US3923391A - Electrostatic photographic copying apparatus - Google Patents

Electrostatic photographic copying apparatus Download PDF

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Publication number
US3923391A
US3923391A US399516A US39951673A US3923391A US 3923391 A US3923391 A US 3923391A US 399516 A US399516 A US 399516A US 39951673 A US39951673 A US 39951673A US 3923391 A US3923391 A US 3923391A
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United States
Prior art keywords
transfer paper
transfer
photosensitive drum
image
zone
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Expired - Lifetime
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US399516A
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English (en)
Inventor
Takaji Washio
Koichi Sasaki
Tatsuo Aizawa
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.)
Kyocera Mita Industrial Co Ltd
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Mita Industrial Co Ltd
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Publication date
Application filed by Mita Industrial Co Ltd filed Critical Mita Industrial Co Ltd
Priority to US05/570,428 priority Critical patent/US4040387A/en
Priority to US05/570,426 priority patent/US4033689A/en
Priority to US05/570,427 priority patent/US4012139A/en
Application granted granted Critical
Publication of US3923391A publication Critical patent/US3923391A/en
Anticipated expiration legal-status Critical
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    • 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
    • G03G15/70—Detecting malfunctions relating to paper handling, e.g. jams
    • 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
    • G03G15/30—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 in which projection is formed on a drum

Definitions

  • G03C /00 Said photo'sensitive drum for forming on said sensitive .
  • Field of Search H 355, R, 8, 1 1, 14, 50 material an electrostatic latent image corresponding to 355/51 66 the image of the original or a developed image corresponding to the latent image, a transfer zone for trans- [56] References Cited ferring said image to a transfer paper, and a transfer paper forwarding system for feeding the transfer paper UNITED STATES PATENTS on which the image has been transferred to a disgrztlvesnkwl. 355/3 R charge end through a desired treating Zone. u us e a 3,399,610 9/1968 Eichorn 355/8 8 Claims, 16 Drawing Figures a ill?
  • This invention relates to an improvement in electrostatic photographic copying apparatus, and specifically to an improvement in an electrostatic photographic copying apparatus of the type equipped with a rotatable photosensitive drum.
  • the conventional electrostatic photographic copying apparatus of this type generally requires a synchronization control mechanism having a complicated structure in order to expose an image of an original a photosensitive drum synchronously with the rotation of the photosensitive drum, and in order to a transfer paper synchronously with the rotation of the photosensitive drum. Furthermore, it is necessary to provide an electrical charging mechanism or an exposing section for an optical system, etc. along the circumference of the photosensitive drum. These provisions tend to increase the size of the apparatus.
  • Another object of this invention is to provide an electrostatic photographic copying apparatus in which the photosensitive drum and a transfer paper can be moved in exact synchronization with each other by a device having a relatively simple structure.
  • Still another object of this invention is to provide an electrostatic photographic copying apparatus which includes a cut length adjusting device having a relatively simple structure whereby a continuous web of transfer paper can be cut exactly according to the required copying length of the original.
  • a further object of this invention is to provide an electrostatic photographic copying apparatus which is relatively compact.
  • an electrostatic photographic copying apparatus comprising a frame member having a transparent plate on which an original to be copied is placed, a rotatable photosensitive drum having electrostatic photographic material on its periphery, an optical system for projecting an image of the original onto the surface of the photographic material, an image-forming zone disposed exteriorly of, and alongside, the periphery of said photosensitive drum for forming on said sensitive material an electrostatic latent image corresponding to the image of the original or a developed image'corresponding to the latent image, a transfer zone for transferring said image to a transfer paper, and a transfer paper forwarding system for feeding the transfer paper on which the image has been transferred to a discharge end through a desired treating zone.
  • This invention can be applied to any electro-static photographic copying machine of the type in which a photosensitive drum is provided in a machine housing and transfer paper is brought into contact with the photosensitive drum to thereby transfer the image from the photosensitive drum to the transfer paper.
  • this invention can be applied to either a copying machine of the so called original-moving, slit-exposure type in which an original to be copied is supported on a transparent plate mounted movably in the machine housing and an optical system is fixed in the housing, or the so called optical system-moving type in which an original is supported on a transparent plate fixed in the machine housing, while the optical system is moved to effect the slit exposure.
  • this invention can be applied to a copying machine of the so called static image-transferring type in which an electrostatic image is formed on the surface of a photosensitive layer of a photosensitive drum, transferred to transfer paper and then visualized, or to a copying machine of the so called toner image-transferring type in which an electrostatic image formed on the surface of a photosensitive drum is developed with a toner and the toner image is transferred to transfer paper and, if required, fixed.
  • This invention can also be applied to a copying machine of the type in which transfer paper is fed in a separate sheets or from a web-like form as withdrawn from a paper roll.
  • this invention can be applied to a copying machine of the type in which a container or cartridge of transfer paper sheets is provided on one end wall of the machine housing and transfer paper sheets are automatically fed from such container or cartridge, or to a copying machine of the type in which transfer paper sheets are manually fed into a passage for transportation of transfer paper sheets.
  • FIG. 1 is an arrangement diagram illustrating the outline of the copying machine of this invention.
  • FIG. 2 is a sectional side view in which the optical system and static image-forming zone of the copying machine of FIG. 1 are illustratively enlarged.
  • FIG. 3 is an enlarged sectional side view illustrating an embodiment of the developing apparatus usable in the copying machine of this invention.
  • FIGS. 4 and 5 are diagrams illustrating the arrangement and function of the magnet mechanism used in the developing apparatus of FIG. 3.
  • FIG. 6 is a side view illustrating the arrangement of the developing counter pole used in combination with the developing apparatus of FIG. 3.
  • FIG. 7 is a perspective view illustrating a toner supply cartridge used in the developing apparatus of FIG. 3.
  • FIG. 8-A is a simplified side view of the transfer apparatus used in the copying machine of this invention.
  • FIG. 8-B is an enlarged sectional side view of the fixation zone of the copying machine of this invention.
  • FIG. 9 is a diagram illustrating the principle of the copying machine of this invention.
  • FIG. 10 is an arrangement view of various control mechanisms used in the copying machine of this invention.
  • FIG. ll-A is an arrangement view showing the driving system of the copying machine of this invention.
  • FIG. 11-3 is a sectional view showing the system for driving the moving frame.
  • FIG. ll-C is a perspective view illustrating the restraint mechanism for the moving frame.
  • FIG. l2-A and l2-B are wiring diagrams of the electric circuit of the copying machine of this invention.
  • FIG. 1 illustrating an outline of the entire arrangeexposure mechanism '11 and the entire surface exposure mechanism 12 maybe omitted. Furthermore,
  • a photosensitive drum 6 having on the surface thereof a electrostatic photosensitive layer is rotatably mounted.
  • This photosensitive layer 5 may be any of a monolayer photosensitive plate formed by applying an inorganic photoconductor such as selenium, zinc oxide, cadmium sulfide, or cadmium selenide or an organic photoconductor such as polyvinyl carbazole, optionally together with a binder, on a substrate such as a metal plate or a paper rendered electrically conductive, a multilayer photosensitive plate formed by laminating a plurality of photoconductor layers or a sandwich-type multilayer photosensitive plate forming by inserting a photoconductor layer between an insulator layer and a conductor layer.
  • an inorganic photoconductor such as selenium, zinc oxide, cadmium sulfide, or cadmium selenide or an organic photoconductor such as polyvinyl carbazole, optionally together with a binder, on a substrate such as a metal plate or a paper rendered electrically conductive
  • a multilayer photosensitive plate formed by laminating
  • an image-forming zone 7 and a transfer zone 8 are grouped along the peripheral surface of the photosensitive drum 6.
  • the image-forming zone 7 comprises a static latent image-forming area including a preliminary electrification mechanism 9 for erasing the charge remaining on the surface of the photosensitive layer, a primary electrification mechanism 10 for charging the surface of the photosensitive layer with a specific polarity, a secondary electrification and simultaneous exposure mechanism 11 for effecting the secondary electrification while an image is being exposed on the primarily electrified photosensitive layer and an exposure mechanism 12 for exposing to light the entire surface of the secondarily electrified and imagelight-exposed photosensitive layer, and a developing area including a development'mechanism 13 for developing the electro-static latent image with a toner powder.
  • Each of the foregoing electrification mechanisms includes a corona wire on which a high voltage is applied, and the photosensitive layer is electrified by the corona discharge from this corona wire.
  • the secondary electrification and simultaneous exposure mechanism 1 1 comprises an optical passage 14 connecting the photoconductive layer 5 optically with an opening for exposing the photosensitive layer to light and a corona wire 15 in said optical passage 14, on which a high voltage is applied.
  • the voltage to be applied on the 15 of the secondary electrification and simultaneous exposure mechanism 11 may be a direct current voltage of a polarity reverse to the polarity of the primary electrification, an alternating current voltage or an asymmetric alternating current voltage.
  • the toner powder development mechanism 13 may be of any desired type such as for example, a magnetic brush type, a cascade type or a powder cloud type.
  • An optical system indicated as a whole by reference numeral 16 is provided to project an image of the original a supported on the transparent plate 2, onto the photosensitive layer 5 in the above-mentioned imageforming zone.
  • This optical system 16 comprises an opening 17 mounted in the upper portion of the housing 1 to expose the original to light, a light source 18 for illuminating the original a to be copied, a photosensitive layer-light-exposing opening 19 provided in the vicinity of the photosensitive layer 5 of the photosensitive drum in the image-forming zone 7, and a group of reflex mirrors 20, 21 and a mirror lens 22 provided to connect optically the original-light-exposing opening 17 with the photosensitive layer-light-exposing opening 19 and to form a reverse image of the original a to be copied on the photosensitive layer 5.
  • the transfer zone 8 is disposed in succession to the image-forming zone 7.
  • a passage for transfer paper b (indicated as a whole by reference numeral 23) is provided so that said passage is circum-. scribed with the photosensitive drum 6 in the transfer zone 8.
  • a transfer paper feed mechanism is mounted at the upstream end of this transfer paper passage 23.
  • a roll stand 25 supported rockably on the machine housing by means of a fulcrum 24 is mounted on the upstream end of the transfer paper passage 23, and a shaft 28 of a reel 27 is removably and rotatably mounted on a fitting recess 26 formed on the upper end of this roll stand 25.
  • a guide roller 29 and a pair of driven feed rollers 30, 30 Downstream of the reel 27, there are provided both a guide roller 29 and a pair of driven feed rollers 30, 30 provided with a roll paper feeding clutch C2 in order to introduce transfer paper from a transfer paper roll b wound on the shaft of the reel 27.
  • a pair of transfer papertransporting rollers 31, 31 which are normally driven are disposed between the feed rollers 30, 30 and the transfer zone 8, and a transfer papercutting mechanism 32 is mounted between the feed roller 30, 30 and the transfer paper-transporting rollers 31, 31'.
  • This transfer paper-cutting mechanism 32 includes a stationary blade member 33 and a rotary blade member 34.
  • the rotary blade member 34 is rotated by excitation of a cutter solenoid and cuts transfer paper b passing through the stationary blade member 33 and rotary blade member 34.
  • the position (Pl) shown in FIG. 9 and 10 for actuation of the transfer paper-cutting mechanism is the position of the upper edge of the stationary blade member 33.
  • the blade of the rotary blade member 34 is positioned on the upper side of the transfer paper passage between the feed rollers 30, 30' and the transporting rollers 31, 31' so that it does not intersect the transfer paper passage.
  • the position of the leading edge of transfer paper atthe beginning of feeding and the position for stoppage and standing-by of the leading edge of rolllike transfer paper cut are set at the position (Pl) for actuation of the transfer paper-cutting mechanism.
  • upper and lower guide plates 35a and 35'a' are disposed between the cutting mechanism 32 and feed rollers 30, 30, and another upper and lower guide plates 35b and 35b, between the cutting mechanism 32 and transporting rollers 31, 31, so that lower guide plates 35a and 35b are positioned in an almost straight line with the upper edge of the stationary blade member 33 and the upper guide plates 35a and 35b are positioned in an almost straight line with the lower edge of the rotary blade member 34 in the non-actuated state.
  • the foregoing structures make it possible to conduct the transportation and stoppage of transfer paper smoothly without occurrence of paper jamming or other troubles. Further downstream of the normally driven, transporting rollers 31, 31, there are provided upper and lower guide plates 35c and 350' to introduce transfer paper b into the transfer zone 8.
  • a paper feed mechanism for feeding a sheet-like transfer paper b is provided independently of the paper feed mechanism for feeding a roll-like transfer paper. More specifically, a paper-feeding table 51 is provided openably or removably at the end of the machine housing 1 at the upstream end of the transfer papertransporting passage 23 to feed a sheet-like transfer paper b", and at the tip of this paper-feeding table, there are mounted a paper sheet feeding opening 52 and upper and lower guide plates 35d and 35'd connected to this opening 52. A pair of paper sheet feed driven rollers 53, 53 provided with a sheet paper feed clutch C3 (shown in FIG. 11-A) are mounted downstream of the upper and lower guide plates 35d, 35d.
  • This passage 23 for feeding roll-like transfer paper b joins a passage 23' for feeding sheet-like transfer paper b" in the position of transporting rollers 31, 31' disposed upstream of the transfer zone 8, and transfer paper is then forwarded through the common transfer paper-transporting passage 23, extending in a straight line.
  • the passage for transporting a sheet-like transfer paper is thus disposed in a straight line in the machine housing and is circumscribed with the photosensitive drum 6 in the transfer zone 8, even if a very thin or soft paper, cloth, film or foil is used as the sheet-like transfer paper b, paper jamming can be greatly reduced and the copying operation can be accomplished very assuredly.
  • the roll-like transfer paper-cutting mechanism 32 and guide plates 35a, 35a, 35b, 35b positioned between the roll-feeding rollers 30, 30 and transporting rollers 31, 31, and guide plates 35f, 35] positioned between the transporting rollers 54, 54 and transporting rollers 31, 31 are integrally attached to a supporting frame 55 mounted detachably on the frame of the machine housing 1.
  • a supporting frame 55 mounted detachably on the frame of the machine housing 1.
  • guide plates 35e, 35e positioned beteween the sheet-like transfer paper-transporting rollers 53, 53' and the transporting rollers 54, 54' are integrally attached to a supporting frame 56 mounted dismountably on the frame of the machine housing 1, so that these plates can be dismounted from the machine housing together with the supporting frame 56.
  • a transfer mechanism 36 is disposed to bring transfer paper b into contact with the photosensitive layer 5 of the photosensitive drum 6 and thereby transfer the image onto the transfer paper.
  • This transfer mechanism 36 is constructed of a transfer roller alone or in combination with a corona discharge mechanism.
  • the image to be transferred is an electrostatic image
  • it may be transferred onto transfer paper merely by contacting it with the electrostatic image-carrying photosensitive drum by means of a roller.
  • the transfer of the electrostatic image can be accomplished effectively by forming an electric field between the transfer roller and the substrate of the photosensitive drum or by effecting the corona discharge from the back face of transfer paper.
  • the image to be transferred is a toner image
  • it may be transferred onto transfer paper by contacting it with the toner image-carrying photosensitive drum by means of the transfer roller or by static force and forming an electric field between the transfer roller and the substrate of the photosensitive drum or effecting the corona discharge from the back face of the transfer paper.
  • the transfer papentransporting passage indicated as a whole by reference numeral 23 extends downstream of the transfer zone 8.
  • a peeling mechanism 37 which removes transfer paper b from the photosensitive layer 5 of the photosensitive drum 6 and directs it toward the said transporting passage.
  • This peeling mechanism 37 is provided with a peeling projection 38 disposed so that its leading edge brought into contact with the photosensitive layer of said photosensitive drum. Said peeling projection 38 peels off the leading edge of the transfer paper b from the photosensitive layer surface and guides the transfer paper b to the transfer papertransporting passage.
  • a fan 40 provided with a projection nozzle 39 directed toward the peeling projection 38 is disposed to assist peeling of the transfer paper b from the photosensitive layer surface and introduction of transfer paper b into the transfer paper-transporting passage and to accomplish these operations stably and assuredly.
  • a cleaning mechanism 41 to clean the photosensitive layer of the photosensitive drum 6 by removing the toner from the surface thereof.
  • This cleaning mechanism 41 comprises a roller 42 provided with a rubber or brush surface which is rotated while in contact with the photosensitive layer of the drum 6. In the case of electro-static image transfer, of course, this cleaning mechanism may be omitted.
  • the transfer paper-transporting passage 23 extending to the downstream of the transfer zone 8 is provided with pair of driven rollers or one or more endless belts and it transports transfer paper through a subsequent treating zone.
  • the treating zone may be an imagefixing zone, when a toner image is transferred and may include development and fixing zones when a static image is transferred.
  • an endless belt 45 supported and driven by a driving pulley 43 and driven pulleys 44, 44 is mounted to define the lower side of the transfer paper-transporting passage 23 on the upper side of the transfer papertransporting passage 23, a fixation mechanism 46 is disposed to fix the toner image on transfer paper b.
  • This fixation mechanism 46 includes an infrared lamp or electric heater 47 and the fixation of the toner image is accomplished by meltbonding it to transfer paper with heat from the heater.
  • another guiding belt 49 may be mounted on the upper side of the transfer paper-transporting passage 23.
  • the guiding belt 49 is driven and supported by a driving pulley 48 and driven pulleys 48', 48", 48". It is also possible to position pulleys 44' and 48' supporting belts 45 and 49 near the discharge end 203 of the passage 23 in a manner such that the pulleys 44 and 48' contact each other through the belts, whereby transfer paper on which the image has been formed can be discharged assuredly from the fixing zone.
  • a suction mechanism 50 may be provided to suck transfer paper through the endless belt 45, whereby transfer paper will adhere closely and fixedly to the endless belt 45.
  • the guiding belt 49 may be omitted.
  • a known combination (not shown) of an iron roller and a pressing roller may be used as the fixation mechanism 46 without disadvantages.
  • the photosensitive drum 6 be located so that the uppermost part of its circumferential surface is in proximity to, and faces, the upper surface plate 201 of the machine frame 1. This is because by opening the upper surface plate 201, the inspection, repair, etc., of the photosensitive drum 6 can be very easily performed.
  • the transfer paper transporting passage 23 can be oriented substantially horizontally in the lengthwise direction of the machine or it may be oriented in a plane inclined with respect to the lengthwise direction of the machine. However, as is shown in FIG. 1, it is preferred that the transfer section 8 be located in a position which is at an angle exceeding 180C. in the direction of rotation of the photosensitive drum from the uppermost part of the photosensitive drum. Furthermore the transfer paper transporting passage 23 form an upwardly inclined plane ranging from the positions of transfer roller 33, 33 upstream of the transfer zone 8 to the discharge end 201 through the transfer zone 8.
  • the optical system and various paper feed mechanisms are provided above the feed side of the transfer zone 8, only when the transfer paper-transporting passage is provided in the upwardly inclined state, it is possible to secure a space sufficient to house these mechanisms therein.
  • either the height or the length of the machine can be greatly shortened as compared with conventional copying machines of this type.
  • the transfer paper-transporting passage 23 is provided in the state upwardly inclined with respect to the direction of advance of transfer paper, a space sufficient for opening the endless belt 45 downwardly can be provided below the fixing zone and hence, removal of jammed paper can be accomplished with ease.
  • the optical system of the copying machine comprises a light source 18 for light exposure, an opening 17 for exposing the original to light, two reflex mirrors 20 and 21, a mirror lens 22 and an opening 19 for exposing the photosensitive layer 5 to light, these members being disposed on partition walls 61, 62 and 63 or disposed so as to constitute at least part of these partition walls.
  • the opening 17 for exposing the original to light is disposed in the upper portion of the machine housing 1 so that when a moving frame 3 is positioned at a point of initiation of light exposure, it can be optically connected to the standard end point of initiation of light exposure (position P6 detailed hereinafter) which is formed on a transparent plate 2 mounted on the moving frame 3.
  • This opening 17 may be shielded by a transparent plate or it may not be shielded by a transparent plate.
  • the light source 18 for light exposure is disposed on one 61 of partition walls 61, 62 inserting the opening 17 therebetween, in the vicinity of said opening for exposing the original to light. Alternatively, the light source 18 may be disposed on both the partition walls 61 and 62.
  • the opening 19 for exposing the photosensitive layer to light is disposed in the partition wall 62 positioned on the side of the photosensitive drum, and the first reflex mirror 20 is mounted on the partition wall 63 of the optical system while the second reflex mirror 21 and mirror lens 22 are disposed on the partition wall 61 positioned on the opposite side.
  • the first reflex mirror 20 connects the opening 17 for exposure of the original optically with the in-mirror lens 22 and simultaneously connects the mirror lens 22 optically with the second reflex mirror 21.
  • This second reflex mirror 21 is disposed in such a position that it connects the first reflex mirror 20 optically with the opening 19 for exposing the photosensitive layer to light.
  • the optical axis x of the mirror lens 22 be inclined from the horizontal plane by a small angle (generally to 20) in the clockwise direction, and the first and second reflex mirrors 20 and 21 be deviated by an angle of 0 (generally +5 to +20) and 0 (generally 0 to in a clockwise direction from the position at an angle of 45 to the horizontal plane in a counterclockwise direction.
  • the optical system 16 of this embodiment light projected from the light source 18 and reflected from an original a to be copied is reflected by the first reflex mirror 20 and propagated to the mirror lens 22. The light is then reflected from the surface of the mirror lens 22, and is reflected again on the first and second reflex mirrors 20 and 21 and propagated to the photosensitive surface 5 through the opening 19 for exposing the photosensitive layer to light. Thus an image of the original is formed on the photosensitive surface 5.
  • this optical system by arranging the first and second reflex mirrors and the in-mirror lens in an optical chamber so that a specific positional relationship as mentioned above can be attained among these optical members, it is made possible to utilize the first-reflex mirror in a duplicate manner for reflection and propagation of the light.
  • a 4-fold optical passage for the reverse image can be formed by a minimum unit combination of two reflex mirrors and one mirror lens, and since the optical passage is of such 4-fold structure, the space for the optical system can be greatly reduced. Further, since the number of members constituting the optical system is very small, the angle determination in these members can be accomplished very easily.
  • the mirror lens 22 is mounted adjustably on the partition wall 61 to permit easy adjustment of the focal point of the optical system.
  • the focal point can be adjusted as desired by adjusting the mirror lens 22 even when the height of the transparent plate 2 for supporting an original to be copied or the position of the photosensitive layer on the surface of the photosensitive drum is varied.
  • the optical system 16 forms one chamber 64 substantially isolated from a static image-forming zone 7 and a developing zone 7 which are disposed along the passage for movement of the photosensitive layer 5. More specifically, each member of the optical system 16 is disposed inside the partition walls 61, 62, 63 or mounted on such partition wall so that it will act as a part of the partition wall.
  • the opening 19 for light-exposing the photosensitive layer is covered with a transparent plate 65 such as a transparent glass plate and is supported on partition side walls 62, 63 through a sealing packing 66. Accordingly, in the area of the opening 19 of the optical system 16, an optical connection is attained to the area of the photosensitive layer 5 to be exposed while the air current is interrupted.
  • air may be positively passed into the electrostatic image-forming zone 7' by providing an exhaust port of an exhaust gas duct 67 of a fan 40' on a side wall 1 of the machine housing confronting the electrostatic image-forming zone 7.
  • the developing zone is generally disposed just below the zone for forming an electrostatic image by electrification and light exposure. Therefore, operational troubles are brought about by scattering of the toner powder caused with rotation of the developing drum.
  • the side wall of the developing chamber is closely contacted with the photosensitive layer, the electrostatic image formed on the surface of the photosensitive layer is disturbed by friction. In order to prevent occurrence of this undesired phenomenon, a certain clearance should be formed between the side wall of the developing chamber and the surface of the photosensitive layer.
  • the optical system 16 including lens, mirrors and the like is so constructed as to form one chamber and the area of the opening 19 for exposing the photosensitive layer to light is kept in the air-tight state by the transparent plate 65. Therefore, intrusion of the toner powder into the optical system can be effectively prevented. Furthermore since air is positively blown into the static image-forming zone 7' including the electrification and light exposure mechanisms and the pressure can be maintained in this zone 7' at a level higher than in the developing zone 7", scattering and intrusion of the toner powder into the electrostatic image-forming zone can be prevented effectively.
  • the need to frequency clean the electro-static image-forming zone can be greatly reduced and clear copy sheets can be obtained stably even if the copying machine is operated for a long period of time.
  • the developing device used in the copying apparatus of this invention has such a structure as illustrated in FIGS. 3 to 7.
  • the developing device shown generally at 13 includes a developing vessel 68 containing a developer, a stirring member 69 for stirring the developer, and a magnetic brush member 70 provided within the developer vessel 68.
  • the developer may be composed of a toner powder and a magnetic carrier, or of a toner having magnetic properties.
  • the toner powder is rubbed and electrically charged as a result of being stirred by the stirring member 69.
  • this magnetic brush member 70 includes a development sleeve 71 which is hollow and composed of a non-magnetic substance and a magnet means 72 disposed in the stationary state in said development sleeve 71.
  • the magnet means 72 comprises a plurality of magnets 73 and 74 and a magnetism-intercepting member 75, which are provided to satisfy the following positional and arrangement requirements.
  • the magnet forms a magnetic field sufficient to attract a developer to the sleeve surface and to retain the developer there in a zone ranging in therotating direction of the sleeve from the position P of pumping up the developer to the developing position P and the magnetism-intercepting member is disposed so that it weakens the magnetic field in at least a part of a zone ranging in the rotating direction of the sleeve from the developing position P,,, to the position P of pumping up the developer.
  • the magnetic field formed by the magnet has a flux (f, for example, about 1000 gauss) suitable for taking up the developer C at the pumping position P under the sleeve 71, a flux (f about 700 gauss) substantially normal to the circumferential surface of the sleeve at the developing position P and a concentrated flux 02,) along the circumferential surface of the sleeve ranging from the developer-pumping position P to the developing position
  • a first magnet i.e., a magnet brush-forming magnet 73
  • the magnetic brush-forming magnet 73 is composed of a plurality of rectangular magnet pieces bonded to one another, but of course, the magnet 73 may be composed of a single magnet piece.
  • a secondary magnet i.e., a developer-pumping magnet 74
  • pole S or N
  • this developer-pumping magnet 74 may be formed integrally with the brush-forming magnet 73. It is preferred that these magnet brush-forming magnet 73 and developer-pumping magnet 74 are so arranged that their exciting directions are substantially perpendicular to each other.
  • the magnetism-shielding member 75 composed of a non-magnetized magnetic material (for example, nonmagnetic iron) is provided, as shown, so that it weakens a magnetic field formed between the other pole S (or N) of the magnetic brush-forming magnet 73 and the developer-pumping magnet 74 in the rotating direction of the sleeve.
  • a non-magnetized magnetic material for example, nonmagnetic iron
  • the magnetic flux density can be heightened especially at the developing zone Pd to which the end 76 of the pole N of the magnetic brush-forming brush 73 is directed and at the developer-pumping position P, to which the pole S of the developer-pumping magnet 74 is directed.
  • a magnetic flux substantially vertical to the circumference of the sleeve is formed, and moreover, a flux of a relatively high density, i.e., a concentrated flux, is formed between the pole N of the magnet 73 and the pole S of the magnet 74, namely between the developer-pumping position P, and the developing position P along the circumference of the sleeve.
  • the magnetic flux passes the interior of the magnetism-shielding member 75 between the pole S of the magnetic 73 and the magnet 74, namely between the carrier-peeling position Pf located on the opposite side of the developing position Pd and the developer-pumping position P Hence, the magnetic flux density is extremely low on the circumference of the sleeve in such area.
  • the magnet mechanism 72 In conducting the developing operation, the magnet mechanism 72 is arranged fixedly in the state shown in FIG. 4, and when the sleeve 71 is rotated in the counterclockwise direction, the developer c is applied to the peripheral face of the sleeve at the developer-pumping position, whereby pumping of the developer is accomplished.
  • the developer c is transported to the developing zone Pd while being carried on the circumference of the sleeve.
  • a magnetic brush of a high density uniformly extending vertically from the peripheral face of the sleeve is formed, and a close contact of this magnetic brush with the electrostatic image carried on the photosensitive layer 5 can be ensured.
  • the electro-static image on the photosensitive layer is developed with the charge toner retained by the magnetic carrier.
  • the developer which has completed the developing operation is rotated in the counterclockwise direction from the developing position Pd while being carried on the circumference of the sleeve and is transported to the carrier-peeling position Pf located on the opposite side of the developing position Pd.
  • the carrier-peeling position Pf the the magnetic flux density on the peripheral face of the sleeve is drastically lowered and the developer 0' transported while being retained on the circumferential face of the sleeve is peeled off therefrom by the gravity and centrifugal force and is allowed to fall down on the bottom of a developer vessel 68.
  • a stirring mechanism 69 which rotates in the direction opposite to the direction of rotation of the sleeve, namely in the clockwise direction.
  • This stirring mechanism 69 is mounted to stir the developer c having a lowered concentration of the toner powder with a freshly supplied toner powder and to feed a fresh supply of the developer to the developer-pumping position after adjustment of the toner concentration.
  • the surface of the developing sleeve 71 may be smooth or, in order to retain the developer thereon assuredly and easily, the surface can have a roulette, for example, a roulette with a parallel pattern.
  • the magnetism-shielding member 75 or a combination of the magnetism-shielding member 75 with a member 78 composed of non-magnetic substance (for example, aluminum) may be disposed as the magnet-supporting member on the side wall of the developer vessel so that the angle of the magnet mechanism can be adjusted.
  • the magnetic carrierpeeling position Pf can be made closer to the developing position Pd, if, as illustrated in FIG. 4, the magnetism-shielding member 75 is disposed to cover the opposite side pole S of the magnetic brush-forming magnet 73 and the side portion of the pole S positioned on the side where the developer-pumping magnet 74 is provided, and if at the same time as illustrated in FIG. 5, the magnetism-shielding member 75 is disposed to cover the side portion of the pole S positioned on the side opposite to the side where the developer-pumping magnet 74 is provided.
  • a brush length-adjusting mechanism 79 is disposed in the vicinity of the magnetic brush-supporting surface of the magnetic brush mechanism 70, i.e., the surface of the developing sleeve 71, between the developerpumping position P, of the magnetic brush mechanism and the developing position Pd where the magnetic brush is brought into contact with the electro-static image-carrying surface 5.
  • This brush length-adjusting mechanism 79 comprises a sharp edged blade 80 and a slide member 82 mounted movably along the bottom face of the developer vessel 68 on a supporting seat 81 provided on the bottom face of the vessel 68.
  • This slide member 82 includes slots 83 extending in a direction normal to the axis of the magnetic brush mechanism 70. Screws 84 are fitted to the supporting seat 81 through said slots 83, allowing the brush lengthadjusting mechanism 79 to be adjusted. In addition to these adjustment members, any other known mechanisms can be optionally used to adjust the position of the blade edge 80 of the brush length-adjusting mechanism.
  • the distance a between the blade edge 80 of the brush length-adjusting mechanism 79 and the magnetic brush-supporting surface (the surface of the sleeve 71) is made shorter than the distance d between the magnetic brush-supporting surface and the bottom face of the developer vessel at the develeper-pumping position P,,.
  • the distance d between the electro-static imagecarrying surface 5 and the magnetic brushsupporting surface at the developing position P, is made a little shorter than the distance d between the blade edge 80 of the brush length-adjusting mechanism and the magnetic brush-supporting surface.
  • the distance d;, between the electro-static imagecarrying surface 5 and the magnetic brush-supporting surface is varied considerably depending on the kind of the electro-static image-carrying surface. For instance, a good image is obtained when in the case of a zinc oxide photosensitive layer the distance d;, is about 4 mm and in the case of a cadmium sulfide photosensitive layer the distance d is about 2 mm.
  • the distance d; can be easily adjusted as desired, for example, by mounting the entire developing device or the magnetic brush member movably with respect to the sensitive drum.
  • the distance d between the magnetic brush-supporting surface and the bottom face of the developer vessel is made longer than the distance d so that at the developer-pumping position Pp the pumping of the developer can be readily accomplished and a fresh developer can be sufficiently supplied at said pumping position P
  • the distance d, between the blade edge 80 of the brush length-adjusting mechanism and the magnetic brushsupporting surface is made a little longer than said distance d More specifically, the distance d is so set that the value of (d, d is generally 0 to 2 mm, especially about 0.5 mm.
  • a magnetic toner provides magnetic brush of uniform density and a uniform length at the developing zone Pd.
  • An appropriate amount of a developing toner is always stably and uniformly transported to the developing zone Pd. (The amount of the developing toner transported is not so excessive as will cause excessive application of the toner on the electrostatic imagesupporting face and is not so scarce as will cause insufficient application of the toner on the electro-static image-supporting surface.
  • a substantially parallel magnetic brush is formed at the above-mentioned developing zone Pd.
  • the toner powder can be tightly and uniformly contacted with the electro-static image-carrying surface 5 according to the magnetic brush.
  • a developing counter pole 84 may be disposed in the substantially stationary state in the vicinity of the inner face of the portion of the photosensitive drum 6 confronting the magnetic brush mechanism 70.
  • the developing counter pole 84 In order to dispose the developing counter pole 84 in the substantially stationary state in the vicinity of the inner face of the photosensitive drum 6, the developing counter pole 84 is attached to one end of an arm 85, both ends of which are directed downwardly, and a balancing weight 86 is attached to the other end of this arm 85.
  • the central portion of the arm 85 is engaged with or fitted to the rotary shaft 87 of the photosensitive drum 6, so that the arm is freely hanging down from the shaft 87.
  • the developing counter pole 84 When the photosensitive drum is supported in the open side manner on one frame of the machine housing, the developing counter pole 84 is fixed to the other frame of the machine housing. This enables the developing counter pole 84 to always confront the magnetic brush mechanism at the developing position.
  • the developing counter pole 84 When the developing counter pole 84 is disposed in the vicinity of the inner face of the photosensitive drum in the foregoing manner to confront the magnetic brush mechanism at the developing position, the caring of the magnetic brush can be always kept parallel in the vertical direction and maintained in good conditions, and at the same time, the effective area can be enlarged at the developing zone Pd.
  • the substrate of the photosensitive drum may be composed of a magnetic substance, but since the magnetic flux extends in a broad region, the magnetic carrier is adsorbed on the surface of the photosensitive drum 6 and it is transported to the transfer zone and other treatment zones in the state absorbed on the drum surface, which results frequently in bad influences on the image. It is also possible to wind a thin magnetic substance on the inner face of the photosensitive drum, but when this is done, the magnetic resistance is too great and the intended effects cannot be obtained. In the foregoing embodiment of this invention, by disposing the developing counter pole 84 to meet the abovementioned positional requirements, it is possible to reduce the magnetic resistance and to attain the desired effects.
  • an inlet 90 (see FIG. 6) is provided to insert a cylindrical cartridge 89 for supply of a toner into the side wall 88 of the developer vessel, and a supporting member 91 is provided on a toner supply chamber 93 to support rotatably the cartridge 89 inserted from the inlet 90.
  • This toner supply chamber 93 is separated through partition walls 94 and an opening 92 is provided on the lower partition wall.
  • the toner supply cartridge 89 comprises, for instance, as illustrated in FIG. 7, a cylinder 97, both ends 95, 95' of which are closed and which is provided with an opening 96 scalable and openable along the substantially entire length of the cylinder.
  • a toner power is contained in the cylinder.
  • the opening 96 of the cylinder 97 includes outlets of such configuration and dimension that when the sealing of the opening is released and the opening faces downwardly, the toner powder 0 contained in the cylinder is discharged uniformly along substantially the entire length of the cylinder.
  • At least part of at least one of the side walls 95, 95 of the cylinder is made of a transparent or semi-transparent material so that the toner contained in the cylinder can be observed from the outside.
  • a mark 98 is provided indicating the position of the opening 96.
  • the mark may be an arrow, letter, figure, projection or convexity.
  • the opening 96 of the cartridge 89 may be sealed by adhesive tape 99 or the like, or outside edges of the opening 96 may be integrally formed with the cylinder through a cuttable perforated line or the like.
  • the opening 96 of the cartridge 89 In supplying a toner into the toner supply chamber 93, the opening 96 of the cartridge 89 initially faces upwardly, and in this orientation the opening 96 is unsealed. Then, while maintaining the cartridge in this state, it is inserted into the interior of the toner supply chamber 93 through the inlet 90 provided on the side wall 88 of the developer vessel. The cartridge 89 is then rotated 180, whereby the opening 96 of the cartridge faces downwardly and a necessary amount of the toner is supplied into the toner supply chamber 93.
  • the supply of the toner into the developing apparatus 13 can be accomplished very easily without contaminating hands of a machine operator or scattering fine toner powder.
  • provision of the mark 98 indicating the position of the opening 96 on the side edge portion 95 or 95' of the cylinder makes it possible to conduct unsealing of the opening 96 easily without mistake, and insertion of the cartridge into the toner supply chamber 93 and supply of the toner by turning the cartridge to the prescribed position can be performed very easily with certainty.
  • the side edge portion or 95 of the toner supply cartridge 89 is composed of a transparent or semitransparent material, the amount of the toner contained in the cartridge can be easily confirmed from the outside and hence, the supply of the toner can be accomplished promptly without delay.
  • the cylinder of the toner supply cartridge and the inlet 90 have a circular form, but when the inlet 90 is constructed of an individual member rotatable on the side wall of the developer vessel, they may take any other optional form.
  • a packing member 100 of planted hairs or sponge be provided along the periphery of the inlet 90.
  • a toner supply roller 102 having grooves 101 on the surface thereof.
  • ends of elastic members 103 are fixed.
  • the elastic members 103 are composed of a flexible material such as a Mylar film. The free ends of the elastic members 103 are allowed to make contact with the peripheral surface of the toner supply roller 102.
  • the toner supply roller 102 When the toner supply roller 102 is stopped, the toner supply chamber 93 and a developing chamber 104 are in an enclosed state. When the toner supply roller 102 is rotated in the clockwise direction, the toner contained in spaces of the grooves 101 is fed into the developing room 104.
  • the afore-mentioned agitation mechanism 69 is disposed below the toner supply roller 102, and it frictionally charges the freshly supplied toner while mixing it with the magnetic carrier. The resulting developer composition is then fed to the developer-pumping position of the magnetic brush mechanism 70 by means of the agitation mechanism 69.
  • the transfer mechanism 36 used in this embodiment comprises a transfer roller 107 including a roller base 105 composed of an electrically conductive rubber or other electric conductive material such as a metal and an insulating thin layer 106 which is coated on the roller base 105, and an electric source 109.
  • the transfer roller 107 is disposed to press transfer paper 12 against the surface layer 5 of the photosensitive drum 6, and the electric source 109 is provided to apply a voltage between the electrically

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Paper Feeding For Electrophotography (AREA)
  • Electrophotography Configuration And Component (AREA)
  • Combination Of More Than One Step In Electrophotography (AREA)
  • Control Or Security For Electrophotography (AREA)
  • Handling Of Sheets (AREA)
US399516A 1972-09-24 1973-09-21 Electrostatic photographic copying apparatus Expired - Lifetime US3923391A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US05/570,428 US4040387A (en) 1972-09-24 1975-04-22 Electrostatic photographic copying apparatus
US05/570,426 US4033689A (en) 1972-09-24 1975-04-22 Compact optical system for an electrostatic photographic copying apparatus
US05/570,427 US4012139A (en) 1972-09-24 1975-04-22 Electrostatic copying apparatus having copy paper cut length control

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9546072A JPS552867B2 (de) 1972-09-24 1972-09-24

Related Child Applications (3)

Application Number Title Priority Date Filing Date
US05/570,427 Division US4012139A (en) 1972-09-24 1975-04-22 Electrostatic copying apparatus having copy paper cut length control
US05/570,426 Division US4033689A (en) 1972-09-24 1975-04-22 Compact optical system for an electrostatic photographic copying apparatus
US05/570,428 Division US4040387A (en) 1972-09-24 1975-04-22 Electrostatic photographic copying apparatus

Publications (1)

Publication Number Publication Date
US3923391A true US3923391A (en) 1975-12-02

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ID=14138272

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US399516A Expired - Lifetime US3923391A (en) 1972-09-24 1973-09-21 Electrostatic photographic copying apparatus

Country Status (7)

Country Link
US (1) US3923391A (de)
JP (1) JPS552867B2 (de)
DE (1) DE2348041C3 (de)
FR (1) FR2209134B1 (de)
GB (2) GB1438969A (de)
IT (1) IT993385B (de)
NL (2) NL162220C (de)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4171900A (en) * 1975-03-13 1979-10-23 Brugger Richard D Copying machine
US4312468A (en) * 1980-05-15 1982-01-26 Pitney Bowes Inc. System and apparatus for compensating for the difference between the actuation and release points of a switch
US4325626A (en) * 1978-12-13 1982-04-20 Mita Industrial Co., Ltd. Electrostatic copying apparatus
US4334772A (en) * 1979-02-02 1982-06-15 Olympus Optical Company Limited Electrophotographic apparatus of retentive type
US4420152A (en) * 1979-02-02 1983-12-13 Olympus Optical Company Limited Apparatus for peeling or separating a record paper from a photosensitive drum of an electrophotographic copying machine
US4441636A (en) * 1981-06-23 1984-04-10 Hitachi Metals, Ltd. Toner cartridge
US4615608A (en) * 1983-10-31 1986-10-07 Canon Kabushiki Kaisha Developing apparatus
US5729788A (en) * 1995-03-16 1998-03-17 Fuji Xerox Co., Ltd. Image forming apparatus having control structure for cleaning the transfer device
US5878306A (en) * 1997-07-18 1999-03-02 Michlin; Steven Bruce Disposable strip holder installation device and method used in the imaging and other industries
US6356724B1 (en) * 1995-01-10 2002-03-12 Steven Bruce Michlin Disposable strip holder installation device and placement holding device and method for copiers, laser printers, fax machines and for toner cartridges used therein

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Publication number Priority date Publication date Assignee Title
JPS5326985Y2 (de) * 1972-11-22 1978-07-08
JPS5272233A (en) * 1975-12-12 1977-06-16 Minolta Camera Co Ltd Detector for paper jam in the electrophotographic copying machine
IT1057196B (it) * 1976-02-16 1982-03-10 Olivetti C E C S P A Cartuccia per il rifornimento della polvere di sviluppo in una macchina copiatrice
JPS53142243A (en) * 1977-05-17 1978-12-11 Canon Inc Electrophotographic image former
JPS5463851A (en) * 1977-10-31 1979-05-23 Toshiba Corp Electrochromic display device
DE2903265C3 (de) * 1979-01-29 1981-12-24 Siemens AG, 1000 Berlin und 8000 München Vorrichtung zum Transport eines Bildempfangsmaterials durch eine Bildübertragungsstation und zum An-/bzw. Abschwenken des Bildempfangsmaterials an bzw. von einem Zwischenbildträger in der Bildübertragungsstation eines Kopiergerätes oder nichtmechanischen Aufzeichnungsgerätes
JPS55120065A (en) * 1979-03-09 1980-09-16 Ricoh Co Ltd Electrophotographic copier
DE3132612A1 (de) * 1981-08-14 1983-04-21 Hitachi Metals, Ltd., Tokyo Tonerpatrone

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US3139013A (en) * 1962-01-09 1964-06-30 Xerox Corp Document reproducing apparatus
US3236165A (en) * 1964-01-02 1966-02-22 Xerox Corp Xerographic reproducing apparatus
US3399610A (en) * 1965-10-22 1968-09-03 Xerox Corp Xerographic apparatus
US3635554A (en) * 1969-09-26 1972-01-18 Eastman Kodak Co Exposure system
US3689146A (en) * 1969-05-02 1972-09-05 Canon Kk Electrophotographic copying machine
US3784297A (en) * 1970-03-11 1974-01-08 Canon Kk Photocopying machine

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JPS4218636Y1 (de) * 1965-05-25 1967-10-27

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Publication number Priority date Publication date Assignee Title
US3139013A (en) * 1962-01-09 1964-06-30 Xerox Corp Document reproducing apparatus
US3236165A (en) * 1964-01-02 1966-02-22 Xerox Corp Xerographic reproducing apparatus
US3399610A (en) * 1965-10-22 1968-09-03 Xerox Corp Xerographic apparatus
US3689146A (en) * 1969-05-02 1972-09-05 Canon Kk Electrophotographic copying machine
US3635554A (en) * 1969-09-26 1972-01-18 Eastman Kodak Co Exposure system
US3784297A (en) * 1970-03-11 1974-01-08 Canon Kk Photocopying machine

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4171900A (en) * 1975-03-13 1979-10-23 Brugger Richard D Copying machine
US4325626A (en) * 1978-12-13 1982-04-20 Mita Industrial Co., Ltd. Electrostatic copying apparatus
US4334772A (en) * 1979-02-02 1982-06-15 Olympus Optical Company Limited Electrophotographic apparatus of retentive type
US4420152A (en) * 1979-02-02 1983-12-13 Olympus Optical Company Limited Apparatus for peeling or separating a record paper from a photosensitive drum of an electrophotographic copying machine
US4312468A (en) * 1980-05-15 1982-01-26 Pitney Bowes Inc. System and apparatus for compensating for the difference between the actuation and release points of a switch
US4441636A (en) * 1981-06-23 1984-04-10 Hitachi Metals, Ltd. Toner cartridge
US4615608A (en) * 1983-10-31 1986-10-07 Canon Kabushiki Kaisha Developing apparatus
US6356724B1 (en) * 1995-01-10 2002-03-12 Steven Bruce Michlin Disposable strip holder installation device and placement holding device and method for copiers, laser printers, fax machines and for toner cartridges used therein
US5729788A (en) * 1995-03-16 1998-03-17 Fuji Xerox Co., Ltd. Image forming apparatus having control structure for cleaning the transfer device
US5878306A (en) * 1997-07-18 1999-03-02 Michlin; Steven Bruce Disposable strip holder installation device and method used in the imaging and other industries

Also Published As

Publication number Publication date
NL162220C (nl) 1980-04-15
NL7313118A (de) 1974-03-26
FR2209134B1 (de) 1982-11-19
DE2348041A1 (de) 1974-04-04
NL7905312A (nl) 1979-10-31
JPS4953838A (de) 1974-05-25
JPS552867B2 (de) 1980-01-22
GB1438970A (en) 1976-06-09
IT993385B (it) 1975-09-30
DE2348041C3 (de) 1979-09-20
FR2209134A1 (de) 1974-06-28
GB1438969A (en) 1976-06-09
NL162220B (nl) 1979-11-15
DE2348041B2 (de) 1979-01-18

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