US3233781A - Toner control system - Google Patents

Toner control system Download PDF

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Publication number
US3233781A
US3233781A US278815A US27881563A US3233781A US 3233781 A US3233781 A US 3233781A US 278815 A US278815 A US 278815A US 27881563 A US27881563 A US 27881563A US 3233781 A US3233781 A US 3233781A
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United States
Prior art keywords
toner
mixture
light
carrier
bridge
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
US278815A
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English (en)
Inventor
William J Grubbs
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.)
Wells Fargo Capital Finance LLC
Original Assignee
Savin Business Machines Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Savin Business Machines Corp filed Critical Savin Business Machines Corp
Priority to US278815A priority Critical patent/US3233781A/en
Priority to GB17882/64A priority patent/GB1066831A/en
Priority to DES90912A priority patent/DE1261758B/de
Priority to FR973329A priority patent/FR1393008A/fr
Priority to CH602864A priority patent/CH438949A/de
Priority to NL6405108A priority patent/NL6405108A/xx
Application granted granted Critical
Publication of US3233781A publication Critical patent/US3233781A/en
Anticipated expiration legal-status Critical
Assigned to FOOTHILL CAPITAL CORPORATION, A CA. CORP. reassignment FOOTHILL CAPITAL CORPORATION, A CA. CORP. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: SAVIN CORPORATION
Expired - Lifetime legal-status Critical Current

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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G9/00—Developers
    • 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
    • G03G15/0855—Detection or control means for the developer concentration the concentration being measured by optical means
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
    • G03G15/10—Apparatus for electrographic processes using a charge pattern for developing using a liquid developer
    • G03G15/104—Preparing, mixing, transporting or dispensing developer
    • G03G15/105—Detection or control means for the toner concentration
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D11/00—Control of flow ratio
    • G05D11/02—Controlling ratio of two or more flows of fluid or fluent material
    • G05D11/13—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means
    • G05D11/131—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means by measuring the values related to the quantity of the individual components
    • G05D11/133—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means by measuring the values related to the quantity of the individual components with discontinuous action
    • G05D11/134—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means by measuring the values related to the quantity of the individual components with discontinuous action by sensing the weight of the individual components
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S222/00—Dispensing
    • Y10S222/01—Xerography

Definitions

  • My invention relates to a toner control system and more particularly to a system for accurately regulating the proportion of toner to carrier in an electrostatic copying machine.
  • the electrical charge flows from the photoconductive surface in proportion to the light incident upon a given area.
  • the result of this action is a latent electrostatic image on the surface which carries the photoconductive coating.
  • the latent electrostatic image suitably charged particles are applied to the surface.
  • The. particles are so charged as to electrostatically adhere to the latent charged image on the carrier.
  • This powdered material or toner is so pigmented as to contrast with the material of the coating to produce the desired visible image.
  • the image can be set by the action of heat, for example, to cause the toner particles to fuse into the coating material.
  • My toner control system permits the relative percentage of toner to carrier to be controlled with a high degree of accuracy.
  • My system permits the percentage of toner to carrier to be maintained at a relatively constant value.
  • a machine incorporating my] toner control system is able to produce excellent copies with a high degree of accuracy over a relatively long period of time.
  • My system is relatively simple for the desirable result achieved thereby.
  • One object of my invention is to provide a toner control system for controlling with a high degree of accuracy the percentage of toner to carrier in an electrostatic copying machine.
  • Another object of my invention is to provide a toner control system which maintains the percentage of tone to carrier in an electrostatic copying machine at a relatively constant value.
  • a further object of my invention is to provide a toner control system for an electrostatic copying machine which permits the machine to make copies of goodquality with a high degree of accuracy over a relatively long period of time.
  • Still another object of my invention is to provide a toner control system which is relatively simple for the result achieved thereby.
  • my invention contemplates the provision of a toner control system including means for continuously monitoring the mixture of toner and carrier in an electrostatic copying machine to determine the relative proportion of toner and carrier. Means responsive to the monitoring system adds toner to the mixture in proportion to the amount which has been withdrawn from the supply in the course of making copies.
  • FIGURE 1 is a schematic view illustrating one form of my toner control system.
  • FIGURE 2 is a schematic view of an alternate form of my toner control system.
  • FIGURE 3 is a schematic view of an alternate form of the electrical circuit of my toner control system.
  • FIGURE 1 of the drawings one form of my toner control system is adapted to be applied to an electrostatic copying machine (not shown) of a suitable type known to the art including a reservoir 10 holding a supply 12 of a mixture of powdered toner and powdered carrier.
  • Suitable materials for use as toners and carriers are known in the art.
  • a direct or a reversed image can be obtained either by using the same carrier and choosing toner powder to give the image desired or by using the same toner and varying the carrier so as to give the desired image.
  • toners which can be employed are asphaltum, dragons blood, zein powder, vinsol powder, resin powder and other powders which are known as electroscopic powders.
  • the carriers employed are generally magnetic materials. Alternatively, they may be granular materials having a cubic, rhombic, hexagonal or tetragonal crystalline structure. Some specific materials which have been found suitable are sodium chloride, ammonium chloride, aluminum potassium chloride, rochelle salt, sodium nitrate, aluminum nitrate, potassium chlorate, methyl methacrylate resin, granular zircon and other such materials.
  • the particle size of the carriers can vary from '50 to +325 mesh with the optimum size being within the range from 100 to +140 mesh.
  • the surfaces of the carriers can be left as is or they may be chemically treated to produce a desired triboelectric relationship with the particular toner used.
  • the toners which are dyed or pigmented resinaceous powders are so chosen as to maintain a specific triboelectric relationship with the particular carrier being employed.
  • the particle size range of the toners may vary from 1 to 50 microns with the optimum range being from 5 to 20 microns. It will readily be understood that the percentage by weight of toner to carrier will vary from machine to machine. However, in any given machine there exists an optimum range which will .produce the best picture with the least background. Generally speaking, the toner may vary from about 1.5% to 12.5% by weight to carrier with the optimum range being from about 1.5 by weight to about 4% by weight.
  • positive and negative as aplied to toners which are used to develop elec trostatic latent images created through an electrophotographic or electrostatic process have come to mean that a positive toner is a material which in combination with a carrier will give an exact or direct copy of the original item.
  • a negative toner in combination with a particular carrier will give a reversed copy of the original item.
  • Positive and negative toners are chosen with reference to a particular carrier. If an attempt is being made to develop an electrostatic image of negative charge so as to obtain a direct copy of the original item, a toner-carrier combination would be chosen which will produce a posi-' tive charge on the toner so as to be attracted to the image areas.
  • a toner-carrier combination would be chosen which will develop a negative charge on the toner so as to be repelled from the image to the nonimage areas. Consequently, where the electrostatic image is negative a positive toner has a positive charge whereas a negative toner has a negative charge. However, where the electrostatic image is positively charged then a positive toner has a negative charge and a negative toner has a positive charge. It will readily be appreciated from the following explanation that my toner control system operates with any combination of toner and carrier without regard to the fact of whether a positive toner or a negative toner is being used.
  • the carrier and toner must be so related on the triboelectric scale that the toner acquires a positive charge when the particles are tumbled.
  • the potential difference in the charges developed by two contacting dielectrics is proportional to the difference between their dielectric constants, the material having a greater constant becoming positive.
  • the mixture 12 may be applied to the latent electrostatieimage in any suitable manner.
  • a roller and a magnet may be employed to pick up particles from the mixture and, at the point of contact between the roller and the image, the toner particles will be transferred to the image while the carrier particles remain on the roller.
  • Any suitable means is employed to agitate the mixture 12 constantly so that the carrier and toner particles are thoroughly mixed at all points throughout the reservoir.
  • the casing holding the mixture 12 has a window 14 in a wall 16 thereof so that particles of the mixture 12 are visible from outside the casing.
  • I connect a lamp 18 across the terminals 20 and 22 of a suitable source of voltage to light the lamp to produce a beam 24 of light which travels from the lamp and through the window 14 so as to impinge on the mixture 12 within the reservoir 10.
  • the toner particles are darker than are the carrier particles.
  • the amount of light from the beam 24 which is reflected from the mixture 12 will be a measure of the reflectivity of the mixture.
  • I provide my system with a means for measuring any change in intensity of the beam 26.
  • I connect respective resistors 28 and '50 and two light-sensitive elements 32 and 34 in a Wheatstone bridge.
  • I select the resistors 28 and 30 to be of substantially the same value and select the devices 32 and 34 to be as nearly identical as is possible.
  • These devices 32 and 34 may for example be suitable semiconductor photoconductive elements. As is known in the art, these devices become more conductive as the amount of light impinging thereon increases.
  • I connect a suitable source of potential such as a battery 36 across the input terminals 38 and 40 of the Wheatstone bridge. As is known in the art, when the bridge is unbalanced a potential difference exists across the output terminals 42 and 44 of the bridge.
  • I position the device 32 within a housing or shield 46 to prevent any of the reflected light of beam 26 from reaching this device while permitting light represented by a beam 48 from lamp 18 to impinge on the device.
  • I connect a resistor 50 across the device 34 and provide a brush 52 which can be positioned to balance the bridge including resistors 28 and 30 and devices 32 and 34 when the mixture 12 has the desired proportion of toner to carrier.
  • j When the bridge is balanced there is no difference in potential across the output terminals 42 and 44 of the bridge.
  • My toner control system includes a transistor 54 having a base 56 connected to terminal 44, an emitter 58 connected to terminal 42 and a collector 60.
  • Transistor 54 is a p-n-p transistor which will conduct when the base 56 is at a lower potential than is the emitter 58. This condition results when the output terminal 44 of the bridge is at a lower potential than is the output terminal 42.
  • I connect a battery 62 and a relay winding 64 in the collector circuit of the transistor 54.
  • win-ding 64 is energized to cause its armature 66 to close a normally open switch 68 to complete the circuit of a solenoid 70 to a source having terminals 72 and 74.
  • My toner control system includes a hopper 76 containing a supply of toner.
  • a guide 78 carries a bracket 80 which supports a plug 82 which fits into a seat formed by beveling the lower end of the outlet 84 of the hopper 76.
  • a spring 86 normally positions the guide 78 at a location at which the plug 82 closes the outlet 84.
  • Solenoid 70 has an armature 88 pivotally connected to a lever 90 rotatably supported on a pin 92 carried by a bracket 94 on the hopper.
  • the other end of lever 9tl' is forked to provide arms having slotted ends which engage pins 96 on the guide 78.
  • the solenoid 70' When the solenoid 70' is energized, it draws its armature upwardly as viewed in FIGURE 1 to rotate the lever 90 in a counterclockwise direction to move the plug 82 and the guide 78'- downwardly. In this position of the parts, toner is per-- mitted to flow out of the hopper 76 and through the guide 78 into the casing 10. It will be seen that the guide 78 extends through an opening 98 in casing 10.
  • I provide my control system with means for changing the relative proportion of toner to carrier in the mixture 12. I accomplish this by connecting a variable resistor having a resistance winding 100 and a brush 102 across the resistor 28. It will readily be seen that as I decrease the amount of resistance of winding 100 in the circuit, I add more toner to the mixture 12. Once this value has been set and the light balancing resistor 50 has been adjusted, then this system operates to maintain the average proportion of toner to carrier at a relatively constant value over a long period of operation of the machine.
  • the developer may be an emulsion consisting of immiscible fiuid carrier and toner phases, the latter being composed of a suspension of developer particles in an insulating liquid.
  • the toner particles are carried on the surface of globules of the fluid carrier phase.
  • the liquid developer may be adispersion of finely divided opaque particles such, for example, as carbon, colored resins and glass in an insulating liquid.
  • the developer may also be a suspension of carbon black in kerosene or another suitable dielectric liquid. It has also been suggested that nonflammable, nontoxic developers be provided.
  • trichloromonofluoromethane or trichlorotrifluoroethane are used with a coloring matter such as phthalocyanine blue and a fixative such as an alkyd resin.
  • a coloring matter such as phthalocyanine blue
  • a fixative such as an alkyd resin
  • FIGURE 2 I have shown a form of my toner control system which is particularly adapted to controlling the amount of toner in a liquid developer.
  • the tank It contains a liquid developer 194 of the type mentioned hereinabove.
  • Any suitable apparatus similar to that discussed hereinabove in connection with the form of my invention shown in FIGURE 1 and adapted to dispense the toner can be employed with the apparatus shown in FIGURE 2.
  • Suitable liquid agitating apparatus is used to keep the developer 104 uniformly mixed throughout the tank
  • I employ a liquid developer rather than relying on the refiectivity of the developer as in the form of my invention shown in FIGURE 1, I rely on the light transmitting properties of the developer.
  • FIGURE 3 I have shown an alternate form of my invention which is somewhat simpler and less expensive than is the particular arrangement illustrated in FIGURE 1. It will readily be apparent that in the form of my invention shown in FIGURE 3, I replace the battery 36 with a transformer winding 108 having a capacitor 116 connected thereacross for supplying potential to the bridge through a rectifier 112. A similar arrangement of a winding 114, a rectifier 116 and a capacitor 118 replaces the battery 62 while a winding 120 supplies potential to the lamp 18. This arrangement requires less space, weighs less and has a longer life without servicing than does the form of my invention shown in FIGURE 1.
  • the base of transistor 54 is at a lower potential than is the emitter 58 so that the transistor conducts to energize winding 64 to close switch 63 to energize solenoid 70 to rock lever to move plug 82 away from its seat to permit toner to fall into the reservoir 10.
  • this additional toner falls into the reservoir, it is immediately mixed with the carrier so that the amount of light refiected as represented by beam 26 is reduced and the conductivity of the device 34 decreases. Owing to this decrease in conductivity of the device 34, the potential at point 44 rises until transistor 54 cuts off to deenergize winding 64 to cause switch 68 to open so that solenoid 70 is deenergized and spring 86 moves the plug 82 back into engagement with its seat. It will readily be seen that my system adds to the mixture 12 substantially as much toner as has been taken away in the course of operation of the machine.
  • I reduce the amount of resistance introduced into the circuit by resistor so that the potential of the emitter 58 rises to turn the transistor on to increase the amount of toner in the mixture until the resistance of the device 34 increases to a point at which the transistor 54 cuts off.
  • To decrease the proportion of toner I increase the amount of resistance introduced into the circuit by resistor 100 and allow normal operation of the machine to reduce the proportion of toner.
  • FIGURE 3 The operation of the form of my invention shown in FIGURE 3 is substantially the same as that outlined above in connection with the form of my invention shown in FIGURE 1.
  • the diiference between the two arrangements is that where my system is used on a machine which operates with liquid developer then I prefer to rely on the transmissivity of the developer rather than on its reflectivity.
  • I employ a circuit of the type shown in FIGURE 3 owing to practical considerations.
  • Apparatus for regulating the relative proportion of mixed materials having divergent optical characteristics including in combination a container for holding a supply of a mixture of said materials in a predetermined relative proportion, a bridge comprising a pair of light-sensitive arms, a source of light positioned adjacent said container to direct light toward said supply, means comprising a shield disposed between said arms to direct light from said source directly to one of said arms and from said material to the other of said arms, means normally balancing said bridge when said materials are in said predetermined relative proportion and means responsive to unbalance of said bridge for regulating said mixture to said predetermined portion.
  • Apparatus for regulating the relative proportion of mixed materials having divergent optical characteristics including in combination a container holding a supply of a mixture of said materials in a predetermined relative proportion, a bridge circuit comprising a light-responsive arm, means for directing light to said mixture and from said mixture to said light-responsive arm, means for balancing said bridge when the light directed to said element corresponds to said predetermined relative proportion and means responsive to unbalance of said bridge when light directed to said light-responsive arm deviates from that corresponding to said predetermined relative proportion for regulating said mixture to said predetermined proportion.
  • Apparatus for regulating the relative proportion of mixed materials having divergent optical characteristics including in combination a container holding a supply of a mixture of said materials in a predetermined relative proportion, a bridge comprising a light-responsive arm and a variable control arm, means for directing light to said mixture and from said mixture to said light-responsive arm, means comprising said control arm for balancing said bridge when the light directed from said mixture to said light-responsive arm corresponds to said predetermined relative proportion and means responsive to unbalance of said bridge for regulating said mixture to said predetermined proportion, said control arm being adapted to be varied to change said predetermined proportion.
  • Apparatus for regulating the relative proportion of mixed materials having divergent optical characteristics including in combination a container holding a supply of a mixture of said materials in a predetermined relative proportion, a bridge comprising a pair of respective lightsensitive arms, a source of light, means for directing light from said source directly to one of said light-sensitive arms and from said source to said mixture and from said mixture to said other light-sensitive arm, means comprising a light-balancing resistor for normally balancing said bridge when the light from said mixture to said other arm corresponds to said predetermined proportion and means responsive to an unbalance of said bridge for regulating said mixture to said predetermined proportion.
  • Apparatus for regulating the relative proportion of a mixture of a relatively light carrier material and a relatively dark toner material including in combination a container holding a supply of a mixture of said materials in a predetermined relative proportion, a bridge comprising a photoconductive element in one of the arms of said bridge, a light source, means for directing light from said source to said mixture, means mounting said photoconductive element in a position to receive reflected light from said mixture, means normally balancing said bridge when the reflected light from said mixture corresponds to said predetermined proportion and means responsive to unbalance of said bridge for regulating said mixture to said predetermined proportion.
  • Apparatus for regulating the relative proportion of mixed materials having divergent optical characteristics including in combination a container holding a supply of a mixture of said materials in a predetermined relative proportion, a bridge including a first arm comprising variable control impedance, a second arm comprising a first light-sensitive element and a third arm comprising a second light-sensitive element and a light-balancing impedance, a source of light, means for directing light from said source directly to one of said light-sensitive elements and for directing light from said source to said mixture and from said mixture to the other light-sensitive element, means comprising said variable control impedance and said light-balancing impedance for normally balancing said bridge when said mixture is in said predetermined proportion and means responsive to unbalance of said bridge for regulating said mixture to said predetermined proportion, said variable control resistor being adapted to be varied to change said predetermined proportion.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Wet Developing In Electrophotography (AREA)
  • Developing Agents For Electrophotography (AREA)
US278815A 1963-05-08 1963-05-08 Toner control system Expired - Lifetime US3233781A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
US278815A US3233781A (en) 1963-05-08 1963-05-08 Toner control system
GB17882/64A GB1066831A (en) 1963-05-08 1964-04-29 Electrostatic copying apparatus
DES90912A DE1261758B (de) 1963-05-08 1964-05-04 Elektrophotographisches Kopiergeraet
FR973329A FR1393008A (fr) 1963-05-08 1964-05-05 Système de réglage pour substance de développement
CH602864A CH438949A (de) 1963-05-08 1964-05-08 Einrichtung zur Regelung der Anteile von unterschiedlich stark lichtreflektierenden oder lichtdurchlässigen Materialien einer Mischung
NL6405108A NL6405108A (fr) 1963-05-08 1964-05-08

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Application Number Priority Date Filing Date Title
US278815A US3233781A (en) 1963-05-08 1963-05-08 Toner control system

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US3233781A true US3233781A (en) 1966-02-08

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US278815A Expired - Lifetime US3233781A (en) 1963-05-08 1963-05-08 Toner control system

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US (1) US3233781A (fr)
CH (1) CH438949A (fr)
DE (1) DE1261758B (fr)
FR (1) FR1393008A (fr)
GB (1) GB1066831A (fr)
NL (1) NL6405108A (fr)

Cited By (50)

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US3348522A (en) * 1962-08-28 1967-10-24 Xerox Corp Automatic toner control system
US3348523A (en) * 1965-04-07 1967-10-24 Xerox Corp Automatic toner control system
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US3369524A (en) * 1964-08-28 1968-02-20 Lumoprint Zindler Kg Copying device for electro-photographic copying materials
US3376853A (en) * 1966-04-29 1968-04-09 Xerox Corp Electrostatic toner control
US3399652A (en) * 1967-06-14 1968-09-03 Addressograph Multigraph Automatic toner concentrate detector
US3430606A (en) * 1968-01-02 1969-03-04 Xerox Corp Electroscopic particle sensor
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US3435238A (en) * 1965-01-28 1969-03-25 Sun Oil Co Catalyst analysis apparatus
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US3466450A (en) * 1966-08-04 1969-09-09 William L Goodman Swimming pool chlorine concentration controller using reference resistor in control circuit
US3494328A (en) * 1966-09-01 1970-02-10 Addressograph Multigraph Liquid photoelectrostatic developer unit
US3527651A (en) * 1966-10-20 1970-09-08 Addressograph Multigraph Method of and apparatus for developing electrostatic images
US3610205A (en) * 1968-10-17 1971-10-05 Continental Can Co Apparatus for measuring and controlling mixture content
US3663859A (en) * 1967-10-25 1972-05-16 Shinji Saito Sensitive light and smoke detecting device with memory system
US3682132A (en) * 1969-03-03 1972-08-08 Xerox Corp Automatic developer controller
US3727065A (en) * 1969-10-17 1973-04-10 Xerox Corp Automatic developability control system
US3728549A (en) * 1972-04-12 1973-04-17 Us Navy In situ device for measuring light scattering
US3756192A (en) * 1971-12-17 1973-09-04 Ibm Automatic toner concentration control system
US3757999A (en) * 1969-10-17 1973-09-11 Xerox Corp Automatic developability control system for electrostatic recording apparatus
US3765654A (en) * 1968-10-17 1973-10-16 Continental Can Co System for measuring and controlling mixture content
US3777173A (en) * 1972-02-22 1973-12-04 Dyke Res Van Xerographic toner concentration measuring apparatus and method
US3780299A (en) * 1971-08-06 1973-12-18 Kalle Ag Device for the production of a measuring signal or control
US3791744A (en) * 1972-02-22 1974-02-12 Dyk Res Corp Van Xerographic toner concentration measuring apparatus and method
US3802381A (en) * 1968-07-30 1974-04-09 Continental Can Co Apparatus for measuring concentration ratios of a mixture of materials
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US4370053A (en) * 1980-01-19 1983-01-25 Canon Kabushiki Kaisha Developer supply device
US4389972A (en) * 1979-08-04 1983-06-28 Ricoh Company, Ltd. Toner concentration control apparatus
US4431300A (en) * 1982-02-16 1984-02-14 Xerox Corporation Automatic developability sensing in electrophotographic printing
US4465356A (en) * 1982-03-08 1984-08-14 Eastman Kodak Company Magnetic brush developer apparatus
US4551004A (en) * 1980-10-21 1985-11-05 Xerox Corporation Toner concentration sensor
US4579253A (en) * 1977-05-17 1986-04-01 Savin Corporation Toner control system
US4595277A (en) * 1983-02-01 1986-06-17 Andrzej Maczuszenko Toner supply control system
US4706032A (en) * 1986-03-17 1987-11-10 Eastman Kodak Company Toner concentration monitor
EP0259448A1 (fr) * 1986-02-14 1988-03-16 Spectrum Sciences Bv Regulation du repartiteur de charge dans un revelateur liquide.
US4860924A (en) * 1986-02-14 1989-08-29 Savin Corporation Liquid developer charge director control
WO1994001809A1 (fr) * 1992-07-02 1994-01-20 Indigo N.V. Detecteur de la concentration d'un toner colore
US5318431A (en) * 1984-07-13 1994-06-07 Xerox Corporation Process and apparatus for preparing toner particles
US5530521A (en) * 1993-05-24 1996-06-25 Samsung Electronics Co., Ltd. Apparatus and method for sensing state of a waste toner box of system in an electrophotographic reproduction apparatus
US20040093995A1 (en) * 2002-07-22 2004-05-20 Bobby Hu Ratcheting wrench with quick tightening/loosening functions and fine adjusting functions
US20090297179A1 (en) * 2008-05-27 2009-12-03 Xerox Corporation Toner concentration system control with state estimators and state feedback methods

Families Citing this family (4)

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US3348521A (en) * 1962-08-28 1967-10-24 Xerox Corp Automatic toner control system
US3348522A (en) * 1962-08-28 1967-10-24 Xerox Corp Automatic toner control system
US3369524A (en) * 1964-08-28 1968-02-20 Lumoprint Zindler Kg Copying device for electro-photographic copying materials
US3435238A (en) * 1965-01-28 1969-03-25 Sun Oil Co Catalyst analysis apparatus
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US3452208A (en) * 1966-03-29 1969-06-24 Us Air Force Automatic liquid level detector,using reflection from the meniscus
US3376853A (en) * 1966-04-29 1968-04-09 Xerox Corp Electrostatic toner control
US3466450A (en) * 1966-08-04 1969-09-09 William L Goodman Swimming pool chlorine concentration controller using reference resistor in control circuit
US3494328A (en) * 1966-09-01 1970-02-10 Addressograph Multigraph Liquid photoelectrostatic developer unit
US3527651A (en) * 1966-10-20 1970-09-08 Addressograph Multigraph Method of and apparatus for developing electrostatic images
US3431050A (en) * 1967-01-04 1969-03-04 Ibm Combination paper and developer supply
US3399652A (en) * 1967-06-14 1968-09-03 Addressograph Multigraph Automatic toner concentrate detector
US3663859A (en) * 1967-10-25 1972-05-16 Shinji Saito Sensitive light and smoke detecting device with memory system
US3430606A (en) * 1968-01-02 1969-03-04 Xerox Corp Electroscopic particle sensor
US3802381A (en) * 1968-07-30 1974-04-09 Continental Can Co Apparatus for measuring concentration ratios of a mixture of materials
US3610205A (en) * 1968-10-17 1971-10-05 Continental Can Co Apparatus for measuring and controlling mixture content
US3765654A (en) * 1968-10-17 1973-10-16 Continental Can Co System for measuring and controlling mixture content
US3682132A (en) * 1969-03-03 1972-08-08 Xerox Corp Automatic developer controller
US3727065A (en) * 1969-10-17 1973-04-10 Xerox Corp Automatic developability control system
US3757999A (en) * 1969-10-17 1973-09-11 Xerox Corp Automatic developability control system for electrostatic recording apparatus
US3881112A (en) * 1970-09-16 1975-04-29 Gordon A Roberts Smoke and heat detector unit
US3924462A (en) * 1971-08-06 1975-12-09 Hoechst Ag Method of measuring the toner concentration of a developer circulating in an electrophotographic reproduction machine
US3780299A (en) * 1971-08-06 1973-12-18 Kalle Ag Device for the production of a measuring signal or control
US3830401A (en) * 1971-12-13 1974-08-20 Eastman Kodak Co Toner concentration monitoring apparatus
US3756192A (en) * 1971-12-17 1973-09-04 Ibm Automatic toner concentration control system
US3791744A (en) * 1972-02-22 1974-02-12 Dyk Res Corp Van Xerographic toner concentration measuring apparatus and method
US3777173A (en) * 1972-02-22 1973-12-04 Dyke Res Van Xerographic toner concentration measuring apparatus and method
US3728549A (en) * 1972-04-12 1973-04-17 Us Navy In situ device for measuring light scattering
US3928764A (en) * 1972-06-02 1975-12-23 Hoechst Ag Method and apparatus for measuring and controlling the toner concentration in electrophotographic reproduction machines
US3931526A (en) * 1973-04-13 1976-01-06 Aerazur Constructions Aeronautiques Process and a device for measuring transmission factors
US3970036A (en) * 1974-07-17 1976-07-20 Savin Business Machines Corporation Toner concentration detector for dry powder magnetic brush toning system
US4088092A (en) * 1976-04-28 1978-05-09 Ricoh Co., Ltd. Toner density sensing apparatus for electrostatic copying machine
US4579253A (en) * 1977-05-17 1986-04-01 Savin Corporation Toner control system
US4141645A (en) * 1977-07-29 1979-02-27 Eastman Kodak Company Toner concentration monitor
US4389972A (en) * 1979-08-04 1983-06-28 Ricoh Company, Ltd. Toner concentration control apparatus
US4310238A (en) * 1979-09-08 1982-01-12 Ricoh Company, Ltd. Electrostatic copying apparatus
US4370053A (en) * 1980-01-19 1983-01-25 Canon Kabushiki Kaisha Developer supply device
US4332467A (en) * 1980-02-27 1982-06-01 Mita Industrial Co., Ltd. Developing device in electrostatic copying apparatus
US4551004A (en) * 1980-10-21 1985-11-05 Xerox Corporation Toner concentration sensor
US4431300A (en) * 1982-02-16 1984-02-14 Xerox Corporation Automatic developability sensing in electrophotographic printing
US4465356A (en) * 1982-03-08 1984-08-14 Eastman Kodak Company Magnetic brush developer apparatus
US4595277A (en) * 1983-02-01 1986-06-17 Andrzej Maczuszenko Toner supply control system
US5318431A (en) * 1984-07-13 1994-06-07 Xerox Corporation Process and apparatus for preparing toner particles
EP0259448A1 (fr) * 1986-02-14 1988-03-16 Spectrum Sciences Bv Regulation du repartiteur de charge dans un revelateur liquide.
EP0259448A4 (fr) * 1986-02-14 1988-07-04 Spectrum Sciences Bv Regulation du repartiteur de charge dans un revelateur liquide.
US4860924A (en) * 1986-02-14 1989-08-29 Savin Corporation Liquid developer charge director control
US4706032A (en) * 1986-03-17 1987-11-10 Eastman Kodak Company Toner concentration monitor
WO1994001809A1 (fr) * 1992-07-02 1994-01-20 Indigo N.V. Detecteur de la concentration d'un toner colore
US5570193A (en) * 1992-07-02 1996-10-29 Indigo N.V. Concentration detector for colored toner
US5530521A (en) * 1993-05-24 1996-06-25 Samsung Electronics Co., Ltd. Apparatus and method for sensing state of a waste toner box of system in an electrophotographic reproduction apparatus
US20040093995A1 (en) * 2002-07-22 2004-05-20 Bobby Hu Ratcheting wrench with quick tightening/loosening functions and fine adjusting functions
US20090297179A1 (en) * 2008-05-27 2009-12-03 Xerox Corporation Toner concentration system control with state estimators and state feedback methods
US8145078B2 (en) 2008-05-27 2012-03-27 Xerox Corporation Toner concentration system control with state estimators and state feedback methods

Also Published As

Publication number Publication date
CH438949A (de) 1967-06-30
NL6405108A (fr) 1964-11-09
DE1261758B (de) 1968-02-22
GB1066831A (en) 1967-04-26
FR1393008A (fr) 1965-03-19

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