US3559620A - Conveyance of electrically charged sheets - Google Patents

Conveyance of electrically charged sheets Download PDF

Info

Publication number
US3559620A
US3559620A US753297A US3559620DA US3559620A US 3559620 A US3559620 A US 3559620A US 753297 A US753297 A US 753297A US 3559620D A US3559620D A US 3559620DA US 3559620 A US3559620 A US 3559620A
Authority
US
United States
Prior art keywords
sheet
rollers
roller
driving
electrically conductive
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
US753297A
Other languages
English (en)
Inventor
Martin R P Seib
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Application granted granted Critical
Publication of US3559620A publication Critical patent/US3559620A/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
    • 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
    • G03G15/11—Removing excess liquid developer, e.g. by heat

Definitions

  • the stainless steel rollers may be maintained at a high potential of the same polarity of the toner particles used in the developer, in which case there is a reduction in the number of particles, picked up by the insulating rollers, which is returned to the sheet.
  • This invention relates to conveying means for electrically charged sheets of electrophotographic paper.
  • an electrostatic charge is formed in a photoconductive layer on one surface of an electrophotographic paper and an optical image of apredetermined object is focused on to the charged surface by optical projection means.
  • the charge leaks away from those areas of the charged surface which are subjected to electromagnetic radiation and an electrostatic charge image, corresponding to the photographic image projected by the optical projection means, is thereby formed.
  • the sheet is suitably passed through a developing bath containing a liquid suspension of black, charged toner particles in an insulating liquid such as paraffin.
  • the charged particles adhere to the charged or uncharged areas of the sheet, according to their polarity, and thereby produce a positive or negative print of the original photographic image.
  • Fixing is effected by drying the sheet to remove excess paraffin.
  • the present invention consists in means for conveying a charged sheet of electrophotographic paper from liquid developer means to drying means comprising cooperating driving elements which are adapted to engage respective opposite sides of the sheet and, in driving the sheet along a predetermined path, to remove liquid developer therefrom, each driving element having the sheet engaging surface thereof formed of electrically insulating material, wherein the driving element which engages a photoconductive layer of the sheet is engaged at a location spaced from the path of the sheet by an electrically conductive element, and means are provided for maintaining the electrically conductive element at a predetermined electrical potential, whereby the electrically conductive element reduces the amount of electrical charge, transferred to the associated driving element from the charged sheet, which is transferred back from the driving element to a part of the sheet subsequently engaged by the driving elements.
  • the conveying means shown in the drawing form part of an electrophotographic apparatus which includes a store for sheets of electrophotographic paper, means for dispensing sheets individually from the store to a charger in which a charge is induced in a photoconductive layer of the sheet, and driving means 1 for conveying sheets from the charger to a viewing table 3.
  • a sheet is exposed to light from an optical projection system of the apparatus and an electrostatic image is formed on the charged photoconductive layer.
  • the driving means 1 convey the sheet to a liquid developer 5 and from the developer the sheet is driven by conveying means 7 to fixing and drying means 9.
  • the table 3 is upwardly and rearwardly inclined from front to rear of the apparatus, from right to left as seen in the drawing.
  • the driving means 1 are mounted on the table 3 and include an upper driving roller 10 and a series of endless belts 11 which engage the roller 1 and further rollers, not shown in the drawing, and which have their upper runs in flatwise engagement with the top of the table.
  • An exposed sheet of paper is engaged between the belts 11 and a guide sheet 13 of polytetrafluorethylene as it leaves the table 3 and is directed downwardly to a developer tray 15 of the above-mentioned developer 5.
  • the tray 15 is arcuate in section and has the base thereof formed with upstanding ribs 17.
  • a liquid suspension of black, positively charged toner par ticles in paraffin is pumped from a tank (not shown) to a spray bar 19 above the tray 15, from which the liquid is directed on to a sheet entering the tray. Excess liquid is continuously decanted from the tray 15 to the tank.
  • the conveying means 7 On the outlet side of the tray 15 are the conveying means 7 for driving a sheet from the tray to the fixing and drying means 9.
  • the conveying means 7 include a series of four rollers 21, 23, 25 and 27 each of which is journaled at opposed ends thereof in respective mounting plates 29.
  • Mounting plates 29 are secured to a shaft 31 which extends parallel to the axes of rollers 21 to 27 and rests in slots 33 in respective supporting brackets 35.
  • roller 23 is coupled via a clutch mechanism (not shown) to a chain 37 which is driven by an electric motor (also not shown).
  • the conveying means 7 can therefore be removed from the apparatus to provide access to the tray 15 by releasing the clutch mechanism and lifting the shaft 31 out of the slots 33.
  • Each of the rollers 23 and 25 consists of a metal spindle which extends between the mounting plates 29 and is provided with a covering of polyurethane over a major part of its length.
  • a sheet of electrophotographic paper emerging from the tray 15 is engaged between rollers 23 and 25 and is driven thereby to the fixing and drying means 9.
  • Roller 21 is disposed vertically above the roller 23 and engages the latter at a location spaced from the path of a sheet from the tray 15 and diametrically opposed to the location at which roller 23 is engaged by roller 25.
  • Roller 27 is disposed vertically beneath the roller 25 and engages roller 25 at a location diametrically opposed to its engagement with roller 23.
  • Each of the rollers 21 and 27 is formed of stainless steel and is maintained at earth potential by virtue of the electrically conductive connection which extends via the bearings for the roller, mounting plates 29 and the brackets 35 to the earthed framework of the apparatus.
  • an electrostatic image is formed in a photoconductive layer of a sheet on the table 3 and the driving means 1 are then energized to drive the sheet downwardly towards the tray 15.
  • the leading edge of the sheet engages the ribs 17 on the base of the tray and is guided downwardly and rearwardly of the apparatus, into the liquid developer, and then upwardly and rearwardly towards the rollers 23 and 25.
  • an electrically conductive base layer of the sheet is supported in the ribs 17.
  • Means for conveying a charged sheet of electrophotographic paper from liquid developer means to drying mcans comprising cooperating driving rollers which are adapted to engage respective opposite sides of the sheet and. in driving the sheet along a predetermined path, to remove liquid developer therefrom, each driving roller having the sheet engaging surface thereofformed of electrically insulating material.
  • each driving roller which engages a photoconductive layer of the sheet being engaged at a location spaced from the path of the sheet by an electrically conductive roller, and means for maintaining the electrically conductive rollers at a predetermined electrical potential, whereby the electrically conductive roller reduces the amount of electrical charge, transferred to the associated driving roller from the charged sheet, which 5 is transferred back from the driving roller to a part of the sheet subsequently engaged by the driving rollers.
  • Conveying means as claimed in claim I wherein means are provided for maintaining the or each electrically conductive roller at a high electrical potential of the same polarity as the polarity of the toner particles on the sheet, whereby there is a reduction in the number of toner particles, transferred to the or each associated driving roller from the charged sheet, which are transferred back to a part of the sheet subsequently engaged by the driving rollers.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Fixing For Electrophotography (AREA)
  • Cleaning In Electrography (AREA)
  • Wet Developing In Electrophotography (AREA)
US753297A 1967-04-25 1968-08-16 Conveyance of electrically charged sheets Expired - Lifetime US3559620A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB3386468 1967-04-25
US75329768A 1968-08-16 1968-08-16

Publications (1)

Publication Number Publication Date
US3559620A true US3559620A (en) 1971-02-02

Family

ID=26262054

Family Applications (1)

Application Number Title Priority Date Filing Date
US753297A Expired - Lifetime US3559620A (en) 1967-04-25 1968-08-16 Conveyance of electrically charged sheets

Country Status (2)

Country Link
US (1) US3559620A (enrdf_load_stackoverflow)
GB (1) GB1230842A (enrdf_load_stackoverflow)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4091765A (en) * 1977-02-17 1978-05-30 Vivian L. Lowthorp, Executrix of the Estate of Ernest C. Lowthorp, deceased Developing and fusing apparatus
US4218246A (en) * 1970-03-18 1980-08-19 Canon Kabushiki Kaisha Method of electrophotographic recording involving removal of excess developer liquid by corona treatment

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3155546A (en) * 1962-09-24 1964-11-03 Plastic Coating Corp Apparatus for the liquid toning of latent electrostatic images
US3202526A (en) * 1961-10-05 1965-08-24 Scm Corp Method and apparatus for liquid development of latent images
US3345925A (en) * 1963-01-03 1967-10-10 Scm Corp Electrostatic printing and developing apparatus

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3202526A (en) * 1961-10-05 1965-08-24 Scm Corp Method and apparatus for liquid development of latent images
US3155546A (en) * 1962-09-24 1964-11-03 Plastic Coating Corp Apparatus for the liquid toning of latent electrostatic images
US3345925A (en) * 1963-01-03 1967-10-10 Scm Corp Electrostatic printing and developing apparatus

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4218246A (en) * 1970-03-18 1980-08-19 Canon Kabushiki Kaisha Method of electrophotographic recording involving removal of excess developer liquid by corona treatment
US4091765A (en) * 1977-02-17 1978-05-30 Vivian L. Lowthorp, Executrix of the Estate of Ernest C. Lowthorp, deceased Developing and fusing apparatus

Also Published As

Publication number Publication date
GB1230842A (enrdf_load_stackoverflow) 1971-05-05

Similar Documents

Publication Publication Date Title
US3088386A (en) Electrophotographic photocopy machine
JP3015116B2 (ja) 現像装置
US3446184A (en) Apparatus for powder development of liquid latent images
US3345925A (en) Electrostatic printing and developing apparatus
US3355288A (en) Electrostatic printing method and apparatus
DE2065817A1 (de) Elektrophotographisches kopiergeraet
US3375806A (en) Xerographic donor development apparatus
US3515855A (en) Xerographic fusing apparatus
US5023665A (en) Excess liquid carrier removal apparatus
US3709594A (en) Method and apparatus for electrostatic color printing
US4736227A (en) Liquid ink transfer system
US3559620A (en) Conveyance of electrically charged sheets
JPH0652451B2 (ja) 液体現像装置
US4731631A (en) Vertically oriented photoconductive drum
US3207050A (en) Apparatus for the production of copies
JP3023999B2 (ja) 電子写真印刷機
NL7908695A (nl) Inrichting voor het ontwikkelen van een latent elektrostatisch beeld.
JP3021069B2 (ja) 電子写真印刷機
US3441345A (en) Photocopying
US3081677A (en) Device for preparing a copy by means of latent electrostatic images
JP2809423B2 (ja) 複写機の転写装置
DE2919804A1 (de) Verfahren und einrichtung zum entwickeln eines latenten elektrostatischen bildes
US3612681A (en) Electrophotographic copying device
US3583700A (en) Conveyance of electrically charged sheets
DE2011241A1 (de) Kopiergerat