development speeds.
  • drums can be used at equivalent speeds, because the increased turbulence increases the probability of a development event occuring, because the developer is held close to the photoconductor through essentially the entire development zone, and because the development zone can be actually or effectively lengthened.
  • FIG. 1 is a schematic representation of a typical xerographic photocopying apparatus employing cascade development
  • FIG. 2 is a cut-away, schematic view of one embodiment of a development apparatus of this invention.
  • FIG. 3 is a partially cut-away, schematic illustration of an alternate embodiment of a developer apparatus of this invention.
  • FIG. 4 is a partially cut-away perspective view of a section of movable belt used in the development apparatus of this invention.
  • FIG. 1 illustrates a typical prior art, xerographic copy machine employing a cascade development apparatus.
  • a xerographic drum 1 comprising a conductive metal substrate such as aluminum is covered on its outer surface with a layer of photoconductive insulating material, typically vitreous selenium.
  • Drum 1 rotates about its axis, and is shown rotating in the same direction as the gravitational forces on the carrier-toner, i.e., the downhill direction.
  • a uniform electrostatic charge is formed on the surface of drum 1 by means of corona charging unit 3.
  • Uniformly charged drum 1 then passes an imaging station 5 which exposes the charged photoconductor to a light pattern representative of the original to be reproduced thereby discharging portions of the charged photoconductive surface which are struck by light.
  • imaging station 5 Other means of forming electrostatic latent images on insulating surfaces are known in the art and may be used instead of the one shown. More specific details on suitable photoconductive elements, charging means and exposing means can be found in the following US. Pat. Nos. 3,277,957; 3,312,548; 3,552,848; 3,566,108; 3,598,991; 3,612,864; 3,615,128; 3,628,786, and others.
  • Development of the electrostatic latent image is effected by a traditional cascade development apparatus 6, which includes a number of elements surrounded by housing 7.
  • a conveyer system is formed by a belt trained to pass over two drive rollers 11 and 12.
  • Belt 10 has buckets 13 attached thereto.
  • Electroscopic developer is lifted from a reservoir 15 in buckets 13 to a point at the upper portion of drum 1 where it is dispensed onto feed guide 17.
  • Spent developer is guided back into reservoir 15 by guide 19.
  • a biased development electrode 21 is shown closely spaced to the drum surface to improve solid area coverage.
  • Toner transfer and fusing station 25 typically includes a web of paper, dispensing, windup and guide rolls for the web, a corona charging unit, and a heater. More specific details of these elements can be found in US. Pat. Nos. 3,584,195; 3,642,362; 3,647,292, and others.
  • a cleaning brush 27 removes residual toner from the surface of drum 1.
  • FIG. 1 The charging, exposure, transfer, fusing and cleaning techniques shown in FIG. 1 are believed to be representative of those commonly used. Nevertheless, many other systems may be employed in connection with the power cascade xerographic development apparatus as described herein.
  • FIG. 2 is a schematic sectional view of one embodiment of the power cascade xerographic developer of this invention.
  • a housing 30 surrounds the various elements and helps to contain any powder dust generated therein.
  • Xerographic developer material 32 is raised from the reservoir portion 34 of the development apparatus to an elevated position by bucket elevator 36 comprising a belt 38 having attached thereto buckets 40.
  • Belt 38 is trained to pass over drive roller 42, which is driven by motor 43, and guide roller 44.
  • developer material falls from buckets 40 over adjustable guide baffle 46 into feed hopper 48. Developer material is dispensed from hopper 48 by orifice 50, which can be adjusted to control the mass flow rate.
  • Developer material dispensed from hopper 48 enters a development zone formed between the surface of xerographic drum 52 and movable belt 54.
  • Belt 54 is an endless loop trained over drive roller 56, driven by motor 57, and guide rollers 58 and 60 so that the run of the belt consists of three distinct portions. In the first portion, extending between rollers 56 and 58, the belt travels in a closely spaced and parallel relationship to drum 52, but in the opposite direction. After the belt passes around rollers 58, it travels away from the drum 52 to roller 60, and then starts its third path back to roller 56. Developer exiting from the development zone formed between drum surface 52 and movable belt 54 is directed by semicircular baffle 69 back to reservoir 34.
  • Movable belt 54 is constructed of a flexible material such as a silicone rubber.
  • belt 54 has stiffeners 62 extending through the belt in a transverse direction to make the belt semirigid in the width direction, which is preferred. The stiffeners help in maintaining the belt an equal distance from drum 52 across its width. Also, the ends of stiffening rods 62 can be inserted in a drive ring mounted at the end of the drum to provide a convenient drive for the belt, if desired.
  • the orifice 50 is adjusted to a predetermined opening and developer is allowed to fill hopper 48 to the point where it overflows.
  • the overflow developer is caught in a return chute formed by elements 61 and 62.
  • Baffles 64 reduce the velocity of returning overflow developer to eliminate unnecessary powder cloud generation in the reservoir 34.
  • Disc 68 can be moved toward or away from the downhill path of belt 38 to thereby act as a tensioning device for belt 38.
  • Baffle 66 helps to furtherseal off the reservoir portion 34 of developer apparatus 36, helping to contain any loose toner particles therein.
  • a significant feature of this invention is that the belt moves during development.
  • the belt has a much greater effect on developer than the photoconductive surface. This is because the belt can have a rough surface whereas the photoconductor is smooth, and also because the developer tends to fly away from the photoconductive drums surface due to centrifugal force. In regard to the latter, the belt acts to contain developer and to redirect developer falling away from the drum back towards the drum surface. If run in the reverse direction, it also lowers the mean carrier tangential velocity.
  • Increased turbulence results from the movable member or belt causing substantial changes in the magnitude and direction of the velocity vectors of carrier beads descending through the development zone under the influence of gravity.
  • Carrier beads are forced to move randomly rather than in a pattern wherein nearly all of them have velocity vectors of substantially the same magnitude and direction.
  • the increased turbulence provides a greater number of carrier collisions per unit volume of development zone thereby shaking loose more toner particles and increasing the probability of a development event occurring.
  • the belt can be moved in a forward or reverse direction, regardless of whether the photoconductive drum is held stationary, or moved in an uphill or downhill direction.
  • forward means the same direction as the gravitational forces on the developer and reverse means the direction opposite to the gravitational forces.
  • the belt should have a linear velocity of at least one inch per second in order to have a significant effect.
  • the belt has a forward or reverse linear velocity of from about to 40 inches per second.
  • the drum will be moving, and the most preferred case is to run the belt within the preferred ranges above and also from about 0.5 to about 4 times the linear velocity of the drum surface for both the forward and reverse embodiments and for both uphill and downhill drum direction.
  • the movable member or belt is preferably spaced a distance equal to between about three and ten carrier diameters from the photoconductive surface. For most of the commonly available xerographic developers, this distance is between about 0.030 and 0.150 inches.
  • FIG. 3 is a cross-sectional schematic view of an alternate developer apparatus of this invention. As shown, this developer apparatus is used with a drum 71 rotated about a center shaft 72 in a downhill direction. A sheet of zinc oxide paper 73 having an electrostatic image thereon is shown about to enter the development zone of development apparatus 74. Paper 73 can be fastened to drum 71 any conventional means such as releasable jaws.
  • Development apparatus 74 has an outer housing 75 which can be, for example, sheet metal.
  • a belt 76 is shown and is similar to that described above in FIG. 2 and as further described in FIG. 4 below.
  • Belt 76 passes around drive roller 77, driven by motor 90, and guide rollers 78 and 79, and travels in the same direction as the surface of drum 71. Spacers 80 help to maintain belt 76 an equal distance from guide baffle 81.
  • Development apparatus 74 also contains an elevator belt 82 trained to pass in a vertical direction over guide roller 83 and roller 84, which is driven by motor 91, and to work in cooperation with belt 76 to form an elevator for developer material 85 stored in reservoir section 86.
  • Spacers 87 are attached to belt 82 to maintain it the desired distance from developer belt 76 in the vertical elevator portion of the apparatus.
  • a guide 88 is placed behind the other side of elevator belt 82 to further help in maintaining proper spacing in the elevator section thereof.
  • Developer 85 collects at the top of the elevator section and enters inlet section 89 of the development zone formed between drum 71 and belt 76.
  • belt 76 moves developer along, it is possible to extend the development zone further than would be possible with a normal cascade development system which relies solely on gravity for developer transport. As can be appreciated from FIG. 3, developer belt 76 assists gravitational forces in the downhill verticle sections of the development zone, and substitutes for them in horizontal sections or uphill verticle sections.
  • FIG. 4 is a partially cutaway prospective view of a belt suitable for use in the development apparatus of this invention.
  • the belt 100 can be a silicon rubber or other flexible material such as polyurethane or even metal.
  • the belt material will be triboelectrically compatible with the developer.
  • Belt 100 has a relatively thin surface with saw tooth backing members 103, which provides it with strength but flexibility in the longitudinal direction.
  • Cylindrical rods 102 extend through reinforcing members 103 across the width of belt 100 to stiffen it in the transverse direction.
  • the belt itself is nonconductive with conductive areas 104 regularly spaced thereon. Also, the entire belt can be conductive. In either case, the belt can serve the function of a development electrode, i.e., to enhance solid area coverage or alternately to suppress background.
  • Roughening the belt surface increases the effect of the belt. Knurled surfaces, ridge patterns, knap surfaces, etc. can be used. Roughened surfaces are particularly preferred where the belt velocity is low.
  • a power cascade electrophotographic development apparatus similar to the one illustrated in FIG. 2 was used to produce actual experimental data.
  • An 8-inch diameter aluminum drum with a zinc oxide Electrofax sheet pinned thereto was used as the photoconductor.
  • a cast silicone rubber belt with approximately 0.150 inch diameter steel reinforcing rods spaced uniformly inches apart and extending through the belt was used. This belt is similar to that illustrated in FIG. 4, except that it was totally dielectric.
  • the width of the belt was 9 inches, which provided and 8 /2 inch development area on the sheet.
  • a development zone was formed with of arc wherein the top of the zone was positioned at 60 from the horizontal so that the zone consisted of both normal and inverted cascade development. The spacing between the belt and photoconductor surface was maintained at a uniform distance of 0.080 inches.
  • I-Iunt Chemical 50-25 negative-working electroscopic developer was introduced in the developmentzone at a mass flow rate of about 30 grams per inch per second.
  • the Electrofax sheets were uniformly negatively charged to a surface potential of about 400 volts and contact printing methods were used to establish a latent electrostatic image of line copy thereon.
  • a cascade development apparatus for developing an electrostatic latent image on the surface of an insulating layer with electroscopic developer containing a mixture of carrier beads and toner particles comprising:
  • a movable member having a roughened surface positioned adjacent to at least a portion of the surface of said electrostatic latent image bearing layer to define therebetween an elongated development zone having an inlet and outlet for developer material, the development zone having a spacing be- 5 tween said roughened surface and said surface sufficient to allow developer material to pass therethrough, said spacing being between about 3 and about 10 carrier bead diameters;
  • c. means for introducing developer material at the inlet of said development zone.
  • said insulating surface has the shape of a drum and comprises a photoconductive insulating material bonded to a conductive substrate.
  • An apparatus of claim 8 additionally containing reservoir means for storing electroscopic developer.
  • An apparatus of claim 9 additionally containing means for transporting electroscopic developer from said reservoir means to the inlet of said development zone.
  • An apparatus for developing with electroscopic developer an electrostatic latent image on the surface of a rotatable drum comprising:
  • a movable belt member having a roughened surface positioned relatively close to and substantially parallel to at least a portion of said surface, the belt member and drum surface thereby defining a development zone for electroscopic developer to flow through by gravity;
  • c. means to introduce electroscopic developer at the upper end of said belt member so that it flows through said development zone.
  • An apparatus of claim 15 further including means for collecting developer material exiting from development zone and means to transport developer material from said means for collecting to said means for introducing.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Dry Development In Electrophotography (AREA)
US268309A 1972-07-03 1972-07-03 Power cascade electrophotographic development Expired - Lifetime US3921578A (en)

Priority Applications (9)

Application Number Priority Date Filing Date Title
US268309A US3921578A (en) 1972-07-03 1972-07-03 Power cascade electrophotographic development
GB2882173A GB1424369A (en) 1972-07-03 1973-06-18 Electrophotographic apparatus
SE7309316A SE382697B (sv) 1972-07-03 1973-07-02 Apparat for kaskadframkallning av en elektrostatisk, latent bild pa ytan av ett isolerande skikt medelst en elektroskopisk framkallare, som innehaller en blandning av berarkorn och tonarpartiklar
IT26108/73A IT990870B (it) 1972-07-03 1973-07-02 Apparecchio per lo sviluppo elettrofotografico con organo mobile per impartire turbolenza al materiale sviluppatore associato alla superficie portante l immagine latente elettrostatica
FR7324162A FR2237231B3 (enrdf_load_stackoverflow) 1972-07-03 1973-07-02
NL7309238A NL7309238A (enrdf_load_stackoverflow) 1972-07-03 1973-07-03
JP48074471A JPS4953839A (enrdf_load_stackoverflow) 1972-07-03 1973-07-03
DE19732333877 DE2333877A1 (de) 1972-07-03 1973-07-03 Vorrichtung zum entwickeln eines elektrostatischen latenten bildes
BE133049A BE801830A (fr) 1972-07-03 1973-07-03 Appareil a moteur de developpement electrophotographique en cascade

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US268309A US3921578A (en) 1972-07-03 1972-07-03 Power cascade electrophotographic development

Publications (1)

Publication Number Publication Date
US3921578A true US3921578A (en) 1975-11-25

Family

ID=23022384

Family Applications (1)

Application Number Title Priority Date Filing Date
US268309A Expired - Lifetime US3921578A (en) 1972-07-03 1972-07-03 Power cascade electrophotographic development

Country Status (9)

Country Link
US (1) US3921578A (enrdf_load_stackoverflow)
JP (1) JPS4953839A (enrdf_load_stackoverflow)
BE (1) BE801830A (enrdf_load_stackoverflow)
DE (1) DE2333877A1 (enrdf_load_stackoverflow)
FR (1) FR2237231B3 (enrdf_load_stackoverflow)
GB (1) GB1424369A (enrdf_load_stackoverflow)
IT (1) IT990870B (enrdf_load_stackoverflow)
NL (1) NL7309238A (enrdf_load_stackoverflow)
SE (1) SE382697B (enrdf_load_stackoverflow)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3991712A (en) * 1974-01-02 1976-11-16 Itek Corporation Cascade development station having a roughened development plate for enhancing developer mixture turbulence
US4162842A (en) * 1977-01-28 1979-07-31 Burroughs Corporation Method and apparatus for developing a latent, electrostatic image in non-impact printing
FR2507367A1 (fr) * 1981-06-09 1982-12-10 Sundstrand Data Control Courroie d'entrainement de bande magnetique et de bobines de bande
US4412733A (en) * 1981-09-02 1983-11-01 Pitney Bowes Inc. Belt developing apparatus
US20110033208A1 (en) * 2009-08-06 2011-02-10 Samsung Electronics Co., Ltd. Developing device usable with image forming apparatus and developer delivery device thereof
US20170031267A1 (en) * 2015-07-31 2017-02-02 Canon Kabushiki Kaisha Developing device, process cartridge, and image forming apparatus

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5937831B2 (ja) * 1975-01-21 1984-09-12 キヤノン株式会社 電子写真現像装置
DE3153406C3 (de) * 1980-12-05 1995-03-23 Ricoh Kk Entwicklungseinrichtung für ein elektrophotographisches Kopiergerät
US4537495A (en) * 1983-07-01 1985-08-27 Zerox Corporation Multispeed development system

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3265522A (en) * 1962-01-25 1966-08-09 Imagic Ltd Method and apparatus for developing latent images
US3284224A (en) * 1963-01-04 1966-11-08 Xerox Corp Controlled xerographic development
US3376852A (en) * 1966-12-27 1968-04-09 Xerox Corp Dielectric belt developing
US3584601A (en) * 1968-10-28 1971-06-15 Xerox Corp Magnetic brush belt development
US3662711A (en) * 1970-03-19 1972-05-16 Xerox Corp Development apparatus
US3678895A (en) * 1969-03-15 1972-07-25 Ricoh Kk Magnetic cascade development device for dry process electrophotography

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3265522A (en) * 1962-01-25 1966-08-09 Imagic Ltd Method and apparatus for developing latent images
US3284224A (en) * 1963-01-04 1966-11-08 Xerox Corp Controlled xerographic development
US3376852A (en) * 1966-12-27 1968-04-09 Xerox Corp Dielectric belt developing
US3584601A (en) * 1968-10-28 1971-06-15 Xerox Corp Magnetic brush belt development
US3678895A (en) * 1969-03-15 1972-07-25 Ricoh Kk Magnetic cascade development device for dry process electrophotography
US3662711A (en) * 1970-03-19 1972-05-16 Xerox Corp Development apparatus

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3991712A (en) * 1974-01-02 1976-11-16 Itek Corporation Cascade development station having a roughened development plate for enhancing developer mixture turbulence
US4162842A (en) * 1977-01-28 1979-07-31 Burroughs Corporation Method and apparatus for developing a latent, electrostatic image in non-impact printing
FR2507367A1 (fr) * 1981-06-09 1982-12-10 Sundstrand Data Control Courroie d'entrainement de bande magnetique et de bobines de bande
US4412733A (en) * 1981-09-02 1983-11-01 Pitney Bowes Inc. Belt developing apparatus
US20110033208A1 (en) * 2009-08-06 2011-02-10 Samsung Electronics Co., Ltd. Developing device usable with image forming apparatus and developer delivery device thereof
US8577265B2 (en) * 2009-08-06 2013-11-05 Samsung Electronics Co., Ltd. Developing device usable with image forming apparatus and developer delivery device thereof including a plurality of rotatable delivery members
US20170031267A1 (en) * 2015-07-31 2017-02-02 Canon Kabushiki Kaisha Developing device, process cartridge, and image forming apparatus
US9835975B2 (en) * 2015-07-31 2017-12-05 Canon Kabushiki Kaisha Developing device, process cartridge, and image forming apparatus

Also Published As

Publication number Publication date
IT990870B (it) 1975-07-10
DE2333877A1 (de) 1974-01-17
NL7309238A (enrdf_load_stackoverflow) 1974-01-07
JPS4953839A (enrdf_load_stackoverflow) 1974-05-25
GB1424369A (en) 1976-02-11
SE382697B (sv) 1976-02-09
BE801830A (fr) 1974-01-03
FR2237231A1 (enrdf_load_stackoverflow) 1975-02-07
FR2237231B3 (enrdf_load_stackoverflow) 1976-06-18

Similar Documents

Publication Publication Date Title
US4458627A (en) Developing apparatus for electrostatic image
US3641980A (en) Development apparatus
US3416494A (en) Xerographic development electrode
US3921578A (en) Power cascade electrophotographic development
JPS61286862A (ja) 静電写真複写機
US3662711A (en) Development apparatus
US3331355A (en) Xerographic developing apparatus
US3550556A (en) Development apparatus
US3105770A (en) Cascade development improvement
JPH0740167B2 (ja) 電子写真装置用のバイアスした掃去グリッド
US3472657A (en) Xerographic development method and apparatus
US3611992A (en) Cleanup electrode
US3638610A (en) Development apparatus
US3678895A (en) Magnetic cascade development device for dry process electrophotography
US3336905A (en) Xerographic developer apparatus
US3651784A (en) Low potential development electrode
US3620191A (en) Biased input chute
US4050413A (en) Magnetic brush crossmixing system
US3685488A (en) Xerographic development
US3375807A (en) Xerographic developer
US3550555A (en) Xerographic developer separation
US3117030A (en) Electrophotographic developing process and apparatus
US3670700A (en) Development electrode
US3666518A (en) Development means and methods for developing electrostatic images
US4105320A (en) Transfer of conductive particles