EP0547348B1 - Elektrofotografisches Verfahren und Farbdrucker - Google Patents

Elektrofotografisches Verfahren und Farbdrucker Download PDF

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Publication number
EP0547348B1
EP0547348B1 EP92118744A EP92118744A EP0547348B1 EP 0547348 B1 EP0547348 B1 EP 0547348B1 EP 92118744 A EP92118744 A EP 92118744A EP 92118744 A EP92118744 A EP 92118744A EP 0547348 B1 EP0547348 B1 EP 0547348B1
Authority
EP
European Patent Office
Prior art keywords
color
photoconductive drum
toners
drum
magenta
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
EP92118744A
Other languages
English (en)
French (fr)
Other versions
EP0547348A3 (en
EP0547348A2 (de
Inventor
Chris A. Storlie
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.)
HP Inc
Original Assignee
Hewlett Packard 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
Application filed by Hewlett Packard Co filed Critical Hewlett Packard Co
Publication of EP0547348A2 publication Critical patent/EP0547348A2/de
Publication of EP0547348A3 publication Critical patent/EP0547348A3/en
Application granted granted Critical
Publication of EP0547348B1 publication Critical patent/EP0547348B1/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
    • G03G15/01—Apparatus for electrographic processes using a charge pattern for producing multicoloured copies
    • G03G15/0105—Details of unit
    • G03G15/0126—Details of unit using a solid developer
    • 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
    • G03G15/01—Apparatus for electrographic processes using a charge pattern for producing multicoloured copies
    • G03G15/0142—Structure of complete machines
    • G03G15/0147—Structure of complete machines using a single reusable electrographic recording member
    • G03G15/0152—Structure of complete machines using a single reusable electrographic recording member onto which the monocolour toner images are superposed before common transfer from the recording member
    • G03G15/0163—Structure of complete machines using a single reusable electrographic recording member onto which the monocolour toner images are superposed before common transfer from the recording member primary transfer to the final recording medium

Definitions

  • This invention related generally to electrophotographic color printers, also known as laser printers, and more particularly to a projection type of electrophotographic color printer using stationary positioned developer rollers.
  • the general purpose and principal object of the present invention is to provide a new and improved projection type of electrophotographic color printer which has been constructed in a novel manner to utilize stationary positioned development rollers adjacent to the surface of a photoconductive drum, such as known from EP-A-0 153 038.
  • a colored image-forming method is initiated by forming a latent image on an image retainer in the form of a rotatable drum. Then, a powdered toner is caused to fly from a developer-feeding carrier and adhere to the retainer in the presence of an oscillating electric field. Similar steps are carried out using different powdered toners to superimpose toner images of different colors on the retainer.
  • Each developer-feeding carrier has a magnet member to exert a magnetic force to the corresponding toner. In this manner, no mechanical motion other than rotational motion need be imparted to these rollers, and this approach overcomes the above described disadvantages associated with prior art carousel and cam driven developer rollers in a color printing system.
  • An object of the invention is to provide a new and improved electrophotographic color printer of the type described which is relatively straightforward and economical in construction, reliable in operation and requires a minimum of moving parts and maintenance.
  • Another object of this invention is to provide a new and improved printer and method of the type described where the position and shape of the photoconductive drum is not critical, since each color plane will be deposited accurately relative to one another.
  • an improved electrophotographic color printer and method of operation which comprises, among other things, providing color toners of cyan, yellow magenta, and black in toner compartments adjacent to the surface of a photoconductive drum; providing cyan, yellow, magenta, and black development rollers at fixed locations between these toner compartments and the photoconductive surface of the drum and at a predetermined distance from the surface of the photoconductive drum; and selectively driving the development rollers with both AC and DC signals while simultaneously rotating these development rollers within adjacent color toner compartments to thereby selectively and electrostatically project the toners from the surfaces of the development rollers onto the adjacent surface of the photoconductive drum.
  • the selectively projected color toners of cyan, yellow, magenta, and black are then developed in series on the surface of the photoconductive drum, which has been selectively discharged by the use of a laser light beam or an equivalent image development source.
  • the developed images in each color plane are then transferred in series to the surface of a print medium which is passed between the surface of the photoconductive drum and an adjacent transfer roller.
  • Figure 1 is a schematic cross section view of a color development system constructed in accordance with a preferred embodiment of the invention.
  • Figure 2 is an abbreviated isometric view which shows how the development system of Figure 1 will be positioned and operated within the housing of a color laser printer.
  • the color printer development system shown therein is designated generally as 10 and includes a fixed position or non-rotating carousel 12 having a plurality of color toner compartments 14, 16, 18, and 20 of the tapered configuration shown.
  • Each of these color toner compartments 14, 16, 18, and 20 carries, respectively, colored toners of cyan, magenta, yellow, and black and includes therein a single developer roller 22, 24, 26, and 28 rotatably mounted at a fixed location adjacent to openings 30, 32, 34, and 36 in the bottom walls of each of the tapered compartments 14, 16, 18, and 20.
  • Each of the developer rollers 22, 24, 26, and 28 are rotatably driven about their central axes 28, 40, 42, and 44, respectively, and each of these rollers is connected, respectively, to a separate voltage source 45, 47, 49, and 51.
  • the voltage produced by the voltage sources 45, 47, 49, and 51 on the selected developer of either roller 22, 24, 26, or 28 consists of an AC component and a DC component.
  • the DC component should be set to about -400 volts and between the voltage in the latent image areas of -100 volts and the non-image areas of -600 volts on the surface 48 of the photoconductive drum 50. These voltage settings will therefore drive the negatively charged toner 29, 31, 33, and 35 through the electric fields to develop in the image areas on the photoconductive drum 50.
  • the AC voltage of about 200 Hertz and 1000 Vpp is also added to enhance image development as explained in more detail by Takahaski et al in an article entitled “Mechanism of Canon Toner Projection Development", Photographic Science and Engineering , Volume 26, No. 5, September/October 1982, incorporated herein by reference.
  • Each of the developer rollers 22, 24, 26, and 28 have been carefully positioned at a fixed location above the surface 48 of the photoconductive drum 50 by a distance slightly greater than twice the thickness of the toner layers to be projected onto the outer surface 48 of the photoconductive drum 50.
  • the height of the toner on the developer rollers 22, 24, 26, and 28 is adjusted by the doctor blades 68, 70, 72, and 74, respectively, within the toner compartments 14, 16, 18, and 20.
  • the colored toners are magnetically and eletrostatically attracted to the surfaces of the developer rollers 22, 24, 26, and 28 as these rollers move through the adjacent cyan, magenta, yellow, and black toners within the compartments 14, 16, 18, and 20 and are then electrostatically projected onto the surface 48 of the photoconductive drum 50 only upon the selective application of an AC and DC signal to a desired one of these developer rollers.
  • the individual colored toners may be selectively projected onto the surface of the photoconductive drum 50 where latent images produced by a beam 52 of light from a laser source (not shown) are developed into color images.
  • a laser source not shown
  • An example of such a projection type of development system is disclosed in the above-identified Takahaski et al article and developed by Canon of Japan.
  • the color development system shown in Figure 1 will also include rotatable toner stirring blades 61, 62, 63, and 64 located as shown in each of the C, Y, M, and K compartments 14, 16, 18, and 20, respectively, and these stirring blades are operative to provide a desired amount of agitation in the toner compartments to maintain toner uniformity at the surfaces of the developer rollers 22, 24, 26, and 28.
  • the color development system in Figure 1 will also typically include a charging roller 56 for providing a desired level of electrostatic charge on the surface of the photoconductive drum 50 and for providing the desired level of electrostatic attraction for the individually projected color toners.
  • the projection system 10 in Figure 1 will further include a transfer roller 58 rotatably mounted about a central axis 60 and positioned as shown immediately adjacent to the surface 48 of the photoconductive drum 50 at a location through which the print medium 62 or other suitable intermediate transfer member (ITM-not shown) will pass.
  • a transfer roller 58 rotatably mounted about a central axis 60 and positioned as shown immediately adjacent to the surface 48 of the photoconductive drum 50 at a location through which the print medium 62 or other suitable intermediate transfer member (ITM-not shown) will pass.
  • the print medium 62 will traverse a 360° path for the transfer of each of the cyan, magenta, yellow, and black developed images in series from the surface of the photoconductive drum 50 to the medium 62.
  • the print medium 62 will be guided on each successive pass between the fuser rollers 90 and 92 shown in Figure 2 described below where the composite color image is fixed on the surface of the print medium 62 before being finally passed into an output paper collection tray or bin using well known paper motion and control techniques.
  • Suitable media control techniques for controlling paper motion during the above color printing process are disclosed in my above identified co-pending applications which are incorporated herein by reference.
  • a color electrophotographic printer housing 80 which includes an input paper tray 82 and an output paper collection bin 84 of the type currently used, for example, in Hewlett Packard's LaserJet Printers.
  • the near side wall 86 of the printer housing is shown with a section 88 thereof cut-away so that the general location of the color development system of Figure 1 therein can be seen in relation to the paper guide mechanisms used for controlling the paper motion.
  • These paper guide mechanisms include, of course, the previously described photoconductive drum 50 which is mounted adjacent to the transfer roller 58 and between which the paper 62 passes four successive times as it receives color toner from the AC and DC operated color projection rollers 22, 24, 26, and 28 previously described above with reference to Figure 1.
  • the paper guide system shown in Figure 2 will further include a pair of output fuser rollers 90 and 92 which are operative in a well known manner to serially fuse the cyan, yellow, magenta, and black color images into the paper 62 on each of four successive passes of the paper 62 along a 360° path, first around the interior surface of a first contoured paper guide member 94, then through a first pair of lower paper guide rollers 96 and 98 and then through a second pair of paper guide rollers 100 and 102 around which is positioned a second contoured paper guide member 104.
  • the media is caused to traverse over the surface of the upwardly facing paper deflection member 106 in the direction of arrow 108 and then out of the paper exit port 110 at the far end of the paper receiving bin 84.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Color Electrophotography (AREA)
  • Color, Gradation (AREA)
  • Electrophotography Using Other Than Carlson'S Method (AREA)
  • Dot-Matrix Printers And Others (AREA)

Claims (6)

  1. Ein Verfahren zum elektrophotographischen Farbdrucken mit folgenden Schritten:
    a. Bereitstellen von Farbtonern (29, 31, 33, 35) aus Cyan, Gelb, Magenta und Schwarz,
    b. Bereitstellen von einer Cyan-, einer Gelb-, einer Magenta- und einer Schwarz-Entwicklerrolle (22, 24, 26, 28) an einem festen Ort zwischen den Tonern (29, 31, 33, 35) und der Oberfläche (48) einer photoleitfähigen Trommel (50) und bei einem vorbestimmten Abstand von der Oberfläche der photoleitfähigen Trommel, und
    c. gleichzeitiges Drehen von allen Entwicklerrollen (22, 24, 26, 28), wobei die Entwicklerrollen (22, 24, 26, 28) mit separaten AC- und DC-Signalen (45, 47, 49, 51) zum Anziehen von geladenen Farbtonern zu den Oberflächen derselben selektiv getrieben werden, um dadurch die Farbtoner (29, 31, 33, 35) auf die Oberfläche der photoleitfähigen Trommel (50) selektiv zu projizieren, um eine Farbbildentwicklung auf derselben vorzubereiten.
  2. Das Verfahren gemäß Anspruch 1, das ferner ein serielles Übertragen von entwickelten Farbbildern von der Oberfläche der photoleitfähigen Trommel (50) zu der Oberfläche eines benachbarten Druckmediums (62), das zwischen der Trommel (50) und einer Übertragungsrolle (58) durchläuft, aufweist.
  3. Ein elektrophotographischer Farbdrucker mit folgenden Merkmalen:
    a. einer Einrichtung zum Bereitstellen von Farbtonern (29, 31, 33, 35) aus Cyan, Gelb, Magenta und Schwarz, und
    b. einer Cyan-, einer Gelb-, einer Magenta- und einer Schwarz-Entwicklerrolle (22, 24, 26, 28), die an einem festen Ort zwischen den Tonern und der Oberfläche einer photoleitfähigen Trommel (50) und bei einem vorbestimmten Abstand von der Oberfläche einer photoleitfähigen Trommel (50) angeordnet sind,
    c. wobei alle Entwicklerrollen im Gebrauch gleichzeitig gedreht werden, während dieselben mit separaten AC- und DC-Signalen (45, 47, 49, 51) selektiv getrieben werden, um geladene Farbtoner zu den Oberflächen derselben zuzuführen, um dadurch selektiv und elektrostatisch die Farbtoner auf die Oberfläche der photoleitfähigen Trommel (50) zu projizieren.
  4. Der Drucker gemäß Anspruch 3, der ferner eine Einrichtung zum seriellen Übertragen entwickelter Farbbilder von der Oberfläche der Trommel (50) zu einem benachbarten Druckmedium (62) aufweist, das zwischen der Trommeloberfläche (48) und einer benachbarten Übertragungsrolle (58) hindurchläuft.
  5. Der Drucker gemäß Anspruch 3 oder 4, der ferner eine Höheneinstellungsabstreichklinge (68, 70, 72, 74) aufweist, die zu jeder der Entwicklerrollen (22, 24, 26, 28) benachbart positioniert ist, zum Steuern der Mengen des Farbtoners (29, 31, 33, 35), die auf die photoleitfähige Trommel (50) übertragen werden.
  6. Der Drucker gemäß Anspruch 3, 4 oder 5, der ferner einen Druckmedienzuführweg (50, 58, 90, 92, 96, 98, 100, 102) zum Leiten der Druckmedien (62) über einen 360°-Weg für die serielle Übertragung jedes Farbbilds auf dieselben und zum Führen eines entwickelten zusammengesetzten Farbbilds auf den Druckmedien vorbei an einer Fixierrolle (90, 92) zu einem Ausgabepapiersammel-Behälter (84) oder -Fach (84) aufweist.
EP92118744A 1991-12-17 1992-11-02 Elektrofotografisches Verfahren und Farbdrucker Expired - Lifetime EP0547348B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US81223691A 1991-12-17 1991-12-17
US812236 1991-12-17

Publications (3)

Publication Number Publication Date
EP0547348A2 EP0547348A2 (de) 1993-06-23
EP0547348A3 EP0547348A3 (en) 1993-09-15
EP0547348B1 true EP0547348B1 (de) 1997-07-09

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ID=25208957

Family Applications (1)

Application Number Title Priority Date Filing Date
EP92118744A Expired - Lifetime EP0547348B1 (de) 1991-12-17 1992-11-02 Elektrofotografisches Verfahren und Farbdrucker

Country Status (3)

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EP (1) EP0547348B1 (de)
JP (1) JPH05307310A (de)
DE (1) DE69220764T2 (de)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5799230A (en) * 1997-03-24 1998-08-25 Hewlett-Packard Company Compact electrophotographic color developer module
JP2003248362A (ja) 2001-12-20 2003-09-05 Seiko Epson Corp 画像形成装置
JP2004240407A (ja) 2003-01-08 2004-08-26 Seiko Epson Corp 画像形成装置

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0370455A2 (de) * 1988-11-21 1990-05-30 Konica Corporation Farbkopiergerät mit herausnehmbarer Prozesskassette

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0153038B1 (de) * 1984-01-30 1992-04-01 Konica Corporation Verfahren zur Erzeugung von Bildern
US5047804A (en) * 1987-07-27 1991-09-10 Minolta Camera Kabushiki Kaisha Image forming apparatus having a toner replenishment control system
EP0326941B1 (de) * 1988-01-29 1994-12-14 Konica Corporation Bilderzeugungsgerät
JPH0264565A (ja) * 1988-08-31 1990-03-05 Canon Inc 画像形成装置
JPH02210466A (ja) * 1989-02-10 1990-08-21 Minolta Camera Co Ltd 作像装置
US5293206A (en) * 1989-07-11 1994-03-08 Mita Industrial Co., Ltd. Color image forming apparatus with optium operation of developing device positioning mechanism

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0370455A2 (de) * 1988-11-21 1990-05-30 Konica Corporation Farbkopiergerät mit herausnehmbarer Prozesskassette

Also Published As

Publication number Publication date
DE69220764D1 (de) 1997-08-14
DE69220764T2 (de) 1997-11-06
EP0547348A3 (en) 1993-09-15
JPH05307310A (ja) 1993-11-19
EP0547348A2 (de) 1993-06-23

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