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US3292572A - Developing device - Google Patents

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Publication number
US3292572A
US3292572A US337555A US33755564A US3292572A US 3292572 A US3292572 A US 3292572A US 337555 A US337555 A US 337555A US 33755564 A US33755564 A US 33755564A US 3292572 A US3292572 A US 3292572A
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US
United States
Prior art keywords
developer
copying
roller
developing device
contact pressure
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
US337555A
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English (en)
Inventor
Brenneisen Udo
Heyl Gerhard
Marusczyk Heinrich
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.)
Bayer AG
Original Assignee
Bayer AG
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
Priority claimed from DE1963F0038775 external-priority patent/DE1272721B/de
Priority claimed from FR960075A external-priority patent/FR1387378A/fr
Application filed by Bayer AG filed Critical Bayer AG
Application granted granted Critical
Publication of US3292572A publication Critical patent/US3292572A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • G03G15/102—Apparatus for electrographic processes using a charge pattern for developing using a liquid developer for wetting the recording material for differentially wetting the recording material
    • 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
    • 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
    • G03G15/22—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20
    • G03G15/28—Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups G03G13/02 - G03G13/20 in which projection is obtained by line scanning

Definitions

  • the developing device In known electrophotographic copying apparatus with a built-in developing device for sheetwise development of copying material, the developing device is constantly in the operative state, i.e. during the whole time that the copying apparatus is switched on.
  • the means arranged along the path of the copying material and influenced by it may comprise an electric switch or a light barrier arranged in front of the point where the material is developed and an arrangement which renders the developing device operative with some delay after the switch device has been actuated, and the developing device may be returned to the inoperative condition by a time switch arrangement formed, for example, by a gearing and having preferably an adjustable switching time, or alternatively the device may be returned to the inoperative condition by the means controlled by the copying material, in dependence upon the length of the format of the copying material.
  • the developing device comprises a developer roller for applying developer to the copying material as well as a guide and/or contact pressure roller situated opposite the developer roller, one of which is displaceably mounted.
  • the contact pressure roller may be displaceable transversely to the path of the copying material by means of slides which are controlled by cam plates.
  • the cam plates may be connected to a drive motor through a magnetic clutch, the above-mentioned switch being then connected into the circuit of the magnetic clutch.
  • Another switch controlled by the slides may be connected in parallel with the first switch.
  • the contact pressure roller may be arranged on rotatably mounted levers which are displaceable, for example by means of an electromagnet into the circuit of which the switch influenced by the copying material is to be connected.
  • the contact pressure roller may be coated with a layer of conductive rubber.
  • the developer roller and the device for controlling the contact presure roller and/ or the paper transporting means of the developer device may be connected to a common drive shaft.
  • the developing device together with the container for developer, the developer roller and the contact pressure roller and the device for controlling one of these rollers may form a separate unit, preferably arranged in a housing, replaceably mounted in the copying apparatus.
  • the developing device according to the invention not only has the advantage of using the developer extremely economically but also has the further considerable advantage that the copying material can be supported on Patented Dec. 20, 1966 the rear surface at the point where it is developed without the support receiving any developer during the intervals between the passage of successive sheets of copying paper. Since no developer is applied to the support, there is no risk of developer being accidentally applied to the rear surface of the copying material in front of the support.
  • FIG. 1 is a longitudinal section through an electrophotographic office copying apparatus
  • FIG. 2 shows on a larger scale the developing device of the apparatus of FIG. 1, with the wall of the housing removed,
  • FIG. 3 is a plan view, partly in section, of part of the apparatus of FIG. 2 and FIG. 4 shows part of a further embodiment of the developing device.
  • the electrophotographic ofiice copying apparatus shown in FIG. 1 is an optical continuous copying apparatus in which the original to be copied and the copying material pass at the same speed through an illumination station and an exposure station respectively during the exposure process.
  • the original is exposed episcopally and copied stripwise on to the copying material to the scale 1:l.
  • the apparatus shown in FIG. 1 comprises a housing 1 in which all the parts of the copying apparatus are arranged.
  • a housing 1 At one end wall 2 of the housing 1 is an inlet slot 3 for introducing the original to be copied, and situated adjacent to this slot is the illumination station comprising a lower guide plate 4 and an upper, light permeable contact pressure plate 5.
  • the illumination station On leaving the illumination station, the original is guided by a U-shaped guide plate 6 to an outlet slot 7 in the end wall 2 through which it leaves the housing 1.
  • the pairs of conveyor rollers 8, 9 and 10, 11 serve to convey the original through the illumination station.
  • a container 13 which can be closed in a light-proof manner by a cover 12 which can be folded back.
  • a leafing device 15 known per se and therefore shown only diagrammatically in FIG. 1 moves the uppermost sheet of the stack 14 into a gap 16 behind which are curved guide elements 17 with two pairs of conveyor rollers 18, 19 and 20, 21 through which the sheet of copying paper is carried below the roller pair 20, 21 to a charging chamber 22 which contains spray wires 23 connected to high voltage.
  • the sheet of copying paper On leaving the chamber 22, the sheet of copying paper is gripped by a pair of conveyor rollers 24, 25 which conveys the sheet to the exposure station consisting of a vertical guide plate 26 and a light permeable contact pressure plate 27.
  • the sheet of copying paper leaving the exposure station is carried by a pair of conveyor rollers 28, 29 to an electropho-tographic developing device arranged in a housing 39 having an inlet slot 31 and an outlet slot 32 for the copying paper and forming a unit to be more fully described further down.
  • the sheet of copying paper After passing through the developing device and leaving the housing 39 through the outlet gap 32, the sheet of copying paper reaches a receiver 33 arranged below the inlet and outlet slots 3, 7 for the original in the end wall 2.
  • the housing 1 further contains a preferably tubular source of light 34 and a reflector 35 for illuminating the original passing through the illumination station 4, 5 and a deflecting mirror 36 and an objective 37 which makes a stripwise, non-reversed copy of the original passing through the illumination station on to the copy-.
  • the shafts of the above mentioned conveyor rollers situated in the path of the original and of the copying paper are rotatably mounted in side plates (no-t shown) and are driven together and at the same peripheral speed by electric motors (also not shown) by way of suitable drive means, e.g., chains or V-belt drives.
  • suitable drive means e.g., chains or V-belt drives.
  • FIGS. 2 and 3 show in more detail a developing device which can be replaced as a whole by opening a flap 38 in the housing 1.
  • This developing device operates on a principle based on the different wetting, depending on the charge, of a charge image produced on the photoconductive layer of the copying paper, by a preferably aqueous dyestuff solution.
  • the opposite side walls 39, 40 of the housing 30 are in the form of side plates on which the individual parts of the developing device are mounted.
  • two guide plates 41, 42 with vertical slots are arranged through which the spring operated probing lever 43 of a microswitch 44- extends.
  • a pair of conveyor rollers 45, 46 Situated below the guide plates 41, 42 is a pair of conveyor rollers 45, 46 the shafts 47, 48 of which are rotatably mounted in recesses of the side walls 39, 40 of the housing 30, and a curved guide plate 49 and, adjacent thereto, conveyor bands for the copying paper.
  • These conveyor bands enclose three grooved rollers 50, 51, 52 which have several parallel endless conveyor belts 53, 54 inserted in the grooves.
  • a container 56 provided with an inlet connection (not shown) and containing the developer fluid formed by a dye-stuff solution is mounted on a plate of the housing 30.
  • the developer solution is delivered by an electrically driven pump 57 and a pipe 58 into a developer trough 59 in which an overflow tube 60 connected to the container 56 keeps the liquid level constant.
  • an outflow tube 61 of smaller cross-section is provided for emptying the developer trough 59 when the pump 57 is inoperative.
  • An application roller 62 which is in frictional connection with the developer roller proper 63 arranged along the path of the copying paper between the conveyor rollers 4-5, 46 and the guide plate 49 or which is driven by the shaft 64 by way of a pair of gear wheels dips into the developer liquid in the trough 59.
  • the levers 69 are rotatable about the shaft 70 which is fixed to the housing and they are under the action of tension springs 71.
  • a contact pressure roller 72 Opposite the developer rollers 63 is a contact pressure roller 72 whose shaft 73 together with its bearings 74 is displaceable in horizontal slots 75 of the side walls 39, 40 of the housing 30.
  • slides 76 On both sides of the contact pressure roller 72, slides 76 connected together through a web 77 are rota-tably mounted on the shaft 73.
  • the slides 76 are provided with pins 78 which are also displaceable in horizontal slots 79 in the side walls 39, 40 of the housing 30.
  • cam plates 80 mounted on a common shaft 81. This shaft projects through horizontal slots 82 of the slides 76 and is rotatable in bearings 83 of the side walls 39, 40 of the housing 30.
  • the cams 84 of the cam plates 80 cooperate with plates 85 which are fixed to the pins 78 of the slides 76.
  • Two armed levers 86 which are rotatable about the spindle 87 fixed to the housing and are under the action of tension springs 88 act on the bearings 74 of the shaft 73 of the contact pressure roller 72. These springs tend to press the roller 72 against the developer roller 63.
  • the driving arrangement of the developing device comprises a drive shaft 89 which is positively connected to the electric motor supplying the whole apparatus and which carries two gear wheels 90, 91. While the gear wheel 90 meshes with a gear wheel 92 arranged on the shaft 64 of the application roller 62, the gear wheel 91 meshes with a gear wheel 93 mounted on a shaft 94.
  • a gear wheel 95 driving the pair of conveyor rollers 45, 46 is rigidly mounted on the shaft 94 and a further gear wheel 96 is mounted to be loosely rotatable on this shaft.
  • the gear wheel 96 may be positively connected to the shaft 94 through a magnetic clutch 97, which is known and only shown diagrammatically, the clutch plates of which receive voltage through slip rings (not shown).
  • a gear wheel 98 which is fixed to the shaft 81 of the cam plates 80 meshes with the gear Wheel 96.
  • the spring loaded probing lever 99 of a microswitch 100 lies in contact with the plate 85 of one of the slides 76.
  • the microswitches 44, 100 are connected in parallel into the circuit of the magnetic clutch 97.
  • the shaft 89 may also be used for driving the conveyor bands 53, 54.
  • a drying apparatus may be arranged above the conveyor band 54.
  • the apparatus according to the invention which is shown in FIGS. 2 and 3 in the starting position with the switches 44, 100 open, operates as follows:
  • the driving motor of the apparatus is switched on by closing a main switch so that the conveyor rollers as well as the application roller 62 with the developer roller 63 and the squeezing roller 67 begin to rotate while the magnetic clutch 97 is without current.
  • the paper delivery device 15 is switched on by a microswitch (not shown) arranged in the inlet duct to execute a working stroke so that the uppermost sheet of the stack 14 of co ying paper is carried to the inlet slot 16 and from there to the charging station 22 and the exposure station 26, 27.
  • a charge image is produced which corresponds to the image of the original passing through the illumination station 4, 5.
  • the conveyor rollers 28, 29 carry the exposed sheet 101 of copying paper (FIG. 2) into the inlet slot 31 of the developing device 30.
  • the sheet 101 of copying paper passes between the guide plates 41, 42 and its front edge pushes the probing lever 43 of the microswitch 44 aside by swinging in the anticlockwise sense, whereby the microswitch 44 is closed, the magnetic clutch 97 comes into operation and the cam plates 80 begin to rotate in the clockwise sense.
  • the rear edges of the cams 84 leave the plates 85 of the slides 76 at the precise moment when the front edge of the sheet of copying paper 101, which is gripped between the conveyor rollers 45, 46, has reached the developer roller 63.
  • the spring loaded probing lever 99 of the microswitch 100 which bears against the plate 85, is also displaced in a clockwise direction and thus closes the switch 100, so that the magnetic clutch 97 remains energised even when the rear edge of the sheet 101 of copying paper has passed the probing lever 43 of the microswitch 44 and the latter returns to its starting position.
  • the speed of rotation of the cam plates 80 and the length of the format of the sheet 101 of copying paper are so adjusted to each other that the cam plates 80 have just completed a full rotation when the rear edge of the sheet 101 reaches the developer roller 63 and the contact pressure roller 72.
  • the cams 84 again make contact with the plates 85 of the slides 76 and push the slides back into the starting position against the action of the springs 88, the contact pressure roller 72 being then again lifted away from the rear surface of the copying paper.
  • the microswitch 100 is thereby actuated through the probing lever 99.
  • the clutch 97 is deenergised, the contact pressure roller remains raised in the starting position for the next copy.
  • the developing device described in FIGS. 2 and 3 is suitable for apparatus used for treating copying papers of a certain length of format.
  • the cam plates 80 together with the cams 84 and the plates 8'5of the slides 76 form a time switch device in which, if the cam plates 80 are made of two parts in the form of double plates displaceable relatively to each other, the switching time can be varied by varying the effective overall width of the cam 84 and can thus be adapted to copying papers of different lengths of format.
  • an electrical time switch device of known construction may be used.
  • the levers 102 are rotatable about a shaft 103 fixed to the housing and are under the action of tension springs 104 which act on the upper ends of these levers. Further, an electromagnet 105 is provided whose armature 106 is connected by the intermediate member 107 to a rod 108 which is arranged between the lower ends of the levers 102.
  • the microswitch 44 is in this case connected into the circuit of the pull magnets 105.
  • the microswitch 44 applies a voltage to the pull magnets 105 after a brief delay after the probing lever 43 has been actuated by the front edge of the copying paper introduced into the slot 31, so that the magnet presses the contact pressure roller 72 on to the developer roller 63 against the force of springs 104 at the instant when the front edge of the copying paper continuously carried by the pair of conveyor rollers 45, 46 is situated between the rollers 63, 72.
  • rollers 63, 72 must be insulated from each other. This may most simply be done by making the side walls 39, 40 of the housing 30 of insulating material.
  • the voltage may suitably be so applied that the contact pressure roller 72 which touches the conductive underlay of the copying paper is earthed while a voltage is applied to the rollers 62, 63 which are wetted with the developer liquid.
  • a protective resistor must be connected into the voltage supply to limit the current.
  • the contact pressure roller 72 may advantageously be coated with a layer of conductive rubber. The specific resistance of the rubber may be so chosen that the layer of rubber takes over the role of protective resistor.
  • the squeezing roller 67 and the conveyor roller 46 are preferably also rubberised.
  • the cylindrical surface of the developer roller 63 is provided with a winding 109 of thin metal wire.
  • the wire has a thickness of 0.05 to 0.5 mm., preferably 0.2 mm.
  • the developer roller 63 may be surface profiled by covering it with a fine mesh (size of mesh between 20 and 200p.) of metal wire or monofilar textile threads or with a layer a few mm. thick or porous material such as felt, finely porous rubber or foam plastic.
  • the surface profiling of the developer roller 63 may further more also be achieved in the form of cording or a threading worked into the surface or small cup-shaped recesses. If, according to the above proposal, a threading is worked into the surface of the developer roller 63, this may have a pitch of, for example, 0.05 to 0.5 mm., preferably 0.2 mm. and a depth of, for example, 0.37 mm.
  • the pull magnet 105 may be used for displacing the slides 76 in FIGS. 2 and 3 instead of the levers 102 in FIG. 4.
  • the cam plates 80 of FIGS. 2 and 3 may also be used for controlling the levers 102 of FIG. 4.
  • control according to the invention of the contact pressure roller 72 is advantageous also when the development of the latent charge image on the copying paper is effected not by differential wetting determined by the charge but by electrophoretic, electrolytic or other means.
  • the roller 63 may be lifted by a roller or plate guiding the copying paper to the development station and may be controlled in dependence upon the passage of the copying paper.
  • This variation of the invention is advantageous particularly when developer is used in the form of powder which is applied to the photoconductive layer of the copying paper by a magnetic roller automatically controlled in dependence upon the passage of the copying paper.
  • the principle according to the invention of automatically transferring a developing device from the inoperative to the operative condition and returning it to the inoperative condition in dependence upon the passage of copying paper through it may be successfully applied also When the developer is not applied to the copying paper by rollers but sprayed on to the copying paper.
  • the switching on and off of the spray nozzles of the developing device may be controlled by the microswitch 44.
  • the conveyor bands 53, 54 together with the drying 7 apparatus not shown obviously need not necessarily be included in the housing 30 of the developing device.
  • an outlet slot would be provided at the bottom of the housing 39 below the guide plate 46 instead of the outlet slot 32.
  • control according to the invention of the developing device in dependence upon the passage of the copying material through it may be successfully used not only in electrophotographic but also in other apparatus.
  • Developing device for applying liquid developer to copying material running through it in sheets, for electrophotographic apparatus comprising a switch influenced by the copying material, said switch being arranged in the path of conveyance of said copying material in front of the developer station and being connected into the circuit of a magnetic clutch, cam plates being connected to a drive motor through said magnetic clutch, said cam plates controlling slides which are provided with a contact pressure roller arranged opposite a developer roller, said contact pressure roller being mounted so as to be displaceable transversely of the path of conveyance of the copying material by means of said slides, said developing device being returned to the inoperative condition by means controlled by said copying material in dependance upon the length of the format of said copying material.
  • Developing device comprising 0 a second switch, which is controllable by said slides, being connected in parallel with said switch.
  • Developing device according to claim 1, comprising said contact pressure roller being arranged on rotatably mounted levers.
  • Developing device comprising said contact pressure roller being coated with a layer of conductive rubber.
  • Developing device comprising said developing roller and the device for controlling the contact pressure roller and the paper transporting means of said developing device being connected to a common drive shaft.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Wet Developing In Electrophotography (AREA)
US337555A 1963-01-16 1964-01-14 Developing device Expired - Lifetime US3292572A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DEF0038773 1963-01-16
DE1963F0038775 DE1272721B (de) 1963-01-16 1963-01-16 Vorrichtung zur Entwicklung von blattfoermigem elektrophotographischem Aufzeichnungsmaterial
FR960075A FR1387378A (fr) 1963-01-16 1964-01-13 Dispositif de développement destiné en particulier aux appareils électrophotographiques

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US3292572A true US3292572A (en) 1966-12-20

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US337555A Expired - Lifetime US3292572A (en) 1963-01-16 1964-01-14 Developing device

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3368525A (en) * 1965-10-04 1968-02-13 American Photocopy Equip Co Liquid developer system for photocopy machine
FR2131601A5 (es) * 1971-03-24 1972-11-10 Ricoh Kk
US3798049A (en) * 1971-04-09 1974-03-19 H Kosche Method for the development of latent electrostatic images
US3993023A (en) * 1975-12-05 1976-11-23 Xerox Corporation Coated filament wound ink applicator roll
US3993024A (en) * 1975-12-05 1976-11-23 Xerox Corporation Filament wound ink applicator roll
US3999515A (en) * 1975-02-03 1976-12-28 Xerox Corporation Self-spacing microfield donors
US4245023A (en) * 1973-01-10 1981-01-13 Agfa-Gevaert N.V. Method for the development of electrostatic charge images
US5937258A (en) * 1997-02-28 1999-08-10 Xerox Corporation Paper conditioner with articulating back-up/transfer rollers

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US606869A (en) * 1898-07-05 macbrair
US2545905A (en) * 1944-06-17 1951-03-20 Hvde Mfg Company Paster for wallpaper machines
US2894481A (en) * 1953-06-26 1959-07-14 Metal Box Co Ltd Control devices for apparatus for applying coatings to metal sheets
US3196831A (en) * 1959-11-16 1965-07-27 American Photocopy Equip Co Developing unit for photocopy machine

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US606869A (en) * 1898-07-05 macbrair
US2545905A (en) * 1944-06-17 1951-03-20 Hvde Mfg Company Paster for wallpaper machines
US2894481A (en) * 1953-06-26 1959-07-14 Metal Box Co Ltd Control devices for apparatus for applying coatings to metal sheets
US3196831A (en) * 1959-11-16 1965-07-27 American Photocopy Equip Co Developing unit for photocopy machine

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3368525A (en) * 1965-10-04 1968-02-13 American Photocopy Equip Co Liquid developer system for photocopy machine
FR2131601A5 (es) * 1971-03-24 1972-11-10 Ricoh Kk
US3798049A (en) * 1971-04-09 1974-03-19 H Kosche Method for the development of latent electrostatic images
US4245023A (en) * 1973-01-10 1981-01-13 Agfa-Gevaert N.V. Method for the development of electrostatic charge images
US3999515A (en) * 1975-02-03 1976-12-28 Xerox Corporation Self-spacing microfield donors
US3993023A (en) * 1975-12-05 1976-11-23 Xerox Corporation Coated filament wound ink applicator roll
US3993024A (en) * 1975-12-05 1976-11-23 Xerox Corporation Filament wound ink applicator roll
US5937258A (en) * 1997-02-28 1999-08-10 Xerox Corporation Paper conditioner with articulating back-up/transfer rollers

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Publication number Publication date
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