US3698926A - Method and apparatus for supplementing toner in electrophotographic machines - Google Patents

Method and apparatus for supplementing toner in electrophotographic machines Download PDF

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Publication number
US3698926A
US3698926A US88378A US3698926DA US3698926A US 3698926 A US3698926 A US 3698926A US 88378 A US88378 A US 88378A US 3698926D A US3698926D A US 3698926DA US 3698926 A US3698926 A US 3698926A
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United States
Prior art keywords
toner
developing agent
developing
percentage
supplementing
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Expired - Lifetime
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US88378A
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English (en)
Inventor
Masayoshi Furuichi
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Katsuragawa Electric Co Ltd
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Katsuragawa Electric Co Ltd
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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
    • G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
    • G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
    • G03G15/0822—Arrangements for preparing, mixing, supplying or dispensing developer
    • G03G15/0848—Arrangements for testing or measuring developer properties or quality, e.g. charge, size, flowability
    • G03G15/0849—Detection or control means for the developer concentration
    • G03G15/0853—Detection or control means for the developer concentration the concentration being measured by magnetic means

Definitions

  • Electrostatic latent images formed on a photosensitive element of an electrophotographic machine are generally developed by applying a powdery developing agent consisting of a magnetic carrier and a non-magnetic toner.
  • the toner adheres to the latent image whereas the carrier does not so that after repeated use of the developing agent the percentage content of the toner gradually decreases. For this reason, it is necessary to supplement the toner from time to time so as to maintain its percentage content in the developing agent at a predetermined constant level.
  • Another object of this invention is to provide a novel electrophotographic machine utilizing a developing agent always containing a toner at a constant percentage, thus producing copies of constant quality.
  • the impedance variation can be detected by any conventional device such as a bridge circuit and is utilized to supplement the toner.
  • FIG. 1 shows a block diagram to explain the principle of this invention.
  • FIG. 1 there is shown a block diagram showing the electric connection of essential elements of the toner supplementing device embodying the invention.
  • the toner supplementing device comprises a detector 1 to detect the variation in the percentages of the toner contained in the developing agent for use in electrophotography to produce an electric signal, a source of reference voltage 2, and a balanced type comparator 3 for comparing the outputs from detector 1 and source 2 to produce an output voltage when the percentage of the toner decreases below a predetermined level.
  • the output from the comparator 3 is supplied to an electromagnetic switch 6 for an electric motor 5 through an amplifier 4 for operating a toner supply mechanism 7 whenever the percentage of the toner decreases below the predetermined level.
  • the developing apparatus 8 comprises a casing 19 disposed to cover at least one side of the rotatary drum 12, a bucket conveyor 20 disposed in the casing to convey the powdery developing agent in the bottom thereof and to sprinkle the developing agent onto the external surface of the photosensitive element on which the latent image has been formed as above described.
  • a rotary magnetic brush 21 is provided close to the periphery of the rotary drum 12 to collect surplus developing agent which has not adhered to the latent image.
  • a funnel of non-magnetic material 22 is disposed below magnet brush 21 to receive the powdery developing agent collected thereby.
  • An inductance coil 23 is wound about the neck of the funnel. The reactance of the inductance coil is varied in accordance with the percentage of the toner contained in the developing agent.
  • Inductance coil 23 is connected across the secondary winding 25 of a power transformer 24 in series with a full wave rectifier 26.
  • a smoothing capacitor 27 and a resistor 28 are connected in parallel across the output terminals of the rectifier.
  • inductance coil 23 and rectifier 26 constitute detector 1 and produce a voltage across resistor 28 which varies with the impedance variation of the inductance coil.
  • a full wave rectifier 30* is connected across another secondary winding 29 of the power transformer and a smoothing capacitor 31, a resistor 32, a Zener diode 33 and a variable resistor 34- are connected in parallel across the output terminals of rectifier 30 thus producing a constant reference voltage across the variable resistor 34.
  • the comparator 3 comprises a bridge circuit including the resistor 28 in the detector 1, variable resistor 34 in the reference voltage generator 2 and two resistors 35 and 36.
  • the output voltage from the bridge circuit is amplified by the amplifier 4 comprising a full wave rectifier 38 energized by a third secondary winding 37 of the power transformer 24, a resistor 39 and a smoothing capacitor 40 which are connected in parallel with the output terminals of rectifier 38, and a transistor 41.
  • the emitter electrode of transistor 41 is connected to one output terminal of rectifier 38 through a resistor 42 whereas the collector electrode is connected to the other output electrode.
  • the base and emitter electrodes of transistor 41 are connected across the output terminals of comparator 3.
  • the emitter electrode of transistor 41 is also connected to the operating coil 44 of the electromagnetic switch 6 through a. transistor 43 to control motor 5.
  • the sieve type toner supply mechanism illustrated can be replaced by any other type supply mechanism, such as a screw conveyor, for example.
  • the invention provides a novel apparatus for automatically supplementing the toner to the developing apparatus of electrophotographic apparatus, whereby to maintain at a constant value the percentage of the toner contained in the developing-agent.
  • apparatus for maintaining a constant percentage of toner in a developing agent utilized for developing latent electrostatic images formed on a photosensitive element, said developing agent comprising a mixture of toner and a magnetic carrier
  • said apparatus comprising a source of said toner, a container for said developing agent, means for detecting the percentage of said toner in said developing agent and means responsive to said detecting means for supplying said toner to said container, the improvement comprising means for detecting the relative amount of magnetic carrier in said developing agent to indirectly determine the relative amount of toner therein, said detecting means including a funnel of nonmagnetic material disposed to receive developing agent as it falls from said photosensitive element, an inductance coil surrounding said funnel and having its inductance varied in accordance with the percentage of magnetic carrier in the developing agent, and means responsive to said inductance variation for producing an electric signal for controlling said toner supply means.
  • a method for maintaining a constant percentage of toner in a developing agent utilized for developing latent electrostatic images formed on a photosensitive element of an electrophotographic machine said developing agent comprising a mixture of toner and a magnetic carrier
  • said method comprising the steps of storing a supply of said toner, storing said developing agent, detecting the percentage of toner in said developing agent and supplying toner to said developing agent in response to a decreased percentage of toner in the developing agent so as to maintain the percentage of said toner at a constant level
  • the improvement which comprises utilizing said magnetic carrier to indirectly determine and to control the amount of toner in said developing agent including the steps of providing a path for developing agent falling from aid photosensitive element, providing a magnetic-responsive element surrounding said path, transmitting an electrical signal through said element, whereby variations in said signal are produced in accordance with the relative content of magnetic material in said path, and utilizing said signal variations for controlling the supply of toner to said developing agent.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Dry Development In Electrophotography (AREA)
US88378A 1969-11-11 1970-11-10 Method and apparatus for supplementing toner in electrophotographic machines Expired - Lifetime US3698926A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9061269 1969-11-11

Publications (1)

Publication Number Publication Date
US3698926A true US3698926A (en) 1972-10-17

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ID=14003288

Family Applications (1)

Application Number Title Priority Date Filing Date
US88378A Expired - Lifetime US3698926A (en) 1969-11-11 1970-11-10 Method and apparatus for supplementing toner in electrophotographic machines

Country Status (6)

Country Link
US (1) US3698926A (enrdf_load_stackoverflow)
AU (1) AU2215270A (enrdf_load_stackoverflow)
CA (1) CA939732A (enrdf_load_stackoverflow)
DE (1) DE2055321C3 (enrdf_load_stackoverflow)
FR (1) FR2069358A5 (enrdf_load_stackoverflow)
NL (1) NL7016420A (enrdf_load_stackoverflow)

Cited By (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3778148A (en) * 1971-12-27 1973-12-11 Fuji Xerox Co Ltd Apparatus and method for selectively discharging the photoconductive surface of an electrostatic drum copier to facilitate the cleaning thereof
US3821938A (en) * 1971-12-17 1974-07-02 Ibm Toner usage sensing system
JPS5019459A (enrdf_load_stackoverflow) * 1973-06-20 1975-02-28
US3880119A (en) * 1973-12-20 1975-04-29 Xerox Corp Development apparatus
US3893408A (en) * 1973-12-26 1975-07-08 Xerox Corp Toner dispensing system
US3923004A (en) * 1973-12-27 1975-12-02 Xerox Corp Development and cleaning apparatus for reverse path machine
JPS5119540A (en) * 1974-07-17 1976-02-16 Savin Business Machines Corp Choshokuzainonodokanshi oyobi hokyusochi
US3948218A (en) * 1973-11-30 1976-04-06 Agfa-Gevaert, A.G. Electrostatic copier device
US3956108A (en) * 1973-07-30 1976-05-11 Xerox Corporation Anti-plugging device for automatic developability control systems
US3999687A (en) * 1974-07-17 1976-12-28 Savin Business Machines Corporation Toner concentration detector
US4017170A (en) * 1972-04-13 1977-04-12 Canon Kabushiki Kaisha Electrophotographic device
US4034701A (en) * 1972-06-28 1977-07-12 Xerox Corporation Particle dispenser
US4131081A (en) * 1976-04-14 1978-12-26 Hitachi, Ltd. Toner concentration detecting apparatus
US4321886A (en) * 1979-09-19 1982-03-30 Tokyo Shibaura Denki Kabushiki Kaisha Apparatus for controlling toner concentration
US4330193A (en) * 1979-10-01 1982-05-18 Xerox Corporation Development system
US4333124A (en) * 1976-10-18 1982-06-01 Canon Kabushiki Kaisha Electrically discharging method and device
EP0086516A1 (en) * 1982-02-11 1983-08-24 Agfa-Gevaert N.V. Xerographic copying apparatus
US4405226A (en) * 1980-07-23 1983-09-20 Mita Industrial Company Limited Developing material supplying control device for electrostatic copying apparatus
US4423948A (en) 1980-07-23 1984-01-03 Mita Industrial Company Limited Dual component developing material detecting device for electrostatic copying apparatus
US4436411A (en) 1980-04-15 1984-03-13 Mita Industrial Co., Ltd. Toner dispenser and detector for an electrostatic copying apparatus
WO1984002202A1 (en) * 1982-11-29 1984-06-07 Hitachi Metals Ltd Apparatus for controlling toner concentration in developer
US4640129A (en) * 1977-02-28 1987-02-03 Seiichi Miyakawa Method and apparatus for detecting toner concentration of two-component dry developer
US4952301A (en) * 1989-11-06 1990-08-28 Betz Laboratories, Inc. Method of inhibiting fouling in caustic scrubber systems
US5003352A (en) * 1989-10-24 1991-03-26 Am International, Inc. Liquid toner supply system and method
US5017964A (en) * 1989-11-29 1991-05-21 Am International, Inc. Corona charge system and apparatus for electrophotographic printing press
US5019868A (en) * 1989-12-28 1991-05-28 Am International, Inc. Developer electrode and reverse roller assembly for high speed electrophotographic printing device
US5077172A (en) * 1989-12-28 1991-12-31 Am International, Inc. Carrier web transfer device and method for electrophotographic printing press
US5166729A (en) * 1991-08-30 1992-11-24 Xerox Corporation Toner concentration sensing apparatus
US5177877A (en) * 1989-12-28 1993-01-12 Am International, Inc. Dryer-fuser apparatus and method for high speed electrophotographic printing device
US5214476A (en) * 1990-11-16 1993-05-25 Sanyo Electric Co., Ltd. Image forming apparatus
US20070264053A1 (en) * 2006-05-15 2007-11-15 Nobuo Iwata Developing device including improved conveying device, process cartridge and image forming apparatus using the same

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2363757C2 (de) * 1973-12-21 1983-07-14 Hoechst Ag, 6230 Frankfurt Verfahren und Vorrichtung zum Nachdosieren von Entwicklermedium
US4270487A (en) * 1977-10-27 1981-06-02 Hitachi, Ltd. Developer regulating device in developing apparatus

Cited By (35)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3821938A (en) * 1971-12-17 1974-07-02 Ibm Toner usage sensing system
US3778148A (en) * 1971-12-27 1973-12-11 Fuji Xerox Co Ltd Apparatus and method for selectively discharging the photoconductive surface of an electrostatic drum copier to facilitate the cleaning thereof
US4017170A (en) * 1972-04-13 1977-04-12 Canon Kabushiki Kaisha Electrophotographic device
US4034701A (en) * 1972-06-28 1977-07-12 Xerox Corporation Particle dispenser
JPS5019459A (enrdf_load_stackoverflow) * 1973-06-20 1975-02-28
US3956108A (en) * 1973-07-30 1976-05-11 Xerox Corporation Anti-plugging device for automatic developability control systems
US3948218A (en) * 1973-11-30 1976-04-06 Agfa-Gevaert, A.G. Electrostatic copier device
US3880119A (en) * 1973-12-20 1975-04-29 Xerox Corp Development apparatus
US3893408A (en) * 1973-12-26 1975-07-08 Xerox Corp Toner dispensing system
US3923004A (en) * 1973-12-27 1975-12-02 Xerox Corp Development and cleaning apparatus for reverse path machine
JPS5119540A (en) * 1974-07-17 1976-02-16 Savin Business Machines Corp Choshokuzainonodokanshi oyobi hokyusochi
US3999687A (en) * 1974-07-17 1976-12-28 Savin Business Machines Corporation Toner concentration detector
US3970036A (en) * 1974-07-17 1976-07-20 Savin Business Machines Corporation Toner concentration detector for dry powder magnetic brush toning system
US4131081A (en) * 1976-04-14 1978-12-26 Hitachi, Ltd. Toner concentration detecting apparatus
US4333124A (en) * 1976-10-18 1982-06-01 Canon Kabushiki Kaisha Electrically discharging method and device
US4640129A (en) * 1977-02-28 1987-02-03 Seiichi Miyakawa Method and apparatus for detecting toner concentration of two-component dry developer
US4321886A (en) * 1979-09-19 1982-03-30 Tokyo Shibaura Denki Kabushiki Kaisha Apparatus for controlling toner concentration
US4330193A (en) * 1979-10-01 1982-05-18 Xerox Corporation Development system
US4436411A (en) 1980-04-15 1984-03-13 Mita Industrial Co., Ltd. Toner dispenser and detector for an electrostatic copying apparatus
US4405226A (en) * 1980-07-23 1983-09-20 Mita Industrial Company Limited Developing material supplying control device for electrostatic copying apparatus
US4423948A (en) 1980-07-23 1984-01-03 Mita Industrial Company Limited Dual component developing material detecting device for electrostatic copying apparatus
EP0086516A1 (en) * 1982-02-11 1983-08-24 Agfa-Gevaert N.V. Xerographic copying apparatus
US4519696A (en) * 1982-02-11 1985-05-28 Agfa-Gevaert N. V. Xerographic copying apparatus
WO1984002202A1 (en) * 1982-11-29 1984-06-07 Hitachi Metals Ltd Apparatus for controlling toner concentration in developer
US4592645A (en) * 1982-11-29 1986-06-03 Hitachi Metals, Ltd. Apparatus for controlling concentration of toner in developer
US5003352A (en) * 1989-10-24 1991-03-26 Am International, Inc. Liquid toner supply system and method
US4952301A (en) * 1989-11-06 1990-08-28 Betz Laboratories, Inc. Method of inhibiting fouling in caustic scrubber systems
US5017964A (en) * 1989-11-29 1991-05-21 Am International, Inc. Corona charge system and apparatus for electrophotographic printing press
US5019868A (en) * 1989-12-28 1991-05-28 Am International, Inc. Developer electrode and reverse roller assembly for high speed electrophotographic printing device
US5077172A (en) * 1989-12-28 1991-12-31 Am International, Inc. Carrier web transfer device and method for electrophotographic printing press
US5177877A (en) * 1989-12-28 1993-01-12 Am International, Inc. Dryer-fuser apparatus and method for high speed electrophotographic printing device
US5214476A (en) * 1990-11-16 1993-05-25 Sanyo Electric Co., Ltd. Image forming apparatus
US5166729A (en) * 1991-08-30 1992-11-24 Xerox Corporation Toner concentration sensing apparatus
US20070264053A1 (en) * 2006-05-15 2007-11-15 Nobuo Iwata Developing device including improved conveying device, process cartridge and image forming apparatus using the same
US7783233B2 (en) * 2006-05-15 2010-08-24 Ricoh Company, Ltd. Developing device including improved conveying device, process cartridge and image forming apparatus using the same

Also Published As

Publication number Publication date
CA939732A (en) 1974-01-08
DE2055321B2 (de) 1973-08-02
AU2215270A (en) 1972-05-18
FR2069358A5 (enrdf_load_stackoverflow) 1971-09-03
DE2055321A1 (de) 1971-07-01
NL7016420A (enrdf_load_stackoverflow) 1971-05-13
DE2055321C3 (de) 1975-11-20

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