US3915121A - Development apparatus - Google Patents

Development apparatus Download PDF

Info

Publication number
US3915121A
US3915121A US416898A US41689873A US3915121A US 3915121 A US3915121 A US 3915121A US 416898 A US416898 A US 416898A US 41689873 A US41689873 A US 41689873A US 3915121 A US3915121 A US 3915121A
Authority
US
United States
Prior art keywords
development
developer
field generating
magnetic field
magnetic
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
US416898A
Other languages
English (en)
Inventor
David G Wilcox
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xerox Corp
Original Assignee
Xerox Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Xerox Corp filed Critical Xerox Corp
Priority to US416898A priority Critical patent/US3915121A/en
Priority to DE2440308A priority patent/DE2440308C3/de
Priority to CA208,533A priority patent/CA1030753A/en
Priority to NL7413619A priority patent/NL7413619A/xx
Priority to FR7436713A priority patent/FR2251846B1/fr
Priority to GB48871/74A priority patent/GB1480087A/en
Priority to JP1974137036U priority patent/JPS554839Y2/ja
Priority to AU75283/74A priority patent/AU7528374A/en
Priority to IT29490/74A priority patent/IT1025742B/it
Priority to US05/562,290 priority patent/US3982498A/en
Application granted granted Critical
Publication of US3915121A publication Critical patent/US3915121A/en
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
    • G03G15/09—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer using magnetic brush

Definitions

  • the baffle means is po- 1 sitioned between a supply means and the development zone and extends inwardly of each of the ends of a de- [56] References Clted velopment means which preferably comprises a mag- UNITED STATES PATENTS netic brush.
  • the baffle means comprises stationary 2,892,446 6/1959 Olden 118/637 magnetic brushes formed of developer material- The 2,904,000 9/1959 Fisher et a1.
  • This invention relates to a development apparatus for developing electrostatic images upon a moving imagebearing surface.
  • Flow baffle means are included for regulating the flow of developer to the development zone.
  • the flow baffle means comprise stationary magnetic brushes.
  • flow baffle means are provided for regulating the flow of developer to the development zone.
  • the baffle means are positioned between the supply means and the development zone and extend inwardly of each of the ends of the development means and have a limited extension in the direction of movement of the development means.
  • the baffle means in accordance with this invention, comprise stationary magnetic brushes which are effective to limit the flow of developer at the end portions of the development means.
  • the development apparatus comprises a magnetic brush development apparatus and the development means includes a magnetic brush support means, means for,
  • the stationary magnetic brush flow baffles of this invention are preferably formed by means of a magnetic field generated externally of the development means.
  • the magnetic field generating means preferably comprises a permanent magnet and most preferably a magnet having a wedge shape to provide a less abrupt flow rate disturbance.
  • mechanical flow blocks separate from the stationary brush flow baffles can be employed which are positioned between the flow baffles and the supply means.
  • FIG. 1 shows a top view in partial cross-section of a prior art magnetic brush development means.
  • FIG. 2 shows a schematic view in partial cross-' section of an electrostatographic reproducing machine in accordance with this invention.
  • FIG. 3 is a partial front view in partial cross-section along the line 3-3 in FIG. 2.
  • FIG. 4 is a top view in partial cross-section of a magnetic brush development means in accordance with this invention.
  • FIG. 5 is a partial cross-section of a magnetic brush apparatus having one embodiment of a flow baffle in accordance with this invention.
  • FIG. 6 is a partial cross-section of a magnetic brush apparatus having a flow baffle in accordance with a different embodiment of the present invention.
  • FIG. 7a and 7b comprise a graph and partial cross section respectively illustrating the flow regulating effect of a stationary brush forming magnet in accordance with one embodiment of the invention.
  • FIGS. 8a and 8b comprise a graph and partial crosssection respectively illustrating the flow regulating effect of a stationary brush forming magnet in accordance with apreferred embodiment of this invention.
  • FIG. 1 there is shown a magnetic brush 1 formed in accordance with a prior art magnetic brush roll design 2.
  • the magnetic brush roll 2 comprises a cylindrical shell 3 which has a stationary magnet 4 supported within it, which is adapted to orient and form a developer mix into a magnetic brush 1 for application to an electrostatic image on a moving image-bearing surface.
  • a generally normal field is provided along the length of the magnet 4 except at the ends 5 and 6 where fringe fields 7 and 8 are formed which have an additive effect with the normal field to provide stronger magnetic fields at the ends of the magnet.
  • baffle flow means are provided which comprise stationary magnetic brushes 21 which are effective to regulate the flow of developer at the end portions 9 and 10 of the roll 2.
  • FIG. 2 there is shown by way of example an automatic xerographic reproducing machine 30 which incorporates the magnetic brush flow baffles 20 and magnetic brush apparatus 31 of the present invention.
  • the reproducing machine 30 depicted in FIG. 1 illustrates the various components utilized therein for producing copies from an original.
  • the magnetic brush flow baffles 20 and magnetic brush apparatus 31 of the present invention are particularly well adapted for use in an automatic xerographic reproducing machine 30, it should become evident from the following description that they are equally well suited for use in a wide variety of processing systems including other electrostatographic systems and they are not necessarily limited in their application to the particular embodiment or embodiments shown herein.
  • the reproducing machine 30 illustrated in FIG. 2 employs an image recording drum-like member 32, the outer periphery of which is coated with a suitable photoconductive material 33.
  • a suitable photoconductive material is disclosed in US. Pat. No. 2,970,906, issued to Bixby in 1961.
  • the drum 32 is suitably journaled for rotation within a machine frame (not shown) by means of shaft 34 and rotates in the direction indicated by arrow 35 to bring the imagebearing surface 33 thereon past a plurality of xerographic processing stations.
  • Suitable drive means M are provided to power and coordinate the motion of the various cooperating machine components whereby a faithful reproduction of the original input scene information is recorded upon a sheet of final support material 36 such as paper or the like.
  • the various processing stations for producing a copy of an original are herein represented in FIG. 2 as blocks A to E.
  • the drum 32 moves the photoconductive surface 33 through a charging station A.
  • an electrostatic charge is placed uniformly over the photoconductive surface 33 preparatory to imaging.
  • the charging may be provided by a corona generating device of the type described in U.S. Pat. No. 2,836,725, issued to Vyverberg in 1958.
  • the drum 32 is rotated to exposure station B wherein the charged photoconductive surface 33 is exposed to a light image of the original input scene information whereby the charge is selectively dissipated in the light exposed regions to record the original input scene in the form of a latent electrostatic image.
  • a suitable exposure system may be of a type described in U.S. Pat. No. 3,062,l 10, issued to Shepard son et al. in 1962.
  • After exposure drum 32 rotates the electrostatic latent image recorded on the photoconductive surface 33 to development station C in accordance with the invention wherein a conventional developer mix is applied to the photoconductive surface 33 of the drum 32 rendering the latent image visible.
  • a suitable development station is disclosed in U.S. Pat. No. 3,707,947, issued to Reichart in 1973.
  • That patent describes a magnetic brush development system utilizing a magnetizable developer mix having ferromagnetic carrier granules and a toner colorant.
  • the developer mix is brought through a directional flux field to form a brush thereof, the electrostatic latent image recorded on the photoconductive surface 33 is developed by bringing the brush of developer mix into contact therewith.
  • development apparatus which comprises development station C will be described later by specific reference to the present invention.
  • the developed image on the photoconductive surface 33 is then brought into contact with the sheet 36 of final support material within a transfer station D and the toner image is transferred from the photoconductive surface 33 to the contacting side of the final support sheet 36.
  • the final support material may be paper, plastic, etc., as desired.
  • the sheet with the image thereon is advanced to a suitable fuser 37 which coalesces the transferred powder image thereto.
  • a suitable fuser is described in U.S. Pat. No. 2,701,765, issued to Codichini et al. in 1955.
  • the sheet 36 is advanced to a suitable output device.
  • the toner powder Although a preponderance of the toner powder is transferred to the final support material 36, invariably some residual toner remains on the photoconductive surface 33 after the transfer of the toner powder image to the final support material.
  • the residual toner particles remaining on the photoconductive surface 33 after the transfer operation are removed from the drum 32 as it moves through a cleaning station E.
  • the toner particles may be mechanically cleaned from the photoconductive surface 33 by any conventional means as, for example, the use of a blade as set forth in US. Pat. No. 3,740,789, issued to Ticknor in 1973.
  • the development apparatus 31 includes a storage portion or sump in a housing 41 for storing the developer material.
  • the top of the housing may include an opening 0 that could have a removable cover or cap (not shown).
  • the system could include a toner dispenser (not shown) disposed over the opening which periodically dispenses toner into the housing in a manner similar to that taught in US. Pat. No. 3,608,792.
  • the circulating system could be of the type where toner and/or toner plus carrier is added periodically by an operator or an attendant to the machine.
  • the development apparatus 31 includes magnetic brush rolls 42 and 43.
  • the magnetic brush applicator roll 42 includes a rotatably mounted support member in the form of a cylindrical shell or sleeve 44 and a stationary permanent magnet 45 suspended within the sleeve. The magnetic field of the magnet is oriented to form a brush-like structure of the developer mix.
  • the applicator roll 42 is immersed in the sump 40 of deve1- oper material which comprises ferromagnetic carrier particles and a toner colorant.
  • the developer mix is picked up by the outer support surface of the roll 42 by means of a pick-up magnetic field generated by stationary magnet 46 suspended within the sleeve 44, and is formed into a brush-like structure for application to the photoconductive surface 33 for development of the latent electrostatic image presented thereon. While only one applicator roll 42 is shown, any number of applicator rolls could be employed as desired.
  • the lifting roll 43 attracts the developer mix from the magnetic brush applicator roll 42 and carries it upward to be deposited on a slide 48 from which it flows into a cross-mixer 49 for return to the sump 40.
  • the lifting roll 43 is also a magnetic brush roll and comprises a cylindrical sleeve 50 'rotatably supported in the housing 41 and a fixed permanent magnet 51 supported in a stationary position within the sleeve. It is also possible in accordance with this invention to employ any desired number of lifting rolls 43. Further details of the apparatus 31 of FIG. 1 can be gained from a consideration of the aforenoted U.S. Pat. No. 3,707,947.
  • magnetic brush flow baffles 20 are provided to regulate the flow of developer at the end portions of the magnetic brush applicator roll 42.
  • the stationary magnetic brushes 21 extend inwardly from the housing 41 and inwardly of the development means which in the embodiment shown comprises the axial direction of the magnetic brush roll 42.
  • the stationary magnetic brush baffles 20 are positioned between the supply means 52 and the development zone 53. They have a limited extension or width in the direction of movement of the mag brush roll 42. This is significant since it is apparent from the drawings that the baffles 20 do not act to seal the end portions 54 and 55 of the mag brush roll 42 from the developer mix. While they can reduce or eliminate the flow of developer mix on the end portions 54 and 55 of the roll 42 between the baffles 20 and the development zone 53, they are not so operative between the baffles 20 and the supply means 52.
  • stationary magnetic brushes 21 In order to form the stationary magnetic brushes 21 in accordance with this invention, it is preferred to employ permanent magnets 22 and 23 extending out from the sides of the housing 41 and positioned externally of the housing.
  • the magnets may be held in place by any desired means such as, for example, the use of spring clips 56 as shown.
  • the field of each magnet 22 and 23 is oriented as shown to form stationary magnetic brushes 21 extending outwardly from the bottom of the housing 41 toward the applicator roll surface.
  • the stationary magnetic brushes 21 extend out from the housing 41 toward the roll 42 over less than the entire gap 57 between the housing and the roll.
  • This type of a structure permits some developer flow at the end portions 54 and 55 of the roll 42.
  • the amount of developer flow which is permitted should preferably be less than, or equal to, the rate of developer flow at the middle portion, in an axial sense, of the roll. This can result as shown in FIG. 4, in a substantially uniform magnetic brush 47 being formed over the entire operative length of the roll 42 or in one (not shown) with end portions of the brush having a reduced height as compared to the axial middle portion of the brush. Comparing FIG. 4 to FIG. 1, the effect of the magnetic brush flow baffles 20 of this invention is clearly illustrated, namely, the bulbous portions 11 and 12 of the brush 1 have been reduced to a height equal to or less than that of the brush at the axial middle of the roll 42.
  • the magnetic brush 47 on the surface of the roll is not formed over the entire axial length of the roll 42, but rather the length of the brush is dictated by the length of the magnets 45 and 46 within the roll. Since the magnetic brush flow baffles 20 of this invention are directed at eliminating the effect of the fringe fields at the ends of the magnet 45, it is preferred that they extend inwardly past the ends 58 and 59 of the magnet 45 a desired amount to offset the effect of the fringe fields.
  • a magnetic brush roll 42 approximately 15 inches long was employed having magnets 45 and 46 suspended therein of approximately 14 /2 inches long.
  • the magnets 22 and 23, in accordance with this invention to provide the stationary magnetic brush baffles 20, were selected to be approximately 1% inches long. This specific example, however, is not meant to be limitative of the invention.
  • the bafile forming magnet 22 has a magnetic field 61 associated therewith which is capable of forming a stationary magnetic brush 21.
  • the stationary magnetic brush 21 does not extend, however, over the entire gap 57 between the roll surface 44 and the bottom of the housing 41 in order to allow developer material flow in the gap 60 between the brush 21 and the roll surface 44.
  • the field 61 cooperates with the field 62 of the magnet 46 so that a magnetic brush will be formed over the entire gap 57 between the housing 41 and the roll surface 44 which is made up of two components.
  • the first component will comprise the stationary brush 21 of this invention.
  • the second component lies between the end of the stationary brush 21 and the roll surface 44 and comprises the moving magnetic brush 47 formed by the field associated with the pick-up magnet 46.
  • the field intensity of the stationary brush forming magnet 22 0.1 inches above the magnet was selected to be from about 260 to about 300 gauss. This should approximate the field intensity at the interior surface of the housing 41 adjacent the magnet 22.
  • the field intensity of the pick-up magnet 46 measured about 0.060 inches below the applicator roll surface was approximately 150 gauss.
  • the gap 57 was about 0.1 inches. In an apparatus employing these magnets a stationary magnetic brush was formed which did not extend over the entire gap 57 between the roll 42 and the interior of the housing 41.
  • FIG. 6 an alternative embodiment in accordance with the present invention is shown.
  • the field strength of the stationary brush forming magnet 22 has been substantially in creased to overcome the field of the pick-up magnet 46 so as to form a stationary brush over the entire gap 57 between the interior of the housing 41 and the roll surface 44.
  • This type of baffle is not preferred in accordance with this invention, but is included in the broad scope of the invention.
  • FIG. 3 it is apparent that if a stationary baffle brush 21' is formed over the entire gap 57 between the interior of the housing 41 and the roll surface 44, the degree to which the stationary brushes project axially inwardly of the roll surface would have to be reduced.
  • the magnets 22 and 23 would have to be reduced in length as shown in phantom by lines 25 and 26.
  • the distance between the stationary brushes 21' in the axial direction of the roll would have to be sufficiently large to permit a development brush 47 to be formed having an operative length sufficient to cover the entire copy sheet 36.
  • FIGS. 70 and 7b there is shown the effect of a stationary brush forming magnet 22 having a substantially uniform cross-section over its entire length.
  • the stationary brush 21 formed by this magnet has a substantially uniform height over substantially the entire length of the magnet and the height then falls off very rapidly at the end of the magnet. This should result approximately, as shown in FIG. 7a, in a fairly abrupt change in developer flow rate along the length of the roll 42 and, therefore, in a corresponding abrupt change in the density of the developer in the brush 47 during development of the image and a noticeable corresponding abrupt change in the density of the image transferred to the copy sheet 36.
  • FIGS. 8a and 8b there is shown a stationary brush forming magnet 22 which has a wedge shaped form wherein the thickness of the magnet decreases as the magnet projects inwardly of the applicator roll 42.
  • the stationary brush 21 formed by this type of magnet 22 is illustrated in FIG. 8b. As shown therein, there is a gradual reduction in the height of the stationary brush 21 the further it extends inwardly of the development roll 42.
  • the flow rate of the developer is shown extending in from the housing 41.
  • the flow rate shown changes gradually in substantial correspondence to the height of the stationary brush.
  • This gradual change in flow rate allows the density of the developer in the development brush 47 to also change gradually so that the density change in the image on the copy sheet also changes more gradually, therefore, creating an acceptable appearance. Therefore, it is quite apparent from a consideration of FIGS. 7 and 8 that the use of a wedge shaped stationary brush forming magnet 22 and 23 is highly desirable and preferred in accordance with this invention.
  • the stationary brush forming magnets 22 and 23 externally of the housing 41. Positioning the magnets externally of the housing allows greater flexibility since one or both magnets could be changed in the event that developer flow at the ends of the roll 42 is not acceptable. If desired, however, the magnets can be positioned internally of the housing 41 or the magnetic brush rolls 42 and 43. This approach could well be used, for example, with stationary brushes 21 which extend over the entire gap 57 between the roll surface 44 and the housing 41.
  • stationary brushes flow baffles 21 have been described with reference to their use in conjunction with the applicator roll 42, they could be employed with other magnetic brush rolls, if desired.
  • the members have a cross-section as shown and extend inwardly of the roll 42 an amount similar to the brushes 21 of the embodiment of FIG. 6. They are located between the supply means 52 and the baffles 20. The members 70 further improve the regulation of developer flow rate at the ends of the roll 42.
  • a development apparatus for developing electrostatic images upon an image bearing surface by the application of developer thereto comprising: a moving member for supporting a first magnetic brush of said developer; first magnetic field generating means for forming said first magnetic brush so that it extends out from said moving member with a first height; the improvement wherein, said apparatus further includes:
  • said height reducing means comprising a stationary member for supporting a second magnetic brush of said developer, said stationary member being spaced from'said moving member and second magnetic field generating means for forming said second magnetic brush so that it extends out from said stationary member toward said moving member so as to engage said first magnetic brush to reduce said first height.
  • said second magnetic field generating means are positioned between said supply means and said development zone and extend inwardly of each of the ends of said development means a given amount and have a limited extension in the direction of movement of said development means, whereby said second magnetic brushes as formed tend to limit the flow of developer at theend portions of said development means.
  • An apparatus as in claim 8 further including fiow blocking members extending inwardly of each of the ends of said development means said members being positioned between said supply means and said second magnetic field generating means.
  • a development apparatus for developing electrostatic images upon an image bearing surface by the application of developer thereto comprising:
  • a moving member for supporting a first magnetic brush of said developer, said member having first and second opposing ends and first and second end portions extending inwardly from said ends;
  • a stationary member for supporting a second magnetic brush of said developer, said stationary member being spaced from said moving member so as to define a gap extending from said moving member to said stationary member;
  • first magnetic field generating means for forming said first magnetic brush so that it extends out from said moving member toward said stationary member in said gap
  • second magnetic field generating means for forming said second magnetic brush so that it extends out from said stationary member toward said moving member over the entire of said gap
  • said second magnetic field generating means extending inwardly of the ends of said moving member a given amount and having a limited extension in the direction of movement of said member;

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Magnetic Brush Developing In Electrophotography (AREA)
  • Dry Development In Electrophotography (AREA)
US416898A 1973-11-19 1973-11-19 Development apparatus Expired - Lifetime US3915121A (en)

Priority Applications (10)

Application Number Priority Date Filing Date Title
US416898A US3915121A (en) 1973-11-19 1973-11-19 Development apparatus
DE2440308A DE2440308C3 (de) 1973-11-19 1974-08-22 Vorrichtung zum Entwickeln elektrostatischer Ladungsbilder
CA208,533A CA1030753A (en) 1973-11-19 1974-09-05 Development apparatus
NL7413619A NL7413619A (enrdf_load_stackoverflow) 1973-11-19 1974-10-16
FR7436713A FR2251846B1 (enrdf_load_stackoverflow) 1973-11-19 1974-11-05
GB48871/74A GB1480087A (en) 1973-11-19 1974-11-12 Development apparatus
JP1974137036U JPS554839Y2 (enrdf_load_stackoverflow) 1973-11-19 1974-11-12
AU75283/74A AU7528374A (en) 1973-11-19 1974-11-12 Development apparatus
IT29490/74A IT1025742B (it) 1973-11-19 1974-11-15 Apparecchiatura per sviluppare im gagini elettrostatografiche e macchina che la comprende
US05/562,290 US3982498A (en) 1973-11-19 1975-03-26 Development apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US416898A US3915121A (en) 1973-11-19 1973-11-19 Development apparatus

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US05/562,290 Division US3982498A (en) 1973-11-19 1975-03-26 Development apparatus

Publications (1)

Publication Number Publication Date
US3915121A true US3915121A (en) 1975-10-28

Family

ID=23651764

Family Applications (1)

Application Number Title Priority Date Filing Date
US416898A Expired - Lifetime US3915121A (en) 1973-11-19 1973-11-19 Development apparatus

Country Status (9)

Country Link
US (1) US3915121A (enrdf_load_stackoverflow)
JP (1) JPS554839Y2 (enrdf_load_stackoverflow)
AU (1) AU7528374A (enrdf_load_stackoverflow)
CA (1) CA1030753A (enrdf_load_stackoverflow)
DE (1) DE2440308C3 (enrdf_load_stackoverflow)
FR (1) FR2251846B1 (enrdf_load_stackoverflow)
GB (1) GB1480087A (enrdf_load_stackoverflow)
IT (1) IT1025742B (enrdf_load_stackoverflow)
NL (1) NL7413619A (enrdf_load_stackoverflow)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4095883A (en) * 1976-02-02 1978-06-20 Xerox Corporation Magnetic mixing apparatus and process
US4213617A (en) * 1978-04-17 1980-07-22 Lumoprint Zindler Kg (Gmbh & Co.) Assembly for sealing lead-in areas in a developer station
US4244322A (en) * 1977-03-11 1981-01-13 Tokyo Shibaura Electric Co., Ltd. Magnetic brush type developing apparatus
EP0027046A1 (en) * 1979-10-03 1981-04-15 Xerox Corporation Magnetic brush apparatus
US4596455A (en) * 1983-09-20 1986-06-24 Kabushiki Kaisha Toshiba Developing apparatus
EP0314436A3 (en) * 1987-10-28 1990-02-07 Canon Kabushiki Kaisha A developing apparatus
EP0390472A3 (en) * 1989-03-31 1991-11-06 Canon Kabushiki Kaisha A developing apparatus
US5287148A (en) * 1990-07-10 1994-02-15 Canon Kabushiki Kaisha Magnetic seal for a developing apparatus
CN100356275C (zh) * 2002-03-13 2007-12-19 精工爱普生株式会社 显影单元、显影装置、成像设备和计算机系统

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL7509870A (nl) * 1975-08-20 1977-02-22 Oce Van Der Grinten Nv Magneetrol.
JPS5552441Y2 (enrdf_load_stackoverflow) * 1976-03-29 1980-12-05
GB2141049B (en) * 1983-06-08 1986-07-23 Xerox Corp Electrostatographic development apparatus

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2892446A (en) * 1956-10-30 1959-06-30 Rca Corp Apparatus for developing electrostatic image
US2904000A (en) * 1957-05-15 1959-09-15 Century Geophysical Corp Magnetic-brush developer
US3058444A (en) * 1959-03-13 1962-10-16 American Photocopy Equip Co Apparatus for developing electrostatic image on electrographic sheet
US3133834A (en) * 1961-06-22 1964-05-19 Rca Corp Electrostatic developing apparatus
US3648656A (en) * 1969-07-08 1972-03-14 Minolta Camera Kk Dry developer for an electrostatic image developing apparatus
US3753420A (en) * 1971-08-11 1973-08-21 Olivetti & Co Spa Magnetic brush developer system
US3754526A (en) * 1971-12-17 1973-08-28 Ibm Electrophotographic development apparatus
US3822139A (en) * 1972-10-13 1974-07-02 Addressograph Multigraph Electrostatic developer device

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE792317A (fr) * 1971-12-06 1973-03-30 Warner Lambert Co Cartouches de rasoirs de securite et dispositif pour leur distribution

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2892446A (en) * 1956-10-30 1959-06-30 Rca Corp Apparatus for developing electrostatic image
US2904000A (en) * 1957-05-15 1959-09-15 Century Geophysical Corp Magnetic-brush developer
US3058444A (en) * 1959-03-13 1962-10-16 American Photocopy Equip Co Apparatus for developing electrostatic image on electrographic sheet
US3133834A (en) * 1961-06-22 1964-05-19 Rca Corp Electrostatic developing apparatus
US3648656A (en) * 1969-07-08 1972-03-14 Minolta Camera Kk Dry developer for an electrostatic image developing apparatus
US3753420A (en) * 1971-08-11 1973-08-21 Olivetti & Co Spa Magnetic brush developer system
US3754526A (en) * 1971-12-17 1973-08-28 Ibm Electrophotographic development apparatus
US3822139A (en) * 1972-10-13 1974-07-02 Addressograph Multigraph Electrostatic developer device

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4095883A (en) * 1976-02-02 1978-06-20 Xerox Corporation Magnetic mixing apparatus and process
US4244322A (en) * 1977-03-11 1981-01-13 Tokyo Shibaura Electric Co., Ltd. Magnetic brush type developing apparatus
US4213617A (en) * 1978-04-17 1980-07-22 Lumoprint Zindler Kg (Gmbh & Co.) Assembly for sealing lead-in areas in a developer station
EP0027046A1 (en) * 1979-10-03 1981-04-15 Xerox Corporation Magnetic brush apparatus
US4292924A (en) * 1979-10-03 1981-10-06 Xerox Corporation Magnetic brush apparatus
US4596455A (en) * 1983-09-20 1986-06-24 Kabushiki Kaisha Toshiba Developing apparatus
EP0314436A3 (en) * 1987-10-28 1990-02-07 Canon Kabushiki Kaisha A developing apparatus
US5084733A (en) * 1987-10-28 1992-01-28 Canon Kabushiki Kaisha Developing apparatus having developer layer regulation means
EP0390472A3 (en) * 1989-03-31 1991-11-06 Canon Kabushiki Kaisha A developing apparatus
US5177536A (en) * 1989-03-31 1993-01-05 Canon Kabushiki Kaisha Developing apparatus having a magnetic seal
US5287148A (en) * 1990-07-10 1994-02-15 Canon Kabushiki Kaisha Magnetic seal for a developing apparatus
CN100356275C (zh) * 2002-03-13 2007-12-19 精工爱普生株式会社 显影单元、显影装置、成像设备和计算机系统

Also Published As

Publication number Publication date
DE2440308C3 (de) 1981-02-05
IT1025742B (it) 1978-08-30
DE2440308A1 (de) 1975-05-22
FR2251846B1 (enrdf_load_stackoverflow) 1976-10-22
FR2251846A1 (enrdf_load_stackoverflow) 1975-06-13
NL7413619A (enrdf_load_stackoverflow) 1974-12-30
CA1030753A (en) 1978-05-09
JPS554839Y2 (enrdf_load_stackoverflow) 1980-02-05
AU7528374A (en) 1976-05-13
GB1480087A (en) 1977-07-20
DE2440308B2 (de) 1980-05-08
JPS5076836U (enrdf_load_stackoverflow) 1975-07-04

Similar Documents

Publication Publication Date Title
US3572288A (en) Development apparatus
US3982498A (en) Development apparatus
US2832311A (en) Apparatus for development of electrostatic images
US3645770A (en) Improved method for developing xerographic images
US3941469A (en) Dry type developing device for a copying apparatus or like apparatus
US4006987A (en) Apparatus for cleaning a residual toner on an electrostatic recording medium
US3915121A (en) Development apparatus
US3641980A (en) Development apparatus
IL31757A (en) Electrostatic copying method and apparatus
CA1079519A (en) Self-compensating photoconductor web
CA1171269A (en) Development system
US4039257A (en) Pretransfer corotron switching
US3570453A (en) Development apparatus
US4193376A (en) Developer powder supply in magnet brush development
US3678895A (en) Magnetic cascade development device for dry process electrophotography
US3592166A (en) Apparatus for developing electrostatic images
US3893408A (en) Toner dispensing system
CA1063596A (en) Mixing by magnetically separating particle trajectories and recombining
US4155328A (en) Magnetic brush developing unit for electrophotographic copy-machine
US3685488A (en) Xerographic development
US4292924A (en) Magnetic brush apparatus
US3709713A (en) Method for magnetic development
US4239017A (en) Development system
US4105320A (en) Transfer of conductive particles
JPS601621B2 (ja) 現像剤の補給装置