US3472205A - Developing device for an electrostatic recording apparatus - Google Patents

Developing device for an electrostatic recording apparatus Download PDF

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Publication number
US3472205A
US3472205A US559141A US3472205DA US3472205A US 3472205 A US3472205 A US 3472205A US 559141 A US559141 A US 559141A US 3472205D A US3472205D A US 3472205DA US 3472205 A US3472205 A US 3472205A
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US
United States
Prior art keywords
developing
powder
vessel
recording
supplementary
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
US559141A
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English (en)
Inventor
Takeshi Tsuchiya
Tetsuo Takahashi
Kiyoshi Yamamoto
Akito Yanai
Mikio Takiura
Toshio Kano
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.)
Toshiba Corp
Original Assignee
Tokyo Shibaura Electric Co Ltd
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Application filed by Tokyo Shibaura Electric Co Ltd filed Critical Tokyo Shibaura Electric Co Ltd
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J31/00—Cathode ray tubes; Electron beam tubes
    • H01J31/02—Cathode ray tubes; Electron beam tubes having one or more output electrodes which may be impacted selectively by the ray or beam, and onto, from, or over which the ray or beam may be deflected or de-focused
    • H01J31/06—Cathode ray tubes; Electron beam tubes having one or more output electrodes which may be impacted selectively by the ray or beam, and onto, from, or over which the ray or beam may be deflected or de-focused with more than two output electrodes, e.g. for multiple switching or counting
    • H01J31/065—Cathode ray tubes; Electron beam tubes having one or more output electrodes which may be impacted selectively by the ray or beam, and onto, from, or over which the ray or beam may be deflected or de-focused with more than two output electrodes, e.g. for multiple switching or counting for electrography or electrophotography, for transferring a charge pattern through the faceplate

Definitions

  • a developing device for an electrostatic recording apparatus wherein a supplementary developing agent contained within a supplementary vessel is transferred to the main developing vessel by means of a rotating magnetic brush mounted in the supplementary vessel which supplies the supplementary developing agent to a conveying means which is maintained at a voltage having a polarity opposite to that of the charge of the supplementary developing powder to attract the supplementary developing powder.
  • Scraping means is provided for removing the supplementary developing powder from the conveying means, and removed powder falling into the main developing vessel to supplement the developing powder therein.
  • This invention relates to a multi-electrode type electrostatic recording device and more particularly to improvements in the relating to an electrode member for recording electrostatic latent images and developing means for converting electrostatic latent images into visible powder images.
  • the recording electrode member adapted to form electrostatic latent images on a recording medium generally comprises an electric insulator made of synthetic resin, for example, and a plurality of needle electrodes embedded in said insulator along a straight line.
  • a signal voltage distributor is utilized comprising a plurality of stationary annular distributing electrodes of the number corresponding to that of the needle electrodes and rotary electrodes or brushes sliding on respective distributing electrodes.
  • received input signals are impressed upon the rotary electrodes of the signal voltage distributor, and the signal voltage is sequentially applied to respective distributing electrodes through direct coupling or electrostatic coupling between the rotary electrodes and the re spective distributing electrodes as the rotary electrodes rotates, thus impressing the signal voltage for forming an latent image upon each of said needle electrodes.
  • an electrostatic image of the needle electrodes which have been scanned by the rotary electrodes is formed on the recording medium which is moving across the tips of the recording electrodes.
  • the latent image formed on the recording medium is then developed or visualized by a developing process utilizing a magnetic brush method, for example, and thereafter converted into a permanent image by any suitable fixing technique by means of heat fusing process or the like.
  • the density of scanning lines of 4 lines per millimeter is required to obtain images of ordinary resolution, and most of the scanning width is of the order of 250 mm. Accordingly, it is necessary to use as many as 1,000 needle electrodes in the recording electrode member and hence 1,000 lead wires are required to connect these needle electrodes to the signal voltage distributor.
  • the recording device small and light in weight.
  • it. is extremely difficult to manufacture an electrode member for recording having a resolution of more than 4 lines per millimeter from the standpoint of manufacturing engineering.
  • the electrode member of electrostatic recording is very expensive and requires complicated fabrication steps because it comprises a plurality of needle electrodes embedded in an insulator made of synthetic resin.
  • the magnetic brush method is commonly utilized at the means for developing latent images formed by said electrode member for recording to obtain visible powder images.
  • a mixture of a carrier consisting of iron powder and a developing powder consisting of fine powder of a colored resin is utilized as the developing agent which is adapted to be attracted by a magnet to develop the latent image into a visible powder image. Since the developing powder alone is consumed during developing operation it is necessary to constantly supplement it so that the developing agent is always maintained in the best condition. However, since the developing powder comprising resin powder has a strong tendency to coagulate it is diflicult to continuously supplement it to a developing vessel at a small rate, so that, at present it is very diflicult to supplement under the best condition the developing powder to the developing Vessel.
  • Another object of this invention is to provide an improved multi-electrode type electrostatic recording device capable of greatly prolonging the useful life of the signal voltage distributing device and also increase the scanning speed.
  • a further object of this invention is to provide a novel multi-electrode type electrostatic recording device having a recording electrode element and a signal voltage distributing mechanism which are prepared by print wire technique.
  • a still further object of this invention is to provide an improved method of and apparatus for automatically supplementing a developing powder by which a small quantity of the developing powder adapted to develop a latent image into a visible powder image is continuously supplemented to the developing vessel.
  • Yet another object of this invention is to provide a novel method and apparatus for automatically supplementing developing powder by which the ratio of mixing a carrier and the developing powder in the developing agent is always maintained at the best condition.
  • FIG. 1 is a plan view showing a base plate of a signal voltage distributor of an electrostatic recording device embodying this invention
  • FIG. 2 shows a sectional view of one example of a recording electrode member of a multi-electrode type electrostatic recording device constructed according to the principle of this invention:
  • FIG. 3 is a side view, partly in section, of a modified electrode member for recording shown in FIG. 2;
  • FIG. 4 is a diagrammatic view showing the construction of one example of a developing member of an electrostatic recording device according to this invention.
  • FIG. 5 is a diagrammatic view of a modified developing member shown in FIG. 4.
  • FIG. 1 illustrates one example of a base plate of a signal distributor for use in an electrostatic recording device of this invention
  • the base plate 20 of a signal distributor comprises a laminated board 21 consisting of an electric insulator sheet with metal foils, copper foils for example, are bonded to the opposite sides thereof, a plurality of distributing segments 22a, 22b which are mounted on a circle at substantially the central portion of the laminated board 21, and a plurality of recording heads 23a, 23b of the same number as said segments 22a, 22b said recording heads being mounted in parallel along one edge of the laminated board 21.
  • segments 22a, 22b and corresponding recording heads are interconnected by lead wires 24a, 24b.
  • the segments 22a, 22b lead wires 24a, 24b
  • recording heads 23a, 23b are formed by removing all portions of one of the copper foils except those comprising these elements by any suitable method such as the photoetching process, offset-printing process, chemical plating and the like.
  • a reenforcing plate 25 is mounted on the underside of the base plate 20 of the signal distributor and an electric conductive ring 29 is mounted by means of supporting posts 27 and 28 on the reenforcing plate 25 and another reenforcing plate 26 which is disposed on the recording head 23a.
  • a shaft 30 for rotating an distributor arm is provided to extend through and journalled by the center of distributing segments 22a, 22b of the base plate 20 of the signal distributor.
  • the central portion of the distributing arm 31 is secured to the rotary shaft 30 while the opposite ends of the arms 31 are provided with electric conducting brushes 32 and 33, one of the brushes 32 being disposed to slide on the electric conductive ring 29 whereas the other brush 33 to slide on the distributing segments 22a, 22b.
  • the width of the distributing brush 33 as measured in the direction of rotation is made sufliciently smaller than the width of the distributing segments 22a, 22b.
  • the reference numeral 34 represents an electrostatic recording sheet.
  • the electrostatic recording sheet 35 is moved in direct contact with the recording surface of the recording heads 23a, 23b and is also moved in the direction perpendicular to the base plate 20 of the signal distributor as viewed in FIG. 1 and in the direction indicated by an arrow, as shown in FIG. 2. Then, the distributing arm 31 is rotated at a desired number of revolutions. An input picture signal voltage impressed upon the conductive supply ring 29 will thus be sequentially supplied to various distributing segments 22a, 22b through the electric conductive brush 32, through the distributing arm 31 and the electric conductive brush 33. The input picture signal voltage supplied to these seg ments 22a, 22b is then successively supplied to respective recording heads 23a, 23b via lead wires 24a, 24b
  • the signal voltage is distributed on the electrostatic recording sheet from its left end to its right hand end to effect horizontal scanning and hence is recorded on the sheet.
  • the electrostatic image thus recorded is developed or visualized into a visible powder image by means of a developing process to be described later.
  • the electrode member for recording is constructed as above described, the distributing mechanism and the recording heads are fabricated as a unitary structure which contributes to reduce dimensions and weight of the device and to substantially eliminate wiring work. Therefore, the recording device can be fabricated at low cost.
  • the base plate of the signal distributor shown and described in the foregoing embodiment may be semicircular, if desired, and the electric conductive ring may be mounted at a position indicated by dotted lines 36 shown in FIG. 1.
  • FIG. 3 shows a modified electrode member for recording for use in the electrostatic recording device of this invention.
  • a reenforcing plate 45 is secured to the lower surface of the base plate 20 of a signal distributor which is shown in FIG. 1 and a cathode ray tube 46 is secured on the upper surface of the base plate 20.
  • the cathode ray tube 46 is not provided with the usual fluorescent glass plate but the base plate 20 serves as a target, and there is provided a suitable deflecting system (not shown) to scan the distributing segments 22a, 22b with an electron beam emitted from an electron gun, not shown.
  • a reenforcing plate 47 is mounted upon the upper surface of the recording heads 23a, 23b.
  • the reference numeral 48 designates an electrostatic recording sheet.
  • the electrostatic recording sheet is held in direct contact with the recording surface of the recording heads 23a, 23b or is maintained to face to the recording surface with a suitable air gap.
  • the recording sheet is moved in the direction of an arrow to effect vertical scanning.
  • the vertical and horizontal deflectors of the deflecting system are adjusted to cause the electron beam emitted from the electron gun to scan in circular pattern and at a required speed to surfaces of distributor segments on the base plate 20 of the signal distributor.
  • the intensity of the electron beam emitted from the electron gun of the cathode ray tub 46 is modulated by the signal to be recorded an electric charge corresponding to the signal voltage to be recorded will be successively applied to the respective distributor segments 22a, 22b at the desired speed.
  • the signal voltage to be recorded which has been distributed among distributor segments 22a, 22b in this manner will be sequentially supplied to respective recording heads 23a, 23b through lead wires 24a, 24b whereby the voltage is distributed on the electrostatic recording sheet 48 from its left hand end toward its right hand end thus effecting horizontal scanning and the signal voltage is recorded on the sheet.
  • the recorded latent image will be visualized to form a visible powder image by the developing process to be described later.
  • electron beam scanning is substituted for the mechanical contact scanning of the first embodiment with the result that wear and friction are eliminated and the useful life of the device can be prolonged. Moreover, it is also possible to increase th scanning speed.
  • shielding wires are formed between electrodes by a suitable etching process the resolution can be further improved.
  • a developing agent 51 consisting of a mixture of a suitable quantity of a carrier comprising iron powder and a developing powder comprising a colored resin powder is contained in a developing vessel 52.
  • a adjacent to this vessel 52 is disposed a developing powder supple mentary vessel 53 which contains supplementary developing agent 54 consisting of a mixtur of the developing powder and iron powder carrier, said mixture containing the former at a higher percentage than the latter.
  • Both vessels 52 and 53 are opened at their upper portions and a metal roller 55 is positioned above the adjoining edges of these vessels, said roller being rotated such that its lower surface rotates from the vessel 53 to the vessel 52, or in the clockwise direction as viewed in FIG. 1.
  • Magnetic brushes rotating about axes 56 and 57 are mounted respectively in the developing vessel 52 and the developing powder supplementary vessel 53, said magnetic brushes being so constructed and arranged that their poles are intermittently brought close to the metal roller 55.
  • a DC. voltage from a DC. source 61 is applied to the metal roller through a voltage adjuster 60 which is operated in synchronism with the rotation of the magnetic brush 58 in the developing vessel 52 in such a manner that it will interrupt the voltage or decrease the voltage to a very low value when the magnetic pole of the magnetic brush 58 is rotated to a position close to the metal roller 55.
  • the carrier and developing powder are electrostatically charged to opposite polarities by the agitation caused by the rotary magnetic brush 59.
  • the polarties of these'charges are dependent upon the material of the developing powder. For example, it is assumed now that the polarity of the charge of the developing powder is positive and that of the iron powder carrier is negative, then a negative voltage will be impressed upon the metal roller 55 from the DC. source 61 by; manipulating the voltage adjuster 60.
  • the novel developing device is especially suitable for continuously developing a number of electrostatic latent images as in an electrostatic facsimile picture. receiving apparatus, for example.
  • FIG. 5 illustrates a modified embodiment of the developing device comprising a developing agent container or vessel 72 containing a developing agent 71 consisting of a mixture of an iron powder carrier and a suitable amount of developing powder and a developing agent supplementary vessel 73 positioned adjacent to the vessel 72.
  • a developing agent container or vessel 72 containing a developing agent 71 consisting of a mixture of an iron powder carrier and a suitable amount of developing powder
  • a developing agent supplementary vessel 73 positioned adjacent to the vessel 72.
  • the top portions of vessels 72 and 73 are open and the supplementary developing agent 74 contained in the vessel 73 contains higher proportion of developing powder than that of the carrier.
  • a metal roller 75 with its peripheral surface covered by an insulating coating, which is rotated such that that its lower surface moves from the supplementary vessel 73 towards the developing vessel 72.
  • a rotary magnetic brush 76 which serves to stir the supplementing developing agent 74 contained therein and is rotated such that its pole is brought into sliding engagement with the periphery of the metal roller.
  • a scraper 78 for the developing powder which is hinged at one end and biased to engage the peripheral surface of the roller 75 by means of a spring 77.
  • a DO. bias voltage is impressed upon the metal roller from a DC. source 79.
  • the carrier and the developing powder are charged with electrostatic charges of opposite polarities. If it is supposed now that the carrier is charged negatively, while the developing powder positively, the metal roller 75 is to be supplied with negative bias voltage from the DC. source 79.
  • the magnetic brush 76 Upon rotation of the magnetic brush 76, its pole will carry the positively charged developing powder which is being attracted by it to the metal roller 75. Since, in this case, the metal roller 75 is impressed with a negative biasing voltage as above mentioned, the positively charged developing powder will be attracted by and transferred onto the peripheral surface of the rotating metal roll when the pole of the magnetic brush 76 is brought into sliding engagement with the roller 75, and the developing powder is then conveyed towards the developing vessel 72 as the roller rotates. The developing powder is then removed from the roller 75 by the action of the scraper 78 and falls into the developing vessel as a supplementary developing powder.
  • the scraper 78 may be moved vertically by providing a number of slots on the outer periphery of the metal roller 75 in parallel with the axis of the roller. While in the above described embodiments the developing powder was attracted by the metal roller 75 by applying a biasing voltage thereto, the powder can also be attracted by a static charge formed on the roller by friction. Further, the means for conveying the developing powder is not limited to metal roller but a conveyor belt travelling from the developing powder supplemental vessel to the developing vessel can also be utilized.
  • this modification is also suitable for continuously developing a number of latent images.
  • a developing device for an electrostatic recording apparatus comprising:
  • a developing vessel which contains a developing agent consisting of a developing powder and a carrier;
  • a supplementary vessel which contains a supplementary developing agent consisting of the developing powder and the carrier and containing the former at a higher percentage than the latter;
  • a rotatable magnetic brush mounted in said supplementary vessel and for stirring the supplementary developing agent to charge the supplementary developing powder and the carrier to have opposite polarities, said magnetic brush also attracting the supplementary powder and the carrier;
  • conveying means slidably engageable by said brush and located above said developing vessel for conveying said supplementary developing powder from said supplementary vessel to said developing vessel;
  • a voltage source connected to said conveying means and supplying thereto a voltage having a polarity oppositeto that of the charge of the supplementary developing powder, said voltage serving to attract the supplementary developing powder onto said conveying means;
  • scraping means adapted to be brought in contact with said conveying means for removing said supplementary developing powder from said conveying means, said removed powder falling into said developing vessel to supplement said developing powder.
  • the developing device further comprising a voltage adjuster operated in synchronism with the rotation of said scraping magnetic brush such that when the pole of said scraping brush is rotated to a position close to said metal roller, said adjuster causes the voltage supplied to said metal roller to decrease to a low value which is insuflicient for said metal roller to hold the supplementary developing powder.
  • said scraping means comprises:

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  • Developing For Electrophotography (AREA)
  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)
  • Electrophotography Using Other Than Carlson'S Method (AREA)
  • Dry Development In Electrophotography (AREA)
US559141A 1965-06-25 1966-06-21 Developing device for an electrostatic recording apparatus Expired - Lifetime US3472205A (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP5185665 1965-06-25
JP4137465 1965-07-10
JP6081965 1965-07-24
JP6268565 1965-07-31

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US3472205A true US3472205A (en) 1969-10-14

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US559141A Expired - Lifetime US3472205A (en) 1965-06-25 1966-06-21 Developing device for an electrostatic recording apparatus

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US (1) US3472205A (enrdf_load_stackoverflow)
DE (1) DE1487692B2 (enrdf_load_stackoverflow)
GB (1) GB1134710A (enrdf_load_stackoverflow)
NL (1) NL6608923A (enrdf_load_stackoverflow)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3575139A (en) * 1969-06-04 1971-04-20 Xerox Corp Electrostatic magnetic developer unit gating apparatus
US3608522A (en) * 1969-06-04 1971-09-28 Xerox Corp Xerographic development control apparatus
US3640248A (en) * 1969-06-04 1972-02-08 Xerox Corp Electrostatic magnetic developing apparatus
US3654902A (en) * 1969-11-28 1972-04-11 Plastic Coating Corp Toner unit for photoelectrostatic reproduction
US3850662A (en) * 1971-09-10 1974-11-26 Kalle Ag Electrophotographic developing process and apparatus
US4391503A (en) * 1980-04-02 1983-07-05 Gestetner Manufacturing Limited Magnetic brush developer unit for photocopier

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IL65819A (en) * 1982-05-19 1984-11-30 Gur Optics & Systems Ltd Image transmission devices

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2967082A (en) * 1955-05-20 1961-01-03 Burroughs Corp Electrographic plotter
US3133834A (en) * 1961-06-22 1964-05-19 Rca Corp Electrostatic developing apparatus
US3140199A (en) * 1961-04-28 1964-07-07 Eastman Kodak Co Vibrating belt powder cloud generator for xerography
US3152012A (en) * 1960-12-19 1964-10-06 Ibm Apparatus for the development of electrostatic images
US3160091A (en) * 1959-05-14 1964-12-08 Xerox Corp High speed xeroprinter and method therefor
US3213309A (en) * 1961-08-14 1965-10-19 Burroughs Corp Electrostatic printing tube
US3283069A (en) * 1960-04-22 1966-11-01 Jack E Macgriff Electron emission control tube and method
US3308473A (en) * 1963-03-21 1967-03-07 Tokyo Shibaura Electric Co Picture signal receiving system
US3367307A (en) * 1965-06-02 1968-02-06 Arlside Ltd Electrostatographic developing apparatus

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2967082A (en) * 1955-05-20 1961-01-03 Burroughs Corp Electrographic plotter
US3160091A (en) * 1959-05-14 1964-12-08 Xerox Corp High speed xeroprinter and method therefor
US3283069A (en) * 1960-04-22 1966-11-01 Jack E Macgriff Electron emission control tube and method
US3152012A (en) * 1960-12-19 1964-10-06 Ibm Apparatus for the development of electrostatic images
US3140199A (en) * 1961-04-28 1964-07-07 Eastman Kodak Co Vibrating belt powder cloud generator for xerography
US3133834A (en) * 1961-06-22 1964-05-19 Rca Corp Electrostatic developing apparatus
US3213309A (en) * 1961-08-14 1965-10-19 Burroughs Corp Electrostatic printing tube
US3308473A (en) * 1963-03-21 1967-03-07 Tokyo Shibaura Electric Co Picture signal receiving system
US3367307A (en) * 1965-06-02 1968-02-06 Arlside Ltd Electrostatographic developing apparatus

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3575139A (en) * 1969-06-04 1971-04-20 Xerox Corp Electrostatic magnetic developer unit gating apparatus
US3608522A (en) * 1969-06-04 1971-09-28 Xerox Corp Xerographic development control apparatus
US3640248A (en) * 1969-06-04 1972-02-08 Xerox Corp Electrostatic magnetic developing apparatus
US3654902A (en) * 1969-11-28 1972-04-11 Plastic Coating Corp Toner unit for photoelectrostatic reproduction
US3850662A (en) * 1971-09-10 1974-11-26 Kalle Ag Electrophotographic developing process and apparatus
US4391503A (en) * 1980-04-02 1983-07-05 Gestetner Manufacturing Limited Magnetic brush developer unit for photocopier

Also Published As

Publication number Publication date
DE1487692B2 (de) 1971-04-29
GB1134710A (en) 1968-11-27
NL6608923A (enrdf_load_stackoverflow) 1966-12-27
DE1487692A1 (de) 1969-04-30

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