US3905332A - Electrophotographic developing apparatus using developing roller - Google Patents

Electrophotographic developing apparatus using developing roller Download PDF

Info

Publication number
US3905332A
US3905332A US410988A US41098873A US3905332A US 3905332 A US3905332 A US 3905332A US 410988 A US410988 A US 410988A US 41098873 A US41098873 A US 41098873A US 3905332 A US3905332 A US 3905332A
Authority
US
United States
Prior art keywords
developing
roller
developing solution
sheet
developed
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
US410988A
Other languages
English (en)
Inventor
Hideo Sawada
Van Hirafuji
Kenya Komada
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
Ricoh Co Ltd
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 Ricoh Co Ltd filed Critical Ricoh Co Ltd
Application granted granted Critical
Publication of US3905332A publication Critical patent/US3905332A/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
    • G03G15/10—Apparatus for electrographic processes using a charge pattern for developing using a liquid developer
    • G03G15/101—Apparatus for electrographic processes using a charge pattern for developing using a liquid developer for wetting the recording material

Definitions

  • ABSTRACT An electrophotographic developing apparatus which supplies a developing solution to only one surface of the copy sheet which is to be developed, by using a developing roller, around the periphery of which are provided multiple threads having an optimum lead angle for the supply of the solution.
  • the invention relates to electrophotographic developing apparatus, and more particularly, & :2 wet devel oping apparatus using a roller in which developing solution is supplied to only one surface of the sheet to be developed through the action of the roller.
  • Both wet and dry developing means are known in electrophotography, that is, electrostatic photography and electrostatic recording.
  • the developing solution supplied to the surface of a sheet to be developed must be well stirred, since the developing solution serves as a carrier for a toner powder mixed therein, and unless the developing solution is well stirred, there cannot be achieved a uniform supply of toner powder to the surface to be developed, which results in a disadvantageous non-uniformity of developing.
  • the present applicant has previously proposed an apparatus for developing only one surface in which a developing solution is pumped by means of a roller around the periphery of which is formed a layer of developing solution, the surface to be developed of the sheet fed into the apparatus being caused to bear against such layer.
  • the developing roller used in the developing solution of the kind described comprises either l a roller without a groove, (2) a roller with a simple groove or single thread groove, or (3) a roller having a plurality of grooves running parallel or substantially parallel to the axis of rotation.
  • a developing apparatus incorporating such a developing roller failed to provide a smooth supply of the developing solution which is essential to the effectiveness of the roller developing technique.
  • the roller without groove under I could not practically assure a smooth supply, while the roller under (2) resulted in a non-uniformity of developing in the direction of travel of the surface to be developed.
  • the roller mentioned under (3) while improved over the first mentioned roller, cannot still achieve a completely smooth supply of the developing solution and is liable to induce developing nonuniformity on the surface to be developed in the direction of the axis of rotation.
  • the present invention provides an electrophotographic developing apparatus using a roller in which the above-mentioned disadvantages are eliminated by forming on the periphery of the developing roller multiple threads having a suitable lead angle.
  • a developing appa ratus using a roller which eliminates the various disadvantages of the prior apparatus of this kind and capable of a smooth supply of developing solution to remove developing non-uniformity by forming on the developing roller multiple threads having a lead angle equal to or greater than Lm/v. 1)
  • developing solution once used can be scraped off from the periphery of the developing roller by means of a cleaning member, thereby enabling fresh developing solution to be continuously supplied to the surface to be developed.
  • FIG. I is a schematic cross section of a developing apparatus using a roller in accordance with one embodiment of the present invention.
  • FIG. 2 is a top view illustrating the relative arrangement of the developing roller and the developing solution supply tank shown in FIG. 1;
  • FIG. 3 is a fragmentary enlarged view of the developing station
  • FIG. 4 is a cross section, to an enlarged scale, taken along the line A-A of FIG. 2;
  • FIG. 5 is a cross section of developing apparatus using a roller in accordance with another embodiment of the invention.
  • FIG. 6 is a schematic cross section showing a modifcation of the apparatus according to the invention in which a cleaning member is added to the developing roller;
  • FIGS. 7, 8 and 9 are views illustrating other examples of the cleaning member.
  • a sheet I to be developed having an electrostatic latent image formed thereon, as a result of exposure to radiation or by stylus recording, is fed, with its image surface located downside, by a pair of upper and lower feed rollers 20, 2b into a developing apparatus 3.
  • the developing apparatus 3 comprises a developing solution supply tank 4; a developing roller 5 located adjacent to the tank 4, a pair of guide plates 70, 7b constraining the sheet 1 fed into the developing apparatus 3 so as to bring its lower surface, which is the surface to be developed, into contact with a layer of developing solution 60 to be formed on the upper periphery of the developing roller 5; another guide plate 9 for conveying the developed sheet toward a pair of upper and lower delivery rollers 80, 8b; and a reservoir 10 of developing solution disposed below the supply tank 4 and the developing roller 5.
  • the developing solution supply tank 4 is formed of a trough-shaped vessel and extends transversely to the direction of travel of the sheet 1, with its top and its side wall adjacent to the developing roller being open.
  • a developing solution 6 contained in the reservoir 10 is pumped up into the supply tank 4 by means of a pump 11 and piping 12, both shown in phantom lines.
  • the pumped developing solution is drawn out of the tank 4 by the rotating developing roller 5 to form a layer of developing solution 60 on the upper periphery thereof; the roller 5 being rotated clockwise, that is, in the direction of travel of the sheet I to be developed, with a peripheral speed V which is from two to four times the feed rate V of the sheet 1.
  • the surface lu to be developed of the sheet I fed into the apparatus is brought into contact with the layer of developing solution 6a thus formed for the purpose of developing by the developing solution 6.
  • the developing roller 5 which draws the developing solution 6 from the supply tank 4 is formed of a material such as aluminium, stainless steel of the like, and is positioned partly received within the open side wall of the supply tank 4 as shown in FIGS. 1 and 2, with its shaft 50 being connected with a drive source, not shown, to be driven for clockwise rotation as indicated by an arrow in FIG. 1.
  • the multiple threads 5b have a lead angle a which is defined as:
  • thread grooves having a suitable lead angle a carry the developing solution to the surface to be developed in a region from its supply side across the effective area for development is maintained covered with a fresh supply of developing solution.
  • a roller without a groove or a developing roller having grooves running parallel to the axis of rotation is used to cause the formation in the area of contact between the sheet to be developed and the film of developing solution on the roller, from a sump of used developing solution or non-uniform distribution of fresh and used developing solutions, which prevents a supply of fresh developing solution from being maintained.
  • a supply of fresh developing solution 6 is maintained across the surface In to be developed of the sheet 1 for the purpose of developing.
  • the developed sheet is conveyed on the guide plate 9 and discharged externally of the apparatus by means of the delivery rollers 8a, 8b.
  • the developing solution 6 which has been drawn out of the supply tank 4 by the developing roller 5 falls downwardly with the rotation of the roller, subsequent to the formation of the layer of developing solution 6a on the upper periphery thereof, and is received into the reservoir 10.
  • the roller has an outer diameter of about 25 mm and is formed with multiple thread grooves 5b which comprise l 10 threads with a lead length of 132 mm and a pitch (width of groove) of 1.2 mm and with the angle of thread of 60.
  • the lead angle amounts to about 60, and when the ratio of V to V is chosen to be a value in a range from 2 to 4, the effective length L of the developing station becomes nearly 3 to 5 mm.
  • the normal circular pitch or the pitch determined in the AA plane shown in FIG. 2, of the multiple thread grooves 5b has a value of 0.6 mm (FIG. 4).
  • the direction in which the developing roller 5 is rotated is chosen coincident with the direction of travel of the sheet to be developed, as indicated by an arrow b in FIG. 2.
  • FIG. 5 shows another embodiment of the invention.
  • the sheet 1 to be developed is fed, with its image surface located down side, by a pair of upper and lower feed rollers 20, 2b, and guided by a guide plate 16 into a developing apparatus 13.
  • the developing apparatus 13 comprises a developing solution supply tank 14, a developing roller 5 located adjacent to the tank 14, and an upper guide plate 17 which constrains the sheet 1 fed into the apparatus so as to bring its lower surface or the surface to be developed into contact with the developing solution.
  • the developing solution supply tank 14 is in the form of a trough-shaped vessel and extends in a direction perpendicular to the direction of travel of the sheet I, with its top being open and covered by an apertured plate 18.
  • the apertured plate 18 is formed with a multiplicity of small apertures 18a having a diameter on the order of 1 mm, with a density of ID to 30 per square centimeter. In the present example, the density is chosen as 25 per square centimeter.
  • the supply tank 14 is supplied with a developing solution from a reservoir 10 of developing solution by means of a pump 1 l, and the developing solution supplied by the pump 11 fills the supply tank 14 and is caused to flood through the apertures 18a in the apertured plate 18 to the top thereof.
  • a developing roller 5 Located adjacent to the supply tank 14 is a developing roller 5, similar to the one described above, which is formed with multiple threads 5b having a suitable lead angle a
  • the roller 5 is rotated in the direction of an arrow u at a higher speed, for example, 2.5 times higher than the feed rate of the sheet I fed into the developing apparatus 13.
  • a delivery roller 19 is disposed beyond the roller 5 as viewed in the direction of travel of the sheet 1.
  • the guide plate 17 is positioned to cover the supply tank 14, developing roller and dclivery roller 19, and is formed with :1 depending portion 17(- which extends downwardly toward the supply tank 14 and another depcnding'portion 17d which extends downwardly'toward the space between the developing 5 roller 5 and the delivery roller 19.
  • These depending portions 17c and 17d serve to press down the rear surface of the sheet so as to bring its surface to developedinto Contact with the developing so lgtion.
  • the developing solution 6 fills the tank 14 and is caused to flood through the apertures 18a to the upper side of thelaperiured plate IBwThisfloOding deyeloping solution isdrawn by thevperiphery of the de-- veloping roller 5 which is rotating at a high speed to, form a layer of developing solution 6a on the periphery thereof.
  • Tl'ie developing solution after cont aqting sheet 1 falls down the periphery of the roller- 5 and is collcct'ed in the rese i'voir It).
  • the developing solution 6 is subjected to circulation along a path comprising" the reservoir [0, pump 11, supply tank 14, small apertures [8a. the periphery of the developing roller 5 and back to the reservoir 10.
  • the developing solution is sufficiently stirred when it is supplied into the supply tank 14 by the pump 1].
  • the sheet 1 is fed with its image surface disposed downwardly, into the developing apparatus 13. the upper surface of the leading edge of the sheet is initially constrained by the depending portion 17c to thereby bring the surface to be developed of the sheet I into contact with the developing solution which has flooded through the small apertures 180, the leading edge is then fed toward the developing roller 5.
  • the surface to be developed moves into contact with the layer of developing solution 6a formed on the periphery of the developing roller 5, and after passing thercover is fed toward the delivery roller 19.
  • the developing solution is supplied to only one surface of the sheet that is, the surface to be developed
  • the depending portion [7d of guide plate 17 prevents it from lifting up, so that the sheet 1 assumes a suitable configuration in which it is pressed down by the depending portions 170 and 17d during the time of travel through the apparatus with its surface to be developed maintained in contact with the layer of developing solution 6a formed on top of the developing roller as well as with the body of the developing solution which has flooded through the aperturcd plate 18.
  • the developed sheet is discharged externally of the apparatus by a pair of upper and lower discharge rollers 81:. 8b.
  • the developing roller 5 is forced to rotate with a peripheral speed which is several times the feed rate of the sheet I, while the developing solution moves at substantially the same speed as the feed rate of the sheet 1.
  • the arrangement is such that the developing solution once supplied to the surface la to be developed of the sheet 1 falls off the developing roller 5 as it rotates and is collected by the reservoir [0.
  • a portion 6b (see FIGS 1 and 6) of the used developing solution or which should normally drop into the reservoir 10 tends to continue rotating with the dcveloping roller without being released from the periphcry thereof thus undergoing acirculation around the periphery of the roller 5.
  • Such circulation results in a reduced toner concentration in the developing solution supplied to the surface' la to be developed. since it has once been used in the developin gprocess before being brought into contact with the surface to be developed. While such circulation is undesirable, it is similarly undesirable when the developing solution mixed with a tonerpowder isin a still condition since a sufficient de veloping effect cannot be achieved for the later half of the sheet because the amount of toner in the developing solution placed in contact with the latent image becomes insufficient for the later half.
  • the developing apparatus shown comprises a developing solution supply tank 24 which iscovered at its top by an apertured plate 18 and has an open side adjacent to the developing roller 5, the roller 5 being partly received in the tank-24; That portion 6b of the'used developing solution which remains attached to the periphery of the roller 5 is scraped off by a cleaning member 20 which is located within the supply tank 24.
  • the cleaning member 20 comprises a brush and its base 20a is retained within a support 24b which is formed such as by folding the bottom plate 24a of the tank 24 into a U-shaped cross section.
  • the free end of the cleaning member 20 extends into the developing solution 6 within the supply tank 24, and its forward end abuts against the periphery of the developing roller 5 in the interior of the supply tank 24.
  • the portion 6b of the used developing solution which goes around the periphery of the developing roller 5 can be scraped off by the forward end 20b of the brush or cleaning member 20 before it reaches the layer of developing solution 6a formed on top of the developing roller 5, whereby the roller periphery is cleaned.
  • the layer 6a on the roller periphery is formed by a supply of fresh developing solution which passes over the forward end 20b of the brush and through the apertured plate 18.
  • FIG. 7 shows another embodiment of the cleaning member 20 which comprises a film 20A of polyester such as Mylar (registered trademark) or the like.
  • the base 20Aa is mounted on a suitable support member 24b, and the forward end 20Ab is held in abutment against the periphery of the developing roller 5.
  • the forward end 20Ab of the cleaning member 200 be formed with a number of cuts 20Ac just in the manner of a brush, as shown in FIG. 8, in order to ensure its abutment against the periphery of the developing roller which is provided with thread grooves 5b for the purpose of drawing the developing solution.
  • the cleaning member 20, 20A is disposed within the supply tank 24, it may be located immediately beyond the point at which the developing solution falls off the roller periphery, as viewed in the direction of rotation of the roller,
  • the forward end 20Ab (20b) of the cleaning member 20A (20) may be held abutting against the developing roller 5 in a direction opposite to the direction of rotation thereof, as shown in FIG. 9.
  • the base 20Au (20a) of the cleaning member 20A (20) is mounted on the outside of the bottom plate 24a of the supply tank 24, and its forward end 20Ab (20b) may be held in abutment against the periphery of the developing roller in a direction opposite to the direction of rotation of the roller. In this manner, the used developing solution can be scraped off by the cleaning member, thereby enabling a supply of fresh developing solution to be maintained against the surface to be developed.
  • a developing apparatus for use at the developing station in wet-type electrophotographic copying machines comprising:
  • a developing roller means disposed at the developing station and adjacent said tank with the peripheral surface thereof forming at least a part of a wall of said tank, for receiving developing solution from said tank on its peripheral surface and transferring it to the surface of a sheet fed thereby, said roller means rotating at a peripheral speed greater than the speed at which a sheet to be developed is fed thereby, and said peripheral surface of said roller means being formed with a series of threads having a lead angle a in accordance with the relationship:
  • L is the efl'ective length of the developing station
  • b is the thread pitch
  • V is the speed at which a sheet to be developed is fed by said roller means
  • V is the peripheral speed of said roller means.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Wet Developing In Electrophotography (AREA)
  • Color Electrophotography (AREA)
US410988A 1972-11-13 1973-10-30 Electrophotographic developing apparatus using developing roller Expired - Lifetime US3905332A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP47113648A JPS5143783B2 (enrdf_load_stackoverflow) 1972-11-13 1972-11-13

Publications (1)

Publication Number Publication Date
US3905332A true US3905332A (en) 1975-09-16

Family

ID=14617570

Family Applications (1)

Application Number Title Priority Date Filing Date
US410988A Expired - Lifetime US3905332A (en) 1972-11-13 1973-10-30 Electrophotographic developing apparatus using developing roller

Country Status (4)

Country Link
US (1) US3905332A (enrdf_load_stackoverflow)
JP (1) JPS5143783B2 (enrdf_load_stackoverflow)
DE (2) DE2354996A1 (enrdf_load_stackoverflow)
GB (1) GB1434296A (enrdf_load_stackoverflow)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3993024A (en) * 1975-12-05 1976-11-23 Xerox Corporation Filament wound ink applicator roll
US3993023A (en) * 1975-12-05 1976-11-23 Xerox Corporation Coated filament wound ink applicator roll
US3999511A (en) * 1974-05-28 1976-12-28 Hoechst Aktiengesellschaft Apparatus for developing electrophotographic materials
US4018187A (en) * 1976-06-30 1977-04-19 International Business Machines Corporation Grooved magnetic brush roll
US4389113A (en) * 1980-05-15 1983-06-21 Ricoh Company, Ltd. Improved developing device for two-color electrophotographic copying apparatus
US5078088A (en) * 1989-10-11 1992-01-07 Olympus Optical Co., Ltd. Roller type liquid developing apparatus

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2176835A (en) * 1936-05-25 1939-10-17 United States Gypsum Co Method of saturating
US3179536A (en) * 1961-05-19 1965-04-20 Kimberly Clark Co Method and apparatus for coating paper
US3203395A (en) * 1963-06-14 1965-08-31 Addressograph Multigraph Apparatus for developing electrostatic images
US3245381A (en) * 1961-04-19 1966-04-12 Agfa Ag Developing apparatus
US3301156A (en) * 1964-01-13 1967-01-31 Peerless Photo Products Inc Processing mechanism
US3367791A (en) * 1966-07-11 1968-02-06 Addressograph Multigraph Liquid development of electrostatic images
US3384051A (en) * 1966-09-21 1968-05-21 Harris Intertype Corp Electrostatic liquid developer system
US3667428A (en) * 1969-07-01 1972-06-06 Xerox Corp Developing systems

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3088386A (en) * 1959-11-16 1963-05-07 American Photocopy Equip Co Electrophotographic photocopy machine

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2176835A (en) * 1936-05-25 1939-10-17 United States Gypsum Co Method of saturating
US3245381A (en) * 1961-04-19 1966-04-12 Agfa Ag Developing apparatus
US3179536A (en) * 1961-05-19 1965-04-20 Kimberly Clark Co Method and apparatus for coating paper
US3203395A (en) * 1963-06-14 1965-08-31 Addressograph Multigraph Apparatus for developing electrostatic images
US3301156A (en) * 1964-01-13 1967-01-31 Peerless Photo Products Inc Processing mechanism
US3367791A (en) * 1966-07-11 1968-02-06 Addressograph Multigraph Liquid development of electrostatic images
US3384051A (en) * 1966-09-21 1968-05-21 Harris Intertype Corp Electrostatic liquid developer system
US3667428A (en) * 1969-07-01 1972-06-06 Xerox Corp Developing systems

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3999511A (en) * 1974-05-28 1976-12-28 Hoechst Aktiengesellschaft Apparatus for developing electrophotographic materials
US3993024A (en) * 1975-12-05 1976-11-23 Xerox Corporation Filament wound ink applicator roll
US3993023A (en) * 1975-12-05 1976-11-23 Xerox Corporation Coated filament wound ink applicator roll
US4018187A (en) * 1976-06-30 1977-04-19 International Business Machines Corporation Grooved magnetic brush roll
US4389113A (en) * 1980-05-15 1983-06-21 Ricoh Company, Ltd. Improved developing device for two-color electrophotographic copying apparatus
US5078088A (en) * 1989-10-11 1992-01-07 Olympus Optical Co., Ltd. Roller type liquid developing apparatus

Also Published As

Publication number Publication date
DE7339370U (de) 1975-10-02
JPS4973140A (enrdf_load_stackoverflow) 1974-07-15
DE2354996A1 (de) 1974-06-06
JPS5143783B2 (enrdf_load_stackoverflow) 1976-11-24
GB1434296A (en) 1976-05-05

Similar Documents

Publication Publication Date Title
US3368526A (en) Apparatus for developing electrostatic latent images by liquid developing system
US3678896A (en) Conveyor system
US3363530A (en) Apparatus for processing film by means of a porous web solution applicator
US5144474A (en) Perforated processing apparatus and method
US2913974A (en) Photographic material processing apparatus
US3905332A (en) Electrophotographic developing apparatus using developing roller
US6236825B1 (en) Image forming apparatus including liquid-type developing device
US3943541A (en) Liquid developing apparatus for electrophotography
US3375806A (en) Xerographic donor development apparatus
US3613701A (en) Device for cleaning developed electrostatic photographic copy sheet
US4436054A (en) Xerographic toner cleaning station
US3779206A (en) Apparatus for scraping liquid off of sheet material
US7079792B2 (en) Developing unit using a developing liquid and image forming apparatus including the same
US4451133A (en) Device for removing the developer mix from a developing station
US4102306A (en) Developing roller and rinsing device
EP0033317A1 (en) Electrophotographic apparatus providing output from a typesetter
US3561400A (en) Developer apparatus
US3672326A (en) Method and apparatus for applying liquid developer to copy sheets
US3949703A (en) Self-cleaning developer applicator
US5089839A (en) Method of processing pre-sensitized lithographic printing plate and apparatus therefor
US5266994A (en) Method and apparatus for the processing of a photosensitive sheet material employing a minimum of liquid processing fluid
US3916830A (en) Magnetic brush developer
US3774574A (en) Development device for electrophotography
US3570456A (en) Liquid development apparatus for development of electrostatic images
US3727578A (en) Electrophotographic developing device using liquid