EP0380626B1 - Entwicklermischungssteuerung für austauschbare Entwicklereinheiten - Google Patents

Entwicklermischungssteuerung für austauschbare Entwicklereinheiten Download PDF

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Publication number
EP0380626B1
EP0380626B1 EP19890908306 EP89908306A EP0380626B1 EP 0380626 B1 EP0380626 B1 EP 0380626B1 EP 19890908306 EP19890908306 EP 19890908306 EP 89908306 A EP89908306 A EP 89908306A EP 0380626 B1 EP0380626 B1 EP 0380626B1
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EP
European Patent Office
Prior art keywords
development station
toner
fresh
chamber
concentration
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
EP19890908306
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English (en)
French (fr)
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EP0380626A1 (de
Inventor
Kenneth A. Arnold
Wunan Chang
Kelly S. Robinson
Lawrence A. Hill
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.)
Eastman Kodak Co
Original Assignee
Eastman Kodak Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US07/214,967 external-priority patent/US4956668A/en
Priority claimed from US07/215,971 external-priority patent/US5043764A/en
Application filed by Eastman Kodak Co filed Critical Eastman Kodak Co
Publication of EP0380626A1 publication Critical patent/EP0380626A1/de
Application granted granted Critical
Publication of EP0380626B1 publication Critical patent/EP0380626B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
    • G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
    • G03G15/0896—Arrangements or disposition of the complete developer unit or parts thereof not provided for by groups G03G15/08 - G03G15/0894
    • 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
    • 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

  • This invention relates generally to developer mix monitors for electrostatographic machines, and more particularly to automatic monitors for replaceable development stations.
  • Electrostatographic machines generally uses a two-component developer mix comprised of a toner powder and a magnetizable carrier material.
  • toner powder has to be replenished in a quantity necessary to compensate for the consumption of toner powder used for the development of images.
  • Various automatic toner replenishment systems are known wherein a signal representative of the detected concentration of toner powder in the developer mix is compared with a reference signal corresponding to a predetermined reference toner concentration. When the detected concentration is lower than the reference concentration, replenishment occurs.
  • U.S. Patent No. 4,708,458 which issued to Ueda et al on November 24, 1987, discloses a system which, when activated at the time of replacement of the used developer mix with new mix, resets the reference signal. Thereafter, the signal representative of the detected concentration is compared to the reset reference signal.
  • EP-A-302 415 published on 08.02.89
  • a developing unit which is detachably mounted in said apparatus and is provided with an identification signal generator.
  • an identification signal generated from the generator is compared in a CPU with a reference identification data stored in a memory.
  • the generated identification signal is different from the stored reference identification data, the generated identification signal is stored as a new reference data in the memory and a toner concentration signal generated from sensor is also stored as new reference toner concentration data in the memory.
  • a problem with such apparatus is that the developing unit may be removed and replaced for maintenance or change of toner color and later reinserted. Even though the unit has previously been used, the apparatus will incorrectly assume that the current toner concentration is a factory fresh mixture.
  • a replaceable development station for use with an electrostatic machine which machine includes means for producing a toner concentration signal representative of the ratio of toner powder to carrier particles in a developer mix, means for producing a reference signal and means for selectively adjusting the reference signal until it substantially equals the toner concentration signal, said development station comprising: a first chamber containing developer mix with the mix initially having a predetermined desired toner concentration when fresh; and said development station having indicating means adjustable by the electrostatic machine for indicating whether the development station is fresh such that said indicating means can be sensed by the electrostatic machine to determine if the development station is used or fresh.
  • an electrostatographic machine comprising means for receiving a replaceable development station of the type having a first chamber containing a developer mix of carrier particles and toner powder with the mix initially having a predetermined desired toner concentration when the development station is fresh; the electrostatographic machine further comprising means for producing a toner concentration signal representative of the concentration of toner powder in the developer mix; and means for comparing a reference signal with said toner concentration signal for adjusting the concentration of toner powder in the developer mix; whereby the replaceable development station further has indicating means for indicating whether the development station is fresh; and the electrostatographic machine further has means for sensing the indicating means of a received development station for determining if the development station is used or fresh; means operable upon determining that the received development station is fresh, for adjusting the reference signal to a value related to the toner concentration signal; and means for adjusting the indicating means of a received development station to indicate that the development station is not fresh.
  • a replaceable development station is generally designated 10. It can be used to develop latent electrostatic images on a photoconductor 11 of an electrostatographic machine according to the present invention, such as a copier or printer 12, as the photoconductor is driven past the development station in the direction indicated by the arrow.
  • Station 10 comprises an elongate housing 13 that is assembled from three housing parts 14, 16 and 18 that extend the full length of the station.
  • the housing preferably has suitable guides for facilitating location of the station in a copier or printer.
  • center housing part 16 can have a pair of longitudinally extending and asymmetrically positioned guides 20 and 22 along its opposite side edges. These guides are shown received in slots 24 and 26, respectively, in copier or printer 12 as station 10 is loaded into the copier or printer.
  • Center housing part 16 has a vertically oriented wall 30 that extends the full length of the housing and is spaced from each of a pair of side walls 36 and 38 of the center housing part.
  • the top edge of wall 30 is closely adjacent the inner surface of top housing part 18, and the lower edge of wall 30 is spaced from the inner surface of bottom part 14.
  • Wall 30 divides the housing into two separate chambers 40 and 42 positioned in side-by-side relationship with the space beneath wall 30 providing access between the chambers.
  • Chamber 40 is adapted to receive a two-component developer mix comprising carrier magnetizable particles and toner powder that are to be furnished to latent images on photoconductor 11.
  • Chamber 42 holds a supply of fresh toner powder. As described later, toner powder is periodically metered from chamber 42 to chamber 40 to maintain the desired toner concentration in the developer mix.
  • Wall 38 of center housing part 16 includes a lower portion 38a that extends from approximately guide 22 to the lower end of housing part 16 and merges with a bottom wall 44 of bottom housing part 14.
  • Wall portion 38a is slanted downwardly and inwardly at a relatively steep angle. This slanted or tapered wall portion 38a facilitates the flow of toner powder from the upper portion of chamber 42 downwardly toward wall 30, thus avoiding the formation of areas where toner powder can be deposited or remain in clumps.
  • Bottom wall 44 of bottom housing part 14 defines a sump 46 for a supply of developer mix.
  • Wall 44 includes an elongate semi-cylindrical recess 48 that is located generally below and spaced from the lower end of vertical wall 30 in housing part 16.
  • the recess in wall 44 and the lower end of wall 30 define a passageway providing access for fresh toner powder to be delivered from chamber 42 to chamber 40.
  • a toner dispensing roller 50 is positioned in the passageway between the lower end of wall 30 and recess 48 in wall 44 and substantially fills that passageway.
  • dispensing roller 50 comprises an elongate cylindrical shaft 52 that is covered with a cylindrical layer of foam material 54 with the outer circumference of the foam layer being in contact with the lower end of wall 30 and the surface of recess 48 in wall 44.
  • shaft 52 project beyond the ends of foam covering 54.
  • Bearings 56 and 58 fit over the ends of shaft 52.
  • Recesses 60 and 62 in bottom housing part 14 have slots that receive annular flanges on the bearings to locate the bearings in the housing.
  • shaft 52 shown at the left in Fig. 3 projects through recesses 60 and 64 in an end wall 68 of the bottom housing part.
  • This projecting end portion of the shaft has gear teeth 70 that are engaged by a drive mechanism (not shown) inside copier or printer 12 when the station is fully inserted into the copier or printer.
  • a cover 72 of generally semi-cylindrical shape projects from end wall 74 of bottom housing part 14 and encloses the lower half of shaft 52 located in recess 62.
  • the end of shaft 52 is not exposed at the right or front end of the development station to prevent inadvertent contact by the operator of rotating shaft 52.
  • the developer mix in chamber 40 comprises carrier particles and toner powder which need to be mixed together to triboelectrically charge the particles before they are applied to a latent image on photoconductor 11.
  • a mixing wheel generally designated 80 is provided in chamber 40.
  • the mixing wheel comprises an elongate shaft 82 and a plurality of mixing blades or paddles 84 that are secured to the shaft and project radially outwardly therefrom. Three such blades 84 are illustrated in the drawings positioned at 120 degree intervals about the axis of shaft 82. Blades 84 will lift some of the developer mix and move it vertically in chamber 40 to a developer applicator generally designated 110.
  • a preferred embodiment of the applicator 110 comprises a magnetic brush having a rotatable magnetic roller 112 positioned within a stationary shell 114.
  • the magnetic roller 112 can be of a conventional construction comprising a plurality of magnetic poles that extend longitudinally along a shaft 116 with alternate poles in a circumferential direction comprising north and south poles. Rotation of the magnetic roller 112 in a clockwise direction as viewed in Figure 2 feeds developer mix upwardly to photoconductor 11.
  • the drives for dispensing roller 50, mixing wheel 80 and applicator 110 are automatically engaged with suitable drives in the copier or printer.
  • Mixing wheel 80 and magnetic roller 112 are constantly driven when developer mix is to be provided to the photoconductor.
  • the mixing wheel sweeps through sump portion 46 of chamber 40 it mixes the developer mix in that chamber and triboelectrically charges the carrier particles and toner powder.
  • the mixing wheel also delivers some of the toner mix to applicator 110, and the mix is magnetically held to the applicator by the magnets of roller 112.
  • roller 112 As roller 112 is rotated, the developer mix travels upwardly along a wall and then along wall 124 so that toner powder can contact the photoconductor as it moves past the development station for developing the latent images.
  • concentration of toner in chamber 40 reaches a predetermined low level as determined by a toner concentration monitor 125, shaft 52 of dispensing roller 50 is driven to provide new toner from chamber 42 into sump 46 for mixing with toner-depleted carrier particles.
  • the station is easily removed and disposed of, and a fresh station is placed in copier or printer 12.
  • a fuse 126 is clipped into a module 128 and mounted to bottom housing part 14, preferably by sonic welding. Electrical contacts on the bottom side of the module provide electrical access to the fuse.
  • This control circuit includes a central processor unit 130 and toner monitor 125 for detection of the toner concentration within chamber 40 of development station 10.
  • Toner monitor 125 may be chosen from several commercially available products, such as, for example, those responsive to changes in effective permeability of two component developers and manufactured by Hitachi Metals, Ltd. Toner monitor 125 emits an analog signal which is representative of the permeability in the developer mix, and thus representative of the toner concentration. The signal is digitized at an analog-to-digital converter 132 and inputted to a port of central processing unit 130.
  • Central processing unit 130 has an output port connected to a toner replenishment motor 134.
  • the toner replenishing motor is used to drive toner dispensing roller 50 ( Figure 2) in accordance with a suitable algorithm which compares the toner concentration signal from analog-to-digital converter 132 to a reference signal corresponding to a predetermined reference toner concentration.
  • the reference value is stored in memory in central processing unit 130. When the detected concentration is lower than the reference concentration, the replenishment motor is activated.
  • Resetting the reference value each time the machine is powered up could result in a reference value other than ideal. For example, one might turn the machine off after some toner depletion has occurred, but before a replenishment cycle has been effected. Upon power-up, the reference value would be changed to the lower concentration value then detected. Likewise, if the machine is turned off immediately after a replenishment, the reference value would likely be too high if it were reset in conjunction with the next power-up.
  • means are provided for marking the development station in a manner sensable by the machine to indicate that the station has previously been used.
  • the machine senses the marking means and enables the recalibration process only if a fresh development station is in use.
  • the preferred marking means includes frangible electrical fuse 126 mounted on the development station, preferably in an inaccessable position to inhibit replacement of a blown fuse.
  • a small voltage of say 5 volts DC, is connected to one side 142 of the fuse. If the voltage is sensed upon power-up at a port 144 of the central processing unit, the developer station is considered to be fresh.
  • the central processing unit turns on a transistor 146 to essentially connect the fuse to ground; increasing the current beyond the rating of the fuse (100mA in the example) and blowing the fuse.
  • the time to open the fuse is roughly ten seconds in the example. During this period, the central processing unit runs background functions, including calculation of a new reference signal corresponding to the detected toner concentration.
  • Figure 6 is a logic flowchart outlining the steps to be followed for resetting the concentration reference signal.
  • a conventional microprocessor, a programmable logic array, or discrete logic could be implemented to perform the functions shown in the flowchart.
  • the algorithm of Figure 5 passes through a connector block 150 initiating a machine warm-up cycle, and enters into a decisional block 152.
  • the logic tests the development station to determine if it is fresh. If so, the logic exits the decisional block along a path 154 into a functional block 156 to begin running the development station.
  • the logic sets the reference signal at its lowest value (functional block 158) and tests it against the signal representative of the detected toner concentration (decisional block 160). If the decision from block 160 indicates that the reference concentration is lower than the detected concentration, the logic exists the decisional block along a path 162 into a function block 164 to increment the reference signal value setting.
  • decision from decisional block 160 says “yes” instead of "no” (the toner concentration was less than the reference toner concentration)
  • the logic exits block 160 along a path 166 into a decisional block 168.
  • the reference value is stored for future use.
  • the development station is then marked as "used,” such as by blowing fuse 126, at function block 170.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Dry Development In Electrophotography (AREA)

Claims (11)

  1. Austauschbare Entwicklereinheit (10) zur Verwendung in einem elektrostatografischen Gerät (12), das eine Einrichtung (125) zum Erzeugen eines Tonerkonzentrationssignals entsprechend dem Verhältnis von Tonerpulver zu Trägerpartikeln in einer Entwicklermischung, eine Einrichtung (158) zum Erzeugen eines Referenzsignals sowie eine Einrichtung (164) zum selektiven Einstellen des Referenzsignals aufweist, bis dieses Signal im wesentlichen dem Tonerkonzentrationssignal entspricht, dadurch gekennzeichnet daß eine erste Kammer (40) vorgesehen ist, die eine Entwicklermischung enthält, die in frischem Zustand zunächst eine vorbestimmte gewünschte Tonerkonzentration besitzt, und daß die Entwicklereinheit eine Anzeigevorrichtung (126) aufweist, die von dem elektrostatografischen Gerät (12) so einstellbar ist, daß sie anzeigt, ob die Entwicklereinheit (10) unverbraucht ist, so daß die Anzeigevorrichtung (126) von dem elektrostatografischen Gerät (12) abtastbar ist und feststellt, ob die Entwicklereinheit (10) verbraucht oder unverbraucht ist.
  2. Austauschbare Entwicklereinheit nach Anspruch 1, dadurch gekennzeichnet, daß eine zweite Kammer (42) vorgesehen ist, die einen Vorrat an zur ersten Kammer (40) zu lieferndem Tonerpulver enthält, damit die gewünschte Konzentration der Tonerpartikel in der Entwicklermischung aufrechterhalten bleibt.
  3. Austauschbare Entwicklereinheit nach Anspruch 2, dadurch gekennzeichnet, daß mittels einer Zuführeinrichtung (50) Tonerpulver von der zweiten Kammer (42) zur ersten Kammer (40) bringbar ist.
  4. Austauschbare Entwicklereinheit nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß die Anzeigevorrichtung (126) aus einem zerbrechlichen Element besteht.
  5. Austauschbare Entwicklereinheit nach Anspruch 1 bis 3, dadurch gekennzeichnet, daß es sich bei der Anzeigevorrichtung (126) um eine elektrische Sicherung handelt.
  6. Austauschbare Entwicklereinheit nach Anspruch 5, dadurch gekennzeichnet, daß eine Einrichtung (170) vorgesehen ist, die vom elektrostatografischen Gerät (12) ein elektrisches Signal zum Durchbrennen der Sicherung empfängt.
  7. Elektrostatografisches Gerät (12) mit
       Mitteln (24, 26) zum Aufnehmen einer austauschbaren Entwicklereinheit (10), die eine erste Kammer (40) umfaßt, die eine Entwicklermischung aus Trägerpartikeln und Tonerpulver enthält, wobei die Mischung zunächst aus Toner in einer vorbestimmten gewünschten Konzentration besteht, wenn die Entwicklereinheit (10) unverbraucht ist,
       einer Einrichtung (125) zum Erzeugen eines Tonerkonzentrationssignals entsprechend der Konzentration des Tonerpulvers in der Entwicklermischung und mit
       einer Einrichtung (130), die ein Referenzsignal mit dem Tonerkonzentrationssignal vergleicht und die Konzentration des Tonerpulvers in der Entwicklermischung einstellt, dadurch gekennzeichnet, daß die austauschbare Entwicklereinheit (10)
       eine Anzeigevorrichtung (126) umfaßt, die anzeigt, ob die Entwicklereinheit unverbraucht ist,
       eine Einrichtung (146) aufweist, die die Anzeigevorrichtung (126) einer aufgenommenen Entwicklereinheit (10) abtastet und feststellt, ob die Entwicklereinheit (10) verbraucht oder unverbraucht ist,
       eine Einrichtung (158) umfaßt, die betriebsbereit ist, wenn sie feststellt, daß die aufgenommene Entwicklereinheit (10) unverbraucht ist, und die dann das Referenzsignal auf einen mit dem Tonerkonzentrationssignal zusammenhängenden Wert einstellt, und
       Mittel (130, 146) aufweist, die die Anzeigevorrichtung (126) einer aufgenommenen Entwicklereinheit (10) einstellen und anzeigen, daß die Entwicklereinheit (10) verbraucht ist.
  8. Elektrostatografisches Gerät nach Anspruch 7, dadurch gekennzeichnet, daß die Entwicklereinheit (10) eine Zuführeinrichtung (50) aufweist, die der Entwicklermischung Tonerpulver zuführt und dann betriebsbereit ist, wenn die Differenz zwischen dem Referenzsignal und dem Tonerkonzentrationssignal einen bestimmten Schwellenwert erreicht, und eine zweite Kammer (42) umfaßt, die einen Vorrat an zur ersten Kammer (40) zu lieferndem Tonerpulver enthält, damit die vorbestimmte Konzentration des Tonerpulvers in der Entwicklermischung aufrechterhalten bleibt, und daß durch die Zuführeinrichtung (50) Tonerpulver von der zweiten Kammer (42) zur ersten Kammer (40) bringbar ist.
  9. Elektrostatografisches Gerät nach Anspruch 7 oder 8, dadurch gekennzeichnet, daß die Einrichtung (158) zum Einstellen des Referenzsignals betriebsbereit ist, wenn das elektrostatografische Gerät (12) eingeschaltet ist.
  10. Elektrostatografisches Gerät nach Anspruch 7, dadurch gekennzeichnet, daß die Mittel (130, 146) die Anzeigevorrichtung einstellen, wenn das Gerät (12) eingeschaltet worden ist, um anzuzeigen, daß die Entwicklereinheit (10) verbraucht ist.
  11. Elektrostatografisches Gerät nach Anspruch 7 bis 10, dadurch gekennzeichnet, daß es sich bei der Anzeigevorrichtung (126) um eine Sicherung handelt.
EP19890908306 1988-07-05 1989-06-27 Entwicklermischungssteuerung für austauschbare Entwicklereinheiten Expired - Lifetime EP0380626B1 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US07/214,967 US4956668A (en) 1988-07-05 1988-07-05 Developer mix monitoring for replaceable developer stations
US214967 1988-07-05
US07/215,971 US5043764A (en) 1988-07-07 1988-07-07 Replaceable developer station having indicator for determining whether developer station is used or new
US215971 1988-07-07

Publications (2)

Publication Number Publication Date
EP0380626A1 EP0380626A1 (de) 1990-08-08
EP0380626B1 true EP0380626B1 (de) 1994-03-02

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EP19890908306 Expired - Lifetime EP0380626B1 (de) 1988-07-05 1989-06-27 Entwicklermischungssteuerung für austauschbare Entwicklereinheiten

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EP (1) EP0380626B1 (de)
JP (1) JPH03501658A (de)
DE (1) DE68913503T2 (de)
WO (1) WO1990000728A1 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100430839C (zh) * 2005-03-11 2008-11-05 富士施乐株式会社 图像形成装置及控制图像浓度的方法

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JPH02262168A (ja) * 1989-03-31 1990-10-24 Toshiba Corp 画像形成装置
US5192972A (en) * 1990-12-24 1993-03-09 Eastman Kodak Company Developer mix monitoring for color developer stations
US5309330A (en) * 1993-01-11 1994-05-03 Citation Medical Corporation Light box
JPH0887213A (ja) * 1994-09-16 1996-04-02 Konica Corp 画像形成装置
DE102005041847A1 (de) * 2005-09-02 2006-11-23 OCé PRINTING SYSTEMS GMBH Verfahren zur Einstellung eines die Tonerkonzentration eines Toner und Träger aufweisenden Entwicklergemisches messenden Tonerkonzentrationssensors in der Entwicklerstation einer elektrografischen Druck- oder Kopiereinrichtung

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Publication number Priority date Publication date Assignee Title
US4155638A (en) * 1978-03-02 1979-05-22 Eastman Kodak Company Toner concentration monitor
JPS5793373A (en) * 1980-12-01 1982-06-10 Hitachi Koki Co Ltd Detector for toner concentration
JPS6032074A (ja) * 1983-08-03 1985-02-19 Hitachi Metals Ltd 現像装置
JPS61201294A (ja) * 1985-03-05 1986-09-05 沖電気工業株式会社 液晶表示装置の製造方法
JPS61230175A (ja) * 1985-04-03 1986-10-14 Minolta Camera Co Ltd 静電潜像現像装置
JPH0711724B2 (ja) * 1985-10-30 1995-02-08 カシオ計算機株式会社 画像形成装置
US4671646A (en) * 1986-02-04 1987-06-09 Eastman Kodak Company Toner monitor control mechanism
JPS62229170A (ja) * 1986-03-29 1987-10-07 Toshiba Corp 画像形成装置
JPS6435579A (en) * 1987-07-31 1989-02-06 Toshiba Corp Image forming device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100430839C (zh) * 2005-03-11 2008-11-05 富士施乐株式会社 图像形成装置及控制图像浓度的方法

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DE68913503T2 (de) 1994-07-28
DE68913503D1 (de) 1994-04-07
EP0380626A1 (de) 1990-08-08
WO1990000728A1 (en) 1990-01-25
JPH03501658A (ja) 1991-04-11

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